[Federal Register Volume 60, Number 7 (Wednesday, January 11, 1995)]
[Rules and Regulations]
[Pages 2854-2871]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-546]
[[Page 2853]]
_______________________________________________________________________
Part IV
Environmental Protection Agency
_______________________________________________________________________
40 CFR Part 192
Groundwater Standards for Remedial Actions at Inactive Uranium
Processing Sites; Final Rule
Federal Register / Vol. 60, No. 7 / Wednesday, January 11, 1995 /
Rules and Regulations
[[Page 2854]]
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 192
[FRL-3510-1]
RIN 2060-AC03
Groundwater Standards for Remedial Actions at Inactive Uranium
Processing Sites
AGENCY: Environmental Protection Agency.
ACTION: Final rule.
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SUMMARY: The Environmental Protection Agency is issuing final
regulations to correct and prevent contamination of groundwater beneath
and in the vicinity of inactive uranium processing sites by uranium
tailings. EPA issued regulations (40 CFR part 192, subparts A, B, and
C) for cleanup and disposal of tailings from these sites on January 5,
1983. These new regulations replace existing provisions at 40 CFR
192.20(a)(2) and (3) that were remanded by the U.S. Court of Appeals
for the Tenth Circuit on September 3, 1985. They are promulgated
pursuant to Section 275 of the Atomic Energy Act, as amended by Section
206 of the Uranium Mill Tailings Radiation Control Act of 1978 (Public
Law 95-604).
The regulations apply to tailings at the 24 locations that qualify
for remedial action under Title I of Public Law 95-604. They provide
that tailings must be stabilized and controlled in a manner that
permanently eliminates or minimizes contamination of groundwater
beneath stabilized tailings, so as to protect human health and the
environment. They also provide for cleanup of contamination that
occurred before the tailings are stabilized.
EFFECTIVE DATE: February 10, 1995.
ADDRESSES: Background Documents. A report (``Groundwater Protection
Standards for Inactive Uranium Tailings Sites, Background Information
for Final Rule,'' EPA 520/1-88-023) has been prepared in support of
these regulations. Another report (``Groundwater Protection Standards
for Inactive Uranium Tailings Sites, Response to Comments,'' EPA 520/1-
88-055) contains the detailed responses of the Environmental Protection
Agency to comments on the standard by the reviewing public. Single
copies of these documents may be obtained from the Program Management
Office (6601J), Office of Radiation and Indoor Air, U.S. Environmental
Protection Agency, Washington, DC 20460; (202) 233-9354.
Docket. Docket Number R-87-01 contains the rulemaking record. The
docket is available for public inspection between 8 a.m.-4 p.m.,
weekdays, at EPA's Central Docket Section (LE-131), Room M-1500, 401 M
Street SW., Washington, DC 20460. A reasonable fee may be charged for
copying.
FOR FURTHER INFORMATION CONTACT: Allan C.B. Richardson, Criteria and
Standards Division (6602J), Office of Radiation and Indoor Air, U.S.
Environmental Protection Agency, Washington, DC 20460; telephone (202)
233-9213.
SUPPLEMENTARY INFORMATION:
I. Introduction
On November 8, 1978, Congress enacted the Uranium Mill Tailings
Radiation Control Act of 1978 (henceforth called ``UMTRCA''). In
UMTRCA, Congress found that uranium mill tailings ``* * * may pose a
potential and significant radiation health hazard to the public, and *
* * that every reasonable effort should be made to provide for
stabilization, disposal, and control in a safe and environmentally
sound manner of such tailings in order to prevent or minimize radon
diffusion into the environment and to prevent or minimize other
environmental hazards from such tailings.'' The Act directs the
Administrator of the Environmental Protection Agency (EPA) to set ``* *
* standards of general application for the protection of the public
health, safety, and the environment * * *'' to govern this process of
stabilization, disposal, and control.
UMTRCA directs the Department of Energy (DOE) to conduct such
remedial actions at the inactive uranium processing sites as will
insure compliance with the standards established by EPA. This remedial
action is to be selected and performed with the concurrence of the
Nuclear Regulatory Commission (NRC). Upon completion of the remedial
action program, the depository sites will remain in the custody of the
Federal government under an NRC license.
The standards apply to residual radioactive material at the 24
processing sites designated, as provided in the Act, by DOE. Residual
radioactive material is defined as any wastes which DOE determine to be
radioactive, either in the form of tailings resulting from the
processing of ores for the extraction of uranium and other valuable
constituents of the ores, or in other forms which relate to such
processing, such as sludges and captured contaminated water from these
sites. (Additional wastes that do not meet this definition may be
subject to regulation as hazardous waste under the Solid Waste Disposal
Act (SWDA) as amended by the Resource Conservation and Recovery Act of
1976 (RCRA).)
Standards are required for two types of remedial actions: disposal
and cleanup of residual radioactive material. Disposal is here used to
mean the operation that places tailings in a permanent condition which
will minimize risk of harmful effects to the health of people and harm
to the environment. Cleanup is the operation that eliminates, or
reduces to acceptable levels, the potential health and environmental
consequences of tailings or their constituents that have been dispersed
from tailings piles or disposal areas by natural forces or by human
activity, through removal of residual radioactive materials from land,
buildings, and groundwater.
On January 5, 1983, EPA promulgated final standards for the
disposal and cleanup of the inactive mill tailings sites under UMTRCA
(48 FR 590). These standards were challenged in the Tenth Circuit Court
of Appeals by several parties (Case Nos. 83-1014, 83-1041, 83-1206, and
83-1300). On September 3, 1985, the court dismissed all challenges
except one: it set aside the groundwater provisions of the regulations
at 40 CFR 192.20(a)(2) and (3) and remanded them to EPA ``* * * to
treat these toxic chemicals that pose a groundwater risk as it did in
the active mill site regulations.'' On September 24, 1987, EPA proposed
new standards to replace those remanded. A public hearing was held in
Durango, Colorado, on October 29, 1987. In response to requests from
several commenters at the public hearing and a later request by the
American Mining Congress, the public record for comments on the
proposed standard was not closed until January 29, 1988. With this
notice, EPA is establishing final standards to replace those set aside.
II. Summary of Background Information
Beginning in the 1940's, the U.S. Government purchased large
quantities of uranium for defense purposes. As a result, large piles of
tailings were created by the uranium milling industry. Tailings piles
pose a hazard to public health and the environment because they contain
radioactive and toxic constituents which emanate radon to the
atmosphere and may leach into groundwater. Tailings, which are a sand-
like material, have also been removed from tailings piles in the past
for use in construction and for soil
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conditioning. These uses are inappropriate, because the radioactive and
toxic constituents of tailings may elevate indoor radon levels, expose
people to gamma radiation, and leach into ground and surface waters.
Most of the mills are now inactive and many of the sites were
abandoned. These abandoned sites are being remediated under Title I of
UMTRCA. Congress designated 22 specific inactive sites in Title I of
UMTRCA, and the DOE subsequently added two more. Most remaining uranium
mill tailings sites are regulated by the NRC or States and will be
reclamated under Title II of UMTRCA. (DOE also owns one inactive site
at Monticello, Utah, that is not included under UMTRCA). The Title I
sites are located in the West, predominantly in arid areas, except for
a single site at Canonsburg, Pennsylvania. Before disposal operations
began, tailings piles at the inactive sites ranged in area from 5 to
150 acres and in height from only a few feet to as much as 230 feet.
The amount at each site ranges from residual contamination to 2.7
million tons of tailings. The 24 designated Title I sites combined
contain about 26 million tons of tailings covering a total of about
1000 acres.
Under the provisions of Title I of UMTRCA, the DOE is responsible
for the disposal of tailings at these sites, which will then be
licensed to DOE by NRC for long term surveillance and maintenance,
following NRC approval of the remediation. In addition, tailings that
were dispersed from the piles by natural forces or that have been
removed for use in or around buildings or on land are being retrieved
and replaced on the tailings piles prior to their disposal.
UMTRCA, as originally enacted, required that DOE complete all these
remedial actions within 7 years of the effective date of EPA's
standards, that is, by March 5, 1990. At the end of 1993 disposal
actions had been completed at ten sites: Canonsburg, Pennsylvania, one
of two sites in areas of high precipitation (Falls City, Texas is the
other); Shiprock, New Mexico; Salt Lake City, Utah; Lakeview, Oregon;
Green River, Utah; Spook and Riverton, Wyoming; Lowman, Idaho; Tuba
City, Arizona; and Durango, Colorado. Disposal actions were well
advanced at eight other sites: Rifle (two piles), Grand Junction, and
Gunnison, Colorado; Monument Valley, Arizona; Mexican Hat, Utah; Falls
City, Texas; and Ambrosia Lake, New Mexico. The remaining sites are in
the advanced stages of planning and should be under construction within
the next two years. In view of the rate of progress with remedial work,
Congress in 1988 extended the completion date for disposal and most
cleanup activities until September 30, 1994, and provided further ``* *
* that the authority of the Secretary to perform groundwater
restoration activities under this title is without limitation.''
(Uranium Mill Tailings Remedial Action Amendments Act of 1988, P.L.
100-616, November 5, 1988; 42 U.S.C. 7916). Section 1031 of the Energy
Policy Act of 1992 further extended the completion date for UMTRCA
surface stabilization (disposal) activities to September 30, 1996.
The most important hazardous constituent of uranium mill tailings
is radium, which is radioactive. Other potentially hazardous substances
in tailings piles include arsenic, molybdenum, selenium, uranium, and,
usually in lesser amounts, a variety of other toxic substances. The
concentrations of these materials in tailings vary from pile to pile,
ranging from 2 to more than 100 times local background soil
concentrations. A variety of organics is also known to have been used
at these sites.
Exposure to radioactive and toxic substances may cause cancer and
other diseases, as well as genetic damage and teratogenic effects.
Tailings pose a risk to health because: (1) Radium in tailings decays
into radon, a gaseous radioactive element which is easily transported
in air and the radioactive decay products of which may lodge in the
lungs; (2) individuals may be directly exposed to gamma radiation from
the radioactivity in tailings; and (3) radioactive and toxic substances
from tailings may leach into water and then be ingested with food or
water, or inhaled following aeration. It is the last of these hazards
that is primarily addressed here. (Although radon from radium in
groundwater is unlikely to pose a substantial hazard at these
locations, these standards also address that potential hazard.) The
other hazards are covered by existing provisions of 40 CFR part 192.
EPA's technical analysis was based on detailed reports for 14 of
the 24 inactive uranium mill tailings sites that had been developed by
late 1988 for the Department of Energy by its contractors. Preliminary
data for the balance of the sites were also examined. Those data showed
that the volumes of contaminated water in aquifers at the 24 sites
range from a few tens of millions of gallons to 4 billion gallons. In a
few instances mill effluent was apparently the sole source of this
groundwater. Each of the 14 sites examined in detail had at least some
groundwater contamination beneath and/or beyond the site. In some cases
the groundwater upgradient of the pile already exceeded EPA drinking
water standards for one or more contaminants due to mineralization
sources or due to anthropogenic sources other than the uranium milling
activities, thus making it unsuitable for use as drinking water without
treatment and, in some extreme cases, for most other purposes before it
was contaminated by effluent from the mill. Some contaminants from the
tailings piles are moving offsite quickly and others are moving slowly.
The time for natural flushing of the contaminated portions of these
aquifers was estimated to vary from a couple of years to many hundreds
of years. Active restoration was estimated to take from less than 5
years at most sites to approximately 50 years at one site.
DOE currently estimates that there is approximately 4.7 billion
gallons of contaminated water, but this estimate does not include all
sites. One site, Lowman, Idaho, shows no sign of contamination related
to the processing activities, while the site with the largest amount of
contamination, Monument Valley, Arizona, has an estimated 0.75 billion
gallons of contaminated water. The DOE estimate does not include those
sites where current assessments indicate that supplemental standards
should be applied, because contamination at these sites has been hard
to quantify.
Contaminants that have been identified in the groundwater
downgradient from a majority of the sites include uranium, sulfate,
iron, manganese, nitrate, chloride, molybdenum, selenium, and total
dissolved solids. Radium, arsenic, fluoride, sulfide, chromium,
cadmium, vanadium, lead, and copper have also been found in the
groundwater at one or more sites.
UMTRCA requires that the standards established under Title I
provide protection that is consistent, to the maximum extent
practicable, with the requirements of RCRA. In this regard, regulations
established by EPA for hazardous waste disposal sites under RCRA
provide for the specification of a groundwater protection standard for
each waste management area in the facility permit (see 40 CFR part 264,
subpart F). The groundwater protection standard includes a list of
specific hazardous constituents relevant to each waste management area,
a concentration limit for each hazardous constituent, the point of
compliance, and the compliance period. The subpart F regulations
specify that the concentration limits may be set at
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general numerical limits (maximum concentration limits (MCLs)) for some
hazardous constituents or at their background level in groundwater
unless alternate concentration limits (ACLs) are requested and
approved. ACLs may be requested based upon data which would support a
determination that, if the ACL is satisfied, the constituent would not
present a current or potential threat to human health and the
environment. This standard incorporates many of these provisions into
the regulations for the Title I sites.
III. Changes and Clarifications in Response to Comments
These final standards modify and clarify some of the provisions of
the proposed standards as a result of information and views submitted
during the comment period and at the public hearing. EPA received many
comments on the proposed standards. Twenty-three letters were received
and eight individuals testified at the public hearing. Comments were
submitted from private citizens, public interest groups, members of the
scientific community, and representatives of industry and of State and
Federal agencies. EPA has carefully reviewed and considered these
comments in preparing its detailed Response to Comments and the final
Background Information Document and in developing the final standards.
EPA's responses to major comments are summarized below.
Uranium Concentration Limit
Several commenters pointed out that the Agency used inappropriate
dose conversion values (nonstochastic) for uranium and radium (instead
of the more appropriate stochastic values) in developing the proposed
concentration limit for uranium. These comments were correct. We have
reevaluated the risks associated with ingestion of uranium, using
current risk factors for radiocarcinogenicity of uranium, and have also
considered the chemical toxicity of uranium. We have concluded that the
level proposed, 30 pCi/liter, provides an adequate margin of safety
against both carcinogenic and toxic effects of uranium, and that the
level should be expressed in terms of the concentration of
radioactivity, because it is related to the principal health risk, and
can accommodate different levels of radioactive disequilibrium between
uranium-234 and uranium-238.
EPA's Office of Groundwater and Drinking Water has also examined
these factors, and, on July 18, 1991, proposed the MCL for uranium in
drinking water be set at a chemical concentration comparable to the
limit on radioactivity promulgated in this regulation. Should the MCL
for drinking water, as finally promulgated, provide a level of health
protection different from that provided by the limit in this
regulation, EPA will reconsider the limit at that time. On the basis of
the above considerations, the limit for uranium has been established at
30 pCi/liter for this regulation.
Molybdenum Concentration Limit
Several reviewers objected to the proposed inclusion of a limit on
molybdenum. They pointed out that EPA has not established a drinking
water standard for this element. While this is true, the drinking water
regulations also make provision for health advisories in the case of
contaminants that are problems only in special situations. Molybdenum
in the vicinity of uranium mill tailings is such a special case.
Uranium mill tailings often contain high concentrations of molybdenum
that can leach into groundwater in concentrations that may cause toxic
effects in humans and cattle. This rule therefore continues to contain
a limit on the concentration of molybdenum in groundwater. The value
chosen remains the same as that proposed, as discussed in Section IV
below.
Other Groundwater Limits
These groundwater limits incorporate MCLs issued under the Safe
Drinking Water Act (SDWA) (42 USC 300f, et seq.) and in effect for
sites regulated under RCRA from the time these limits were proposed on
September 24, 1987, to the present. However, on January 30, 1991, EPA
issued new MCLs for some of the inorganic constituents included in the
present limits, and proposed new drinking water standards for
radioactive constituents were published on July 18, 1991 (56 FR 3526
and 33050). Following publication of final drinking water standards for
radioactive constituents, EPA will consider whether the benefits and
costs implied by differences between these limits and the new drinking
water standards warrant proposing to incorporate the new values into
both the Title I and the Title II limits for groundwater.
Application of These Regulations to Vicinity Properties
Several commenters questioned the wisdom of applying these
regulations to vicinity properties. (Vicinity properties are real
properties or improvements in the vicinity of a tailings pile that are
determined by DOE, in consultation with the NRC, to be contaminated
with residual radioactive materials.) They indicated that if the
portion of the proposed rule requiring detailed assessment and
monitoring were applied to all vicinity properties, it would greatly
expand the cost of the program without providing additional benefits.
Since only a few vicinity properties contain sufficient tailings to
constitute a significant threat of groundwater contamination, we have
concluded that detailed assessment and monitoring, followed by
identification of listed constituents and groundwater standards, is not
required at all vicinity properties. It is necessary only at those
vicinity properties with a significant potential for groundwater
contamination, as determined by the DOE (with the concurrence of NRC)
using factors such as those in EPA's RCRA Facility Assessment Guidance
document. It should be noted that this modification applies to the
requirement for detailed assessment and monitoring only; the standards
for cleanup of groundwater contamination are not changed. In addition,
we note that the minimal quantities of residual radioactive materials
left behind at vicinity properties after compliance with subpart B do
not constitute disposal sites under subpart A.
Application of State Regulations to These Sites
Some commenters expressed the view that these regulations should
require consistency with State laws and regulations. EPA's regulations
for licensed mill tailings sites under Title II of this Act do not
contain such a provision. (Although NRC Agreement States may, under the
Atomic Energy Act, adopt standards which ``* * * are equivalent to the
extent practicable or more stringent * * *,'' they have not done so
under UMTRCA.) We have decided that decisions regarding consistency
with State laws and regulations should be made by DOE in consultation
with the States, as provided by Section 103 of the Act. In making these
decisions in cases where an approved Wellhead Protection Area, under
the Safe Drinking Water Act, is associated with the site, however, DOE
must comply with the provisions of that program, unless an exemption is
granted by the President of the United States. In addition,
contamination on the site that is not covered by UMTRCA (because it is
not related to the processing operation) may be covered by Federal or
State RCRA programs.
Application of Institutional Controls During an Extended Remedial
Period
Several comments were received concerning the effectiveness,
reliability,
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and enforceability of institutional controls to be applied during a
remedial period that has been extended to take advantage of natural
flushing. EPA recognizes that some institutional controls, such as
advisories or signs, although desirable as secondary measures, are not
appropriate as primary measures for preventing human exposure to
contaminated water. For this reason, the regulations permit
institutional controls to be used in place of remediation only when DOE
is able to ensure their effectiveness will be maintained during their
use. The standards require that institutional controls ``* * *
effectively protect public health and the environment and satisfy
beneficial uses of groundwater * * *'' during their period of
application. In this regard, we note that tribal, state, and local
governments can also play a key role in assuring the effectiveness of
institutional controls. In some cases this may be effected through
changes in tribal, state, or local laws to ensure the enforceability of
institutional controls by the administrative or judicial branches of
government entities. One State indicated that some institutional
controls, such as deed restrictions, should not be viewed as
restrictions since they do not empower any agency to prohibit access to
contaminated water. However, judicial enforcement of deed restrictions
can be as effective as administrative enforcement of other
institutional controls by a government agency. Therefore, deed
restrictions are an acceptable institutional control if they are
enforceable by a court with jurisdiction over the site at which they
are used, and if the implementing agency will take appropriate steps to
assure their effective application.
Some commenters expressed the view that, if institutional controls
are used, this use must be restricted to the 7-year period for
remediation authorized in Section 112(a) of UMTRCA. EPA believes that
it is not possible to achieve cleanup of groundwater at all of the
sites within 7 years, no matter what reclamation scheme is employed. It
is therefore necessary to consider time frames other than that
originally contemplated in UMTRCA for completion of remedial actions.
Congress, in granting an extension of the authorization in Section
112(a) of UMTRCA for disposal and cleanup actions from March 5, 1990 to
September 30, 1994, provided further ``* * * that the authority of the
Secretary to perform groundwater restoration activities under this
title is without limitation.'' (Uranium Mill Tailings Remedial Action
Amendments Act of 1988 (42 U.S.C. 7916)). In addition, under Section
104(f)(2) of the Act (42 U.S.C. 7919(f)(2)), the NRC may require
maintenance of corrective and institutional measures that are already
in place at the time authorization under Section 112(a) expires,
without time limitation.
The provisions for use of natural flushing when appropriate
institutional controls are in place are consistent with existing
regulations under Title II, although they are not explicit in those
regulations. In cases where groundwater contamination is detected, the
Title II regulations specify when corrective actions must begin, but do
not specify a time when corrective actions must be completed. These
provisions under Title I provide additional guidance on the length of
time over which institutional control may reasonably be relied upon,
and further guidance on the kinds of institutional provisions that
would be appropriate at any uranium tailings site. In addition, use of
institutional controls is not limited to extended remedial periods.
Interim institutional controls may also be used to protect public
health or the environment, when DOE finds them necessary and
appropriate, prior to commencing active remedial action, during active
remedial action, or during implementation of other compliance
strategies.
Other comments addressed a variety of matters, including the
monitoring of institutional controls, the relationship between long-
term maintenance responsibilities and the 100-year limit on use of
institutional controls, types of institutional controls, longer or
shorter extended remedial periods, and the legality of institutional
controls under UMTRCA. These matters are addressed in the Response to
Comments, published separately as a background document.
Point of Compliance
Several commenters objected to the definition of the point of
compliance in the disposal standards (subpart A), and suggested that it
be defined at some finite distance from the edge of the remediated
tailings instead of at the downgradient edge of the pile, as in
regulations established under RCRA. They indicated that the remediated
tailings may seep a minor amount of contamination, which may cause the
standards to be exceeded at the proposed point of compliance, under
conditions where there would be no detriment to human health or the
environment at small distances away. This difficulty can be solved, as
proposed, by moving the point of compliance or, alternatively, by
granting an ACL if it can be shown that such levels of contamination
will not impair human health or damage the environment. We have
concluded the latter is more in keeping with the regulations
established under RCRA. The standards provide that DOE may request an
ACL under such circumstances and NRC may approve such a request if
contamination of groundwater will not endanger human health or degrade
the environment. It is our view that this requirement would usually be
satisfied at any site where the minor seepage noted above is not
projected to extend beyond a few hundred meters from the waste
management area and will not extend outside the site boundary. This
could occur under a variety of circumstances where important roles are
played by attenuation, dilution, or by vapor transport in unsaturated
zones.
Under the cleanup standard (subpart B), the DOE is required to
characterize the extent of contamination from the site and clean it up
wherever it exceeds the standards. This characterization and
confirmation of cleanup will be carried out through the monitoring
program established under Sec. 192.12(c)(3). Although the DOE is not
required to clean up preexisting contamination that is located beneath
a remediated tailings pile, they are required to consider this
contamination when developing their plan(s) for remedial action and
will have to clean up any contamination that will migrate from beneath
the pile and exceed the concentration limits established in accordance
with Sec. 192.02(c)(3).
Alternate Concentration Limits
Several reviewers commented that EPA should not, for a variety of
reasons, delegate the responsibility for approving ACLs to the NRC.
Others stated that the standards were so strict that ACLs would be
needed at every site. EPA considered a number of approaches to the
provision for granting ACLs. These included deleting the ACL provision,
establishing (by regulation) generic criteria for ACLs to be
implemented by NRC, providing for some form of EPA review or oversight
of ACL implementation, and (as in the proposed regulation) providing
for no EPA role in setting ACLs at individual sites.
EPA has decided not to delete the ACL provision because it is
clearly needed, if for no other reason than to deal with the
possibilities of unavoidable minor projected seepage over the extremely
long-term design life (1000 years) of the disposal required, in most
cases, by these standards, and of
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cleanup situations involving pollutants for which no MCLs exist.
Establishment of a complete set of regulations specifying generic
criteria for granting ACLs presents difficulties for rulemaking, since
ACL determinations often involve complex judgments that are not
amenable to being reduced to simple regulatory requirements. In this
regard we note that such regulations do not yet exist in final form for
sites directly regulated under RCRA. However, the Agency has issued
interim final Alternate Concentration Limit Guidance (OSWER Directive
9481.00; EPA/SW-87-017), and has proposed several relevant rules, e.g.,
under 40 CFR parts 264, 265, 270, and 271, for Corrective Action for
Solid Waste Management Units at Hazardous Waste Management Facilities
(55 FR 30798; July 27, 1990). In addition, the NRC proposed a draft
Technical Position on Alternate Concentration Limits for Uranium Mills
at Title II sites on March 21, 1994 (59 FR 13345). EPA has reviewed the
NRC draft Technical position, and we find that it is consistent, in
general, with EPA's own guidance and proposed rules. The NRC draft
position does not, however, specify an upper limit on risks to humans
from carcinogens. We have reconsidered the issue of EPA review or
oversight of ACLs at Title I sites in light of this review, and
concluded that, in the interests of assuring that public health is
adequately protected while at the same time minimizing the regulatory
burden on DOE, the best course of action is to specify that upper limit
in this regulation and assign the responsibility for making
determinations for ACLs at individual sites to NRC. Accordingly, in
this rule, in the implementing guidance contained in subpart C,
Sec. 192.20(a)(2), we now specify that the criterion for known or
suspected carcinogens contained in the above-referenced RCRA documents
should be applied in granting ACLs. That criterion specifies that ACLs
should be established at levels which represent an excess lifetime
risk, at a point of exposure, no greater than 10-4 to 10-6 to
an average individual.
EPA is required by UMTRCA (Section 206) to be consistent, to the
maximum extent practicable, with RCRA. For this reason, relevant
portions of the RCRA regulations have been incorporated. For example,
these regulations provide for the use of ACLs when it can be shown that
the criteria specified in Sec. 192.02(c)(3)(ii) are satisfied. It
remains the view of the Agency that, as at the Title II sites, an ACL
is appropriate if the NRC has determined that these criteria are
satisfied when the otherwise applicable standard will be met within the
site boundary (or at a distance of 500 meters, if this is closer). It
is clear that ACLs will usually be appropriate to accommodate the
controlled minor seepage anticipated from properly designed tailings
disposal within such distances, when public use is not possible.
Cost
Greater consideration of cost and cost-benefit analysis was
requested by several commenters. In 1983, Congress amended UMTRCA to
provide that when establishing standards the Administrator should
consider, among other factors, the economic costs of compliance. We
have considered these costs in two ways. First, we compared them to the
benefit, expressed in terms of the value of the product--processed
uranium ore--which has led to contamination of groundwater at these
sites. We estimate the present value of the processed uranium ore from
these sites as approximately 3.9 billion dollars (1989 dollars). The
estimated cost of compliance is approximately 5.5% of this value, and
we judge this to be a not unreasonable incremental cost for the
remediation of contamination from the operations which produced this
uranium. As a second way of considering the economic costs of
compliance, we examined the cost of alternative ways to supply the
resources for future use represented by these groundwaters. As noted
earlier, water is a scarce resource in the Western States where this
cleanup would occur. When other resources have been exhausted, the only
remaining alternative to cleaning up groundwater in the vicinity of
these sites is to replace this water by transporting water from the
nearest alternative source. Our analysis of the costs of doing this
indicates that it is significantly more costly to supply water from
alternative sources than it would be to clean up the groundwater at
these sites. We have concluded, therefore, that this final rule
involves a reasonable relationship between the overall costs and
benefits of compliance.
The RCRA subpart F regulations do not include cost as a
consideration for the degree of cleanup of groundwater, and these
regulations also do not provide for site-specific standards based on
site-specific costs. Nonetheless, it is clearly desirable and
appropriate to apply the most cost-effective remedies available to meet
these standards at each site, and we anticipate that DOE will make such
choices in choosing the remedies it applies to satisfy these standards.
Further, once the basic criteria for establishing ACLs set forth in
Sec. 192.02(c)(3)(ii)(B) have been satisfied, if a higher level of
protection is reasonably achievable, this should be carried out.
However, we do not believe it is appropriate to apply detailed cost/
benefit balancing judgments to justify lesser levels of protection for
ground water. The benefits of cleaning up groundwater are often not
quantifiable and may not become known for many years; therefore, site-
specific cost-benefit analyses are difficult to apply in such
situations. Moreover, Congress provided no authority that protection of
ground water at each site should be limited by cost/benefit
considerations, even after reconsidering the question in the 1984
amendments.
Some reviewers raised the issue of additional costs arising from
use of these standards in other applications, such as CERCLA cleanups.
We recognize that there may be costs associated with using these
standards as precedents for other waste cleanup projects. However, the
reasonableness of incurring such costs should be assessed when it is
possible to do so with complete information, that is, at the time of
application of these standards as precedents for situations other than
the one for which they were developed.
Natural Restoration
The use of natural restoration of an aquifer was discussed by
several reviewers. Some felt that it was a viable and desirable
alternative, because it is easy and inexpensive to apply, for
groundwaters that are not expected to be used for drinking or other
purposes during the cleanup period. Others felt that it should be
prohibited because it required a reliance on institutional controls and
would circumvent active cleanup of groundwater. EPA believes that the
use of natural restoration can be a viable alternative in situations
where water use and ecological considerations are not affected, and
cleanup will occur within a reasonable time. We have concluded that
institutional controls, when enforced by government entities, or that
otherwise have a high degree of permanence, can be relied on for
periods of time up to 100 years, and that adequate safeguards are
provided through NRC oversight of the implementation of these standards
to prevent this alternative from being used to circumvent active
cleanup of water that will be used by nearby populations.
Commenters suggested that natural restoration was not adequate to
restore water quality at these sites. DOE has indicated that they
expect that natural restoration may be all that is necessary at up to
eight sites and could be used
[[Page 2859]]
in conjunction with active remedial measures at several other sites.
Natural restoration is most valuable when the contaminated aquifer
discharges into a surface water body that will not be adversely
affected by the contamination.
Pile and Liner Design
The design of the remediated pile and the use of a liner was of
concern to several commenters, and recommendations were given for
suitable designs. These commenters feared that water would continually
infiltrate the remediated piles and contaminate groundwater.
These EPA standards would not be satisfied by designs which allow
contamination that would adversely affect human health or the
environment. Further, current engineering designs for covers
incorporate a number of features that control infiltration to extremely
low levels. These may include an erosion barrier (with vegetation,
where feasible) to transpire moisture and reduce infiltration; rock
filters and drains to drain and laterally disperse any episodic
infiltration; very low permeability infiltration barriers to intercept
residual infiltration; and finally, the thick radon barrier, which
further inhibits infiltration. The combined effect of these features is
to reduce the overall hydrological transmission of covers to levels on
the order of one part in a billion, with a resulting high probability
that there will be no saturated zone of leachate in or below the
tailings. EPA expects DOE to use such state-of-the-art designs wherever
it is appropriate to do so because of the proximity of groundwater.
Under the provisions of UMTRCA, the detailed design of the pile and
its cover is the responsibility of DOE, and confirmation of the
viability of the design to satisfy EPA's standards is the
responsibility of NRC. EPA's responsibility is to promulgate the
standards to which the disposal must conform. It would be inconsistent
with the division of responsibilities set forth in UMTRCA to specify
actual designs for the piles in these regulations. In this connection,
the requirement to provide a liner when tailings are moved to a new
location in a wet state is properly seen as a generic management
requirement. Any liner for this purpose would only serve a useful
purpose for the relatively short time over which the moisture content
of the pile adjusts to its long-term equilibrium value, after which the
cover design would determine the groundwater protection capability of
the disposal.
Restricted List of Constituents
Commenters were overwhelmingly opposed to a restricted list of
radioactive or toxic constituents and recommended that the entire list
of constituents be relied upon. It is the Agency's experience that,
under RCRA, no changes in this list have been requested based on the
criteria provided in Sec. 264.93(b). These criteria allow for hazardous
constituents to be excluded based on a determination that the
constituent does not pose a substantial present or potential hazard to
human health or the environment. Therefore, that portion of the RCRA
standards which specify conditions for the exclusion of constituents
from the RCRA list of hazardous constituents has been excluded as
unnecessary.
However, a short list of compounds has been developed by EPA for
use in monitoring groundwater under RCRA. This rule incorporates that
list of constituents (Appendix IX of part 264) in place of the complete
list in Appendix I for the monitoring programs required at
Secs. 192.02(c)(1), 192.03, and 192.12(c)(1). However, the rule still
requires that all hazardous constituents listed in Appendix I be
considered when corrective action is necessary.
IV. Summary of the Final Standard
These final standards consist of three parts: a first part
governing protection against future groundwater contamination from
tailings piles after disposal; a second part that applies to the
cleanup of contamination that occurred before disposal of the tailings
piles; and a third part that provides guidance on implementation and
specifies conditions under which supplemental standards may be applied.
A. The Groundwater Standard for Disposal
The standard for protection of groundwater after disposal (subpart
A) is divided into two parts that separately address actions to be
carried out during periods of time designated as the disposal and post-
disposal periods. The disposal and post-disposal periods are defined in
a manner analogous to the closure and post-closure periods,
respectively, in RCRA regulations. However, there are some differences
regarding their duration and the timing of any corrective actions that
may become necessary due to failure of disposal systems to perform as
designed. (Because there are no mineral processing activities currently
at these inactive sites, standards are not needed for an operational
period.) The disposal period, for the purpose of this regulation, is
defined as that period of time beginning on the effective date of the
original Title I part 192 standard for the inactive sites (March 7,
1983) and ending with completion of all actions related to disposal
except post-disposal monitoring and any corrective actions that might
become needed as a result of failure of completed disposal. The post-
disposal period begins with completion of disposal actions and ends
after an appropriate period for the monitoring of groundwater to
confirm the adequacy of the disposal. The groundwater standard
governing the actions to be carried out during the disposal period
incorporates relevant requirements from subpart F of part 264 of this
chapter (Secs. 264.92-264.95). The standard for the post-disposal
period reflects relevant requirements of Sec. 264.111 of this Chapter.
The disposal standard also includes provisions for monitoring and any
necessary corrective action during both disposal and post-disposal
periods. These provisions are essentially the same as those governing
the licensed (Title II) uranium mill tailings sites (40 CFR 192,
subparts D and E; see also the Federal Register notices for those
standards published on April 29, 1983 and on October 7, 1983). Several
additional constituents are regulated, however, in these final Title I
regulations.
These regulations do not change existing requirements at Title I
sites for the period of time disposal must be designed to comply with
the standards, and therefore remain identical to the requirements for
licensed (Title II) sites in this respect. The Agency also recently
promulgated final regulations for spent nuclear fuel, and high level
and transuranic radioactive wastes (40 CFR part 191; 58 FR 66398,
December 20, 1993). Those standards specify a different design period
for compliance (10,000 years versus 1000 years) for two principle
reasons: (1) The level of radioactivity, and therefore the level of
health risk, in the wastes addressed under 40 CFR part 191 is many
orders of magnitude greater than those addressed here. (The
radioactivity of tailings is typically 0.4 to 1.0 nCi/g, 40 CFR part
191 wastes are always greater than 100 nCi/g, and are typically far
higher.) (2) The volume of uranium mill tailings is far greater than
the waste volumes addressed under 40 CFR part 191. The containment that
would be required to meet a 10,000 year requirement is simply not
feasible for the volumes of tailings involved (the option of
underground disposal was addressed and rejected in the original
[[Page 2860]]
rulemakings for the Title I and Title II sites).
These regulations require installation of monitoring systems
upgradient of the point of compliance (i.e., in the uppermost aquifer
upgradient of the edge of the tailings disposal site) or at some other
point adequate to determine background levels of any listed
constituents that occur naturally at the site. The disposal should be
designed to control, to the extent reasonably achievable for 1000 years
and, in any case, for at least 200 years, all listed constituents
identified in residual radioactive materials at the site to levels for
each constituent derived in accordance with Sec. 192.02(c)(3).
Accordingly, the elements of the groundwater protection standard to be
specified for each disposal site include a list of relevant
constituents, the concentration limits for each such constituent, and
the compliance point.
These standards provide for consideration of ACLs if the disposal
cannot reasonably be designed to assure conformance to background
levels (or those in Table 1) over the required term. ACLs can be
granted provided that, after considering practicable corrective
actions, a determination can be made that it satisfies the values given
by implementing the conditions for ACLs under Sec. 192.02(c)(3)(ii).
The standards for Title II sites require use of a liner under new
tailings piles or lateral extensions of existing piles. These standards
for remedial action at the inactive Title I sites do not contain a
similar provision. EPA assumes that the inactive piles will not need to
be enlarged. Several, however, will be relocated. However, unlike
tailings at the Title II sites, which generally may contain large
amounts of process water, the inactive tailings contain little or no
free water. Such tailings, if properly located and stabilized with a
cover adequate to ensure an unsaturated zone, are not likely to require
a liner in order to protect groundwater.
However, a liner would be needed for an initial drying-out period
to meet these groundwater standards if a situation arose where the
tailings initially contained water above the level of specific
retention. For example, tailings to which water was added to facilitate
their removal to a new site (i.e., through slurrying), or for
compaction during disposal. (It is anticipated that piles will never be
moved to areas of high precipitation or situated within a zone of water
table fluctuation.) Section 192.20(a)(3) requires the remedial plan to
address how any such excess water in tailings would be dealt with. In
such circumstances it will normally be necessary to use a liner or
equivalent to assure that groundwater will not be contaminated while
the moisture level in the tailings adjusts to its long-term equilibrium
value. Currently, however, DOE plans do not include slurrying any
tailings to move them to new locations. Further, for all but two sites,
of which one has already been closed (Canonsburg) and at the other
(Falls City) disposal actions are well advanced, the tailings are
located in arid areas where annual precipitation is low.
Disposal designs which prevent migration of listed constituents in
the groundwater for only a short period of time would not provide
appropriate protection. Such approaches simply defer adverse
groundwater effects. Therefore, measures which only modify the gradient
in an aquifer or create barriers (e.g., slurry walls) would not of
themselves provide an adequate disposal.
Section 192.02(d) requires that a site be closed in a manner that
minimizes further maintenance. Depending on the physical properties of
the sites, candidate disposal systems, and the effects of natural
processes over time, measures required to satisfy these standards will
vary from site to site. Actual site data, computational models, and
prevalent expert judgment may be used in deciding that proposed
measures will satisfy the standards. Under the provisions of Section
108(a) of UMTRCA, the adequacy of these judgments is determined by the
NRC.
For the post-disposal period, a groundwater monitoring plan is
required to be developed and implemented. The plan will require
monitoring for a period of time deemed sufficient to verify, with
reasonable assurance, the adequacy of the disposal to achieve its
design objectives for containment of listed constituents. EPA expects
this period of time to be comparable, in most cases, to that required
under Sec. 264.117 of Title 40 for waste sites regulated under RCRA
(i.e., a few decades). However, there may be situations where longer or
shorter periods are appropriate. Installation and commencement of the
monitoring required under Sec. 192.03 will satisfy this EPA standard,
for the purposes of licensing of the site by the NRC.
With regard to this monitoring, UMTRCA provides that, after
remediation is completed and custody is transferred to a Federal
agency, NRC may require that the Federal agency having custody of each
remediated tailings site ``* * * undertake such monitoring,
maintenance, and emergency measures * * *and other actions as [NRC]
deems necessary to comply with [EPA's standards]'' (UMTRCA, Section
104(f)(2)). Although it is not intended that routine monitoring be
carried out as a requirement for conformance to these standards for the
200- to 1000-year period over which the disposal is designed to be
effective, NRC may require more extensive monitoring to comply with
EPA's standards, as NRC deems necessary under Sec. 104(f)(2) of the
Act.
During the post-disposal period, if listed constituents from a
disposal site are detected in excess of the groundwater standards,
these regulations require a corrective action program designed to bring
the disposal and the groundwater into compliance with the provisions of
Sec. 192.02(c)(3) and subpart B, respectively. In designing such a
corrective action program, the implementing agencies may consider all
of the provisions available under subparts A, B, and C. A modification
of the monitoring program sufficient to demonstrate that the corrective
measures will be successful is also required. In designing future
corrective action programs, the implementing agencies may also wish to
consider the guidance provided by new regulations now being developed
for the RCRA program that will be proposed as subpart S to Title 40.
However, the requirements of Part 192 will still govern regulatory
determinations of acceptability.
Additional Regulated Constituents
For the purpose of this regulation only, the Agency is regulating,
in addition to the hazardous constituents referenced by Sec. 264.93,
molybdenum, nitrate, combined radium-226 and radium-228, and combined
uranium-234 and uranium-238. Molybdenum, radium, and uranium were
addressed by the Title II standards because these radioactive and/or
toxic constituents are found in high concentrations at many mill
tailings sites. These regulations add numerical limits for these
constituents. Nitrate was added because it had been identified in
concentrations far in excess of drinking water standards in groundwater
at a number of the inactive sites.
The concentration limit for molybdenum in groundwater from uranium
tailings is set at 0.1 milligram per liter. This is the value of the
provisional Adjusted Acceptable Daily Intake (AADI) for drinking water
developed by EPA under the Safe Drinking Water Act (50 FR 46958). The
Agency has established neither a maximum concentration limit goal
[[Page 2861]]
(MCLG) nor a maximum concentration limit (MCL) for molybdenum because
it occurs only infrequently in water. According to the most recent
relevant report of the National Academy of Sciences (Drinking Water and
Health, 1980, Vol. III), molybdenum from drinking water, except for
highly contaminated sources, is not likely to constitute a significant
portion of the total human intake of this element. However, as noted
above, uranium tailings are often a highly concentrated source of
molybdenum, and it is therefore appropriate to include a standard for
molybdenum in this rule. In addition to the hazard to humans, our
analysis of toxic substances in tailings in the Final Environmental
Impact Statement for Remedial Action Standards for Inactive Uranium
Processing Sites (EPA 520/4-82-013-1) found that, for ruminants,
molybdenum in concentrations greater than 0.05 ppm in drinking water
would lead to chronic toxicity. This concentration included a safety
factor of 10; the standard provides for a safety factor of 5, which we
consider adequately protective for ruminants.
The standard for combined uranium-234 and uranium-238 due to
contamination from uranium tailings is 30 pCi per liter. The level of
health risk associated with this standard is equivalent to the level
proposed as the MCL for uranium in drinking water by EPA (56 FR 33050,
July 18, 1991). The standard promulgated here applies to remedial
actions for uranium tailings only. When the Agency has established a
final MCL for isotopes of uranium in drinking water, we will consider
whether this standard needs to be reviewed.
The limit for nitrate (as nitrogen) is 10 mg per liter. This is the
value of the drinking water standard for nitrate.
B. The Cleanup Standard
With the exception of the point of compliance provision, the
standard (subpart B) for cleanup of contaminated groundwater contains
the same basic provisions as the standard for disposal in subpart A. In
addition, it provides for the establishment of supplemental standards
under certain conditions, and for use of institutional control to
permit passive restoration through natural flushing when no public
water system is involved.
Although the standards specify a single point of compliance for
conformance to the groundwater standards for disposal, this does not
suffice for the cleanup of groundwater that has been contaminated
before final disposal. Instead, in this case compliance must be
achieved anywhere contamination above the levels established by these
standards is found or is projected to be found in groundwater outside
the disposal area and its cover. The standards require DOE to establish
a monitoring program adequate to determine the extent of contamination
(Sec. 192.12(c)(1)) in groundwater around each processing site. The
possible presence of any of the inorganic or organic hazardous
constituents identified in tailings or used in the processing operation
should be assessed. The plan for remedial action referenced under
Sec. 192.20(b)(4) should document the extent of contamination, the rate
and direction of movement of contaminants, and consider future movement
of the plume. The cleanup standards normally require restoration of all
contaminated groundwater to the levels provided for under
Sec. 192.02(c)(3). These levels are either background concentrations,
the levels specified in Table 1 in the rule, or ACLs. In cases where
the groundwater is not classified as of limited use, any ACL should be
determined under the assumption that the groundwater may be used for
drinking purposes. In certain circumstances, however, supplemental
standards set at levels that would be achieved by remedial actions that
come as close to meeting the otherwise applicable standards as is
reasonably achievable under the circumstances may be appropriate. Such
supplemental standards and ACLs are distinct regulatory provisions and
may be considered independently. The regulations provide that
supplemental standards may be granted if:
Groundwater at the site is of limited use (Sec. 192.11(e))
in the absence of contamination from residual radioactive materials; or
Complete restoration would cause more environmental harm
than it would prevent; or
Complete restoration is technically impracticable from an
engineering perspective.
The use of supplemental standards for limited use groundwater
applies the groundwater classification system proposed in EPA's 1984
Groundwater Protection Strategy. As proposed for use in these standards
(52 FR 36003, September 24, 1987), Class III encompasses groundwaters
that are not a current or potential source of drinking water because of
widespread, ambient contamination caused by natural or human-induced
conditions, or cannot provide enough water to meet the needs of an
average household. These standards adopt the proposed definition of
limited use groundwater. However, for the purpose of qualifying for
supplemental standards, human-induced conditions exclude contributions
from residual radioactive materials.
Water which meets the definition of limited use groundwater may,
nevertheless, reasonably be or be projected to be useful for domestic,
agricultural, or industrial purposes. For example, in some locations
higher quality water may be scarce or absent. Therefore, Sec. 192.22(d)
requires the implementing agencies to remove any additional
contamination that has been contributed by residual radioactive
materials to the extent that is necessary to preserve existing or
reasonably projected beneficial uses in areas of limited water
supplies. At a minimum, at sites with limited use groundwater, the
supplemental standards require such management of contamination due to
tailings as is required to assure protection of human health and the
environment from that contamination. For example, if the additional
contamination from the tailings would cause an adverse effect on
drinkable groundwater that has a significant interconnection with
limited use groundwater over which the tailings reside, then the
additional contamination from the tailings will have to be abated.
Supplemental standards are also appropriate in certain other cases
similar to those addressed in Section 121(d)(4) of the Superfund
Amendments and Reauthorization Act of 1986 (SARA). SARA recognizes that
cleanup of contamination could sometimes cause environmental harm
disproportionate to the effects it would alleviate. For example, if
fragile ecosystems would be impaired by any reasonable restoration
process (or by carrying a restoration process to extreme lengths to
remove small amounts of residual contamination), then it might be
prudent not to completely restore groundwater quality. Such a situation
might occur, for example, if the quantity of water that would be lost
during remediation is a significant fraction of that available in an
aquifer that recharges very slowly. Decisions regarding tradeoffs of
environmental damage can only be based on characteristics peculiar to
the specific location of the site. We do not yet know whether such
situations exist in the UMTRCA program, but EPA believes that use of
supplemental standards should be possible in such situations, after
thorough investigation and consideration of all reasonable restoration
alternatives.
[[Page 2862]]
Based on currently available information, we are not aware that at
least substantial restoration of groundwater quality is technically
impracticable from an engineering perspective at any of the designated
sites. However, our information is incomplete. For example, there may
not be enough water available in a very small aquifer to carry out
remediation and retain the groundwater resource, or, in other cases,
some contaminants may not be removable without destroying the aquifer.
EPA believes that DOE should not be required to institute active
measures that would completely restore groundwater at these sites if
such restoration is technically impracticable from an engineering
perspective, and if, at a minimum, protection of human health and the
environment is assured. Consistent with the provisions of SARA for
remediation of waste sites generally, the standards therefore permit
supplemental standards in such situations at levels achievable by site-
specific alternate remedial actions. A finding of technical
impracticability from an engineering perspective requires careful and
extensive documentation, including an analysis of the degree to which
remediation is practicable. It should be noted that the phrase
``technically impracticable from an engineering perspective'' means
that the remedial action cannot reasonably be put into practice; it
does not mean a conclusion derived from the balancing of costs and
benefits. In addition to documentation of technical matters related to
cleanup technology, DOE should also include a detailed assessment of
such site-specific matters as transmissivity of the geologic formation,
aquifer recharge and storage, contaminant properties (e.g., withdrawal
and treatability potential), and the extent of contamination.
Finally, for aquifers where compliance with the groundwater
standards can be projected to occur naturally within a period of less
than 100 years, and where the groundwater is not now used for a public
water system and is not now projected to be so used within this period,
this rule permits extension of the remedial period to that time,
provided institutional control and an adequate verification plan which
assures satisfaction of beneficial uses is established and maintained
throughout this extended remedial period.
Active restoration should be carefully considered when evaluating
the use of such passive restoration. The provision to permit reliance
on natural restoration is based on the judgment that sole reliance on
active cleanup may not always be warranted under these standards
promulgated pursuant to UMTRCA. This may be the case for situations
where active cleansing to completely achieve the standards is
impracticable, environmentally damaging, or excessively costly, if
groundwater can reach the levels required by the standards through
natural flushing within an acceptable period of time. This mechanism
may be considered where groundwater concentration limits can be met
through partial (or complete) reliance on natural processes and no use
of the water as a source for a public water system exists or is
projected. Any institutional control that may be required to
effectively protect public health and the environment and assure that
beneficial uses that the water could have satisfied are provided for in
the interim must be verified for effectiveness and modified as
necessary. Alternate standards are not required where final cleanup is
to be accomplished through natural flushing, since those established
under Sec. 192.02(c)(3) must be met at the end of the remedial period.
The regulations establish a time limit on such extension of the
remedial period to limit reliance on extended use of institutional
controls to manage public access to contaminated groundwater. Following
the precedent established by our rule for high-level radioactive wastes
(40 CFR 191.14(a)), use of institutional controls is permitted for this
purpose only when they will be needed for periods of less than 100
years.
The effectiveness of institutional controls must be verified and
maintained over the entire period of time that they are in use.
Examples of acceptable measures include use restrictions enforceable by
the administrative or judicial branches of government entities, and
measures with a high degree of permanence, such as Federal or State
ownership of the land containing the contaminated water. In some
instances, a combination of institutional controls may be needed to
provide adequate protection, such as providing an alternate source of
water for drinking or other beneficial uses and restricting
inappropriate use of contaminated groundwater. However, institutional
control provisions are not intended to require DOE to provide water for
uses that the groundwater would not have been available or suitable for
in the absence of contamination from residual radioactive materials.
Institutional controls that are not adequate by themselves include such
measures as health advisories, signs, posts, admonitions, or any other
measure that requires the voluntary cooperation of private parties.
However, such measures may be used to complement other enforceable
institutional controls.
Restoration of groundwater may be carried out by removal, wherein
the contaminated water is removed from the aquifer, treated, and either
disposed of, used, or re-injected into the aquifer, and in situ,
through the addition of chemical or biological agents to fix, reduce,
or eliminate the contamination in place. Appropriate restoration will
depend on characteristics of specific sites and may involve use of a
combination of methods. Water can be removed from an aquifer by pumping
it out through wells or by collecting the water from intercept
trenches. Slurry walls can sometimes be put in place to contain
contamination and prevent further migration of contaminants, so that
the volume of contaminated water that must be treated is reduced. The
background information document contains a more extensive discussion of
candidate restoration methods.
Previously EPA reviewed preliminary information for all 24 sites
and detailed information for 14 to make a preliminary assessment of the
extent of the potential applicability of supplemental standards and the
use of passive remediation. Approximately two-thirds of the sites
appear to be located over potable (or otherwise useful) groundwater and
the balance over limited use groundwaters. DOE, based on more recent
information, feels that up to ten sites are candidates for supplemental
standards, and that the rate at which natural flushing is occurring at
up to eight of the sites permits consideration of passive remediation
under institutional control as the sole remedial method. Some sites
exhibit conditions that could be amenable to a combination of
strategies. Further, EPA is not able to predict the applicability of
provisions regarding technical impracticability or excess environmental
harm, since this requires detailed analysis of specific sites, but
anticipates that wide application is unlikely. It is emphasized that
the above assessment is not based on final results for the vast
majority of these sites, and is, therefore, subject to change.
RCRA regulations, for hazardous waste disposal units regulated by
EPA, provide that acceptable concentrations of constituents in
groundwater (including ACLs) are determined by the Regional
Administrator (or an authorized State). EPA's regulations under Title
II of UMTRCA provide that the NRC, which regulates active sites,
replace the EPA Regional Administrator for the above functions when any
[[Page 2863]]
contamination permitted by an ACL will remain on the licensed site or
within 500 meters of the disposal area, whichever is closer. Because
Section 108(a) of UMTRCA requires the Commission's concurrence with
DOE's selection and performance of remedial actions to conform to EPA's
standards, this rule makes the same provision for administration by the
NRC of those functions for Title I as it did in the case of the Title
II standards, and also provides for NRC concurrence on supplemental
standards.
V. Implementation
UMTRCA requires the Secretary of Energy to select and perform the
remedial actions needed to implement these standards, with the full
participation of any State that shares the cost. The NRC must concur
with these actions and, when appropriate, the Secretary of Energy must
also consult with affected Indian tribes and the Secretary of the
Interior.
The cost of remedial actions is being borne by the Federal
Government and the States as prescribed by UMTRCA. The clean-up of
groundwater is a large-scale undertaking for which there is relatively
little long-term experience. Groundwater conditions at the inactive
processing sites vary greatly, and, as noted above, engineering
experience with some of the required remedial actions is limited.
Although preliminary engineering assessments have been performed,
specific engineering requirements and detailed costs to meet the
groundwater standards at each site have yet to be determined. We
believe that costs averaging about 10-15 million (1993) dollars for
each of the approximately fourteen tailings sites at which remedial
action may be required are most likely.
The benefits from the cleanup of this groundwater are difficult to
quantify. In some instances, groundwater that is contaminated by
tailings is now in use and will be restored. Future uses that will be
preserved by cleanup are difficult to project. In the areas where the
tailings were processed, groundwater is an important resource due to
the arid condition of the land. However, much of the contamination at
these sites occurs in shallow alluvial aquifers. At some of these sites
such aquifers have limited use because of their generally poor quality
and the availability of better quality water from deeper aquifers.
Implementation of the disposal standard for protection of
groundwater will require a judgment that the method chosen provides a
reasonable expectation that the provisions of the standard will be met,
to the extent reasonably achievable, for up to 1000 years and, in any
case, for at least 200 years. This judgment will necessarily be based
on site-specific analyses of the properties of the sites, candidate
disposal systems, and the potential effects of natural processes over
time. Therefore, the measures required to satisfy the standard will
vary from site to site. Actual site data, computational models, and
expert judgment will be the major tools in deciding that a proposed
disposal system will satisfy the standard.
The purpose of the groundwater cleanup standard is to provide the
maximum reasonable protection of public health and the environment.
Costs incurred by remedial actions should be directed toward this
purpose. We intend the standards to be implemented using verification
procedures whose cost and technical requirements are reasonable.
Procedures that provide a reasonable assurance of compliance with the
standards will be adequate. Measurements to assess existing
contamination and to determine compliance with the cleanup standards
should be performed with 1 reasonable survey and sampling procedures
designed to minimize the cost of verification.
The explanations regarding implementation of these regulations in
Secs. 192.20(a)(2) and (3) have been revised to remove those provisions
that the Court remanded and to reflect these new requirements.
These standards are not expected to affect the disposal work DOE
has already performed on tailings. On the basis of consultations with
DOE and NRC, we expect, in general, that a pile designed to comply with
the disposal standards proposed on September 24, 1987, will also comply
with these disposal standards for the control of groundwater
contamination. DOE will have to determine, with the concurrence of the
NRC, what additional work may be needed to comply with the groundwater
cleanup requirements. However, any such cleanup work should not
adversely affect the control systems for tailings piles that have
already been or are currently being installed.
However, at three sites (Canonsburg, PA; Shiprock, NM; and Salt
Lake City, UT) the disposal design was based on standards remanded in
part on September 3, 1985. We have considered these sites separately,
based on information supplied by DOE, and reached the tentative
conclusion that modification of the existing disposal cells is not
warranted at any of them. Final determinations will be made by DOE,
with the concurrence of NRC.
The disposal site at Canonsburg, PA, is located above the banks of
Chartiers Creek. Contamination that might seep from the encapsulated
tailings will reach the surface within the site boundary, and is then
diluted by water in the creek to insignificant levels. Under these
circumstances, this site qualifies for an ACL under
Sec. 192.02(c)(3)(ii), and modification of the existing disposal cell
is not warranted.
The site at Shiprock, NM, which is located above the floodplain of
the San Juan River, is over an aquifer that may not be useful as a
source of water for drinking or other beneficial purpose because of its
quality, areal extent, and yield. Most of the groundwater in this
aquifer appears to have originated from seepage of tailings liquor from
mill impoundments and not to be contributing to contamination of any
currently or potentially useful aquifer. Additionally, the quality of
this water may be degraded by uncontrolled disposal of municipal refuse
north and south of the site. DOE is currently in the process of
completing its characterization of this groundwater, and may or may not
recommend use of a supplemental standard under Sec. 192.21(g). In any
case, however, it appears unlikely that modification of the existing
disposal cell will be necessary.
The site containing the tailings from the Salt Lake City mill is
located at Clive, Utah, over groundwater that contains dissolved solids
in excess of 10,000 mg/l and is not contributing to contamination of
any currently or potentially useful aquifer. Under these circumstances,
this site also qualifies for a supplemental standard under
Sec. 192.21(g), and modification of the existing disposal cell is not
warranted.
VI. Relationship to Other Policy and Requirements
In July 1991 EPA completed development of a strategy to guide
future EPA and State activities in groundwater protection and cleanup.
A key element of this strategy is a statement of `EPA Groundwater
Protection Principles' \1\ that has as its overall goals the prevention
of adverse effects on human health and the environment and protection
of the environmental integrity of the nation's groundwater resources.
To achieve these
[[Page 2864]]
goals, EPA developed principles regarding prevention; remediation; and
Federal, State, and local responsibilities. These principles are set
forth and their implementation by this rule summarized below.
---------------------------------------------------------------------------
\1\ Protecting the Nation's Groundwater: EPA's Strategy for the
1990s, The Final Report of the EPA Groundwater Task Force, U.S.
Environmental Protection Agency, Washington, (Report 21Z-1020), July
1991.
(1) With respect to prevention: groundwater should be protected
to ensure that the nation's currently used and reasonably expected
drinking water supplies, both public and private, do not present
adverse health risks and are preserved for present and future
generations. Groundwater should also be protected to ensure that
groundwater that is closely hydrologically connected to surface
waters does not interfere with the attainment of surface water
quality standards, which is necessary to protect the integrity of
associated ecosystems. Groundwater protection can be achieved
through a variety of means including: pollution prevention programs;
source controls; siting controls; the designation of wellhead
protection areas and future public water supply areas; and the
protection of aquifer recharge areas. Efforts to protect groundwater
must also consider the use, value, and vulnerability of the
---------------------------------------------------------------------------
resource, as well as social and economic values.
This rule for uranium mill tailings protects groundwater by
requiring that disposal piles be designed to avoid any new
contamination of groundwater that would threaten human health or the
environment in the future. Water is scarce in the Western States where
these disposal sites occur. Currently almost half of the water consumed
in Arizona and New Mexico and 20 to 30 percent of the water consumed in
Utah, Colorado, Idaho, and Texas is groundwater. The population in the
Mountain States is expected to increase more than that of any other
region between now and the year 2010. In particular, the population in
Colorado, New Mexico, Arizona, and Utah is expected to increase
dramatically. Thus, in order to ensure that all currently used and
reasonably expected drinking water supplies near these sites, both
public and private, are adequately protected for use by present and
future generations, these rules apply drinking water standards to all
potable groundwater. The rule also requires that hydrologically-
connected aquifers and surface waters, including designated wellhead
protection areas and future public water supply areas, be identified
and protected, and that other beneficial uses of groundwater besides
drinking be identified and protected, including the integrity of
associated ecosystems. In this regard we note that DOE has not
identified any critical aquatic habitats that have been or could be
adversely affected by contamination from these sites.
(2) With respect to remediation: groundwater remediation
activities must be prioritized to limit the risk of adverse effects
to human health risks first and then to restore currently used and
reasonably expected sources of drinking water and groundwater
closely hydrologically connected to surface waters, whenever such
restorations are practicable and attainable.
Pursuant to our responsibilities under Section 102(b) of UMTRCA,
EPA advised DOE in 1979 concerning the criteria which should govern the
order in which these sites should be cleaned up. Those criteria
specified, in essence, that sites capable of affecting the health of
human populations the most should be remediated first. As a result DOE
has divided the 24 sites into three levels of priority, based on the
populations affected. In order to facilitate implementation of these
principles, we have, in this rule, provided DOE with flexibility to
prioritize their cleanup activities so as to first minimize human
exposure, then restore reasonably expected drinking water sources, and
finally to clean up groundwater only when restoration is practicable
and attainable. This has been done by relaxing the requirements for
cleanup of water:
(a) If it is not a current or potential source of drinking water
(i.e., it meets the definition of limited use),
(b) Where natural processes will achieve the standards and there is
no current or planned use,
(c) Where adverse environmental impact will occur, and (d) where
cleanup is technologically impracticable.
(3) With respect to Federal, State, and local responsibilities:
the primary responsibility for coordinating and implementing
groundwater protection programs has always been and should continue
to be vested with the States. An effective groundwater protection
program should link Federal, State, and local activities into a
coherent and coordinated plan of action. EPA should continue to
improve coordination of groundwater protection efforts within the
Agency and with other Federal agencies with groundwater
responsibilities.
In the case of the sites covered by these regulations, UMTRCA
specifies a primary role for Federal rather than State agencies.
However, since these regulations are modeled after existing RCRA
regulations, this will serve to insure coherence and coordination with
similar prevention and remediation actions by EPA, the States, and
other Federal agencies. For example, the concentration limits in
groundwater for listed constituents at the sites covered by this rule
are the same as those specified for cleanup and disposal at RCRA sites
by EPA and the States and at uranium mill sites licensed by NRC.
Executive Order 12866
Under Executive Order 12866 (58 FR 51735; October 4, 1993), EPA
must determine whether a rule is ``significant'' and therefore subject
to review by the Office of Management and Budget (OMB) 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 effect in a material way the economy, a sector of the
economy, productivity, 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 the
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 may be a ``significant regulatory
action,'' because it may qualify under criterion #4 above on the basis
of comments submitted to EPA by letter on January 15, 1993, as a result
of OMB review under the previous Executive Order 12291. This action was
therefore resubmitted to OMB for review. Comments from OMB to EPA for
their review under the previous Executive Order and EPA's response to
those comments are included in the docket. Any changes made in response
to OMB suggestions or recommendations as a result of the current review
will be documented in the public record.
Paperwork Reduction Act
Under the Paperwork Reduction Act of 1986, the Agency is required
to state the information collection requirements of any standard
published on or after July 1, 1988. In response to this requirement,
this standard contains no information collection requirements and
imposes no reporting burden on the public.
List of Subjects in 40 CFR Part 192
Environmental protection, Groundwater, Radiation protection,
Uranium.
[[Page 2865]]
Dated: December 14, 1994.
Carol M. Browner,
Administrator, Environmental Protection Agency.
For the reasons set forth in the preamble, 40 CFR part 192 is
amended as follows:
PART 192--HEALTH AND ENVIRONMENTAL PROTECTION STANDARDS FOR URANIUM
AND THORIUM MILL TAILINGS
1. The authority citation for part 192 continues to read as
follows:
Authority: Section 275 of the Atomic Energy Act of 1954, 42
U.S.C. 2022, as added by the Uranium Mill Tailings Radiation Control
Act of 1978, Pub. L. 95-604, as amended.
Subpart A--Standards for the Control of Residual Radioactive
Materials From Inactive Uranium Processing Sites
2. Section 192.01 is amended by revising paragraphs (a) and (e) and
adding paragraphs (g) through (r) to read as follows:
Sec. 192.01 Definitions.
(a) Residual radioactive material means:
(1) Waste (which the Secretary determines to be radioactive) in the
form of tailings resulting from the processing of ores for the
extraction of uranium and other valuable constituents of the ores; and
(2) Other wastes (which the Secretary determines to be radioactive)
at a processing site which relate to such processing, including any
residual stock of unprocessed ores or low-grade materials.
* * * * *
(e) Depository site means a site (other than a processing site)
selected under Section 104(b) or 105(b) of the Act.
* * * * *
(g) Act means the Uranium Mill Tailings Radiation Control Act of
1978, as amended.
(h) Administrator means the Administrator of the Environmental
Protection Agency.
(i) Secretary means the Secretary of Energy.
(j) Commission means the Nuclear Regulatory Commission.
(k) Indian tribe means any tribe, band, clan, group, pueblo, or
community of Indians recognized as eligible for services provided by
the Secretary of the Interior to Indians.
(l) Processing site means:
(1) Any site, including the mill, designated by the Secretary under
Section 102(a)(1) of the Act; and
(2) Any other real property or improvement thereon which is in the
vicinity of such site, and is determined by the Secretary, in
consultation with the Commission, to be contaminated with residual
radioactive materials derived from such site.
(m) Tailings means the remaining portion of a metal-bearing ore
after some or all of such metal, such as uranium, has been extracted.
(n) Disposal period means the period of time beginning March 7,
1983 and ending with the completion of all subpart A requirements
specified under a plan for remedial action except those specified in
Sec. 192.03 and Sec. 192.04.
(o) Plan for remedial action means a written plan (or plans) for
disposal and cleanup of residual radioactive materials associated with
a processing site that incorporates the results of site
characterization studies, environmental assessments or impact
statements, and engineering assessments so as to satisfy the
requirements of subparts A and B of this part. The plan(s) shall be
developed in accordance with the provisions of Section 108(a) of the
Act with the concurrence of the Commission and in consultation, as
appropriate, with the Indian Tribe and the Secretary of Interior.
(p) Post-disposal period means the period of time beginning
immediately after the disposal period and ending at termination of the
monitoring period established under Sec. 192.03.
(q) Groundwater means water below the ground surface in a zone of
saturation.
(r) Underground source of drinking water means an aquifer or its
portion:
(1)(i) Which supplies any public water system as defined in
Sec. 141.2 of this chapter; or
(ii) Which contains a sufficient quantity of groundwater to supply
a public water system; and
(A) Currently supplies drinking water for human consumption; or
(B) Contains fewer than 10,000 mg/l total dissolved solids; and
(2) Which is not an exempted aquifer as defined in Sec. 144.7 of
this chapter.
3. Section 192.02 is revised to read as follows:
Sec. 192.02 Standards.
Control of residual radioactive materials and their listed
constituents shall be designed \1\ to:
---------------------------------------------------------------------------
\1\ Because the standard applies to design, monitoring after
disposal is not required to demonstrate compliance with respect to
Sec. 192.02(a) and (b).
---------------------------------------------------------------------------
(a) Be effective for up to one thousand years, to the extent
reasonably achievable, and, in any case, for at least 200 years, and,
(b) Provide reasonable assurance that releases of radon-222 from
residual radioactive material to the atmosphere will not:
(1) Exceed an average \2\ release rate of 20 picocuries per square
meter per second, or
---------------------------------------------------------------------------
\2\ This average shall apply over the entire surface of the
disposal site and over at least a one-year period. Radon will come
from both residual radioactive materials and from materials covering
them. Radon emissions from the covering materials should be
estimated as part of developing a remedial action plan for each
site. The standard, however, applies only to emissions from residual
radioactive materials to the atmosphere.
---------------------------------------------------------------------------
(2) Increase the annual average concentration of radon-222 in air
at or above any location outside the disposal site by more than one-
half picocurie per liter.
(c) Provide reasonable assurance of conformance with the following
groundwater protection provisions:
(1) The Secretary shall, on a site-specific basis, determine which
of the constituents listed in Appendix I to Part 192 are present in or
reasonably derived from residual radioactive materials and shall
establish a monitoring program adequate to determine background levels
of each such constituent in groundwater at each disposal site.
(2) The Secretary shall comply with conditions specified in a plan
for remedial action which includes engineering specifications for a
system of disposal designed to ensure that constituents identified
under paragraph (c)(1) of this section entering the groundwater from a
depository site (or a processing site, if residual radioactive
materials are retained on the site) will not exceed the concentration
limits established under paragraph (c)(3) of this section (or the
supplemental standards established under Sec. 192.22) in the uppermost
aquifer underlying the site beyond the point of compliance established
under paragraph (c)(4) of this section.
(3) Concentration limits:
(i) Concentration limits shall be determined in the groundwater for
listed constituents identified under paragraph (c)(1) of this section.
The concentration of a listed constituent in groundwater must not
exceed:
(A) The background level of that constituent in the groundwater; or
(B) For any of the constituents listed in Table 1 to subpart A, the
respective value given in that Table if the background level of the
constituent is below the value given in the Table; or
(C) An alternate concentration limit established pursuant to
paragraph (c)(3)(ii) of this section.
(ii)(A) The Secretary may apply an alternate concentration limit
if, after
[[Page 2866]]
considering remedial or corrective actions to achieve the levels
specified in paragraphs (c)(3)(i)(A) and (B) of this section, he has
determined that the constituent will not pose a substantial present or
potential hazard to human health and the environment as long as the
alternate concentration limit is not exceeded, and the Commission has
concurred.
(B) In considering the present or potential hazard to human health
and the environment of alternate concentration limits, the following
factors shall be considered:
(1) Potential adverse effects on groundwater quality, considering:
(i) The physical and chemical characteristics of constituents in
the residual radioactive material at the site, including their
potential for migration;
(ii) The hydrogeological characteristics of the site and
surrounding land;
(iii) The quantity of groundwater and the direction of groundwater
flow;
(iv) The proximity and withdrawal rates of groundwater users;
(v) The current and future uses of groundwater in the region
surrounding the site;
(vi) The existing quality of groundwater, including other sources
of contamination and their cumulative impact on the groundwater
quality;
(vii) The potential for health risks caused by human exposure to
constituents;
(viii) The potential damage to wildlife, crops, vegetation, and
physical structures caused by exposure to constituents;
(ix) The persistence and permanence of the potential adverse
effects;
(x) The presence of underground sources of drinking water and
exempted aquifers identified under Sec. 144.7 of this chapter; and
(2) Potential adverse effects on hydraulically-connected surface-
water quality, considering:
(i) The volume and physical and chemical characteristics of the
residual radioactive material at the site;
(ii) The hydrogeological characteristics of the site and
surrounding land;
(iii) The quantity and quality of groundwater, and the direction of
groundwater flow;
(iv) The patterns of rainfall in the region;
(v) The proximity of the site to surface waters;
(vi) The current and future uses of surface waters in the region
surrounding the site and any water quality standards established for
those surface waters;
(vii) The existing quality of surface water, including other
sources of contamination and their cumulative impact on surface water
quality;
(viii) The potential for health risks caused by human exposure to
constituents;
(ix) The potential damage to wildlife, crops, vegetation, and
physical structures caused by exposure to constituents; and
(x) The persistence and permanence of the potential adverse
effects.
(4) Point of compliance: The point of compliance is the location at
which the groundwater concentration limits of paragraph (c)(3) of this
section apply. The point of compliance is the intersection of a
vertical plane with the uppermost aquifer underlying the site, located
at the hydraulically downgradient limit of the disposal area plus the
area taken up by any liner, dike, or other barrier designed to contain
the residual radioactive material.
(d) Each site on which disposal occurs shall be designed and
stabilized in a manner that minimizes the need for future maintenance.
4. Section 192.03 is added to read as follows:
Sec. 192.03 Monitoring.
A groundwater monitoring plan shall be implemented, to be carried
out over a period of time commencing upon completion of remedial
actions taken to comply with the standards in Sec. 192.02, and of a
duration which is adequate to demonstrate that future performance of
the system of disposal can reasonably be expected to be in accordance
with the design requirements of Sec. 192.02(c). This plan and the
length of the monitoring period shall be modified to incorporate any
corrective actions required under Sec. 192.04 or Sec. 192.12(c).
5. Section 192.04 is added to read as follows:
Sec. 192.04 Corrective Action.
If the groundwater concentration limits established for disposal
sites under provisions of Sec. 192.02(c) are found or projected to be
exceeded, a corrective action program shall be placed into operation as
soon as is practicable, and in no event later than eighteen (18) months
after a finding of exceedance. This corrective action program will
restore the performance of the system of disposal to the original
concentration limits established under Sec. 192.02(c)(3), to the extent
reasonably achievable, and, in any case, as a minimum shall:
(a) Conform with the groundwater provisions of Sec. 192.02(c)(3),
and
(b) Clean up groundwater in conformance with subpart B, modified as
appropriate to apply to the disposal site.
6. Table 1 is added to subpart A to read as follows:
Table 1 to Subpart A.--Maximum Concentration of Constituents for
Groundwater Protection
------------------------------------------------------------------------
Constituent concentration \1\ Maximum
------------------------------------------------------------------------
Arsenic................................. 0.05
Barium.................................. 1.0
Cadmium................................. 0.01
Chromium................................ 0.05
Lead.................................... 0.05
Mercury................................. 0.002
Selenium................................ 0.01
Silver.................................. 0.05
Nitrate (as N).......................... 10.
Molybdenum.............................. 0.1
Combined radium-226 and radium-228...... 5 pCi/liter
Combined uranium-234 and uranium-238 \2\ 30 pCi/liter
Gross alpha-particle activity (excluding 15 pCi/liter
radon and uranium).
Endrin (1,2,3,4,10,10-hexachloro-6,7- 0.0002
exposy-1,4,4a,5,6,7,8,8a-octahydro-1,4-
endo,endo-5,8-dimethanonaphthalene).
Lindane (1,2,3,4,5,6- 0.004
hexachlorocyclohexane, gamma insomer).
Methoxychlor (1,1,1-trichloro-2,2'-bis(p- 0.1
methoxyphenylethane)).
Toxaphene (C10H10Cl6, technical 0.005
chlorinated camphene, 67-69 percent
chlorine).
2,4-D (2,4-dichlorophenoxyacetic acid).. 0.1
2,4,5-TP Silvex (2,4,5- 0.01
trichlorophenoxypropionic acid).
------------------------------------------------------------------------
\1\ Milligrams per liter, unless stated otherwise.
\2\ Where secular equilibrium obtains, this criterion will be satisfied
by a concentration of 0.044 milligrams per liter (0.044 mg/l). For
conditions of other than secular equilibrium, a corresponding value
may be derived and applied, based on the measured site-specific ratio
of the two isotopes of uranium.
Subpart B--Standards for Cleanup of Land and Buildings Contaminated
with Residual Radioactive Materials from Inactive Uranium
Processing Sites
7. Section 192.11 is amended by revising paragraph (a) and adding
paragraph (e) to read as follows:
192.11 Definitions.
(a) Unless otherwise indicated in this subpart, all terms shall
have the same meaning as defined in subpart A.
* * * * *
[[Page 2867]]
(e) Limited use groundwater means groundwater that is not a current
or potential source of drinking water because (1) the concentration of
total dissolved solids is in excess of 10,000 mg/l, or (2) widespread,
ambient contamination not due to activities involving residual
radioactive materials from a designated processing site exists that
cannot be cleaned up using treatment methods reasonably employed in
public water systems, or (3) the quantity of water reasonably available
for sustained continuous use is less than 150 gallons per day. The
parameters for determining the quantity of water reasonably available
shall be determined by the Secretary with the concurrence of the
Commission.
8. In Sec. 192.12, the introductory text is republished without
change and paragraph (c) is added to read as follows:
192.12 Standards.
Remedial actions shall be conducted so as to provide reasonable
assurance that, as a result of residual radioactive materials from any
designated processing site:
* * * * *
(c) The Secretary shall comply with conditions specified in a plan
for remedial action which provides that contamination of groundwater by
listed constituents from residual radioactive material at any
designated processing site (Sec. 192.01(1)) shall be brought into
compliance as promptly as is reasonably achievable with the provisions
of Sec. 192.02(c)(3) or any supplemental standards established under
Sec. 192.22. For the purposes of this subpart:
(1) A monitoring program shall be carried out that is adequate to
define backgroundwater quality and the areal extent and magnitude of
groundwater contamination by listed constituents from residual
radioactive materials (Sec. 192.02(c)(1)) and to monitor compliance
with this subpart. The Secretary shall determine which of the
constituents listed in Appendix I to part 192 are present in or could
reasonably be derived from residual radioactive material at the site,
and concentration limits shall be established in accordance with
Sec. 192.02(c)(3).
(2) (i) If the Secretary determines that sole reliance on active
remedial procedures is not appropriate and that cleanup of the
groundwater can be more reasonably accomplished in full or in part
through natural flushing, then the period for remedial procedures may
be extended. Such an extended period may extend to a term not to exceed
100 years if:
(A) The concentration limits established under this subpart are
projected to be satisfied at the end of this extended period,
(B) Institutional control, having a high degree of permanence and
which will effectively protect public health and the environment and
satisfy beneficial uses of groundwater during the extended period and
which is enforceable by the administrative or judicial branches of
government entities, is instituted and maintained, as part of the
remedial action, at the processing site and wherever contamination by
listed constituents from residual radioactive materials is found in
groundwater, or is projected to be found, and
(C) The groundwater is not currently and is not now projected to
become a source for a public water system subject to provisions of the
Safe Drinking Water Act during the extended period.
(ii) Remedial actions on groundwater conducted under this subpart
may occur before or after actions under Section 104(f)(2) of the Act
are initiated.
(3) Compliance with this subpart shall be demonstrated through the
monitoring program established under paragraph (c)(1) of this section
at those locations not beneath a disposal site and its cover where
groundwater contains listed constituents from residual radioactive
material.
Subpart C--Implementation
9. In Sec. 192.20, paragraphs (a)(2) and (a)(3) and the first
sentence of paragraph (b)(l) are revised and paragraphs (a)(4) and
(b)(4) are added to read as follows:
192.20 Guidance for implementation.
* * * * *
(a)(1) * * *
(2) Protection of water should be considered on a case-specific
basis, drawing on hydrological and geochemical surveys and all other
relevant data. The hydrologic and geologic assessment to be conducted
at each site should include a monitoring program sufficient to
establish background groundwater quality through one or more upgradient
or other appropriately located wells. The groundwater monitoring list
in Appendix IX of part 264 of this chapter (plus the additional
constituents in Table A of this paragraph) may be used for screening
purposes in place of Appendix I of part 192 in the monitoring program.
New depository sites for tailings that contain water at greater than
the level of ``specific retention'' should use aliner or equivalent. In
considering design objectives for groundwater protection, the
implementing agencies should give priority to concentration levels in
the order listed under Sec. 192.02(c)(3)(i). When considering the
potential for health risks caused by human exposure to known or
suspected carcinogens, alternate concentration limits pursuant to
paragraph 192.02(c)(3)(ii) should be established at concentration
levels which represent an excess lifetime risk, at a point of exposure,
to an average individual no greater than between 10-4 and 10-
6.
Table A to Sec. 192.20(a)(2)--Additional Listed Constituents
Nitrate (as N)
Molybdenum
Combined radium-226 and radium-228
Combined uranium-234 and uranium-238
Gross alpha-particle activity (excluding radon and uranium)
(3) The plan for remedial action, concurred in by the Commission,
will specify how applicable requirements of subpart A are to be
satisfied. The plan should include the schedule and steps necessary to
complete disposal operations at the site. It should include an estimate
of the inventory of wastes to be disposed of in the pile and their
listed constituents and address any need to eliminate free liquids;
stabilization of the wastes to a bearing capacity sufficient to support
the final cover; and the design and engineering specifications for a
cover to manage the migration of liquids through the stabilized pile,
function without maintenance, promote drainage and minimize erosion or
abrasion of the cover, and accommodate settling and subsidence so that
cover integrity is maintained. Evaluation of proposed designs to
conform to subpart A should be based on realistic technical judgments
and include use of available empirical information. The consideration
of possible failure modes and related corrective actions should be
limited to reasonable failure assumptions, with a demonstration that
the disposal design is generally amenable to a range of corrective
actions.
(4) The groundwater monitoring list in Appendix IX of part 264 of
this chapter (plus the additional constituents in Table A in paragraph
(a)(2) of this section) may be used for screening purposes in place of
Appendix I of part 192 in monitoring programs. The monitoring plan
required under Sec. 192.03 should be designed to include verification
of site-specific assumptions used to project the performance of the
disposal system. Prevention of
[[Page 2868]]
contamination of groundwater may be assessed by indirect methods, such
as measuring the migration of moisture in the various components of the
cover, the tailings, and the area between the tailings and the nearest
aquifer, as well as by direct monitoring of groundwater. In the case of
vicinity properties (Sec. 192.01(l)(2)), such assessments may not be
necessary, as determined by the Secretary, with the concurrence of the
Commission, considering such factors as local geology and the amount of
contamination present. Temporary excursions from applicable limits of
groundwater concentrations that are attributable to a disposal
operation itself shall not constitute a basis for considering
corrective action under Sec. 192.04 during the disposal period, unless
the disposal operation is suspended prior to completion for other than
seasonal reasons.
(b)(l) Compliance with Sec. 192.12(a) and (b) of subpart B, to the
extent practical, should be demonstrated through radiation surveys. * *
*
* * * * *
(4) The plan(s) for remedial action will specify how applicable
requirements of subpart B would be satisfied. The plan should include
the schedule and steps necessary to complete the cleanup of groundwater
at the site. It should document the extent of contamination due to
releases prior to final disposal, including the identification and
location of listed constituents and the rate and direction of movement
of contaminated groundwater, based upon the monitoring carried out
under Sec. 192.12(c)(1). In addition, the assessment should consider
future plume movement, including an evaluation of such processes as
attenuation and dilution and future contamination from beneath a
disposal site. Monitoring for assessment and compliance purposes should
be sufficient to establish the extent and magnitude of contamination,
with reasonable assurance, through use of a carefully chosen minimal
number of sampling locations. The location and number of monitoring
wells, the frequency and duration of monitoring, and the selection of
indicator analytes for long-term groundwater monitoring, and, more
generally, the design and operation of the monitoring system, will
depend on the potential for risk to receptors and upon other factors,
including characteristics of the subsurface environment, such as
velocity of groundwater flow, contaminant retardation, time of
groundwater or contaminant transit to receptors, results of statistical
evaluations of data trends, and modeling of the dynamics of the
groundwater system. All of these factors should be incorporated into
the design of a site-specific monitoring program that will achieve the
purpose of the regulations in this subpart in the most cost-effective
manner. In the case of vicinity properties (Sec. 192.01(l)(2)), such
assessments will usually not be necessary. The Secretary, with the
concurrence of the Commission, may consider such factors as local
geology and amount of contamination present in determining criteria to
decide when such assessments are needed. In cases where
Sec. 192.12(c)(2) is invoked, the plan should include a monitoring
program sufficient to verify projections of plume movement and
attenuation periodically during the extended cleanup period. Finally,
the plan should specify details of the method to be used for cleanup of
groundwater.
10. In Sec. 192.21, the introductory text and paragraph (b) are
revised, paragraph (f) is redesignated as paragraph (h), and new
paragraphs (f) and (g) are added to read as follows:
Sec. 192.21 Criteria for applying supplemental standards
Unless otherwise indicated in this subpart, all terms shall have
the same meaning as defined in Title I of the Act or in subparts A and
B. The implementing agencies may (and in the case of paragraph (h) of
this section shall) apply standards under Sec. 192.22 in lieu of the
standards of subparts A or B if they determine that any of the
following circumstances exists:
* * * * *
(b) Remedial actions to satisfy the cleanup standards for land,
Sec. 192.12(a), and groundwater, Sec. 192.12(c), or the acquisition of
minimum materials required for control to satisfy Secs. 192.02(b) and
(c), would, notwithstanding reasonable measures to limit damage,
directly produce health and environmental harm that is clearly
excessive compared to the health and environmental benefits, now or in
the future. A clear excess of health and environmental harm is harm
that is long-term, manifest, and grossly disproportionate to health and
environmental benefits that may reasonably be anticipated.
* * * * *
(f) The restoration of groundwater quality at any designated
processing site under Sec. 192.12(c) is technically impracticable from
an engineering perspective.
(g) The groundwater meets the criteria of Sec. 192.11(e).
* * * * *
11. In Sec. 192.22, paragraphs (a) and (b) are revised and
paragraph (d) is added to read as follows:
192.22 Supplemental standards.
* * * * *
(a) When one or more of the criteria of Sec. 192.21(a) through (g)
applies, the Secretary shall select and perform that alternative
remedial action that comes as close to meeting the otherwise applicable
standard under Sec. 192.02(c)(3) as is reasonably achievable.
(b) When Sec. 192.21(h) applies, remedial actions shall reduce
other residual radioactivity to levels that are as low as is reasonably
achievable and conform to the standards of subparts A and B to the
maximum extent practicable.
* * * * *
(d) When Sec. 192.21(b), (f), or (g) apply, implementing agencies
shall apply any remedial actions for the restoration of contamination
of groundwater by residual radioactive materials that is required to
assure, at a minimum, protection of human health and the environment.
In addition, when Sec. 192.21(g) applies, supplemental standards shall
ensure that current and reasonably projected uses of the affected
groundwater are preserved.
12. Appendix I is added to part 192 to read as follows:
Appendix I to Part 192--Listed Constituents
Acetonitrile
Acetophenone (Ethanone, 1-phenyl)
2-Acetylaminofluorene (Acetamide, N-9H-fluoren-2-yl-)
Acetyl chloride
1-Acetyl-2-thiourea (Acetamide, N-(aminothioxymethyl)-)
Acrolein (2-Propenal)
Acrylamide (2-Propenamide)
Acrylonitrile (2-Propenenitrile)
Aflatoxins
Aldicarb (Propenal, 2-methyl-2-(methylthio)-,O-
[(methylamino)carbonyl]oxime
Aldrin (1,4:5,8-Dimethanonaphthalene, 1,2,3,4,10,10-hexachloro-
1,4,4a,5,8,8a-
hexahydro(1,4,4a,5,8,8
)-)
Allyl alcohol (2-Propen-1-ol)
Allyl chloride (1-Propane,3-chloro)
Aluminum phosphide
4-Aminobiphenyl ([1,1'-Biphenyl]-4-amine)
5-(Aminomethyl)-3-isoxazolol (3(2H)-Isoxazolone,5-(aminomethyl)-)
4-Aminopyridine (4-Pyridineamine)
Amitrole (lH-1,2,4-Triazol-3-amine)
Ammonium vanadate (Vanadic acid, ammonium salt)
Aniline (Benzenamine)
Antimony and compounds, N.O.S.\1\
---------------------------------------------------------------------------
\1\ The abbreviation N.O.S. (not otherwise specified) signifies
those members of the general class not specifically listed by name
in this appendix.
---------------------------------------------------------------------------
[[Page 2869]]
Aramite (Sulfurous acid, 2-chloroethyl 2-[4-(1,1-
dimethylethyl)phenoxy]-1-methylethyl ester)
Arsenic and compounds, N.O.S.
Arsenic acid (Arsenic acid H3AsO4)
Arsenic pentoxide (Arsenic oxide As2O5)
Auramine (Benzamine, 4,4'-carbonimidoylbis[N,N-dimethyl-])
Azaserine (L-Serine, diazoacetate (ester))
Barium and compounds, N.O.S.
Barium cyanide
Benz[c]acridine (3,4-Benzacridine)
Benz[a]anthracene (1,2-Benzanthracene)
Benzal chloride (Benzene, dichloromethyl-)
Benzene (Cyclohexatriene)
Benzenearsonic acid (Arsenic acid, phenyl-)
Benzidine ([1,1'-Biphenyl]-4,4'-diamine)
Benzo[b]fluoranthene (Benz[e]acephananthrylene)
Benzo[j]fluoranthene
Benzo[k]fluoranthene
Benzo[a]pyrene
p-Benzoquinone (2,5-Cyclohexadiene-1,4-dione)
Benzotrichloride (Benzene, (trichloro-
methyl)-)
Benzyl chloride (Benzene, (chloromethyl)-)
Beryllium and compounds, N.O.S.
Bromoacetone (2-Propanone, 1-bromo-)
Bromoform (Methane, tribromo-)
4-Bromophenyl phenyl ether (Benzene, l-bromo-4-phenoxy-)
Brucine (Strychnidin-10-one, 2,3-dimeth-
oxy-)
Butyl benzyl phthalate (1,2-Benzenedicarbozylic acid, butyl
phenylmethyl ester)
Cacodylic acid (Arsinic acid, dimethyl)
Cadmium and compounds, N.O.S.
Calcium chromate (Chromic acid H2CrO4, calcium salt)
Calcium cyanide (Ca(CN)2)
Carbon disulfide
Carbon oxyfluoride (Carbonic difluoride)
Carbon tetrachloride (Methane, tetrachloro-)
Chloral (Acetaldehyde, trichloro-)
Chlorambucil (Benzenebutanoic acid, 4-[bis(2-chloroethyl)amino]-)
Chlordane (4,7-Methano-1H-indene,1,2,4,5,6,7,8,8-octachloro-
2,3,3a,4,7,7a-hexahydro-)
Chlorinated benzenes, N.O.S.
Chlorinated ethane, N.O.S.
Chlorinated fluorocarbons, N.O.S.
Chlorinated naphthalene, N.O.S.
Chlorinated phenol, N.O.S.
Chlornaphazin (Naphthalenamine, N,N'-bis(2-chlorethyl)-)
Chloroacetaldehyde (Acetaldehyde, chloro-)
Chloroalkyl ethers, N.O.S.
p-Chloroaniline (Benzenamine, 4-chloro-)
Chlorobenzene (Benzene, chloro-)
Chlorobenzilate (Benzeneacetic acid, 4-chloro--(4-
chlorophenyl)--hydroxy-, ethyl ester)
p-Chloro-m-cresol (Phenol, 4-chloro-3-methyl)
2-Chloroethyl vinyl ether (Ethene, (2-chloroethoxy)-)
Chloroform (Methane, trichloro-)
Chloromethyl methyl ether (Methane, chloromethoxy-)
-Chloronapthalene (Naphthalene, 2-chloro-)
o-Chlorophenol (Phenol, 2-chloro-)
1-(o-Chlorophenyl)thiourea (Thiourea, (2-chlorophenyl-))
3-Chloropropionitrile (Propanenitrile, 3-chloro-)
Chromium and compounds, N.O.S.
Chrysene
Citrus red No. 2 (2-Naphthalenol, 1-[(2,5-dimethoxyphenyl)azo]-)
Coal tar creosote
Copper cyanide (CuCN)
Creosote
Cresol (Chresylic acid) (Phenol, methyl-)
Crotonaldehyde (2-Butenal)
Cyanides (soluble salts and complexes), N.O.S.
Cyanogen (Ethanedinitrile)
Cyanogen bromide ((CN)Br)
Cyanogen chloride ((CN)Cl)
Cycasin (beta-D-Glucopyranoside, (methyl-ONN-azoxy)methyl)
2-Cyclohexyl-4,6-dinitrophenol (Phenol, 2-cyclohexyl-4,6-dinitro-)
Cyclophosphamide (2H-1,3,2-Oxazaphosphorin-2-amine,N,N-bis(2-
chloroethyl)
tetrahydro-,2-oxide)
2,4-D and salts and esters (Acetic acid, (2,4-dichlorophenoxy)-)
Daunomycin (5,12-Naphthacenedione,8-acetyl-10-[(3-amino-2,3,6-
trideoxy--Llyxo-hexopyranosyl)oxy]-7,8,9,10-tetrahydro-
6,8,11-trihydroxy-1-methoxy-,(8S-cis))
DDD (Benzene, 1,1'-(2,2-dichloroethylidene)bis[4-chloro-)
DDE (Benzene, 1,1-(dichloroethylidene)bis[4-chloro-)
DDT (Benzene, 1,1'-(2,2,2-trichloroethlyidene)bis[4-chloro-)
Diallate (Carbomothioic acid, bis(1-methylethyl)-,S-(2,3-dichloro-2-
propenyl) ester)
Dibenz[a,h]acridine
Dibenz[a,j]acridine
Dibenz[a,h]anthracene
7H-Dibenzo[c,g]carbazole
Dibenzo[a,e]pyrene (Naphtho[1,2,4,5-def)crysene)
Dibenzo[a,h]pyrene (Dibenzo[b,def]crysene)
Dibenzo[a,i]pyrene (Benzo[rst]pentaphene)
1,2-Dibromo-3-chloropropane (Propane, 1,2-dibromo-3-chloro-)
Dibutylphthalate (1,2-Benzenedicarboxylic acid, dibutyl ester)
o-Dichlorobenzene (Benzene, 1,2-dichloro-)
m-Dichlorobenzene (Benzene, 1,3-dichloro-)
p-Dichlorobenzene (Benzene, 1,4-dichloro-)
Dichlorobenzene, N.O.S. (Benzene; dichloro-, N.O.S.)
3,3'-Dichlorobenzidine ([1,1'-Biphenyl]-4,4'-diamine, 3,3'-dichloro-
)
1,4-Dichloro-2-butene (2-Butene, 1,4-dichloro-)
Dichlorodifluoromethane (Methane, dichlorodifluoro-)
Dichloroethylene, N.O.S.
1,1-Dichloroethylene (Ethene, 1,1-dichloro-)
1,2-Dichloroethylene (Ethene, 1,2-dichloro-,(E)-)
Dichloroethyl ether (Ethane, 1,1'-oxybis[2-chloro-)
Dichloroisopropyl ether (Propane, 2,2'-oxybis[2-chloro-)
Dichloromethoxy ethane (Ethane, 1,1'-[methylenebis(oxy)bis[2-chloro-
)
Dichloromethyl ether (Methane, oxybis[chloro-)
2,4-Dichlorophenol (Phenol, 2,4-dichloro-)
2,6-Dichlorophenol (Phenol, 2,6-dichloro-)
Dichlorophenylarsine (Arsinous dichloride, phenyl-)
Dichloropropane, N.O.S. (Propane,
dichloro-,)
Dichloropropanol, N.O.S. (Propanol, dichloro-,)
Dichloropropene; N.O.S. (1-Propane, dichloro-,)
1,3-Dichloropropene (1-Propene, 1,3-dichloro-)
Dieldrin (2,7:3,6-Dimethanonaphth[2,3-b]oxirene,3,4,5,6,9,9-
hexachloro-1a,2,2a,3,6,6a,7,7a,octahydro-
,(1a,2,2a,3,6,6a
,7,7a)-)
1,2:3,4-Diepoxybutane (2,2'-Bioxirane)
Diethylarsine (Arsine, diethyl-)
1,4 Diethylene oxide (1,4-Dioxane)
Diethylhexyl phthalate (1,2-Benzenedicarboxlyic acid, bis(2-
ethylhexl) ester)
N,N-Diethylhydrazine (Hydrazine, 1,2-diethyl)
O,O-Diethyl S-methyl dithiophosphate (Phosphorodithioic acid, O,O-
diethyl S-methyl ester)
Diethyl-p-nitrophenyl phosphate (Phosphoric acid, diethyl 4-
nitrophenyl ester)
Diethyl phthalate (1,2-Benzenedicarboxylic acid, diethyl ester)
O,O-Diethyl O-pyrazinyl phosphorothioate (Phosphorothioic acid, O,O-
diethyl O-pyrazinyl ester)
Diethylstilbesterol (Phenol, 4,4'-(1,2-diethyl-1,2-ethenediyl)bis-
,(E)-)
Dihydrosafrole (1,3-Benxodioxole, 5-propyl-)
Diisopropylfluorophosphate (DFP) (Phosphorofluoridic acid, bis(1-
methyl ethyl) ester)
Dimethoate (Phosphorodithioic acid, O,O-dimethyl S-[2-(methylamino)
2-oxoethyl] ester)
3,3'-Dimethoxybenzidine ([1,1'-Biphenyl]-4,4'-diamine, 3,3'-
dimethoxy-)
p-Dimethylaminoazobenzene (Benzenamine, N,N-dimethyl-4-(phenylazo)-)
7,12-Dimethylbenz[a]anthracene (Benz[a]anthracene, 7,12-dimethyl-)
3,3'-Dimethylbenzidine ([1,1'-Biphenyl]-4,4'-diamine, 3,3'-dimethyl-
)
Dimethylcarbamoyl chloride (carbamic chloride, dimethyl-)
1,1-Dimethylhydrazine (Hydrazine, 1,1-dimethyl-)
1,2-Dimethylhydrazine (Hydrazine, 1,2-dimethyl-)
,-Dimethylphenethylamine (Benzeneethanamine,
,-dimethyl-)
2,4-Dimethylphenol (Phenol, 2,4-dimethyl-)
Dimethylphthalate (1,2-Benzenedicarboxylic acid, dimethyl ester)
Dimethyl sulfate (Sulfuric acid, dimethyl ester)
Dinitrobenzene, N.O.S. (Benzene, dinitro-)
4,6-Dinitro-o-cresol and salts (Phenol, 2-methyl-4,6-dinitro-)
2,4-Dinitrophenol (Phenol, 2,4-dinitro-)
2,4-Dinitrotoluene (Benzene, 1-methyl-2,4-dinitro-)
2,6-Dinitrotoluene (Benzene, 2-methyl-1,3-dinitro-)
Dinoseb (Phenol, 2-(1-methylpropyl)-4,6-dinitro-)
Di-n-octyl phthalate (1,2-Benzenedicarboxylic acid, dioctyl ester)
1,4-Dioxane (1,4-Diethyleneoxide)
Diphenylamine (Benzenamine, N-phenyl-)
[[Page 2870]]
1,2-Diphenylhydrazine (Hydrazine, 1,2-diphenyl-)
Di-n-propylnitrosamine (1-Propanamine,N-nitroso-N-propyl-)
Disulfoton (Phosphorodithioic acid, O,O-diethyl S-[2-
(ethylthio)ethyl] ester)
Dithiobiuret (Thioimidodicarbonic diamide [(H2N)C(S)]2NH)
Endosulfan (6,9,Methano-2,4,3-benzodioxathiepin,6,7,8,9,10,10-
hexachloro-1,5,5a,6,9,9ahexahydro,3-oxide)
Endothall (7-Oxabicyclo[2.2.1]heptane-2,3-dicarboxylic acid)
Endrin and metabolites (2,7:3,6-Dimethanonaphth[2,3-
b]oxirene,3,4,5,6,9,9-hexachloro1a,2,2a,3,6,6a,7,7a-octa-
hydro,(1a,2,2a,3,6,6a
,7,7a)-)
Epichlorohydrin (Oxirane, (chloromethyl)-)
Epinephrine (1,2-Benzenediol,4-[1-hydroxy-2-(methylamino)ethyl]-
,(R)-,)
Ethyl carbamate (urethane) (Carbamic acid, ethyl ester)
Ethyl cyanide (propanenitrile)
Ethylenebisdithiocarbamic acid, salts and esters (Carbamodithioic
acid, 1,2-Ethanediylbis-)
Ethylene dibromide (1,2-Dibromoethane)
Ethylene dichloride (1,2-Dichloroethane)
Ethylene glycol monoethyl ether (Ethanol, 2-ethoxy-)
Ethyleneimine (Aziridine)
Ethylene oxide (Oxirane)
Ethylenethiourea (2-Imidazolidinethione)
Ethylidene dichloride (Ethane, 1,1-
Dichloro-)
Ethyl methacrylate (2-Propenoic acid, 2-methyl-, ethyl ester)
Ethylmethane sulfonate (Methanesulfonic acid, ethyl ester)
Famphur (Phosphorothioic acid, O-[4-
[(dimethylamino)sulphonyl]phenyl] O,O-dimethyl ester)
Fluoranthene
Fluorine
Fluoroacetamide (Acetamide, 2-fluoro-)
Fluoroacetic acid, sodium salt (Acetic acid, fluoro-, sodium salt)
Formaldehyde (Methylene oxide)
Formic acid (Methanoic acid)
Glycidylaldehyde (Oxiranecarboxyaldehyde)
Halomethane, N.O.S.
Heptachlor (4,7-Methano-1H-indene, 1,4,5,6,7,8,8-heptachloro-
3a,4,7,7a-tetrahydro-)
Heptachlor epoxide (, , and isomers)
(2,5-Methano-2H-indeno[1,2-b]-oxirene, 2,3,4,5,6,7,7-heptachloro-
1a,1b,5,5a,6,6a-hexa-hydro-
,(1a,1b,2,5,5a,6
,6a)-)
Hexachlorobenzene (Benzene, hexachloro-)
Hexachlorobutadiene (1,3-Butadiene, 1,1,2,3,4,4-hexachloro-)
Hexachlorocyclopentadiene (1,3-Cyclopentadiene, 1,2,3,4,5,5-
hexachloro-)
Hexachlorodibenzofurans
Heptachlorodibenzo-p-dioxins
Hexachloroethane (Ethane, hexachloro-)
Hexachlorophene (phenol, 2,2'-Methylenebis[3,4,6-trichloro-)
Hexachloropropene (1-Propene, 1,1,2,3,3,3-hexachloro-)
Hexaethyl tetraphosphate (Tetraphosphoric acid, hexaethyl ester)
Hydrazine
Hydrocyanic acid
Hydrofluoric acid
Hydrogen sulfide (H2S)
Indeno(1,2,3-cd)pyrene
Isobutyl alcohol (1-Propanol, 2-methyl-)
Isodrin (1,4,5,8-Dimethanonaphthalene, 1,2,3,4,10,10-hexachloro-
1,4,4a,5,8,8a-hexahydro,
(1,4,4a,5,8,8a)
-)
Isosafrole (1,3-Benzodioxole, 5-(1-propenyl)-)
Kepone (1,3,4-Metheno-2H-cyclobuta[cd]pentalen-2-one,
1,1a,3,3a,4,5,5,5a,5b,6-decachlorooctahydro-)
Lasiocarpine (2-Butenoic acid, 2-methyl-,7-[[2,3-dihydroxy-2-(1-
methoxyethyl)-3-methyl-1-oxobutoxy]methyl]-2,3,5,7a-tetrahydro-1H-
pyrrolizin-l-yl ester)
Lead and compounds, N.O.S.
Lead acetate (Acetic acid, lead(2+) salt)
Lead phosphate (Phosphoric acid, lead(2+) salt(2:3))
Lead subacetate (Lead, bis(acetato-O)tetrahydroxytri-)
Lindane (Clohexane, 1,2,3,4,5,6-hexachloro-,
(1,2,3,4,5,6)-
)
Maleic anhydride (2,5-Furandione)
Maleic hydrazide (3,6-Pyridazinedione, 1,2-dihydro-)
Malononitrile (Propanedinitrile)
Melphalan (L-Phenylalanine, 4-[bis(2-chloroethyl)aminol]-)
Mercury and compounds, N.O.S.
Mercury fulminate (Fulminic acid, mercury(2+) salt)
Methacrylonitrile (2-Propenenitrile, 2-methyl-)
Methapyrilene (1,2-Ethanediamine, N,N-dimethyl-N'-2-pyridinyl-N'-(2-
thienylmethyl)-)
Metholmyl (Ethamidothioic acid, N-[[(methylamino)carbonyl]oxy]thio-,
methyl ester)
Methoxychlor (Benzene, 1,1'-(2,2,2-trichloroethylidene)bis[4-
methoxy-)
Methyl bromide (Methane, bromo-)
Methyl chloride (Methane, chloro-)
Methyl chlorocarbonate (Carbonchloridic acid, methyl ester)
Methyl chloroform (Ethane, 1,1,1-trichloro-)
3-Methylcholanthrene (Benz[j]aceanthrylene, 1,2-dihydro-3-methyl-)
4,4'-Methylenebis(2-chloroaniline) (Benzenamine, 4,4'-
methylenebis(2-
chloro-)
Methylene bromide (Methane, dibromo-)
Methylene chloride (Methane, dichloro-)
Methyl ethyl ketone (MEK) (2-Butanone)
Methyl ethyl ketone peroxide (2-Butanone, peroxide)
Methyl hydrazine (Hydrazine, methyl-)
Methyl iodide (Methane, iodo-)
Methyl isocyanate (Methane, isocyanato-)
2-Methyllactonitrile (Propanenitrile, 2-hydroxy-2-methyl-)
Methyl methacrylate (2-Propenoic acid, 2-methyl-, methyl ester)
Methyl methanesulfonate (Methanesulfonic acid, methyl ester)
Methyl parathion (Phosphorothioic acid, O,O-dimethyl O-(4-
nitrophenyl) ester)
Methylthiouracil (4(1H)Pyrimidinone, 2,3-dihydro-6-methyl-2-thioxo-)
Mitomycin C (Azirino[2',3':3,4]pyrrolo[1,2-a]indole-4,7-dione,6-
amino-8-[[(aminocarbonyl) oxy]methyl]-1,1a,2,8,8a,8b-hexahydro-8a-
methoxy-5-methy-, [1aS-
(1a,8,8a,8b)]-)
MNNG (Guanidine, N-methyl-N'-nitro-N-nitroso-)
Mustard gas (Ethane, 1,1'-thiobis[2-chloro-)
Naphthalene
1,4-Naphthoquinone (1,4-Naphthalenedione)
-Naphthalenamine (1-Naphthylamine)
-Naphthalenamine (2-Naphthylamine)
-Naphthylthiourea (Thiourea, 1-naphthalenyl-)
Nickel and compounds, N.O.S.
Nickel carbonyl (Ni(CO)4 (T-4)-)
Nickel cyanide (Ni(CN)2)
Nicotine and salts (Pyridine, 3-(1-methyl-2-pyrrolidinyl)-, (S)-)
Nitric oxide (Nitrogen oxide NO)
p-Nitroaniline (Benzenamine, 4-nitro-)
Nitrobenzene (Benzene, nitro-)
Nitrogen dioxide (Nitrogen oxide NO2)
Nitrogen mustard, and hydrochloride salt (Ethanamine, 2-chloro-N-(2-
chloroethyl)-N-methyl-)
Nitrogen mustard N-oxide and hydrochloride salt (Ethanamine,
2chloro-N-(2-chloroethyl)N-methyl-, N-oxide)
Nitroglycerin (1,2,3-Propanetriol, trinitrate)
p-Nitrophenol (Phenol, 4-nitro-)
2-Nitropropane (Propane, 2-nitro-)
Nitrosamines, N.O.S.
N-Nitrosodi-n-butylamine (l-Butanamine, N-butyl-N-nitroso-)
N-Nitrosodiethanolamine (Ethanol, 2,2'-(nitrosoimino)bis-)
N-Nitrosodiethylamine (Ethanamine, N-ethyl-N-nitroso-1)
N-Nitrosodimethylamine (Methanamine, N-methyl-N-nitroso-)
N-Nitroso-N-ethylurea (Urea, N-ethyl-N-nitroso-)
N-Nitrosomethylethylamine (Ethanamine, N-methyl-N-nitroso-)
N-Nitroso-N-methylurea (Urea, N-methyl-N-nitroso-)
N-Nitroso-N-methylurethane (Carbamic acid, methylnitroso-, ethyl
ester)
N-Nitrosomethylvinylamine (Vinylamine, N-methyl-N-nitroso-)
N-Nitrosomorpholine (Morpholine,
4-nitroso-)
N-Nitrosonornicotine (Pyridine, 3-(1-nitroso-2-pyrrolidinyl)-, (S)-)
N-Nitrosopiperidine (Piperidine, 1-nitroso-)
Nitrosopyrrolidine (Pyrrolidine, 1-nitroso-)
N-Nitrososarcosine (Glycine, N-methyl-N-nitroso-)
5-Nitro-o-toluidine (Benzenamine, 2-methyl-5-nitro-)
Octamethylpyrophosphoramide (Diphosphoramide, octamethyl-)
Osmium tetroxide (Osmium oxide OsO4, (T-4)-)
Paraldehyde (1,3,5-Trioxane, 2,4,6-tri
methyl-)
Parathion (Phosphorothioic acid, O,O-diethyl O-(4-nitrophenyl)
ester)
Pentachlorobenzene (Benzene, pentachloro-)
Pentachlorodibenzo-p-dioxins
Pentachlorodibenzofurans
Pentachloroethane (Ethane, pentachloro-)
Pentachloronitrobenzene (PCNB) (Benzene, pentachloronitro-)
Pentachlorophenol (Phenol, pentachloro-)
Phenacetin (Acetamide, N-(4-ethoxyphenyl)-)
Phenol
Phenylenediamine (Benzenediamine)
Phenylmercury acetate (Mercury, (acetato-O)phenyl-)
[[Page 2871]]
Phenylthiourea (Thiourea, phenyl-)
Phosgene (Carbonic dichloride)
Phosphine
Phorate (Phosphorodithioic acid, O,O-diethyl S-[(ethylthiomethyl]
ester)
Phthalic acid esters, N.O.S.
Phthalic anhydride (1,3-isobenzofurandione)
2-Picoline (Pyridine, 2-methyl-)
Polychlorinated biphenyls, N.O.S.
Potassium cyanide (K(CN))
Potassium silver cyanide (Argentate(l-), bis(cyano-C)-, potassium)
Pronamide (Benzamide, 3,5-dichloro-N-(1,1-dimethyl-2-propynyl)-)
1,3-Propane sultone (1,2-Oxathiolane, 2,2-dioxide)
n-Propylamine (1-Propanamine)
Propargyl alcohol (2-Propyn-1-ol)
Propylene dichloride (Propane, 1,2-
dichloro-)
1,2-Propylenimine (Aziridine, 2-methyl-)
Propylthiouracil (4(1H)-Pyrimidinone, 2,3-dihydro-6-propyl-2-thioxo-
)
Pyridine
Reserpinen (Yohimban-16-carboxylic acid, 11,17-dimethoxy-18-[(3,4,5-
trimethoxybenzoyl)oxy]-smethyl ester, (3,16
,17,18,20)-)
Resorcinol (1,3-Benzenediol)
Saccharin and salts (1,2-Benzisothiazol-3(2H)-one, 1,1-dioxide)
Safrole (1,3-Benzodioxole, 5-(2-propenyl)-)
Selenium and compounds, N.O.S.
Selenium dioxide (Selenious acid)
Selenium sulfide (SeS2)
Selenourea
Silver and compounds, N.O.S.
Silver cyanide (Silver cyanide Ag(CN))
Silvex (Propanoic acid, 2-(2,4,5-trichlorophen
oxy)-)
Sodium cyanide (Sodium cyanide Na(CN))
Streptozotocin (D-Glucose, 2-deoxy-2-
[[methylnitrosoamino)carbonyl]amino]-)
Strychnine and salts (Strychnidin-10-one)
TCDD (Dibenzo[b,e][1,4]dioxin, 2,3,7,8-tetrachloro-)
1,2,4,5-Tetrachlorobenzene (Benzene, 1,2,4,5-tetrachloro-)
Tetrachlorodibenzo-p-dioxins
Tetrachlorodibenxofurans
Tetrachloroethane, N.O.S. (Ethane, tetrachloro-, N.O.S.)
1,1,1,2-Tetrachloroethane (Ethane, 1,1,1,2-tetrachloro-)
1,1,2,2-Tetrachloroethane (Ethane, 1,1,2,2-tetrachloro-)
Tetrachloroethylene (Ethene, tetrachloro-)
2,3,4,6-Tetrachlorophenol (Phenol, 2,3,4,6-tetrachloro-)
Tetraethyldithiopyrophosphate (Thiodiphosphoric acid, tetraethyl
ester)
Tetraethyl lead (Plumbane, tetraethyl-)
Tetraethyl pyrophosphate (Diphosphoric acid, tetraethyl ester)
Tetranitromethane (Methane, tetranitro-)
Thallium and compounds, N.O.S.
Thallic oxide (Thallium oxide Tl2O3)
Thallium (I) acetate (Acetic acid, thallium (1+) salt)
Thallium (I) carbonate (Carbonic acid, dithallium (1+) salt)
Thallium (I) chloride (Thallium chloride TlCl)
Thallium (I) nitrate (Nitric acid, thallium (1+) salt)
Thallium selenite (Selenius acid, dithallium (1+) salt)
Thallium (I) sulfate (Sulfuric acid, thallium (1+) salt)
Thioacetamide (Ethanethioamide)
3,Thiofanox (2-Butanone, 3,3-dimethyl-1-(methylthio)-, O-
[(methylamino)carbonyl] oxime)
Thiomethanol (Methanethiol)
Thiophenol (Benzenethiol)
Thiosemicarbazide (Hydrazinecarbothioamide)
Thiourea
Thiram (Thioperoxydicarbonic diamide [(H2N)C(S)]2S2,
tetramethyl-)
Toluene (Benzene, methyl-)
Toluenediamine (Benzenediamine, ar-methyl-)
Toluene-2,4-diamine (1,3-Benzenediamine, 4-methyl-)
Toluene-2,6-diamine (1,3-Benzenediamine, 2-methyl-)
Toluene-3,4-diamine (1,2-Benzenediamine, 4-methyl-)
Toluene diisocyanate (Benzene, 1,3-diisocyanatomethyl-)
o-Toluidine (Benzenamine, 2-methyl-)
o-Toluidine hydrochloride (Benzenamine, 2-methyl-, hydrochloride)
p-Toluidine (Benzenamine, 4-methyl-)
Toxaphene
1,2,4-Trichlorobenzene (Benzene, 1,2,4-trichloro-)
1,1,2-Trichloroethane (Ethane, 1,1,2-trichloro-)
Trichloroethylene (Ethene,trichloro-)
Trichloromethanethiol (Methanethiol, trichloro-)
Trichloromonofluoromethane (Methane, trichlorofluoro-)
2,4,5-Trichlorophenol (Phenol, 2,4,5-trichloro-)
2,4,6-Trichlorophenol (Phenol, 2,4,6-trichloro-)
2,4,5-T (Acetic acid, 2,4,5- trichloro-
phenoxy-)
Trichloropropane, N.O.S.
1,2,3-Trichloropropane (Propane, 1,2,3-trichloro-)
O,O,O-Triethyl phosphorothioate (Phosphorothioic acid, O,O,O-
triethyl ester)
Trinitrobenzene (Benzene, 1,3,5-trinitro-)
Tris(1-aziridinyl)phosphine sulfide (Aziridine,
1,1',1''phosphinothioylidynetris-))
Tris(2,3-dibromopropyl) phosphate (1-Propanol, 2,3-dibromo-,
phosphate (3:1))
Trypan blue (2,7-Naphthalendisulfonic acid, 3,3'-[(3,3'-
dimethyl[1,1'-biphenyl]-4,4'-diyl)bis(azo)]bis(5-amino-4-hydroxy-,
tetrasodium salt)
Uracil mustard (2,4-(1H,3H)-Pyrimidinedione, 5-[bis(2-
chloroethyl)amino]-)
Vanadium pentoxide (Vanadium oxide V2O5)
Vinyl chloride (Ethene, chloro-)
Wayfarin (2H-1-Benzopyran-2-one, 4-hydroxy-3-(3-oxo-1-phenlybutyl)-)
Zinc cyanide (Zn(CN)2)
Zinc phosphide (Zn3P2)
[FR Doc. 95-546 Filed 1-10-95; 8:45 am]
BILLING CODE 6560-50-P
