95-6671. Final Water Quality Guidance for the Great Lakes System  

  • [Federal Register Volume 60, Number 56 (Thursday, March 23, 1995)]
    [Rules and Regulations]
    [Pages 15366-15425]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 95-6671]
    
    
    
          
    
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    Part III
    
    
    
    
    
    Environmental Protection Agency
    
    
    
    
    
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    40 CFR 9, 122, 123, 131, and 132
    
    
    
    Final Water Quality Guidance for the Great Lakes System; Final Rule
    
    Federal Register / Vol. 60, No. 56 / Thursday, March 23, 1995 / Rules 
    and Regulations 
    [[Page 15366]] 
    
    ENVIRONMENTAL PROTECTION AGENCY
    
    40 CFR Parts 9, 122, 123, 131, and 132
    
    [FRL-5173-7]
    RIN 2040-AC08
    
    
    Final Water Quality Guidance for the Great Lakes System
    
    AGENCY: U.S. Environmental Protection Agency.
    
    ACTION: Final rule.
    
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    SUMMARY: EPA is publishing Final Water Quality Guidance for the Great 
    Lakes System. Great Lakes States and Tribes will use the water quality 
    criteria, methodologies, policies, and procedures in the Guidance to 
    establish consistent, enforceable, long-term protection for fish and 
    shellfish in the Great Lakes and their tributaries, as well as for the 
    people and wildlife who consume them.
        The Guidance was initially developed by the Great Lakes States, 
    EPA, and other Federal agencies in open dialogue with citizens, local 
    governments, and industries in the Great Lakes ecosystem. It will 
    affect all types of pollutants, but will target especially the types of 
    long-lasting pollutants that accumulate in the food web of large lakes.
        The Guidance consists of water quality criteria for 29 pollutants 
    to protect aquatic life, wildlife, and human health, and detailed 
    methodologies to develop criteria for additional pollutants; 
    implementation procedures to develop more consistent, enforceable water 
    quality-based effluent limits in discharge permits, as well as total 
    maximum daily loads of pollutants that can be allowed to reach the 
    Lakes and their tributaries from all sources; and antidegradation 
    policies and procedures.
        Under the Clean Water Act, the States of Illinois, Indiana, 
    Michigan, Minnesota, New York, Ohio, Pennsylvania, and Wisconsin must 
    adopt provisions into their water quality standards and NPDES permit 
    programs within two years (by March 23, 1997) that are consistent with 
    the Guidance, or EPA will promulgate the provisions for them. The 
    Guidance for the Great Lakes System will help establish consistent, 
    enforceable, long-term protection from all types of pollutants, but 
    will place short-term emphasis on the types of long-lasting pollutants 
    that accumulate in the food web and pose a threat to the Great Lakes 
    System. The Guidance includes minimum water quality criteria, 
    antidegradation policies, and implementation procedures that provide a 
    coordinated ecosystem approach for addressing existing and possible 
    pollutant problems and improves consistency in water quality standards 
    and permitting procedures in the Great Lakes System. In addition, the 
    Guidance provisions help establish consistent goals or minimum 
    requirements for Remedial Action Plans (RAPs) and Lakewide Management 
    Plans (LaMPs) that are critical to the success of international multi-
    media efforts to protect and restore the Great Lakes ecosystem.
    
    EFFECTIVE DATE: April 24, 1995.
    
    ADDRESSES: The public docket for this rulemaking, including applicable 
    Federal Register documents, public comments in response to these 
    documents, the Final Water Quality Guidance for the Great Lakes System, 
    Response to Comments Document, other major supporting documents, and 
    the index to the docket are available for inspection and copying at 
    U.S. EPA Region 5, 77 West Jackson Blvd., Chicago, IL 60604 by 
    appointment only. Appointments may be made by calling Wendy Schumacher 
    (telephone 312-886-0142).
        Information concerning the Great Lakes Initiative (GLI) 
    Clearinghouse is available from Ken Fenner, Water Quality Branch Chief, 
    (WQS-16J), U.S. EPA Region 5, 77 W. Jackson Blvd., Chicago, IL 60604 
    (312-353-2079).
        Copies of the Information Collection Request for the Guidance are 
    available by writing or calling Sandy Farmer, Information Policy 
    Branch, EPA, 401 M St., S.W. (Mail Code 2136), Washington, DC 20460 
    (202-260-2740).
        Selected documents supporting the Guidance are also available for 
    viewing by the public at locations listed in section XI of the 
    preamble.
        Selected documents supporting the Guidance are available by mail 
    upon request for a fee. Selected documents are also available in 
    electronic format at no incremental cost to users of the Internet. See 
    section XI of the preamble for additional information.
    
    FOR FURTHER INFORMATION CONTACT: Kenneth A. Fenner, Water Quality 
    Branch Chief (WQS-16J), U.S. EPA Region 5, 77 W. Jackson Blvd., 
    Chicago, IL 60604 (312-353-2079).
    
    SUPPLEMENTARY INFORMATION
    
    Preamble Outline
    
    I. Introduction
    II. Background
    III. Purpose of the Guidence
        A. Use the Best Available Science to Protect Human Health, 
    Aquatic Life, and Wildlife
        B. Recognize the Unique Nature of the Great Lakes Basin 
    Ecosystem
        C. Promote Consistency in Standards and Implementation 
    Procedures While Allowing Appropriate Flexibility to States and 
    Tribes
        D. Establish Equitable Strategies to Control Pollution Sources
        E. Promote Pollution Prevention Practices
        F. Provide Accurate Assessment of Costs and Benefits
    IV. Sumarry of the Final Guidance
        A. Water Quality Criteria and Methodologies
        1. Protection of Aquatic Life
        2. Protection of Human Health
        3. Protection of Wildlife
        4. Bioaccumulation Methodology
        B. Implementation Procedures
        1. Site-Specific Modifications
        2. Variances from Water Quality Standards for Point Sources
        3. TMDLs and Mixing Zones
        4. Additivity
        5. Determining the Need for WQBELs (Reasonable Potential)
        6. Intake Pollutants
        7. WET
        8. Loading Limits
        9. Levels of Quantification
        10. Compliance Schedules
        C. Antidegradation Provisions
        D. Regulatory Requirements
    V. Costs, Cost-Effectiveness and Benefits
        A. Costs
        B. Cost-Effectiveness
        C. Benefits
    VI. Regulatory Flexibility Act
    VII. Enhancing the Intergovernmental Partnership Under Executive 
    Order 12875
    VIII. Paperwork Reduction Act
    IX. Endangered Species Act
    X. Judicail Review of Provisions not Amended
    XI. Supporting Documents
    
    I. Introduction
    
        Section 118(c)(2) of the Clean Water Act (CWA) (Pub. L. 92-500 as 
    amended by the Great Lakes Critical Programs Act of 1990 (CPA), Pub. L. 
    101-596, November 16, 1990) required EPA to publish proposed and final 
    water quality guidance on minimum water quality standards, 
    antidegradation policies, and implementation procedures for the Great 
    Lakes System. In response to these requirements, EPA published the 
    Proposed Water Quality Guidance for the Great Lakes System (proposed 
    Guidance) in the Federal Register on April 16, 1993 (58 FR 20802). EPA 
    also published four subsequent documents in the Federal Register 
    identifying corrections and requesting comments on additional related 
    materials (April 16, 1993, 58 FR 21046; August 9, 1993, 58 FR 42266; 
    September 13, 1993, 58 FR 47845; and August 30, 1994, 59 FR 44678). EPA 
    received over 26,500 pages of comments, data, and information from over 
    6,000 commenters in response to [[Page 15367]] these documents and from 
    meetings with members of the public.
        After reviewing and analyzing the information in the proposal and 
    these comments, EPA has developed the Final Water Quality Guidance for 
    the Great Lakes System (final Guidance), published in this document and 
    codified in 40 CFR part 132, which includes six appendixes of detailed 
    methodologies, policies, and procedures. This preamble describes the 
    background and purpose of the final Guidance, and briefly summarizes 
    the major provisions. Detailed discussion of EPA's reasons for issuing 
    the final Guidance, analysis of comments and issues, description of 
    specific changes made to the proposed Guidance, and further description 
    of the final Guidance, are provided in ``Final Water Quality Guidance 
    for the Great Lakes System: Supplementary Information Document'' (SID), 
    (EPA, 1995, 820-B-95-001) and in additional technical and supporting 
    documents which are available in the docket for this rulemaking. Copies 
    of the SID and other supporting documents are also available from EPA 
    in electronic format, or in printed form for a fee upon request; see 
    section XI of this preamble.
    
    II. Background
    
        The Great Lakes are one of the outstanding natural resources of the 
    world. They have played a vital role in the history and development of 
    the United States and Canada, and have physical, chemical, and 
    biological characteristics that make them a unique ecosystem. The Great 
    Lakes themselves--Lakes Superior, Huron, Michigan, Erie and Ontario and 
    their connecting channels--plus all of the streams, rivers, lakes and 
    other bodies of water that are within the drainage basin of the Lakes 
    collectively comprise the Great Lakes System.
        The System spans over 750 miles across eight States--New York, 
    Pennsylvania, Ohio, Michigan, Indiana, Illinois, Wisconsin and 
    Minnesota--and the Province of Ontario. The Lakes contain approximately 
    18 percent of the world's and 95 percent of the United States' fresh 
    surface water supply. The Great Lakes are a source of drinking water 
    and energy, and are used for recreational, transportation, agricultural 
    and industrial purposes by the more than 46 million Americans and 
    Canadians who inhabit the Great Lakes region, including 29 Native 
    American tribes. Over 1,000 industries and millions of jobs are 
    dependent upon water from the Great Lakes. The Great Lakes System also 
    supports hundreds of species of aquatic life, wildlife and plants along 
    more than 4,500 miles of coastline which boast six National Parks and 
    Lakeshores, six National Forests, seven National Wildlife Refuges, and 
    hundreds of State parks, forests and sanctuaries.
        Because of their unique features, the Great Lakes are viewed as 
    important to the residents of the region, and to the Nation as a whole. 
    The natural resources of the region have contributed to the development 
    of its economy. The Lakes' natural beauty and aquatic resources form 
    the basis for heavy recreational activity. The Great Lakes Basin 
    Ecosystem--the interacting components of air, land, water and living 
    organisms, including humans, that live within the Great Lakes drainage 
    basin--is a remarkably diverse and unique ecosystem important in the 
    global ecology.
        In the past few decades, the presence of environmental contaminants 
    in the Great Lakes has been of significant concern. In spite of the 
    fact that the Great Lakes contain 5,500 cubic miles of water that cover 
    a total surface area of 94,000 square miles, they have proved to be 
    sensitive to the effects of pollutants that accumulate in them. The 
    internal responses and processes that operate in the Great Lakes 
    because of their depth and long hydraulic residence times cause 
    pollutants to recycle between biota, sediments and the water column.
        The first major basin-wide environmental problem in the Great Lakes 
    emerged in the late 1960s, when increased nutrients had dramatically 
    stimulated the growth of green plants and algae, reduced dissolved 
    oxygen levels, and accelerated the process of eutrophication. As oxygen 
    levels continued to drop, certain species of insects and fish were 
    displaced from affected areas of the Great Lakes Basin Ecosystem. 
    Environmental managers determined that a lakewide approach was 
    necessary to adequately control accelerated eutrophication. From the 
    late 1960s through the late 1970s, United States and Canadian 
    regulatory agencies agreed on measures to limit the loadings of 
    phosphorus, including effluent limits on all major municipal sewage 
    treatment facilities, limitations on the phosphorus content in 
    household detergents, and reductions in nonpoint source runoff 
    loadings. As a result of all of these efforts, open lake phosphorus 
    concentrations have declined, and phosphorus loadings from municipal 
    sewage treatment facilities have been reduced by an estimated 80 to 90 
    percent. These reductions have resulted in dramatic improvements in 
    nearshore water quality and measurable improvements in open lake 
    conditions.
        More recently, scientists and public leaders have reached a general 
    consensus that the presence of environmentally persistent, 
    bioaccumulative contaminants is a serious environmental threat to the 
    Great Lakes Basin Ecosystem. Beginning in 1963, adverse environmental 
    impacts in the form of poor reproductive success and high levels of the 
    pesticide DDT were observed in herring gulls in Lake Michigan. Through 
    ongoing research, scientists have detected 362 contaminants in the 
    Great Lakes System. Of these, approximately one third have 
    toxicological data showing that they can have acute or chronic toxic 
    effects on aquatic life, wildlife and/or human health. Chemicals that 
    have been found to bioaccumulate at levels of concern in the Great 
    Lakes include, but are not limited to, polychlorinated biphenyls 
    (PCBs), mercury, DDT, dioxin, chlordane, and mirex. The main route of 
    exposure to these chemicals for humans is through the consumption of 
    Great Lakes fish.
        Potential adverse human health effects by these pollutants 
    resulting from the consumption of fish include both the increased risk 
    of cancer and the potential for systemic or noncancer risks such as 
    kidney damage. EPA has calculated health risks to populations in the 
    Great Lakes basin from consumption of contaminated fish based on 
    exposure to eight bioaccumulative pollutants: chlordane, DDT, dieldrin, 
    hexachlorobenzene, mercury, PCBs, 2,3,7,8-TCDD, and toxaphene. These 
    chemicals were chosen based on their potential to cause adverse human 
    health effects (i.e., cancer or disease) and the availability of 
    information on fish tissue contaminant concentrations from the Great 
    Lakes.
        Based on these data, EPA estimates that the lifetime cancer risks 
    for Native Americans in the Great Lakes System due to ingestion of 
    contaminated fish at current concentrations range from 1.8  x  
    10-\3\ (Lake Superior) (1.8 in one thousand) to 3.7  x  
    10-\2\ (Lake Michigan) (3.7 in 100). Estimated risks to low income 
    minority sport anglers range from 2.5  x  10-\3\ (2.5 in one 
    thousand) (Lake Superior) to 1.2  x  10-\2\ (1.2 in 100) (Lake 
    Michigan). Estimated risks for other sport anglers range from 9.7  x  
    10-\4\ (9.7 in ten thousand) (Lake Superior) to 4.5  x  
    10-\3\ (4.5 in one thousand) (Lake Michigan). (See section I.B.2.a 
    of the SID.) In comparison, EPA has long maintained that 1  x  
    10-\4\ (one in ten thousand) to 1  x  10-\6\ (one in 1 
    million) is an appropriate range of risk to protect human health. 
    [[Page 15368]] 
        EPA also estimates a high potential risk of systemic (noncancer) 
    injury to populations in the Great Lakes basin due to ingestion of fish 
    contaminated with these pollutants at current concentrations. The 
    systemic adverse health effects associated with the assessed 
    contaminants are described in section I.B of the SID.
        Although the Great Lakes States and EPA have moved forward to deal 
    with these problems, control of persistent, bioaccumulative pollutants 
    proved to be more complex and difficult than dealing with nutrients. As 
    a result, inconsistencies began to be apparent in the ways various 
    States developed and implemented controls for the pollutants. By the 
    mid-1980s, such inconsistencies became of increasing concern to EPA and 
    State environmental managers.
        EPA began the Great Lakes Water Quality Initiative (``Initiative'') 
    in cooperation with the Great Lakes States to establish a consistent 
    level of environmental protection for the Great Lakes ecosystem, 
    particularly in the area of State water quality standards and the 
    National Pollutant Discharge Elimination System (NPDES) programs. In 
    the spring of 1989, the Council of Great Lakes Governors unanimously 
    agreed to participate in the Initiative with EPA, because the 
    Initiative supported the principles and goals of the Great Lakes Toxic 
    Substances Control Agreement (Governors' Agreement). Signed in 1986 by 
    the Governors of all eight Great Lakes States, the Governors' Agreement 
    affirmed the Governors' intention to manage and protect the resources 
    of the Great Lakes basin through the joint pursuit of unified and 
    cooperative principles, policies and programs enacted and adhered to by 
    each Great Lakes State.
        The Initiative provided a forum for a regional dialogue to 
    establish minimum requirements that would reduce disparities between 
    State water quality controls in the Great Lakes basin. The scope of the 
    Initiative included development of proposed Great Lakes water quality 
    guidance--Great Lakes-specific water quality criteria and methodologies 
    to protect aquatic life, wildlife and human health, procedures to 
    implement water quality criteria, and an antidegradation policy.
        Three committees were formed to oversee the Initiative. A Steering 
    Committee (composed of directors of water programs from the Great Lakes 
    States' environmental agencies and EPA's National and Regional Offices) 
    discussed policy, scientific, and technical issues, directed the work 
    of the Technical Work Group and ratified final proposals. The Technical 
    Work Group (consisting of technical staff from the Great Lakes States' 
    environmental agencies, EPA, the U.S. Fish and Wildlife Service, and 
    the National Park Service) prepared proposals on elements of the 
    Guidance for consideration by the Steering Committee. The Public 
    Participation Group (consisting of representatives from environmental 
    groups, municipalities, industry and academia) observed the 
    deliberations of the other two committees, advised them of the public's 
    concerns, and kept its various constituencies apprised of ongoing 
    activities and issues. These three groups were collectively known as 
    the Initiative Committees. From the start, one goal of the Initiative 
    Committees was to develop the Guidance elements in an open public 
    forum, drawing upon the extensive expertise and interest of individuals 
    and groups within the Great Lakes community.
        The Initiative efforts were well underway when Congress amended 
    section 118 of the CWA in 1990 through the CPA. The general purpose of 
    these amendments was to improve the effectiveness of EPA's existing 
    programs in the Great Lakes by identifying key treaty provisions agreed 
    to by the United States and Canada in the Great Lakes Water Quality 
    Agreement (GLWQA), imposing statutory deadlines for the implementation 
    of these key activities, and increasing Federal resources for program 
    operations in the Great Lakes System.
        Section 118(c)(2) requires EPA to publish proposed and final water 
    quality guidance for the Great Lakes System. This Guidance must conform 
    with the objectives and provisions of the GLWQA (a binational agreement 
    establishing common water quality objectives for the Great Lakes) and 
    be no less restrictive than provisions of the CWA and National water 
    quality criteria and guidance. The Guidance must specify minimum 
    requirements for the waters in the Great Lakes System in three areas: 
    (1) water quality standards (including numerical limits on pollutants 
    in ambient Great Lakes waters to protect human health, aquatic life and 
    wildlife); (2) antidegradation policies; and (3) implementation 
    procedures.
        The Great Lakes States must adopt water quality standards, 
    antidegradation policies and implementation procedures for waters 
    within the Great Lakes System which are consistent with the final 
    Guidance within two years of EPA's publication. In the absence of such 
    action, EPA is required to promulgate any necessary requirements within 
    that two-year period. In addition, when an Indian Tribe is authorized 
    to administer the NPDES or water quality standards program in the Great 
    Lakes basin, it will also need to adopt provisions consistent with the 
    final Guidance into their water programs.
        On December 6, 1991, the Initiative Steering Committee unanimously 
    recommended that EPA publish the draft Guidance ratified by that group 
    in the Federal Register for public review and comment. The agreement 
    that the draft Great Lakes Guidance was ready for public notice did not 
    represent an endorsement by every State of all of the specific 
    proposals. Rather, all parties agreed on the importance of proceeding 
    to publish the draft Great Lakes Guidance in order to further solicit 
    public comment. State Steering Committee members indicated their intent 
    to develop and submit specific comments on the proposed Guidance during 
    the public comment period. EPA worked to convert the agreements reached 
    in principle by the Steering Committee into a formal package suitable 
    for publication in the Federal Register as proposed Guidance. EPA 
    generally used the draft proposal ratified by the Steering Committee as 
    the basis for preparing the Federal Register proposal package. 
    Modifications were necessary, however, to reflect statutory and 
    regulatory requirements and EPA policy considerations, to propose 
    procedures for State and Tribal adoption of the final Guidance, to 
    provide suitable discussion of various alternative options, and to 
    accommodate necessary format changes. Where modifications were made, 
    the preamble to the proposal described both the modification and the 
    original Steering Committee-approved guidelines, and invited public 
    comment on both. All elements approved by the Steering Committee were 
    either incorporated in the proposed rule or discussed in the preamble 
    to the proposal.
    
    III. Purpose of the Guidance
    
        The final Guidance represents a milestone in the 30 years of effort 
    described above on the part of the Great Lakes stakeholders to define 
    and apply innovative, comprehensive environmental programs in 
    protecting and restoring the Great Lakes. In particular, this 
    publication of the final Guidance culminates six years of intensive, 
    cooperative effort that included participation by the eight Great Lakes 
    States, the environmental community, academia, industry, municipalities 
    and EPA Regional and National offices. [[Page 15369]] 
        The final Guidance will help establish consistent, enforceable, 
    long-term protection with respect to all types of pollutants, but will 
    place short-term emphasis on the types of long-lasting pollutants that 
    accumulate in the food web and pose a threat to the Great Lakes System. 
    The final Guidance will establish goals and minimum requirements that 
    will further the next phase of Great Lakes programs, including the 
    Great Lakes Toxic Reduction Effort's integrated, multi-media ecosystem 
    approach.
        EPA and State development of the Guidance--from drafting through 
    proposal and now final publication--was guided by several general 
    principles that are discussed below.
    
    A. Use the Best Available Science to Protect Human Health, Aquatic 
    Life, and Wildlife
    
        EPA and the Initiative Committees have been committed throughout 
    the Initiative to using the best available science to develop programs 
    to protect the Great Lakes System. In the 1986 Governors' Agreement, 
    the Governors of the Great Lakes States recognized that the problem of 
    persistent toxic substances was the foremost environmental issue 
    confronting the Great Lakes. They also recognized that the regulation 
    of toxic contaminants was scientifically complex because the pollutants 
    are numerous, their pathways into the Lakes are varied, and their 
    effects on the environment, aquatic life and human health are not 
    completely understood. Based on the importance of the Great Lakes Basin 
    Ecosystem and the documented adverse effects from toxic contamination, 
    however, the Governors directed their environmental administrators to 
    jointly develop an agreement and procedure for coordinating the control 
    of toxic releases and achieving greater uniformity of regulations 
    governing such releases within the Great Lakes basin.
        As discussed further above, the Initiative was subsequently created 
    to begin work on these goals. EPA and the Great Lakes States, with 
    input from interested parties in the basin, began collecting and 
    analyzing data, comparing regulatory requirements and technical 
    guidance in their various jurisdictions, and drafting specific 
    methodologies and procedures to control the discharge of toxic 
    contaminants. The provisions of the final Guidance were based in large 
    part on these prior efforts of the Initiative Committees, and 
    incorporate the best available science to protect human health, 
    wildlife and aquatic life in the Great Lakes System. For example, the 
    final Guidance includes new criteria and a methodology developed by the 
    Initiative Committees to specifically protect wildlife; incorporates 
    recent data on the bioavailability of metals into the aquatic life 
    criteria and methodologies; incorporates Great Lakes-specific data on 
    fish consumption rates and fish lipid contents into the human health 
    criteria; and provides a methodology to determine the bioaccumulation 
    properties of individual pollutants. Additionally, EPA understands that 
    the science of risk assessment is rapidly improving. Therefore, in 
    order to ensure that the scientific basis for the criteria 
    methodologies is always current and peer reviewed, EPA will review the 
    methodologies and revise them as appropriate every three years.
    
    B. Recognize the Unique Nature of the Great Lakes Basin Ecosystem
    
        The final Guidance also reflects the unique nature of the Great 
    Lakes Basin Ecosystem by establishing special provisions for chemicals 
    of concern. EPA and the Great Lakes States believe it is reasonable and 
    appropriate to establish special provisions for the chemicals of most 
    concern because of the physical, chemical and biological 
    characteristics of the Great Lakes System, and the documented 
    environmental harm to the ecosystem from the past and continuing 
    presence of these types of pollutants. The Initiative Committees 
    devoted considerable effort to identifying the chemicals of most 
    concern to the Great Lakes System--persistent, bioaccumulative 
    pollutants termed ``bioaccumulative chemicals of concern (BCCs)''--and 
    developing the most appropriate criteria, methodologies, policies, and 
    procedures to address them. The special provisions for BCCs, initially 
    developed by the Initiative Committees and incorporated into the final 
    Guidance, include antidegradation procedures, to ensure that future 
    problems are minimized; general phase-out and elimination of mixing 
    zones for BCCs, except in limited circumstances, to reduce their 
    overall loadings to the Lakes; more extensive data generation 
    requirements to ensure that they are not under-regulated for lack of 
    data; and development of water quality criteria that will protect 
    wildlife that feed on aquatic prey.
        The final Guidance is designed not only to begin to address 
    existing problems, but also to prevent emerging and potential problems 
    posed by additional chemicals in the future which may damage the 
    overall health of the Great Lakes. The experience with such pollutants 
    as DDT and PCBs indicates that it takes many decades to overcome the 
    damage to the ecosystem caused by even short-term discharges, and that 
    prevention would have been dramatically less costly than clean-up. 
    Issuance of the final Guidance alone will not solve the existing long-
    term problems in the Great Lakes System from these contaminants. Full 
    implementation of provisions consistent with the final Guidance will, 
    however, provide a coordinated ecosystem approach for addressing 
    possible pollutant problems before they produce adverse and long-
    lasting basin-wide impacts, rather than waiting to see what the future 
    impacts of the pollutants might be before acting to control them. The 
    comprehensive approach used in the development of the final Guidance 
    provides regulatory authorities with both remedial and preventive ways 
    of gauging the actions and potential effects of chemical stressors upon 
    the Great Lakes Basin Ecosystem. The methodologies, policies and 
    procedures contained in the final Guidance provide mechanisms for 
    appropriately addressing both pollutants that have been or may in the 
    future be documented as chemicals of concern.
    
    C. Promote Consistency in Standards and Implementation Procedures While 
    Allowing Appropriate Flexibility to States and Tribes
    
        Promoting consistency in standards and implementation procedures 
    while providing for appropriate State flexibility was the third 
    principle in State and EPA development of the final Guidance. The 
    underlying rationale for the Governors' Agreement, the Initiative, and 
    the requirements set forth in the CPA was a recognition of the need to 
    promote consistency through adoption of minimum water quality 
    standards, antidegradation policies, and implementation procedures by 
    Great Lakes States and Tribes to protect human health, aquatic life and 
    wildlife. Although provisions in the CWA provide for the adoption of 
    and periodic revisions to State water quality criteria, such provisions 
    do not necessarily ensure that water quality criteria of adjoining 
    States are consistent within a shared water body. For example, ambient 
    water quality criteria in place in six of the eight Great Lakes States 
    to protect aquatic life from acute effects range from 1.79 g/L 
    to 15.0 g/L for cadmium, and from 0.21 g/L to 1.33 
    g/L for dieldrin. Other examples of variations in acute 
    aquatic life criteria include nickel, which ranges from 290.30 
    g/L to 852.669 g/L; lindane, [[Page 15370]] with a 
    range of no criteria in place to 1.32 g/L; and mercury, 
    ranging from 0.5 g/L to 2.4 g/L. Similar ranges and 
    disparities exist for chronic aquatic life criteria, and for water 
    quality criteria to protect human health.
        Disparities also exist among State procedures to translate water 
    quality criteria into individual discharge permits. Wide variations 
    exist, for example, in procedures for the granting of mixing zones, 
    interpretation of background levels of pollutants, consideration of 
    pollutants present in intake waters, controls for pollutants present in 
    concentrations below the level of detection, and determination of 
    appropriate levels for pollutants discharged in mixtures with other 
    pollutants. Additionally, when addressing the accumulation of chemicals 
    by fish that will be consumed by humans and wildlife, some States 
    consider accumulation through multiple steps in the food chain 
    (bioaccumulation) while others consider only the single step of 
    concentration from the water column (bioconcentration). Further 
    disparities exist in different translator methodologies in deriving 
    numeric values for implementing narrative water quality criteria; 
    different assumptions when calculating total maximum daily loads 
    (TMDLs) and wasteload allocations (WLAs), including different 
    assumptions about background concentrations, mixing zones, receiving 
    water flows, or environmental fate; and different practices in deciding 
    what pollutants need to be regulated in a discharge, what effect 
    detection limits have on compliance determinations, and how to develop 
    whole effluent toxicity limitations.
        These inconsistencies in State standards and implementation 
    procedures have resulted in the disparate regulation of point source 
    discharges. In the Governors' Agreement, the Governors recognized that 
    the water resources of the basin transcend political boundaries and 
    committed to taking steps to manage the Great Lakes as an integrated 
    ecosystem. The Great Lakes States, as participants in the Initiative 
    Committees, recommended provisions, based on their extensive experience 
    in administering State water programs and knowledge of the significant 
    differences in these programs within the basin, that were ultimately 
    included in the proposed Guidance. The final Guidance incorporates the 
    work begun by the Initiative Committees to identify these disparities 
    and improve consistency in water quality standards and permit 
    procedures in the Great Lakes System.
        Although improved consistency in State water programs is a primary 
    goal of the final Guidance, it is also necessary to provide appropriate 
    flexibility to States and Tribes in the development and implementation 
    of water programs. In overseeing States' implementation of the CWA, EPA 
    has found that reasonable flexibility is not only necessary to 
    accommodate site-specific situations and unforeseen circumstances, but 
    is also appropriate to enable innovation and progress as new approaches 
    and information become available. Many commenters, including the Great 
    Lakes States, urged EPA to evaluate the appropriate level of 
    flexibility provided to States and Tribes in the proposed Guidance 
    provisions. EPA reviewed all sections of the proposed Guidance and all 
    comments received to determine the appropriate level of flexibility 
    needed to address these concerns while still providing a minimum level 
    of consistency between the State and Tribal programs. Based on this 
    review, the final Guidance provides flexibility for State and Tribal 
    adoption and implementation of provisions consistent with the final 
    Guidance in many areas, including the following:
    
    --Antidegradation: Great Lakes States and Tribes may develop their own 
    approaches for implementing the prohibition against deliberate actions 
    of dischargers that increase the mass loading of BCCs without an 
    approved antidegradation demonstration. Furthermore, States and Tribes 
    have flexibility in adopting antidegradation provisions regarding non-
    BCCs.
    --TMDLs: Great Lakes States and Tribes may use assessment and 
    remediation plans for the purposes of appendix F to part 132 if the 
    State or Tribe certifies that the assessment and remediation plan meets 
    certain TMDL-related provisions in the final Guidance and public 
    participation requirements applicable to TMDLs, and if EPA approves 
    such plan. Thus, States have the flexibility in many cases to use 
    LAMPs, RAPs and State Water Quality Management Plans in lieu of TMDLs.
    --Intake Credits: Great Lakes States and Tribes may consider the 
    presence of intake water pollutants in establishing water quality-based 
    effluent limits (WQBELs) in accordance with procedure 5 of appendix F.
    --Site-Specific Modifications: Great Lakes States and Tribes may adopt 
    either more or less stringent modifications to human health, wildlife, 
    and aquatic life criteria and bioaccumulation factors (BAFs) based on 
    site-specific circumstances specified in procedure 1 of appendix F. All 
    criteria, however, must be sufficient not to cause jeopardy to 
    threatened or endangered species listed or proposed to be listed under 
    the Federal Endangered Species Act.
    --Variances: Great Lakes States and Tribes may grant variances from 
    water quality standards based on the factors identified in procedure 2 
    of appendix F.
    --Compliance Schedules: Great Lakes States and Tribes may allow 
    existing Great Lakes dischargers additional time to comply with permit 
    limits in order to collect data to derive new or revised Tier I 
    criteria and Tier II values in accordance with procedure 9 of appendix 
    F.
    --Mixing Zones: Great Lakes States and Tribes may authorize mixing 
    zones for existing discharges of BCCs after the 10-year phase-out 
    period in accordance with procedure 3.B of appendix F, if the 
    permitting authority determines, among other things, that the 
    discharger has reduced its discharge of the BCC for which a mixing zone 
    is sought to the maximum extent possible. Water conservation efforts 
    that result in overall reductions of BCCs are also allowed even if they 
    result in higher effluent concentrations.
    --Scientific Defensibility Exclusion: Great Lakes States and Tribes may 
    apply alternate procedures consistent with Federal, State, and Tribal 
    requirements upon demonstration that a provision in the final Guidance 
    would not be scientifically defensible if applied to a particular 
    pollutant in one or more sites. This provision is in Sec. 132.4(h) of 
    the final Guidance.
    --Reduced Detail: In many instances, EPA has revised the proposed 
    Guidance to reduce the amount of detail in the provisions without 
    sacrificing the objectives of the provisions. Examples of such 
    revisions include simplification of procedures for developing TMDLs in 
    procedure 3 of appendix F, and simplification of procedures for 
    determining reasonable potential to exceed water quality standards in 
    procedure 5.B of appendix F.
    --Other Provisions: Flexibility is also present in provisions for the 
    exercise of best professional judgment by the Great Lakes States and 
    Tribes when implementing many individual provisions in the final 
    Guidance including: determining the appropriate uncertainty factors in 
    the human health and wildlife criteria methodologies; selection of data 
    sets for establishing water quality criteria; identifying reasonable 
    and prudent [[Page 15371]] measures in antidegradation provisions; and 
    specifying appropriate margins of safety when developing TMDLs. In all 
    cases, of course, State and Tribal provisions would need to be 
    scientifically defensible and consistent with all applicable regulatory 
    requirements.
    
    D. Establish Equitable Strategies to Control Pollution Sources
    
        Many commenters argued that the proposed Guidance unfairly focused 
    on point source discharges. They asserted that nonpoint sources or 
    diffuse sources of pollution, such as air emissions, are responsible 
    for most of the loadings of some pollutants of concern in the Great 
    Lakes, that increased regulation of point sources will be inequitable 
    and expensive, and that the final Guidance will not result in any 
    environmental improvement given the large, continuing contribution of 
    toxic pollutants by nonpoint sources.
        EPA recognizes that regulation of point source discharges alone 
    cannot address all existing or future environmental problems from toxic 
    pollutants in the Great Lakes. In addition to discharges from point 
    sources, toxic pollutants are also contributed to the Great Lakes from 
    industrial and municipal emissions to the air, resuspension of 
    pollutants from contaminated sediments, urban and agricultural runoff, 
    hazardous waste and Superfund sites, and spills. Restoration and 
    maintenance of a healthy ecosystem will require significant efforts in 
    all of these areas. EPA, Canada and the Great Lakes States and Tribes 
    are currently implementing or developing many voluntary and regulatory 
    programs to address these and other nonpoint sources of environmental 
    contaminants in the Great Lakes.
        Additionally, EPA intends to use the scientific data developed in 
    the final Guidance and new or revised water quality criteria 
    subsequently adopted by Great Lakes States and Tribes in evaluating and 
    determining appropriate levels of control in other environmental 
    programs. For example, EPA's future biennial reports under section 
    112(m) of the Clean Air Act will consider the extent to which air 
    discharges cause or contribute to exceedances of water quality criteria 
    in assessing whether additional air emission standards or control 
    measures are necessary to prevent serious adverse effects. Similarly, 
    once provisions consistent with the final Guidance are adopted by the 
    Great Lakes States or Tribes, they will serve as applicable or relevant 
    and appropriate requirements (ARARs) for on-site responses under the 
    Comprehensive Environmental Response, Compensation and Liability Act 
    (CERCLA). EPA will also consider the data and criteria developed for 
    the final Guidance, including the information on BCCs, in developing or 
    evaluating LaMPs and RAPs under section 118 of the CWA and Article VI, 
    Annex 2 of the GLWQA; determination of corrective action requirements 
    under sections 3004(u), 3008(h), or 7003 of the Solid Waste Disposal 
    Act; new or existing chemical reviews under the Toxic Substances 
    Control Act (TSCA); pesticide reviews under the Federal Insecticide, 
    Fungicide and Rodenticide Act (FIFRA); and reporting requirements for 
    toxic releases under the Emergency Planning and Community Right-to-Know 
    Act (EPCRA).
        The final Guidance also includes provisions to address the 
    contribution of pollutants by nonpoint sources. First, the water 
    quality criteria to protect human health, wildlife and aquatic life, 
    and the antidegradation provisions apply to the waters in the Great 
    Lakes System regardless of whether discharges to the water are from 
    point or nonpoint sources. Accordingly, any regulatory programs for 
    nonpoint sources that require compliance with water quality standards 
    would also be subject to the criteria and antidegradation provisions of 
    the final Guidance once they are adopted into State or Tribal 
    standards.
        Second, several elements of the final Guidance would, after State, 
    Tribal or Federal promulgation, require or allow permitting authorities 
    to consider the presence of pollutants in ambient waters--including 
    pollutants from nonpoint source dischargers--in establishing WQBELs for 
    point sources. For example, permit authorities may consider the 
    presence of other point or nonpoint source discharges when evaluating 
    whether to grant a variance from water quality criteria. Additionally, 
    the provisions for TMDLs address nonpoint sources by specifying that 
    the loading capacity of a receiving water that does not meet water 
    quality standards for a particular pollutant be allocated, where 
    appropriate, among nonpoint as well as point sources of the pollutant, 
    including, at a minimum, a margin of safety to account for technical 
    uncertainties in establishing the TMDL. The development of TMDLs is the 
    preferred mechanism for addressing equitable division of the loading 
    capacities of these nonattained waters. Because TMDLs have not been 
    completed for most nonattained waters, however, the final Guidance 
    promotes the development of TMDLs through a phased approach, where 
    appropriate, and provides for short-term regulatory relief to point 
    source dischargers in the absence of TMDLs through intake credits, 
    variances, and other water quality permitting procedures.
        EPA received numerous comments on the problem posed in controlling 
    mercury in particular. Many commenters stated that since the primary 
    source of mercury is now atmospheric deposition, point sources 
    contribute only a minor portion of the total loading of mercury to the 
    Great Lakes System and further restriction of point source discharges 
    would have no apparent effect in improving water quality. Although EPA 
    believes that there is sufficient flexibility in the Guidance to handle 
    the unique problems posed by mercury (e.g., water quality variances, 
    phased TMDLs, intake credits), EPA is committed to developing a mercury 
    permitting strategy to provide a holistic, comprehensive approach for 
    dealing with this pollutant. EPA will publish this strategy no later 
    than two years following publication of this Guidance.
        There are also many ongoing voluntary and regulatory activities 
    that address nonpoint sources of toxic pollutants to the Great Lakes 
    System, including activities taken under the Clean Air Act Amendments 
    of 1990 (CAAA), the CWA, and State regulatory and voluntary programs. 
    Some of these activities are summarized in the preamble to the proposed 
    Guidance (58 FR 20826-32) and section I.D of the SID.
        In addition to the many ongoing activities, EPA and the Great Lakes 
    States, Tribes, and other federal agencies are pursuing a multi-media 
    program to prevent and to further reduce toxic loadings from all 
    sources of pollution to the Great Lakes System, with an emphasis on 
    nonpoint sources. This second phase of the Great Lakes Water Quality 
    Initiative, called the Great Lakes Toxic Reduction Effort (GLTRE), will 
    build on the open, participative public dialogue established during the 
    development of the final Guidance. Through the GLTRE, the Federal, 
    State, and Tribal agencies intend to coordinate and enhance the 
    effectiveness of ongoing actions and existing tools to prevent and 
    reduce nonpoint source and wet-weather point source contributions of 
    toxic pollutants in the Great Lakes System. A special emphasis will be 
    placed on BCCs identified in the final Guidance.
        A partial list of ongoing actions that are being or could be 
    focused on BCCs includes: implementation of the CAAA to reduce 
    atmospheric deposition of toxics; Resource Conservation and Recovery 
    Act and CERCLA remedial actions to reduce loadings of toxics from 
    [[Page 15372]] hazardous waste sites; increased focus (through the 
    GLTRE) on toxic pollutants emanating from combined sewer overflows and 
    stormwater outfalls; application in the Great Lakes basin of the 
    National Contaminated Sediment Management Strategy; implementation of 
    spill prevention planning practices to minimize this potential source 
    of loadings to the Great Lakes; improved reporting of toxic pollutants 
    under the Toxic Release Inventory; public education on the dangers of 
    mercury and other BCCs; pesticide registration and re-registration 
    processes; development of a ``mass balance'' model for fate and 
    transport of pollutants in the Great Lakes; and, development of a 
    ``virtual elimination strategy.'' These programs will prevent and 
    further reduce mass loadings of pollutants and facilitate equitable 
    division of the costs of any necessary control measures between point 
    and nonpoint sources.
        In addition to the GLTRE, which is basin-wide in scope, a primary 
    vehicle for coordinating Federal and State programs at the local level 
    for meeting water quality standards and restoring beneficial uses for 
    the open waters of the Great Lakes are LaMPS. LaMPs will define media 
    specific program actions to further reduce loadings of toxic 
    substances, assess whether these programs will ensure restoration and 
    attainment of water quality standards and designated beneficial uses, 
    and recommend any media-specific program enhancements as necessary. 
    Additionally, LaMPs will be periodically updated and revised to assess 
    progress in implementing media-specific programs, assess the reductions 
    in toxic loadings to the Great Lakes System through these programs, 
    incorporate advances in the understanding of the System based on new 
    data and information, and recommend specific adjustments to media 
    programs as appropriate.
    
    E. Promote Pollution Prevention Practices
    
        The final Guidance also promotes pollution prevention practices 
    consistent with EPA's National Pollution Prevention Strategy and the 
    Pollution Prevention Action Plan for the Great Lakes. The Pollution 
    Prevention Act of 1990 declares as National policy that reducing the 
    sources of pollution is the preferred approach to environmental 
    protection. When source reductions are not possible, however, 
    recycling, treating and properly disposing of pollutants in an 
    environmentally safe manner complete the hierarchy of management 
    options designed to prevent pollution from entering the environment.
        Consistent with the goals of the Pollution Prevention Act, EPA 
    developed the Great Lakes Pollution Prevention Action Plan (April, 
    1991). The Great Lakes Pollution Prevention Action Plan highlights how 
    EPA, in partnership with the States, will incorporate pollution 
    prevention into actions designed to reduce the use and release of toxic 
    substances in the Great Lakes basin.
        The final Guidance builds upon these two components of the Great 
    Lakes program by promoting the development of pollution prevention 
    analysis and activities in the level of detection, mixing zone, and 
    antidegradation sections of the final Guidance. Also, the decision to 
    provide special provisions for BCCs implements EPA's commitment to 
    pollution prevention by reducing the discharge of these pollutants in 
    the future. This preventive step not only makes good environmental 
    management sense, but is appropriate based on the documented adverse 
    effects that the past and present discharge of these pollutants has 
    produced in the Great Lakes basin.
    
    F. Provide Accurate Assessment of Costs and Benefits
    
        In developing the final Guidance, EPA identified and carefully 
    evaluated the anticipated costs and benefits from implementation of the 
    major provisions. EPA received many comments on the draft cost and 
    benefit studies conducted as part of the proposed Regulatory Impact 
    Analysis (RIA) required by Executive Order 12291, and its successor, 
    Executive Order 12866. Based upon consideration of those comments and 
    further analysis, EPA has revised the RIA. The results of this analysis 
    are summarized in section V of this preamble.
    
    IV. Summary of the Final Guidance
    
        The final Guidance will establish minimum water quality standards, 
    antidegradation policies, and implementation procedures for the waters 
    of the Great Lakes System in the States of Illinois, Indiana, Michigan, 
    Minnesota, New York, Pennsylvania, Ohio and Wisconsin, including waters 
    within the jurisdiction of Indian Tribes. Specifically, the final 
    Guidance specifies numeric criteria for selected pollutants to protect 
    aquatic life, wildlife and human health within the Great Lakes System 
    and provides methodologies to derive numeric criteria for additional 
    pollutants discharged to these waters. The final Guidance also contains 
    minimum procedures to translate the proposed ambient water quality 
    criteria into enforceable controls on discharges of pollutants, and a 
    final antidegradation policy.
        The provisions of the final Guidance are not enforceable 
    requirements until adopted by States or Tribes, or promulgated by EPA 
    for a particular State or Tribe. The Great Lakes States and Tribes must 
    adopt water quality standards, antidegradation policies, and 
    implementation procedures for waters within the Great Lakes System 
    consistent with the (as protective as) final Guidance or be subject to 
    EPA promulgation. Great Lakes Tribes include any Tribe within the Great 
    Lakes basin for which EPA has approved water quality standards under 
    section 303 or has authorized to administer a NPDES program under 
    section 402 of the CWA. No Indian Tribe has been authorized to 
    administer these water programs in the Great Lakes basin as of this 
    time. If a Great Lakes State fails to adopt provisions consistent with 
    the final Guidance within two years of this publication in the Federal 
    Register (that is, by March 23, 1997), EPA will publish a final rule at 
    the end of that time period identifying the provisions of the final 
    Guidance that will apply to waters and discharges within that 
    jurisdiction. Additionally, when an Indian Tribe is authorized to 
    administer the NPDES or water quality standards program in the Great 
    Lakes basin, it will also need to adopt provisions consistent with the 
    final Guidance into their water programs.
        The following sections provide a brief summary of the provisions of 
    the final Guidance. A more complete discussion of the final Guidance, 
    including EPA's analysis of major comments, issues, and a description 
    of specific changes made to the proposed Guidance, are contained in the 
    SID.
        The parenthetical note at the beginning of each section provides 
    references to the primary provisions in the final Guidance being 
    discussed in the section, and to discussions in the SID. The final 
    Guidance is codified as 40 CFR 132, including appendixes A through F. 
    Note that appendix F consists of procedures 1 through 9. For ease of 
    reference, sections in appendix F may be referred to by appending the 
    section designation to the procedure number. For example, section A.1 
    of procedure 1 may be referred to as procedure 1.A.1 of appendix F. 
    [[Page 15373]] 
    
    A. Water Quality Criteria and Methodologies
    
    1. Protection of Aquatic Life
        (Secs. 132.3(a), 132.3(b), 132.4(a)(2); Tables 1 and 2 to part 132; 
    appendix A to part 132; section III, SID)
        The final Guidance contains numeric criteria to protect aquatic 
    life for 15 pollutants, and a two-tiered methodology to derive criteria 
    (Tier I) or values (Tier II) for additional pollutants discharged to 
    the Great Lakes System. Aquatic life criteria are derived to establish 
    ambient concentrations for pollutants, which, if not exceeded in the 
    Great Lakes System, will protect fish, invertebrates, and other aquatic 
    life from adverse effects due to that pollutant. The final Guidance 
    includes both acute and chronic criteria to protect aquatic life from 
    acute and chronic exposures to pollutants.
        Tier I aquatic life criteria for each chemical are based on 
    laboratory toxicity data for a variety of aquatic species (e.g., fish 
    and invertebrates) which are representative of species in the 
    freshwater aquatic environment as a whole. The Guidance also includes a 
    Tier II methodology to be used in the absence of the full set of data 
    needed to meet Tier I data requirements. For pollutants for which Tier 
    I criteria have not been adopted into State or Tribal water quality 
    standards, States must use methodologies consistent with either the 
    Tier I or Tier II methodologies, depending on the data available, in 
    conjunction with whole effluent toxicity requirements in the final 
    Guidance (see section IV.B.5 of this preamble), to implement their 
    existing narrative water quality criteria that prohibit toxic 
    pollutants in toxic amounts in all waters. The Great Lakes States and 
    Tribes are not required to use the Tier II methodology to adopt numeric 
    criteria into their water quality standards.
        Use of the two-tiered final Guidance methodologies in these 
    situations will enable regulatory authorities to translate narrative 
    criteria to derive TMDLs and individual NPDES permit limits on a more 
    uniform basis. EPA and the States determined that there is a need to 
    regulate pollutants more consistently in the Great Lakes System when 
    faced with limited numbers of criteria. Many of the Great Lakes States 
    are already employing procedures similar to the approach in the final 
    Guidance to implement narrative criteria. EPA determined the Tier II 
    approach improves upon existing mechanisms by utilizing all available 
    data.
        The two-tiered methodology allows the application of the final 
    Guidance to all pollutants, except those listed in Table 5 of part 132 
    (see section IV.E of this preamble). The Tier I aquatic life 
    methodology includes data requirements very similar to those used in 
    current guidelines for developing National water quality criteria 
    guidance under section 304(a) of the CWA. For example, both require 
    that acceptable toxicity data for aquatic species in at least eight 
    different families representing differing habitats and taxonomic groups 
    must exist before a Tier I numeric criterion can be derived. The Tier 
    II aquatic life methodology is used to derive Tier II values which can 
    be calculated with fewer toxicity data than Tier I. Tier II values can, 
    in certain instances, be based on toxicity data from a single taxonomic 
    family, provided the data are acceptable. The Tier II methodology 
    generally produces more stringent values than the Tier I methodology, 
    to reflect greater uncertainty in the absence of additional toxicity 
    data. As more data become available, the derived Tier II values tend to 
    become less conservative. That is, they more closely approximate Tier I 
    numeric criteria. EPA and the States believe it is desirable to 
    continue to supplement toxicity data to ultimately derive Tier I 
    numeric criteria.
        One difference from the existing National water quality criteria 
    guidelines is that the final Guidance methodology for aquatic life 
    deletes the provision in the National guidelines to use a Final Residue 
    Value (FRV) in deriving a criterion. The FRV is intended to prevent 
    concentrations of pollutants in commercially or recreationally 
    important aquatic species from affecting the marketability of those 
    species or affecting wildlife that consume them by preventing the 
    exceedance of applicable Food and Drug Administration action levels and 
    concentrations that affect wildlife. The final Guidance provides 
    specific, separate methodologies to protect wildlife and human health 
    (discussed below) which EPA believes will provide more accurate and 
    appropriate levels of protection than the FRVs.
        For pollutants without Tier I criteria but with enough data to 
    derive Tier II values for aquatic life, the proposal would have 
    required permittees to meet permit limits based on both Tier II values 
    and whole effluent toxicity (WET) testing. In response to comments, the 
    final Guidance clarifies that States and Tribes may adopt provisions 
    allowing use of indicator parameter limits consistent with 40 CFR 
    122.44(d)(1)(vi)(C). When deriving limits to meet narrative criteria, 
    States and Tribes have the option of using an indicator parameter 
    limit, including use of a WET limit under appropriate conditions, in 
    lieu of a Tier II-based limit. If use of an indicator parameter is 
    allowed, the State or Tribe must ensure that the indicator parameter 
    will attain the ``applicable water quality standard'' (as described in 
    40 CFR 122.44(d)(1)(vi)(C). The ``applicable water quality standard'' 
    in this instance would be the State's or Tribe's narrative water 
    quality standard that protects aquatic life.
        Finally, the aquatic criteria for metals in the proposed Guidance 
    were expressed as total recoverable concentrations. The final Guidance 
    expresses the criteria for metals in dissolved form because the 
    dissolved metal more closely approximates the bioavailable fraction of 
    metal in the water column than does the total recoverable metal. The 
    dissolved criteria are obtained by multiplying the chronic and/or acute 
    criterion by appropriate conversion factors in Table 1 or 2. This is 
    consistent with many comments on the issue and with the policy on 
    metals detailed in ``Office of Water Policy and Technical Guidance on 
    Interpretation and Implementation of Aquatic Life Metals Criteria'' 
    (October 1, 1993). A document describing the methodology to convert 
    total recoverable metals criteria to dissolved metals criteria was 
    published in the Federal Register on August 30, 1994 (59 FR 44678). If 
    a State or Tribe fails to adopt approvable aquatic life criteria for 
    metals, EPA will promulgate criteria expressed as dissolved 
    concentrations.
        EPA Region 5, in cooperation with EPA Regions 2 and 3 and 
    Headquarters offices, and the Great Lakes States and Tribes, will 
    establish a Great Lakes Initiative (GLI) Clearinghouse to assist States 
    and Tribes in developing numeric Tier I water quality criteria for 
    aquatic life, human health and wildlife and Tier II water quality 
    values for aquatic life and human health. As additional toxicological 
    data and exposure data become available or additional Tier I numeric 
    criteria and Tier II values are calculated by EPA, States, or Tribes, 
    Region 5 will ensure that this information is disseminated to the Great 
    Lakes States and Tribes. EPA believes operation of the GLI 
    Clearinghouse will help ensure consistency during implementation of the 
    final Guidance.
    2. Protection of Human Health
        (Secs. 132.3(c), 132.4(a)(4); Table 3 to part 132; appendix C to 
    part 132; section V of the SID)
        The final Guidance contains numeric human health criteria for 18 
    pollutants, and includes Tier I and Tier II methodologies to derive 
    cancer and [[Page 15374]] non-cancer human health criteria for 
    additional pollutants. The proposed Guidance contained numeric criteria 
    for 20 pollutants, but two pollutants were deleted because they do not 
    meet the more restrictive minimum data requirements for BAFs used in 
    the final Guidance.
        Tier I human health criteria are derived to establish ambient 
    concentrations of chemicals which, if not exceeded in the Great Lakes 
    System, will protect individuals from adverse health impacts from that 
    chemical due to consumption of aquatic organisms and water, including 
    incidental water consumption related to recreational activities in the 
    Great Lakes System. For each chemical, chronic criteria are derived to 
    reflect long-term consumption of food and water from the Great Lakes 
    System. Tier II values are intended to provide a conservative, interim 
    level of protection in the establishment of a permit limit, and are 
    distinguished from the Tier I approach by the amount and quality of 
    data used for derivation.
        The final Guidance differs from current National water quality 
    criteria guidelines when calculating the assumed human exposure through 
    consumption of aquatic organisms. The final Guidance uses BAFs 
    predicted from biota-sediment accumulation factors (BSAFs) in addition 
    to field-measured BAFs, and uses a food chain multiplier (FCM) to 
    account for biomagnification when using measured or predicted 
    bioconcentration factors (BCFs). BAFs are discussed further in section 
    IV.A.4. of this preamble.
        Human health water quality criteria for carcinogens are typically 
    expressed in concentrations associated with a plausible upper bound of 
    increased risk of developing cancer. In practice, the level of cancer 
    risk generally accepted by EPA and the States typically ranges between 
    10-\4\ (one in one thousand) and 10-\6\ (one in one million). 
    In contrast, as discussed in section II above, the cancer risk from 
    ingestion of contaminated fish at current concentrations in the Great 
    Lakes System are as high as 1.2  x  10-\2\ (1.2 in 100). The 
    proposed and final Guidance establishes 10-\5\ (one in one hundred 
    thousand) as the risk level used for deriving criteria and values for 
    individual carcinogens. This is within the range historically used in 
    EPA actions, and approved for State actions, designed to protect human 
    health. The majority of the Great Lakes States use 10-\5\ as a 
    baseline risk level in establishing their water quality standards.
        The methodology is designed to protect humans who drink water or 
    consume fish from the Great Lakes System. The portion of the 
    methodology addressing fish consumption includes a factor describing 
    how much fish humans consume per day. The final Guidance includes a 
    Great Lakes-specific fish consumption rate of 15 grams per day, based 
    upon several fish consumption surveys from the Great Lakes, including a 
    recent study by West et al. that was discussed in a Federal Register 
    document on August 30, 1994 (59 FR 44678). This rate differs from the 
    6.5 grams per day rate which is used in the National water quality 
    criteria guidelines as a National average consumption value. The 15 
    grams per day represents the mean consumption rate of regional fish 
    caught and consumed by the Great Lakes sport fishing population.
        Commenters argued that a 15 gram per day assumption in the 
    methodology would not adequately protect populations that consume 
    greater than this amount (e.g., low-income minority anglers and Native 
    Americans), and that such an approach therefore would be inconsistent 
    with Executive Order 12898 regarding environmental justice (February 
    16, 1994, 59 FR 7629). EPA believes that the human health criteria 
    methodology, including the fish consumption rate, will provide adequate 
    health protection for the public, including more highly exposed sub-
    populations. In carrying out regulatory actions under a variety of 
    statutory authorities, including the CWA, EPA has generally viewed an 
    upper bound incremental cancer risk in the range of 10-4 to 
    10-6 as adequately protective of public health. As discussed 
    above, the human health criteria methodology is based on a risk level 
    of 10-5. Therefore, if fish are contaminated at the level 
    permitted by criteria derived under the final Guidance, individuals 
    eating up to 10 times (i.e., 150 grams per day) the assumed fish 
    consumption rate would still be protected at the 10-4 risk level. 
    Available data indicate that, even among low-income minorities who as a 
    group consume more fish than the population on average, the 
    overwhelming majority (approximately 95 percent) consume less than 150 
    grams per day. The final Guidance requires, moreover, that States and 
    Tribes modify the human health criteria on a site-specific basis to 
    provide additional protection appropriate for highly exposed sub-
    populations. Thus, where a State or Tribe finds that a population of 
    high-end consumers would not be adequately protected by criteria 
    derived using the 15 gram per day assumption (e.g., where the risk was 
    greater than 10-4), the State or Tribe would be required to modify 
    the criteria to provide appropriate additional protection. The final 
    Guidance also requires States and Tribes to adopt provisions to protect 
    human health from the potential adverse effects of mixtures of 
    pollutants in effluents, specifically including mixtures of 
    carcinogens. Understood in the larger context of the human health 
    methodology and the final Guidance as a whole, therefore, EPA believes 
    that the 15 gram per day fish consumption rate provides adequate health 
    protection for the public, including highly exposed populations, and 
    that the final Guidance is therefore consistent with Executive Order 
    12898.
        In developing bioaccumulation factors, the proposed Guidance used a 
    5.0 percent lipid value for fish consumed by humans, based on Great 
    Lakes-specific data. The current National methodology uses a 3.0 
    percent lipid value. The final Guidance uses a 3.10 percent lipid value 
    for trophic level 4 fish and 1.82 for trophic level 3 fish. These 
    percent lipid values are based on an analysis of the West et al. study 
    cited above and data from State fish contaminant monitoring programs.
        The final Guidance contains specific technical guidelines 
    concerning the range of uncertainty factors that may be applied by the 
    State and Tribal agencies on the basis of their best professional 
    judgment. The final Guidance places a cap of 30,000 on the combined 
    product of uncertainty factors that may be applied in the derivation of 
    non-cancer Tier II values and a combined uncertainty factor of 10,000 
    for Tier I criteria. The likely maximum combined uncertainty factor for 
    Tier I criteria in most cases is 3,000. The SID discusses further the 
    use of the uncertainty factors in the derivation of human health 
    criteria and values.
        The proposed Guidance used an 80 percent relative source 
    contribution (RSC) from surface water pathways for BCCs, and a 100 
    percent RSC for all other pollutants, in deriving noncancer criteria. 
    The RSC concept is applied in the National drinking water regulations 
    and is intended to account, at least in part, for exposures from other 
    sources for those bioaccumulative pollutants for which surface water 
    pathways are likely to be major contributors to human exposure. The 
    final Guidance uses the more protective 80 percent RSC for all 
    pollutants in deriving noncancer criteria. This change was made because 
    of concern that for non-BCCs as well as [[Page 15375]] BCCs, there may 
    be other sources of exposures for noncarcinogens.
    3. Protection of Wildlife
        (Secs. 132.3(d), 132.4(a)(5); Table 4 to part 132; appendix D to 
    part 132; section VI of the SID)
        The final Guidance contains numeric criteria to protect wildlife 
    for four pollutants and a methodology to derive Tier I criteria for 
    additional BCCs. Wildlife criteria are derived to establish ambient 
    concentrations of chemicals which, if not exceeded, will protect 
    mammals and birds from adverse impacts from that chemical due to 
    consumption of food and/or water from the Great Lakes System.
        These are EPA's first water quality criteria specifically for the 
    protection of wildlife. The methodology is based largely on the 
    noncancer human health paradigm. It focuses, however, on endpoints 
    related to reproduction and population survival rather than the 
    survival of individual members of a species. The methodology 
    incorporates pollutant-specific effect data for a variety of mammals 
    and birds and species-specific exposure parameters for two mammals and 
    three birds representative of mammals and birds resident in the Great 
    Lakes basin which are likely to experience significant exposure to 
    bioaccumulative contaminants through the aquatic food web.
        In the proposal, EPA included a two-tiered approach similar to that 
    for aquatic life and human health. In response to comments, the final 
    Guidance requires States and Tribes to adopt provisions consistent with 
    only the Tier I wildlife methodology, and only to apply this 
    methodology for BCCs (see section IV.A.4 below). The TSD provides 
    discretionary guidelines for the use of Tier I and Tier II 
    methodologies for other pollutants. The wildlife methodology was 
    limited to the BCCs because these are the chemicals of greatest concern 
    to the higher trophic level wildlife species feeding from the aquatic 
    food web in the Great Lakes basin. This decision is consistent with 
    comments made by the EPA Science Advisory Board (SAB) who agreed that 
    the initial focus for wildlife criteria development should be on 
    persistent, bioaccumulative organic contaminants (USEPA, 1994, EPA-SAB-
    EPEC-ADV-94-001).
        Numerous commenters were concerned that the mercury criterion for 
    wildlife was not scientifically appropriate. After review of all 
    comments and a reevaluation of all the data, the mercury criterion for 
    wildlife has been increased from 180 pg/L to 1300 pg/L. EPA believes 
    the 1300 pg/L is protective of wildlife in the Great Lakes System.
        In developing bioaccumulation factors, the proposed Guidance used a 
    7.9 percent lipid value for fish consumed by wildlife. The final 
    Guidance uses a 10.31 percent lipid value for trophic level 4 fish and 
    6.46 for trophic level 3 fish. These percent lipid values are based on 
    the actual prey species consumed by the representative wildlife species 
    specified in the methodology, and are used to estimate the BAFs for the 
    trophic levels which those species consume. The percent lipid is based 
    on the preferential consumption patterns of wildlife and cross-
    referenced with fish weight and size and appropriate percent lipid. 
    This approach is a more accurate reflection of the lipid content of the 
    fish consumed by wildlife species than the approach used in the 
    proposal.
    4. Bioaccumulation Methodology
    (Sec. 132.4(a)(3); appendix B to part 132; section IV of the SID)
    
        The proposed Guidance incorporated BAFs in the derivation of 
    criteria and values to protect human health and wildlife. 
    Bioaccumulation refers to the uptake and retention of a substance by an 
    aquatic organism from its surrounding medium and from food. For certain 
    chemicals, uptake through the aquatic food chain is the most important 
    route of exposure for wildlife and humans. The wildlife criteria and 
    the human health criteria and values incorporate appropriate BAFs in 
    order to more accurately account for the total exposure to a chemical. 
    Current EPA guidelines for the derivation of human health water quality 
    criteria use BCFs, which measure only uptake from water, when field-
    measured BAFs are not available. EPA believes, however, that the BAF is 
    a better predictor of the concentration of a chemical within fish 
    tissues in the Great Lakes System because it includes consideration of 
    the uptake of contaminants from all routes of exposure.
        The proposed Guidance included a hierarchy of three methods for 
    deriving BAFs for non-polar organic chemicals: field-measured BAFs; 
    predicted BAFs derived by multiplying a laboratory-measured BCF by a 
    food-chain multiplier; and BAFs predicted by multiplying a BCF 
    calculated from the log Kow by a food-chain multiplier. For 
    inorganic chemicals, the proposal would have required either a field-
    measured BAF or laboratory-measured BCF. On August 30, 1994, EPA 
    published a document in the Federal Register (59 FR 44678) requesting 
    comments on revising the hierarchy of methods for deriving BAFs for 
    organic chemicals, and issues pertaining to the model used to assist in 
    predicting BAFs when a field-measured BAF is not available. Based on 
    the comments received, the final Guidance modifies the proposed 
    hierarchy by adding a predicted BAF based on a BSAF as the second 
    method in the hierarchy. BSAFs may be used for predicting BAFs from 
    concentrations of chemicals in surface sediments. In addition, the 
    final Guidance uses a model to assist in predicting BAFs that includes 
    both benthic and pelagic food chains thereby incorporating exposures of 
    organisms to chemicals from both the sediment and the water column. The 
    model used in the proposal only included the pelagic food chain, and 
    therefore, did not account for exposure to aquatic organisms from 
    sediment.
        The proposed Guidance used the total concentration of a chemical in 
    the ambient water when deriving BAFs for organic chemicals. In the 
    preamble to the proposed Guidance and in the Federal Register document 
    cited above, EPA requested comments on deriving BAFs in terms of the 
    freely dissolved concentration of the chemical in the ambient water. 
    Based on comments received from the proposal and the document, the 
    final Guidance uses the freely dissolved concentration of a chemical 
    instead of the total concentration in the derivation of BAFs for 
    organic chemicals. Use of the freely dissolved concentration will 
    improve the accuracy of extrapolations between water bodies.
        Finally, as discussed in section II of this preamble, 
    bioaccumulation of persistent pollutants is a serious environmental 
    threat to the Great Lakes Basin Ecosystem. Because of these concerns, 
    the proposed Guidance would have required that pollutants with human 
    health BAFs greater than 1000 receive increased attention and more 
    stringent controls within the Great Lakes System. These pollutants are 
    termed BCCs. EPA identified 28 BCCs in the proposed Guidance. The 
    additional controls for BCCs are specified in certain of the 
    implementation procedures and the antidegradation procedures, and are 
    discussed further in the SID. The final Guidance continues to include 
    increased attention on and more stringent controls for BCCs within the 
    Great Lakes System. The final Guidance identifies 22 BCCs that are 
    targeted for special controls instead of the 28 in the proposed 
    Guidance. Six BCCs were deleted from the proposed list because of 
    concern that the methods used to estimate the BAFs may not 
    [[Page 15376]] account for the metabolism or degradation of the 
    pollutants in the environment. States and Tribes may identify more BCCs 
    as additional BAF data become available. The final Guidance designates 
    as BCCs only those chemicals with human health BAFs greater than 1000 
    that were derived from either a field-measured BAF or a predicted BAF 
    based on a field-measured BSAF (for non-metals) or from a field-
    measured BAF or a laboratory-measured BCF (for metals). Field-measured 
    BAFs and BSAFs, unlike BAFs based only on laboratory analyses or 
    calculations, account for the effects of metabolism.
    
    B. Implementation Procedures
    
    (Secs. 132.4(a)(7), 132.4(e); appendix F to part 132; section VIII of 
    the SID)
    
        This section of the preamble discusses nine specific procedures 
    contained in the final Guidance for implementing water quality 
    standards and developing NPDES permits to attain the standards.
    1. Site-Specific Modifications
    (Procedure 1 of appendix F to part 132; section VIII.A of the SID)
    
        The proposed Guidance would have allowed States and Tribes to adopt 
    site-specific modifications to water quality criteria and values under 
    certain circumstances. States and Tribes could modify aquatic life 
    criteria to be either more stringent or less stringent when local water 
    quality characteristics altered the biological availability or toxicity 
    of a pollutant, or where local species' sensitivities differed from 
    tested species. Less stringent modifications to chronic aquatic life 
    criteria could also be made to reflect local physical and hydrological 
    conditions. States and Tribes could also modify BAFs and human health 
    and wildlife criteria to be more stringent, but not less stringent than 
    the final Guidance.
        The final Guidance retains most of the above provisions, but in 
    addition allows less stringent modifications to acute aquatic life 
    criteria and values to reflect local physical and hydrological 
    conditions, less stringent modifications to BAFs in developing human 
    health and wildlife criteria, and the use of fish consumption rates 
    lower than 15 grams per day if justified. The final Guidance also 
    specifies that site-specific modifications must be made to prevent 
    water quality that would cause jeopardy to endangered or threatened 
    species that are listed or proposed under the ESA, and prohibits any 
    less-stringent site-specific modifications that would cause such 
    jeopardy. Other issues related to the ESA are discussed in section IX 
    of this preamble.
    2. Variances from Water Quality Standards for Point Sources
    (Procedure 2 of appendix F to part 132; section VIII.B of the SID)
    
        The final Guidance allows Great Lakes States and Tribes to adopt 
    variances from water quality standards, applicable to individual 
    existing Great Lakes dischargers for up to five years, where specified 
    conditions exist. For example, a variance may be granted when 
    compliance with a criterion would result in substantial and widespread 
    social and economic impacts or where certain stream conditions prevent 
    the attainment of the criterion. No significant changes were made in 
    this section from the proposed Guidance.
    3. TMDLs and Mixing Zones
    (Procedure 3 of appendix F to part 132; section VIII.C of the SID)
    
        Section 303(d) of the CWA and implementing regulations at 40 CFR 
    130.7 require the establishment of TMDLs for waters not attaining water 
    quality standards after implementation of existing or planned pollution 
    controls. The TMDL quantifies the maximum allowable loading of a 
    pollutant to a water body and allocates the loading capacity to 
    contributing point and nonpoint sources (including natural background) 
    such that water quality standards for that pollutant will be attained. 
    A TMDL must incorporate a margin of safety (MOS) that accounts for 
    uncertainty about the relationship between pollutant loads and water 
    quality. TMDLs may involve single point sources or multiple sources 
    (e.g., point sources and nonpoint sources) and may be established for 
    geographic areas that range in size from large watersheds to relatively 
    small water body segments.
        The proposal attempted to develop a single, consistent approach for 
    developing TMDLs to be used by all States and Tribes in the Great Lakes 
    System. Current practice in the eight Great Lakes States includes 
    distinct technical procedures and program approaches that differ in 
    scale, emphasis, scope and level of detail. Two options for TMDL 
    development were proposed. One, Option A, focused on first evaluating 
    the basin as a whole and then conducting individual site-by-site 
    adjustments as necessary to ensure attainment of water quality 
    standards at each location in the basin. The other, Option B, focused 
    on evaluating limits needed for individual point sources with 
    supplemental emphasis on basin-wide considerations as necessary. Both 
    approaches are consistent with the CWA, but result in different 
    methodologies for TMDL development.
        Both options proposed that within 10 years of the effective date of 
    the final Guidance (i.e., two five-year NPDES permit terms), mixing 
    zones would be prohibited for BCCs for existing point source discharges 
    to the Great Lakes System. Further, both proposed that mixing zones be 
    denied for new point source discharges of BCCs as of the effective date 
    of the final Guidance. Both options also specified procedures for 
    determining background levels of pollutants present in ambient waters. 
    In addition, the proposal would have tightened the relationship between 
    TMDL development and NPDES permit issuance by providing that TMDLs be 
    established for each pollutant causing an impairment in a water body 
    prior to the issuance or reissuance of any NPDES permits for that 
    pollutant.
        The final Guidance merges both Options A and B into one single set 
    of minimum regulatory requirements for TMDL development. In general, 
    the final TMDL procedures are less detailed than the proposal, and 
    offer more flexibility for States and Tribes in establishing TMDLs. The 
    final TMDL procedures contain elements from both Options A and B that 
    were deemed critical for a minimum level of consistency among the Great 
    Lakes States and Tribes. These critical elements include: mixing zone 
    specifications, design flows, and procedures for determining background 
    concentrations.
        The final Guidance also includes a prohibition on mixing zones for 
    BCCs after 12 years in most circumstances. Maintaining these 
    restrictions on the availability of mixing zones is consistent with 
    both the Steering Committee's policy views and the bi-national GLWQA 
    goal of virtual elimination of persistent, bioaccumulative toxics. 
    Because of the unique nature of the Great Lakes ecosystem, documented 
    ecological impacts, and the need for consistency, EPA believes that the 
    general prohibition on mixing zones for BCCs is reasonable and 
    appropriate. However, a new exception is allowed if a facility with an 
    existing BCC discharge can demonstrate that it is reducing that 
    discharge to the maximum extent feasible (considering technical and 
    economic factors) but cannot meet WQBELs for that discharge without a 
    mixing zone. EPA, in conjunction with stakeholders within the Great 
    Lakes Basin, will develop guidance for use by [[Page 15377]] States and 
    Tribes in exercising the exception provision with special focus on the 
    technical and economic feasibility criteria. This guidance will also 
    consider the notice, public hearing, monitoring and pollution 
    prevention demonstration elements of the exception criteria.
        The final Guidance also retains many of the proposed provisions for 
    calculating background concentrations used in TMDLs and WLAs 
    established in the absence of TMDLs. The procedure addressing data 
    points below the level of detection, however, has been modified so that 
    it no longer specifies the use of default values (i.e., half of the 
    level of detection).
        The final TMDL procedures do not require that TMDLs be established 
    for point sources prior to the issuance/reissuance of NPDES permits. 
    The final Guidance defers to the existing National program for 
    determining when a TMDL is required. Lastly, the final Guidance allows 
    assessment and remediation plans that are approved by EPA under 40 CFR 
    130.6 to be used in lieu of a TMDL for purposes of appendix F as long 
    as they meet the general conditions of a TMDL as outlined by procedure 
    3 of appendix F, and the public participation requirements applicable 
    to TMDLs.
    4. Additivity
    (Procedure 4 of appendix F to part 132; section VIII.D of the SID)
    
        EPA has traditionally developed numeric water quality criteria on a 
    single pollutant basis. While some potential environmental hazards 
    involve significant exposure to only a single compound, most instances 
    of contamination in surface waters involve mixtures of two or more 
    pollutants. The individual pollutants in such mixtures can act or 
    interact in various ways which may affect the magnitude and nature of 
    risks or effects on human health, aquatic life and wildlife. WET tests 
    are available to generally address interactive effects of mixtures on 
    aquatic organisms. EPA's 1986 ``Guidelines for the Health Risk 
    Assessment of Chemical Mixtures'' set forth principles and procedures 
    for human health risk assessment of chemical mixtures. There are 
    currently no technical guidelines on how to assess effects on wildlife 
    from chemical mixtures.
        The preamble for the proposed Guidance discussed several possible 
    approaches to address additive effects from multiple pollutants. 
    Proposed regulatory language was provided for two specific options, 
    each with separate provisions related to aquatic life, wildlife and 
    human health. One approach was developed by the Initiative Committees, 
    modified to delete the application of toxicity equivalency factors 
    (TEFs) for PCBs to wildlife. The other approach was developed by EPA. 
    Neither approach addressed the possible toxicologic interactions 
    between pollutants in a mixture (e.g., synergism or antagonism) because 
    of the limited data available on these interactive effects. In the 
    absence of contrary data, both approaches recommended that the risk to 
    human health from individual carcinogens in a mixture be considered 
    additive, and that a 10-5 risk level be adopted as a cap for the 
    cancer risk associated with mixtures. Both approaches also proposed 
    using TEFs to assess the risk to humans and wildlife from certain 
    chemical classes. The TEF approach converts the concentration of 
    individual components in a mixture of chemicals to an ``equivalent'' 
    concentration expressed in terms of a reference chemical. Both 
    approaches used the 17 TEFs for dioxins and furans identified in the 
    1989 EPA document, ``Estimating Risks Associated with Exposures to 
    Mixtures of Chlorinated Dibenzo-p-Dioxins and -Dibenzofurans,'' and the 
    1989 update.
        The final Guidance includes a general requirement for States and 
    Tribes to adopt an additivity provision consistent with procedure 4 of 
    appendix F to protect human health from the potential additive adverse 
    effects from both the noncarcinogenic and carcinogenic components of 
    chemical mixtures in effluents. The final Guidance also requires the 
    use of the 17 TEFs included in the proposed Guidance to protect human 
    health from the potential additive adverse effects in effluents.
    5. Determining the Need for WQBELs (Reasonable Potential)
    (Procedure 5 of appendix F to part 132; section VIII.E of the SID)
    
        EPA's existing regulations require NPDES permits to include WQBELs 
    to control all pollutants or pollutant parameters which the permitting 
    authority determines are or may be discharged at a level which will 
    cause, have the reasonable potential to cause or contribute to an 
    excursion of any applicable water quality standard. If the permitting 
    authority determines that a discharge has the reasonable potential to 
    cause or contribute to an excursion of an applicable numeric water 
    quality criterion, it must include a WQBEL for the individual pollutant 
    in the permit. In the absence of an adopted numeric water quality 
    criterion for an individual pollutant, the permitting authority must 
    derive appropriate WQBELs from the State or Tribal narrative water 
    quality criterion by either calculating a numeric criterion for the 
    pollutant; applying EPA's water quality criteria developed under 
    section 304(a) of the CWA, supplemented with other information where 
    necessary; or establishing effluent limitations on an indicator 
    pollutant. See 40 CFR 122.44(d)(1).
        The final Guidance implements these National requirements by 
    specifying procedures for determining whether a discharge has the 
    reasonable potential to cause or contribute to an exceedance of Tier I 
    criteria or Tier II values based on facility-specific effluent data. 
    The final Guidance also specifies procedures for determining whether 
    permitting authorities must generate or require permittees to generate 
    data sufficient to calculate Tier II values when specified pollutants 
    of concern in the Great Lakes System are known or suspected of being 
    discharged, but neither Tier I criteria nor Tier II values have been 
    derived due to a lack of toxicological data. EPA believes that the data 
    necessary to calculate Tier II values for aquatic life, wildlife and 
    human health currently exists for most of the specified pollutants of 
    concern.
        The final Guidance maintains all the basic requirements from the 
    proposed procedure. Some minor changes are that the procedure no longer 
    includes a special provision for effluent dominated streams, and the 
    procedure allows a broader range of statistical approaches to be used 
    when evaluating effluent data, which provides added simplicity and 
    flexibility to States and Tribes.
        Another change from the proposal is the relationship in the final 
    Guidance between the reasonable potential and TMDL procedures. Numerous 
    commenters pointed out that the proposed Guidance indicated that TMDLs 
    would be required for any water receiving effluent from a discharger 
    found to exhibit reasonable potential. Given the fact that there are 
    many waterbodies in the Great Lakes basin for which TMDLs have not been 
    developed, and the obvious need for permitting to proceed in the 
    interim until TMDLs are completed, the final Guidance provides that the 
    permitting authority can establish waste load allocations and WQBELs in 
    the absence of a TMDL or an assessment and remediation plan developed 
    and approved in accordance with procedure 3.A of appendix F. A more 
    detailed discussion of the assessment and remediation plan and its 
    relationship to a TMDL can be found in section VIII.C.2 of the SID. 
    Procedures for establishing such WLAs are therefore addressed in the 
    final Guidance. [[Page 15378]] 
    6. Intake Pollutants
    (Procedures 5.D and 5.E of appendix F to part 132; section VIII.E of 
    the SID)
    
        The proposed Guidance allowed a permitting authority to determine 
    that the return of an identified intake water pollutant to the same 
    body of water under specified circumstances does not cause, have the 
    reasonable potential to cause, or contribute to an excursion above 
    water quality standards, and therefore, that a WQBEL would not be 
    required for that pollutant. Under the proposal, this ``pass through'' 
    of intake water pollutants would be allowed if the facility returns the 
    intake water containing the pollutant of concern to the same waterbody; 
    does not contribute additional mass of pollutant; does not increase the 
    concentration of the intake water pollutant; and does not discharge at 
    a time or location, or alter the pollutant in a manner which would 
    cause adverse impacts to occur that would not occur if the pollutant 
    were left in-stream.
        EPA received numerous comments on the proposal. Some commenters 
    argued that the proposed provision was too narrow because relief would 
    not be available if the facility added any amount of the pollutant to 
    the discharge, even where the facility was not contributing any 
    additional mass or concentration to the waterbody than was contained in 
    the intake water. After consideration of public comments, EPA decided 
    to expand the intake pollutant provisions to include not only a 
    reasonable potential procedure like the one contained in the proposal, 
    but also a provision that allows the permitting authority to take into 
    account the presence of pollutants in intake water in deriving WQBELs. 
    Specifically, the final Guidance authorizes the permitting authority to 
    establish limits based on a principle of ``no net addition'' (i.e., the 
    limit would allow the mass and concentration of the pollutant in the 
    discharge up to the mass and concentration of the pollutant in the 
    intake water). This provision would be available where the facility's 
    discharge is to the same body of water as the intake water, and could 
    be applied for up to 12 years after publication of the final Guidance. 
    After that time, if a TMDL or comparable plan that meets the 
    requirements of procedure 3 of appendix F has not been completed, the 
    facility's WQBEL must be established in accordance with the 
    ``baseline'' provisions in procedure 5.F.2 of appendix F. This time 
    limit provides a period of relief for dischargers that are not causing 
    increased impacts on the waterbody by virtue of their discharge that 
    would not have occurred had the pollutant remained in-stream, while 
    maintaining the incentive for development of a comprehensive assessment 
    and remediation plan for achieving attainment of water quality 
    standards, which EPA believes is a critical element of the final 
    Guidance for addressing pollutants for which a large contributor to 
    non-attainment is nonpoint source pollution.
        The final Guidance allows States and Tribes to address intake 
    pollutants in a manner consistent with assessment and remediation plans 
    that have been developed through mechanisms other than TMDLs in order 
    to provide flexibility where such plans comprehensively address the 
    point and non-point sources of non-attainment in a waterbody and the 
    means for attaining compliance with standards.
        EPA believes that 12 years provides sufficient time for States to 
    develop and complete the water quality assessments that would serve as 
    the basis for establishing effluent limits (including ``no net 
    addition'' limits, where appropriate) under procedure 3.A of appendix 
    F. However, EPA also recognizes that unforeseen events could delay 
    State completion of these assessments, and therefore will, at 7 years 
    following promulgation, in consultation with the States, evaluate the 
    progress of the assessments. If this evaluation shows that completion 
    of the assessments may not be accomplished by the 12 year date, EPA 
    will revisit these provisions, and consider proposing extensions if 
    appropriate.
        Under the final Guidance, the permitting authority can permit the 
    discharge of intake pollutants to a different body of water that is in 
    non-attainment provided limitations require the discharge to meet a 
    WQBEL for the pollutant equal to the pollutant's water quality 
    criterion. Because inter-waterbody transfers of pollutants introduce 
    pollutants to the receiving water that would not be present in that 
    waterbody in the absence of the facility's discharge, EPA does not 
    believe that relief for such pollutants comparable to the ``no net 
    addition'' approach would be appropriate. However, to address the 
    concern raised by commenters about facilities with multiple sources of 
    intake water, the permitting authority may use a flow-weighted 
    combination of these approaches when the facility has co-mingled 
    sources of intake water from the same and different bodies of water.
        EPA maintains that the preferred approach to deal with non-
    attainment waters, particularly when multiple sources contribute a 
    pollutant for which the receiving water exceeds the applicable 
    criterion, is development of a TMDL or comparable assessment and 
    remediation plan. The above ``no net addition'' permitting approach 
    provides additional flexibility in situations where a TMDL or 
    comparable plan has not yet been developed. Other existing relief 
    mechanisms include variances to water quality standards, removal of 
    non-existing uses, and site-specific criteria.
    7. WET
    (Procedure 6 of appendix F to part 132; section VIII.F of the SID)
    
        Existing EPA regulations define WET as ``the aggregate toxic effect 
    of an effluent measured directly by a toxicity test.'' These 
    regulations require WET limits to be included in permits in most 
    circumstances in which the WET of a discharge has the reasonable 
    potential to cause or contribute to an in-stream excursion above either 
    a State's numeric criteria for toxicity or narrative criteria for water 
    quality (40 CFR 122.2, 122.44(d)(1)). The regulations allow States and 
    Tribes the flexibility to control for WET with either numeric or 
    narrative criteria. Current technical guidelines recommend that no 
    discharge should exceed 0.3 acute toxic units (TUa = 100/LC50) at the 
    edge of an acute mixing zone and 1.0 chronic toxic units (TUc = 100/
    NOEC, the No Observed Effect Concentration) at the edge of a chronic 
    mixing zone.
        The proposed Guidance would have continued to allow States and 
    Tribes the flexibility to choose to control WET with either numeric or 
    narrative criteria, but specified that no discharge could exceed 1.0 
    TUa at the point of discharge (i.e., no acute mixing zones) and 
    1.0 TUc at the edge of a chronic mixing zone (with some 
    exceptions). In addition, the proposal contained minimum requirements 
    for appropriate test methods to measure WET and for permit conditions, 
    and procedures for determining whether or not limits for WET are 
    necessary.
        The final Guidance differs principally from the proposal in 
    requiring States and Tribes to adopt 0.3 TUa and 1.0 TUc 
    either as numeric criteria or as an equivalent numeric interpretation 
    of narrative criteria. The final Guidance also allows the use of acute 
    mixing zones for the application of the acute criterion. This approach 
    will promote consistency among States and Tribes in controlling WET, 
    while still permitting considerable flexibility regarding 
    implementation measures, consistent with current National policies and 
    guidelines. [[Page 15379]] 
    8. Loading Limits
    (Procedure 9 of appendix F to part 132; section VIII.G of the SID)
    
        The final Guidance provides that WQBELs be expressed in terms of 
    both concentration and mass loading rate, except for those pollutants 
    that cannot appropriately be expressed in terms of mass. These 
    provisions clarify the application of existing Federal regulations at 
    40 CFR 122.45(f), and are consistent with current EPA guidance which 
    requires the inclusion of any limits determined necessary based on best 
    professional judgment to meet water quality standards, including, where 
    appropriate, mass loading rate limits. They are also consistent with 
    the antidegradation policy for the Great Lakes System in appendix E of 
    the final Guidance.
    9. Levels of Quantification
    (Procedure 8 of appendix F to part 132; section VIII.H of the SID)
    
        Many of the pollutants of concern in the Great Lakes System cause 
    unacceptable toxic effects at very low concentrations. This results in 
    instances where WQBELs are below levels of reliable quantification. 
    When this occurs, the permitting authority may not be able to determine 
    whether the pollutant concentration is above or below the WQBEL. The 
    final Guidance requires adoption of pollutant minimization programs 
    (PMPs) for such permits to increase the likelihood that the 
    concentration of the pollutant is as close to the effluent limit as 
    possible. The PMP is an ongoing, iterative process that requires, among 
    other things, internal wastestream monitoring and submission of status 
    reports. The use of PMPs for facilities with pollutants below the level 
    of quantification is consistent with existing EPA guidance.
        Unlike the proposal, however, the final Guidance eliminates 
    additional minimum requirements for BCCs. For example, the final 
    Guidance recommends but does not require bio-uptake studies that had 
    been proposed to assess impacts to the receiving water and evaluate the 
    effectiveness of the PMP.
    10. Compliance Schedules
    (Procedure 9 of appendix F to part 132; section VIII.I of the SID)
    
        The final Guidance includes a procedure that allows Great Lakes 
    States and Tribes to include schedules of compliance in permits for 
    existing Great Lakes dischargers for effluent limitations based on new 
    water quality criteria and certain other requirements. Generally, 
    compliance schedules may provide for up to five years to comply with 
    the effluent limitation in question and may, in specified cases, allow 
    the compliance schedule to go beyond the term of the permit. Existing 
    Great Lakes dischargers are those whose construction commenced before 
    March 23, 1997. Thus the term, existing Great Lakes discharges, covers 
    expanding dischargers who were ineligible for compliance schedules 
    under the proposal. The final Guidance also provides the opportunity 
    for States and Tribes to allow dischargers additional time to comply 
    with effluent limitations based on Tier II values while conducting 
    studies to justify modifications of those limitations.
    
    C. Antidegradation Provisions
    
    (Sec. 132.4(a)(6); appendix E to part 132; section VII of the SID)
    
        EPA's existing regulations, at 40 CFR 131.6, establish an 
    antidegradation policy as one of the minimum requirements of an 
    acceptable water quality standards submittal. Section 131.12 describes 
    the required elements of an antidegradation policy. These are: 
    protection of water quality necessary to maintain existing uses, 
    protection of high quality waters (those where water quality exceeds 
    levels necessary to support propagation of fish, shellfish, and 
    wildlife and recreation in and on the waters) and protection of water 
    quality in those water bodies identified as outstanding National 
    resources.
        The proposed Guidance provided detailed procedures for implementing 
    antidegradation that were not part of the existing regulations. The 
    detailed implementation procedures were intended to result in greater 
    consistency in how antidegradation was applied throughout the Great 
    Lakes System. The proposed Guidance specified, among other things, how 
    high quality waters should be identified, what activities should and 
    should not require review under antidegradation, and the information 
    necessary to support a request to lower water quality and the 
    procedures to be followed by a Tribe or State in making a decision 
    whether or not to allow a lowering of water quality.
        The final Guidance maintains the overall structure of the proposed 
    Guidance while allowing Tribes and States greater flexibility in how 
    antidegradation is implemented. As in the proposal, the final Guidance 
    is composed of an antidegradation standard, antidegradation 
    implementation procedures, antidegradation demonstration and 
    antidegradation decision. However, many of the detailed requirements 
    found in the proposed Guidance appear in the SID accompanying the final 
    Guidance as nonbinding guidelines, including provisions specific to 
    non-BCCs.
        Key elements of the proposed Guidance that are retained in the 
    final Guidance for BCCs include: identification of high quality waters 
    on a pollutant-by-pollutant basis; requirements for States and Tribes 
    to adopt an antidegradation standard consistent with the final Guidance 
    for BCCs; minimum requirements for conducting an antidegradation review 
    of any activity expected to result in a significant lowering of water 
    quality due to BCCs, minimum requirements for notifying permitting 
    authorities of increases in discharges of BCCs; and, minimum 
    requirements for an antidegradation demonstration consisting of a 
    pollution prevention analysis, an alternative treatment analysis and a 
    showing that the significant lowering of water quality will allow for 
    important social and economic development. Significant changes from the 
    proposed Guidance include: encouraging, but not requiring, States and 
    Tribes to adopt provisions consistent with the antidegradation standard 
    and implementation procedures for non-BCCs; replacement of numeric 
    existing effluent quality-based (EEQ) limits as a means of implementing 
    antidegradation for BCCs with a narrative description of the types of 
    activities that will trigger an antidegradation review; and greater 
    flexibility in the implementation, demonstration and decision 
    components. A detailed discussion of the basis for each of the changes 
    is provided in Section VII the SID.
    
    D. Regulatory Requirements
    
    (Part 132; Tables 5 and 6 to part 132; section II of the SID)
    
        The Great Lakes States must adopt water quality standards, anti-
    degradation policies, and implementation procedures for waters within 
    the Great Lakes System which are consistent with the final Guidance 
    within two years of this publication. If a Great Lakes State fails to 
    adopt such standards, policies, and procedures, section 118(c)(2)(C) of 
    the CWA requires EPA to promulgate them not later than the end of that 
    two-year period. Additionally, when an Indian Tribe is authorized to 
    administer the NPDES or water quality standards program in the Great 
    Lakes basin, it will also need to adopt provisions consistent with the 
    final Guidance into its water program.
        Part 132 establishes requirements and procedures to implement 
    section 118(c)(2)(C). Sections 132.3 and 132.4 [[Page 15380]] require 
    Great Lakes States and Tribes to adopt criteria, methodologies, 
    policies, and procedures consistent with the criteria, methodologies, 
    policies, and procedures contained in part 132--that is, the 
    definitions in Sec. 132.2, the numeric criteria in Tables 1 through 4, 
    the criteria development methodologies in appendixes A through D, the 
    antidegradation policy in appendix E, and the implementation procedures 
    in appendix F. Section 132.5 specifies the procedures for States and 
    Tribes to make their submissions to EPA, and for EPA to approve or 
    disapprove the submissions. The section specifies that in reviewing 
    submissions, EPA will consider provisions of State and Tribal 
    submissions to be ``consistent with'' the final Guidance if each 
    provision is as protective as the corresponding provision of the final 
    Guidance. If a State or Tribe fails to make a submission, or if 
    provisions of the submission are not consistent with the final 
    Guidance, Sec. 132.5 provides that EPA will publish a final rule in the 
    Federal Register identifying the final Guidance provisions that will 
    apply to discharges within the particular State or Federal Indian 
    Reservation.
        Section 132.4 specifies that water quality criteria adopted by 
    States and Tribes consistent with the final Guidance will apply to all 
    waters of the Great Lakes System, regardless of designated uses of the 
    waters in most cases, with some variations in human health criteria 
    depending on whether the waters are designated for drinking water use. 
    Section 132.4 also contains certain exceptions in applying the final 
    Guidance methodologies and procedures. First, States and Tribes do not 
    have to adopt and apply the final Guidance methodologies and procedures 
    for the 14 pollutants listed in Table 5 of part 132. EPA believes that 
    some or all of the methodologies and procedures are not scientifically 
    appropriate for these pollutants. Second, if a State or Tribe 
    demonstrates that the final Guidance methodologies or procedures are 
    not scientifically defensible for a particular pollutant, the State or 
    Tribe may use alternate methodologies or procedures so long as they 
    meet all applicable Federal, State, and Tribal laws. Third, Sec. 132.4 
    specifies that for wet-weather point sources, States and Tribes 
    generally do not have to adopt and apply the final Guidance 
    implementation procedures. The exception is the TMDL general condition 
    for wet weather events. Fourth, pursuant to section 510 of the CWA, 
    part 132 specifies that nothing in the final Guidance prohibits States 
    or Tribes from adopting provisions more stringent than the final 
    Guidance.
        As discussed further in section IX of this preamble, Sec. 132.4 
    also provides that State and Tribal submissions will need to include 
    any provisions that EPA determines, based on EPA's authorities under 
    the CWA and the results of consultation with the U.S. Fish and Wildlife 
    Service (FWS) under section 7 of the ESA, are necessary to ensure that 
    water quality is not likely to cause jeopardy to any endangered or 
    threatened species listed under the ESA.
        Part 132 extends the requirements of section 118(c)(2)(C) to Indian 
    Tribes within the Great Lakes basin for which EPA has approved water 
    quality standards under section 303 of the CWA or which EPA has 
    authorized to administer an NPDES program under section 402 of the CWA. 
    EPA believes that inclusion of Great Lakes Tribes in this way is 
    necessary and appropriate to be consistent with section 518 of the CWA. 
    The reasons for EPA's proposal are discussed further in the preamble to 
    the proposed Guidance (58 FR 20834), and section II.D.3 of the SID. As 
    a practical matter, no Great Lakes Tribes currently have approved water 
    quality standards or authorized NPDES programs, so the submission 
    requirements of part 132 do not apply to any Great Lakes Tribes. Tribes 
    that are approved or authorized in the future, however, will need to 
    adopt provisions consistent with the final Guidance in their water 
    programs.
    
    V. Costs, Cost-Effectiveness and Benefits
    
    (Section IX of the SID)
    
        Under Executive Order 12866 (58 FR 51735, October 4, 1993), EPA 
    must determine whether the regulatory action is ``significant'' and 
    therefore subject to Office of Management and Budget (OMB) review and 
    the requirements of the Executive Order. The Order defines 
    ``significant regulatory action'' as one that is likely to result in a 
    rule that may:
        (1) Have an annual effect on the economy of $100 million or more or 
    adversely affect in a material way the economy, a sector of the 
    economy, competition, jobs, the environment, public health or safety, 
    or State, local, or Tribal governments or communities;
        (2) Create a serious inconsistency or otherwise interfere with an 
    action taken or planned by another agency;
        (3) Materially alter the budgetary impact of entitlements, grants, 
    user fees, or loan programs or the rights and obligations of recipients 
    thereof; or
        (4) Raise novel legal or policy issues arising out of legal 
    mandates, the President's priorities, or the principles set forth in 
    the Executive Order.
        Pursuant to the terms of Executive Order 12866, it has been 
    determined that this rule is a ``significant regulatory action'' 
    because it raises novel policy issues arising out of the development of 
    a comprehensive ecosystem-based approach for a large geographic area 
    involving several States, Tribal governments, local governments, and a 
    large number of regulated dischargers. This approach, including the 
    Great Lakes Water Quality Initiative which developed the core concepts 
    of the final Guidance, is a unique and precedential approach to the 
    implementation of environmental programs. As such, this action was 
    submitted to OMB for review pursuant to Executive Order 12866. Changes 
    made in response to OMB suggestions or recommendations will be 
    documented in the public record.
        The following is a summary of major elements of the ``Regulatory 
    Impact Analysis of the Final Great Lakes Water Quality Guidance'' (RIA) 
    (EPA 820-B-95-011) that has been prepared in compliance with Executive 
    Order 12866. Further discussion is included in section IX of the SID, 
    and in the full RIA, which is available in the docket for this 
    rulemaking.
        The provisions of the final Guidance are not enforceable 
    requirements until adopted by States or Tribes, or promulgated by EPA 
    for a particular State or Tribe. Therefore, this publication of the 
    final Guidance does not have an immediate effect on dischargers. Until 
    actions are taken to promulgate and implement these provisions (or 
    equally protective provisions consistent with the final Guidance), 
    there will be no economic effect on any dischargers. For the purposes 
    of the RIA, EPA's analysis of costs and benefits assumes that either 
    State or EPA promulgations occur consistent with the final Guidance 
    within the next two years.
        Under the CWA, costs cannot be a basis for adopting water quality 
    criteria that will not be protective of designated uses. If a range of 
    scientifically defensible criteria that are protective can be 
    identified, however, costs may be considered in selecting a particular 
    criterion within that range. Costs may also be relevant under the 
    antidegradation standard as applied to high quality waters.
        EPA has assessed compliance costs for facilities that could be 
    affected by provisions adopted by States or Tribes consistent with the 
    final Guidance. EPA has also assessed basin-wide risk reduction 
    benefits to sport anglers and Native American subsistence anglers in 
    the basin, and benefits for three case study sites in the Great Lakes 
    System. [[Page 15381]] The methodology used in each assessment and the 
    results of these assessments are discussed below.
        EPA solicited public comment and supporting data on the RIA 
    methodology used to estimate both costs and benefits for implementation 
    of the proposed Guidance. EPA evaluated these comments and supporting 
    data as well as comments provided by OMB and revised the RIA 
    methodology prior to performing these assessments for the final 
    Guidance.
    
    A. Costs
    
        Based on the information provided by each State and a review of the 
    permit files, EPA identified about 3,800 direct dischargers that could 
    be affected by State or Tribal adoption or subsequent EPA promulgation, 
    if necessary, of requirements consistent with the final Guidance. Of 
    these, about 590 are major dischargers and the remaining 3,210 are 
    minor dischargers. Of the 590 majors, about 275 are industrial 
    facilities and 315 are publicly owned treatment works (POTWs). Out of 
    these dischargers, EPA used a stratified random sampling procedure to 
    select 59 facilities (50 major and nine minor) that it considered 
    representative of all types and sizes of facilities in the basin.
        EPA divided the major facilities into nine industrial categories 
    and a category for POTWs. The nine industrial categories are: mining, 
    food and food products, pulp and paper, inorganic chemical 
    manufacturing, organic chemical manufacturing/petroleum refining, 
    metals manufacturing, electroplating/metal fabrication, steam electric 
    power plants, and miscellaneous facilities.
        For each major and minor facility in the sample, EPA estimated 
    incremental costs to comply with subsequently promulgated provisions 
    consistent with the final Guidance, using a baseline of compliance with 
    the requirements of section 303(c)(2)(B) of the CWA. Using a decision 
    matrix, costs were developed for two different scenarios--a ``low-end'' 
    cost scenario and a ``high-end'' cost scenario--to account for the 
    range of regulatory flexibility available to States and Tribes when 
    adopting and implementing provisions consistent with the final 
    Guidance. In addition, the decision matrix specified assumptions used 
    for selection of control options in the cost analysis such as 
    optimization of existing treatment processes and operations, in-plant 
    pollutant minimization and prevention, and ``end of pipe'' effluent 
    treatment.
        The annualized costs for direct and indirect dischargers to 
    implement the final Guidance are estimated to be between $60 million 
    (low end) and $380 million (high end) (first quarter 1994 dollars). EPA 
    believes the costs for implementing the final Guidance, which balance 
    pollution prevention, ``end-of-pipe'' treatment and regulatory 
    flexibility, will approach the low end of the cost range. Costs are 
    unlikely to reach the high end of the cost range because State and 
    Tribal authorities are likely to choose implementation options that 
    provide some degree of relief to point source dischargers, especially 
    because in many cases the nonpoint source contributions will be 
    significant. Furthermore, cost estimates for both scenarios, but 
    especially for the high-end scenario, may be overstated because in 
    cases where the final Guidance provides States and Tribes flexibility 
    in selecting less costly approaches when implementing provisions 
    consistent with the final Guidance, the most costly approach was used 
    to estimate the costs. This approach was used to reduce uncertainty in 
    the cost analysis for the final Guidance.
        Under the low-end cost scenario, major industrial facilities and 
    POTWs would account for about 65 percent of the costs, indirect 
    dischargers about 33 percent, and minor dischargers about two percent. 
    Among the major dischargers three categories would account for most of 
    the costs--POTWs (39 percent), pulp and paper (14 percent), and 
    miscellaneous (eight percent). The average per plant costs for 
    different industry categories range from zero to $168,000. The two 
    highest average cost categories are pulp and paper ($151,000) and 
    miscellaneous ($168,000). Although major POTWs make up a large portion 
    of the total cost, the average cost per plant under the low-end 
    scenario is not among the highest at $75,000 per facility. About half 
    of the low-end costs are associated with pollution prevention 
    activities, and about half are for capital and operating costs for 
    wastewater treatment.
        For the high-end cost scenario, direct dischargers account for 98 
    percent of the total estimated cost, and indirect dischargers account 
    for two percent. This shift in proportion of costs between direct and 
    indirect dischargers and between the low and the high estimates are due 
    to the assumption that more direct dischargers will need to use end-of-
    pipe treatment under the high-end scenario. In addition, it was assumed 
    that a smaller proportion of indirect dischargers (10 percent) would be 
    impacted under the high-end scenario, since municipalities are adding 
    end-of-pipe treatment which should reduce the need for source controls 
    (i.e., reduce the need for increased pretreatment program efforts) by 
    indirect discharges. Less than 10 percent of the high-end costs are 
    associated with pollution prevention activities, and over 90 percent 
    are for capital and operating costs for wastewater treatment.
        Under the high-end scenario for the direct dischargers, municipal 
    major dischargers are expected to incur just under 70 percent of total 
    costs, and industrial major dischargers account for 29 percent of total 
    costs. Minor direct dischargers are estimated to incur less than one 
    percent of the total costs. The two major industrial categories with 
    the largest total annualized cost are the pulp and paper (23 percent of 
    total) and miscellaneous (three percent) categories. The food and food 
    products and metal finishing categories are estimated to incur less 
    than 1 percent of the total annualized cost.
        Under the high-end scenario, the average annual cost per major 
    municipal facility is just over $822,000 per facility. Average 
    annualized costs for industrial majors vary widely across categories, 
    with the highest average cost estimated for pulp and paper ($1,583,000 
    per plant) and miscellaneous ($433,700 per plant) categories. 
    Regardless of the scenario, the average costs for minor facilities are 
    negligible at an estimated $500 per facility.
        The costs described above account for the costs of eliminating 
    mixing zones for BCCs except in narrow circumstances, costs related to 
    implementation of Tier II values, and specific calculated costs related 
    to intake credits. The cost assessment also projects the potential cost 
    savings across the different scenarios that facilities may realize if 
    States or Tribes use existing regulatory relief mechanisms to modify or 
    eliminate the need for a WQBEL for an identified pollutant (e.g., 
    variances, TMDLs, site-specific modifications to criteria, and changes 
    in designated uses).
        In addition to the cost estimates described above, EPA estimated 
    the cost to comply with requirements consistent with the 
    antidegradation provisions of the final Guidance. This potential future 
    cost is expressed as a ``lost opportunity'' cost for facilities 
    impacted by the antidegradation requirements. This cost could result in 
    the addition of about $22 million each year.
    
    B. Cost-Effectiveness
    
        EPA estimated the cost-effectiveness of the final Guidance in terms 
    of the cost of reducing the loadings of toxic pollutants from point 
    sources. The cost-effectiveness (cost per pound removed) is derived by 
    dividing the annualized costs of implementing the final 
    [[Page 15382]] Guidance by the toxicity-weighted pounds (pound-
    equivalents) of pollutants removed. Pound-equivalents are calculated by 
    multiplying pounds of each pollutant removed by the toxic weight (based 
    on the toxicity of copper) for that pollutant.
        It is estimated that implementation of provisions consistent with 
    the final Guidance would be responsible for the reduction of about six 
    to eight million toxic pounds per year, or 16 to 22 percent of the 
    toxic-weighted baseline for the low- and high-end scenarios, 
    respectively. The cost-effectiveness of the scenarios, over the 
    baseline, is quite good, ranging from $10 to $50 per pound-equivalent.
        Approximately 80 percent of the pollutant load reduction from 
    implementation of the final Guidance, regardless of the scenario, is 
    attributable to reducing BCCs as a result of PMPs and end-of-pipe 
    treatment. The largest pollutant load reductions occur for chlordane, 
    dieldrin, heptachlor, lead, and pentachlorobenzene.
        In a separate analysis, EPA also investigated the cost-
    effectiveness of regulating point and nonpoint sources of mercury and 
    PCBs, two contaminants associated with fish advisories in the Great 
    Lakes basin. Although data and resource constraints limited the 
    findings from these analyses, the preliminary results indicate that 
    point sources may factor cost-effectively into pollutant reduction 
    scenarios. For both contaminants, the cost-effectiveness of point and 
    nonpoint source controls are likely to be highly site-specific.
    
    C. Benefits
    
        The benefits analysis is intended to provide insight into both the 
    types and potential magnitude of the economic benefits expected to 
    arise as a result of implementation of provisions adopted by States and 
    Tribes consistent with the final Guidance. To the extent feasible, 
    empirical estimates of the potential magnitude of the benefits are 
    developed and then compared to the estimated costs of implementing 
    provisions adopted by States and Tribes consistent with the final 
    Guidance.
        The benefits analysis is based on a case study approach, using 
    benefits transfer applied to three case studies. The case study 
    approach was used because it is more amenable to meaningful benefit-
    cost analyses than are studies of larger aggregate areas. Although the 
    results obtained for a case study site may not apply uniformly to the 
    entire Great Lakes basin, the case study approach does provide a 
    pragmatic and realistic perspective of how implementation of the final 
    Guidance can generate benefits, the types of benefits anticipated, and 
    how these benefits compare to costs.
        The case studies include: (1) the lower Fox River drainage, 
    including Green Bay, located on Lake Michigan in northeastern 
    Wisconsin; (2) the Saginaw River and Saginaw Bay, located on Lake Huron 
    in northeastern Michigan; and (3) the Black River, located on Lake Erie 
    in north-central Ohio. The case studies were selected from a list of 
    candidate sites (i.e., designated Areas of Concern (AOCs) in the Great 
    Lakes basin) on the basis of data availability and the relevance of the 
    water quality problems to the final Guidance (i.e., areas in which 
    problems were more likely to be associated with on-going point source 
    discharges rather than historic loadings from Superfund sites and other 
    sources). Geographic diversity was also considered in selecting the 
    sites so that the analyses might better promote a broad perspective of 
    the final Guidance's benefits and costs.
        For each of the three case studies, EPA estimated future toxics-
    oriented water quality benefits, and then attributed a percentage of 
    these benefits to implementation of the final Guidance. The attribution 
    of benefits was based only on the estimated reduction in loadings from 
    point sources at the case study sites and information on the relative 
    contribution of point sources to total loadings in the basin. EPA did 
    not attempt to calculate the longer-term benefits to human health, 
    wildlife, and aquatic life once the final Guidance provisions are fully 
    implemented by nonpoint sources as well as point sources and the 
    minimum protection levels are attained in the ambient water.
        In the Fox River and Green Bay case study, total annual 
    undiscounted benefits attributable to the final Guidance range from 
    $0.3 million to $8.5 million (first quarter 1994 dollars). Human health 
    benefits account for between 29 percent and 72 percent of the estimated 
    benefits, recreational fishing accounts for between eight percent and 
    45 percent, and nonuse/ecologic benefits account for between nine 
    percent and 23 percent. Municipal and industrial dischargers in this 
    case study are estimated to incur annualized costs of about $3.6 
    million.
        In the Saginaw River/Bay case study, total annual undiscounted 
    benefits range from $0.2 million to $7.7 million. Recreational fishing 
    benefits account for between 36 percent and 60 percent of the estimated 
    benefits, non-use benefits account for between 18 percent and 30 
    percent, and human health benefits account for between eight percent 
    and 36 percent. Total annualized costs to municipal and industrial 
    dischargers are estimated to be about $2.6 million.
        In the Black River case study, total annual undiscounted benefits 
    range from $0.4 million to $1.5 million. Recreational fishing benefits 
    account for between 48 percent and 63 percent of the estimated 
    benefits, and nonuse benefits account for between 32 percent and 44 
    percent. Total annualized costs to municipal and industrial dischargers 
    are estimated to be $2.1 million.
        An inherent limitation of the case study approach is the inability 
    to extrapolate from a limited set of river-based sites to the Great 
    Lakes basin as a whole. Accordingly, extrapolation of the case study 
    results to the Great Lakes basin is not recommended. However, as noted 
    above, the three case studies were selected on the basis of data 
    availability, the relative importance of point source discharges to the 
    watersheds' problems, and an attempt to portray spatial diversity 
    throughout the Great Lakes basin. Thus, there is no reason to conclude 
    that the selected sites are not reflective of the basin, even though 
    benefits (and costs) tend to be highly site-specific. In addition, the 
    benefits extend from the case study rivers into the larger, open-water 
    environment of the Great Lakes.
        The representativeness of the case study sites was assessed by 
    comparing the percentage of total benefits estimated to accrue in the 
    case study areas to the percentage of basin-wide costs incurred by the 
    case study sites. Benefits-related measures (such as population, 
    recreational angling days, and nonconsumptive recreation days) were 
    used in place of total benefits for this analysis because there is no 
    estimate of benefits for the entire Great Lakes basin. The three case 
    studies combine to account for nearly 14 percent of the total cost of 
    the final Guidance, nearly 17 percent of the loadings reductions, and 
    from four percent to 10 percent of the benefits proxies (i.e., basin-
    wide population, recreational angling, nonconsumptive recreation, and 
    commercial fishery harvest). Thus, the three case studies may represent 
    a reasonably proportionate share of costs and benefits.
        In addition to the case study analyses, a basin-wide risk 
    assessment was conducted for Great Lakes anglers. EPA collected data 
    and information on the consumption of Great Lakes basin fish to 
    estimate baseline risk levels and reductions in risks due to 
    implementation of the final Guidance for two populations at risk: Great 
    Lakes sport anglers (including minority and [[Page 15383]] low-income 
    anglers) and Native Americans engaged in subsistence fishing in the 
    basin. For sport anglers, EPA estimated that the projected reduction in 
    loadings from point sources based on controls consistent with the final 
    Guidance would result in a reduction of annual excess lifetime cancer 
    cases (potential cancer cases assuming a 70-year lifetime exposure 
    period) of 2.2 to 4.1 for low-income minorities in lakeshore counties; 
    0.4 to 0.8 for other minorities in lakeshore counties; and 21.9 to 41.9 
    for all other sport anglers. For Native American subsistence anglers, 
    EPA estimated that reductions from point source loadings attributable 
    to the final Guidance would result in a reduction of excess lifetime 
    cancer cases of between 0.1 and 0.3 using a low fish ingestion scenario 
    and 0.5 to 1.1 using a high fish ingestion scenario. Note that these 
    estimates do not include the long-term benefits (including reduced 
    cancer cases) that will result once the final Guidance provisions are 
    fully implemented and the minimum protection levels are attained in the 
    ambient water.
        In total, using the most conservative consumption scenario for 
    Native Americans, these reductions represent between 0.35 and 0.67 
    excess cancer cases per year, and potential basin-wide benefits of the 
    final Guidance for this one benefits category of between $0.7 million 
    and $6.7 million per year, based on the estimated value of a 
    statistical life of between $2.0 million and $10.0 million. Comparison 
    to case study results, which were based on a more comprehensive sample 
    of facilities within case study areas than was possible for the entire 
    basin, indicates these values likely underestimate the potential risk 
    reduction benefits of the final Guidance at the basin level. For 
    example, if the average percentage load reduction for PCBs for the 
    three case studies is used to reflect reductions in PCBs for the basin, 
    the reduction in excess cancer cases increases to between three and six 
    cases per year, and potential benefits increase to between $6.6 and $60 
    million per year.
        The reduction in pollutant loadings for PCBs was likely understated 
    in the basin-wide analysis because the analysis did not count pollutant 
    load reduction benefits when the current State-based permit limit and 
    the final Guidance-based permit limit were both below the pollutant 
    analytical method detection limit (MDL). Only three sample facilities 
    in the population of 59 sample facilities used to project basin-wide 
    costs and human health benefits had State-based permit limits for PCBs. 
    Since the current State-based permit limit and the final Guidance-based 
    permit limit were below the MDL in all three facilities, ``zero'' 
    reduction in PCB loadings for the basin was estimated. This, of course, 
    is an artifact of the methodology and the size of the sample population 
    selected for the analysis, and would not occur, as demonstrated in the 
    case study analysis, if a larger sample population had been used.
    
    VI. Regulatory Flexibility Act
    
        Under the Regulatory Flexibility Act (RFA), EPA generally is 
    required to conduct a final regulatory flexibility analysis (FRFA) 
    describing the impact of the regulatory action on small entities as 
    part of the final rulemaking. However, under section 605(b) of the RFA, 
    if EPA certifies that the rule will not have a significant economic 
    impact on a substantial number of small entities, EPA is not required 
    to prepare a FRFA.
        Implementation of the final Guidance is dependent upon future 
    promulgation of provisions consistent with it by State or Tribal 
    agencies or, if necessary, EPA. Until actions are taken to promulgate 
    and implement these provisions, or equally protective provisions 
    consistent with the final Guidance, there will be no economic effect of 
    this rule on any entities, large or small. For that reason, and 
    pursuant to Section 605(b) of the RFA, EPA is certifying that this rule 
    itself will not have a significant economic impact on a substantial 
    number of small entities.
        Although EPA is certifying that this rule will not have a 
    significant economic impact on a substantial number of small entities, 
    and therefore is not required to prepare a FRFA, it is nevertheless 
    including for public information in the RIA a discussion of the 
    possible economic effects to small entities that could result from 
    State or Tribal adoption of provisions consistent with the final 
    Guidance or subsequent EPA promulgation, if necessary. As discussed 
    above, small facilities are projected to incur costs of only 
    approximately $500 per facility to comply with subsequently promulgated 
    requirements that are consistent with the final Guidance. Accordingly, 
    EPA believes there will be no significant economic impact on a 
    substantial number of small entities as a result of State or Tribal 
    implementation of the final Guidance.
    
    VII. Enhancing the Intergovernmental Partnership Under Executive 
    Order 12875
    
        In compliance with Executive Order 12875 (58 FR 58093, October 28, 
    1993), EPA has involved State, Tribal, and local governments in the 
    development of the final Guidance.
        As described in section II above, the core elements of the final 
    Guidance were developed by the Great Lakes States, EPA, and other 
    Federal agencies in open dialogue with citizens, local governments, and 
    industries in the Great Lakes ecosystem over a five-year period through 
    the Initiative. The Initiative process marks the first time that EPA 
    has developed a major rulemaking effort in the water program through a 
    regional public forum. The Initiative process is described further in 
    the preamble to the proposed Guidance (58 FR 20820-23) and section II 
    of this preamble.
        In addition to the participation by State and local governments in 
    the initial development of the proposed Guidance and in the public 
    comment process, several activities have been carried out since the 
    publication of the proposed Guidance. These include:
        (1) On April 26, 1994, EPA held a public meeting to solicit 
    additional information from interested parties on the proposed 
    Guidance. As part of EPA's outreach efforts to State, Tribal and local 
    governments, a special invitation was sent inviting elected officials 
    and other State, Tribal and local representatives to participate in the 
    public meeting. EPA specifically welcomed Tribal and local officials 
    and opened the floor to them to hear and discuss their specific 
    concerns and views on the final Guidance.
        (2) A series of meetings and teleconferences were held with Great 
    Lakes States in early 1994 to discuss their comments on several issues, 
    including development of water quality criteria, State adoption 
    requirements, WET, BAFs, additivity, compliance schedules, anti-
    backsliding, nonpoint sources, and international concerns.
        (3) In October, 1994, EPA met with each individual State in the 
    Great Lakes basin to discuss the nature, form, and scope of the 
    proposed Guidance, and State concerns with implementation of the 
    provisions under consideration. The following issues were discussed at 
    each of the meetings: intake credits, antidegradation and EEQ, wildlife 
    criteria, excluded pollutants (e.g., ammonia and chlorine), elimination 
    of mixing zones, site-specific modifications, fish consumption, 
    appropriate degrees of flexibility for implementation (e.g., guidance 
    vs. regulation), and implementation procedures.
        (4) In 1994 and 1995, EPA met with representatives of the National 
    Wildlife Federation to discuss EPA's activities in developing the final 
    Guidance in [[Page 15384]] accordance with the terms of a consent 
    decree governing the schedule for development of the final Guidance.
        (5) In 1994, EPA also met with elected officials and other 
    representatives from several local communities in the Great Lakes basin 
    to discuss issues regarding the economic impact of the proposed 
    Guidance on local communities and POTWs. Issues discussed include cost 
    impacts associated with implementing water quality criteria, 
    methodologies, and implementation procedures; dealing with pollution 
    from nonpoint sources; public outreach to control pollutants such as 
    mercury instead of costly end-of-pipe treatment; and applicability of 
    provisions in the final Guidance to the National water quality program.
        (6) EPA held an additional 18 consultations with the regulated 
    community throughout 1994. Such meetings allowed representatives of 
    dischargers to share additional data, which has been placed in the 
    docket for this rulemaking, and concerns about a range of issues, 
    including cost concerns, that the dischargers expect to arise in 
    implementation of the final Guidance.
        (7) In 1994, EPA met with State representatives to conduct initial 
    planning for implementation of the GLI Clearinghouse. All Great Lakes 
    States agreed to participate in this effort, which will involve the 
    sharing of toxicological and other data to assist in the development of 
    additional water quality criteria and values.
        The results of the above efforts have assisted in the development 
    of the final Guidance through broad communication with a full range of 
    interested parties, sharing of additional information, and 
    incorporation of features to improve the implementation of the final 
    Guidance.
        EPA has estimated the total annual State government burden to 
    implement the final Guidance as approximately 5,886 hours, resulting in 
    a State government cost of $175,992 annually. Such burden and costs 
    were estimated based upon the burden and costs associated with 
    developing water quality criteria, review of antidegradation policy 
    demonstrations, review of approvable control strategies and BCC 
    monitoring data, and review of variance requests. The total annual 
    local government burden is estimated to be 42,296 hours with an 
    associated cost of $2,008,624. All of the burden and costs to local 
    governments are associated with being a regulated entity as an operator 
    of a POTW.
    
    VIII. Paperwork Reduction Act
    
        The information collection requirements in this final Guidance have 
    been approved by OMB under the Paperwork Reduction Act, 44 U.S.C. 3501 
    et seq., and have been assigned OMB control number 2040-0180. EPA has 
    prepared an Information Collection Request (ICR) document (ICR No. 
    1639.02). A copy of ICR 1639.02 may be obtained by writing to Ms. Sandy 
    Farmer, Information Policy Branch, EPA 2136, Washington, D.C. 20460, or 
    by calling (202) 260-2740.
        The annual public reporting and record keeping burden for this 
    regulation is estimated to be 128,787 hours for the affected 3,795 
    permittees, or an average of 34 hours. This includes the total annual 
    burden to local governments as POTW operators, estimated to be 45,296 
    hours. The total annual burden to State governments is estimated to be 
    5,886 hours. These estimates include time for reviewing instructions, 
    searching existing data sources, gathering and maintaining the data 
    needed, and completing and reviewing the collection of information.
        Send comments regarding the burden estimate or any other aspect of 
    this collection of information, including suggestions for reducing this 
    burden to Chief, Information Policy Branch, Mail Code 2136, U.S. 
    Environmental Protection Agency, 401 M St., S.W., Washington, DC 20460; 
    and to the Office of Information and Regulatory Affairs, Office of 
    Management and Budget, Washington, DC 20503.
        In this rulemaking EPA is also amending the table of currently 
    approved ICR control numbers issued by OMB for various regulations into 
    40 CFR 9.1. This amendment updates the table to accurately display 
    those information requirements promulgated under the CWA. The affected 
    regulations are codified at 40 CFR parts 122, 123, 131, and 132. EPA 
    will continue to present OMB control numbers in a consolidated table 
    format. The table will be codified in 40 CFR part 9 of EPA's 
    regulations and in each 40 CFR volume containing EPA regulations. The 
    table lists the section numbers with reporting and recordkeeping 
    requirements, and the current OMB control numbers. This display of the 
    OMB control numbers and their subsequent codification in the CFR 
    satisfies the requirements of the Paperwork Reduction Act (44 U.S.C. 
    3501 et seq.) and OMB's implementing regulations at 5 CFR part 1320.
        The ICR for this rulemaking was previously subject to public notice 
    and comment prior to OMB approval. As a result, EPA finds that there is 
    ``good cause'' under section 553(b)(B) of the Administrative Procedure 
    Act (5 U.S.C. 553(b)(B)) to amend this table without prior notice and 
    comment. Due to the technical nature of the table, further notice and 
    comment would be unnecessary.
    
    IX. Endangered Species Act
    
        Pursuant to section 7(a)(2) of the ESA, EPA consulted with the FWS 
    concerning EPA's publication of the final Guidance. EPA and the FWS 
    have now completed both informal and formal consultation conducted over 
    a two-year period.
        As a result of the consultation, as well as an analysis of 
    comments, EPA modified several provisions of the final Guidance. The 
    procedure for site-specific modifications provides that Great Lakes 
    States and Tribes must make site-specific modifications to criteria and 
    values where necessary to ensure the resulting water quality does not 
    cause jeopardy to listed or proposed species. Similarly, the 
    antidegradation policy and implementation procedures restrict certain 
    actions States and Tribes may take to allow lowering of water quality 
    in high quality waters, or to adopt variances or mixing zones. 
    Additionally, the regulatory requirements were modified to require 
    Great Lakes States and Tribes to include in their part 132 submissions 
    any provisions that EPA determines, based on EPA's authorities under 
    the CWA and the results of consultation under section 7 of the ESA, are 
    necessary to ensure that water quality is not likely to cause jeopardy 
    to listed species. EPA and the FWS also agreed on how further 
    consultations will be conducted as the final Guidance is implemented. 
    The two agencies also agreed that EPA will undertake a review of water 
    quality standards and implementation of those standards for ammonia and 
    chlorine in the Great Lakes basin as part of EPA's responsibilities 
    under section 303(c) of the CWA.
        During the consultation, two issues were identified that required 
    formal consultation, as defined in 40 CFR part 402. These issues were: 
    the absence of toxicological data concerning effects of contaminants on 
    three species of freshwater mussels in the Great Lakes basin, and the 
    adequacy of the wildlife criteria methodology to protect three 
    endangered or threatened wildlife species in the basin. On February 21, 
    1995, the FWS provided EPA with a written Biological Opinion (Opinion) 
    on these issues. The Opinion is available in the docket for this 
    rulemaking. On both issues, the FWS concluded that the water quality 
    resulting from implementation of the final Guidance will not cause 
    jeopardy to the listed species. To minimize the amount or extent of any 
    incidental take that might [[Page 15385]] occur, the FWS consulted 
    closely with EPA to develop a coordinated approach. The final Opinion 
    specified reasonable and prudent measures that the FWS considers 
    necessary or appropriate to minimize such impact. EPA has agreed to 
    implement the measures, and the FWS and EPA will continue to work 
    cooperatively during the implementation.
    
    X. Judicial Review of Provisions Not Amended
    
        In some situations, EPA has renumbered or included other editorial 
    changes to regulations that have been promulgated in past rulemakings. 
    Additionally, to provide for ease in reading changes to existing 
    regulations, EPA has in some cases repeated entire sections, including 
    portions not changed. The promulgation of this final rule, however, 
    does not provide another opportunity to seek judicial review on the 
    substance of the existing regulations.
    
    XI. Supporting Documents
    
        All documents that are referenced in this preamble are available 
    for inspection and photocopying in the docket for this rulemaking at 
    the address listed at the beginning of this preamble. A reasonable fee 
    will be charged for photocopies.
        Selected documents supporting the final Guidance are also available 
    for viewing by the public at locations listed below:
        Illinois: Illinois State Library, 300 South 2nd Street, 
    Springfield, IL 62701 (217-785-5600)
        Indiana: Indiana Department of Environmental Management, Office of 
    Water Management, 100 North Senate Street, Indianapolis, IN 46204 (317-
    232-8671)
        Michigan: Library of Michigan, Government Documents Service, 717 
    West Allegan, Lansing, MI 48909 (517-373-1300); Detroit Public Library, 
    Sociology and Economics Department, 5201 Woodward Avenue, Detroit, MI 
    48902 (313-833-1440)
        Minnesota: Minnesota Pollution Control Agency, Library, 520 
    Lafayette, St. Paul, MN (612-296-7719)
        New York: U.S. EPA Region 2 Library, Room 402, 26 Federal Plaza, 
    New York, NY 10278 (212-264-2881); U.S. EPA Public Information Office, 
    Carborundum Center, Suite 530, 345 Third Street, Niagara Falls, NY 
    14303 (716-285-8842); New York State Department of Environmental 
    Conservation (NYSDEC), Room 310, 50 Wolf Road, Albany, NY 12333 (518-
    457-7463); NYSDEC, Region 6, 7th Floor, State Office Building, 317 
    Washington Street, Watertown, NY 13602 (315-785-2513); NYSDEC, Region 
    7, 615 Erie Boulevard West, Syracuse, NY 13204 (315-426-7400); NYSDEC, 
    Region 8, 6274 East Avon-Lima Road, Avon, NY 14414 (716-226-2466); 
    NYSDEC, Region 9, 270 Michigan Avenue, Buffalo, NY 14203 (716-851-7070)
        Ohio: Ohio Environmental Protection Agency Library--Central 
    District Office, 1800 Watermark Road, Columbus, OH 43215 (614-644-
    3024); U.S. EPA Eastern District Office, 25809 Central Ridge Road, 
    Westlake, OH 44145 (216-522-7260)
        Pennsylvania: Pennsylvania Department of Environmental Resources, 
    230 Chestnut Street, Meadville, PA 16335 (814-332-6945); U.S. EPA 
    Region 3 Library, 8th Floor, 841 Chestnut Building, Philadelphia, PA 
    19107-4431 (215-597-7904)
        Wisconsin: Water Resources Center, University of Wisconsin-Madison, 
    2nd Floor, 1975 Willow Drive, Madison, WI (608-262-3069)
        EPA is also making a number of documents available in electronic 
    format at no incremental cost to users of the Internet. These documents 
    include the contents of this Federal Register document, the SID, many 
    documents listed below, and other supporting materials.
        The documents listed below are also available for a fee upon 
    written request or telephone call to the National Technical Information 
    Center (NTIS), U.S. Department of Commerce, 5285 Port Royal Road, 
    Springfield, VA 22161 (telephone 800-553-6847 or 703-487-4650). 
    Alternatively, copies may be obtained for a fee upon written request or 
    telephone call to the Educational Resources Information Center/
    Clearinghouse for Science, Mathematics, and Environmental Education 
    (ERIC/CSMEE), 1200 Chambers Road, Room 310, Columbus, OH 43212 (614-
    292-6717). When ordering, please include the NTIS or ERIC/CSMEE 
    accession number.
        A. Final Water Quality Guidance for the Great Lakes System: 
    Supplementary Information Document (SID). NTIS Number: PB95187266. ERIC 
    Number: D046.
        B. Great Lakes Water Quality Initiative Criteria Document for the 
    Protection of Aquatic Life in Ambient Water. NTIS Number: PB95187282. 
    ERIC Number: D048.
        C. Great Lakes Water Quality Initiative Technical Support Document 
    for the Procedure to Determine Bioaccumulation Factors. NTIS Number: 
    PB95187290. ERIC Number: D049.
        D. Great Lakes Water Quality Initiative Criteria Document for the 
    Protection of Human Health. NTIS Number: PB95187308. ERIC Number: D050.
        E. Great Lakes Water Quality Initiative Technical Support Document 
    for Human Health Criteria and Values. NTIS Number: PB95187316. ERIC 
    Number: D051.
        F. Great Lakes Water Quality Initiative Criteria Document for the 
    Protection of Wildlife: DDT; Mercury; 2,3,7,8-TCDD; PCBs. NTIS Number: 
    PB95187324. ERIC Number: D052.
        G. Great Lakes Water Quality Initiative Technical Support Document 
    for Wildlife Criteria. NTIS Number: PB95187332. ERIC Number: D053.
        H. Assessment of Compliance Costs Resulting from Implementation of 
    the Final Great Lakes Water Quality Guidance. NTIS Number: PB95187340. 
    ERIC Number: D054.
        I. Regulatory Impact Analysis of the Final Great Lakes Water 
    Quality Guidance. NTIS Number: PB95187357. ERIC Number: D055.
    
    List of Subjects
    
    40 CFR Part 9
    
        Reporting and recordkeeping requirements.
    
    40 CFR Part 122
    
        Administrative practice and procedure, Confidential business 
    information, Great Lakes, Hazardous substances, Reporting and 
    recordkeeping requirements, Water pollution control.
    
    40 CFR Part 123
    
        Administrative practice and procedure, Confidential business 
    information, Great Lakes, Hazardous substances, Indians-lands, 
    Intergovernmental relations, Penalties, Reporting and recordkeeping 
    requirements, Water pollution control.
    
    40 CFR Part 131
    
        Great Lakes, Reporting and recordkeeping requirements, Water 
    pollution control.
    
    40 CFR Part 132
    
        Administrative practice and procedure, Great Lakes, Indians-lands, 
    Intergovernmental relations, Reporting and recordkeeping requirements, 
    Water pollution control.
    
        Dated: March 13, 1995.
    Carol M. Browner,
    Administrator.
    
        For the reasons set out in the preamble, title 40, chapter I, parts 
    9, 122, 123, and 131 are amended, and part 132 is added as follows: 
    [[Page 15386]] 
    
    PART 9--OMB APPROVALS UNDER THE PAPERWORK REDUCTION ACT
    
        1. The authority citation for part 9 continues to read as follows:
    
        Authority: 7 U.S.C. 135 et seq., 136-136y; 15 U.S.C. 2001, 2003, 
    2005, 2006, 2601-2671; 21 U.S.C. 331j, 346a, 348; 31 U.S.C. 9701; 33 
    U.S.C. 1251 et seq., 1311, 1313d, 1314, 1318, 1321, 1326, 1330, 
    1342, 1344, 1345 (d) and (e), 1361; E.O. 11735, 38 FR 21243, 3 CFR, 
    1971-1975 Comp. p. 973; 42 U.S.C. 241, 242b, 243, 246, 300f, 300g, 
    300g-1, 300g-2, 300g-3, 300g-4, 300g-5, 300g-6, 300j-1, 300j-2, 
    300j-3, 300j-4, 300j-9, 1857 et seq., 6901-6992k, 7401-7671q, 7542, 
    9601-9657, 11023, 11048.
    
        2. Section 9.1 is amended as follows:
        a. By adding in numerical order the entry ``122.44(r)'' under the 
    heading ``EPA Administered Permit Programs: The National Pollutant 
    Discharge Elimination System''.
        b. By revising the entries under the heading ``State Permit 
    Requirements'';
        c. By adding in numerical order the entries ``131.1'' and ``131.5'' 
    and by revising the entries ``131.20'', ``131.21'' and ``131.22'' under 
    the heading ``Water Quality Standards Regulations''; and
        d. By adding in numerical order a new heading and new entries for 
    ``Water Quality Guidance for the Great Lakes System'' to read as 
    follows:
    
    
    Sec. 9.1  OMB approvals under the Paperwork Reduction Act.
    
    * * * * *
    
                                                                            
                        40 CFR citation                      OMB control No.
                                                                            
       EPA Administered Permit Programs: The National Pollutant Discharge   
                               Elimination System                           
                                                                            
                      *        *        *        *        *                 
    122.44(r).............................................  2040-0180       
                     *        *        *        *        *                  
                           State Permit Requirements                        
    123.21-123.24.........................................  2040-0057,      
                                                            2040-0170       
    123.25................................................  2040-0004,      
                                                            2040-0110,      
                                                            2040-0170,      
                                                            2040-0180       
    123.26-123.29.........................................  2040-0057,      
                                                            2040-0170       
    123.43................................................  2040-0057,      
                                                            2040-0170       
    123.44................................................  2040-0057,      
                                                            2040-0170,      
                                                            2040-0180       
    123.45................................................  2040-0057,      
                                                            2040-0170       
    123.62................................................  2040-0057,      
                                                            2040-0170,      
                                                            2040-0180       
    123.63................................................  2040-0057,      
                                                            2040-0170,      
                                                            2040-0180       
    123.64................................................  2040-0057,      
                                                            2040-0170       
                       Water Quality Standards Regulation                   
    131.1.................................................  2040-0180       
    131.5.................................................  2040-0180       
                                                                            
                      *        *        *        *        *                 
    131.20................................................  2040-0049       
    131.21................................................  2040-0049,      
                                                            2040-0180       
    131.22................................................  2040-0049       
                                                                            
                     *        *        *        *          *                
               Water Quality Guidance for the Great Lakes System            
    132.1.................................................  2040-0180       
    132.2.................................................  2040-0180       
    132.3.................................................  2040-0180       
    132.4.................................................  2040-0180       
    132.5.................................................  2040-0180       
    Appendix A............................................  2040-0180       
    Appendix B............................................  2040-0180       
    Appendix C............................................  2040-0180       
    Appendix D............................................  2040-0180       
    Appendix E............................................  2040-0180       
    Appendix F............................................  2040-0180       
                                                                            
    
    * * * * *
    
    PART 122--EPA ADMINISTERED PERMIT PROGRAMS: THE NATIONAL POLLUTANT 
    DISCHARGE ELIMINATION SYSTEM
    
        3. The authority citation for part 122 continues to read as 
    follows:
    
        Authority: The Clean Water Act, 33 U.S.C. 1251 et seq.
    
        4. Section 122.44 is amended by adding a new paragraph (r) to read 
    as follows:
    
    
    Sec. 122.44  Establishing limitations, standards, and other permit 
    conditions (applicable to State NPDES programs, see Sec. 123.25).
    
    * * * * *
        (r) Great Lakes. When a permit is issued to a facility that 
    discharges into the Great Lakes System (as defined in 40 CFR 132.2), 
    conditions promulgated by the State, Tribe, or EPA pursuant to 40 CFR 
    part 132.
    
    PART 123--STATE PROGRAM REQUIREMENTS
    
        5. The authority citation for part 123 continues to read as 
    follows:
    
        Authority: Clean Water Act, 33 U.S.C. 1251 et seq.
    
        6. Section 123.25 is amended by removing ``and'' at the end of 
    paragraph (a)(36), removing the period at the end of paragraph (a)(37) 
    and adding ``; and'' in its place, and adding a new paragraph (a)(38) 
    to read as follows:
    
    
    Sec. 123.25  Requirements for permitting.
    
        (a) * * *
        (38) For a Great Lakes State or Tribe (as defined in 40 CFR 132.2), 
    40 CFR part 132 (NPDES permitting implementation procedures only).
    * * * * *
        7. Section 123.44 is amended by adding a new paragraph (c)(9) to 
    read as follows:
    
    
    Sec. 123.44  EPA review of and objections to State permits.
    
    * * * * *
        (c) * * *
        (9) For a permit issued by a Great Lakes State or Tribe (as defined 
    in 40 CFR 132.2), the permit does not satisfy the conditions 
    promulgated by the State, Tribe, or EPA pursuant to 40 CFR part 132.
    * * * * *
        8. Section 123.62 is amended by adding a new paragraph (f) to read 
    as follows:
    
    
    Sec. 123.62  Procedures for revision of State programs.
    
    * * * * *
        (f) Revision of a State program by a Great Lakes State or Tribe (as 
    defined in 40 CFR 132.2) to conform to section 118 of the CWA and 40 
    CFR part 132 shall be accomplished pursuant to 40 CFR part 132.
        9. Section 123.63 is amended by adding a new paragraph (a)(6) and 
    adding and reserving paragraph (b) to read as follows:
    
    
    Sec. 123.63  Criteria for withdrawal of State programs.
    
        (a) * * *
        (6) Where a Great Lakes State or Tribe (as defined in 40 CFR 132.2) 
    fails to adequately incorporate the NPDES permitting implementation 
    procedures promulgated by the State, Tribe, or EPA pursuant to 40 CFR 
    part 132 into individual permits.
        (b) [Reserved]
    
    PART 131--WATER QUALITY STANDARDS
    
        10. The authority citation for part 131 continues to read as 
    follows:
    
        Authority: 33 U.S.C. 1251 et seq.
    
        11. Section 131.1 is revised to read as follows:
    
    
    Sec. 131.1  Scope.
    
        This part describes the requirements and procedures for developing, 
    reviewing, revising, and approving water quality standards by the 
    States as authorized by section 303(c) of the Clean Water Act. 
    Additional specific procedures for developing, reviewing, revising, and 
    approving water quality standards for Great Lakes States or Great Lakes 
    Tribes (as defined in 40 CFR 132.2) to conform to section 118 of the 
    [[Page 15387]] Clean Water Act and 40 CFR part 132, are provided in 40 
    CFR part 132.
        12. Section 131.5 is amended by revising paragraph (a)(5), by 
    redesignating paragraph (b) as paragraph (c), and by adding a new 
    paragraph (b) to read as follows:
    
    
    Sec. 131.5  EPA Authority.
    
        (a) * * *
        (5) Whether the State submission meets the requirements included in 
    Sec. 131.6 of this part and, for Great Lakes States or Great Lakes 
    Tribes (as defined in 40 CFR 132.2) to conform to section 118 of the 
    Act, the requirements of 40 CFR part 132.
        (b) If EPA determines that the State's or Tribe's water quality 
    standards are consistent with the factors listed in paragraphs (a)(1) 
    through (a)(5) of this section, EPA approves the standards. EPA must 
    disapprove the State's or Tribe's water quality standards and 
    promulgate Federal standards under section 303(c)(4), and for Great 
    Lakes States or Great Lakes Tribes under section 118(c)(2)(C) of the 
    Act, if State or Tribal adopted standards are not consistent with the 
    factors listed in paragraphs (a)(1) through (a)(5) of this section. EPA 
    may also promulgate a new or revised standard when necessary to meet 
    the requirements of the Act.
    * * * * *
        13. Section 131.21 is amended by revising paragraph (b) to read as 
    follows:
    
    
    Sec. 131.21  EPA review and approval of water quality standards.
    
    * * * * *
        (b) The Regional Administrator's approval or disapproval of a State 
    water quality standard shall be based on the requirements of the Act as 
    described in Secs. 131.5 and 131.6, and, with respect to Great Lakes 
    States or Tribes (as defined in 40 CFR 132.2), 40 CFR part 132.
    * * * * *
        14. Part 132 is added as follows:
    
    PART 132--WATER QUALITY GUIDANCE FOR THE GREAT LAKES SYSTEM
    
    Sec.
    132.1  Scope, purpose, and availability of documents.
    132.2  Definitions.
    132.3  Adoption of criteria.
    132.4   State adoption and application of methodologies, policies 
    and procedures.
    132.5  Procedures for adoption and EPA review.
    132.6  Application of part 132 requirements in Great Lakes States 
    and Tribes. [Reserved]
    
    Tables to Part 132
    
    Appendix A to Part 132--Great Lakes Water Quality Initiative 
    Methodologies for Development of Aquatic Life Criteria and Values
    Appendix B to Part 132--Great Lakes Water Quality Initiative 
    Methodology for Development of Bioaccumulation Factors
    Appendix C to Part 132--Great Lakes Water Quality Initiative 
    Methodology for Development of Human Health Criteria and Values
    Appendix D to Part 132--Great Lakes Water Quality Initiative 
    Methodology for the Development of Wildlife Criteria
    Appendix E to Part 132--Great Lakes Water Quality Initiative 
    Antidegradation Policy
    Appendix F to Part 132--Great Lakes Water Quality Initiative 
    Implementation Procedures
    
        Authority: 33 U.S.C. 1251 et seq.
    
    
    Sec. 132.1  Scope, purpose, and availability of documents.
    
        (a) This part constitutes the Water Quality Guidance for the Great 
    Lakes System (Guidance) required by section 118(c)(2) of the Clean 
    Water Act (33 U.S.C. 1251 et seq.) as amended by the Great Lakes 
    Critical Programs Act of 1990 (Pub. L. 101-596, 104 Stat. 3000 et 
    seq.). The Guidance in this part identifies minimum water quality 
    standards, antidegradation policies, and implementation procedures for 
    the Great Lakes System to protect human health, aquatic life, and 
    wildlife.
        (b) The U.S. Environmental Protection Agency, Great Lakes States, 
    and Great Lakes Tribes will use the Guidance in this part to evaluate 
    the water quality programs of the States and Tribes to assure that they 
    are protective of water quality. State and Tribal programs do not need 
    to be identical to the Guidance in this part, but must contain 
    provisions that are consistent with (as protective as) the Guidance in 
    this part. The scientific, policy and legal basis for EPA's development 
    of each section of the final Guidance in this part is set forth in the 
    preamble, Supplementary Information Document, Technical Support 
    Documents, and other supporting documents in the public docket. EPA 
    will follow the guidance set out in these documents in reviewing the 
    State and Tribal water quality programs in the Great Lakes for 
    consistency with this part.
        (c) The Great Lakes States and Tribes must adopt provisions 
    consistent with the Guidance in this part applicable to waters in the 
    Great Lakes System or be subject to EPA promulgation of its terms 
    pursuant to this part.
        (d) EPA understands that the science of risk assessment is rapidly 
    improving. Therefore, to ensure that the scientific basis for the 
    methodologies in appendices A through D are always current and peer 
    reviewed, EPA will review the methodologies and revise them, as 
    appropriate, every 3 years.
        (e) Certain documents referenced in the appendixes to this part 
    with a designation of NTIS and/or ERIC are available for a fee upon 
    request to the National Technical Information Center (NTIS), U.S. 
    Department of Commerce, 5285 Port Royal Road, Springfield, VA 22161. 
    Alternatively, copies may be obtained for a fee upon request to the 
    Educational Resources Information Center/Clearinghouse for Science, 
    Mathematics, and Environmental Education (ERIC/CSMEE), 1200 Chambers 
    Road, Room 310, Columbus, Ohio 43212. When ordering, please include the 
    NTIS or ERIC/CSMEE accession number.
    
    
    Sec. 132.2  Definitions.
    
        The following definitions apply in this part. Terms not defined in 
    this section have the meaning given by the Clean Water Act and EPA 
    implementing regulations.
        Acute-chronic ratio (ACR) is a standard measure of the acute 
    toxicity of a material divided by an appropriate measure of the chronic 
    toxicity of the same material under comparable conditions.
        Acute toxicity is concurrent and delayed adverse effect(s) that 
    results from an acute exposure and occurs within any short observation 
    period which begins when the exposure begins, may extend beyond the 
    exposure period, and usually does not constitute a substantial portion 
    of the life span of the organism.
        Adverse effect is any deleterious effect to organisms due to 
    exposure to a substance. This includes effects which are or may become 
    debilitating, harmful or toxic to the normal functions of the organism, 
    but does not include non-harmful effects such as tissue discoloration 
    alone or the induction of enzymes involved in the metabolism of the 
    substance.
        Bioaccumulation is the net accumulation of a substance by an 
    organism as a result of uptake from all environmental sources.
        Bioaccumulation factor (BAF) is the ratio (in L/kg) of a 
    substance's concentration in tissue of an aquatic organism to its 
    concentration in the ambient water, in situations where both the 
    organism and its food are exposed and the ratio does not change 
    substantially over time.
        Bioaccumulative chemical of concern (BCC) is any chemical that has 
    the potential to cause adverse effects which, upon entering the surface 
    waters, by itself or as its toxic transformation 
    [[Page 15388]] product, accumulates in aquatic organisms by a human 
    health bioaccumulation factor greater than 1000, after considering 
    metabolism and other physicochemical properties that might enhance or 
    inhibit bioaccumulation, in accordance with the methodology in appendix 
    B of this part. Chemicals with half-lives of less than eight weeks in 
    the water column, sediment, and biota are not BCCs. The minimum BAF 
    information needed to define an organic chemical as a BCC is either a 
    field-measured BAF or a BAF derived using the BSAF methodology. The 
    minimum BAF information needed to define an inorganic chemical, 
    including an organometal, as a BCC is either a field-measured BAF or a 
    laboratory-measured BCF. BCCs include, but are not limited to, the 
    pollutants identified as BCCs in section A of Table 6 of this part.
        Bioconcentration is the net accumulation of a substance by an 
    aquatic organism as a result of uptake directly from the ambient water 
    through gill membranes or other external body surfaces.
        Bioconcentration factor (BCF) is the ratio (in L/kg) of a 
    substance's concentration in tissue of an aquatic organism to its 
    concentration in the ambient water, in situations where the organism is 
    exposed through the water only and the ratio does not change 
    substantially over time.
        Biota-sediment accumulation factor (BSAF) is the ratio (in kg of 
    organic carbon/kg of lipid) of a substance's lipid-normalized 
    concentration in tissue of an aquatic organism to its organic carbon-
    normalized concentration in surface sediment, in situations where the 
    ratio does not change substantially over time, both the organism and 
    its food are exposed, and the surface sediment is representative of 
    average surface sediment in the vicinity of the organism.
        Carcinogen is a substance which causes an increased incidence of 
    benign or malignant neoplasms, or substantially decreases the time to 
    develop neoplasms, in animals or humans. The classification of 
    carcinogens is discussed in section II.A of appendix C to part 132.
        Chronic toxicity is concurrent and delayed adverse effect(s) that 
    occurs only as a result of a chronic exposure.
        Connecting channels of the Great Lakes are the Saint Mary's River, 
    Saint Clair River, Detroit River, Niagara River, and Saint Lawrence 
    River to the Canadian Border.
        Criterion continuous concentration (CCC) is an estimate of the 
    highest concentration of a material in the water column to which an 
    aquatic community can be exposed indefinitely without resulting in an 
    unacceptable effect.
        Criterion maximum concentration (CMC) is an estimate of the highest 
    concentration of a material in the water column to which an aquatic 
    community can be exposed briefly without resulting in an unacceptable 
    effect.
        EC50 is a statistically or graphically estimated concentration that 
    is expected to cause one or more specified effects in 50 percent of a 
    group of organisms under specified conditions.
        Endangered or threatened species are those species that are listed 
    as endangered or threatened under section 4 of the Endangered Species 
    Act.
        Existing Great Lakes discharger is any building, structure, 
    facility, or installation from which there is or may be a ``discharge 
    of pollutants'' (as defined in 40 CFR 122.2) to the Great Lakes System, 
    that is not a new Great Lakes discharger.
        Federal Indian reservation, Indian reservation, or reservation 
    means all land within the limits of any Indian reservation under the 
    jurisdiction of the United States Government, notwithstanding the 
    issuance of any patent, and including rights-of-way running through the 
    reservation.
        Final acute value (FAV) is (a) a calculated estimate of the 
    concentration of a test material such that 95 percent of the genera 
    (with which acceptable acute toxicity tests have been conducted on the 
    material) have higher GMAVs, or (b) the SMAV of an important and/or 
    critical species, if the SMAV is lower than the calculated estimate.
        Final chronic value (FCV) is (a) a calculated estimate of the 
    concentration of a test material such that 95 percent of the genera 
    (with which acceptable chronic toxicity tests have been conducted on 
    the material) have higher GMCVs, (b) the quotient of an FAV divided by 
    an appropriate acute-chronic ratio, or (c) the SMCV of an important 
    and/or critical species, if the SMCV is lower than the calculated 
    estimate or the quotient, whichever is applicable.
        Final plant value (FPV) is the lowest plant value that was obtained 
    with an important aquatic plant species in an acceptable toxicity test 
    for which the concentrations of the test material were measured and the 
    adverse effect was biologically important.
        Genus mean acute value (GMAV) is the geometric mean of the SMAVs 
    for the genus.
        Genus mean chronic value (GMCV) is the geometric mean of the SMCVs 
    for the genus.
        Great Lakes means Lake Ontario, Lake Erie, Lake Huron (including 
    Lake St. Clair), Lake Michigan, and Lake Superior; and the connecting 
    channels (Saint Mary's River, Saint Clair River, Detroit River, Niagara 
    River, and Saint Lawrence River to the Canadian Border).
        Great Lakes States and Great Lakes Tribes, or Great Lakes States 
    and Tribes means the States of Illinois, Indiana, Michigan, Minnesota, 
    New York, Ohio, Pennsylvania, and Wisconsin, and any Indian Tribe as 
    defined in this part which is located in whole or in part within the 
    drainage basin of the Great Lakes, and for which EPA has approved water 
    quality standards under section 303 of the Clean Water Act or which EPA 
    has authorized to administer an NPDES program under section 402 of the 
    Clean Water Act.
        Great Lakes System means all the streams, rivers, lakes and other 
    bodies of water within the drainage basin of the Great Lakes within the 
    United States.
        Human cancer criterion (HCC) is a Human Cancer Value (HCV) for a 
    pollutant that meets the minimum data requirements for Tier I specified 
    in appendix C of this part.
        Human cancer value (HCV) is the maximum ambient water concentration 
    of a substance at which a lifetime of exposure from either: drinking 
    the water, consuming fish from the water, and water-related recreation 
    activities; or consuming fish from the water, and water-related 
    recreation activities, will represent a plausible upper-bound risk of 
    contracting cancer of one in 100,000 using the exposure assumptions 
    specified in the Methodologies for the Development of Human Health 
    Criteria and Values in appendix C of this part.
        Human noncancer criterion (HNC) is a Human Noncancer Value (HNV) 
    for a pollutant that meets the minimum data requirements for Tier I 
    specified in appendix C of this part.
        Human noncancer value (HNV) is the maximum ambient water 
    concentration of a substance at which adverse noncancer effects are not 
    likely to occur in the human population from lifetime exposure via 
    either: drinking the water, consuming fish from the water, and water-
    related recreation activities; or consuming fish from the water, and 
    water-related recreation activities using the Methodologies for the 
    Development of Human Health Criteria and Values in appendix C of this 
    part.
        Indian Tribe or Tribe means any Indian Tribe, band, group, or 
    community recognized by the Secretary of the Interior and exercising 
    governmental authority over a Federal Indian reservation.
        LC50 is a statistically or graphically estimated concentration that 
    is expected [[Page 15389]] to be lethal to 50 percent of a group of 
    organisms under specified conditions.
        Load allocation (LA) is the portion of a receiving water's loading 
    capacity that is attributed either to one of its existing or future 
    nonpoint sources or to natural background sources, as more fully 
    defined at 40 CFR 130.2(g). Nonpoint sources include: in-place 
    contaminants, direct wet and dry deposition, groundwater inflow, and 
    overland runoff.
        Loading capacity is the greatest amount of loading that a water can 
    receive without violating water quality standards.
        Lowest observed adverse effect level (LOAEL) is the lowest tested 
    dose or concentration of a substance which resulted in an observed 
    adverse effect in exposed test organisms when all higher doses or 
    concentrations resulted in the same or more severe effects.
        Method detection level is the minimum concentration of an analyte 
    (substance) that can be measured and reported with a 99 percent 
    confidence that the analyte concentration is greater than zero as 
    determined by the procedure set forth in appendix B of 40 CFR part 136.
        Minimum Level (ML) is the concentration at which the entire 
    analytical system must give a recognizable signal and acceptable 
    calibration point. The ML is the concentration in a sample that is 
    equivalent to the concentration of the lowest calibration standard 
    analyzed by a specific analytical procedure, assuming that all the 
    method-specified sample weights, volumes and processing steps have been 
    followed.
        New Great Lakes discharger is any building, structure, facility, or 
    installation from which there is or may be a ``discharge of 
    pollutants'' (as defined in 40 CFR 122.2) to the Great Lakes System, 
    the construction of which commenced after March 23, 1997.
        No observed adverse effect level (NOAEL) is the highest tested dose 
    or concentration of a substance which resulted in no observed adverse 
    effect in exposed test organisms where higher doses or concentrations 
    resulted in an adverse effect.
        No observed effect concentration (NOEC) is the highest 
    concentration of toxicant to which organisms are exposed in a full 
    life-cycle or partial life-cycle (short-term) test, that causes no 
    observable adverse effects on the test organisms (i.e., the highest 
    concentration of toxicant in which the values for the observed 
    responses are not statistically significantly different from the 
    controls).
        Open waters of the Great Lakes (OWGLs) means all of the waters 
    within Lake Erie, Lake Huron (including Lake St. Clair), Lake Michigan, 
    Lake Ontario, and Lake Superior lakeward from a line drawn across the 
    mouth of tributaries to the Lakes, including all waters enclosed by 
    constructed breakwaters, but not including the connecting channels.
        Quantification level is a measurement of the concentration of a 
    contaminant obtained by using a specified laboratory procedure 
    calibrated at a specified concentration above the method detection 
    level. It is considered the lowest concentration at which a particular 
    contaminant can be quantitatively measured using a specified laboratory 
    procedure for monitoring of the contaminant.
        Quantitative structure activity relationship (QSAR) or structure 
    activity relationship (SAR) is a mathematical relationship between a 
    property (activity) of a chemical and a number of descriptors of the 
    chemical. These descriptors are chemical or physical characteristics 
    obtained experimentally or predicted from the structure of the 
    chemical.
        Risk associated dose (RAD) is a dose of a known or presumed 
    carcinogenic substance in (mg/kg)/day which, over a lifetime of 
    exposure, is estimated to be associated with a plausible upper bound 
    incremental cancer risk equal to one in 100,000.
        Species mean acute value (SMAV) is the geometric mean of the 
    results of all acceptable flow-through acute toxicity tests (for which 
    the concentrations of the test material were measured) with the most 
    sensitive tested life stage of the species. For a species for which no 
    such result is available for the most sensitive tested life stage, the 
    SMAV is the geometric mean of the results of all acceptable acute 
    toxicity tests with the most sensitive tested life stage.
        Species mean chronic value (SMCV) is the geometric mean of the 
    results of all acceptable life-cycle and partial life-cycle toxicity 
    tests with the species; for a species of fish for which no such result 
    is available, the SMCV is the geometric mean of all acceptable early 
    life-stage tests.
        Stream design flow is the stream flow that represents critical 
    conditions, upstream from the source, for protection of aquatic life, 
    human health, or wildlife.
        Threshold effect is an effect of a substance for which there is a 
    theoretical or empirically established dose or concentration below 
    which the effect does not occur.
        Tier I criteria are numeric values derived by use of the Tier I 
    methodologies in appendixes A, C and D of this part, the methodology in 
    appendix B of this part, and the procedures in appendix F of this part, 
    that either have been adopted as numeric criteria into a water quality 
    standard or are used to implement narrative water quality criteria.
        Tier II values are numeric values derived by use of the Tier II 
    methodologies in appendixes A and C of this part, the methodology in 
    appendix B of this part, and the procedures in appendix F of this part, 
    that are used to implement narrative water quality criteria.
        Total maximum daily load (TMDL) is the sum of the individual 
    wasteload allocations for point sources and load allocations for 
    nonpoint sources and natural background, as more fully defined at 40 
    CFR 130.2(i). A TMDL sets and allocates the maximum amount of a 
    pollutant that may be introduced into a water body and still assure 
    attainment and maintenance of water quality standards.
        Tributaries of the Great Lakes System means all waters of the Great 
    Lakes System that are not open waters of the Great Lakes, or connecting 
    channels.
        Uncertainty factor (UF) is one of several numeric factors used in 
    operationally deriving criteria from experimental data to account for 
    the quality or quantity of the available data.
        Uptake is acquisition of a substance from the environment by an 
    organism as a result of any active or passive process.
        Wasteload allocation (WLA) is the portion of a receiving water's 
    loading capacity that is allocated to one of its existing or future 
    point sources of pollution, as more fully defined at 40 CFR 130.2(h). 
    In the absence of a TMDL approved by EPA pursuant to 40 CFR 130.7 or an 
    assessment and remediation plan developed and approved in accordance 
    with procedure 3.A of appendix F of this part, a WLA is the allocation 
    for an individual point source, that ensures that the level of water 
    quality to be achieved by the point source is derived from and complies 
    with all applicable water quality standards.
        Wet weather point source means any discernible, confined and 
    discrete conveyance from which pollutants are, or may be, discharged as 
    the result of a wet weather event. Discharges from wet weather point 
    sources shall include only: discharges of storm water from a municipal 
    separate storm sewer as defined at 40 CFR 122.26(b)(8); storm water 
    discharge associated with industrial activity as defined at 40 CFR 
    122.26(b)(14); discharges of storm water and sanitary wastewaters 
    (domestic, [[Page 15390]] commercial, and industrial) from a combined 
    sewer overflow; or any other stormwater discharge for which a permit is 
    required under section 402(p) of the Clean Water Act. A storm water 
    discharge associated with industrial activity which is mixed with 
    process wastewater shall not be considered a wet weather point source.
    
    
    Sec. 132.3   Adoption of criteria.
    
        The Great Lakes States and Tribes shall adopt numeric water quality 
    criteria for the purposes of section 303(c) of the Clean Water Act 
    applicable to waters of the Great Lakes System in accordance with 
    Sec. 132.4(d) that are consistent with:
        (a) The acute water quality criteria for protection of aquatic life 
    in Table 1 of this part, or a site-specific modification thereof in 
    accordance with procedure 1 of appendix F of this part;
        (b) The chronic water quality criteria for protection of aquatic 
    life in Table 2 of this part, or a site-specific modification thereof 
    in accordance with procedure 1 of appendix F of this part;
        (c) The water quality criteria for protection of human health in 
    Table 3 of this part, or a site-specific modification thereof in 
    accordance with procedure 1 of appendix F of this part; and
        (d) The water quality criteria for protection of wildlife in Table 
    4 of this part, or a site-specific modification thereof in accordance 
    with procedure 1 of appendix F of this part.
    
    
    Sec. 132.4  State adoption and application of methodologies, policies 
    and procedures.
    
        (a) The Great Lakes States and Tribes shall adopt requirements 
    applicable to waters of the Great Lakes System for the purposes of 
    sections 118, 301, 303, and 402 of the Clean Water Act that are 
    consistent with:
        (1) The definitions in Sec. 132.2;
        (2) The Methodologies for Development of Aquatic Life Criteria and 
    Values in appendix A of this part;
        (3) The Methodology for Development of Bioaccumulation Factors in 
    appendix B of this part;
        (4) The Methodologies for Development of Human Health Criteria and 
    Values in appendix C of this part;
        (5) The Methodology for Development of Wildlife Criteria in 
    appendix D of this part;
        (6) The Antidegradation Policy in appendix E of this part; and
        (7) The Implementation Procedures in appendix F of this part.
        (b) Except as provided in paragraphs (g), (h), and (i) of this 
    section, the Great Lakes States and Tribes shall use methodologies 
    consistent with the methodologies designated as Tier I methodologies in 
    appendixes A, C, and D of this part, the methodology in appendix B of 
    this part, and the procedures in appendix F of this part when adopting 
    or revising numeric water quality criteria for the purposes of section 
    303(c) of the Clean Water Act for the Great Lakes System.
        (c) Except as provided in paragraphs (g), (h), and (i) of this 
    section, the Great Lakes States and Tribes shall use methodologies and 
    procedures consistent with the methodologies designated as Tier I 
    methodologies in appendixes A, C, and D of this part, the Tier II 
    methodologies in appendixes A and C of this part, the methodology in 
    appendix B of this part, and the procedures in appendix F of this part 
    to develop numeric criteria and values when implementing narrative 
    water quality criteria adopted for purposes of section 303(c) of the 
    Clean Water Act.
        (d) The water quality criteria and values adopted or developed 
    pursuant to paragraphs (a) through (c) of this section shall apply as 
    follows:
        (1) The acute water quality criteria and values for the protection 
    of aquatic life, or site-specific modifications thereof, shall apply to 
    all waters of the Great Lakes System.
        (2) The chronic water quality criteria and values for the 
    protection of aquatic life, or site-specific modifications thereof, 
    shall apply to all waters of the Great Lakes System.
        (3) The water quality criteria and values for protection of human 
    health, or site-specific modifications thereof, shall apply as follows:
        (i) Criteria and values derived as HCV-Drinking and HNV-Drinking 
    shall apply to the Open Waters of the Great Lakes, all connecting 
    channels of the Great Lakes, and all other waters of the Great Lakes 
    System that have been designated as public water supplies by any State 
    or Tribe in accordance with 40 CFR 131.10.
        (ii) Criteria and values derived as HCV-Nondrinking and HNV-
    Nondrinking shall apply to all waters of the Great Lakes System other 
    than those in paragraph (d)(3)(i) of this section.
        (4) Criteria for protection of wildlife, or site-specific 
    modifications thereof, shall apply to all waters of the Great Lakes 
    System.
        (e) The Great Lakes States and Tribes shall apply implementation 
    procedures consistent with the procedures in appendix F of this part 
    for all applicable purposes under the Clean Water Act, including 
    developing total maximum daily loads for the purposes of section 303(d) 
    and water quality-based effluent limits for the purposes of section 
    402, in establishing controls on the discharge of any pollutant to the 
    Great Lakes System by any point source with the following exceptions:
        (1) The Great Lakes States and Tribes are not required to apply 
    these implementation procedures in establishing controls on the 
    discharge of any pollutant by a wet weather point source. Any adopted 
    implementation procedures shall conform with all applicable Federal, 
    State and Tribal requirements.
        (2) The Great Lakes States and Tribes may, but are not required to, 
    apply procedures consistent with procedures 1, 2, 3, 4, 5, 7, 8, and 9 
    of appendix F of this part in establishing controls on the discharge of 
    any pollutant set forth in Table 5 of this part. Any procedures applied 
    in lieu of these implementation procedures shall conform with all 
    applicable Federal, State, and Tribal requirements.
        (f) The Great Lakes States and Tribes shall apply an 
    antidegradation policy consistent with the policy in appendix E for all 
    applicable purposes under the Clean Water Act, including 40 CFR 131.12.
        (g) For pollutants listed in Table 5 of this part, the Great Lakes 
    States and Tribes shall:
        (1) Apply any methodologies and procedures acceptable under 40 CFR 
    part 131 when developing water quality criteria or implementing 
    narrative criteria; and
        (2) Apply the implementation procedures in appendix F of this part 
    or alternative procedures consistent with all applicable Federal, 
    State, and Tribal laws.
        (h) For any pollutant other than those in Table 5 of this part for 
    which the State or Tribe demonstrates that a methodology or procedure 
    in this part is not scientifically defensible, the Great Lakes States 
    and Tribes shall:
        (1) Apply an alternative methodology or procedure acceptable under 
    40 CFR part 131 when developing water quality criteria; or
        (2) Apply an alternative implementation procedure that is 
    consistent with all applicable Federal, State, and Tribal laws.
        (i) Nothing in this part shall prohibit the Great Lakes States and 
    Tribes from adopting numeric water quality criteria, narrative 
    criteria, or water quality values that are more stringent than criteria 
    or values specified in Sec. 132.3 or that would be derived from 
    application of the methodologies set forth in appendixes A, B, C, and D 
    of this part, or to adopt antidegradation standards and implementation 
    procedures more [[Page 15391]] stringent than those set forth in 
    appendixes E and F of this part.
    
    
    Sec. 132.5  Procedures for adoption and EPA review.
    
        (a) Except as provided in paragraph (c) of this section, the Great 
    Lakes States and Tribes shall adopt and submit for EPA review and 
    approval the criteria, methodologies, policies, and procedures 
    developed pursuant to this part no later than September 23, 1996.
        (b) The following elements must be included in each submission to 
    EPA for review:
        (1) The criteria, methodologies, policies, and procedures developed 
    pursuant to this part;
        (2) Certification by the Attorney General or other appropriate 
    legal authority pursuant to 40 CFR 123.62 and 40 CFR 131.6(e) as 
    appropriate;
        (3) All other information required for submission of National 
    Pollutant Discharge Elimination System (NPDES) program modifications 
    under 40 CFR 123.62; and
        (4) General information which will aid EPA in determining whether 
    the criteria, methodologies, policies and procedures are consistent 
    with the requirements of the Clean Water Act and this part, as well as 
    information on general policies which may affect their application and 
    implementation.
        (c) The Regional Administrator may extend the deadline for the 
    submission required in paragraph (a) of this section if the Regional 
    Administrator believes that the submission will be consistent with the 
    requirements of this part and can be reviewed and approved pursuant to 
    this section no later than March 23, 1997.
        (d) If a Great Lakes State or Tribe makes no submission pursuant to 
    this part to EPA for review, the requirements of this part shall apply 
    to discharges to waters of the Great Lakes System located within the 
    State or Federal Indian reservation upon EPA's publication of a final 
    rule indicating the effective date of the part 132 requirements in the 
    identified jurisdictions.
        (e) If a Great Lakes State or Tribe submits criteria, 
    methodologies, policies, and procedures pursuant to this part to EPA 
    for review that contain substantial modifications of the State or 
    Tribal NPDES program, EPA shall issue public notice and provide a 
    minimum of 30 days for public comment on such modifications. The public 
    notice shall conform with the requirements of 40 CFR 123.62.
        (f) After review of State or Tribal submissions under this section, 
    and following the public comment period in subparagraph (e) of this 
    section, if any, EPA shall either:
        (1) Publish notice of approval of the submission in the Federal 
    Register within 90 days of such submission; or
        (2) Notify the State or Tribe within 90 days of such submission 
    that EPA has determined that all or part of the submission is 
    inconsistent with the requirements of the Clean Water Act or this part 
    and identify any necessary changes to obtain EPA approval. If the State 
    or Tribe fails to adopt such changes within 90 days after the 
    notification, EPA shall publish a notice in the Federal Register 
    identifying the approved and disapproved elements of the submission and 
    a final rule in the Federal Register identifying the provisions of part 
    132 that shall apply to discharges within the State or Federal Indian 
    reservation.
        (g) EPA's approval or disapproval of a State or Tribal submission 
    shall be based on the requirements of this part and of the Clean Water 
    Act. EPA's determination whether the criteria, methodologies, policies, 
    and procedures in a State or Tribal submission are consistent with the 
    requirements of this part will be based on whether:
        (1) For pollutants listed in Tables 1, 2, 3, and 4 of this part. 
    The Great Lakes State or Tribe has adopted numeric water quality 
    criteria as protective as each of the numeric criteria in Tables 1, 2, 
    3, and 4 of this part, taking into account any site-specific criteria 
    modifications in accordance with procedure 1 of appendix F of this 
    part;
        (2) For pollutants other than those listed in Tables 1, 2, 3, 4, 
    and 5 of this part. The Great Lakes State or Tribe demonstrates that 
    either:
        (i) It has adopted numeric criteria in its water quality standards 
    that were derived, or are as protective as or more protective than 
    could be derived, using the methodologies in appendixes A, B, C, and D 
    of this part, and the site-specific criteria modification procedures in 
    accordance with procedure 1 of appendix F of this part; or
        (ii) It has adopted a procedure by which water quality-based 
    effluent limits and total maximum daily loads are developed using the 
    more protective of:
        (A) Numeric criteria adopted by the State into State water quality 
    standards and approved by EPA prior to March 23, 1997; or
        (B) Water quality criteria and values derived pursuant to 
    Sec. 132.4(c); and
        (3) For methodologies, policies, and procedures. The Great Lakes 
    State or Tribe has adopted methodologies, policies, and procedures as 
    protective as the corresponding methodology, policy, or procedure in 
    Sec. 132.4. The Great Lakes State or Tribe may adopt provisions that 
    are more protective than those contained in this part. Adoption of a 
    more protective element in one provision may be used to offset a less 
    protective element in the same provision as long as the adopted 
    provision is as protective as the corresponding provision in this part; 
    adoption of a more protective element in one provision, however, is not 
    justification for adoption of a less protective element in another 
    provision of this part.
        (h) A submission by a Great Lakes State or Tribe will need to 
    include any provisions that EPA determines, based on EPA's authorities 
    under the Clean Water Act and the results of consultation under section 
    7 of the Endangered Species Act, are necessary to ensure that water 
    quality is not likely to jeopardize the continued existence of any 
    endangered or threatened species listed under section 4 of the 
    Endangered Species Act or result in the destruction or adverse 
    modification of such species' critical habitat.
        (i) EPA's approval of the elements of a State's or Tribe's 
    submission will constitute approval under section 118 of the Clean 
    Water Act, approval of the submitted water quality standards pursuant 
    to section 303 of the Clean Water Act, and approval of the submitted 
    modifications to the State's or Tribe's NPDES program pursuant to 
    section 402 of the Clean Water Act.
    
    
    Sec. 132.6  Application of part 132 requirements in Great Lakes States 
    and Tribes. [Reserved]
    
    Tables to Part 132
    
    Table 1.--Acute Water Quality Criteria for Protection of Aquatic Life 
    in Ambient Water
    
        EPA recommends that metals criteria be expressed as dissolved 
    concentrations (see appendix A, I.A.4 for more information regarding 
    metals criteria).
        (a)
    
    ------------------------------------------------------------------------
                                                                  Conversion
                      Chemical                   CMC(g/    factor  
                                                        L)           (CF)   
    ------------------------------------------------------------------------
    Arsenic (III)..............................     a,b339.8          1.000 
    Chromium (VI)..............................      a,b16.02         0.982 
    Cyanide....................................        c22              n/a 
    Dieldrin...................................         d0.24           n/a 
    Endrin.....................................         d0.086          n/a 
    Lindane....................................         d0.95           n/a 
    Mercury (II)...............................       a,b1.694        0.85  
    Parathion..................................         d0.065          n/a 
    Selenium...................................      a,b19.34         0.922 
    ------------------------------------------------------------------------
    aCMC=CMCtr.                                                             
    bCMCd=(CMCtr) CF. The CMCd shall be rounded to two significant digits.  
    [[Page 15392]]                                                          
                                                                            
    cCMC should be considered free cyanide as CN.                           
    dCMC=CMCt.                                                              
                                                                            
    Notes:                                                                  
    The term ``n/a'' means not applicable.                                  
    CMC is Criterion Maximum Concentration.                                 
    CMCtr is the CMC expressed as total recoverable.                        
    CMCd is the CMC expressed as a dissolved concentration.                 
    CMCt is the CMC expressed as a total concentration.                     
    
        (b)
    
    ------------------------------------------------------------------------
                                                                  Conversion
                   Chemical                     mA         bA       factor  
                                                                     (CF)   
    ------------------------------------------------------------------------
    Cadmiuma,b............................     1.128     -3.6867      0.85  
    Chromium (III)a,b.....................     0.819     +3.7256      0.316 
    Coppera,b.............................     0.9422    -1.700       0.960 
    Nickela,b.............................     0.846     +2.255       0.998 
    Pentachlorophenolc....................     1.005     -4.869         n/a 
    Zinca,b...............................     0.8473    +0.884       0.978 
    ------------------------------------------------------------------------
    aCMCtr=exp { mA [ln (hardness)]+bA}.                                    
    bCMCd=(CMCtr) CF. The CMCd shall be rounded to two significant digits.  
    cCMCt=exp mA { [pH]+bA}. The CMCt shall be rounded to two significant   
      digits.                                                               
                                                                            
    Notes:                                                                  
    The term ``exp'' represents the base e exponential function.            
    The term ``n/a'' means not applicable.                                  
    CMC is Criterion Maximum Concentration.                                 
    CMCtr is the CMC expressed as total recoverable.                        
    CMCd is the CMC expressed as a dissolved concentration.                 
    CMCt is the CMC expressed as a total concentration.                     
    
    Table 2.--Chronic Water Quality Criteria for Protection of Aquatic Life 
    in Ambient Water
    
        EPA recommends that metals criteria be expressed as dissolved 
    concentrations (see appendix A, I.A.4 for more information regarding 
    metals criteria).
        (a)
    
    ------------------------------------------------------------------------
                                                                  Conversion
                      Chemical                   CCC(g/    factor  
                                                        L)           (CF)   
    ------------------------------------------------------------------------
    Arsenic (III)..............................    a,b147.9           1.000 
    Chromium (VI)..............................     a,b10.98          0.962 
    Cyanide....................................        c5.2             n/a 
    Dieldrin...................................        d0.056           n/a 
    Endrin.....................................        d0.036           n/a 
    Mercury (II)...............................      a,b0.9081        0.85  
    Parathion..................................        d0.013           n/a 
    Selenium...................................      a,b5             0.922 
    ------------------------------------------------------------------------
    aCCC=CCCtr.                                                             
    bCCCd=(CCCtr) CF. The CCCd shall be rounded to two significant digits.  
    cCCC should be considered free cyanide as CN.                           
    dCCC=CCCt.                                                              
                                                                            
    Notes:                                                                  
    The term ``n/a'' means not applicable.                                  
    CCC is Criterion Continuous Concentration.                              
    CCCtr is the CCC expressed as total recoverable.                        
    CCCd is the CCC expressed as a dissolved concentration.                 
    CCCt is the CCC expressed as a total concentration.                     
    
        (b)
    
    ------------------------------------------------------------------------
                                                                  Conversion
                     Chemical                      mc       bc    factor(CF)
    ------------------------------------------------------------------------
    Cadmiuma,b................................   0.7852  -2.715       0.850 
    Chromium (III)a,b.........................   0.819   +0.6848      0.860 
    Coppera,b.................................   0.8545  -1.702       0.960 
    Nickela,b.................................   0.846   +0.0584      0.997 
    Pentachlorophenolc........................   1.005   -5.134         n/a 
    Zinca,b...................................   0.8473  +0.884       0.986 
    ------------------------------------------------------------------------
    aCCCtr=exp {mc[ln (hardness)]+bc}.                                      
    bCCCd=(CCCtr) (CF). The CCCd shall be rounded to two significant digits.
    cCMCt=exp {mA[pH]+bA}. The CMCt shall be rounded to two significant     
      digits.                                                               
                                                                            
    Notes:                                                                  
    The term ``exp'' represents the base e exponential function.            
    The term ``n/a'' means not applicable.                                  
    CCC is Criterion Continuous Concentration.                              
    CCCtr is the CCC expressed as total recoverable.                        
    CCCd is the CCC expressed as a dissolved concentration.                 
    CCCt is the CCC expressed as a total concentration.                     
    
    
                             Table 3.--Water Quality Criteria for Protection of Human Health                        
    ----------------------------------------------------------------------------------------------------------------
                                                               HNV (g/L)            HCV (g/L)     
                          Chemical                       -----------------------------------------------------------
                                                             Drinking     Nondrinking      Drinking     Nondrinking 
    ----------------------------------------------------------------------------------------------------------------
    Benzene.............................................  1.9E1          5.1E2          1.2E1          3.1E2        
    Chlordane...........................................  1.4E-3         1.4E-3         2.5E-4         2.5E-4       
    Chlorobenzene.......................................  4.7E2          3.2E3                                      
    Cyanides............................................  6.0E2          4.8E4                                      
    DDT.................................................  2.0E-3         2.0E-3         1.5E-4         1.5E-4       
    Dieldrin............................................  4.1E-4         4.1E-4         6.5E-6         6.5E-6       
    2,4-Dimethylphenol..................................  4.5E2          8.7E3                                      
    2,4-Dinitrophenol...................................  5.5E1          2.8E3                                      
    Hexachlorobenzene...................................  4.6E-2         4.6E-2         4.5E-4         4.5E-4       
    Hexachloroethane....................................  6.0            7.6            5.3            6.7          
    Lindane.............................................  4.7E-1         5.0E-1                                     
    Mercury1............................................  1.8E-3         1.8E-3                                     
    Methylene chloride..................................  1.6E3          9.0E4          4.7E1          2.6E3        
    PCBs (class)........................................                                3.9E-6         3.9E-6       
    2,3,7,8-TCDD........................................  6.7E-8         6.7E-8         8.6E-9         8.6E-9       
    Toluene.............................................  5.6E3          5.1E4                                      
    Toxaphene...........................................                                6.8E-5         6.8E-5       
    [[Page 15393]]                                                                                                  
                                                                                                                    
    Trichloroethylene...................................                                2.9E1          3.7E2        
    ----------------------------------------------------------------------------------------------------------------
    \1\Includes methylmercury.                                                                                      
    
    
           Table 4.--Water Quality Criteria for Protection of Wildlife      
    ------------------------------------------------------------------------
                                                                  Criteria  
                             Chemical                           (g/
                                                                     L)     
    ------------------------------------------------------------------------
    DDT and metabolites.......................................  1.1E-5      
    Mercury (including methylmercury).........................  1.3E-3      
    PCBs (class)..............................................  7.4E-5      
    2,3,7,8-TCDD..............................................  3.1E-9      
    ------------------------------------------------------------------------
    
    Table 5.--Pollutants Subject to Federal, State, and Tribal Requirements
    
        Alkalinity
        Ammonia
        Bacteria
        Biochemical oxygen demand (BOD)
        Chlorine
        Color
        Dissolved oxygen
        Dissolved solids
        pH
        Phosphorus
        Salinity
        Temperature
        Total and suspended solids
        Turbidity
    
    Table 6.--Pollutants of Initial Focus in the Great Lakes Water Quality 
    Initiative
    
        A. Pollutants that are bioaccumulative chemicals of concern 
    (BCCs):
        Chlordane
        4,4'-DDD; p,p'-DDD; 4,4'-TDE; p,p'-TDE
        4,4'-DDE; p,p'-DDE
        4,4'-DDT; p,p'-DDT
        Dieldrin
        Hexachlorobenzene
        Hexachlorobutadiene; hexachloro-1, 3-butadiene
        Hexachlorocyclohexanes; BHCs
        alpha-Hexachlorocyclohexane; alpha-BHC
        beta-Hexachlorocyclohexane; beta-BHC
        delta-Hexachlorocyclohexane; delta-BHC
        Lindane; gamma-hexachlorocyclohexane; gamma-BHC
        Mercury
        Mirex
        Octachlorostyrene
        PCBs; polychlorinated biphenyls
        Pentachlorobenzene
        Photomirex
        2,3,7,8-TCDD; dioxin
        1,2,3,4-Tetrachlorobenzene
        1,2,4,5-Tetrachlorobenzene Toxaphene
        B. Pollutants that are not bioaccumulative chemicals of concern:
        Acenaphthene
        Acenaphthylene
        Acrolein; 2-propenal
        Acrylonitrile
        Aldrin
        Aluminum
        Anthracene
        Antimony
        Arsenic
        Asbestos
        1,2-Benzanthracene; benz[a]anthracene
        Benzene
        Benzidine
        Benzo[a]pyrene; 3,4-benzopyrene
        3,4-Benzofluoranthene; benzo[b]fluoranthene
        11,12-Benzofluoranthene; benzo[k]fluoranthene
        1,12-Benzoperylene; benzo[ghi]perylene
        Beryllium
        Bis(2-chloroethoxy) methane
        Bis(2-chloroethyl) ether
        Bis(2-chloroisopropyl) ether
        Bromoform; tribomomethane
        4-Bromophenyl phenyl ether
        Butyl benzyl phthalate
        Cadmium
        Carbon tetrachloride; tetrachloromethane
        Chlorobenzene
        p-Chloro-m-cresol; 4-chloro-3-methylphenol
        Chlorodibromomethane
        Chlorethane
        2-Chloroethyl vinyl ether
        Chloroform; trichloromethane
        2-Chloronaphthalene
        2-Chlorophenol
        4-Chlorophenyl phenyl ether
        Chlorpyrifos
        Chromium
        Chrysene
        Copper
        Cyanide
        2,4-D; 2,4-Dichlorophenoxyacetic acid
        DEHP; di(2-ethylhexyl) phthalate
        Diazinon
        1,2:5,6-Dibenzanthracene; dibenz[a,h]anthracene
        Dibutyl phthalate; di-n-butyl phthalate
        1,2-Dichlorobenzene
        1,3-Dichlorobenzene
        1,4-Dichlorobenzene
        3,3'-Dichlorobenzidine
        Dichlorobromomethane; bromodichloromethane
        1,1-Dichloroethane
        1,2-Dichloroethane
        1,1-Dichloroethylene; vinylidene chloride
        1,2-trans-Dichloroethylene
        2,4-Dichlorophenol
        1,2-Dichloropropane
        1,3-Dichloropropene; 1,3-dichloropropylene
        Diethyl phthalate
        2,4-Dimethylphenol; 2,4-xylenol
        Dimethyl phthalate
        4,6-Dinitro-o-cresol; 2-methyl-4,6-dinitrophenol
        2,4-Dinitrophenol
        2,4-Dinitrotoluene
        2,6-Dinitrotoluene
        Dioctyl phthalate; di-n-octyl phthalate
        1,2-Diphenylhydrazine
        Endosulfan; thiodan
        alpha-Endosulfan
        beta-Endosulfan
        Endosulfan sulfate
        Endrin
        Endrin aldehyde
        Ethylbenzene
        Fluoranthene
        Fluorene; 9H-fluorene
        Fluoride
        Guthion
        Heptachlor
        Heptachlor epoxide
        Hexachlorocyclopentadiene
        Hexachloroethane
        Indeno[1,2,3-cd]pyrene; 2,3-o-phenylene pyrene
        Isophorone
        Lead
        Malathion
        Methoxychlor
        Methyl bromide; bromomethane
        Methyl chloride; chloromethane
        Methylene chloride; dichloromethane
        Napthalene
        Nickel
        Nitrobenzene
        2-Nitrophenol
        4-Nitrophenol
        N-Nitrosodimethylamine
        N-Nitrosodiphenylamine
        N-Nitrosodipropylamine; N-nitrosodi-n-propylamine
        Parathion
        Pentachlorophenol
        Phenanthrene
        Phenol
        Iron
        Pyrene
        Selenium
        Silver
        1,1,2,2-Tetrachloroethane
        Tetrachloroethylene
        Thallium
        Toluene; methylbenzene
        1,2,4-Trichlorobenzene
        1,1,1-Trichloroethane
        1,1,2-Trichloroethane
        Trichloroethylene; trichloroethene
        2,4,6-Trichlorophenol
        Vinyl chloride; chloroethylene; chloroethene
        Zinc
    
    Appendix A to part 132--Great Lakes Water Quality Initiative 
    Methodologies for Developments of Aquatic Life Criteria and Values
    
    Methodology for Deriving Aquatic Life Criteria: Tier I
    
        Great Lakes States and Tribes shall adopt provisions consistent 
    with (as protective as) this appendix. [[Page 15394]] 
    
    I. Definitions
    
        A. Material of Concern. When defining the material of concern 
    the following should be considered:
        1. Each separate chemical that does not ionize substantially in 
    most natural bodies of water should usually be considered a separate 
    material, except possibly for structurally similar organic compounds 
    that only exist in large quantities as commercial mixtures of the 
    various compounds and apparently have similar biological, chemical, 
    physical, and toxicological properties.
        2. For chemicals that ionize substantially in most natural 
    bodies of water (e.g., some phenols and organic acids, some salts of 
    phenols and organic acids, and most inorganic salts and coordination 
    complexes of metals and metalloid), all forms that would be in 
    chemical equilibrium should usually be considered one material. Each 
    different oxidation state of a metal and each different non-
    ionizable covalently bonded organometallic compound should usually 
    be considered a separate material.
        3. The definition of the material of concern should include an 
    operational analytical component. Identification of a material 
    simply as ``sodium,'' for example, implies ``total sodium,'' but 
    leaves room for doubt. If ``total'' is meant, it must be explicitly 
    stated. Even ``total'' has different operational definitions, some 
    of which do not necessarily measure ``all that is there'' in all 
    samples. Thus, it is also necessary to reference or describe the 
    analytical method that is intended. The selection of the operational 
    analytical component should take into account the analytical and 
    environmental chemistry of the material and various practical 
    considerations, such as labor and equipment requirements, and 
    whether the method would require measurement in the field or would 
    allow measurement after samples are transported to a laboratory.
        a. The primary requirements of the operational analytical 
    component are that it be appropriate for use on samples of receiving 
    water, that it be compatible with the available toxicity and 
    bioaccumulation data without making extrapolations that are too 
    hypothetical, and that it rarely result in underprotection or 
    overprotection of aquatic organisms and their uses. Toxicity is the 
    property of a material, or combination of materials, to adversely 
    affect organisms.
        b. Because an ideal analytical measurement will rarely be 
    available, an appropriate compromise measurement will usually have 
    to be used. This compromise measurement must fit with the general 
    approach that if an ambient concentration is lower than the 
    criterion, unacceptable effects will probably not occur, i.e., the 
    compromise measure must not err on the side of underprotection when 
    measurements are made on a surface water. What is an appropriate 
    measurement in one situation might not be appropriate for another. 
    For example, because the chemical and physical properties of an 
    effluent are usually quite different from those of the receiving 
    water, an analytical method that is appropriate for analyzing an 
    effluent might not be appropriate for expressing a criterion, and 
    vice versa. A criterion should be based on an appropriate analytical 
    measurement, but the criterion is not rendered useless if an ideal 
    measurement either is not available or is not feasible.
        Note: The analytical chemistry of the material might have to be 
    taken into account when defining the material or when judging the 
    acceptability of some toxicity tests, but a criterion must not be 
    based on the sensitivity of an analytical method. When aquatic 
    organisms are more sensitive than routine analytical methods, the 
    proper solution is to develop better analytical methods.
        4. It is now the policy of EPA that the use of dissolved metal 
    to set and measure compliance with water quality standards is the 
    recommended approach, because dissolved metal more closely 
    approximates the bioavailable fraction of metal in the water column 
    that does total recoverable metal. One reason is that a primary 
    mechanism for water column toxicity is adsorption at the gill 
    surface which requires metals to be in the dissolved form. Reasons 
    for the consideration of total recoverable metals criteria include 
    risk management considerations not covered by evaluation of water 
    column toxicity. A risk manager may consider sediments and food 
    chain effects and may decide to take a conservative approach for 
    metals, considering that metals are very persistent chemicals. This 
    approach could include the use of total recoverable metal in water 
    quality standards. A range of different risk management decisions 
    can be justified. EPA recommends that State water quality standards 
    be based on dissolved metal. EPA will also approve a State risk 
    management decision to adopt standards based on total recoverable 
    metal, if those standards are otherwise approvable under this 
    program.
        B. Acute Toxicity. Concurrent and delayed adverse effect(s) that 
    results from an acute exposure and occurs within any short 
    observation period which begins when the exposure begins, may extend 
    beyond the exposure period, and usually does not constitute a 
    substantial portion of the life span of the organism. (Concurrent 
    toxicity is an adverse effect to an organism that results from, and 
    occurs during, its exposure to one or more test materials.) Exposure 
    constitutes contact with a chemical or physical agent. Acute 
    exposure, however, is exposure of an organism for any short period 
    which usually does not constitute a substantial portion of its life 
    span.
        C. Chronic Toxicity. Concurrent and delayed adverse effect(s) 
    that occurs only as a result of a chronic exposure. Chronic exposure 
    is exposure of an organism for any long period or for a substantial 
    portion of its life span.
    
    II. Collection of Data
    
        A. Collect all data available on the material concerning 
    toxicity to aquatic animals and plants.
        B. All data that are used should be available in typed, dated, 
    and signed hard copy (e.g., publication, manuscript, letter, 
    memorandum, etc.) with enough supporting information to indicate 
    that acceptable test procedures were used and that the results are 
    reliable. In some cases, it might be appropriate to obtain written 
    information from the investigator, if possible. Information that is 
    not available for distribution shall not be used.
        C. Questionable data, whether published or unpublished, must not 
    be used. For example, data must be rejected if they are from tests 
    that did not contain a control treatment, tests in which too many 
    organisms in the control treatment died or showed signs of stress or 
    disease, and tests in which distilled or deionized water was used as 
    the dilution water without the addition of appropriate salts.
        D. Data on technical grade materials may be used if appropriate, 
    but data on formulated mixtures and emulsifiable concentrates of the 
    material must not be used.
        E. For some highly volatile, hydrolyzable, or degradable 
    materials, it might be appropriate to use only results of flow-
    through tests in which the concentrations of test material in test 
    solutions were measured using acceptable analytical methods. A flow-
    through test is a test with aquatic organisms in which test 
    solutions flow into constant-volume test chambers either 
    intermittently (e.g., every few minutes) or continuously, with the 
    excess flowing out.
        F. Data must be rejected if obtained using:
        1. Brine shrimp, because they usually only occur naturally in 
    water with salinity greater than 35 g/kg.
        2. Species that do not have reproducing wild populations in 
    North America.
        3. Organisms that were previously exposed to substantial 
    concentrations of the test material or other contaminants.
        4. Saltwater species except for use in deriving acute-chronic 
    ratios. An ACR is a standard measure of the acute toxicity of a 
    material divided by an appropriate measure of the chronic toxicity 
    of the same material under comparable conditions.
        G. Questionable data, data on formulated mixtures and 
    emulsifiable concentrates, and data obtained with species non-
    resident to North America or previously exposed organisms may be 
    used to provide auxiliary information but must not be used in the 
    derivation of criteria.
    
    III. Required Data
    
        A. Certain data should be available to help ensure that each of 
    the major kinds of possible adverse effects receives adequate 
    consideration. An adverse effect is a change in an organism that is 
    harmful to the organism. Exposure means contact with a chemical or 
    physical agent. Results of acute and chronic toxicity tests with 
    representative species of aquatic animals are necessary so that data 
    available for tested species can be considered a useful indication 
    of the sensitivities of appropriate untested species. Fewer data 
    concerning toxicity to aquatic plants are usually available because 
    procedures for conducting tests with plants and interpreting the 
    results of such tests are not as well developed.
        B. To derive a Great Lakes Tier I criterion for aquatic 
    organisms and their uses, the following must be available:
        1. Results of acceptable acute (or chronic) tests (see section 
    IV or VI of this appendix) with at least one species of freshwater 
    animal in at least eight different families such that all of the 
    following are included: [[Page 15395]] 
        a. The family Salmonidae in the class Osteichthyes;
        b. One other family (preferably a commercially or recreationally 
    important, warmwater species) in the class Osteichthyes (e.g., 
    bluegill, channel catfish);
        c. A third family in the phylum Chordata (e.g., fish, 
    amphibian);
        d. A planktonic crustacean (e.g., a cladoceran, copepod);
        e. A benthic crustacean (e.g., ostracod, isopod, amphipod, 
    crayfish);
        f. An insect (e.g., mayfly, dragonfly, damselfly, stonefly, 
    caddisfly, mosquito, midge);
        g. A family in a phylum other than Arthropoda or Chordata (e.g., 
    Rotifera, Annelida, Mollusca);
        h. A family in any order of insect or any phylum not already 
    represented.
        2. Acute-chronic ratios (see section VI of this appendix) with 
    at least one species of aquatic animal in at least three different 
    families provided that of the three species:
        a. At least one is a fish;
        b. At least one is an invertebrate; and
        c. At least one species is an acutely sensitive freshwater 
    species (the other two may be saltwater species).
        3. Results of at least one acceptable test with a freshwater 
    algae or vascular plant is desirable but not required for criterion 
    derivation (see section VIII of this appendix). If plants are among 
    the aquatic organisms most sensitive to the material, results of a 
    test with a plant in another phylum (division) should also be 
    available.
        C. If all required data are available, a numerical criterion can 
    usually be derived except in special cases. For example, derivation 
    of a chronic criterion might not be possible if the available ACRs 
    vary by more than a factor of ten with no apparent pattern. Also, if 
    a criterion is to be related to a water quality characteristic (see 
    sections V and VII of this appendix), more data will be required.
        D. Confidence in a criterion usually increases as the amount of 
    available pertinent information increases. Thus, additional data are 
    usually desirable.
    
    IV. Final Acute Value
    
        A. Appropriate measures of the acute (short-term) toxicity of 
    the material to a variety of species of aquatic animals are used to 
    calculate the Final Acute Value (FAV). The calculated Final Acute 
    Value is a calculated estimate of the concentration of a test 
    material such that 95 percent of the genera (with which acceptable 
    acute toxicity tests have been conducted on the material) have 
    higher Genus Mean Acute Values (GMAVs). An acute test is a 
    comparative study in which organisms, that are subjected to 
    different treatments, are observed for a short period usually not 
    constituting a substantial portion of their life span. However, in 
    some cases, the Species Mean Acute Value (SMAV) of a commercially or 
    recreationally important species of the Great Lakes System is lower 
    than the calculated FAV, then the SMAV replaces the calculated FAV 
    in order to provide protection for that important species.
        B. Acute toxicity tests shall be conducted using acceptable 
    procedures. For good examples of acceptable procedures see American 
    Society for Testing and Materials (ASTM) Standard E 729, Guide for 
    Conducting Acute Toxicity Tests with Fishes, Macroinvertebrates, and 
    Amphibians.
        C. Except for results with saltwater annelids and mysids, 
    results of acute tests during which the test organisms were fed 
    should not be used, unless data indicate that the food did not 
    affect the toxicity of the test material. (Note: If the minimum 
    acute-chronic ratio data requirements (as described in section 
    III.B.2 of this appendix) are not met with freshwater data alone, 
    saltwater data may be used.)
        D. Results of acute tests conducted in unusual dilution water, 
    e.g., dilution water in which total organic carbon or particulate 
    matter exceeded five mg/L, should not be used, unless a relationship 
    is developed between acute toxicity and organic carbon or 
    particulate matter, or unless data show that organic carbon or 
    particulate matter, etc., do not affect toxicity.
        E. Acute values must be based upon endpoints which reflect the 
    total severe adverse impact of the test material on the organisms 
    used in the test. Therefore, only the following kinds of data on 
    acute toxicity to aquatic animals shall be used:
        1. Tests with daphnids and other cladocerans must be started 
    with organisms less than 24 hours old and tests with midges must be 
    started with second or third instar larvae. It is preferred that the 
    results should be the 48-hour EC50 based on the total percentage of 
    organisms killed and immobilized. If such an EC50 is not available 
    for a test, the 48-hour LC50 should be used in place of the desired 
    48-hour EC50. An EC50 or LC50 of longer than 48 hours can be used as 
    long as the animals were not fed and the control animals were 
    acceptable at the end of the test. An EC50 is a statistically or 
    graphically estimated concentration that is expected to cause one or 
    more specified effects in 50% of a group of organisms under 
    specified conditions. An LC50 is a statistically or graphically 
    estimated concentration that is expected to be lethal to 50% of a 
    group of organisms under specified conditions.
        2. It is preferred that the results of a test with embryos and 
    larvae of barnacles, bivalve molluscs (clams, mussels, oysters and 
    scallops), sea urchins, lobsters, crabs, shrimp and abalones be the 
    96-hour EC50 based on the percentage of organisms with incompletely 
    developed shells plus the percentage of organisms killed. If such an 
    EC50 is not available from a test, of the values that are available 
    from the test, the lowest of the following should be used in place 
    of the desired 96-hour EC50: 48- to 96-hour EC50s based on 
    percentage of organisms with incompletely developed shells plus 
    percentage of organisms killed, 48- to 96-hour EC50s based upon 
    percentage of organisms with incompletely developed shells, and 48-
    hour to 96-hour LC50s. (Note: If the minimum acute-chronic ratio 
    data requirements (as described in section III.B.2 of this appendix) 
    are not met with freshwater data alone, saltwater data may be used.)
        3. It is preferred that the result of tests with all other 
    aquatic animal species and older life stages of barnacles, bivalve 
    molluscs (clams, mussels, oysters and scallops), sea urchins, 
    lobsters, crabs, shrimp and abalones be the 96-hour EC50 based on 
    percentage of organisms exhibiting loss of equilibrium plus 
    percentage of organisms immobilized plus percentage of organisms 
    killed. If such an EC50 is not available from a test, of the values 
    that are available from a test the lower of the following should be 
    used in place of the desired 96-hour EC50: the 96-hour EC50 based on 
    percentage of organisms exhibiting loss of equilibrium plus 
    percentage of organisms immobilized and the 96-hour LC50.
        4. Tests whose results take into account the number of young 
    produced, such as most tests with protozoans, are not considered 
    acute tests, even if the duration was 96 hours or less.
        5. If the tests were conducted properly, acute values reported 
    as ``greater than'' values and those which are above the solubility 
    of the test material should be used, because rejection of such acute 
    values would bias the Final Acute Value by eliminating acute values 
    for resistant species.
        F. If the acute toxicity of the material to aquatic animals has 
    been shown to be related to a water quality characteristic such as 
    hardness or particulate matter for freshwater animals, refer to 
    section V of this appendix.
        G. The agreement of the data within and between species must be 
    considered. Acute values that appear to be questionable in 
    comparison with other acute and chronic data for the same species 
    and for other species in the same genus must not be used. For 
    example, if the acute values available for a species or genus differ 
    by more than a factor of 10, rejection of some or all of the values 
    would be appropriate, absent countervailing circumstances.
        H. If the available data indicate that one or more life stages 
    are at least a factor of two more resistant than one or more other 
    life stages of the same species, the data for the more resistant 
    life stages must not be used in the calculation of the SMAV because 
    a species cannot be considered protected from acute toxicity if all 
    of the life stages are not protected.
        I. For each species for which at least one acute value is 
    available, the SMAV shall be calculated as the geometric mean of the 
    results of all acceptable flow-through acute toxicity tests in which 
    the concentrations of test material were measured with the most 
    sensitive tested life stage of the species. For a species for which 
    no such result is available, the SMAV shall be calculated as the 
    geometric mean of all acceptable acute toxicity tests with the most 
    sensitive tested life stage, i.e., results of flow-through tests in 
    which the concentrations were not measured and results of static and 
    renewal tests based on initial concentrations (nominal 
    concentrations are acceptable for most test materials if measured 
    concentrations are not available) of test material. A renewal test 
    is a test with aquatic organisms in which either the test solution 
    in a test chamber is removed and replaced at least once during the 
    test or the test organisms are transferred into a new test solution 
    of the same composition at least once during the test. A static test 
    is a test with aquatic organisms in which the solution 
    [[Page 15396]] and organisms that are in a test chamber at the 
    beginning of the test remain in the chamber until the end of the 
    test, except for removal of dead test organisms.
    
        Note 1: Data reported by original investigators must not be 
    rounded off. Results of all intermediate calculations must not be 
    rounded off to fewer than four significant digits.
    
        Note 2: The geometric mean of N numbers is the Nth root of the 
    product of the N numbers. Alternatively, the geometric mean can be 
    calculated by adding the logarithms of the N numbers, dividing the 
    sum by N, and taking the antilog of the quotient. The geometric mean 
    of two numbers is the square root of the product of the two numbers, 
    and the geometric mean of one number is that number. Either natural 
    (base e) or common (base 10) logarithms can be used to calculate 
    geometric means as long as they are used consistently within each 
    set of data, i.e., the antilog used must match the logarithms used.
    
        Note 3: Geometric means, rather than arithmetic means, are used 
    here because the distributions of sensitivities of individual 
    organisms in toxicity tests on most materials and the distributions 
    of sensitivities of species within a genus are more likely to be 
    lognormal than normal. Similarly, geometric means are used for ACRs 
    because quotients are likely to be closer to lognormal than normal 
    distributions. In addition, division of the geometric mean of a set 
    of numerators by the geometric mean of the set of denominators will 
    result in the geometric mean of the set of corresponding quotients.
    
        J. For each genus for which one or more SMAVs are available, the 
    GMAV shall be calculated as the geometric mean of the SMAVs 
    available for the genus.
        K. Order the GMAVs from high to low.
        L. Assign ranks, R, to the GMAVs from ``1'' for the lowest to 
    ``N'' for the highest. If two or more GMAVs are identical, assign 
    them successive ranks.
        M. Calculate the cumulative probability, P, for each GMAV as R/
    (N+1).
        N. Select the four GMAVs which have cumulative probabilities 
    closest to 0.05 (if there are fewer than 59 GMAVs, these will always 
    be the four lowest GMAVs).
        O. Using the four selected GMAVs, and Ps, calculate
    [GRAPHIC][TIFF OMITTED]TR23MR95.104
    
    
        Note: Natural logarithms (logarithms to base e, denoted as ln) 
    are used herein merely because they are easier to use on some hand 
    calculators and computers than common (base 10) logarithms. 
    Consistent use of either will produce the same result.
    
        P. If for a commercially or recreationally important species of 
    the Great Lakes System the geometric mean of the acute values from 
    flow-through tests in which the concentrations of test material were 
    measured is lower than the calculated Final Acute Value (FAV), then 
    that geometric mean must be used as the FAV instead of the 
    calculated FAV.
        Q. See section VI of this appendix.
    
    V. Final Acute Equation
    
        A. When enough data are available to show that acute toxicity to 
    two or more species is similarly related to a water quality 
    characteristic, the relationship shall be taken into account as 
    described in sections V.B through V.G of this appendix or using 
    analysis of covariance. The two methods are equivalent and produce 
    identical results. The manual method described below provides an 
    understanding of this application of covariance analysis, but 
    computerized versions of covariance analysis are much more 
    convenient for analyzing large data sets. If two or more factors 
    affect toxicity, multiple regression analysis shall be used.
        B. For each species for which comparable acute toxicity values 
    are available at two or more different values of the water quality 
    characteristic, perform a least squares regression of the acute 
    toxicity values on the corresponding values of the water quality 
    characteristic to obtain the slope and its 95 percent confidence 
    limits for each species.
    
        Note: Because the best documented relationship is that between 
    hardness and acute toxicity of metals in fresh water and a log-log 
    relationship fits these data, geometric means and natural logarithms 
    of both toxicity and water quality are used in the rest of this 
    section. For relationships based on other water quality 
    characteristics, such as Ph, temperature, no transformation or a 
    different transformation might fit the data better, and appropriate 
    changes will be necessary throughout this section.
    
        C. Decide whether the data for each species are relevant, taking 
    into account the range and number of the tested values of the water 
    quality characteristic and the degree of agreement within and 
    between species. For example, a slope based on six data points might 
    be of limited value if it is based only on data for a very narrow 
    range of values of the water quality characteristic. A slope based 
    on only two data points, however, might be useful if it is 
    consistent with other information and if the two points cover a 
    broad enough range of the water quality characteristic. In addition, 
    acute values that appear to be questionable in comparison with other 
    acute and chronic data available for the same species and for other 
    species in the same genus should not be used. For example, if after 
    adjustment for the water quality characteristic, the acute values 
    available for a species or genus differ by more than a factor of 10, 
    rejection of some or all of the values would be appropriate, absent 
    countervailing justification. If useful slopes are not available for 
    at least one fish and one invertebrate or if the available slopes 
    are too dissimilar or if too few data are available to adequately 
    define the relationship between acute toxicity and the water quality 
    characteristic, return to section IV.G of this appendix, using the 
    results of tests conducted under conditions and in waters similar to 
    those commonly used for toxicity tests with the species.
        D. For each species, calculate the geometric mean of the 
    available acute values and then divide each of the acute values for 
    the species by the geometric mean for the species. This normalizes 
    the acute values so that the geometric mean of the normalized values 
    for each species individually and for any combination of species is 
    1.0.
        E. Similarly normalize the values of the water quality 
    characteristic for each species individually using the same 
    procedure as above.
        F. Individually for each species perform a least squares 
    regression of the normalized [[Page 15397]] acute values of the 
    water quality characteristic. The resulting slopes and 95 percent 
    confidence limits will be identical to those obtained in section 
    V.B. of this appendix. If, however, the data are actually plotted, 
    the line of best fit for each individual species will go through the 
    point 1,1 in the center of the graph.
        G. Treat all of the normalized data as if they were all for the 
    same species and perform a least squares regression of all of the 
    normalized acute values on the corresponding normalized values of 
    the water quality characteristic to obtain the pooled acute slope, 
    V, and its 95 percent confidence limits. If all of the normalized 
    data are actually plotted, the line of best fit will go through the 
    point 1,1 in the center of the graph.
        H. For each species calculate the geometric mean, W, of the 
    acute toxicity values and the geometric mean, X, of the values of 
    the water quality characteristic. (These were calculated in sections 
    V.D and V.E of this appendix).
        I. For each species, calculate the logarithm, Y, of the SMAV at 
    a selected value, Z, of the water quality characteristic using the 
    equation:
    
    Y=ln W-V(ln X-ln Z)
    
        J. For each species calculate the SMAV at X using the equation:
    
    SMAV=eY
    
        Note: Alternatively, the SMAVs at Z can be obtained by skipping 
    step H above, using the equations in steps I and J to adjust each 
    acute value individually to Z, and then calculating the geometric 
    mean of the adjusted values for each species individually. This 
    alternative procedure allows an examination of the range of the 
    adjusted acute values for each species.
    
        K. Obtain the FAV at Z by using the procedure described in 
    sections IV.J through IV.O of this appendix.
        L. If, for a commercially or recreationally important species of 
    the Great Lakes System the geometric mean of the acute values at Z 
    from flow-through tests in which the concentrations of the test 
    material were measured is lower than the FAV at Z, then the 
    geometric mean must be used as the FAV instead of the FAV.
        M. The Final Acute Equation is written as:
    
    FAV=e(V[ln(water quality characteristic)]+A-V[ln Z]),
    
        where:
    V=pooled acute slope, and A=ln(FAV at Z).
    
        Because V, A, and Z are known, the FAV can be calculated for any 
    selected value of the water quality characteristic.
    
    VI. Final Chronic Value
    
        A. Depending on the data that are available concerning chronic 
    toxicity to aquatic animals, the Final Chronic Value (FCV) can be 
    calculated in the same manner as the FAV or by dividing the FAV by 
    the Final Acute-Chronic Ratio (FACR). In some cases, it might not be 
    possible to calculate a FCV. The FCV is (a) a calculated estimate of 
    the concentration of a test material such that 95 percent of the 
    genera (with which acceptable chronic toxicity tests have been 
    conducted on the material) have higher GMCVs, or (b) the quotient of 
    an FAV divided by an appropriate ACR, or (c) the SMCV of an 
    important and/or critical species, if the SMCV is lower than the 
    calculated estimate or the quotient, whichever is applicable.
    
        Note: As the name implies, the ACR is a way of relating acute 
    and chronic toxicities.
    
        B. Chronic values shall be based on results of flow-through 
    (except renewal is acceptable for daphnids) chronic tests in which 
    the concentrations of test material in the test solutions were 
    properly measured at appropriate times during the test. A chronic 
    test is a comparative study in which organisms, that are subjected 
    to different treatments, are observed for a long period or a 
    substantial portion of their life span.
        C. Results of chronic tests in which survival, growth, or 
    reproduction in the control treatment was unacceptably low shall not 
    be used. The limits of acceptability will depend on the species.
        D. Results of chronic tests conducted in unusual dilution water, 
    e.g., dilution water in which total organic carbon or particulate 
    matter exceeded five mg/L, should not be used, unless a relationship 
    is developed between chronic toxicity and organic carbon or 
    particulate matter, or unless data show that organic carbon, 
    particulate matter, etc., do not affect toxicity.
        E. Chronic values must be based on endpoints and lengths of 
    exposure appropriate to the species. Therefore, only results of the 
    following kinds of chronic toxicity tests shall be used:
        1. Life-cycle toxicity tests consisting of exposures of each of 
    two or more groups of individuals of a species to a different 
    concentration of the test material throughout a life cycle. To 
    ensure that all life stages and life processes are exposed, tests 
    with fish should begin with embryos or newly hatched young less than 
    48 hours old, continue through maturation and reproduction, and 
    should end not less than 24 days (90 days for salmonids) after the 
    hatching of the next generation. Tests with daphnids should begin 
    with young less than 24 hours old and last for not less than 21 
    days, and for ceriodaphnids not less than seven days. For good 
    examples of acceptable procedures see American Society for Testing 
    and Materials (ASTM) Standard E 1193 Guide for conducting renewal 
    life-cycle toxicity tests with Daphnia magna and ASTM Standard E 
    1295 Guide for conducting three-brood, renewal toxicity tests with 
    Ceriodaphnia dubia. Tests with mysids should begin with young less 
    than 24 hours old and continue until seven days past the median time 
    of first brood release in the controls. For fish, data should be 
    obtained and analyzed on survival and growth of adults and young, 
    maturation of males and females, eggs spawned per female, embryo 
    viability (salmonids only), and hatchability. For daphnids, data 
    should be obtained and analyzed on survival and young per female. 
    For mysids, data should be obtained and analyzed on survival, 
    growth, and young per female.
        2. Partial life-cycle toxicity tests consist of exposures of 
    each of two more groups of individuals of a species of fish to a 
    different concentration of the test material through most portions 
    of a life cycle. Partial life-cycle tests are allowed with fish 
    species that require more than a year to reach sexual maturity, so 
    that all major life stages can be exposed to the test material in 
    less than 15 months. A life-cycle test is a comparative study in 
    which organisms, that are subjected to different treatments, are 
    observed at least from a life stage in one generation to the same 
    life-stage in the next generation. Exposure to the test material 
    should begin with immature juveniles at least two months prior to 
    active gonad development, continue through maturation and 
    reproduction, and end not less than 24 days (90 days for salmonids) 
    after the hatching of the next generation. Data should be obtained 
    and analyzed on survival and growth of adults and young, maturation 
    of males and females, eggs spawned per female, embryo viability 
    (salmonids only), and hatchability.
        3. Early life-stage toxicity tests consisting of 28- to 32-day 
    (60 days post hatch for salmonids) exposures of the early life 
    stages of a species of fish from shortly after fertilization through 
    embryonic, larval, and early juvenile development. Data should be 
    obtained and analyzed on survival and growth.
        Note: Results of an early life-stage test are used as 
    predictions of results of life-cycle and partial life-cycle tests 
    with the same species. Therefore, when results of a life-cycle or 
    partial life-cycle test are available, results of an early life-
    stage test with the same species should not be used. Also, results 
    of early life-stage tests in which the incidence of mortalities or 
    abnormalities increased substantially near the end of the test shall 
    not be used because the results of such tests are possibly not good 
    predictions of comparable life-cycle or partial life-cycle tests.
        F. A chronic value may be obtained by calculating the geometric 
    mean of the lower and upper chronic limits from a chronic test or by 
    analyzing chronic data using regression analysis.
        1. A lower chronic limit is the highest tested concentration:
        a. In an acceptable chronic test;
        b. Which did not cause an unacceptable amount of adverse effect 
    on any of the specified biological measurements; and
        c. Below which no tested concentration caused an unacceptable 
    effect.
        2. An upper chronic limit is the lowest tested concentration:
        a. In an acceptable chronic test;
        b. Which did cause an unacceptable amount of adverse effect on 
    one or more of the specified biological measurements; and,
        c. Above which all tested concentrations also caused such an 
    effect.
        Note: Because various authors have used a variety of terms and 
    definitions to interpret and report results of chronic tests, 
    reported results should be reviewed carefully. The amount of effect 
    that is considered unacceptable is often based on a statistical 
    hypothesis test, but might also be defined in terms of a specified 
    percent reduction from the controls. A small percent reduction 
    (e.g., three percent) might be considered acceptable even if it is 
    statistically significantly different from the control, whereas a 
    large percent reduction (e.g., 30 percent) might be considered 
    unacceptable even if it is not statistically significant.
        G. If the chronic toxicity of the material to aquatic animals 
    has been shown to be related [[Page 15398]] to a water quality 
    characteristic such as hardness or particulate matter for freshwater 
    animals, refer to section VII of this appendix.
        H. If chronic values are available for species in eight families 
    as described in section III.B.1 of this appendix, a SMCV shall be 
    calculated for each species for which at least one chronic value is 
    available by calculating the geometric mean of the results of all 
    acceptable life-cycle and partial life-cycle toxicity tests with the 
    species; for a species of fish for which no such result is 
    available, the SMCV is the geometric mean of all acceptable early 
    life-stage tests. Appropriate GMCVs shall also be calculated. A GMCV 
    is the geometric mean of the SMCVs for the genus. The FCV shall be 
    obtained using the procedure described in sections IV.J through IV.O 
    of this appendix, substituting SMCV and GMCV for SMAV and GMAV 
    respectively. See section VI.M of this appendix.
        Note: Section VI.I through VI.L are for use when chronic values 
    are not available for species in eight taxonomic families as 
    described in section III.B.1 of this appendix.
        I. For each chronic value for which at least one corresponding 
    appropriate acute value is available, calculate an ACR, using for 
    the numerator the geometric mean of the results of all acceptable 
    flow-through (except static is acceptable for daphnids and midges) 
    acute tests in the same dilution water in which the concentrations 
    are measured. For fish, the acute test(s) should be conducted with 
    juveniles. The acute test(s) should be part of the same study as the 
    chronic test. If acute tests were not conducted as part of the same 
    study, but were conducted as part of a different study in the same 
    laboratory and dilution water, then they may be used. If no such 
    acute tests are available, results of acute tests conducted in the 
    same dilution water in a different laboratory may be used. If no 
    such acute tests are available, an ACR shall not be calculated.
        J. For each species, calculate the SMACR as the geometric mean 
    of all ACRs available for that species. If the minimum ACR data 
    requirements (as described in section III.B.2 of this appendix) are 
    not met with freshwater data alone, saltwater data may be used along 
    with the freshwater data.
        K. For some materials, the ACR seems to be the same for all 
    species, but for other materials the ratio seems to increase or 
    decrease as the SMAV increases. Thus the FACR can be obtained in 
    three ways, depending on the data available:
        1. If the species mean ACR seems to increase or decrease as the 
    SMAVs increase, the FACR shall be calculated as the geometric mean 
    of the ACRs for species whose SMAVs are close to the FAV.
        2. If no major trend is apparent and the ACRs for all species 
    are within a factor of ten, the FACR shall be calculated as the 
    geometric mean of all of the SMACRs.
        3. If the most appropriate SMACRs are less than 2.0, and 
    especially if they are less than 1.0, acclimation has probably 
    occurred during the chronic test. In this situation, because 
    continuous exposure and acclimation cannot be assured to provide 
    adequate protection in field situations, the FACR should be assumed 
    to be two, so that the FCV is equal to the Criterion Maximum 
    Concentration (CMC). (See section X.B of this appendix.)
        If the available SMACRs do not fit one of these cases, a FACR 
    may not be obtained and a Tier I FCV probably cannot be calculated.
        L. Calculate the FCV by dividing the FAV by the FACR.
        FCV=FAVFACR
    If there is a Final Acute Equation rather than a FAV, see also 
    section V of this appendix.
        M. If the SMCV of a commercially or recreationally important 
    species of the Great Lakes System is lower than the calculated FCV, 
    then that SMCV must be used as the FCV instead of the calculated 
    FCV.
        N. See section VIII of this appendix.
    
    VII. Final Chronic Equation
    
        A. A Final Chronic Equation can be derived in two ways. The 
    procedure described in section VII.A of this appendix will result in 
    the chronic slope being the same as the acute slope. The procedure 
    described in sections VII.B through N of this appendix will usually 
    result in the chronic slope being different from the acute slope.
        1. If ACRs are available for enough species at enough values of 
    the water quality characteristic to indicate that the ACR appears to 
    be the same for all species and appears to be independent of the 
    water quality characteristic, calculate the FACR as the geometric 
    mean of the available SMACRs.
        2. Calculate the FCV at the selected value Z of the water 
    quality characteristic by dividing the FAV at Z (see section V.M of 
    this appendix) by the FACR.
        3. Use V=pooled acute slope (see section V.M of this appendix), 
    and
        L=pooled chronic slope.
        4. See section VII.M of this appendix.
        B. When enough data are available to show that chronic toxicity 
    to at least one species is related to a water quality 
    characteristic, the relationship should be taken into account as 
    described in sections C through G below or using analysis of 
    covariance. The two methods are equivalent and produce identical 
    results. The manual method described below provides an understanding 
    of this application of covariance analysis, but computerized 
    versions of covariance analysis are much more convenient for 
    analyzing large data sets. If two or more factors affect toxicity, 
    multiple regression analysis shall be used.
        C. For each species for which comparable chronic toxicity values 
    are available at two or more different values of the water quality 
    characteristic, perform a least squares regression of the chronic 
    toxicity values on the corresponding values of the water quality 
    characteristic to obtain the slope and its 95 percent confidence 
    limits for each species.
    
        Note: Because the best documented relationship is that between 
    hardness and acute toxicity of metals in fresh water and a log-log 
    relationship fits these data, geometric means and natural logarithms 
    of both toxicity and water quality are used in the rest of this 
    section. For relationships based on other water quality 
    characteristics, such as Ph, temperature, no transformation or a 
    different transformation might fit the data better, and appropriate 
    changes will be necessary throughout this section. It is probably 
    preferable, but not necessary, to use the same transformation that 
    was used with the acute values in section V of this appendix.
    
        D. Decide whether the data for each species are relevant, taking 
    into account the range and number of the tested values of the water 
    quality characteristic and the degree of agreement within and 
    between species. For example, a slope based on six data points might 
    be of limited value if it is based only on data for a very narrow 
    range of values of the water quality characteristic. A slope based 
    on only two data points, however, might be more useful if it is 
    consistent with other information and if the two points cover a 
    broad range of the water quality characteristic. In addition, 
    chronic values that appear to be questionable in comparison with 
    other acute and chronic data available for the same species and for 
    other species in the same genus in most cases should not be used. 
    For example, if after adjustment for the water quality 
    characteristic, the chronic values available for a species or genus 
    differ by more than a factor of 10, rejection of some or all of the 
    values is, in most cases, absent countervailing circumstances, 
    appropriate. If a useful chronic slope is not available for at least 
    one species or if the available slopes are too dissimilar or if too 
    few data are available to adequately define the relationship between 
    chronic toxicity and the water quality characteristic, it might be 
    appropriate to assume that the chronic slope is the same as the 
    acute slope, which is equivalent to assuming that the ACR is 
    independent of the water quality characteristic. Alternatively, 
    return to section VI.H of this appendix, using the results of tests 
    conducted under conditions and in waters similar to those commonly 
    used for toxicity tests with the species.
        E. Individually for each species, calculate the geometric mean 
    of the available chronic values and then divide each chronic value 
    for a species by the mean for the species. This normalizes the 
    chronic values so that the geometric mean of the normalized values 
    for each species individually, and for any combination of species, 
    is 1.0.
        F. Similarly, normalize the values of the water quality 
    characteristic for each species individually.
        G. Individually for each species, perform a least squares 
    regression of the normalized chronic toxicity values on the 
    corresponding normalized values of the water quality characteristic. 
    The resulting slopes and the 95 percent confidence limits will be 
    identical to those obtained in section VII.B of this appendix. Now, 
    however, if the data are actually plotted, the line of best fit for 
    each individual species will go through the point 1,1 in the center 
    of the graph.
        H. Treat all of the normalized data as if they were all the same 
    species and perform a least squares regression of all of the 
    normalized chronic values on the corresponding normalized values of 
    the water quality characteristic to obtain the pooled chronic slope, 
    L, and its 95 percent confidence limits.
        If all normalized data are actually plotted, the line of best 
    fit will go through the point 1,1 in the center of the 
    graph. [[Page 15399]] 
        I. For each species, calculate the geometric mean, M, of the 
    toxicity values and the geometric mean, P, of the values of the 
    water quality characteristic. (These are calculated in sections 
    VII.E and F of this appendix.)
        J. For each species, calculate the logarithm, Q, of the SMCV at 
    a selected value, Z, of the water quality characteristic using the 
    equation:
    
    Q=ln M--L(ln P-ln Z)
    
        Note: Although it is not necessary, it is recommended that the 
    same value of the water quality characteristic be used here as was 
    used in section V of this appendix.
    
        K. For each species, calculate a SMCV at Z using the equation:
    
    SMCV=eQ
    
        Note: Alternatively, the SMCV at Z can be obtained by skipping 
    section VII.J of this appendix, using the equations in sections 
    VII.J and K of this appendix to adjust each chronic value 
    individually to Z, and then calculating the geometric means of the 
    adjusted values for each species individually. This alternative 
    procedure allows an examination of the range of the adjusted chronic 
    values for each species.
    
        L. Obtain the FCV at Z by using the procedure described in 
    sections IV.J through O of this appendix.
        M. If the SMCV at Z of a commercially or recreationally 
    important species of the Great Lakes System is lower than the 
    calculated FCV at Z, then that SMCV shall be used as the FCV at Z 
    instead of the calculated FCV.
        N. The Final Chronic Equation is written as:
    
    FCV=e(L[ln(water quality characteristic)]+lnS-L[lnZ])
    
    Where:
    
    L=pooled chronic slope and S = FCV at Z.
    
        Because L, S, and Z are known, the FCV can be calculated for any 
    selected value of the water quality characteristic.
    
    VIII. Final Plant Value
    
        A. A Final Plant Value (FPV) is the lowest plant value that was 
    obtained with an important aquatic plant species in an acceptable 
    toxicity test for which the concentrations of the test material were 
    measured and the adverse effect was biologically important. 
    Appropriate measures of the toxicity of the material to aquatic 
    plants are used to compare the relative sensitivities of aquatic 
    plants and animals. Although procedures for conducting and 
    interpreting the results of toxicity tests with plants are not well-
    developed, results of tests with plants usually indicate that 
    criteria which adequately protect aquatic animals and their uses 
    will, in most cases, also protect aquatic plants and their uses.
        B. A plant value is the result of a 96-hour test conducted with 
    an alga or a chronic test conducted with an aquatic vascular plant.
    
        Note: A test of the toxicity of a metal to a plant shall not be 
    used if the medium contained an excessive amount of a complexing 
    agent, such as EDTA, that might affect the toxicity of the metal. 
    Concentrations of EDTA above 200 g/L should be considered 
    excessive.
    
        C. The FPV shall be obtained by selecting the lowest result from 
    a test with an important aquatic plant species in which the 
    concentrations of test material are measured and the endpoint is 
    biologically important.
    
    IX. Other Data
    
        Pertinent information that could not be used in earlier sections 
    might be available concerning adverse effects on aquatic organisms. 
    The most important of these are data on cumulative and delayed 
    toxicity, reduction in survival, growth, or reproduction, or any 
    other adverse effect that has been shown to be biologically 
    important. Delayed toxicity is an adverse effect to an organism that 
    results from, and occurs after the end of, its exposure to one or 
    more test materials. Especially important are data for species for 
    which no other data are available. Data from behavioral, 
    biochemical, physiological, microcosm, and field studies might also 
    be available. Data might be available from tests conducted in 
    unusual dilution water (see sections IV.D and VI.D of this 
    appendix), from chronic tests in which the concentrations were not 
    measured (see section VI.B of this appendix), from tests with 
    previously exposed organisms (see section II.F.3 of this appendix), 
    and from tests on formulated mixtures or emulsifiable concentrates 
    (see section II.D of this appendix). Such data might affect a 
    criterion if the data were obtained with an important species, the 
    test concentrations were measured, and the endpoint was biologically 
    important.
    
    X. Criterion
    
        A. A criterion consists of two concentrations: the CMC and the 
    Criterion Continuous Concentration (CCC).
        B. The CMC is equal to one-half the FAV. The CMC is an estimate 
    of the highest concentration of a material in the water column to 
    which an aquatic community can be exposed briefly without resulting 
    in an unacceptable effect.
        C. The CCC is equal to the lowest of the FCV or the FPV (if 
    available) unless other data (see section IX of this appendix) show 
    that a lower value should be used. The CCC is an estimate of the 
    highest concentration of a material in the water column to which an 
    aquatic community can be exposed indefinitely without resulting in 
    an unacceptable effect. If toxicity is related to a water quality 
    characteristic, the CCC is obtained from the Final Chronic Equation 
    or FPV (if available) that results in the lowest concentrations in 
    the usual range of the water quality characteristic, unless other 
    data (see section IX) show that a lower value should be used.
        D. Round both the CMC and the CCC to two significant digits.
        E. The criterion is stated as:
        The procedures described in the Tier I methodology indicate 
    that, except possibly where a commercially or recreationally 
    important species is very sensitive, aquatic organisms should not be 
    affected unacceptably if the four-day average concentration of (1) 
    does not exceed (2) g/L more than once every three years on 
    the average and if the one-hour average concentration does not 
    exceed (3) g/L more than once every three years on the 
    average.
    Where:
    
    (1) = insert name of material
    (2) = insert the CCC
    (3) = insert the CMC
    
        If the CMC averaging period of one hour or the CCC averaging 
    period of four days is inappropriate for the pollutant, or if the 
    once-in-three-year allowable excursion frequency is inappropriate 
    for the pollutant or for the sites to which a criterion is applied, 
    then the State may specify alternative averaging periods or 
    frequencies. The choice of an alternative averaging period or 
    frequency shall be justified by a scientifically defensible analysis 
    demonstrating that the alternative values will protect the aquatic 
    life uses of the water. Appropriate laboratory data and/or well-
    designed field biological surveys shall be submitted to EPA as 
    justification for differing averaging periods and/or frequencies of 
    exceedance.
    
    XI. Final Review
    
        A. The derivation of the criterion should be carefully reviewed 
    by rechecking each step of the Guidance in this part. Items that 
    should be especially checked are:
        1. If unpublished data are used, are they well documented?
        2. Are all required data available?
        3. Is the range of acute values for any species greater than a 
    factor of 10?
        4. Is the range of SMAVs for any genus greater than a factor of 
    10?
        5. Is there more than a factor of 10 difference between the four 
    lowest GMAVs?
        6. Are any of the lowest GMAVs questionable?
        7. Is the FAV reasonable in comparison with the SMAVs and GMAVs?
        8. For any commercially or recreationally important species of 
    the Great Lakes System, is the geometric mean of the acute values 
    from flow-through tests in which the concentrations of test material 
    were measured lower than the FAV?
        9. Are any of the chronic values used questionable?
        10. Are any chronic values available for acutely sensitive 
    species?
        11. Is the range of acute-chronic ratios greater than a factor 
    of 10?
        12. Is the FCV reasonable in comparison with the available acute 
    and chronic data?
        13. Is the measured or predicted chronic value for any 
    commercially or recreationally important species of the Great Lakes 
    System below the FCV?
        14. Are any of the other data important?
        15. Do any data look like they might be outliers?
        16. Are there any deviations from the Guidance in this part? Are 
    they acceptable?
        B. On the basis of all available pertinent laboratory and field 
    information, determine if the criterion is consistent with sound 
    scientific evidence. If it is not, another criterion, either higher 
    or lower, shall be derived consistent with the Guidance in this 
    part.
    
    Methodology for Deriving Aquatic Life Values: Tier II [[Page 15400]] 
    
    XII. Secondary Acute Value
    
        If all eight minimum data requirements for calculating an FAV 
    using Tier I are not met, a Secondary Acute Value (SAV) for the 
    waters of the Great Lakes System shall be calculated for a chemical 
    as follows:
        To calculate a SAV, the lowest GMAV in the database is divided 
    by the Secondary Acute Factor (SAF) (Table A-1 of this appendix) 
    corresponding to the number of satisfied minimum data requirements 
    listed in the Tier I methodology (section III.B.1 of this appendix). 
    (Requirements for definitions, data collection and data review, 
    contained in sections I, II, and IV shall be applied to calculation 
    of a SAV.) If all eight minimum data requirements are satisfied, a 
    Tier I criterion calculation may be possible. In order to calculate 
    a SAV, the database must contain, at a minimum, a genus mean acute 
    value (GMAV) for one of the following three genera in the family 
    Daphnidae--Ceriodaphnia sp., Daphnia sp., or Simocephalus sp.
        If appropriate, the SAV shall be made a function of a water 
    quality characteristic in a manner similar to that described in Tier 
    I.
    
    XIII. Secondary Acute-Chronic Ratio
    
        If three or more experimentally determined ACRs, meeting the 
    data collection and review requirements of Section VI of this 
    appendix, are available for the chemical, determine the FACR using 
    the procedure described in Section VI. If fewer than three 
    acceptable experimentally determined ACRs are available, use enough 
    assumed ACRs of 18 so that the total number of ACRs equals three. 
    Calculate the Secondary Acute-Chronic Ratio (SACR) as the geometric 
    mean of the three ACRs. Thus, if no experimentally determined ACRs 
    are available, the SACR is 18.
    
    XIV. Secondary Chronic Value
    
        Calculate the Secondary Chronic Value (SCV) using one of the 
    following:
    [GRAPHIC][TIFF OMITTED]TR23MR95.099
    
    
        If appropriate, the SCV will be made a function of a water 
    quality characteristic in a manner similar to that described in Tier 
    I.
    
    XV. Commercially or Recreationally Important Species
    
        If for a commercially or recreationally important species of the 
    Great Lakes System the geometric mean of the acute values or chronic 
    values from flow-through tests in which the concentrations of the 
    test materials were measured is lower than the calculated SAV or 
    SCV, then that geometric mean must be used as the SAV or SCV instead 
    of the calculated SAV or SCV.
    
    XVI. Tier II Value
    
        A. A Tier II value shall consist of two concentrations: the 
    Secondary Maximum Concentration (SMC) and the Secondary Continuous 
    Concentration (SCC).
        B. The SMC is equal to one-half of the SAV.
        C. The SCC is equal to the lowest of the SCV or the Final Plant 
    Value, if available, unless other data (see section IX of this 
    appendix) show that a lower value should be used.
        If toxicity is related to a water quality characteristic, the 
    SCC is obtained from the Secondary Chronic Equation or FPV, if 
    available, that results in the lowest concentrations in the usual 
    range of the water quality characteristic, unless other data (See 
    section IX of this appendix) show that a lower value should be used.
        D. Round both the SMC and the SCC to two significant digits.
        E. The Tier II value is stated as:
        The procedures described in the Tier II methodology indicate 
    that, except possibly where a locally important species is very 
    sensitive, aquatic organisms should not be affected unacceptably if 
    the four-day average concentration of (1) does not exceed (2) 
    g/L more than once every three years on the average and if 
    the one-hour average concentration does not exceed (3) g/L 
    more than once every three years on the average.
    
    Where:
    
    (1) = insert name of material
    (2) = insert the SCC
    (3) = insert the SMC
        As discussed above, States and Tribes have the discretion to 
    specify alternative averaging periods or frequencies (see section 
    X.E. of this appendix).
    
    XVII. Appropriate Modifications
    
        On the basis of all available pertinent laboratory and field 
    information, determine if the Tier II value is consistent with sound 
    scientific evidence. If it is not, another value, either higher or 
    lower, shall be derived consistent with the Guidance in this part.
    
                       Table A-1.-- Secondary Acute Factors                 
    ------------------------------------------------------------------------
                                                                  Adjustment
            Number of minimum data requirements satisfied           factor  
    ------------------------------------------------------------------------
    1...........................................................        21.9
    2...........................................................        13.0
    3...........................................................         8.0
    4...........................................................         7.0
    5...........................................................         6.1
    6...........................................................         5.2
    7...........................................................         4.3
    ------------------------------------------------------------------------
    
    Appendix B to Part 132--Great Lakes Water Quality Initiative
    
    Methodology for Deriving Bioaccumulation Factors
    
        Great Lakes States and Tribes shall adopt provisions consistent 
    with (as protective as) this appendix.
    
    I. Introduction
    
        A. The purpose of this methodology is to describe procedures for 
    deriving bioaccumulation factors (BAFs) to be used in the 
    calculation of Great Lakes Water Quality Guidance (Guidance) human 
    health Tier I criteria and Tier II values and wildlife Tier I 
    criteria. A subset of the human health BAFs are also used to 
    identify the chemicals that are considered bioaccumulative chemicals 
    of concern (BCCs).
        B. Bioaccumulation reflects uptake of a substance by aquatic 
    organisms exposed to the substance through all routes (i.e., ambient 
    water and food), as would occur in nature. Bioconcentration reflects 
    uptake of a substance by aquatic organisms exposed to the substance 
    only through the ambient water. Both BAFs and bioconcentration 
    factors (BCFs) are proportionality constants that describe the 
    relationship between the concentration of a substance in aquatic 
    organisms and its concentration in the ambient water. For the 
    Guidance in this part, BAFs, rather than BCFs, are used to calculate 
    Tier I criteria for human health and wildlife and Tier II values for 
    human health because they better account for the total exposure of 
    aquatic organisms to chemicals.
        C. For organic chemicals, baseline BAFs can be derived using 
    four methods. Measured baseline BAFs are derived from field-measured 
    BAFs; predicted baseline BAFs are derived using biota-sediment 
    accumulation factors (BSAFs) or are derived by multiplying a 
    laboratory-measured or predicted BCF by a food-chain multiplier 
    (FCM). The lipid content of the aquatic organisms is used to account 
    for partitioning of organic chemicals within organisms so that data 
    from different [[Page 15401]] tissues and species can be integrated. 
    In addition, the baseline BAF is based on the concentration of 
    freely dissolved organic chemicals in the ambient water to 
    facilitate extrapolation from one water to another.
        D. For inorganic chemicals, baseline BAFs can be derived using 
    two of the four methods. Baseline BAFs are derived using either 
    field-measured BAFs or by multiplying laboratory-measured BCFs by a 
    FCM. For inorganic chemicals, BAFs are assumed to equal BCFs (i.e., 
    the FCM is 1.0), unless chemical-specific biomagnification data 
    support using a FCM other than 1.0.
        E. Because both humans and wildlife consume fish from both 
    trophic levels 3 and 4, two baseline BAFs are needed to calculate 
    either a human health criterion or value or a wildlife criterion for 
    a chemical. When appropriate, ingestion through consumption of 
    invertebrates, plants, mammals, and birds in the diet of wildlife 
    species to be protected may be taken into account.
    
    II. Definitions
    
        Baseline BAF. For organic chemicals, a BAF that is based on the 
    concentration of freely dissolved chemical in the ambient water and 
    takes into account the partitioning of the chemical within the 
    organism; for inorganic chemicals, a BAF that is based on the wet 
    weight of the tissue.
        Baseline BCF. For organic chemicals, a BCF that is based on the 
    concentration of freely dissolved chemical in the ambient water and 
    takes into account the partitioning of the chemical within the 
    organism; for inorganic chemicals, a BCF that is based on the wet 
    weight of the tissue.
        Bioaccumulation. The net accumulation of a substance by an 
    organism as a result of uptake from all environmental sources.
        Bioaccumulation factor (BAF). The ratio (in L/kg) of a 
    substance's concentration in tissue of an aquatic organism to its 
    concentration in the ambient water, in situations where both the 
    organism and its food are exposed to and the ratio does not change 
    substantially over time.
        Bioconcentration. The net accumulation of a substance by an 
    aquatic organism as a result of uptake directly from the ambient 
    water through gill membranes or other external body surfaces.
        Bioconcentration factor (BCF). The ratio (in L/kg) of a 
    substance's concentration in tissue of an aquatic organism to its 
    concentration in the ambient water, in situations where the organism 
    is exposed through the water only and the ratio does not change 
    substantially over time.
        Biota-sediment accumulation factor (BSAF). The ratio (in kg of 
    organic carbon/kg of lipid) of a substance's lipid-normalized 
    concentration in tissue of an aquatic organism to its organic 
    carbon-normalized concentration in surface sediment, in situations 
    where the ratio does not change substantially over time, both the 
    organism and its food are exposed, and the surface sediment is 
    representative of average surface sediment in the vicinity of the 
    organism.
        Depuration. The loss of a substance from an organism as a result 
    of any active or passive process.
        Food-chain multiplier (FCM). The ratio of a BAF to an 
    appropriate BCF.
        Octanol-water partition coefficient (KOW). The ration of 
    the concentration of a substance in the n-octanol phase to its 
    concentration in the aqueous phase in an equilibrated two-phase 
    octanol-water system. For log KOW, the log of the octanol-water 
    partition coefficient is a base 10 logarithm.
        Uptake. Acquisition of a substance from the environment by an 
    organism as a result of any active or passive process.
    
    III. Review and Selection of Data
    
        A. Data Sources.  Measured BAFs, BSAFs and BCFs are assembled 
    from available sources including the following:
        1. EPA Ambient Water Quality Criteria documents issued after 
    January 1, 1980.
        2. Published scientific literature.
        3. Reports issued by EPA or other reliable sources.
        4. Unpublished data.
        One useful source of references is the Aquatic Toxicity 
    Information Retrieval (AQUIRE) database.
        B. Field-Measured BAFs. The following procedural and quality 
    assurance requirements shall be met for field-measured BAFs:
        1. The field studies used shall be limited to those conducted in 
    the Great Lakes System with fish at or near the top of the aquatic 
    food chain (i.e., in trophic levels 3 and/or 4).
        2. The trophic level of the fish species shall be determined.
        3. The site of the field study should not be so unique that the 
    BAF cannot be extrapolated to other locations where the criteria and 
    values will apply.
        4. For organic chemicals, the percent lipid shall be either 
    measured or reliably estimated for the tissue used in the 
    determination of the BAF.
        5. The concentration of the chemical in the water shall be 
    measured in a way that can be related to particulate organic carbon 
    (POC) and/or dissolved organic carbon (DOC) and should be relatively 
    constant during the steady-state time period.
        6. For organic chemicals with log Kow greater than four, 
    the concentrations of POC and DOC in the ambient water shall be 
    either measured or reliably estimated.
        7. For inorganic and organic chemicals, BAFs shall be used only 
    if they are expressed on a wet weight basis; BAFs reported on a dry 
    weight basis cannot be converted to wet weight unless a conversion 
    factor is measured or reliably estimated for the tissue used in the 
    determination of the BAF.
        C. Field-Measured BSAFs. The following procedural and quality 
    assurance requirements shall be met for field-measured BSAFs:
        1. The field studies used shall be limited to those conducted in 
    the Great Lakes System with fish at or near the top of the aquatic 
    food chain (i.e., in trophic levels 3 and/or 4).
        2. Samples of surface sediments (0-1 cm is ideal) shall be from 
    locations in which there is net deposition of fine sediment and is 
    representative of average surface sediment in the vicinity of the 
    organism.
        3. The Kows used shall be acceptable quality as described 
    in section III.F below.
        4. The site of the field study should not be so unique that the 
    resulting BAF cannot be extrapolated to other locations where the 
    criteria and values will apply.
        5. The tropic level of the fish species shall be determined.
        6. The percent lipid shall be either measured or reliably 
    estimated for the tissue used in the determination of the BAF.
        D. Laboratory-Measured BCFs. The following procedural and 
    quality assurance requirements shall be met for laboratory-measured 
    BCFs:
        1. The test organism shall not be diseased, unhealthy, or 
    adversely affected by the concentration of the chemical.
        2. The total concentration of the chemical in the water shall be 
    measured and should be relatively constant during the steady-state 
    time period.
        3. The organisms shall be exposed to the chemical using a flow-
    through or renewal procedure.
        4. For organic chemicals, the percent lipid shall be either 
    measured or reliably estimated for the tissue used in the 
    determination of the BCF.
        5. For organic chemicals with log Kow greater than four, 
    the concentrations of POC and DOC in the test solution shall be 
    either measured or reliably estimated.
        6. Laboratory-measured BCFs should be determined using fish 
    species, but BCFs determined with molluscs and other invertebrates 
    may be used with caution. For example, because invertebrates 
    metabolize some chemicals less efficiently than vertebrates, a 
    baseline BCF determined for such a chemical using invertebrates is 
    expected to be higher than a comparable baseline BCF determined 
    using fish.
        7. If laboratory-measured BCFs increase or decrease as the 
    concentration of the chemical increases in the test solutions in a 
    bioconcentration test, the BCF measured at the lowest test 
    concentration that is above concentrations existing in the control 
    water shall be used (i.e., a BCF should be calculated from a control 
    treatment). The concentrations of an inorganic chemical in a 
    bioconcentration test should be greater than normal background 
    levels and greater than levels required for normal nutrition of the 
    test species if the chemical is a micronutrient, but below levels 
    that adversely affect the species. Bioaccummulation of an inorganic 
    chemical might be overestimated if concentrations are at or below 
    normal background levels due to, for example, nutritional 
    requirements of the test organisms.
        8. For inorganic and organic chemicals, BCFs shall be used only 
    if they are expressed on a wet weight basis. BCFs reported on a dry 
    weight basis cannot be converted to wet weight unless a conversion 
    factor is measured or reliably estimated for the tissue used in the 
    determination of the BAF.
        9. BCFs for organic chemicals may be based on measurement or 
    radioactivity only when the BCF is intended to include metabolites 
    or when there is confidence that there is no interference due to 
    metabolites.
        10. The calculation of the BCF must appropriately address growth 
    dilution.
        11. Other aspects of the methodology used should be similar to 
    those described by ASTM (1990). [[Page 15402]] 
        E. Predicted BCFs. The following procedural and quality 
    assurance requirements shall be met for predicted BCFs:
        1. The Kow used shall be of acceptable quality as described 
    in section III.F below.
        2. The predicted baseline BCF shall be calculated using the 
    equation: predicted baseline BCF = Kow
        where:
        Kow = octanol-water partition coefficient.
        F. Octanol-Water Partition Coefficient (Kow). 1. The value 
    of Kow used for an organic chemical shall be determined by 
    giving priority to the experimental and computational techniques 
    used as follows:
        Log Kow < 4:="" ------------------------------------------------------------------------="" priority="" technique="" ------------------------------------------------------------------------="" 1..................................="" slow-stir.="" 1..................................="" generator-column.="" 1..................................="" shake-flask.="" 2..................................="" reverse-phase="" liquid="" chromatography="" on="" c18="" chromatography="" packing="" with="" extrapolation="" to="" zero="" percent="" solvent.="" 3..................................="" reverse-phase="" liquid="" chromatography="" on="" c18="" chromatography="" packing="" without="" extrapolation="" to="" zero="" percent="" solvent.="" 4..................................="" calculated="" by="" the="" clogp="" program.="" ------------------------------------------------------------------------="" log="">ow > 4:
    
    ------------------------------------------------------------------------
       Priority                            Technique                        
    ------------------------------------------------------------------------
    1............  Slow Stir.                                               
    1............  Generator-column.                                        
    2............  Reverse-phase liquid chromatography on C18 chromatography
                    packing with extrapolation to zero percent solvent.     
    3............  Reverse-phase liquid chromatography on C18 chromatography
                    packing without extrapolation to zero percent solvent.  
    4............  Shake-flask.                                             
    5............  Calculated by the CLOGP program.                         
    ------------------------------------------------------------------------
    
        2. The CLOGP program is a computer program available from Pomona 
    College. A value of Kow that seems to be different from the 
    others should be considered an outlier and not used. The value of 
    Kow used for an organic chemical shall be the geometric mean of 
    the available Kows with highest priority or can be calculated 
    from the arithmetic mean of the available log Kow with the 
    highest priority. Because it is an intermediate value in the 
    derivation of a BAF, the value used for the Kow of a chemical 
    should not be rounded to fewer than three significant digits and a 
    value for log Kow should not be rounded to fewer than three 
    significant digits after the decimal point.
        G. This methodology provides overall guidance for the derivation 
    of BAFs, but it cannot cover all the decisions that must be made in 
    the review and selection of acceptable data. Professional judgment 
    is required throughout the process. A degree of uncertainty is 
    associated with the determination of any BAF, BSAF, BCF or Kow. 
    The amount of uncertainty in a baseline BAF depends on both the 
    quality of data available and the method used to derive the BAF.
        H. Hereinafter in this methodology, the terms BAF, BSAF, BCF and 
    Kow refer to ones that are consistent with the procedural and 
    quality assurance requirements given above.
    
    IV. Four Methods for Deriving Baseline BAFs
    
        Baseline BAFs shall be derived using the following four methods, 
    which are listed from most preferred to least preferred:
        A. A measured baseline BAF for an organic or inorganic chemical 
    derived from a field study of acceptable quality.
        B. A predicted baseline BAF for an organic chemical derived 
    using field-measured BSAFs of acceptable quality.
        C. A predicted baseline BAF for an organic or inorganic chemical 
    derived from a BCF measured in a laboratory study of acceptable 
    quality and a FCM.
        D. A predicted baseline BAF for an organic chemical derived from 
    a Kow of acceptable quality and a FCM.
        For comparative purposes, baseline BAFs should be derived for 
    each chemical by as many of the four methods as available data 
    allow.
    
    V. Calculation of Baseline BAFs for Organic Chemicals
    
        A. Lipid Normalization. 1. It is assumed that BAFs and BCFs for 
    organic chemicals can be extrapolated on the basis of percent lipid 
    from one tissue to another and from one aquatic species to another 
    in most cases.
        2. Because BAFs and BCFs for organic chemicals are related to 
    the percent lipid, it does not make any difference whether the 
    tissue sample is whole body or edible portion, but both the BAF (or 
    BCF) and the percent lipid must be determined for the same tissue. 
    The percent lipid of the tissue should be measured during the BAF or 
    BCF study, but in some cases it can be reliably estimated from 
    measurements on tissue from other organisms. If percent lipid is not 
    reported for the test organisms in the original study, it may be 
    obtained from the author; or, in the case of a laboratory study, 
    lipid data for the same or a comparable laboratory population of 
    test organisms that were used in the original study may be used.
        3. The lipid-normalized concentration, Cl, of a chemical in 
    tissue is defined using the following equation:
    [GRAPHIC][TIFF OMITTED]TR23MR95.100
    
    
    Where:
    
    CB=concentration of the organic chemical in the tissue of 
    aquatic biota (either whole organism or specified tissue) 
    (g/g).
    fl=fraction of the tissue that is lipid.
    
        B. Bioavailability. By definition, baseline BAFs and BCFs for 
    organic chemicals, whether measured or predicted are based on the 
    concentration of the chemical that is freely dissolved in the 
    ambient water in order to account for bioavailability. For the 
    purposes of this Guidance in this part, the relationship between the 
    total concentration of the chemical in the water (i.e., that which 
    is freely dissolved plus that which is sorbed to particulate organic 
    carbon or to dissolved organic carbon) to the freely dissolved 
    concentration of the chemical in the ambient water shall be 
    calculated using the following equation:
    [GRAPHIC][TIFF OMITTED]TR23MR95.101
    
    
    Where:
    
    Cfdw=freely dissolved concentration of the organic 
    chemical in the ambient water;
    Ctw=total concentration of the organic chemical in the 
    ambient water;
    ffd=fraction of the total chemical in the ambient water that is 
    freely dissolved.
    
        The fraction of the total chemical in the ambient water that is 
    freely dissolved, ffd, shall be calculated using the following 
    equation:
    [GRAPHIC][TIFF OMITTED]TR23MR95.102
    
    
    Where:
    
    DOC=concentration of dissolved organic carbon, kg of dissolved 
    organic carbon/L of water.
    KOW=octanol-water partition coefficient of the chemical.
    POC=concentration of particulate organic carbon, kg of particulate 
    organic carbon/L of water.
    
        C. Food-Chain Multiplier. In the absence of a field-measured BAF 
    or a predicted BAF derived from a BSAF, a FCM shall be used to 
    calculate the baseline BAF for trophic levels 3 and 4 from a 
    laboratory-measured or predicted BCF. For an organic chemical, the 
    FCM used shall be derived from Table B-1 using the chemical's log 
    KOW and linear interpolation. A FCM greater than 1.0 applies to 
    most organic chemicals with a log KOW of four or more. The 
    trophic level used shall take into account the age or size of the 
    fish species consumed by the human, avian or mammalian predator 
    because, for some species of fish, the young are in trophic level 3 
    whereas the adults are in trophic level 4.
        D. Calculation of a Baseline BAF from a Field-Measured BAF. A 
    baseline BAF shall be calculated from a field-measured BAF of 
                        acceptable quality using the following equation:
    [[Page 15403]]
    
    [GRAPHIC][TIFF OMITTED]TR23MR95.103
    
    
    Where:
    
    BAFtT=BAF based on total concentration in tissue and 
    water.
    fl=fraction of the tissue that is lipid.
    ffd=fraction of the total chemical that is freely dissolved in 
    the ambient water.
    
    The trophic level to which the baseline BAF applies is the same as 
    the trophic level of the organisms used in the determination of the 
    field-measured BAF. For each trophic level, a species mean measured 
    baseline BAF shall be calculated as the geometric mean if more than 
    one measured baseline BAF is available for a given species. For each 
    trophic level, the geometric mean of the species mean measured 
    baseline BAFs shall be calculated. If a baseline BAF based on a 
    measured BAF is available for either trophic level 3 or 4, but not 
    both, a measured baseline BAF for the other trophic level shall be 
    calculated using the ratio of the FCMs that are obtained by linear 
    interpolation from Table B-1 for the chemical.
        E. Calculation of a Baseline BAF from a Field-Measured BSAF. 1. 
    A baseline BAF for organic chemical ``i'' shall be calculated from a 
    field-measured BSAF of acceptable quality using the following 
    equation:
    [GRAPHIC][TIFF OMITTED]TR23MR95.105
    
    
    Where:
    
    (BSAF)i=BSAF for chemical ``i''.
    (BSAF)r=BSAF for the reference chemical ``r''.
    (KOW)i=octanol-water partition coefficient for chemical 
    ``i''.
    (KOW)r=octanol-water partition coefficient for the 
    reference chemical ``r''.
    
        2. A BSAF shall be calculated using the following equation:
    [GRAPHIC][TIFF OMITTED]TR23MR95.106
    
    
    Where:
    
    Ct=the lipid-normalized concentration of the chemical in 
    tissue.
    CSOC=the organic carbon-normalized concentration of the 
    chemical in sediment.
    
        3. The organic carbon-normalized concentration of a chemical in 
    sediment, CSOC, shall be calculated using the following 
    equation:
    [GRAPHIC][TIFF OMITTED]TR23MR95.107
    
    
    
    Where:
    
    CS=concentration of chemical in sediment (g/g 
    sediment).
    fOC=fraction of the sediment that is organic carbon.
    
        4. Predicting BAFs from BSAFs requires data from a steady-state 
    (or near steady-state) condition between sediment and ambient water 
    for both a reference chemical ``r'' with a field-measured 
    BAFlfd and other chemicals ``n=i'' for which BSAFs are to 
    be determined.
        5. The trophic level to which the baseline BAF applies is the 
    same as the trophic level of the organisms used in the determination 
    of the BSAF. For each trophic level, a species mean baseline BAF 
    shall be calculated as the geometric mean if more than one baseline 
    BAF is predicted from BSAFs for a given species. For each trophic 
    level, the geometric mean of the species mean baseline BAFs derived 
    using BSAFs shall be calculated.
        6. If a baseline BAF based on a measured BSAF is available for 
    either trophic level 3 or 4, but not both, a baseline BAF for the 
    other trophic level shall be calculated using the ratio of the FCMs 
    that are obtained by linear interpolation from Table B-1 for the 
    chemical.
        F. Calculation of a Baseline BAF from a Laboratory-Measured BCF. 
    A baseline BAF for trophic level 3 and a baseline BAF for trophic 
    level 4 shall be calculated from a laboratory-measured BCF of 
    acceptable quality and a FCM using the following equation:
    [GRAPHIC][TIFF OMITTED]TR23MR95.108
    
    
    Where:
    
    BCFtT=BCF based on total concentration in tissue and 
    water.
    fl=fraction of the tissue that is lipid.
    ffd=fraction of the total chemical in the test water that is 
    freely dissolved.
    FCM=the food-chain multiplier obtained from Table B-1 by linear 
    interpolation for trophic level 3 or 4, as necessary.
    
    For each trophic level, a species mean baseline BAF shall be 
    calculated as the geometric mean if more than one baseline BAF is 
    predicted from laboratory-measured BCFs for a given species. For 
    each trophic level, the geometric mean of the species mean baseline 
    BAFs based on laboratory-measured BCFs shall be calculated.
        G. Calculation of a Baseline BAF from an Octanol-Water Partition 
    Coefficient. A baseline BAF for trophic level 3 and a baseline BAF 
    for trophic level 4 shall be calculated from a KOW of 
    acceptable quality and a FCM using the following equation:
        Baseline BAF=(FCM) (predicted baseline BCF)=(FCM) (KOW)
    
    Where:
    
    FCM=the food-chain multiplier obtained from Table B-1 by linear 
    interpolation for trophic level 3 or 4, as necessary.
    KOW=octanol-water partition coefficient.
    
    VI. Human Health and Wildlife BAFs for Organic Chemicals
    
        A. To calculate human health and wildlife BAFs for an organic 
    chemical, the KOW of the [[Page 15404]] chemical shall be used 
    with a POC concentration of 0.00000004 kg/L and a DOC concentration 
    of 0.000002 kg/L to yield the fraction freely dissolved:
    [GRAPHIC][TIFF OMITTED]TR23MR95.109
    
    
        B. The human health BAFs for an organic chemical shall be 
    calculated using the following equations:
        For trophic level 3:
    [GRAPHIC][TIFF OMITTED]TR23MR95.110
    
    
        For trophic level 4:
    [GRAPHIC][TIFF OMITTED]TR23MR95.111
    
    
    Where:
    
        0.0182 and 0.0310 are the standardized fraction lipid values for 
    trophic levels 3 and 4, respectively, that are used to derive human 
    health criteria and values for the GLI.
        C. The wildlife BAFs for an organic chemical shall be calculated 
    using the following equations:
        For trophic level 3:
    [GRAPHIC][TIFF OMITTED]TR23MR95.112
    
    
        For trophic level 4:
    [GRAPHIC][TIFF OMITTED]TR23MR95.113
    
    
    Where:
        0.0646 and 0.1031 are the standardized fraction lipid values for 
    trophic levels 3 and 4, respectively, that are used to derive 
    wildlife criteria for the GLI.
    
    VII. Human Health and Wildlife BAFs for Inorganic Chemicals
    
        A. For inorganic chemicals, the baseline BAFs for trophic levels 
    3 and 4 are both assumed to equal the BCF determined for the 
    chemical with fish, i.e., the FCM is assumed to be 1 for both 
    trophic levels 3 and 4. However, a FCM greater than 1 might be 
    applicable to some metals, such as mercury, if, for example, an 
    organometallic form of the metal biomagnifies.
        B. BAFs for Human Health Criteria and Values.
        1. Measured BAFs and BCFs used to determine human health BAFs 
    for inorganic chemicals shall be based on edible tissue (e.g., 
    muscle) of freshwater fish unless it is demonstrated that whole-body 
    BAFs or BCFs are similar to edible-tissue BAFs or BCFs. BCFs and 
    BAFs based on measurements of aquatic plants and invertebrates 
    should not be used in the derivation of human health criteria and 
    values.
        2. If one or more field-measured baseline BAFs for an inorganic 
    chemical are available from studies conducted in the Great Lakes 
    System with the muscle of fish:
        a. For each trophic level, a species mean measured baseline BAF 
    shall be calculated as the geometric mean if more than one measured 
    BAF is available for a given species; and
        b. For each trophic level, the geometric mean of the species 
    mean measured baseline BAFs shall be used as the human health BAF 
    for that chemical.
        3. If an acceptable measured baseline BAF is not available for 
    an inorganic chemical and one or more acceptable edible-portion 
    laboratory-measured BCFs are available for the chemical, a predicted 
    baseline BAF shall be calculated by multiplying the geometric mean 
    of the BCFs times a FCM. The FCM will be 1.0 unless chemical-
    specific biomagnification data support using a multiplier other than 
    1.0. The predicted baseline BAF shall be used as the human health 
    BAF for that chemical.
        C. BAFs for Wildlife Criteria.
        1. Measured BAFs and BCFs used to determine wildlife BAFs for 
    inorganic chemicals shall be based on whole-body freshwater fish and 
    invertebrate data unless it is demonstrated that edible-tissue BAFs 
    or BCFs are similar to whole-body BAFs or BCFs.
    [[Page 15405]]
    
        2. If one or more field-measured baseline BAFs for an inorganic 
    chemical are available from studies conducted in the Great Lakes 
    System with whole body of fish or invertebrates:
        2. For each trophic level, a species mean measured baseline BAF 
    shall be calculated as the geometric mean if more than one measured 
    BAF is available for a given species.
        b. For each trophic level, the geometric mean of the species 
    mean measured baseline BAFs shall be used as the wildlife BAF for 
    that chemical.
        3. If an acceptable measured baseline BAF is not available for 
    an inorganic chemical and one or more acceptable whole-body 
    laboratory-measured BCFs are available for the chemical, a predicted 
    baseline BAF shall be calculated by multiplying the geometric mean 
    of the BCFs times a FCM. The FCM will be 1.0 unless chemical-
    specific biomagnification data support using a multiplier other than 
    1.0. The predicted baseline BAF shall be used as the wildlife BAF 
    for that chemical.
    
    VIII. Final Review
    
        For both organic and inorganic chemicals, human health and 
    wildlife BAFs for both trophic levels shall be reviewed for 
    consistency with all available data concerning the bioaccumulation, 
    bioconcentration, and metabolism of the chemical. For example, 
    information concerning octanol-water partitioning, molecular size, 
    or other physicochemical properties that might enhance or inhibit 
    bioaccumulation should be considered for organic chemicals. BAFs 
    derived in accordance with this methodology should be modified if 
    changes are justified by available data.
    
    IX. Literature Cited
    
        ASTM. 1990. Standard Practice for Conducting Bioconcentration 
    Tests with Fishes and Saltwater Bivalve Molluscs. Standard E 1022. 
    American Society for Testing and Materials, Philadelphia, PA.
    
         Table B-1.--Food-Chain Multipliers for Trophic Levels 2, 3 & 4     
    ------------------------------------------------------------------------
                                         Trophic     Trophic\1\    Trophic  
                 Log Kow                 level 2      level 3      level 4  
    ------------------------------------------------------------------------
    2.0..............................        1.000        1.005        1.000
    2.5..............................        1.000        1.010        1.002
    3.0..............................        1.000        1.028        1.007
    3.1..............................        1.000        1.034        1.007
    3.2..............................        1.000        1.042        1.009
    3.3..............................        1.000        1.053        1.012
    3.4..............................        1.000        1.067        1.014
    3.5..............................        1.000        1.083        1.019
    3.6..............................        1.000        1.103        1.023
    3.7..............................        1.000        1.128        1.033
    3.8..............................        1.000        1.161        1.042
    3.9..............................        1.000        1.202        1.054
    4.0..............................        1.000        1.253        1.072
    4.1..............................        1.000        1.315        1.096
    4.2..............................        1.000        1.380        1.130
    4.3..............................        1.000        1.491        1.178
    4.4..............................        1.000        1.614        1.242
    4.5..............................        1.000        1.766        1.334
    4.6..............................        1.000        1.950        1.459
    4.7..............................        1.000        2.175        1.633
    4.8..............................        1.000        2.452        1.871
    4.9..............................        1.000        2.780        2.193
    5.0..............................        1.000        3.181        2.612
    5.1..............................        1.000        3.643        3.162
    5.2..............................        1.000        4.188        3.873
    5.3..............................        1.000        4.803        4.742
    5.4..............................        1.000        5.502        5.821
    5.5..............................        1.000        6.266        7.079
    5.6..............................        1.000        7.096        8.551
    5.7..............................        1.000        7.962       10.209
    5.8..............................        1.000        8.841       12.050
    5.9..............................        1.000        9.716       13.964
    6.0..............................        1.000       10.556       15.996
    6.1..............................        1.000       11.337       17.783
    6.2..............................        1.000       12.064       19.907
    6.3..............................        1.000       12.691       21.677
    6.4..............................        1.000       13.228       23.281
    6.5..............................        1.000       13.662       24.604
    6.6..............................        1.000       13.980       25.645
    6.7..............................        1.000       14.223       26.363
    6.8..............................        1.000       14.355       26.669
    6.9..............................        1.000       14.388       26.669
    7.0..............................        1.000       14.305       26.242
    7.1..............................        1.000       14.142       25.468
    7.2..............................        1.000       13.852       24.322
    7.3..............................        1.000       13.474       22.856
    7.4..............................        1.000       12.987       21.038
    7.5..............................        1.000       12.517       18.967
    7.6..............................        1.000       11.708       16.749
    7.7..............................        1.000       10.914       14.388
    7.8..............................        1.000       10.069       12.050
    7.9..............................        1.000        9.162        9.840
    8.0..............................        1.000        8.222        7.798
    8.1..............................        1.000        7.278        6.012
    [[Page 15406]]                                                          
                                                                            
    8.2..............................        1.000        6.361        4.519
    8.3..............................        1.000        5.489        3.311
    8.4..............................        1.000        4.683        2.371
    8.5..............................        1.000        3.949        1.663
    8.6..............................        1.000        3.296        1.146
    8.7..............................        1.000        2.732        0.778
    8.8..............................        1.000        2.246        0.521
    8.9..............................        1.000        1.837        0.345
    9.0..............................        1.000        1.493        0.226
    ------------------------------------------------------------------------
    \1\The FCMs for trophic level 3 are the geometric mean of the FCMs for  
      sculpin and alewife.                                                  
    
    Appendix C to Part 132--Great Lakes Water Quality Initiative 
    Methodologies for Development of Human Health Criteria and Values
    
        Great Lakes States and Tribes shall adopt provisions consistent 
    with (as protective as) this appendix.
    
    I. Introduction
    
        Great Lakes States and Tribes shall adopt provisions consistent 
    with this appendix C to ensure protection of human health.
        A. Goal. The goal of the human health criteria for the Great 
    Lakes System is the protection of humans from unacceptable exposure 
    to toxicants via consumption of contaminated fish and drinking water 
    and from ingesting water as a result of participation in water-
    oriented recreational activities.
        B. Definitions.
        Acceptable daily exposure (ADE). An estimate of the maximum 
    daily dose of a substance which is not expected to result in adverse 
    noncancer effects to the general human population, including 
    sensitive subgroups.
        Adverse effect. Any deleterious effect to organisms due to 
    exposure to a substance. This includes effects which are or may 
    become debilitating, harmful or toxic to the normal functions of the 
    organism, but does not include non-harmful effects such as tissue 
    discoloration alone or the induction of enzymes involved in the 
    metabolism of the substance.
        Carcinogen. A substance which causes an increased incidence of 
    benign or malignant neoplasms, or substantially decreases the time 
    to develop neoplasms, in animals or humans. The classification of 
    carcinogens is discussed in section II.A of appendix C to part 132.
        Human cancer criterion (HCC). A Human Cancer Value (HCV) for a 
    pollutant that meets the minimum data requirements for Tier I 
    specified in appendix C.
        Human cancer value (HCV). The maximum ambient water 
    concentration of a substance at which a lifetime of exposure from 
    either: drinking the water, consuming fish from the water, and 
    water-related recreation activities; or consuming fish from the 
    water, and water-related recreation activities, will represent a 
    plausible upper-bound risk of contracting cancer of one in 100,000 
    using the exposure assumptions specified in the Methodologies for 
    the Development of Human Health Criteria and Values in appendix C of 
    this part.
        Human noncancer criterion (HNC). A Human Noncancer Value (HNV) 
    for a pollutant that meets the minimum data requirements for Tier I 
    specified in appendix C of this part.
        Human noncancer value (HNV). The maximum ambient water 
    concentration of a substance at which adverse noncancer effects are 
    not likely to occur in the human population from lifetime exposure 
    via either: drinking the water, consuming fish from the water, and 
    water-related recreation activities; or consuming fish from the 
    water, and water-related recreation activities using the 
    Methodologies for the Development of Human Health criteria and 
    Values in appendix C of this part.
        Linearized multi-stage model. A conservative mathematical model 
    for cancer risk assessment. This model fits linear dose-response 
    curves to low doses. It is consistent with a no-threshold model of 
    carcinogenesis, i.e., exposure to even a very small amount of the 
    substance is assumed to produce a finite increased risk of cancer.
        Lowest observed adverse effect level (LOAEL). The lowest tested 
    dose or concentration of a substance which resulted in an observed 
    adverse effect in exposed test organisms when all higher doses or 
    concentrations resulted in the same or more severe effects.
        No observed adverse effect level (NOAEL). The highest tested 
    dose or concentration of a substance which resulted in no observed 
    adverse effect in exposed test organisms where higher doses or 
    concentrations resulted in an adverse effect.
        Quantitative structure activity relationship (OSAR) or structure 
    activity relationship (SAR). A mathematical relationship between a 
    property (activity) of a chemical and a number of descriptors of the 
    chemical. These descriptors are chemical or physical characteristics 
    obtained experimentally or predicted from the structure of the 
    chemical.
        Relative source contribution (RSC). The factor (percentage) used 
    in calculating an HNV or HNC to account for all sources of exposure 
    to a contaminant. The RSC reflects the percent of total exposure 
    which can be attributed to surface water through water intake and 
    fish consumption.
        Risk associated dose (RAD). A dose of a known or presumed 
    carcinogenic substance in (mg/kg/day) which, over a lifetime of 
    exposure, is estimated to be associated with a plausible upper bound 
    incremental cancer risk equal to one in 100,000.
        Slope factor. Also known as q1*, slope factor is the 
    incremental rate of cancer development calculated through use of a 
    linearized multistage model or other appropriate model. It is 
    expressed in (mg/kg/day) of exposure to the chemical in question.
        Threshold effect. An effect of a substance for which there is a 
    theoretical or empirically established dose or concentration below 
    which the effect does not occur.
        Uncertainty factor (UF). One of several numeric factors used in 
    operationally deriving criteria from experimental data to account 
    for the quality or quantity of the available data.
        C. Level of Protection. The criteria developed shall provide a 
    level of protection likely to be without appreciable risk of 
    carcinogenic and/or noncarcinogenic effects. Criteria are a function 
    of the level of designated risk or no adverse effect estimation, 
    selection of data and exposure assumptions. Ambient criteria for 
    single carcinogens shall not be set at a level representing a 
    lifetime upper-bound incremental risk greater than one in 100,000 of 
    developing cancer using the hazard assessment techniques and 
    exposure assumptions described herein. Criteria affording protection 
    from noncarcinogenic effects shall be established at levels that, 
    taking into account uncertainties, are considered likely to be 
    without an appreciable risk of adverse human health effects (i.e., 
    acute, subchronic and chronic toxicity including reproductive and 
    developmental effects) during a lifetime of exposure, using the risk 
    assessment techniques and exposure assumptions described herein.
        D. Two-tiered Classification. Chemical concentration levels in 
    surface water protective of human health shall be derived based on 
    either a Tier I or Tier II classification. The two Tiers are 
    primarily distinguished by the amount of toxicity data available for 
    deriving the concentration levels and the quantity and quality of 
    data on bioaccumulation.
    
    II. Minimum Data Requirements
    
        The best available toxicity data on the adverse health effects 
    of a chemical and the best data on bioaccumulation factors shall be 
    used when developing human health Tier I criteria or Tier II values. 
    The best available toxicity data shall include data from well- 
    [[Page 15407]] conducted epidemiologic and/or animal studies which 
    provide, in the case of carcinogens, an adequate weight of evidence 
    of potential human carcinogenicity and, in the case of 
    noncarcinogens, a dose-response relationship involving critical 
    effects biologically relevant to humans. Such information should be 
    obtained from the EPA Integrated Risk Information System (IRIS) 
    database, the scientific literature, and other informational 
    databases, studies and/or reports containing adverse health effects 
    data of adequate quality for use in this procedure. Strong 
    consideration shall be given to the most currently available 
    guidance provided by IRIS in deriving criteria or values, 
    supplemented with any recent data not incorporated into IRIS. When 
    deviations from IRIS are anticipated or considered necessary, it is 
    strongly recommended that such actions be communicated to the EPA 
    Reference Dose (RfD) and/or the Cancer Risk Assessment Verification 
    Endeavor (CRAVE) workgroup immediately. The best available 
    bioaccumulation data shall include data from field studies and well-
    conducted laboratory studies.
        A. Carcinogens. Tier I criteria and Tier II values shall be 
    derived using the methodologies described in section III.A of this 
    appendix when there is adequate evidence of potential human 
    carcinogenic effects for a chemical. It is strongly recommended that 
    the EPA classification system for chemical carcinogens, which is 
    described in the 1986 EPA Guidelines for Carcinogenic Risk 
    Assessment (U.S. EPA, 1986), or future modifications thereto, be 
    used in determining whether adequate evidence of potential 
    carcinogenic effects exists. Carcinogens are classified, depending 
    on the weight of evidence, as either human carcinogens, probable 
    human carcinogens, or possible human carcinogens. The human evidence 
    is considered inadequate and therefore the chemical cannot be 
    classified as a human carcinogen, if one of two conditions exists: 
    (a) there are few pertinent data, or (b) the available studies, 
    while showing evidence of association, do not exclude chance, bias, 
    or confounding and therefore a casual interpretation is not 
    credible. The animal evidence is considered inadequate, and 
    therefore the chemical cannot be classified as a probable or 
    possible human carcinogen, when, because of major qualitative or 
    quantitative limitations, the evidence cannot be interpreted as 
    showing either the presence or absence of a carcinogenic effect.
        Chemicals are described as ``human carcinogens'' when there is 
    sufficient evidence from epidemiological studies to support a causal 
    association between exposure to the chemicals and cancer. Chemicals 
    described as ``probable human carcinogens'' include chemicals for 
    which the weight of evidence of human carcinogenicity based on 
    epidemiological studies is limited. Limited human evidence is that 
    which indicates that a causal interpretation is credible, but that 
    alternative explanations, such as chance, bias, or confounding, 
    cannot adequately be excluded. Probable human carcinogens are also 
    agents for which there is sufficient evidence from animal studies 
    and for which there is inadequate evidence or no data from 
    epidemiologic studies. Sufficient animal evidence is data which 
    indicates that there is an increased incidence of malignant tumors 
    or combined malignant and benign tumors: (a) in multiple species or 
    strains; (b) in multiple experiments (e.g., with different routes of 
    administration or using different dose levels); or (c) to an unusual 
    degree in a single experiment with regard to high incidence, unusual 
    site or type of tumor, or early age at onset. Additional evidence 
    may be provided by data on dose-response effects, as well as 
    information from short-term tests (such as mutagenicity/genotoxicity 
    tests which help determine whether the chemical interacts directly 
    with DNA) or on chemical structure, metabolism or mode of action.
        ``Possible human carcinogens'' are chemicals with limited 
    evidence of carcinogenicity in animals in the absence of human data. 
    Limited animal evidence is defined as data which suggests a 
    carcinogenic effect but are limited because: (a) The studies involve 
    a single species, strain, or experiment and do not meet criteria for 
    sufficient evidence (see preceding paragraph); or (b) the 
    experiments are restricted by inadequate dosage levels, inadequate 
    duration of exposure to the agent, inadequate period of follow-up, 
    poor survival, too few animals, or inadequate reporting; or (c) the 
    studies indicate an increase in the incidence of benign tumors only. 
    More specifically, this group can include a wide variety of 
    evidence, e.g., (a) a malignant tumor response in a single well-
    conducted experiment that does not meet conditions for sufficient 
    evidence, (b) tumor response of marginal statistical significance in 
    studies having inadequate design or reporting, (c) benign but not 
    malignant tumors with an agent showing no response in a variety of 
    short-term tests for mutagenicity, and (d) response of marginal 
    statistical significance in a tissue known to have a high or 
    variable background rate.
        1. Tier I: Weight of evidence of potential human carcinogenic 
    effects sufficient to derive a Tier I HCC shall generally include 
    human carcinogens, probable human carcinogens and can include, on a 
    case-by-case basis, possible human carcinogens if studies have been 
    well-conducted albeit based on limited evidence, when compared to 
    studies used in classifying human and probable human carcinogens. 
    The decision to use data on a possible human carcinogen for deriving 
    Tier I criteria shall be a case-by-case determination. In 
    determining whether to derive a Tier I HCC, additional evidence that 
    shall be considered includes but is not limited to available 
    information on mode of action, such as mutagenicity/genotoxicity 
    (determinations of whether the chemical interacts directly with 
    DNA), structure activity, and metabolism.
        2. Tier II: Weight of evidence of possible human carcinogenic 
    effects sufficient to derive a Tier II human cancer value shall 
    include those possible human carcinogens for which there are at a 
    minimum, data sufficient for quantitative risk assessment, but for 
    which data are inadequate for Tier I criterion development due to a 
    tumor response of marginal statistical significance or inability to 
    derive a strong dose-response relationship. In determining whether 
    to derive Tier II human cancer values, additional evidence that 
    shall be considered includes but is not limited to available 
    information on mode of action such as mutagenicity/genotoxicity 
    (determinations of whether the chemical interacts directly with 
    DNA), structure activity and metabolism. As with the use of data on 
    possible human carcinogens in developing Tier I criteria, the 
    decision to use data on possible human carcinogens to derive Tier II 
    values shall be made on a case-by-case basis.
        B. Noncarcinogens. All available toxicity data shall be 
    evaluated considering the full range of possible health effects of a 
    chemical, i.e., acute/subacute, chronic/subchronic and reproductive/
    developmental effects, in order to best describe the dose-response 
    relationship of the chemical, and to calculate human noncancer 
    criteria and values which will protect against the most sensitive 
    endpoint(s) of toxicity. Although it is desirable to have an 
    extensive database which considers a wide range of possible adverse 
    effects, this type of data exists for a very limited number of 
    chemicals. For many others, there is a range in quality and quantity 
    of data available. To assure minimum reliability of criteria and 
    values, it is necessary to establish a minimum database with which 
    to develop Tier I criteria or Tier II values. The following 
    represent the minimum data sets necessary for this procedure.
        1. Tier I: The minimum data set sufficient to derive a Tier I 
    human HNC shall include at least one well-conducted epidemiologic 
    study or animal study. A well-conducted epidemiologic study for a 
    Tier I HNC must quantify exposure level(s) and demonstrate positive 
    association between exposure to a chemical and adverse effect(s) in 
    humans. A well-conducted study in animals must demonstrate a dose 
    response relationship involving one or more critical effect(s) 
    biologically relevant to humans. (For example, study results from an 
    animal whose pharmacokinetics and toxicokinetics match those of a 
    human would be considered most biologically relevant.) Ideally, the 
    duration of a study should span multiple generations of exposed test 
    species or at least a major portion of the lifespan of one 
    generation. This type of data is currently very limited. By the use 
    of uncertainty adjustments, shorter term studies (such as 90-day 
    subchronic studies) with evaluation of more limited effect(s) may be 
    used to extrapolate to longer exposures or to account for a variety 
    of adverse effects. For Tier I criteria developed pursuant to this 
    procedure, such a limited study must be conducted for at least 90 
    days in rodents or 10 percent of the lifespan of other appropriate 
    test species and demonstrate a no observable adverse effect level 
    (NOAEL). Chronic studies of one year or longer in rodents or 50 
    percent of the lifespan or greater in other appropriate test species 
    that demonstrate a lowest observable adverse effect level (LOAEL) 
    may be sufficient for use in Tier I criterion derivation if the 
    effects observed at the LOAEL were relatively mild and reversible as 
    compared to [[Page 15408]] effects at higher doses. This does not 
    preclude the use of a LOAEL from a study (of chronic duration) with 
    only one or two doses if the effects observed appear minimal when 
    compared to effect levels observed at higher doses in other studies.
        2. Tier II: When the minimum data for deriving Tier I criteria 
    are not available to meet the Tier I data requirements, a more 
    limited database may be considered for deriving Tier II values. As 
    with Tier I criteria, all available data shall be considered and 
    ideally should address a range of adverse health effects with 
    exposure over a substantial portion of the lifespan (or multiple 
    generations) of the test species. When such data are lacking it may 
    be necessary to rely on less extensive data in order to establish a 
    Tier II value. With the use of appropriate uncertainty factors to 
    account for a less extensive database, the minimum data sufficient 
    to derive a Tier II value shall include a NOAEL from at least one 
    well-conducted short-term repeated dose study. This study shall be 
    of at least 28 days duration, in animals demonstrating a dose-
    response, and involving effects biologically relevant to humans. 
    Data from studies of longer duration (greater than 28 days) and 
    LOAELs from such studies (greater than 28 days) may be more 
    appropriate in some cases for derivation of Tier II values. Use of a 
    LOAEL should be based on consideration of the following information: 
    severity of effect, quality of the study and duration of the study.
        C. Bioaccumulation factors (BAFs).
        1. Tier I for Carcinogens and Noncarcinogens: To be considered a 
    Tier I cancer or noncancer human health criterion, along with 
    satisfying the minimum toxicity data requirements of sections II.A.1 
    and II.B.1 of this appendix, a chemical must have the following 
    minimum bioaccumulation data. For all organic chemicals either: (a) 
    a field-measured BAF; (b) a BAF derived using the BSAF methodology; 
    or (c) a chemical with a BAF less than 125 regardless of how the BAF 
    was derived. For all inorganic chemicals, including organometals 
    such as mercury, either: (a) a field-measured BAF or (b) a 
    laboratory-measured BCF.
        2. Tier II for Carcinogens and Noncarcinogens: A chemical is 
    considered a Tier II cancer or noncancer human health value if it 
    does not meet either the minimum toxicity data requirements of 
    sections II.A.1 and II.B.1 of this appendix or the minimum 
    bioaccumulation data requirements of section II.C.1 of this 
    appendix.
    
    III. Principles for Development of Tier I Criteria or Tier II Values
    
        The fundamental components of the procedure to calculate Tier I 
    criteria or Tier II values are the same. However, certain of the 
    aspects of the procedure designed to account for short-duration 
    studies or other limitations in data are more likely to be relevant 
    in deriving Tier II values than Tier I criteria.
        A. Carcinogens.
        1. A non-threshold mechanism of carcinogenesis shall be assumed 
    unless biological data adequately demonstrate the existence of a 
    threshold on a chemical-specific basis.
        2. All appropriate human epidemiologic data and animal cancer 
    bioassay data shall be considered. Data specific to an 
    environmentally appropriate route of exposure shall be used. Oral 
    exposure should be used preferentially over dermal and inhalation 
    since, in most cases, the exposure routes of greatest concern are 
    fish consumption and drinking water/incidental ingestion. The risk 
    associated dose shall be set at a level corresponding to an 
    incremental cancer risk of one in 100,000. If acceptable human 
    epidemiologic data are available for a chemical, it shall be used to 
    derive the risk associated dose. If acceptable human epidemiologic 
    data are not available, the risk associated dose shall be derived 
    from available animal bioassay data. Data from a species that is 
    considered most biologically relevant to humans (i.e., responds most 
    like humans) is preferred where all other considerations regarding 
    quality of data are equal. In the absence of data to distinguish the 
    most relevant species, data from the most sensitive species tested, 
    i.e., the species showing a carcinogenic effect at the lowest 
    administered dose, shall generally be used.
        3. When animal bioassay data are used and a non-threshold 
    mechanism of carcinogenicity is assumed, the data are fitted to a 
    linearized multistage computer model (e.g., Global '86 or equivalent 
    model). Global '86 is the linearized multistage model, derived by 
    Howe, Crump and Van Landingham (1986), which EPA uses to determine 
    cancer potencies. The upper-bound 95 percent confidence limit on 
    risk (or, the lower 95 percent confidence limit on dose) at the one 
    in 100,000 risk level shall be used to calculate a risk associated 
    dose (RAD). Other models, including modifications or variations of 
    the linear multistage model which are more appropriate to the 
    available data may be used where scientifically justified.
        4. If the duration of the study is significantly less than the 
    natural lifespan of the test animal, the slope may be adjusted on a 
    case-by-case basis to compensate for latent tumors which were not 
    expressed (e.g., U.S. EPA, 1980) In the absence of alternative 
    approaches which compensate for study durations significantly less 
    than lifetime, the permitting authority may use the process 
    described in the 1980 National Guidelines (see 45 FR 79352).
        5. A species scaling factor shall be used to account for 
    differences between test species and humans. It shall be assumed 
    that milligrams per surface area per day is an equivalent dose 
    between species (U.S. EPA, 1986). All doses presented in mg/kg 
    bodyweight will be converted to an equivalent surface area dose by 
    raising the mg/kg dose to the 2/3 power. However, if adequate 
    pharmacokinetic and metabolism studies are available, these data may 
    be factored into the adjustment for species differences on a case-
    by-case basis.
        6. Additional data selection and adjustment decisions must also 
    be made in the process of quantifying risk. Consideration must be 
    given to tumor selection for modeling, e.g., pooling estimates for 
    multiple tumor types and identifying and combining benign and 
    malignant tumors. All doses shall be adjusted to give an average 
    daily dose over the study duration. Adjustments in the rate of tumor 
    response must be made for early mortality in test species. The 
    goodness-of-fit of the model to the data must also be assessed.
        7. When a linear, non-threshold dose response relationship is 
    assumed, the RAD shall be calculated using the following equation:
    [GRAPHIC][TIFF OMITTED]TR23MR95.114
    
    
    Where:
    
    RAD=risk associated dose in milligrams of toxicant per kilogram body 
    weight per day (mg/kg/day).
    0.00001 (1 x 10-5)=incremental risk of developing cancer equal 
    to one in 100,000.
    q1*=slope factor (mg/kg/day)-1.
    
        8. If human epidemiologic data and/or other biological data 
    (animal) indicate that a chemical causes cancer via a threshold 
    mechanism, the risk associated dose may, on a case-by-case basis, be 
    calculated using a method which assumes a threshold mechanism is 
    operative.
        B. Noncarcinogens.
        1. Noncarcinogens shall generally be assumed to have a threshold 
    dose or concentration below which no adverse effects should be 
    observed. Therefore, the Tier I criterion or Tier II value is the 
    maximum water concentration of a substance at or below which a 
    lifetime exposure from drinking the water, consuming fish caught in 
    the water, and ingesting water as a result of participating in 
    water-related recreation activities is likely to be without 
    appreciable risk of deleterious effects.
        For some noncarcinogens, there may not be a threshold dose below 
    which no adverse effects should be observed. Chemicals acting as 
    genotoxic teratogens and germline mutagens are thought to possibly 
    produce reproductive and/or developmental effects via a genetically 
    linked mechanism which may have no threshold. Other chemicals also 
    may not demonstrate a threshold. Criteria for these types of 
    chemicals will be established on a case-by-case basis using 
    appropriate assumptions reflecting the likelihood that no threshold 
    exists.
        2. All appropriate human and animal toxicologic data shall be 
    reviewed and evaluated. To the maximum extent possible, data most 
    specific to the environmentally relevant route of exposure shall be 
    used. Oral exposure data should be used preferentially over dermal 
    and inhalation since, in most cases, the exposure routes of greatest 
    concern are fish consumption and drinking water/incidental 
    ingestion. When acceptable human data are not available (e.g., well-
    conducted epidemiologic studies), animal data from species most 
    biologically relevant to humans shall be used. In the absence of 
    data to distinguish the most relevant species, data from the most 
    sensitive animal species tested, i.e., the species showing a toxic 
    effect at the lowest administered dose (given a relevant route of 
    exposure), should generally be used. [[Page 15409]] 
        3. Minimum data requirements are specified in section II.B of 
    this appendix. The experimental exposure level representing the 
    highest level tested at which no adverse effects were demonstrated 
    (NOAEL) from studies satisfying the provisions of section II.B of 
    this appendix shall be used for criteria calculations. In the 
    absence of a NOAEL, the LOAEL from studies satisfying the provisions 
    of section II.B of this appendix may be used if it is based on 
    relatively mild and reversible effects.
        4. Uncertainty factors shall be used to account for the 
    uncertainties in predicting acceptable dose levels for the general 
    human population based upon experimental animal data or limited 
    human data.
        a. An uncertainty factor of 10 shall generally be used when 
    extrapolating from valid experimental results from studies on 
    prolonged exposure to average healthy humans. This 10-fold factor is 
    used to protect sensitive members of the human population.
        b. An uncertainty factor of 100 shall generally be used when 
    extrapolating from valid results of long-term studies on 
    experimental animals when results of studies of human exposure are 
    not available or are inadequate. In comparison to a, above, this 
    represents an additional 10-fold uncertainty factor in extrapolating 
    data from the average animal to the average human.
        c. An uncertainty factor of up to 1000 shall generally be used 
    when extrapolating from animal studies for which the exposure 
    duration is less than chronic, but greater than subchronic (e.g., 90 
    days or more in length), or when other significant deficiencies in 
    study quality are present, and when useful long-term human data are 
    not available. In comparison to b, above, this represents an 
    additional UF of up to 10-fold for less than chronic, but greater 
    than subchronic, studies.
        d. An UF of up to 3000 shall generally be used when 
    extrapolating from animal studies for which the exposure duration is 
    less than subchronic (e.g., 28 days). In comparison to b above, this 
    represents an additional UF of up to 30-fold for less than 
    subchronic studies (e.g., 28-day). The level of additional 
    uncertainty applied for less than chronic exposures depends on the 
    duration of the study used relative to the lifetime of the 
    experimental animal.
        e. An additional UF of between one and ten may be used when 
    deriving a criterion from a LOAEL. This UF accounts for the lack of 
    an identifiable NOAEL. The level of additional uncertainty applied 
    may depend upon the severity and the incidence of the observed 
    adverse effect.
        f. An additional UF of between one and ten may be applied when 
    there are limited effects data or incomplete sub-acute or chronic 
    toxicity data (e.g., reproductive/developmental data). The level of 
    quality and quantity of the experimental data available as well as 
    structure-activity relationships may be used to determine the factor 
    selected.
        g. When deriving an UF in developing a Tier I criterion or Tier 
    II value, the total uncertainty, as calculated following the 
    guidance of sections 4.a through f, cited above, shall not exceed 
    10,000 for Tier I criteria and 30,000 for Tier II values.
        5. All study results shall be converted, as necessary, to the 
    standard unit for acceptable daily exposure of milligrams of 
    toxicant per kilogram of body weight per day (mg/kg/day). Doses 
    shall be adjusted for continuous exposure (i.e., seven days/week, 24 
    hours/day, etc.).
        C. Criteria and Value Derivation.
        1. Standard Exposure Assumptions. The following represent the 
    standard exposure assumptions used to calculate Tier I criteria and 
    Tier II values for carcinogens and noncarcinogens. Higher levels of 
    exposure may be assumed by States and Tribes pursuant to Clean Water 
    Act (CWA) section 510, or where appropriate in deriving site-
    specific criteria pursuant to procedure 1 in appendix F to part 132.
        BW = body weight of an average human (BW = 70kg).
        WCd = per capita water consumption (both drinking and 
    incidental exposure) for surface waters classified as public water 
    supplies = two liters/day.
              --or--
        WCr = per capita incidental daily water ingestion for 
    surface waters not used as human drinking water sources = 0.01 
    liters/day.
        FC = per capita daily consumption of regionally caught 
    freshwater fish = 0.015kg/day (0.0036 kg/day for trophic level 3 and 
    0.0114 kg/day for trophic level 4).
        BAF = bioaccumulation factor for trophic level 3 and trophic 
    level 4, as derived using the BAF methodology in appendix B to part 
    132.
        2. Carcinogens. The Tier I human cancer criteria or Tier II 
    values shall be calculated as follows:
    [GRAPHIC][TIFF OMITTED]TR23MR95.115
    
    
    Where:
    
    HCV=Human Cancer Value in milligrams per liter (mg/L).
    RAD=Risk associated dose in milligrams toxicant per kilogram body 
    weight per day (mg/kg/day) that is associated with a lifetime 
    incremental cancer risk equal to one in 100,000.
    BW=weight of an average human (BW=70 kg).
    WCd=per capita water consumption (both drinking and incidental 
    exposure) for surface waters classified as public water supplies=two 
    liters/day.
          or
    WCr=per capita incidental daily water ingestion for surface 
    waters not used as human drinking water sources=0.01 liters/day.
    FCTL3=mean consumption of trophic level 3 of regionally caught 
    freshwater fish=0.0036 kg/day.
    FCTL4=mean consumption of trophic level 4 of regionally caught 
    freshwater fish=0.0114 kg/day.
    BAFHHTL3=bioaccumulation factor for trophic level 3 fish, 
    as derived using the BAF methodology in appendix B to part 132.
    BAFHHTL4=bioaccumulation factor for trophic level 4 fish, 
    as derived using the BAF methodology in appendix B to part 132.
    
        3. Noncarcinogens. The Tier I human noncancer criteria or Tier 
    II values shall be calculated as follows:
    [GRAPHIC][TIFF OMITTED]TR23MR95.116
    
    
    Where:
    
    HNV=Human noncancer value in milligrams per liter (mg/L).
    ADE=Acceptable daily exposure in milligrams toxicant per kilogram 
    body weight per day (mg/kg/day).
    RSC=Relative source contribution factor of 0.8. An RSC derived from 
    actual exposure data may be developed using the methodology outlined 
    by the 1980 National Guidelines (see 45 FR 79354).
    BW=weight of an average human (BW=70 kg).
    WCd=per capita water consumption (both drinking and incidental 
    exposure) for surface waters classified as public water supplies=two 
    liters/day.
          or
    WCr=per capita incidental daily water ingestion for surface 
    waters not used as human drinking water sources=0.01 liters/
    day. [[Page 15410]] 
    FCTL3=mean consumption of trophic level 3 fish by regional 
    sport fishers of regionally caught freshwater fish=0.0036 kg/day.
    FCTL4=mean consumption of trophic level 4 fish by regional 
    sport fishers of regionally caught freshwater fish=0.0114 kg/day.
    BAFHHTL3=human health bioaccumulation factor for edible 
    portion of trophic level 3 fish, as derived using the BAF 
    methodology in appendix B to part 132.
    BAFHHTL4=human health bioaccumulation factor for edible 
    portion of trophic level 4 fish, as derived using the BAF 
    methodology in appendix B to part 132.
    
    IV. References
    
        A. Howe, R.B., K.S. Crump and C. Van Landingham. 1986. Computer 
    Program to Extrapolate Quantitative Animal Toxicity Data to Low 
    Doses. Prepared for EPA under subcontract #2-251U-2745 to Research 
    Triangle Institute.
        B. U.S. Environmental Protection Agency. 1980. Water Quality 
    Criteria Availability, Appendix C Guidelines and Methodology Used in 
    the Preparation of Health Effects Assessment Chapters of the Consent 
    Decree Water Quality Criteria Documents. Available from U.S. 
    Environmental Protection Agency, Office of Water Resource Center 
    (WH-550A), 401 M St., SW., Washington, DC 20460.
        C. U.S. Environmental Protection Agency. 1986. Guidelines for 
    Carcinogen Risk Assessment. Available from U.S. Environmental 
    Protection Agency, Office of Water Resource Center (WH-550A), 401 M 
    St., SW., Washington, DC 20460.
    
    Appendix D to Part 132--Great Lakes Water Quality Initiative 
    Methodology for the Development of Wildlife Criteria
    
        Great Lakes States and Tribes shall adopt provisions consistent 
    with (as protective as) this appendix.
    
    I. Introduction
    
        A. A Great Lakes Water Quality Wildlife Criterion (GLWC) is the 
    concentration of a substance which is likely to, if not exceeded, 
    protect avian and mammalian wildlife populations inhabiting the 
    Great Lakes basin from adverse effects resulting from the ingestion 
    of water and aquatic prey taken from surface waters of the Great 
    Lakes System. These criteria are based on existing toxicological 
    studies of the substance of concern and quantitative information 
    about the exposure of wildlife species to the substance (i.e., food 
    and water consumption rates). Since toxicological and exposure data 
    for individual wildlife species are limited, a GLWC is derived using 
    a methodology similar to that used to derive noncancer human health 
    criteria (Barnes and Dourson, 1988; NAS, 1977; NAS, 1980; U.S. EPA, 
    1980). Separate avian and mammalian values are developed using 
    taxonomic class-specific toxicity data and exposure data for five 
    representative Great Lakes basin wildlife species. The wildlife 
    species selected are representative of avian and mammalian species 
    resident in the Great Lakes basin which are likely to experience the 
    highest exposures to bioaccumulative contaminants through the 
    aquatic food web; they are the bald eagle, herring gull, belted 
    kingfisher, mink, and river otter.
        B. This appendix establishes a methodology which is required 
    when developing Tier I wildlife criteria for bioaccumulative 
    chemicals of concern (BCCs). The use of the equation provided in the 
    methodology is encouraged, but not required, for the development of 
    Tier I criteria or Tier II values for pollutants other than those 
    identified in Table 6-A for which Tier I criteria or Tier II values 
    are determined to be necessary for the protection of wildlife in the 
    Great Lakes basin. A discussion of the methodology for deriving Tier 
    II values can be found in the Great Lakes Water Quality Initiative 
    Technical Support Document for Wildlife Criteria (Wildlife TSD).
        C. In the event that this methodology is used to develop 
    criteria for pollutants other than BCCs, or in the event that the 
    Tier II methodology described in the Wildlife TSD is used to derive 
    Tier II values, the methodology for deriving bioaccumulation factors 
    under appendix B to part 132 must be used in either derivation. For 
    chemicals which do not biomagnify to the extent of BCCs, it may be 
    appropriate to select different representative species which are 
    better examples of species with the highest exposures for the given 
    chemical. The equation presented in this methodology, however, is 
    still encouraged. In addition, procedure 1 of appendix F of this 
    part describes the procedures for calculating site-specific wildlife 
    criteria.
        D. The term ``wildlife value'' (WV) is used to denote the value 
    for each representative species which results from using the 
    equation presented below, the value obtained from averaging species 
    values within a class, or any value derived from application of the 
    site-specific procedure provided in procedure 1 of appendix F of 
    this part. The WVs calculated for the representative species are 
    used to calculate taxonomic class-specific WVs. The WV is the 
    concentration of a substance which, if not exceeded, should better 
    protect the taxon in question.
        E. ``Tier I wildlife criterion,'' or ``Tier I criterion'' is 
    used to denote the number derived from data meeting the Tier I 
    minimum database requirements, and which will be protective of the 
    two classes of wildlife. It is synonymous with the term ``GLWC,'' 
    and the two are used interchangeably.
    
    II. Calculation of Wildlife Values for Tier I Criteria
    
        Table 4 of Part 132 and Table D-1 of this appendix contain 
    criteria calculated by EPA using the methodology provided below.
        A. Equation for Avian and Mammalian Wildlife Values. Tier I 
    wildlife values for the pollutants designated BCCs pursuant to part 
    132 are to be calculated using the equation presented below.
    [GRAPHIC][TIFF OMITTED]TR23MR95.117
    
    
    Where:
    WV=Wildlife Value in milligrams of substance per liter (mg/L).
    TD=Test Dose (TD) in milligrams of substance per kilograms per day 
    (mg/kg-d) for the test species. This shall be either a NOAEL or a 
    LOAEL.
    UFA=Uncertainty Factor (UF) for extrapolating toxicity data 
    across species (unitless). A species-specific UF shall be selected 
    and applied to each representative species, consistent with the 
    equation.
    UFS=UF for extrapolating from subchronic to chronic exposures 
    (unitless).
    UFL=UF for LOAEL to NOAEL extrapolations (unitless).
    Wt=Average weight in kilograms (kg) for the representative species.
    W=Average daily volume of water consumed in liters per day (L/d) by 
    the representative species.
    FTLi=Average daily amount of food consumed from trophic level i 
    in kilograms per day (kg/d) by the representative species.
    BAFWLTLi=Bioaccumulation factor (BAF) for wildlife food in 
    trophic level i in liters per kilogram (L/kg), developed using the 
    BAF methodology in appendix B to part 132, Methodology for 
    Development of Bioaccumulation Factors. For consumption of 
    piscivorous birds by other birds (e.g., herring gull by eagles), the 
    BAF is derived by multiplying the trophic level 3 BAF for fish by a 
    biomagnification factor to account for the biomagnification from 
    fish to the consumed birds.
    
        B. Identification of Representative Species for Protection. For 
    bioaccumulative chemicals, piscivorous species are identified as the 
    focus of concern for wildlife criteria development in the Great 
    Lakes. An analysis of known or estimated exposure components for 
    avian and mammalian wildlife species is presented in the Wildlife 
    TSD. This analysis identifies three avian species (eagle, kingfisher 
    and herring gull) and two mammalian species (mink and otter) as 
    representative species for protection. The TD obtained from toxicity 
    data for each taxonomic class is used to calculate WVs for each of 
    the five representative species.
        C. Calculation of Avian and Mammalian Wildlife Values and GLWC 
    Derivation. The avian WV is the geometric mean of the WVs calculated 
    for the three representative avian species. The mammalian WV is the 
    geometric mean of the WVs calculated for the two representative 
    mammalian species. The lower of the mammalian and avian WVs must be 
    selected as the GLWC.
    
    III. Parameters of the Effect Component of the Wildlife Criteria 
    Methodology
    
        A. Definitions. The following definitions provide additional 
    specificity and guidance in the evaluation of toxicity data and the 
    application of this methodology.
        Acceptable endpoints. For the purpose of wildlife criteria 
    derivation, acceptable subchronic and chronic endpoints are those 
    which affect reproductive or developmental success, organismal 
    viability or growth, or any other endpoint which is, or is directly 
    related to, parameters that influence population dynamics. 
    [[Page 15411]] 
        Chronic effect. An adverse effect that is measured by assessing 
    an acceptable endpoint, and results from continual exposure over 
    several generations, or at least over a significant part of the test 
    species' projected life span or life stage.
        Lowest-observed-adverse-effect-level (LOAEL). The lowest tested 
    dose or concentration of a substance which resulted in an observed 
    adverse effect in exposed test organisms when all higher doses or 
    concentrations resulted in the same or more severe effects.
        No-observed-adverse-effect-level (NOAEL). The highest tested 
    dose or concentration of a substance which resulted in no observed 
    adverse effect in exposed test organisms where higher doses or 
    concentrations resulted in an adverse effect.
        Subchronic effect. An adverse effect, measured by assessing an 
    acceptable endpoint, resulting from continual exposure for a period 
    of time less than that deemed necessary for a chronic test.
        B. Minimum Toxicity Database for Tier I Criteria Development. A 
    TD value is required for criterion calculation. To derive a Tier I 
    criterion for wildlife, the data set shall provide enough data to 
    generate a subchronic or chronic dose-response curve for any given 
    substance for both mammalian and avian species. In reviewing the 
    toxicity data available which meet the minimum data requirements for 
    each taxonomic class, the following order of preference shall be 
    applied to select the appropriate TD to be used for calculation of 
    individual WVs. Data from peer-reviewed field studies of wildlife 
    species take precedence over other types of studies, where such 
    studies are of adequate quality. An acceptable field study must be 
    of subchronic or chronic duration, provide a defensible, chemical-
    specific dose-response curve in which cause and effect are clearly 
    established, and assess acceptable endpoints as defined in this 
    document. When acceptable wildlife field studies are not available, 
    or determined to be of inadequate quality, the needed toxicity 
    information may come from peer-reviewed laboratory studies. When 
    laboratory studies are used, preference shall be given to laboratory 
    studies with wildlife species over traditional laboratory animals to 
    reduce uncertainties in making interspecies extrapolations. All 
    available laboratory data and field studies shall be reviewed to 
    corroborate the final GLWC, to assess the reasonableness of the 
    toxicity value used, and to assess the appropriateness of any UFs 
    which are applied. When evaluating the studies from which a test 
    dose is derived in general, the following requirements must be met:
        1. The mammalian data must come from at least one well-conducted 
    study of 90 days or greater designed to observe subchronic or 
    chronic effects as defined in this document.
        2. The avian data must come from at least one well-conducted 
    study of 70 days or greater designed to observe subchronic or 
    chronic effects as defined in this document.
        3. In reviewing the studies from which a TD is derived for use 
    in calculating a WV, studies involving exposure routes other than 
    oral may be considered only when an equivalent oral daily dose can 
    be estimated and technically justified because the criteria 
    calculations are based on an oral route of exposure.
        4. In assessing the studies which meet the minimum data 
    requirements, preference should be given to studies which assess 
    effects on developmental or reproductive endpoints because, in 
    general, these are more important endpoints in ensuring that a 
    population's productivity is maintained. The Wildlife TSD provides 
    additional discussion on the selection of an appropriate toxicity 
    study.
        C. Selection of TD Data. In selecting data to be used in the 
    derivation of WVs, the evaluation of acceptable endpoints, as 
    defined in Section III.A of this appendix, will be the primary 
    selection criterion. All data not part of the selected subset may be 
    used to assess the reasonableness of the toxicity value and the 
    appropriateness of the Ufs which are applied.
        1. If more than one TD value is available within a taxonomic 
    class, based on different endpoints of toxicity, that TD, which is 
    likely to reflect best potential impacts to wildlife populations 
    through resultant changes in mortality or fecundity rates, shall be 
    used for the calculation of WVs.
        2. If more than one TD is available within a taxonomic class, 
    based on the same endpoint of toxicity, the TD from the most 
    sensitive species shall be used.
        3. If more than one TD based on the same endpoint of toxicity is 
    available for a given species, the TD for that species shall be 
    calculated using the geometric mean of those TDs.
        D. Exposure Assumptions in the Determination of the TD. 1. In 
    those cases in which a TD is available in units other than 
    milligrams of substance per kilograms per day (mg/kg/d), the 
    following procedures shall be used to convert the TD to the 
    appropriate units prior to calculating a WV.
        2. If the TD is given in milligrams of toxicant per liter of 
    water consumed by the test animals (mg/L), the TD shall be 
    multiplied by the daily average volume of water consumed by the test 
    animals in liters per day (L/d) and divided by the average weight of 
    the test animals in kilograms (kg).
        3. If the TD is given in milligrams of toxicant per kilogram of 
    food consumed by the test animals (mg/kg), the TD shall be 
    multiplied by the average amount of food in kilograms consumed daily 
    by the test animals (kg/d) and divided by the average weight of the 
    test animals in kilograms (kg).
        E. Drinking and Feeding Rates. 1. When drinking and feeding 
    rates and body weight are needed to express the TD in milligrams of 
    substance per kilograms per day (mg/kg/d), they are obtained from 
    the study from which the TD was derived. If not already determined, 
    body weight, and drinking and feeding rates are to be converted to a 
    wet weight basis.
        2. If the study does not provide the needed values, the values 
    shall be determined from appropriate scientific literature. For 
    studies done with domestic laboratory animals, either the Registry 
    of Toxic Effects of Chemical Substances (National Institute for 
    Occupational Safety and Health, the latest edition, Cincinnati, OH), 
    or Recommendations for and Documentation of Biological Values for 
    Use in Risk Assessment (U.S. EPA, 1988) should be consulted. When 
    these references do not contain exposure information for the species 
    used in a given study, either the allometric equations from Calder 
    and Braun (1983) and Nagy (1987), which are presented below, or the 
    exposure estimation methods presented in Chapter 4 of the Wildlife 
    Exposure Factors Handbook (U.S. EPA, 1993), should be applied to 
    approximate the needed feeding or drinking rates. Additional 
    discussion and recommendations are provided in the Wildlife TSD. The 
    choice of the methods described above is at the discretion of the 
    State or Tribe.
        3. For mammalian species, the general allometric equations are:
    
        a. F = 0.0687  x  (Wt)0.82
    
    Where:
    
    F = Feeding rate of mammalian species in kilograms per day (kg/d) 
    dry weight.
    Wt = Average weight in kilograms (kg) of the test animals.
    
        b. W = 0.099  x  (Wt)0.90
    
    Where:
    
    W = Drinking rate of mammalian species in liters per day (L/d).
     Wt = Average weight in kilograms (kg) of the test animals.
        4. For avian species, the general allometric equations are:
    
        a. F = 0.0582 (Wt)0.65
    
    Where:
    
    F = Feeding rate of avian species in kilograms per day (kg/d) dry 
    weight.
    Wt = Average weight in kilograms (kg) of the test animals.
    
        b. W = 0.059  x  (Wt)0.67
    
    Where:
    
    W = Drinking rate of avian species in liters per day (L/d).
    Wt = Average weight in kilograms (kg) of the test animals.
        F. LOAEL to NOAEL Extrapolations (UFL). In those cases in 
    which a NOAEL is unavailable as the TD and a LOAEL is available, the 
    LOAEL may be used to estimate the NOAEL. If used, the LOAEL shall be 
    divided by an UF to estimate a NOAEL for use in deriving WVs. The 
    value of the UF shall not be less than one and should not exceed 10, 
    depending on the dose-response curve and any other available data, 
    and is represented by UFL in the equation expressed in Section 
    II.A of this appendix. Guidance for selecting an appropriate 
    UFL, based on a review of available wildlife toxicity data, is 
    available in the Wildlife TSD.
        G. Subchronic to Chronic Extrapolations (USS). In instances 
    where only subchronic data are available, the TD may be derived from 
    subchronic data. In such cases, the TD shall be divided by an UF to 
    extrapolate from subchronic to chronic levels. The value of the UF 
    shall not be less than one and should not exceed 10, and is 
    represented by UFS in the equation expressed in Section II.A of 
    this appendix. This factor is to be used when assessing highly 
    bioaccumulative substances where toxicokinetic considerations 
    suggest that a bioassay of limited length 
    [[Page 15412]] underestimates chronic effects. Guidance for 
    selecting an appropriate UFS, based on a review of available 
    wildlife toxicity data, is available in the Wildlife TSD.
        H. Interspecies Extrapolations (UFA). 1. The selection of 
    the UFA shall be based on the available toxicological data and 
    on available data concerning the physicochemical, toxicokinetic, and 
    toxicodynamic properties of the substance in question and the amount 
    and quality of available data. This value is an UF that is intended 
    to account for differences in toxicological sensitivity among 
    species. Guidance for selecting an appropriate UFA, based on a 
    review of available wildlife toxicity data, is available in the 
    Wildlife TSD. Additional discussion of an interspecies UF located in 
    appendix A to the Great Lakes Water Quality Initiative Technical 
    Support Document for Human Health Criteria may be useful in 
    determining the appropriate value for UFA.
        2. For the derivation of Tier I criteria, a UFA shall not 
    be less than one and should not exceed 100, and shall be applied to 
    each of the five representative species, based on existing data and 
    best professional judgment. The value of UFA may differ for 
    each of the representative species.
        3. For Tier I wildlife criteria, the UFA shall be used only 
    for extrapolating toxicity data across species within a taxonomic 
    class, except as provided below. The Tier I UFA is not intended 
    for interclass extrapolations because of the poorly defined 
    comparative toxicokinetic and toxicodynamic parameters between 
    mammals and birds. However, an interclass extrapolation employing a 
    UFA may be used for a given chemical if it can be supported by 
    a validated biologically-based dose-response model or by an analysis 
    of interclass toxicological data, considering acceptable endpoints, 
    for a chemical analog that acts under the same mode of toxic action.
    
    IV. Parameters of the Exposure Component of the Wildlife Criteria 
    Methodology
    
        A. Drinking and Feeding Rates of Representative Species. The 
    body weights (Wt), feeding rates (FTli), drinking rates (W), 
    and trophic level dietary composition (as food ingestion rate and 
    percent in diet) for each of the five representative species are 
    presented in Table D-2 of this appendix. Guidance on incorporating 
    the non-aquatic portion of the bald eagle and mink diets in the 
    criteria calculations is available in the Wildlife TSD.
        B. BAFs. The Methodology for Development of Bioaccumulation 
    Factors is presented in appendix B to part 132. Trophic level 3 and 
    4 BAFs are used to derive Wvs because these are the trophic levels 
    at which the representative species feed.
    
    V. References
    
        A. Barnes, D.G. and M. Dourson. 1988. Reference Dose (RfD): 
    Description and Use in Health Risk Assessments. Regul. Toxicol. 
    Pharmacol. 8:471-486.
        B. Calder III, W.A. and E.J. Braun. 1983. Scaling of Osmotic 
    Regulation in Mammals and Birds. American Journal of Physiology. 
    244:601-606.
        C. Nagy, K.A. 1987. Field Metabolic Rate and Food Requirement 
    Scaling in Mammals and Birds. Ecological Monographs. 57(2):111-128.
        D. National Academy of Sciences. 1977. Chemical Contaminants: 
    Safety and Risk Assessment, in Drinking Water and Health, Volume 1. 
    National Academy Press.
        E. National Academy of Sciences. 1980. Problems of Risk 
    Estimation, in Drinking Water and Health, Volume 3. National Academy 
    Press.
        F. National Institute for Occupational Safety and Health. Latest 
    edition. Registry of Toxic Effects of Chemical Substances. Division 
    of Standards Development and Technology Transfer. (Available only on 
    microfiche or as an electronic database.)
        G. U.S. EPA. 1980. Appendix C. Guidelines and Methodology Used 
    in the Preparation of Health Effect Assessment Chapters of the 
    Consent Decree Water Criteria Documents, pp. 79347-79357 in Water 
    Quality Criteria Documents; Availability. Available from U.S. 
    Environmental Protection Agency, Office of Water Resource Center 
    (WH-550A), 401 M St. SW, Washington, DC 20460.
        H. U.S. EPA. 1988. Recommendations for, and documentation of, 
    biological values for use in risk assessment. NTIS-PB88-179874.
        I. U.S. EPA. 1993. Wildlife Exposure Factors Handbook, Volumes I 
    and II. EPA/600/R-93/187a and b.
    
    Tables to Appendix D to Part 132
    
                Table D-1.--Tier I Great Lakes Wildlife Criteria            
    ------------------------------------------------------------------------
                                                                  Criterion 
                             Substance                          (g/
                                                                     L)     
    ------------------------------------------------------------------------
    DDT & Metabolites.........................................  1.1E-5      
    Mercury...................................................  1.3E-3      
    PCBs (total)..............................................  7.4E-5      
    2,3,7,8-TCDD..............................................  3.1E-9      
    ------------------------------------------------------------------------
    
    
              Table D-2.--Exposure Parameters for the Five Representative Species Identified for Protection         
    ----------------------------------------------------------------------------------------------------------------
                                                 Water                                                              
                                  Adult body   ingestion    Food ingestion rate of prey     Trophic level of prey   
           Species (units)          weight      rate (L/    in each trophic level (kg/        (percent of diet)     
                                     (kg)         day)                 day)                                         
    ----------------------------------------------------------------------------------------------------------------
    Mink........................        0.80        0.081  TL3: 0.159; Other: 0.0177...  TL3: 90; Other: 10.        
    Otter.......................        7.4         0.600  TL3: 0.977; TL4: 0.244......  TL3: 80; TL4: 20.          
    Kingfisher..................        0.15        0.017  TL3: 0.0672.................  TL3: 100.                  
    Herring gull................        1.1         0.063  TL3: 0.192; TL4: 0.0480.....  Fish: 90--TL3: 80; TL4: 20.
                                                           Other: 0.0267...............  Other: 10.                 
    Bald eagle..................        4.6         0.160  TL3: 0.371; TL4: 0.0929.....  Fish: 92--TL3: 80; TL4: 20.
                                                           PB: 00283; Other: 0.0121....  Birds: 8--PB: 70; non-     
                                                                                          aquatic: 30.              
    ----------------------------------------------------------------------------------------------------------------
    Note: TL3=trophic level three fish;  TL4=trophic level four fish;  PB=piscivorous birds;  Other=non-aquatic     
      birds and mammals.                                                                                            
    
    Appendix E to Part 132--Great Lakes Water Quality Initiative 
    Antidegradation Policy
    
        Great Lakes States and Tribes shall adopt provisions consistent 
    with (as protective as) appendix E to part 132.
        The State or Tribe shall adopt an antidegradation standard 
    applicable to all waters of the Great Lakes System and identify the 
    methods for implementing such a standard. Consistent with 40 CFR 
    131.12, an acceptable antidegradation standard and implementation 
    procedure are required elements of a State's or Tribe's water 
    quality standards program. Consistent with 40 CFR 131.6, a complete 
    water quality standards submission needs to include both an 
    antidegradation standard and antidegradation implementation 
    procedures. At a minimum, States and Tribes shall adopt provisions 
    in their antidegradation standard and implementation methods 
    consistent with sections I, II, III and IV of this appendix, 
    applicable to pollutants identified as bioaccumulative chemicals of 
    concern (BCCs).
    
    I. Antidegradation Standard
    
        This antidegradation standard shall be applicable to any action 
    or activity by any source, point or nonpoint, of pollutants that is 
    anticipated to result in an increased loading of BCCs to surface 
    waters of the Great Lakes System and for which independent 
    regulatory authority exists requiring compliance with water quality 
    standards. Pursuant to this standard:
        A. Existing instream water uses, as defined pursuant to 40 CFR 
    131, and the level of water quality necessary to protect existing 
    uses shall be maintained and protected. Where designated uses of the 
    waterbody are impaired, there shall be no lowering of the water 
    quality with respect to the pollutant or pollutants which are 
    causing the impairment;
        B. Where, for any parameter, the quality of the waters exceed 
    levels necessary to support the propagation of fish, shellfish, and 
    wildlife and recreation in and on the waters, that water shall be 
    considered high quality for that parameter consistent with the 
    definition of high quality water found at section II.A of this 
    appendix and that quality [[Page 15413]] shall be maintained and 
    protected unless the State or Tribe finds, after full satisfaction 
    of intergovernmental coordination and public participation 
    provisions of the State's or Tribe's continuing planning process, 
    that allowing lower water quality is necessary to accommodate 
    important economic or social development in the area in which the 
    waters are located. In allowing such degradation, the State or Tribe 
    shall assure water quality adequate to protect existing uses fully. 
    Further, the State or Tribe shall assure that there shall be 
    achieved the highest statutory and regulatory requirements for all 
    new and existing point sources and all cost-effective and reasonable 
    best management practices for nonpoint source control. The State or 
    Tribe shall utilize the Antidegradation Implementation Procedures 
    adopted pursuant to the requirements of this regulation in 
    determining if any lowering of water quality will be allowed;
        C. Where high quality waters constitute an outstanding national 
    resource, such as waters of national and State parks and wildlife 
    refuges and waters of exceptional recreational or ecological 
    significance, that water quality shall be maintained and protected; 
    and
        D. In those cases where the potential lowering of water quality 
    is associated with a thermal discharge, the decision to allow such 
    degradation shall be consistent with section 316 of the Clean Water 
    Act (CWA).
    
    II. Antidegradation Implementation Procedures
    
        A. Definitions.
        Control Document. Any authorization issued by a State, Tribal or 
    Federal agency to any source of pollutants to waters under its 
    jurisdiction that specifies conditions under which the source is 
    allowed to operate.
        High quality waters. High quality waters are water bodies in 
    which, on a parameter by parameter basis, the quality of the waters 
    exceeds levels necessary to support propagation of fish, shellfish, 
    and wildlife and recreation in and on the water.
        Lake Superior Basin--Outstanding International Resource Waters. 
    Those waters designated as such by a Tribe or State consistent with 
    the September 1991 Bi-National Program to Restore and Protect the 
    Lake Superior Basin. The purpose of such designations shall be to 
    ensure that any new or increased discharges of Lake Superior 
    bioaccumulative substances of immediate concern are subject to best 
    technology in process and treatment requirements.
        Lake Superior Basin--Outstanding National Resource Waters. Those 
    waters designated as such by a Tribe or State consistent with the 
    September 1991 Bi-National Program to Restore and Protect the Lake 
    Superior Basin. The purpose of such designations shall be to 
    prohibit new or increased discharges of Lake Superior 
    bioaccumulative substances of immediate concern from point sources 
    in these areas.
        Lake Superior bioaccumulative substances of immediate concern. A 
    list of substances identified in the September 1991 Bi-National 
    Program to Restore and Protect the Lake Superior Basin. They 
    include: 2, 3, 7, 8-TCDD; octachlorostyrene; hexachlorobenzene; 
    chlordane; DDT, DDE, and other metabolites; toxaphene; PCBs; and 
    mercury. Other chemicals may be added to the list following States' 
    or Tribes' assessments of environmental effects and impacts and 
    after public review and comment.
        Outstanding National Resource Waters. Those waters designated as 
    such by a Tribe or State. The State or Tribal designation shall 
    describe the quality of such waters to serve as the benchmark of the 
    water quality that shall be maintained and protected. Waters that 
    may be considered for designation as Outstanding National Resource 
    Waters include, but are not limited to, water bodies that are 
    recognized as:
        Important because of protection through official action, such as 
    Federal or State law, Presidential or secretarial action, 
    international treaty, or interstate compact;
        Having exceptional recreational significance;
        Having exceptional ecological significance;
        Having other special environmental, recreational, or ecological 
    attributes; or waters whose designation as Outstanding National 
    Resource Waters is reasonably necessary for the protection of other 
    waters so designated.
        Significant Lowering of Water Quality. A significant lowering of 
    water quality occurs when there is a new or increased loading of any 
    BCC from any regulated existing or new facility, either point source 
    or nonpoint source for which there is a control document or 
    reviewable action, as a result of any activity including, but not 
    limited to:
        (1) Construction of a new regulated facility or modification of 
    an existing regulated facility such that a new or modified control 
    document is required;
        (2) Modification of an existing regulated facility operating 
    under a current control document such that the production capacity 
    of the facility is increased;
        (3) Addition of a new source of untreated or pretreated effluent 
    containing or expected to contain any BCC to an existing wastewater 
    treatment works, whether public or private;
        (4) A request for an increased limit in an applicable control 
    document;
        (5) Other deliberate activities that, based on the information 
    available, could be reasonably expected to result in an increased 
    loading of any BCC to any waters of the Great Lakes System.
        b. Notwithstanding the above, changes in loadings of any BCC 
    within the existing capacity and processes, and that are covered by 
    the existing applicable control document, are not subject to an 
    antidegradation review. These changes include, but are not limited 
    to:
        (1) Normal operational variability;
        (2) Changes in intake water pollutants;
        (3) Increasing the production hours of the facility, (e.g., 
    adding a second shift); or
        (4) Increasing the rate of production.
        C. Also, excluded from an antidegradation review are new 
    effluent limits based on improved monitoring data or new water 
    quality criteria or values that are not a result of changes in 
    pollutant loading.
        B. For all waters, the Director shall ensure that the level of 
    water quality necessary to protect existing uses is maintained. In 
    order to achieve this requirement, and consistent with 40 CFR 
    131.10, water quality standards use designations must include all 
    existing uses. Controls shall be established as necessary on point 
    and nonpoint sources of pollutants to ensure that the criteria 
    applicable to the designated use are achieved in the water and that 
    any designated use of a downstream water is protected. Where water 
    quality does not support the designated uses of a waterbody or 
    ambient pollutant concentrations exceed water quality criteria 
    applicable to that waterbody, the Director shall not allow a 
    lowering of water quality for the pollutant or pollutants preventing 
    the attainment of such uses or exceeding such criteria.
        C. For Outstanding National Resource Waters:
        1. The Director shall ensure, through the application of 
    appropriate controls on pollutant sources, that water quality is 
    maintained and protected.
        2. Exception. A short-term, temporary (i.e., weeks or months) 
    lowering of water quality may be permitted by the Director.
        D. For high quality waters, the Director shall ensure that no 
    action resulting in a lowering of water quality occurs unless an 
    antidegradation demonstration has been completed pursuant to section 
    III of this appendix and the information thus provided is determined 
    by the Director pursuant to section IV of this appendix to 
    adequately support the lowering of water quality.
        1. The Director shall establish conditions in the control 
    document applicable to the regulated facility that prohibit the 
    regulated facility from undertaking any deliberate action, such that 
    there would be an increase in the rate of mass loading of any BCC, 
    unless an antidegradation demonstration is provided to the Director 
    and approved pursuant to section IV of this appendix prior to 
    commencement of the action. Imposition of limits due to improved 
    monitoring data or new water quality criteria or values, or changes 
    in loadings of any BCC within the existing capacity and processes, 
    and that are covered by the existing applicable control document, 
    are not subject to an antidegradation review.
        2. For BCCs known or believed to be present in a discharge, from 
    a point or nonpoint source, a monitoring requirement shall be 
    included in the control document. The control document shall also 
    include a provision requiring the source to notify the Director or 
    any increased loadings. Upon notification, the Director shall 
    require actions as necessary to reduce or eliminate the increased 
    loading.
        3. Fact Sheets prepared pursuant to 40 CFR 124.8 and 124.56 
    shall reflect any conditions developed under sections II.D.1 or 
    II.D.2 of this appendix and included in a permit.
        E. Special Provisions for Lake Superior.The following conditions 
    apply in addition to those specified in section II.B through II.C of 
    this appendix for waters of Lake Superior so designated.
        1. A State or Tribe may designate certain specified areas of the 
    Lake Superior Basin as Lake Superior Basin--Outstanding National 
    Resource Waters for the purpose of prohibiting the new or increased 
    discharge of [[Page 15414]] Lake Superior bioaccumulative substances 
    of immediate concern from point sources in these areas.
        2. States and Tribes may designate all waters of the Lake 
    Superior Basin as Outstanding International Resource Waters for the 
    purpose of restricting the increased discharge of Lake Superior 
    bioaccumulative substances of immediate concern from point sources 
    consistent with the requirements of sections III.C and IV.B of this 
    appendix.
        F. Exemptions. Except as the Director may determine on a case-
    by-case basis that the application of these procedures is required 
    to adequately protect water quality, or as the affected waterbody is 
    an Outstanding National Resource Water as defined in section II.A of 
    this appendix, the procedures in this part do not apply to:
        1. Short-term, temporary (i.e., weeks or months) lowering of 
    water quality;
        2. Bypasses that are not prohibited at 40 CFR 122.41(m); and
        3. Response actions pursuant to the Comprehensive Environmental 
    Response, Compensation and Liability Act (CERCLA), as amended, or 
    similar Federal, State or Tribal authorities, undertaken to 
    alleviate a release into the environment of hazardous substances, 
    pollutants or contaminants which may pose an imminent and 
    substantial danger to public health or welfare.
    
    III. Antidegradation Demonstration
    
        Any entity seeking to lower water quality in a high quality 
    water or create a new or increased discharge of Lake Superior 
    bioaccumulative substances of immediate concern in a Lake Superior 
    Outstanding International Resource Water must first, as required by 
    sections II.D or II.E.2 of this appendix, submit an antidegradation 
    demonstration for consideration by the Director. States and Tribes 
    should tailor the level of detail and documentation in 
    antidegradation reviews, to the specific circumstances encountered. 
    The antidegradation demonstration shall include the following:
        A. Pollution Prevention Alternatives Analysis. Identify any 
    cost-effective pollution prevention alternatives and techniques that 
    are available to the entity, that would eliminate or significantly 
    reduce the extent to which the increased loading results in a 
    lowering of water quality.
        B. Alternative or Enhanced Treatment Analysis. Identify 
    alternative or enhanced treatment techniques that are available to 
    the entity that would eliminate the lowering of water quality and 
    their costs relative to the cost of treatment necessary to achieve 
    applicable effluent limitations.
        C. Lake Superior. If the States or Tribes designate the waters 
    of Lake Superior as Outstanding International Resource Waters 
    pursuant to section II.E.2 of this appendix, then any entity 
    proposing a new or increased discharge of any Lake Superior 
    bioaccumulative substance of immediate concern to the Lake Superior 
    Basin shall identify the best technology in process and treatment to 
    eliminate or reduce the extent of the lowering of water quality. In 
    this case, the requirements in section III.B of this appendix do not 
    apply.
        D. Important Social or Economic Development Analysis. Identify 
    the social or economic development and the benefits to the area in 
    which the waters are located that will be foregone if the lowering 
    of water quality is not allowed.
        E. Special Provision for Remedial Actions. Entities proposing 
    remedial actions pursuant to the CERCLA, as amended, corrective 
    actions pursuant to the Resource Conservation and Recovery Act, as 
    amended, or similar actions pursuant to other Federal or State 
    environmental statutes may submit information to the Director that 
    demonstrates that the action utilizes the most cost effective 
    pollution prevention and treatment techniques available, and 
    minimizes the necessary lowering of water quality, in lieu of the 
    information required by sections III.B through III.D of this 
    appendix.
    
    IV. Antidegradation Decision
    
        A. Once the Director determines that the information provided by 
    the entity proposing to increase loadings is administratively 
    complete, the Director shall use that information to determine 
    whether or not the lowering of water quality is necessary, and, if 
    it is necessary, whether or not the lowering of water quality will 
    support important social and economic development in the area. If 
    the proposed lowering of water quality is either not necessary, or 
    will not support important social and economic development, the 
    Director shall deny the request to lower water quality. If the 
    lowering of water quality is necessary, and will support important 
    social and economic development, the Director may allow all or part 
    of the proposed lowering to occur as necessary to accommodate the 
    important social and economic development. In no event may the 
    decision reached under this section allow water quality to be 
    lowered below the minimum level required to fully support existing 
    and designated uses. The decision of the Director shall be subject 
    to the public participation requirements of 40 CFR 25.
        B. If States designate the waters of Lake Superior as 
    Outstanding International Resource Waters pursuant to section II.E.2 
    of this appendix, any entity requesting to lower water quality in 
    the Lake Superior Basin as a result of the new or increased 
    discharge of any Lake Superior bioaccumulative substance of 
    immediate concern shall be required to install and utilize the best 
    technology in process and treatment as identified by the Director.
    
    Appendix F to Part 132--Great Lakes Water Quality Initiative 
    Implementation Procedures
    
    Procedure 1: Site-specific Modifications to Criteria and Values
    
        Great Lakes States and Tribes shall adopt provisions consistent 
    with (as protective as) this procedure.
        A. Requirements for Site-specific Modifications to Criteria and 
    Values. Criteria and values may be modified on a site-specific basis 
    to reflect local environmental conditions as restricted by the 
    following provisions. Any such modifications must be protective of 
    designated uses and aquatic life, wildlife or human health and be 
    submitted to EPA for approval. In addition, any site-specific 
    modifications that result in less stringent criteria must be based 
    on a sound scientific rationale and shall not be likely to 
    jeopardize the continued existence of endangered or threatened 
    species listed or proposed under section 4 of the Endangered Species 
    Act (ESA) or result in the destruction or adverse modification of 
    such species' critical habitat. More stringent modifications shall 
    be developed to protect endangered or threatened species listed or 
    proposed under section 4 of the ESA, where such modifications are 
    necessary to ensure that water quality is not likely to jeopardize 
    the continued existence of such species or result in the destruction 
    or adverse modification of such species' critical habitat. More 
    stringent modifications may also be developed to protect candidate 
    (C1) species being considered by the U.S. Fish and Wildlife Service 
    (FWS) for listing under section 4 of the ESA, where such 
    modifications are necessary to protect such species.
        1. Aquatic Life.
        a. Aquatic life criteria or values may be modified on a site-
    specific basis to provide an additional level of protection, 
    pursuant to authority reserved to the States and Tribes under Clean 
    Water Act (CWA) section 510.
        Guidance on developing site-specific criteria in these instances 
    is provided in Chapter 3 of the U.S. EPA Water Quality Standards 
    Handbook, Second Edition--Revised (1994).
        b. Less stringent site-specific modifications to chronic or 
    acute aquatic life criteria or values may be developed when:
        i. The local water quality characteristics such as Ph, hardness, 
    temperature, color, etc., alter the biological availability or 
    toxicity of a pollutant; or
        ii. The sensitivity of the aquatic organisms species that 
    ``occur at the site'' differs from the species actually tested in 
    developing the criteria. The phrase ``occur at the site'' includes 
    the species, genera, families, orders, classes, and phyla that: are 
    usually present at the site; are present at the site only seasonally 
    due to migration; are present intermittently because they 
    periodically return to or extend their ranges into the site; were 
    present at the site in the past, are not currently present at the 
    site due to degraded conditions, and are expected to return to the 
    site when conditions improve; are present in nearby bodies of water, 
    are not currently present at the site due to degraded conditions, 
    and are expected to be present at the site when conditions improve. 
    The taxa that ``occur at the site'' cannot be determined merely by 
    sampling downstream and/or upstream of the site at one point in 
    time. ``Occur at the site'' does not include taxa that were once 
    present at the site but cannot exist at the site now due to 
    permanent physical alteration of the habitat at the site resulting, 
    for example, from dams, etc.
        c. Less stringent modifications also may be developed to acute 
    and chronic aquatic life criteria or values to reflect local 
    physical and hydrological conditions.
        Guidance on developing site-specific criteria is provided in 
    Chapter 3 of the U.S. EPA Water Quality Standards Handbook, Second 
    Edition--Revised (1994). [[Page 15415]] 
        d. Any modifications to protect threatened or endangered aquatic 
    species required by procedure 1.A of this appendix may be 
    accomplished using either of the two following procedures:
        i. If the Species Mean Acute Value (SMAV) for a listed or 
    proposed species, or for a surrogate of such species, is lower than 
    the calculated Final Acute Value (FAV), such lower SMAV may be used 
    instead of the calculated FAV in developing site-specific modified 
    criteria; or,
        ii. The site-specific criteria may be calculated using the 
    recalculation procedure for site-specific modifications described in 
    Chapter 3 of the U.S. EPA Water Quality Standards Handbook, Second 
    Edition--Revised (1994).
        2. Wildlife.
        a. Wildlife water quality criteria may be modified on a site-
    specific basis to provide an additional level of protection, 
    pursuant to authority reserved to the States and Tribes under CWA 
    section 510.
        b. Less stringent site-specific modifications to wildlife water 
    quality criteria may be developed when a site-specific 
    bioaccumulation factor (BAF) is derived which is lower than the 
    system-wide BAF derived under appendix B of this part. The 
    modification must consider both the mobility of prey organisms and 
    wildlife populations in defining the site for which criteria are 
    developed. In addition, there must be a showing that:
        i. Any increased uptake of the toxicant by prey species 
    utilizing the site will not cause adverse effects in wildlife 
    populations; and
        ii. Wildlife populations utilizing the site or downstream waters 
    will continue to be fully protected.
        c. Any modification to protect endangered or threatened wildlife 
    species required by procedure 1.A of this appendix must consider 
    both the mobility of prey organisms and wildlife populations in 
    defining the site for which criteria are developed, and may be 
    accomplished by using the following recommended method.
        i. The methodology presented in appendix D to part 132 is used, 
    substituting appropriate species-specific toxicological, 
    epidemiological, or exposure information, including changes to the 
    BAF;
        ii. An interspecies uncertainty factor of 1 should be used where 
    epidemiological data are available for the species in question. If 
    necessary, species-specific exposure parameters can be derived as 
    presented in Appendix D of this part;
        iii. An intraspecies uncertainty factor (to account for 
    protection of individuals within a wildlife population) should be 
    applied in the denominator of the effect part of the wildlife 
    equation in appendix D of this part in a manner consistent with the 
    other uncertainty factors described in appendix D of this part; and
        iv. The resulting wildlife value for the species in question 
    should be compared to the two class-specific wildlife values which 
    were previously calculated, and the lowest of the three shall be 
    selected as the site-specific modification.
    
        Note: Further discussion on the use of this methodology may be 
    found in the Great Lakes Water Quality Initiative Technical Support 
    Document for Wildlife Criteria.
    
        3. BAFs.
        a. BAFs may be modified on a site-specific basis to larger 
    values, pursuant to the authority reserved to the States and Tribes 
    under CWA section 510, where reliable data show that local 
    bioaccumulation is greater than the system-wide value.
        b. BAFs may be modified on a site-specific basis to lower 
    values, where scientifically defensible, if:
        i. The fraction of the total chemical that is freely dissolved 
    in the ambient water is different than that used to derive the 
    system-wide BAFs (i.e., the concentrations of particulate organic 
    carbon and the dissolved organic carbon are different than those 
    used to derive the system-wide BAFs);
        ii. Input parameters of the Gobas model, such as the structure 
    of the aquatic food web and the disequilibrium constant, are 
    different at the site than those used to derive the system-wide 
    BAFs;
        iii. The percent lipid of aquatic organisms that are consumed 
    and occur at the site is different than that used to derive the 
    system-wide BAFs; or
        iv. Site-specific field-measured BAFs or biota-sediment 
    accumulation factor (BSAFs) are determined.
        If site-specific BAFs are derived, they shall be derived using 
    the methodology in appendix B of this part.
        c. Any more stringent modifications to protect threatened or 
    endangered species required by procedure 1.A of this appendix shall 
    be derived using procedures set forth in the methodology in appendix 
    B of this part.
        4. Human Health.
        a. Human health criteria or values may be modified on a site-
    specific basis to provide an additional level of protection, 
    pursuant to authority reserved to the States and Tribes under CWA 
    section 510. Human health criteria or values shall be modified on a 
    site-specific basis to provide additional protection appropriate for 
    highly exposed subpopulations.
        b. Less stringent site-specific modifications to human health 
    criteria or values may be developed when:
        i. local fish consumption rates are lower than the rate used in 
    deriving human health criteria or values under appendix C of this 
    part; and/or
        ii. a site-specific BAF is derived which is lower than that used 
    in deriving human health criteria or values under appendix C of this 
    part.
        B. Notification Requirements. When a State proposes a site-
    specific modification to a criterion or value as allowed in section 
    4.A above, the State should notify the other Great Lakes States of 
    such a proposal and, for less stringent criteria, supply appropriate 
    justification.
        C. References.
        U.S. EPA. 1984. Water Quality Standards Handbook--Revised. 
    Chapter 3 and Appendices. U.S. Environmental Protection Agency, 
    Office of Water Resource Center (RC-4100), 401 M Street, SW., 
    Washington, DC 20960.
    
    Procedure 2: Variances from Water Quality Standards for Point Sources
    
        The Great Lakes States or Tribes may adopt water quality 
    standards (WQS) variance procedures and may grant WQS variances for 
    point sources pursuant to such procedures. Variance procedures shall 
    be consistent with (as protective as) the provisions in this 
    procedure.
        A. Applicability. A State or Tribe may grant a variance to a WQS 
    which is the basis of a water quality-based effluent limitation 
    included in a National Pollutant Discharge Elimination System 
    (NPDES) permit. A WQS variance applies only to the permittee 
    requesting the variance and only to the pollutant or pollutants 
    specified in the variance. A variance does not affect, or require 
    the State or Tribe to modify, the corresponding water quality 
    standard for the waterbody as a whole.
        1. This provision shall not apply to new Great Lakes dischargers 
    or recommencing dischargers.
        2. A variance to a water quality standard shall not be granted 
    that would likely jeopardize the continued existence of any 
    endangered or threatened species listed under Section 4 of the 
    Endangered Species Act (ESA) or result in the destruction or adverse 
    modification of such species' critical habitat.
        3. A WQS variance shall not be granted if standards will be 
    attained by implementing effluent limits required under sections 
    301(b) and 306 of the Clean Water Act (CWA) and by the permittee 
    implementing cost-effective and reasonable best management practices 
    for nonpoint source control.
        B. Maximum Timeframe for Variances. A WQS variance shall not 
    exceed five years or the term of the NPDES permit, whichever is 
    less. A State or Tribe shall review, and modify as necessary, WQS 
    variances as part of each water quality standards review pursuant to 
    section 303(c) of the CWA.
        C. Conditions to Grant a Variance. A variance may be granted if:
        1. The permittee demonstrates to the State or Tribe that 
    attaining the WQS is not feasible because:
        a. Naturally occurring pollutant concentrations prevent the 
    attainment of the WQS;
        b. Natural, ephemeral, intermittent or low flow conditions or 
    water levels prevent the attainment of the WQS, unless these 
    conditions may be compensated for by the discharge of sufficient 
    volume of effluent to enable WQS to be met without violating State 
    or Tribal water conservation requirements;
        c. Human-caused conditions or sources of pollution prevent the 
    attainment of the WQS and cannot be remedied, or would cause more 
    environmental damage to correct than to leave in place;
        d. Dams, diversions or other types of hydrologic modifications 
    preclude the attainment of the WQS, and it is not feasible to 
    restore the waterbody to its original condition or to operate such 
    modification in a way that would result in the attainment of the 
    WQS;
        e. Physical conditions related to the natural features of the 
    waterbody, such as the lack of a proper substrate cover, flow, 
    depth, pools, riffles, and the like, unrelated to chemical water 
    quality, preclude attainment of WQS; or [[Page 15416]] 
        f. Controls more stringent than those required by sections 
    301(b) and 306 of the CWA would result in substantial and widespread 
    economic and social impact.
        2. In addition to the requirements of C.1, above, the permittee 
    shall also:
        a. Show that the variance requested conforms to the requirements 
    of the State's or Tribe's antidegradation procedures; and
        b. Characterize the extent of any increased risk to human health 
    and the environment associated with granting the variance compared 
    with compliance with WQS absent the variance, such that the State or 
    Tribe is able to conclude that any such increased risk is consistent 
    with the protection of the public health, safety and welfare.
        D. Submittal of Variance Application. The permittee shall submit 
    an application for a variance to the regulatory authority issuing 
    the permit. The application shall include:
        1. All relevant information demonstrating that attaining the WQS 
    is not feasible based on one or more of the conditions in section 
    C.1 of this procedure; and,
        2. All relevant information demonstrating compliance with the 
    conditions in section C.2 of this procedure.
        E. Public Notice of Preliminary Decision. Upon receipt of a 
    complete application for a variance, and upon making a preliminary 
    decision regarding the variance, the State or Tribe shall public 
    notice the request and preliminary decision for public comment 
    pursuant to the regulatory authority's Administrative Procedures Act 
    and shall notify the other Great Lakes States and Tribes of the 
    preliminary decision. This public notice requirement may be 
    satisfied by including the supporting information for the variance 
    and the preliminary decision in the public notice of a draft NPDES 
    permit.
        F. Final Decision on Variance Request. The State or Tribe shall 
    issue a final decision on the variance request within 90 days of the 
    expiration of the public comment period required in section E of 
    this procedure. If all or part of the variance is approved by the 
    State or Tribe, the decision shall include all permit conditions 
    needed to implement those parts of the variance so approved. Such 
    permit conditions shall, at a minimum, require:
        1. Compliance with an initial effluent limitation which, at the 
    time the variance is granted, represents the level currently 
    achievable by the permittee, and which is no less stringent than 
    that achieved under the previous permit;
        2. That reasonable progress be made toward attaining the water 
    quality standards for the waterbody as a whole through appropriate 
    conditions;
        3. When the duration of a variance is shorter than the duration 
    of a permit, compliance with an effluent limitation sufficient to 
    meet the underlying water quality standard, upon the expiration of 
    said variance; and
        4. A provision that allows the permitting authority to reopen 
    and modify the permit based on any State or Tribal triennial water 
    quality standards revisions to the variance.
        The State shall deny a variance request if the permittee fails 
    to make the demonstrations required under section C of this 
    procedure.
        G. Incorporating Variance into Permit. The State or Tribe shall 
    establish and incorporate into the permittee's NPDES permit all 
    conditions needed to implement the variance as determined in section 
    F of this procedure.
        H. Renewal of Variance. A variance may be renewed, subject to 
    the requirements of sections A through G of this procedure. As part 
    of any renewal application, the permittee shall again demonstrate 
    that attaining WQS is not feasible based on the requirements of 
    section C of this procedure. The permittee's application shall also 
    contain information concerning its compliance with the conditions 
    incorporated into its permit as part of the original variance 
    pursuant to sections F and G of this procedure. Renewal of a 
    variance may be denied if the permittee did not comply with the 
    conditions of the original variance.
        I. EPA Approval. All variances and supporting information shall 
    be submitted by the State or Tribe to the appropriate EPA regional 
    office and shall include:
        1. Relevant permittee applications pursuant to section D of this 
    procedure;
        2. Public comments and records of any public hearings pursuant 
    to section E of this procedure;
        3. The final decision pursuant to section F of this procedure; 
    and,
        4. NPDES permits issued pursuant to section G of this procedure.
        5. Items required by sections I.1 through I.3. of this procedure 
    shall be submitted by the State within 30 days of the date of the 
    final variance decision. The item required by section I.4 of this 
    procedure shall be submitted in accordance with the State or Tribe 
    Memorandum of Agreement with the Regional Administrator pursuant to 
    40 CFR 123.24.
        6. EPA shall review the State or Tribe submittal for compliance 
    with the CWA pursuant to 40 CFR 123.44, and 40 CFR 131.21.
        J. State WQS Revisions. All variances shall be appended to the 
    State or Tribe WQS rules.
    
    Procedure 3: Total Maximum Daily Loads, Wasteload Allocations for Point 
    Sources, Load Allocations for Nonpoint Sources, Wasteload Allocations 
    in the Absence of a TMDL, and Preliminary Wasteload Allocations for 
    Purposes of Determining the Need for Water Quality Based Effluent 
    Limits
    
        The Great Lakes States and Tribes shall adopt provisions 
    consistent with (as protective as) this procedure 3 for the purpose 
    of developing Total Maximum Daily Loads (TMDLs), Wasteload 
    Allocations (WLAs) in the Absence of TMDLs, and Preliminary 
    Wasteload Allocations for Purposes of Determining the Need for Water 
    Quality Based Effluent Limits (WQBELs), except as specifically 
    provided.
        A. Where a State or Tribe develops an assessment and remediation 
    plan that the State or Tribe certifies meets the requirements of 
    sections B through F of this procedure and public participation 
    requirements applicable to TMDLs, and that has been approved by EPA 
    as meeting those requirements under 40 CFR 130.6, the assessment and 
    remediation plan may be used in lieu of a TMDL for purposes of 
    appendix F to part 132. Assessment and remediation plans under this 
    procedure may include, but are not limited to, Lakewide Management 
    Plans, Remedial Action Plans, and State Water Quality Management 
    Plans. Also, any part of an assessment and remediation plan that 
    also satisfies one or more requirements under Clean Water Act (CWA) 
    section 303(d) or implementing regulations may be incorporated by 
    reference into a TMDL as appropriate. Assessment and remediation 
    plans under this section should be tailored to the level of detail 
    and magnitude for the watershed and pollutant being assessed.
        B. General Conditions of Application. Except as provided in 
    Sec. 132.4, the following are conditions applicable to establishing 
    TMDLs for all pollutants and pollutant parameters in the Great Lakes 
    System, with the exception of whole effluent toxicity, unless 
    otherwise provided in procedure 6 of appendix F. Where specified, 
    these conditions also apply to wasteload allocations (WLAs) 
    calculated in the absence of TMDLs and to preliminary WLAs for 
    purposes of determining the needs for WQBELs under procedure 5 of 
    appendix F.
        1. TMDLs Required. TMDLs shall, at a minimum, be established in 
    accordance with the listing and priority setting process established 
    in section 303(d) of the CWA and at 40 CFR 130.7. Where water 
    quality standards cannot be attained immediately, TMDLs must reflect 
    reasonable assurances that water quality standards will be attained 
    in a reasonable period of time. Some TMDLs may be based on attaining 
    water quality standards over a period of time, with specific 
    controls on individual sources being implemented in stages. 
    Determining the reasonable period of time in which water quality 
    standards will be met is a case-specific determination considering a 
    number of factors including, but not limited to: receiving water 
    characteristics; persistence, behavior and ubiquity of pollutants of 
    concern; type of remediation activities necessary; available 
    regulatory and non-regulatory controls; and individual State or 
    Tribal requirements for attainment of water quality standards.
        2. Attainment of Water Quality Standards. A TMDL must ensure 
    attainment of applicable water quality standards, including all 
    numeric and narrative criteria, Tier I criteria, and Tier II values 
    for each pollutant or pollutants for which a TMDL is established.
        3. TMDL Allocations.
        a. TMDLs shall include WLAs for point sources and load 
    allocations (LAs) for nonpoint sources, including natural 
    background, such that the sum of these allocations is not greater 
    than the loading capacity of the water for the pollutant(s) 
    addressed by the TMDL, minus the sum of a specified margin of safety 
    (MOS) and any capacity reserved for future growth.
        b. Nonpoint source LAs shall be based on:
        i. Existing pollutant loadings if changes in loadings are not 
    reasonably anticipated to occur;
        ii. Increases in pollutant loadings that are reasonably 
    anticipated to occur; [[Page 15417]] 
        iii. Anticipated decreases in pollutant loadings if such 
    decreased loadings are technically feasible and are reasonably 
    anticipated to occur within a reasonable time period as a result of 
    implementation of best management practices or other load reduction 
    measures. In determining whether anticipated decreases in pollutant 
    loadings are technically feasible and can reasonably be expected to 
    occur within a reasonable period of time, technical and 
    institutional factors shall be considered. These decisions are case-
    specific and should reflect the particular TMDL under consideration.
        c. WLAs. The portion of the loading capacity not assigned to 
    nonpoint sources including background, or to an MOS, or reserved for 
    future growth is allocated to point sources. Upon reissuance, NPDES 
    permits for these point sources must include effluent limitations 
    consistent with WLAs in EPA-approved or EPA-established TMDLs.
        d. Monitoring. For LAs established on the basis of subsection 
    b.iii above, monitoring data shall be collected and analyzed in 
    order to validate the TMDL's assumptions, to varify anticipated load 
    reductions, to evaluate the effectiveness of controls being used to 
    implement the TMDL, and to revise the WLAs and LAs as necessary to 
    ensure that water quality standards will be achieved within the 
    time-period established in the TMDL.
        4. WLA Values. If separate EPA-approved or EPA-established TMDLs 
    are prepared for different segments of the same watershed, and the 
    separate TMDLs each include WLAs for the same pollutant for one or 
    more of the same point sources, then WQBELs for that pollutant for 
    the point source(s) shall be consistent with the most stringent of 
    those WLAs in order to ensure attainment of all applicable water 
    quality standards.
        5. Margin of Safety (MOS). Each TMDL shall include a MOS 
    sufficient to account for technical uncertainties in establishing 
    the TMDL and shall describe the manner in which the MOS is 
    determined and incorporated into the TMDL. The MOS may be provided 
    by leaving a portion of the loading capacity unallocated or by using 
    conservative modeling assumptions to establish WLAs and LAs. If a 
    portion of the loading capacity is left unallocated to provide a 
    MOS, the amount left unallocated shall be described. If conservative 
    modeling assumptions are relied on to provide a MOS, the specific 
    assumptions providing the MOS shall be identified.
        6. More Stringent Requirements. States and Tribes may exercise 
    authority reserved to them under section 510 of the CWA to develop 
    more stringent TMDLs (including WLAs and LAs) than are required 
    herein, provided that all LAs in such TMDLs reflect actual nonpoint 
    source loads or those loads that can reasonably be expected to occur 
    within a reasonable time-period as a result of implementing nonpoint 
    source controls.
        7. Accumulation in Sediments. TMDLs shall reflect, where 
    appropriate and where sufficient data are available, contributions 
    to the water column from sediments inside and outside of any 
    applicable mixing zones. TMDLs shall be sufficiently stringent so as 
    to prevent accumulation of the pollutant of concern in sediments to 
    levels injurious to designated or existing uses, human health, 
    wildlife and aquatic life.
        8. Wet Weather Events. Notwithstanding the exception provided 
    for the establishment of controls on wet weather point sources in 
    Sec. 132.4(e)(1), TMDLs shall reflect, where appropriate and where 
    sufficient data are available, discharges resulting from wet weather 
    events. This procedure does not provide specific procedures for 
    considering discharges resulting from wet weather events. However, 
    some of the provisions of procedure 3 may be deemed appropriate for 
    considering wet weather events on a case-by-case basis.
        9. Background Concentration of Pollutants. The representative 
    background concentration of pollutants shall be established in 
    accordance with this subsection to develop TMDLs, WLAs calculated in 
    the absence of a TMDL, or preliminary WLAs for purposes of 
    determining the need for WQBELs under procedure 5 of appendix F. 
    Background loadings may be accounted for in a TMDL through an 
    allocation to a single ``background'' category or through individual 
    allocations to the various background sources.
        a. Definition of Background. ``Background'' represents all 
    loadings that: (1) flow from upstream waters into the specified 
    watershed, waterbody or waterbody segment for which a TMDL, WLA in 
    the absence of a TMDL or preliminary WLA for the purpose of 
    determining the need for a WQBEL is being developed; (2) enter the 
    specified watershed, waterbody or waterbody segment through 
    atmospheric deposition or sediment release or resuspension; or (3) 
    occur within the watershed, waterbody or waterbody segment as a 
    result of chemical reactions.
        b. Data considerations. When determining what available data are 
    acceptable for use in calculating background, the State or Tribe 
    should use best professional judgment, including consideration of 
    the sampling location and the reliability of the data through 
    comparison to reported analytical detection levels and 
    quantification levels. When data in more than one of the data sets 
    or categories described in section B.9.c.i through B.9.c.iii below 
    exist, best professional judgment should be used to select the one 
    data set that most accurately reflects or estimates background 
    concentrations. Pollutant degradation and transport information may 
    be considered when utilizing pollutant loading data.
        c. Calculation requirements. Except as provided below, the 
    representative background concentration for a pollutant in the 
    specified watershed, waterbody or waterbody segment shall be 
    established on a case-by-case basis as the geometric mean of:
        i. Acceptable available water column data; or
        ii. Water column concentrations estimated through use of 
    acceptable available caged or resident fish tissue data; or
        iii. Water column concentrations estimated through use of 
    acceptable available or projected pollutant loading data.
        d. Detection considerations.
        i. Commonly accepted statistical techniques shall be used to 
    evaluate data sets consisting of values both above and below the 
    detection level.
        ii. When all of the acceptable available data in a data set or 
    category, such as water column, caged or resident fish tissue or 
    pollutant loading data, are below the level of detection for a 
    pollutant, then all the data for that pollutant in that data set 
    shall be assumed to be zero.
        10. Effluent Flow. If WLAs are expressed as concentrations of 
    pollutants, the TMDL shall also indicate the point source effluent 
    flows assumed in the analyses. Mass loading limitations established 
    in NPDES permits must be consistent with both the WLA and assumed 
    effluent flows used in establishing the TMDL.
        11. Reserved Allocations. TMDLs may include reserved allocations 
    of loading capacity to accommodate future growth and additional 
    sources. Where such reserved allocations are not included in a TMDL, 
    any increased loadings of the pollutant for which the TMDL was 
    developed that are due to a new or expanded discharge shall not be 
    allowed unless the TMDL is revised in accordance with these 
    proceudres to include an allocation for the new or expanded 
    discharge.
        C. Mixing Zones for Bioaccumulative Chemicals of Concern (BCCs). 
    The following requirements shall be applied in establishing TMDLs, 
    WLAs in the absence of TMDLs, and preliminary WLAs for purposes of 
    determining the need for WQBELs under procedure 5 of appendix F, for 
    BCCs:
        1. Beginning on March 23, 1997, there shall be no mixing 
    available for new discharges of BCCs to the Great Lakes System. WLAs 
    established through TMDLs, WLAs in the absence of TMDLs, and 
    preliminary WLAs for purposes of determining the need for WQBELs for 
    new discharges of BCCs shall be set equal to the most stringent 
    applicable water quality criteria or values for the BCCs in 
    question.
        2. For purposes of section C of procedure 3 of appendix F, new 
    discharges are defined as: (1) discharges from new Great Lakes 
    dischargers; or (2) new or expanded discharges from an existing 
    Great Lakes discharger. All other discharges of BCCs are defined as 
    existing discharges.
        3. Up until March 23, 2007, mixing zones for BCCs may be allowed 
    for existing discharges to the Great Lakes System pursuant to the 
    procedures specified in sections D and E of this procedure.
        4. Except as provided in sections C.5 and C.6 of this procedure, 
    permits issued on or after March 23, 1997 shall not authorize mixing 
    zones for existing discharges of BCCs to the Great Lakes System 
    after March 23, 2007. After March 23, 2007, WLAs established through 
    TMDLs, WLAs established in the absence of TMDLs and preliminary WLAs 
    for purposes of determining the need for WQBELs under procedure 5 of 
    appendix F for existing dischrges of BCCs to the Great Lakes System 
    shall be set equal to the most stringent applicable water quality 
    criteria or values for the BCCs in question.
        5. Exception for Water Conservation. States and Tribes may grant 
    mixing zones for any existing discharge of BCCs to the Great Lakes 
    [[Page 15418]] System beyond the dates specified in sections C.3 and 
    C.4 of this procedure, where it can be demonstrated, on a case-by-
    case basis, that failure to grant a mixing zone would preclude water 
    conservation measures that would lead to overall load reductions in 
    BCCs, even though higher concentrations of BCCs occur in the 
    effluent. Such mixing zones must also be consistent with sections D 
    and E of this procedure.
        6. Exception for Technical and Economic Considerations. States 
    and Tribes may grant mixing zones beyond the dates specified in 
    sections C.3 and C.4 of this procedure for any existing discharges 
    of a BCC to the Great Lakes System upon the request of a discharger 
    subject to the limited circumstances specified in sections C.6.a 
    through C.6.d below. Such mixing zones shall also be consistent with 
    sections D and E of this procedure.
        a. The permitting authority must determine that:
        i. The discharger is in compliance with and will continue to 
    implement all applicable technology-based treatment and pretreatment 
    requirements of CWA sections 301, 302, 304, 306, 307, 401, and 402, 
    and is in compliance with its existing NPDES water quality-based 
    effluent limitations, including those based on a mixing zone; and
        ii. The discharger has reduced and will continue to reduce the 
    loading of the BCC for which a mixing zone is requested to the 
    maximum extent possible.
        b. In making the determination in section C.6.a above, the State 
    or Tribal authority should consider:
        i. The availability and feasibility, including cost 
    effectiveness, of additional controls or pollution prevention 
    measures for reducing and ultimately eliminating BCCs for that 
    discharger, including those used by similar dischargers;
        ii. Whether the discharger or affected communities will suffer 
    unreasonable economic effects if the mixing zone is eliminated;
        iii. The extent to which the discharger will implement an 
    ambient monitoring plan to ensure compliance with water quality 
    criteria at the edge of any authorized mixing zone or to ensure 
    consistency with any applicable TMDL or such other strategy 
    consistent with section A of this procedure; and,
        iv. Other information the State or Tribe deems appropriate.
        c. Any exceptions to the mixing zone elimination provision for 
    existing discharges of BCCs granted pursuant to this section shall:
        i. Not result in any less stringent limitations than those 
    existing March 23, 1997;
        ii. Not likely jeopardize the continued existence of any 
    endangered or threatened species listed under section 4 of the ESA 
    or result in the destruction or adverse modification of such 
    species' critical habitat;
        iii. Be limited to one permit term unless the permitting 
    authority makes a new determination in accordance with this section 
    for each successive permit application in which a mixing zone for 
    the BCC(s) is sought;
        iv. Reflect all information relevant to the size of the mixing 
    zone considered by the State or Tribe under subsection b above;
        v. Protect all designated and existing uses of the receiving 
    water;
        vi. Meet all applicable aquatic life, wildlife and human health 
    criteria and values at the edge of the mixing zone and, as 
    appropriate, within the mixing zone or be consistent with any 
    appropriate TMDL or such other strategy consistent with section A of 
    this procedure;
        vii. Ensure the discharger has developed and conducted a 
    pollutant minimization program for the BCC(s) if required to do so 
    under regulations adopted consistent with procedure 8 of appendix F; 
    and
        viii. Ensure that alternative means for reducing BCCs elsewhere 
    in the watershed are evaluated.
        d. For each draft NPDES permit that would allow a mixing zone 
    for one or more BCCs after March 23, 2007, the fact sheet or 
    statement of basis for the draft permit, required to be made 
    available through public notice under 40 CFR 124.6(e), shall:
        i. Specify the mixing provisions used in calculating the permit 
    limits; and
        ii. Identify each BCC for which a mixing zone is proposed.
        D. Deriving TMDLs, WLAs, and LAs for Point and Nonpoint Sources: 
    WLAs in the Absence of a TMDL; and Preliminary WLAs for Purposes of 
    Determining the Need for WQBELs for OWGL. This section addresses 
    conditions for deriving TMDLs for Open Waters of the Great Lakes 
    (OWGL), inland lakes and other waters of the Great Lakes System with 
    no appreciable flow relative to their volumes. State and Tribal 
    procedures to derive TMDLs under this section must be consistent 
    with (as protective as) the general conditions in section B of this 
    procedure, CWA section 303(d), existing regulations (40 CFR 130.7), 
    section C of this procedure, and sections D.1. through D.4 below. 
    State and Tribal procedures to derive WLAs calculated in the absence 
    of a TMDL and preliminary WLAs for purposes of determining the need 
    for WQBELs under procedure 5 of appendix F must be consistent with 
    sections B.9, C.1, C3 through C.6, and D. 1 through D.4 of this 
    procedure.
        1. Individual point source WLAs and preliminary WLAs for 
    purposes of determining the need for WQBELs under procedure 5 of 
    appendix F shall assume no greater dilution than one part effluent 
    to 10 parts receiving water for implementation of numeric and 
    narrative chronic criteria and values (including, but not limited to 
    human cancer criteria, human cancer values, human noncancer values, 
    human noncancer criteria, wildlife criteria, and chronic aquatic 
    life criteria and values) unless an alternative mixing zone is 
    demonstrated as appropriate in a mixing zone demonstration conducted 
    pursuant to section F of this procedure. In no case shall a mixing 
    zone be granted that exceeds the area where discharge-induced mixing 
    occurs.
        2. Appropriate mixing zone assumptions to be used in calculating 
    load allocations for nonpoint sources shall be determined, 
    consistent with applicable State or Tribal requirements, on a case-
    by-case basis.
        3. WLAs and preliminary WLAs based on acute aquatic life 
    criteria or values shall not exceed the Final Acute Value (FAV), 
    unless a mixing zone demonstration is conducted and approved 
    pursuant to section F of this procedure. If mixing zones from two or 
    more proximate sources interact or overlap, the combined effect must 
    be evaluated to ensure that applicable criteria and values will be 
    met in the area where acute mixing zones overlap.
        4. In no case shall a mixing zone be granted that would likely 
    jeopardize the continued existence of any endangered or threatened 
    species listed under section 4 of the ESA or result in the 
    destruction or adverse modification of such species' critical 
    habitat.
        E. Deriving TMDLs, WLAs, and LAs for Point and Nonpoint Sources; 
    WLAs in the Absence of a TMDL; and Preliminary WLAs for the Purposes 
    of Determining the Need for WQBELs for Great Lakes Systems 
    Tributaries and Connecting Channels. This section describes 
    conditions for deriving TMDLs for tributaries and connecting 
    channels of the Great Lakes System that exhibit appreciable flows 
    relative to their volumes. State and Tribal procedures to derive 
    TMDLs must be consistent with the general conditions listed in 
    section B of this procedure, section C of this procedure, existing 
    TMDL regulations (40 CFR 130.7) and specific conditions E.1 through 
    E.5. State and Tribal procedures to derive WLAs calculated in the 
    absence of a TMDL, and preliminary WLAs for purposes of determining 
    reasonable potential under procedure 5 of this appendix for 
    discharges to tributaries and connecting channels must be consistent 
    with sections B.9, C.1, C.3 through C.6, and E.1 through E.5 of this 
    procedure.
        1. Stream Design. These design flows must be used unless data 
    exist to demonstrate that an alternative stream design flow is 
    appropriate for stream-specific and pollutant-specific conditions. 
    For purposes of calculating a TMDL, WLAs in the absence of a TMDL, 
    or preliminary WLAs for the purposes of determining reasonable 
    potential under procedure 5 of this appendix, using a steady-state 
    model, the stream design flows shall be:
        a. The 7-day, 10-year stream design flow (7Q10), or the 4-day, 
    3-year biologically-based stream design flow for chronic aquatic 
    life criteria or values;
        b. The 1-day, 10-year stream design flow (1Q10), for acute 
    aquatic life criteria or values;
        c. The harmonic mean flow for human health criteria or values;
        d. The 90-day, 10-year flow (90Q10) for wildlife criteria.
        e. TMDLs, WLAs in the absence of TMDLs, and preliminary WLAs for 
    the purpose of determining the need for WQBELs calculated using 
    dynamic modelling do not need to incorporate the stream design flows 
    specified in sections E.1.a through E.1.d of this procedure.
        2. Loading Capacity. The loading capacity is the greatest amount 
    of loading that a water can receive without violating water quality 
    standards. The loading capacity is initially calculated at the 
    farthest downstream location in the watershed drainage basin. The 
    maximum allowable loading consistent with the attainment of each 
    applicable numeric [[Page 15419]] criterion or value for a given 
    pollutant is determined by multiplying the applicable criterion or 
    value by the flow at the farthest downstream location in the 
    tributary basin at the design flow condition described above. This 
    loading is then compared to the loadings at sites within the basin 
    to assure that applicable numeric criteria or values for a given 
    pollutant are not exceeded at all applicable sites. The lowest load 
    is then selected as the loading capacity.
        3. Polluant Degradation. TMDLs, WLAs in the absence of a TMDL 
    and preliminary WLAs for purposes of determining the need for WQBELs 
    under procedure 5 of appendix F shall be based on the assumption 
    that a pollutant does not degrade. However, the regulatory authority 
    may take into account degradation of the pollutant if each of the 
    following conditions are met.
        a. Scientifically valid field studies or other relevant 
    information demonstrate that degradation of the pollutant is 
    expected to occur under the full range of environmental conditions 
    expected to be encountered;
        b. Scientifically valid field studies or other relevant 
    information address other factors that affect the level of 
    pollutants in the water column including, but not limited to, 
    resuspension of sediments, chemical speciation, and biological and 
    chemical transformation.
        4. Acute Aquatic Life Criteria and Values. WLAs and LAs 
    established in a TMDL, WLAs in the absence of a TMDL, and 
    preliminary WLAs for the purpose of determining the need for WQBELs 
    based on acute aquatic life criteria or values shall not exceed the 
    FAV, unless a mixing zone demonstration is completed and approved 
    pursuant to section F of this procedure. If mixing zones from two or 
    more proximate sources interact or overlap, the combined effect must 
    be evaluated to ensure that applicable criteria and values will be 
    met in the area where any applicable acute mixing zones overlap. 
    This acute WLA review shall include, but not be limited to, 
    consideration of:
        a. The expected dilution under all effluent flow and 
    concentration conditions at stream design flow;
        b. Maintenance of a zone of passage for aquatic organisms; and
        c. Protection of critical aquatic habitat.
        In no case shall a permitting authority grant a mixing zone that 
    would likely jeopardize the continued existence of any endangered or 
    threatened species listed under section 4 of the ESA or result in 
    the destruction or adverse modification of such species' critical 
    habitat.
        5. Chronic Mixing Zones. WLAs and LAs established in a TMDL, 
    WLAs in the absence of a TMDL, and preliminary WLAs for the purposes 
    of determining the need for WQBELs for protection of aquatic life, 
    wildlife and human health from chronic effects shall be calculated 
    using a dilution fraction no greater than 25 percent of the stream 
    design flow unless a mixing zone demonstration pursuant to section F 
    of this procedure is conducted and approved. A demonstration for a 
    larger mixing zone may be provided, if approved and implemented in 
    accordance with section F of this procedure. In no case shall a 
    permitting authority grant a mixing zone that would likely 
    jeopardize the continued existence of any endangered or threatened 
    species listed under section 4 of the ESA or result in the 
    destruction or adverse modification of such species' critical 
    habitat.
        F. Mixing Zone Demonstration Requirements.
        1. For purposes of establishing a mixing zone other than as 
    specified in sections D and E above, a mixing zone demonstration 
    must:
        a. Describe the amount of dilution occurring at the boundaries 
    of the proposed mixing zone and the size, shape, and location of the 
    area of mixing, including the manner in which diffusion and 
    dispersion occur;
        b. For sources discharging to the open waters of the Great Lakes 
    (OWGLs), define the location at which discharge-induced mixing 
    ceases;
        c. Document the substrate character and geomorphology within the 
    mixing zone;
        d. Show that the mixing zone does not interfere with or block 
    passage of fish or aquatic life;
        e. Show that the mixing zone will be allowed only to the extent 
    that the level of the pollutant permitted in the waterbody would not 
    likely jeopardize the continued existence of any endangered or 
    threatened species listed under section 4 of the ESA or result in 
    the destruction or adverse modification of such species' critical 
    habitat;
        f. Show that the mixing zone does not extend to drinking water 
    intakes;
        g. Show that the mixing zone would not otherwise interfere with 
    the designated or existing uses of the receiving water or downstream 
    waters;
        h. Document background water quality concentrations;
        i. Show that the mixing zone does not promote undesirable 
    aquatic life or result in a dominance of nuisance species; and
        j. Provide that by allowing additional mixing/dilution:
        i. Substances will not settle to form objectionable deposits;
        ii. Floating debris, oil, scum, and other matter in 
    concentrations that form nuisances will not be produced; and
        iii. Objectionable color, odor, taste or turbidity will not be 
    produced.
        2. In addition, the mixing zone demonstration shall address the 
    following factors:
        a. Whether or not adjacent mixing zones overlap;
        b. Whether organisms would be attracted to the area of mixing as 
    a result of the effluent character; and
        c. Whether the habitat supports endemic or naturally occurring 
    species.
        3. The mixing zone demonstration must be submitted to EPA for 
    approval. Following approval of a mixing zone demonstration 
    consistent with sections F.1 and F.2, adjustment to the dilution 
    ratio specified in section D.1 of this procedure shall be limited to 
    the dilution available in the area where discharger-induced mixing 
    occurs.
        4. The mixing zone demonstration shall be based on the 
    assumption that a pollutant does not degrade within the proposed 
    mixing zone, unless:
        a. Scientifically valid field studies or other relevant 
    information demonstrate that degradation of the pollutant is 
    expected to occur under the full range of environmental conditions 
    expected to be encountered; and
        b. Scientifically valid field studies or other relevant 
    information address other factors that affect the level of 
    pollutants in the water column including, but not limited to, 
    resuspension of sediments, chemical speciation, and biological and 
    chemical transformation.
    
    Procedure 4: Additivity
    
        The Great Lakes States and Tribes shall adopt additivity 
    provisions consistent with (as protective as) this procedure.
        A. The Great Lakes States and Tribes shall adopt provisions to 
    protect human health from the potential adverse additive effects 
    from both the noncarcinogenic and carcinogenic components of 
    chemical mixtures in effluents. For the chlorinated dibenzo-p-
    dioxins (CDDs) and chlorinated dibenzofurans (CDFs) listed in Table 
    1, potential adverse additive effects in effluents shall be 
    accounted for in accordance with section B of this procedure.
        B. Toxicity Equivalency Factors (TEFs)/Bioaccumulation 
    Equivalency Factors (BEFs).
        1. The TEFs in Table 1 and BEFs in Table 2 shall be used when 
    calculating a 2,3,7,8-TCDD toxicity equivalence concentration in 
    effluent to be used when implementing both human health noncancer 
    and cancer criteria. The chemical concentration of each CDDs and 
    CDFs in effluent shall be converted to a 2,3,7,8-TCDD toxicity 
    equivalence concentration in effluent by (a) multiplying the 
    chemical concentration of each CDDs and CDFs in the effluent by the 
    appropriate TEF in Table 1 below, (b) multiplying each product from 
    step (a) by the BEF for each CDDs and CDFs in Table 2 below, and (c) 
    adding all final products from step (b). The equation for 
    calculating the 2,3,7,8-TCDD toxicity equivalence concentration in 
    effluent is:
    [GRAPHIC][TIFF OMITTED]TR23MR95.118
    
    
    where:
    
    (TEC)tcdd=2,3,7,8-TCDD toxicity equivalence concentration in 
    effluent
    (C)x=concentration of total chemical x in effluent
    (TEF)x=TCDD toxicity equivalency factor for x
    (BEF)x=TCDD bioaccumulation equivalency factor for x
    
        2. The 2,3,7,8-TCDD toxicity equivalence concentration in 
    effluent shall be used when developing waste load allocations under 
    procedure 3, preliminary waste load allocations for purposes of 
    determining reasonable potential under procedure 5, and for purposes 
    of establishing effluent quality limits under procedure 5.
    
            Table 1.--Toxicity Equivalency Factors for CDDs and CDFs        
    ------------------------------------------------------------------------
                              Congener                               TEF    
    ------------------------------------------------------------------------
    2,3,7,8-TCDD...............................................        1.0  
    1,2,3,7,8-PeCDD............................................        0.5  
    [[Page 15420]]                                                          
                                                                            
    1,2,3,4,7,8-HxCDD..........................................        0.1  
    1,2,3,6,7,8-HxCDD..........................................        0.1  
    1,2,3,7,8,9-HxCDD..........................................        0.1  
    1,2,3,4,6,7,8-HpCDD........................................        0.01 
    OCDD.......................................................        0.001
    2,3,7,8-TCDF...............................................        0.1  
    1,2,3,7,8-PeCDF............................................        0.05 
    2,3,4,7,8-PeCDF............................................        0.5  
    1,2,3,4,7,8-HxCDF..........................................        0.1  
    1,2,3,6,7,8-HxCDF..........................................        0.1  
    2,3,4,6,7,8-HxCDF..........................................        0.1  
    1,2,3,7,8,9-HxCDF..........................................        0.1  
    1,2,3,4,6,7,8-HpCDF........................................        0.01 
    1,2,3,4,7,8,9-HpCDF........................................        0.01 
    OCDF.......................................................        0.001
    ------------------------------------------------------------------------
    
    
         Table 2.--Bioaccumulation Equivalency Factors for CDDs and CDFs    
    ------------------------------------------------------------------------
                              Congener                               BEF    
    ------------------------------------------------------------------------
    2,3,7,8-TCDD...............................................        1.0  
    1,2,3,7,8-PeCDD............................................        0.9  
    1,2,3,4,7,8-HxCDD..........................................        0.3  
    1,2,3,6,7,8-HxCDD..........................................        0.1  
    1,2,3,7,8,9-HxCDD..........................................        0.1  
    1,2,3,4,6,7,8-HpCDD........................................        0.05 
    OCDD.......................................................        0.01 
    2,3,7,8-TCDF...............................................        0.8  
    1,2,3,7,8-PeCDF............................................        0.2  
    2,3,4,7,8-PeCDF............................................        1.6  
    1,2,3,4,7,8-HxCDF..........................................        0.08 
    1,2,3,6,7,8-HxCDF..........................................        0.2  
    2,3,4,6,7,8-HxCDF..........................................        0.7  
    1,2,3,7,8,9-HxCDF..........................................        0.6  
    1,2,3,4,6,7,8-HpCDF........................................        0.01 
    1,2,3,4,7,8,9-HpCDF........................................        0.4  
    OCDF.......................................................        0.02 
    ------------------------------------------------------------------------
    
    Procedure 5: Reasonable Potential To Exceed Water Quality Standards
    
        Great Lakes States and Tribes shall adopt provisions consistent 
    with (as protective as) this procedure. If a permitting authority 
    determines that a pollutant is or may be discharged into the Great 
    Lakes System at a level which will cause, have the reasonable 
    potential to cause, or contribute to an excursion above any Tier I 
    criterion or Tier II value, the permitting authority shall 
    incorporate a water quality-based effluent limitation (WQBEL) in an 
    NPDES permit for the discharge of that pollutant. When facility-
    specific effluent monitoring data are available, the permitting 
    authority shall make this determination by developing preliminary 
    effluent limitations (PEL) and comparing those effluent limitations 
    to the projected effluent quality (PEQ) of the discharge in 
    accordance with the following procedures. In all cases, the 
    permitting authority shall use any valid, relevant, representative 
    information that indicates a reasonable potential to exceed any Tier 
    I criterion or Tier II value.
        A. Developing Preliminary Effluent Limitations on the Discharge 
    of a Pollutant From a Point Source.
        1. The permitting authority shall develop preliminary wasteload 
    allocations (WLAs) for the discharge of the pollutant from the point 
    source to protect human health, wildlife, acute aquatic life, and 
    chronic aquatic life, based upon any existing Tier I criteria. Where 
    there is no Tier I criterion nor sufficient data to calculate a Tier 
    I criterion, the permitting authority shall calculate a Tier II 
    value for such pollutant for the protection of human health, and 
    aquatic life and the preliminary WLAs shall be based upon such 
    values. Where there is insufficient data to calculate a Tier II 
    value, the permitting authority shall apply the procedure set forth 
    in section C of this procedure to determine whether data must be 
    generated to calculate a Tier II value.
        2. The following provisions in procedure 3 of appendix F shall 
    be used as the basis for determining preliminary WLAs in accordance 
    with section 1 of this procedure: procedure 3.B.9, Background 
    Concentrations of Pollutants; procedure 3.C, Mixing Zones for 
    Bioaccumulative Chemicals of Concern (BCCs), procedures 3.C.1, and 
    3.C.3 through 3.C.6; procedure 3.D, Deriving TMDLs for Discharges to 
    Lakes (when the receiving water is an open water of the Great Lakes 
    (OWGL), an inland lake or other water of the Great Lakes System with 
    no appreciable flow relative to its volume); procedure 3.E, Deriving 
    TMDLs, WLAs and Preliminary WLAs, and load allocations (LAs) for 
    Discharges to Great Lakes System Tributaries (when the receiving 
    water is a tributary or connecting channel of the Great Lakes that 
    exhibits appreciable flow relative to its volume); and procedure 
    3.F, Mixing Zone Demonstration Requirements.
        3. The permitting authority shall develop PELs consistent with 
    the preliminary WLAs developed pursuant to sections A.1 and A.2 of 
    this procedure, and in accordance with existing State or Tribal 
    procedures for converting WLAs into WQBELs. At a minimum:
        a. The PELs based upon criteria and values for the protection of 
    human health and wildlife shall be expressed as monthly limitations;
        b. The PELs based upon criteria and values for the protection of 
    aquatic life from chronic effects shall be expressed as either 
    monthly limitations or weekly limitations; and
        c. The PELs based upon the criteria and values for the 
    protection of aquatic life from acute effects shall be expressed as 
    daily limitations.
        B. Determining Reasonable Potential Using Effluent Pollutant 
    Concentration Data.
        If representative, facility-specific effluent monitoring data 
    samples are available for a pollutant discharged from a point source 
    to the waters of the Great Lakes System, the permitting authority 
    shall apply the following procedures:
        1. The permitting authority shall specify the PEQ as the 95 
    percent confidence level of the 95th percentile based on a log-
    normal distribution of the effluent concentration; or the maximum 
    observed effluent concentration, whichever is greater. In 
    calculating the PEQ, the permitting authority shall identify the 
    number of effluent samples and the coefficient of variation of the 
    effluent data, obtain the appropriate multiplying factor from Table 
    1 of procedure 6 of appendix F, and multiply the maximum effluent 
    concentration by that factor. The coefficient of variation of the 
    effluent data shall be calculated as the ratio of the standard 
    deviation of the effluent data divided by the arithmetic average of 
    the effluent data, except that where there are fewer than ten 
    effluent concentration data points the coefficient of variation 
    shall be specified as 0.6. If the PEQ exceeds any of the PELs 
    developed in accordance with section A.3 of this procedure, the 
    permitting authority shall establish a WQBEL in a NPDES permit for 
    such pollutant.
        2. In lieu of following the procedures under section B.1 of this 
    procedure, the permitting authority may apply procedures consistent 
    with the following:
        a. The permitting authority shall specify the PEQ as the 95th 
    percentile of the distribution of the projected population of daily 
    values of the facility-specific effluent monitoring data projected 
    using a scientifically defensible statistical method that accounts 
    for and captures the long-term daily variability of the effluent 
    quality, accounts for limitations associated with sparse data sets 
    and, unless otherwise shown by the effluent data set, assumes a 
    lognormal distribution of the facility-specific effluent data. If 
    the PEQ exceeds the PEL based on the criteria and values for the 
    protection of aquatic life from acute effects developed in 
    accordance with section A.3 of this procedure, the permitting 
    authority shall establish a WQBEL in an NPDES permit for such 
    pollutant;
        b. The permitting authority shall calculate the PEQ as the 95th 
    percentile of the distribution of the projected population of 
    monthly averages of the facility-specific effluent monitoring data 
    using a scientifically defensible statistical method that accounts 
    for and captures the long-term variability of the monthly average 
    effluent quality, accounts for limitations associated with sparse 
    data sets and, unless otherwise shown by the effluent data set, 
    assumes a lognormal distribution of the facility-specific effluent 
    data. If the PEQ exceeds the PEL based on criteria and values for 
    the protection of aquatic life from chronic effects, human health or 
    wildlife developed in accordance with section A.3 of this procedure, 
    the permitting authority shall establish a WQBEL in an NPDES permit 
    for such pollutant; and
        c. The permitting authority shall calculate the PEQ as the 95th 
    percentile of the distribution of the projected population of weekly 
    averages of the facility-specific effluent monitoring data using a 
    scientifically defensible statistical method that accounts for and 
    captures the long-term variability of the weekly average effluent 
    quality, accounts for limitations associated with sparse data sets 
    and, unless otherwise shown by the effluent data set, assumes a 
    lognormal distribution of the facility-specific effluent data. If 
    the PEQ exceeds the PEL based on criteria and values to protect 
    aquatic life from chronic effects developed in accordance with 
    section A.3 of this procedure, the permitting 
    [[Page 15421]] authority shall establish a WQBEL in an NPDES permit 
    for such pollutant.
        C. Developing Necessary Data to Calculate Tier II Values Where 
    Such Data Does Not Currently Exist.
        1. Except as provided in sections C.2, C.4, or D of this 
    procedure, for each pollutant listed in Table 6 of part 132 that a 
    permittee reports as known or believed to be present in its 
    effluent, and for which pollutant data sufficient to calculate Tier 
    II values for non-cancer human health, acute aquatic life and 
    chronic aquatic life do not exist, the permitting authority shall 
    take the following actions:
        a. The permitting authority shall use all available, relevant 
    information, including Quantitative Structure Activity Relationship 
    information and other relevant toxicity information, to estimate 
    ambient screening values for such pollutant which will protect 
    humans from health effects other than cancer, and aquatic life from 
    acute and chronic effects.
        b. Using the procedures specified in sections A.1 and A.2 of 
    this procedure, the permitting authority shall develop preliminary 
    WLAs for the discharge of the pollutant from the point source to 
    protect human health, acute aquatic life, and chronic aquatic life, 
    based upon the estimated ambient screening values.
        c. The permitting authority shall develop PELs in accordance 
    with section A.3 of this procedure, which are consistent with the 
    preliminary WLAs developed in accordance with section C.1.b of this 
    procedure.
        d. The permitting authority shall compare the PEQ developed 
    according to the procedures set forth in section B of this procedure 
    to the PELs developed in accordance with section C.1.c of this 
    procedure. If the PEQ exceeds any of the PELs, the permitting 
    authority shall generate or require the permittee to generate the 
    data necessary to derive Tier II values for noncancer human health, 
    acute aquatic life and chronic aquatic life.
        e. The data generated in accordance with section C.1.d of this 
    procedure shall be used in calculating Tier II values as required 
    under section A.1 of this procedure. The calculated Tier II value 
    shall be used in calculating the preliminary WLA and PEL under 
    section A of this procedure, for purposes of determining whether a 
    WQBEL must be included in the permit. If the permitting authority 
    finds that the PEQ exceeds the calculated PEL, a WQBEL for the 
    pollutant or a permit limit on an indicator parameter consistent 
    with 40 CFR 122.44(d)(1)(vi)(C) must be included in the permit.
        2. With the exception of bioaccumulative chemicals of concern 
    (BCCs), a permitting authority is not required to apply the 
    procedures set forth in section C.1 of this procedure or include 
    WQBELs to protect aquatic life for any pollutant listed in Table 6 
    of part 132 discharged by an existing point source into the Great 
    Lakes System, if:
        a. There is insufficient data to calculate a Tier I criterion or 
    Tier II value for aquatic life for such pollutant;
        b. The permittee has demonstrated through a biological 
    assessment that there are no acute or chronic effects on aquatic 
    life in the receiving water; and
        c. The permittee has demonstrated in accordance with procedure 6 
    of this appendix that the whole effluent does not exhibit acute or 
    chronic toxicity.
        3. Nothing in sections C.1 or C.2 of this procedure shall 
    preclude or deny the right of a permitting authority to:
        a. Determine, in the absence of the data necessary to derive a 
    Tier II value, that the discharge of the pollutant will cause, have 
    the reasonable potential to cause, or contribute to an excursion 
    above a narrative criterion for water quality; and
        b. Incorporate a WQBEL for the pollutant into an NPDES permit.
        4. If the permitting authority develops a WQBEL consistent with 
    section C.3 of this procedure, and the permitting authority 
    demonstrates that the WQBEL developed under section C.3 of this 
    procedure is at least as stringent as a WQBEL that would have been 
    based upon the Tier II value or values for that pollutant, the 
    permitting authority shall not be obligated to generate or require 
    the permittee to generate the data necessary to derive a Tier II 
    value or values for that pollutant.
        D. Consideration of Intake Pollutants in Determining Reasonable 
    Potential.
        1. General.
        a. Any procedures adopted by a State or Tribe for considering 
    intake pollutants in water quality-based permitting shall be 
    consistent with this section and section E.
        b. The determinations under this section and section E shall be 
    made on a pollutant-by-pollutant, outfall-by-outfall, basis.
        c. This section and section E apply only in the absence of a 
    TMDL applicable to the discharge prepared by the State or Tribe and 
    approved by EPA, or prepared by EPA pursuant to 40 CFR 130.7(d), or 
    in the absence of an assessment and remediation plan submitted and 
    approved in accordance with procedure 3.A. of appendix F. This 
    section and section E do not alter the permitting authority's 
    obligation under 40 CFR 122.44(d)(vii)(B) to develop effluent 
    limitations consistent with the assumptions and requirements of any 
    available WLA for the discharge, which is part of a TMDL prepared by 
    the State or Tribe and approved by EPA pursuant to 40 CFR 130.7, or 
    prepared by EPA pursuant to 40 CFR 130.7(d).
        2. Definition of Same Body of Water.
        a. This definition applies to this section and section E of this 
    procedure.
        b. An intake pollutant is considered to be from the same body of 
    water as the discharge if the permitting authority finds that the 
    intake pollutant would have reached the vicinity of the outfall 
    point in the receiving water within a reasonable period had it not 
    been removed by the permittee. This finding may be deemed 
    established if:
        i. The background concentration of the pollutant in the 
    receiving water (excluding any amount of the pollutant in the 
    facility's discharge) is similar to that in the intake water;
        ii. There is a direct hydrological connection between the intake 
    and discharge points; and
        iii. Water quality characteristics (e.g., temperature, Ph, 
    hardness) are similar in the intake and receiving waters.
        c. The permitting authority may also consider other site-
    specific factors relevant to the transport and fate of the pollutant 
    to make the finding in a particular case that a pollutant would or 
    would not have reached the vicinity of the outfall point in the 
    receiving water within a reasonable period had it not been removed 
    by the permittee.
        d. An intake pollutant from groundwater may be considered to be 
    from the same body of water if the permitting authority determines 
    that the pollutant would have reached the vicinity of the outfall 
    point in the receiving water within a reasonable period had it not 
    been removed by the permittee, except that such a pollutant is not 
    from the same body of water if the groundwater contains the 
    pollutant partially or entirely due to human activity, such as 
    industrial, commercial, or municipal operations, disposed actions, 
    or treatment processes.
        e. An intake pollutant is the amount of a pollutant that is 
    present in waters of the United States (including groundwater as 
    provided in section D.2.d of this procedure) at the time it is 
    withdrawn from such waters by the discharger or other facility 
    (e.g., public water supply) supplying the discharger with intake 
    water.
        3. Reasonable Potential Determination.
        a. The permitting authority may use the procedure described in 
    this section of procedure 5 in lieu of procedures 5.A through C 
    provided the conditions specified below are met.
        b. The permitting authority may determine that there is no 
    reasonable potential for the discharge of an identified intake 
    pollutant or pollutant parameter to cause or contribute to an 
    excursion above a narrative or numeric water quality criterion 
    within an applicable water quality standard where a discharger 
    demonstrates to the satisfaction of the permitting authority (based 
    upon information provided in the permit application or other 
    information deemed necessary by the permitting authority) that:
        i. The facility withdraws 100 percent of the intake water 
    containing the pollutant from the same body of water into which the 
    discharge is made;
        ii. The facility does not contribute any additional mass of the 
    identified intake pollutant to its wastewater;
        iii. The facility does not alter the identified intake pollutant 
    chemically or physically in a manner that would cause adverse water 
    quality impacts to occur that would not occur if the pollutants were 
    left in-stream;
        iv. The facility does not increase the identified intake 
    pollutant concentration, as defined by the permitting authority, at 
    the edge of the mixing zone, or at the point of discharge if a 
    mixing zone is not allowed, as compared to the pollutant 
    concentration in the intake water, unless the increased 
    concentration does not cause or contribute to an excursion above an 
    applicable water quality standard; and
        v. The timing and location of the discharge would not cause 
    adverse water quality impacts to occur that would not occur if the 
    identified intake pollutant were left in-stream.
        c. Upon a finding under section D.3.b of this procedure that a 
    pollutant in the [[Page 15422]] discharge does not cause, have the 
    reasonable potential to cause, or contribute to an excursion above 
    an applicable water quality standard, the permitting authority is 
    not required to include a WQBEL for the identified intake pollutant 
    in the facility's permit, provided:
        i. The NPDES permit fact sheet or statement of basis includes a 
    specific determination that there is no reasonable potential for the 
    discharge of an identified intake pollutant to cause or contribute 
    to an excursion above an applicable narrative or numeric water 
    quality criterion and references appropriate supporting 
    documentation included in the administrative record;
        ii. The permit requires all influent, effluent, and ambient 
    monitoring necessary to demonstrate that the conditions in section 
    D.3.b of this procedure are maintained during the permit term; and
        iii. The permit contains a reopener clause authorizing 
    modification or revocation and reissuance of the permit if new 
    information indicates changes in the conditions in section D.3.b of 
    this procedure.
        d. Absent a finding under section D.3.b of this procedure that a 
    pollutant in the discharge does not cause, have the reasonable 
    potential to cause, or contribute to an excursion above an 
    applicable water quality standard, the permitting authority shall 
    use the procedures under sections 5.A through C of this procedure to 
    determine whether a discharge causes, has the reasonable potential 
    to cause, or contribute to an excursion above an applicable 
    narrative or numeric water quality criterion.
        E. Consideration of Intake Pollutants in Establishing WQBELs.
        1. General. This section applies only when the concentration of 
    the pollutant of concern upstream of the discharge (as determined 
    using the provisions in procedure 3.B.9 of appendix F) exceeds the 
    most stringent applicable water quality criterion for that 
    pollutant.
        2. The requirements of sections D.1-D.2 of this procedure shall 
    also apply to this section.
        3. Intake Pollutants from the Same Body of Water.
        a. In cases where a facility meets the conditions in sections 
    D.3.b.i and D.3.b.iii through D.3.b.v of this procedure, the 
    permitting authority may establish effluent limitations allowing the 
    facility to discharge a mass and concentration of the pollutant that 
    are no greater than the mass and concentration of the pollutant 
    identified in the facility's intake water (``no net addition 
    limitations''). The permit shall specify how compliance with mass 
    and concentration limitations shall be assessed. No permit may 
    authorize ``no net addition limitations'' which are effective after 
    March 23, 2007. After that date, WQBELs shall be established in 
    accordance with procedure 5.F.2 of appendix F.
        b. Where proper operation and maintenance of a facility's 
    treatment system results in removal of a pollutant, the permitting 
    authority may establish limitations that reflect the lower mass and/
    or concentration of the pollutant achieved by such treatment, taking 
    into account the feasibility of establishing such limits.
        c. For pollutants contained in intake water provided by a water 
    system, the concentration of the intake pollutant shall be 
    determined at the point where the raw water supply is removed from 
    the same body of water, except that it shall be the point where the 
    water enters the water supplier's distribution system where the 
    water treatment system removes any of the identified pollutants from 
    the raw water supply. Mass shall be determined by multiplying the 
    concentration of the pollutant determined in accordance with this 
    paragraph by the volume of the facility's intake flow received from 
    the water system.
        4. Intake Pollutants from a Different Body of Water. Where the 
    pollutant in a facility's discharge originates from a water of the 
    United States that is not the same body of water as the receiving 
    water (as determined in accordance with section D.2 of this 
    procedure), WQBELs shall be established based upon the most 
    stringent applicable water quality criterion for that pollutant.
        5. Multiple Sources of Intake Pollutants. Where a facility 
    discharges intake pollutants that originate in part from the same 
    body of water, and in part from a different body of water, the 
    permitting authority may apply the procedures of sections E.3 and 
    E.4 of this procedure to derive an effluent limitation reflecting 
    the flow-weighted average of each source of the pollutant, provided 
    that adequate monitoring to determine compliance can be established 
    and is included in the permit.
        F. Other Applicable Conditions.
        1. In addition to the above procedures, effluent limitations 
    shall be established to comply with all other applicable State, 
    Tribal and Federal laws and regulations, including technology-based 
    requirements and antidegradation policies.
        2. Once the permitting authority has determined in accordance 
    with this procedure that a WQBEL must be included in an NPDES 
    permit, the permitting authority shall:
        a. Rely upon the WLA established for the point source either as 
    part of any TMDL prepared under procedure 3 of this appendix and 
    approved by EPA pursuant to 40 CFR 130.7, or as part of an 
    assessment and remediation plan developed and approved in accordance 
    with procedure 3.A of this appendix, or, in the absence of such TMDL 
    or plan, calculate WLAs for the protection of acute and chronic 
    aquatic life, wildlife and human health consistent with the 
    provisions referenced in section A.1 of this procedure for 
    developing preliminary wasteload allocations, and
        b. Develop effluent limitations consistent with these WLAs in 
    accordance with existing State or Tribal procedures for converting 
    WLAs into WQBELs.
        3. When determining whether WQBELs are necessary, information 
    from chemical-specific, whole effluent toxicity and biological 
    assessments shall be considered independently.
        4. If the geometric mean of a pollutant in fish tissue samples 
    collected from a waterbody exceeds the tissue basis of a Tier I 
    criterion or Tier II value, after consideration of the variability 
    of the pollutant's bioconcentration and bioaccumulation in fish, 
    each facility that discharges detectable levels of such pollutant to 
    that water has the reasonable potential to cause or contribute to an 
    excursion above a Tier I criteria or a Tier II value and the 
    permitting authority shall establish a WQBEL for such pollutant in 
    the NPDES permit for such facility.
    
    Procedure 6: Whole Effluent Toxicity Requirements
    
        The Great Lakes States and Tribes shall adopt provisions 
    consistent with (as protective as) procedure 6 of appendix F of part 
    132.
        The following definitions apply to this part:
        Acute toxic unit (TUa). 100/LC50 where the LC50 
    is expressed as a percent effluent in the test medium of an acute 
    whole effluent toxicity (WET) test that is statistically or 
    graphically estimated to be lethal to 50 percent of the test 
    organisms.
        Chronic toxic unit (TUc). 100/NOEC or 100/IC25, where 
    the NOEC and IC25 are expressed as a percent effluent in the 
    test medium.
        Inhibition concentration 25 (IC25). the toxicant 
    concentration that would cause a 25 percent reduction in a non-
    quantal biological measurement for the test population. For example, 
    the IC25 is the concentration of toxicant that would cause a 25 
    percent reduction in mean young per female or in growth for the test 
    population.
        No observed effect concentration (NOEC). The highest 
    concentration of toxicant to which organisms are exposed in a full 
    life-cycle or partial life-cycle (short-term) test, that causes no 
    observable adverse effects on the test organisms (i.e., the highest 
    concentration of toxicant in which the values for the observed 
    responses are not statistically significantly different from the 
    controls).
        A. Whole Effluent Toxicity Requirements. The Great Lakes States 
    and Tribes shall adopt whole effluent toxicity provisions consistent 
    with the following:
        1. A numeric acute WET criterion of 0.3 acute toxic units 
    (TUa) measured pursuant to test methods in 40 CFR part 136, or 
    a numeric interpretation of a narrative criterion establishing that 
    0.3 TUa measured pursuant to test methods in 40 CFR part 136 is 
    necessary to protect aquatic life from acute effects of WET. At the 
    discretion of the permitting authority, the foregoing requirement 
    shall not apply in an acute mixing zone that is sized in accordance 
    with EPA-approved State and Tribal methods.
        2. A numeric chronic WET criterion of one chronic toxicity unit 
    (TUc) measured pursuant to test methods in 40 CFR part 136, or 
    a numeric interpretation of a narrative criterion establishing that 
    one TUc measured pursuant to test methods in 40 CFR part 136 is 
    necessary to protect aquatic life from the chronic effects of WET. 
    At the discretion of the permitting authority, the foregoing 
    requirements shall not apply within a chronic mixing zone consistent 
    with: (a) procedures 3.D.1 and 3.D.4, for discharges to the open of 
    the Great Lakes (OWGL), inland [[Page 15423]] lakes and other waters 
    of the Great Lakes System with no appreciable flow relative to their 
    volume, or (b) procedure 3.E.5 for discharges to tributaries and 
    connecting channels of the Great Lakes System.
        B. WET Test Methods. All WET tests performed to implement or 
    ascertain compliance with this procedure shall be performed in 
    accordance with methods established in 40 CFR part 136.
        C. Permit Conditions.
        1. Where a permitting authority determines pursuant to section D 
    of this procedure that the WET of an effluent is or may be 
    discharged at a level that will cause, have the reasonable potential 
    to cause, or contribute to an excursion above any numeric WET 
    criterion or narrative criterion within a State's or Tribe's water 
    quality standards, the permitting authority:
        a. Shall (except as provided in section C.1.e of this procedure) 
    establish a water quality-based effluent limitation (WQBEL) or 
    WQBELs for WET consistent with section C.1.b of this procedure;
        b. Shall calculate WQBELs pursuant to section C.1.a. of this 
    procedure to ensure attainment of the State's or Tribe's chronic WET 
    criteria under receiving water flow conditions described in 
    procedures 3.E.1.a (or where applicable, with procedure 3.E.1.e) for 
    Great Lakes System tributaries and connecting channels, and with 
    mixing zones no larger than allowed pursuant to section A.2. of this 
    procedure. Shall calculate WQBELs to ensure attainment of the 
    State's or Tribe's acute WET criteria under receiving water flow 
    conditions described in procedure 3.E.1.b (or where applicable, with 
    procedure 3.E.1.e) for Great Lakes System tributaries and connecting 
    channels, with an allowance for mixing zones no greater than 
    specified pursuant to section A.1 of this procedure.
        c. May specify in the NPDES permit the conditions under which a 
    permittee would be required to perform a toxicity reduction 
    evaluation.
        d. May allow with respect to any WQBEL established pursuant to 
    section C.1.a of this procedure an appropriate schedule of 
    compliance consistent with procedure 9 of appendix F; and
        e. May decide on a case-by-case basis that a WQBEL for WET is 
    not necessary if the State's or Tribe's water quality standards do 
    not contain a numeric criterion for WET, and the permitting 
    authority demonstrates in accordance with 40 CFR 122.44(d)(1)(v) 
    that chemical-specific effluent limits are sufficient to ensure 
    compliance with applicable criteria.
        2. Where a permitting authority lacks sufficient information to 
    determine pursuant to section D of this procedure whether the WET of 
    an effluent is or may be discharged at levels that will cause, have 
    the reasonable potential to cause, or contribute to an excursion 
    above any numeric WET criterion or narrative criterion within a 
    State's or Tribe's water quality standards, then the permitting 
    authority should consider including in the NPDES permit appropriate 
    conditions to require generation of additional data and to control 
    toxicity if found, such as:
        a. WET testing requirements to generate the data needed to 
    adequately characterize the toxicity of the effluent to aquatic 
    life;
        b. Language requiring a permit reopener clause to establish WET 
    limits if any toxicity testing data required pursuant to section 
    C.2.a of this procedure indicate that the WET of an effluent is or 
    may be discharged at levels that will cause, have the reasonable 
    potential to cause, or contribute to an excursion above any numeric 
    WET criterion or narrative criterion within a State's or Tribe's 
    water quality standards.
        3. Where sufficient data are available for a permitting 
    authority to determine pursuant to section D of this procedure that 
    the WET of an effluent neither is nor may be discharged at a level 
    that will cause, have the reasonable potential to cause, or 
    contribute to an excursion above any numeric WET criterion or 
    narrative criterion within a State's or Tribe's water quality 
    standards, the permitting authority may include conditions and 
    limitations described in section C.2 of this procedure at its 
    discretion.
        D. Reasonable Potential Determinations. The permitting authority 
    shall take into account the factors described in 40 CFR 
    122.44(d)(1)(ii) and, where representative facility-specific WET 
    effluent data are available, apply the following requirements in 
    determining whether the WET of an effluent is or may be discharged 
    at a level that will cause, have the reasonable potential to cause, 
    or contribute to an excursion above any numeric WET criterion or 
    narrative criterion within a State's or Tribe's water quality 
    standards.
        1. The permitting authority shall characterize the toxicity of 
    the discharge by:
        a. Either averaging or using the maximum of acute toxicity 
    values collected within the same day for each species to represent 
    one daily value. The maximum of all daily values for the most 
    sensitive species tested is used for reasonable potential 
    determinations;
        b. Either averaging or using the maximum of chronic toxicity 
    values collected within the same calendar month for each species to 
    represent one monthly value. The maximum of such values, for the 
    most sensitive species tested, is used for reasonable potential 
    determinations:
        c. Estimating the toxicity values for the missing endpoint using 
    a default acute-chronic ratio (ACR) of 10, when data exist for 
    either acute WET or chronic WET, but not for both endpoints.
        2. The WET of an effluent is or may be discharged at a level 
    that will cause, have the reasonable potential to cause, or 
    contribute to an excursion above any numeric acute WET criterion or 
    numeric interpretation of a narrative criterion within a State's or 
    Tribe's water quality standards, when effluent-specific information 
    demonstrates that:
    
    (TUa effluent) (B) (effluent flow/(Qad+effluent flow))>AC
    
    Where TUa effluent is the maximum measured acute toxicity of 
    100 percent effluent determined pursuant to section D.1.a. of this 
    procedure, B is the multiplying factor taken from Table F6-1 of this 
    procedure to convert the highest measured effluent toxicity value to 
    the estimated 95th percentile toxicity value for the discharge, 
    effluent flow is the same effluent flow used to calculate the 
    preliminary wasteload allocations (WLAs) for individual pollutants 
    to meet the acute criteria and values for those pollutants, AC is 
    the numeric acute WET criterion or numeric interpretation of a 
    narrative criterion established pursuant to section A.1 of this 
    procedure and expressed in TUa, and Qad is the amount of the 
    receiving water available for dilution calculated using: (i) the 
    specified design flow(s) for tributaries and connecting channels in 
    section C.1.b of this procedure, or where appropriate procedure 
    3.E.1.e of appendix F, and using EPA-approved State and Tribal 
    procedures for establishing acute mixing zones in tributaries and 
    connecting channels, or (ii) the EPA-approved State and Tribal 
    procedures for establishing acute mixing zones in OWGLs. Where there 
    are less than 10 individual WET tests, the multiplying factor taken 
    from Table F6-1 of this procedure shall be based on a coefficient of 
    variation (CV) or 0.6. Where there are 10 or more individual WET 
    tests, the multiplying factor taken from Table F6-1 shall be based 
    on a CV calculated as the standard deviation of the acute toxicity 
    values found in the WET tests divided by the arithmetic mean of 
    those toxicity values.
        3. The WET of an effluent is or may be discharged at a level 
    that will cause, have the reasonable potential to cause, or 
    contribute to an excursion above any numeric chronic WET criterion 
    or numeric interpretation of a narrative criterion within a State's 
    or Tribe's water quality standards, when effluent-specific 
    information demonstrates that:
    
    (TUc effluent) (B) (effluent flow/Qad+effluent flow))>CC
    
    Where TUc effluent is the maximum measured chronic toxicity 
    value of 100 percent effluent determined in accordance with section 
    D.1.b. of this procedure, B is the multiplying factor taken from 
    Table F6-1 of this procedure, effluent flow is the same effluent 
    flow used to calculate the preliminary WLAs for individual 
    pollutants to meet the chronic criteria and values for those 
    pollutants, CC is the numeric chronic WET criterion or numeric 
    interpretation of a narrative criterion established pursuant to 
    section A.2 of this procedure and expressed in TUc, and Qad is 
    the amount of the receiving water available for dilution calculated 
    using: (i) the design flow(s) for tributaries and connecting 
    channels specified in procedure 3.E.1.a of appendix F, and where 
    appropriate procedure 3.E.1.e of appendix F, and in accordance with 
    the provisions of procedure 3.E.5 for chronic mixing zones, or (ii) 
    procedures 3.D.1 and 3.D.4 for discharges to the OWGLs. Where there 
    are less than 10 individual WET tests, the multiplying factor taken 
    from Table F6-1 of this procedure shall be based on a CV of 0.6. 
    Where there are 10 more individual WET tests, the multiplying factor 
    taken from Table F6-1 of this procedure shall be based on a CV 
    calculated as the standard deviation of the WET tests divided by the 
    arithmetic mean of the WET tests.
    
                                                                            
    [[Page 15424]]                                                          
                                                  Table F6-1.--Reasonable Potential Multiplying Factors: 95% Confidence Level and 95% Probability Basis                                             
    ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                   Coefficient of variation                                                         
                      Number of Samples                  -------------------------------------------------------------------------------------------------------------------------------------------
                                                           0.1    0.2    0.3    0.4    0.5    0.6    0.7    0.8    0.9    1.0    1.1    1.2    1.3    1.4    1.5    1.6    1.7    1.8    1.9    2.0 
    ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
    1...................................................    1.4    1.9    2.6    3.6    4.7    6.2    8.0   10.1   12.6   15.5   18.7   22.3   26.4   30.8   35.6   40.7   46.2   52.1   58.4   64.9
    2...................................................    1.3    1.6    2.0    2.5    3.1    3.8    4.6    5.4    6.4    7.4    8.5    9.7   10.9   12.2   13.6   15.0   16.4   17.9   19.5   21.1
    3...................................................    1.2    1.5    1.8    2.1    2.5    3.0    3.5    4.0    4.6    5.2    5.8    6.5    7.2    7.9    8.6    9.3   10.0   10.8   11.5   12.3
    4...................................................    1.2    1.4    1.7    1.9    2.2    2.6    2.9    3.3    3.7    4.2    4.6    5.0    5.5    6.0    6.4    6.9    7.4    7.8    8.3    8.8
    5...................................................    1.2    1.4    1.6    1.8    2.1    2.3    2.6    2.9    3.2    3.6    3.9    4.2    4.5    4.9    5.2    5.6    5.9    6.2    6.6    6.9
    6...................................................    1.1    1.3    1.5    1.7    1.9    2.1    2.4    2.6    2.9    3.1    3.4    3.7    3.9    4.2    4.5    4.7    5.0    5.2    5.5    5.7
    7...................................................    1.1    1.3    1.4    1.6    1.8    2.0    2.2    2.4    2.6    2.8    3.1    3.3    3.5    3.7    3.9    4.1    4.3    4.5    4.7    4.9
    8...................................................    1.1    1.3    1.4    1.6    1.7    1.9    2.1    2.3    2.4    2.6    2.8    3.0    3.2    3.3    3.5    3.7    3.9    4.0    4.2    4.3
    9...................................................    1.1    1.2    1.4    1.5    1.7    1.8    2.0    2.1    2.3    2.4    2.6    2.8    2.9    3.1    3.2    3.4    3.5    3.6    3.8    3.9
    10..................................................    1.1    1.2    1.3    1.5    1.6    1.7    1.9    2.0    2.2    2.3    2.4    2.6    2.7    2.8    3.0    3.1    3.2    3.3    3.4    3.6
    11..................................................    1.1    1.2    1.3    1.4    1.6    1.7    1.8    1.9    2.1    2.2    2.3    2.4    2.5    2.7    2.8    2.9    3.0    3.1    3.2    3.3
    12..................................................    1.1    1.2    1.3    1.4    1.5    1.6    1.7    1.9    2.0    2.1    2.2    2.3    2.4    2.5    2.6    2.7    2.8    2.9    3.0    3.0
    13..................................................    1.1    1.2    1.3    1.4    1.5    1.6    1.7    1.8    1.9    2.0    2.1    2.2    2.3    2.4    2.5    2.5    2.6    2.7    2.8    2.9
    14..................................................    1.1    1.2    1.3    1.4    1.4    1.5    1.6    1.7    1.8    1.9    2.0    2.1    2.2    2.3    2.3    2.4    2.5    2.6    2.6    2.7
    15..................................................    1.1    1.2    1.2    1.3    1.4    1.5    1.6    1.7    1.8    1.8    1.9    2.0    2.1    2.2    2.2    2.3    2.4    2.4    2.5    2.5
    16..................................................    1.1    1.1    1.2    1.3    1.4    1.5    1.6    1.6    1.7    1.8    1.9    1.9    2.0    2.1    2.1    2.2    2.3    2.3    2.4    2.4
    17..................................................    1.1    1.1    1.2    1.3    1.4    1.4    1.5    1.6    1.7    1.7    1.8    1.9    1.9    2.0    2.0    2.1    2.2    2.2    2.3    2.3
    18..................................................    1.1    1.1    1.2    1.3    1.3    1.4    1.5    1.6    1.6    1.7    1.7    1.8    1.9    1.9    2.0    2.0    2.1    2.1    2.2    2.2
    19..................................................    1.1    1.1    1.2    1.3    1.3    1.4    1.5    1.5    1.6    1.6    1.7    1.8    1.8    1.9    1.9    2.0    2.0    2.0    2.1    2.1
    20..................................................    1.1    1.1    1.2    1.2    1.3    1.4    1.4    1.5    1.5    1.6    1.6    1.7    1.7    1.8    1.8    1.9    1.9    2.0    2.0    2.0
    30..................................................    1.0    1.1    1.1    1.1    1.2    1.2    1.2    1.3    1.3    1.3    1.3    1.4    1.4    1.4    1.4    1.5    1.5    1.5    1.5    1.5
    40..................................................    1.0    1.0    1.1    1.1    1.1    1.1    1.1    1.1    1.2    1.2    1.2    1.2    1.2    1.2    1.2    1.2    1.2    1.2    1.3    1.3
    50..................................................    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.1    1.1    1.1    1.1    1.1    1.1    1.1    1.1    1.1    1.1    1.1    1.1    1.1
    60..................................................    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0
    70..................................................    1.0    1.0    1.0    1.0    1.0    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9
    80..................................................    1.0    1.0    1.0    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.8    0.8    0.8    0.8    0.8    0.8
    90..................................................    1.0    1.0    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.8    0.8    0.8    0.8    0.8    0.8    0.8    0.8    0.8    0.8    0.8
    100.................................................    1.0    1.0    0.9    0.9    0.9    0.9    0.9    0.8    0.8    0.8    0.8    0.8    0.8    0.8    0.8    0.8    0.8    0.7    0.7    0.7
    ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
    
    Procedure 7: Loading Limits
    
        The Great Lakes States and Tribes shall adopt provisions 
    consistent with (as protective as) this procedure.
        Whenever a water quality-based effluent limitation (WQBEL) is 
    developed, the WQBEL shall be expressed as both a concentration 
    value and a corresponding mass loading rate.
        A. Both mass and concentration limits shall be based on the same 
    permit averaging periods such as daily, weekly, or monthly averages, 
    or in other appropriate permit averaging periods.
        B. The mass loading rates shall be calculated using effluent 
    flow rates that are consistent with those used in establishing the 
    WQBELs expressed in concentration.
    
    Procedure 8: Water Quality-based Effluent Limitations Below the 
    Quantification Level
    
        The Great Lakes States and Tribes shall adopt provisions 
    consistent with (as protective as) this procedure.
        When a water quality-based effluent limitation (WQBEL) for a 
    pollutant is calculated to be less than the quantification level:
        A. Permit Limits. The permitting authority shall designate as 
    the limit in the NPDES permit the WQBEL exactly as calculated.
        B. Analytical Method and Quantification Level.
        1. The permitting authority shall specify in the permit the most 
    sensitive, applicable, analytical method, specified in or approved 
    under 40 CFR part 136, or other appropriate method if one is not 
    available under 40 CFR part 136, to be used to monitor for the 
    presence and amount in an effluent of the pollutant for which the 
    WQBEL is established; and shall specify in accordance with section 
    B.2 of this procedure, the quantification level that can be achieved 
    by use of the specified analytical method.
        2. The quantification level shall be the minimum level (ML) 
    specified in or approved under 40 CFR part 136 for the method for 
    that pollutant. If no such ML exists, or if the method is not 
    specified or approved under 40 CFR part 136, the quantification 
    level shall be the lowest quantifiable level practicable. The 
    permitting authority may specify a higher quantification level if 
    the permittee demonstrates that a higher quantification level is 
    appropriate because of effluent-specific matrix interference.
        3. The permit shall state that, for the purpose of compliance 
    assessment, the analytical method specified in the permit shall be 
    used to monitor the amount of pollutant in an effluent down to the 
    quantification level, provided that the analyst has complied with 
    the specified quality assurance/quality control procedures in the 
    relevant method.
        4. The permitting authority shall use applicable State and 
    Tribal procedures to average and account for monitoring data. The 
    permitting authority may specify in the permit the value to be used 
    to interpret sample values below the quantification level.
        C. Special Conditions. The permit shall contain a reopener 
    clause authorizing modification or revocation and reissuance of the 
    permit if new information generated as a result of special 
    conditions included in the permit indicates that presence of the 
    pollutant in the discharge at levels above the WQBEL. Special 
    conditions that may be included in the permit include, but are not 
    limited to, fish tissue sampling, whole effluent toxicity (WET) 
    tests, limits and/or monitoring requirements on internal waste 
    streams, and monitoring for surrogate parameters. Data generated as 
    a result of special conditions can be used to reopen the permit to 
    establish more stringent effluent limits or conditions, if 
    necessary.
        D. Pollutant Minimization Program. The permitting authority 
    shall include a condition in the permit requiring the permittee to 
    develop and conduct a pollutant minimization program for each 
    pollutant with a WQBEL below the quantification level. The goal of 
    the pollutant minimization program shall be to reduce all potential 
    sources of the pollutant to maintain the effluent at or below the 
    WQBEL. In addition, States and Tribes may consider cost-
    effectiveness when establishing the requirements of a PMP. The 
    pollutant minimization program shall include, but is not limited to, 
    the following:
        1. An annual review and semi-annual monitoring of potential 
    sources of the pollutant, which may include fish tissue monitoring 
    and other bio-uptake sampling;
        2. Quarterly monitoring for the pollutant in the influent to the 
    wastewater treatment system;
        3. Submittal of a control strategy designed to proceed toward 
    the goal of maintaining all sources of the pollutant to the 
    wastewater collection system below the WQBEL;
        4. When the sources of the pollutant are discovered, appropriate 
    cost-effective control [[Page 15425]] measures shall be implemented, 
    consistent with the control strategy; and
        5. An annual status report that shall be sent to the permitting 
    authority including:
        a. All minimization program monitoring results for the previous 
    year;
        b. A list of potential sources of the pollutant; and
        c. A summary of all action taken to reduce or eliminate the 
    identified sources of the pollutant.
        6. Any information generated as a result of procedure 8.D can be 
    used to support a request for subsequent permit modifications, 
    including revisions to (e.g., more or less frequent monitoring), or 
    removal of the requirements of procedure 8.D, consistent with 40 CFR 
    122.44, 122.62 and 122.63.
    
    Procedure 9: Compliance Schedules
    
        The Great Lakes States and Tribes shall adopt provisions 
    consistent with (as protective as) procedure 9 of appendix F of part 
    132.
        A. Limitations for New Great Lakes Dischargers. When a permit 
    issued on or after March 23, 1997 to a new Great Lakes discharger 
    (defined in Part 132.2) contains a water quality-based effluent 
    limitation (WQBEL), the permittee shall comply with such a 
    limitation upon the commencement of the discharge.
        B. Limitations for Existing Great Lakes Dischargers.
        1. Any existing permit that is reissued or modified on or after 
    March 23, 1997 to contain a new or more restrictive WQBEL may allow 
    a reasonable period of time, up to five years from the date of 
    permit issuance or modification, for the permittee to comply with 
    that limit, provided that the Tier I criterion or whole effluent 
    toxicity (WET) criterion was adopted (or, in the case of a narrative 
    criterion, Tier II value, or Tier I criterion derived pursuant to 
    the methodology in appendix A of part 132, was newly derived) after 
    July 1, 1977.
        2. When the compliance schedule established under paragraph 1 
    goes beyond the term of the permit, an interim permit limit 
    effective upon the expiration date shall be included in the permit 
    and addressed in the permit's fact sheet or statement of basis. The 
    administrative record for the permit shall reflect the final limit 
    and its compliance date.
        3. If a permit establishes a schedule of compliance under 
    paragraph 1 which exceeds one year from the date of permit issuance 
    or modification, the schedule shall set forth interim requirements 
    and dates for their achievement. The time between such interim dates 
    may not exceed one year. If the time necessary for completion of any 
    interim requirement is more than one year and is not readily 
    divisible into stages for completion, the permit shall require, at a 
    minimum, specified dates for annual submission of progress reports 
    on the status of any interim requirements.
        C. Delayed Effectiveness of Tier II Limitations for Existing 
    Great Lakes Discharges.
        1. Whenever a limit (calculated in accordance with Procedure 3) 
    based upon a Tier II value is included in a reissued or modified 
    permit for an existing Great Lakes discharger, the permit may 
    provide a reasonable period of time, up to two years, in which to 
    provide additional studies necessary to develop a Tier I criterion 
    or to modify the Tier II value. In such cases, the permit shall 
    require compliance with the Tier II limitation within a reasonable 
    period of time, no later than five years after permit issuance or 
    modification, and contain a reopener clause.
        2. The reopener clause shall authorize permit modifications if 
    specified studies have been completed by the permittee or provided 
    by a third-party during the time allowed to conduct the specified 
    studies, and the permittee or a third-party demonstrates, through 
    such studies, that a revised limit is appropriate. Such a revised 
    limit shall be incorporated through a permit modification and a 
    reasonable time period, up to five years, shall be allowed for 
    compliance. If incorporated prior to the compliance date of the 
    original Tier II limitation, any such revised limit shall not be 
    considered less-stringent for purposes of the anti-backsliding 
    provisions of section 402(o) of the Clean Water Act.
        3. If the specified studies have been completed and do not 
    demonstrate that a revised limit is appropriate, the permitting 
    authority may provide a reasonable additional period of time, not to 
    exceed five years with which to achieve compliance with the original 
    effluent limitation.
        4. Where a permit is modified to include new or more stringent 
    limitations, on a date within five years of the permit expiration 
    date, such compliance schedules may extend beyond the term of a 
    permit consistent with section B.2 of this procedure.
        5. If future studies (other than those conducted under 
    paragraphs 1, 2, or 3 above) result in a Tier II value being changed 
    to a less stringent Tier II value or Tier I criterion, after the 
    effective date of a Tier II-based limit, the existing Tier II-based 
    limit may be revised to be less stringent if:
        (a) It complies with sections 402(o) (2) and (3) of the CWA; or,
        (b) In non-attainment waters, where the existing Tier II limit 
    was based on procedure 3, the cumulative effect of revised effluent 
    limitation based on procedure 3 of this appendix will assure 
    compliance with water quality standards; or,
        (c) In attained waters, the revised effluent limitation complies 
    with the State or Tribes' antidegradation policy and procedures.
    [FR Doc. 95-6671 Filed 3-22-95; 8:45 am]
    BILLING CODE 6560-50-P
    
    

Document Information

Effective Date:
4/24/1995
Published:
03/23/1995
Department:
Environmental Protection Agency
Entry Type:
Rule
Action:
Final rule.
Document Number:
95-6671
Dates:
April 24, 1995.
Pages:
15366-15425 (60 pages)
Docket Numbers:
FRL-5173-7
RINs:
2040-AC08
PDF File:
95-6671.pdf
CFR: (22)
40 CFR 122.26(b)(14)
40 CFR 132.4(c)
40 CFR 132.4(d)
40 CFR 9.1
40 CFR 122.44
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