96-13431. Soil Screening Guidance  

  • [Federal Register Volume 61, Number 106 (Friday, May 31, 1996)]
    [Notices]
    [Pages 27349-27351]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 96-13431]
    
    
    
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    ENVIRONMENTAL PROTECTION AGENCY
    [FRL-5510-3]
    
    
    Soil Screening Guidance
    
    AGENCY: Environmental Protection Agency.
    
    ACTION: Notice of availability of Soil Screening Guidance.
    
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    SUMMARY: The U.S. Environmental Protection Agency (EPA) has developed 
    the Soil Screening Guidance which is now available. This guidance 
    presents a framework for developing soil screening levels (SSLs), 
    focusing primarily on a simple methodology for developing site-specific 
    screening levels, but including generic levels and the opportunity to 
    do more detailed modeling. The guidance can serve as a tool to expedite 
    the evaluation of contaminated soils at sites addressed under the 
    Comprehensive Environmental Response, Compensation, and Liability Act 
    (CERCLA), commonly known as Superfund. The guidance is intended to be 
    used to screen out areas of sites, exposure pathways, or chemicals of 
    concern from further consideration, assuming certain conditions are 
    present, or to determine that further study is warranted at a site. It 
    is not a rule, does not have the force of a regulation, nor should it 
    be interpreted to represent cleanup standards for a site.
        The Soil Screening Guidance is presented in three documents: (1) a 
    Quick Reference Fact Sheet, which provides an overview of the 
    development and use of soil screening levels; (2) a User's Guide, which 
    provides details for implementing a simple methodology for calculating 
    site-specific SSLs; and (3) a Technical Background Document (TBD), 
    which presents generic SSLs and the technical foundation for the 
    methodology for establishing SSLs. These documents are available from 
    the National Technical Information Service at the address listed below. 
    Additional supporting information, including summaries of previous 
    outreach activities, is available for inspection in the Superfund 
    Docket at the address listed below.
        As part of the development of the Soil Screening Guidance, EPA 
    conducted extensive outreach and peer review. A major component of that 
    outreach was providing the document for public comment (59 FR 67706, 
    December 30, 1994). As a result of comments received during the public 
    comment period and the independent scientific peer review conducted 
    concurrently, several changes were made to the guidance. The highlights 
    of that process are presented below. In addition, EPA has developed a 
    more detailed Response to Comments on the public review draft and the 
    independent scientific peer review. This document is also available 
    from the National Technical Information Service (see below).
    
    DATES: The Soil Screening Guidance was signed by Assistant 
    Administrator Laws on May 17, 1996 and is now being published by 
    National Technical Information Service (NTIS).
    
    ADDRESSES: Copies of the draft Soil Screening Guidance may be ordered
    
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    through the NTIS at (703)487-4650 as follows:
    
    Soil Screening Guidance Quick Reference Fact Sheet, 9355.4-14FSA, PB96-
    963501, EPA/540/F-95/041
    Technical Background Document for Soil Screening Guidance, 9355.4-17A, 
    PB96-963502, EPA/540/R-95/128
    Soil Screening Guidance: User's Guide, 9355.4-23, PB96-963505, EPA/540/
    R-96/018
    Soil Screening Guidance: Response to Comments, 9355.4-22, PB96-963506, 
    EPA/540/R-96/019
    
        Members of the public are invited to inspect the docket developed 
    to support the Soil Screening Guidance at the Superfund Docket, U.S. 
    Environmental Protection Agency, 1235 Jefferson Davis Highway, 
    Arlington, Virginia. [Docket Number SSL]. The docket is available for 
    inspection between 9:00 a.m. and 4:00 p.m., Monday through Friday, 
    excluding Federal holidays. Appointments to review the docket can be 
    made by calling (703) 603-9232. The public may copy a maximum of 266 
    pages from the docket free of charge, however a charge of 15 cents will 
    be incurred for each additional page, plus a $25.00 administrative fee.
    
    FOR FURTHER INFORMATION CONTACT: The RCRA/Superfund Hotline at (800) 
    424-9346 (in the Washington, D.C. metropolitan area, (703) 412-9810). 
    The Telecommunications Device for the Deaf (TDD) Hotline number is 
    (800) 553-7672 (in the Washington, DC metropolitan area, (703) 412-
    3323). You may also contact David Cooper, Office of Emergency and 
    Remedial Response (5204G), U.S. Environmental Protection Agency, 401 M 
    Street, S.W., Washington, D.C. 20460, at (703) 603-8763.
    
    SUPPLEMENTARY INFORMATION:
    
    Introduction
    
        The U.S. Environmental Protection Agency (EPA) responds to releases 
    and threatened releases of hazardous substances under the authority of 
    the Comprehensive Environmental Response, Compensation, and Liability 
    Act of 1980 (CERCLA). Regulations governing such responses are found in 
    the National Oil and Hazardous Substances Pollution Contingency Plan or 
    NCP. The process for remedy selection in the NCP generally requires 
    that a remedial investigation be performed to identify the nature and 
    extent of contamination at National Priorities List (NPL) sites. From 
    sampling results, as well as site observations obtained in the field, 
    specific contaminants and exposure pathways of concern are identified 
    and used in a baseline risk assessment performed to determine whether 
    remedial action is warranted. (See source documents 1 and 2 listed at 
    the end of this document.)
        Today's Federal Register notice announces the availability of a new 
    tool which may reduce significantly the time it takes to complete soil 
    investigations and cleanup actions, as well as improve the consistency 
    of these actions across the nation. The guidance was written to enhance 
    the efficiency of remedial investigation/feasibility study (RI/FS) work 
    at Superfund National Priorities List (NPL) sites. This guidance on 
    developing soil screening levels is expected to assist site managers in 
    quickly identifying contaminated soil of potential concern and in 
    screening out from further consideration those soils that do not 
    warrant additional study.
        The Soil Screening Guidance presents three recommended methods for 
    developing risk-based, soil screening levels, but emphasizes a simple, 
    site-specific approach. The formulae and exposure assumptions used to 
    develop the screening levels have been taken from the Risk Assessment 
    Guidance for Superfund 1,2 and have been widely accepted in the 
    Superfund program for a number of years. These levels are then compared 
    to on-site soil contaminant levels. Areas of a site which fall below 
    the screening levels may be eliminated from further assessment. Areas 
    above the screening levels generally warrant further evaluation of the 
    potential risks that may be posed by site contaminants to determine the 
    need for response action. While the guidance is recommended for use as 
    a screening tool to determine if further study of specific portions of 
    a site is warranted, the levels should not be interpreted to represent 
    cleanup standards for a site.
    
    Background
    
        In 1993 EPA's Office of Emergency and Remedial Response (OERR) 
    developed a draft fact sheet entitled: ``Interim Soil Screening Level 
    Guidance.'' This guidance discussed the development and use of risk-
    based Soil Screening Levels (SSLs) for 30 common Superfund soil 
    contaminants. The document was issued on September 30, 1993, to provide 
    the basis for discussion of the SSL project with stakeholders and is 
    available for review as background information in the Superfund Docket. 
    The effort to develop such a guidance was requested under both the EPA 
    Administrator's June 19, 1991, ``30-Day Study,'' and the more recent 
    Superfund Administrative Improvements Initiatives announced by the 
    Deputy Administrator on June 23, 1993. This guidance was subsequently 
    revised and expanded to become the ``Soil Screening Guidance,'' dated 
    December 1994. This guidance was provided to the public for comment (59 
    FR 67706) and submitted to independent scientific peer review. As a 
    result of comments received in this process, we made several changes to 
    the document. Some of the most significant comments are highlighted 
    here. The Response to Comments provides a more in-depth discussion of 
    these changes and many other, less significant technical changes.
        (1) Guidance needs to be more user friendly. EPA has modified the 
    presentation of the guidance because many people commented that it was 
    not clear how to implement the guidance. The Soil Screening Guidance 
    has been reorganized into a ``user's guide'' to provide more useful 
    information on how to develop simple site-specific screening levels and 
    compare those to contaminant concentrations found at sites.
        (2) Generic SSLs will be misused. The generic SSLs are still part 
    of the framework, but they have been moved to the Technical Background 
    Document in an effort to prevent their misuse. They now appear in a 
    section which discusses the technical assumptions that go into the 
    development of those numbers.
        (3) Generic SSLs are too conservative. Another impetus for moving 
    the generic levels to the TBD is concern that the generic levels were 
    too conservative. One of the modeling inputs leading to this 
    conservatism is the assumption of an infinite source of contamination. 
    To address this concern, the new guidance provides an opportunity use 
    site-specific information to develop a conservative estimate of the 
    volume of contamination at the site.
        (4) Sampling strategy was based on an assumption that is not 
    appropriate for all sites. One of the peer reviewers commented that the 
    approach for sampling the site to determine the contaminant 
    concentrations was dependent on the assumption of a log-normal 
    distribution of contamination that may not actually occur at the site. 
    That approach has been replaced by a strategy that includes adequate 
    sampling of surface soil in the exposure area, compositing of some 
    samples to reduce laboratory costs, and comparison of the screening 
    level with the maximum of the composite samples from each exposure 
    area. The strategy balances the desire for a statistically based 
    sampling strategy with the need to control the number of samples and 
    the laboratory costs.
    
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        (5) Non-residential land uses need to be considered. EPA received 
    from many stakeholders that SSLs should be developed for other land 
    uses such as industrial or recreational. EPA agrees in principle that 
    other land uses need to be considered. However, as a first step in the 
    development of screening levels EPA chose to focus on residential use 
    because there is more agreement in the risk assessment community about 
    the types of relevant pathways and assumptions appropriate for modeling 
    residential exposures. Several of the Superfund reforms announced in 
    October 1995 address non-residential land uses and should provide 
    information which could be used to expand the soil screening guidance 
    to other land uses.
    
    Goals
    
        EPA's goal in developing this guidance is to provide a tool which 
    can be used to expedite the evaluation of contaminated soils at sites 
    addressed under CERCLA. The guidance is intended to be used to screen 
    out areas of sites, exposure pathways, or chemicals of concern from 
    further consideration or to determine that further study is warranted 
    at a site. It may be used where assumptions made in developing the tool 
    (e.g., residential land use, no ecological concerns) are consistent 
    with conditions found at specific sites.
        This guidance is not intended to be, and should not be construed as 
    a rule. Use of the guidance is not legally binding either on EPA staff 
    or on other parties; rather it is intended to be a tool available for 
    use under appropriate site-specific conditions. NPL sites do not all 
    meet the conditions necessary for its use, consequently, EPA does not 
    expect this tool to be useful at all NPL sites. EPA staff applying the 
    guidance have discretion to follow it or diverge from it as site-
    specific conditions may warrant, and each site-specific action will be 
    explained on its own record.
        Please contact individuals and offices listed in the sections of 
    this notice entitled ``Addresses'' and ``For Further Information 
    Contact'' to learn more about the Soil Screening Guidance.
    
    Source Documents
    
        1. U.S. EPA. 1989. Risk Assessment Guidance for Superfund: 
    Volume 1: Human Health Evaluation Manual, Part A, Interim Final. 
    EPA/540/1-89/002. Office of Emergency and Remedial Response, 
    Washington D.C. NTIS PB90-155581/CCE.
        2. U.S. EPA. 1991. Risk Assessment Guidance for Superfund, 
    Volume 1: Human Health Evaluation Manual (Part B, Development of 
    Risk-Based Preliminary Remediation Goals). Publication 9285.7-01B. 
    Office of Emergency and Remedial Response, Washington, D.C. NTIS 
    PB92-963333.
    
        Dated: May 17, 1996.
    Elliott P. Laws,
    Assistant Administrator.
    [FR Doc. 96-13431 Filed 5-30-96; 8:45 am]
    BILLING CODE 6560-50-P
    
    

Document Information

Published:
05/31/1996
Department:
Environmental Protection Agency
Entry Type:
Notice
Action:
Notice of availability of Soil Screening Guidance.
Document Number:
96-13431
Dates:
The Soil Screening Guidance was signed by Assistant Administrator Laws on May 17, 1996 and is now being published by National Technical Information Service (NTIS).
Pages:
27349-27351 (3 pages)
Docket Numbers:
FRL-5510-3
PDF File:
96-13431.pdf