[Federal Register Volume 61, Number 89 (Tuesday, May 7, 1996)]
[Rules and Regulations]
[Pages 20686-20694]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-11080]




[[Page 20685]]


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Part IV





Environmental Protection Agency





_______________________________________________________________________



40 CFR Part 131



Water Quality Standards for Surface Waters in Arizona; Final Rule

Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and 
Regulations

[[Page 20686]]



ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 131

[FRL-5467-9]


Water Quality Standards for Surface Waters in Arizona

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: This rule establishes water quality standards applicable to 
waters of the United States in the State of Arizona. EPA is 
promulgating this rule pursuant to a court order in Defenders of 
Wildlife v. Browner (Docket No. Civ. 93-234 TUC ACM). The rule 
designates fish consumption as a use for certain waters, and requires 
implementation of a monitoring program regarding mercury's effects on 
wildlife. On January 29, 1996, EPA published a proposed rule that 
included other provisions which are not being promulgated as part of 
today's rule because, after EPA's proposal, the Arizona Department of 
Environmental Quality adopted revised regulations and policies in those 
areas which EPA Region 9 has determined are in accordance with the 
Clean Water Act.

EFFECTIVE DATE: June 6, 1996.

ADDRESSES: This action's administrative record is available for review 
and copying at the Water Management Division, EPA, Region 9, 75 
Hawthorne St., San Francisco, CA 94105. For access to the docket 
materials, call (415) 744-1978 for an appointment. A reasonable fee 
will be charged for copies.

FOR FURTHER INFORMATION CONTACT: Gary Wolinsky, Permits and Compliance 
Branch, W-5, Water Management Division, EPA, Region 9, 75 Hawthorne 
St., San Francisco, CA 94105, telephone: 415 744-1978.

SUPPLEMENTARY INFORMATION:

A. Regulated Entities

    Entities potentially regulated by this action are those discharging 
pollutants to waters of the United States in Arizona. Regulated 
categories and entities include:

------------------------------------------------------------------------
          Category                  Examples of regulated entities      
------------------------------------------------------------------------
Industry....................  Industries discharging mercury to surface 
                               waters in Arizona, or discharging        
                               pollutants to particular surface waters  
                               in Arizona listed in sec. 131.31(b) of   
                               the rule.                                
Municipalities..............  Publicly-owned treatment works discharging
                               mercury to surface waters in Arizona, or 
                               discharging pollutants to particular     
                               surface waters listed in sec. 131.31(b)  
                               of the rule.                             
------------------------------------------------------------------------

    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities likely to be regulated by this 
action. This table lists the types of entities that EPA is now aware 
could potentially be regulated by this action. Other types of entities 
not listed in the table could also be regulated. To determine whether 
your facility is regulated by this action, you should examine the list 
of waterbodies in section 131.31(b) of this rule, and examine 40 CFR 
131.2 which describes the purpose of water quality standards such as 
those established in this rule. If you have questions regarding the 
applicability of this action to a particular entity, consult the person 
listed in the preceding FOR FURTHER INFORMATION CONTACT section.

B. Background

    Under section 303 (33 U.S.C. 1313) of the Clean Water Act (CWA), 
states are required to develop water quality standards for waters of 
the United States within the state. Section 303(c) provides that a 
water quality standard shall include a designated use or uses to be 
made of the water and criteria necessary to protect those uses. States 
are required to review their water quality standards at least once 
every three years and, if appropriate, revise or adopt new standards. 
33 U.S.C. 1313(c). States are required to submit the results of their 
triennial review of their water quality standards to EPA. EPA is to 
approve or disapprove any new or revised standards. Id.
    States may include in their standards policies generally affecting 
the standards' application and implementation. See 40 CFR 131.13. These 
policies are subject to EPA review and approval. 40 CFR 131.6(f), 40 
CFR 131.13.
    Section 303(c)(4) of the CWA authorizes EPA to promulgate water 
quality standards that supersede disapproved State water quality 
standards, or in any case where the Administrator determines that a new 
or revised water quality standard is needed to meet the CWA's 
requirements.
    In September 1993, EPA, Region 9, disapproved portions of Arizona's 
standards pursuant to section 303(c) of the CWA and 40 CFR 131.21. The 
portions of Arizona's standards disapproved in September 1993 relate 
to: the exclusion of mining-related impoundments from water quality 
standards; the absence of ``fish consumption'' as a designated use for 
certain water bodies; the absence of implementation procedures for the 
State's narrative nutrient standard; the absence of biomonitoring 
implementation procedures for the State's narrative toxicity criterion; 
and the inclusion of practical quantitation limits (PQLs) in Arizona's 
standards. In April 1994, EPA, Region 9, also disapproved Arizona's 
lack of water quality criteria protective of wildlife for mercury.
    On November 1, 1995, the United States District Court for the 
District of Arizona ordered EPA to prepare and publish proposed 
regulations setting forth revised or new water quality standards for 
those standards disapproved in September 1993 and April 1994 within 90 
days. Defenders of Wildlife v. Browner, Docket No. Civ 93-234 TUC ACM.
    On December 29, 1995, the Arizona Department of Environmental 
Quality (ADEQ) published proposed revisions to its standards. 1 Ariz. 
Admin. Reg. 2811.
    Consistent with the Court's order, on January 29, 1996, EPA 
published a Federal Register notice proposing standards related to the 
mining exclusion, fish consumption designated use, PQLs, and 
implementation policies and procedures. 61 FR 2766. The notice also 
identified, and sought comment on, policies that EPA, Region 9, 
intended to use to implement State narrative criteria as they relate to 
toxicity, nutrients, and mercury.
    The Court order in Defenders of Wildlife directs EPA to promulgate 
final water quality standards 90 days after EPA proposes such standards 
unless Arizona has adopted revised or new water quality standards which 
EPA determines are in accordance with the CWA. In January 1996, ADEQ 
adopted implementation procedures for the State's narrative nutrient 
criteria. In April 1996, ADEQ adopted implementation procedures for the 
State's narrative toxic criteria. On April 26, 1996, EPA, Region 9, 
approved Arizona's implementation procedures for the State's narrative 
nutrient and toxic criteria. Because EPA has

[[Page 20687]]

determined that Arizona has addressed EPA's 1993 disapproval action 
regarding the absence of appropriate implementation procedures for 
toxicity and nutrients through the adoption of procedures that are in 
accordance with the Act, EPA is not promulgating provisions in the 
final rule related to these implementation procedures.
    ADEQ adopted revisions to its standards on March 22, 1996, and, 
after obtaining the approval of the State's Regulatory Review Council, 
filed revisions to its standards with Arizona's Secretary of State on 
April 24, 1996. ADEQ's rulemaking repealed the mining related provision 
(R18-11-103.2) disapproved by EPA, Region 9, in September 1993, and 
established a revised exemption related to mining impoundments at R18-
11-102. In addition, ADEQ's rulemaking added the fish consumption use 
to most of the waters which would have been designated with the fish 
consumption use under EPA's proposal. The State's rulemaking also 
deleted the appendix which prescribed PQLs from the State's water 
quality standards regulations. On April 26, 1996, EPA, Region 9 
approved these revised regulations thereby removing the need to 
promulgate a Federal regulation addressing these issues.
    ADEQ has also participated, with EPA, Region 9, and the U.S. Fish 
and Wildlife Service, in the development of an interim approach to 
protect predatory wildlife from mercury until appropriate numeric 
criteria can be developed. In conjunction with Arizona's priority 
pollutant program, ADEQ, in cooperation with the Arizona Game and Fish 
Department, the U.S. Fish and Wildlife Service, and EPA will conduct a 
tissue monitoring program to assess the magnitude and extent of mercury 
bioaccumulation in the prey base of the bald eagle and other fish-
eating birds in Arizona. The monitoring program identifies further 
actions related to sampling, source identification and remedy selection 
which the agencies will undertake if mercury levels in fish are found 
above a specified action level. Because pursuit of this monitoring 
program is an important component in addressing the problem of mercury 
contamination in Arizona waters, EPA has included the proposed 
regulatory provision related to mercury in the final rule. In addition, 
EPA is promulgating the fish consumption use designation for 
waterbodies identified in EPA's proposal for which the State did not 
adopt the fish consumption use designation. As explained more fully 
below, should EPA decide to approve ``use attainability analyses'' 
recently submitted by Arizona, EPA will proceed expeditiously to 
withdraw the revised use designations contained in today's rule.

C. Summary of Final Rule and Response to Major Comments

    A description of EPA's final action, and a summary of major 
comments regarding the proposal and EPA's response, are set forth 
below. Additional comments and responses to comments are in the 
administrative record.

1. ``Fish Consumption'' Use

    Arizona has designated several uses for its waters, including uses 
defined as ``fish consumption'', ``aquatic and wildlife (cold water 
fishery)'', ``aquatic and wildlife (effluent dominated water)'', 
``aquatic and wildlife (ephemeral)'', and ``aquatic and wildlife (warm 
water fishery)''. See, R-18-11-101, and Appendix B of Title 18, Chapter 
11, Article 1, of Arizona Administrative Rules and Regulations.
    In September 1993, EPA disapproved the lack of the ``fish 
consumption'' (FC) use for water bodies which Arizona designated as 
having an ``aquatic and wildlife'' use. For the standards to be 
approvable, EPA stated that the State must either revise its standards 
to include the FC use, or submit ``use attainability analyses'' (UAAs), 
for the subject waters. A UAA is a scientific assessment showing 
whether it is feasible to attain a particular use. See, 40 CFR 131.3(g) 
and 131.10(j).
    ADEQ subsequently completed UAAs showing that it need not designate 
the FC use for those effluent dominated or ephemeral waters which it 
had not already designated as having the FC use. EPA approved those 
UAAs in November 1995.
    In December 1995, ADEQ proposed to revise its standards to add the 
FC use to waters within the State which have the ``aquatic and wildlife 
(cold water fishery)'' or ``aquatic and wildlife (warm water fishery)'' 
use. See, 1 Ariz. Admin. Reg. 2811 (Dec. 29, 1995), proposed R-18-11-
104 and Appendix B of Title 18, Chapter 11, Article 1, of Arizona 
Administrative Rules and Regulations.
    In January 1996, EPA proposed to designate the fish consumption use 
for those waters which Arizona had designated as having an ``aquatic 
and wildlife'' use, in those cases where the requirements for 
completing a UAA had not been met. The affected stream segments and 
water bodies were listed in proposed section 131.31(c). Each of the 
affected waters were, at the time of EPA's proposal, designated by 
Arizona as having the ``aquatic and wildlife (cold water fishery)'' or 
``aquatic and wildlife (warm water fishery)'' use.
    With the exception of fifteen waterbodies, Arizona's April 1996 
final rulemaking established the FC use for all the waterbodies subject 
to EPA's proposal.
    EPA is not promulgating a Federal rule designating the FC use for 
those waters which now have that designated use under Arizona's rules. 
In addition, EPA is not promulgating a Federal rule designating the FC 
use for Quarter Circle Bar Tank. EPA has determined that that waterbody 
is located within the boundaries of the Navajo Reservation and this 
rulemaking only applies to waters within the jurisdiction of the State 
of Arizona. The spelling of two waterbodies has been corrected in the 
final rule.
    On April 3 and April 10, 1996, ADEQ submitted UAAs in support of 
its determination not to designate the FC use for eleven of the 
fourteen State waterbodies listed in EPA's proposal which did not 
receive the FC use designation under Arizona's April 1996 rulemaking. 
EPA is currently reviewing the analyses provided by the State. In 
accordance with Region 9 practice in this area, the Region has also 
sent out the new analyses for public review and comment to persons and 
organizations with interests related to water quality standards 
determinations in Arizona. EPA has asked for comments by May 15, 1996. 
ADEQ intends to submit a UAA in support of its determination not to 
designate the FC use for the three remaining waterbodies (Davidson 
Canyon and Tinaja Wash in the Santa Cruz River Basin, and Chase Creek 
in the Upper Gila River Basin) listed in EPA's proposed rule. EPA, 
Region 9, will send out that UAA for public review and comment.
    Because EPA is under court order to promulgate this regulation by 
the end of April, and the State submitted UAAs with insufficient time 
for the Agency to adequately review the documentation and solicit 
public comment prior to its court-ordered deadline, EPA is promulgating 
the fish consumption use designation for waterbodies identified in 
EPA's proposal which do not now have the FC designated use. Should EPA 
approve, after completing its review of the UAAs and public comments, 
the State's determination that attaining the FC use is not feasible 
with respect to a waterbody listed in today's rule, EPA will proceed 
expeditiously to withdraw the revised use designation contained in 
section 131.31(c) with respect to that waterbody. If EPA approves the 
State's UAA prior to the effective date of this rule with respect to a 
waterbody listed

[[Page 20688]]

in section 131.31(c), EPA intends to stay the effectiveness of the 
Federal use designation with respect to that waterbody pending 
withdrawal of that part of the rule by EPA.
    EPA received a number of comments opposing provisions of the 
proposed rule relating to fish consumption. One commenter submitted 
extensive comments objecting to EPA's proposal to promulgate the FC 
designated use, particularly with respect to the segment of the Salt 
River from the I-10 bridge to the 23rd Avenue WWTP discharge. The 
commenter contended that EPA should not have disapproved the lack of 
the FC use on waters designated by Arizona as having the aquatic and 
wildlife (warm water fishery) use. The commenter stated that EPA's 
disapproval did not explain how the Arizona standards were inconsistent 
with section 101(a)(2) of the Act, that EPA's reliance upon 40 CFR 
131.10(j)(1) in its disapproval was inappropriate, and that a UAA was 
not required in order to avoid designating the FC use for the subject 
waters. The commenter stated that EPA rules and guidance documents do 
not require a FC designated use if other water quality standards are 
sufficient to protect the health of persons who may consume harvested 
aquatic life, and that the Act does not require a specific FC use for 
any waters at all. This commenter further stated that EPA has generated 
no evidence to support its hypothesis that the aquatic and wildlife 
(warm water fishery) designated use is not sufficient for the minimal 
harvesting of edible aquatic life that could potentially occur on the 
Salt River segment between the I-10 Bridge and the 23rd Avenue 
wastewater treatment plant. The commenter stated that Arizona's use 
designations and criteria, taken as a whole, are entirely 
``consistent'' with the goals of the CWA, and that consistency is all 
that is required in light of 40 CFR 131.5 and 131.6. The commenter 
stated that the CWA and Arizona law require protection of only those 
uses that are actually occurring or are reasonably foreseeable, and 
that EPA erroneously assumed in this case that the Act requires the FC 
use found in the Arizona water quality standards to apply to all river 
segments regardless of local environmental conditions, the degree and 
types of harvesting by humans, and the types of aquatic life in the 
riverbed.
    EPA continues to believe that EPA Region 9's disapproval of the 
absence of fish consumption use designations for certain waterbodies 
was consistent with the requirements of the CWA. EPA regulations 
regarding use designations provide that a State ``must conduct a use 
attainability analysis as described in 40 CFR 131.3(g) whenever the 
State designates or has designated uses that do not include the uses 
specified in section 101(a)(2) of the Act.'' 40 CFR 131.10(j)(1). 
Section 101(a)(2) of the CWA provides that water quality ``shall 
provide for the protection of fish, shellfish, wildlife and recreation 
in and on the water'', and, in EPA's view, the ``protection'' of fish, 
shellfish, and recreation necessarily includes ensuring that fish are 
not so contaminated that they are unhealthful for human consumption. 
Nonetheless, the State had failed to include designated uses that would 
protect such aquatic life for purposes of human consumption, or to 
perform a UAA demonstrating that this use was not attainable. EPA, 
Region 9, therefore appropriately concluded that the State's standards 
were not ``consistent with'' the goals of the CWA. Finally, while this 
commenter asserts that a FC designated use is not necessary if other 
standards are sufficient to protect the health of persons, the State 
has not contended that it has adopted criteria applicable to these 
waters that would protect human health. The State's existing water 
quality criteria were derived to protect aquatic life itself, not 
humans who consume it. Unlike aquatic life criteria, human health 
criteria take into account many factors that must be considered to 
ensure that pollutant residues in fish, when consumed by humans, do not 
result in adverse health effects. See generally 40 CFR Part 132, 
Appendices A and C, 60 FR 15393-15411 (March 23, 1995) (containing 
methodologies for deriving aquatic life and human health criteria for 
the Great Lakes Basin). EPA therefore believes that there is not a 
reasonable basis to conclude that the State's aquatic life criteria 
will provide protection for persons consuming fish from these specified 
waterbodies.
    This commenter apparently also would seek to place the burden on 
EPA Regions to demonstrate that existing uses and criteria are not 
adequate to protect human health, taking into account local 
environmental conditions and consumption patterns, prior to 
disapproving state standards that fail to include the uses reflected in 
section 101(a)(2) of the Act. This position ignores the fact that, 
under EPA regulations, a UAA is the appropriate mechanism by which 
States can determine whether local environmental conditions and other 
factors justify the absence of a use otherwise meriting protection 
under the Act. Turning this process on its head and requiring EPA, 
which has far less familiarity with local circumstances and conditions 
than does the State agency, to make these determinations would be 
impracticable and would significantly undermine the health protection 
goals of the Act. Finally, the issue in Arizona was not whether the 
State had reasonably concluded that existing standards for these 
waterbodies would protect human health. Rather, it was the State's 
failure to adopt standards protecting human health that precipitated 
the Region's disapproval action.
    One commenter stated that, even if an additional use designation 
were necessary and supported by an administrative record, EPA has 
failed to promulgate scientifically supportable, reasonable and 
necessary numeric criteria to protect the use. The commenter stated 
that the CWA requires numeric criteria only for those toxic pollutants 
for which criteria have been published under section 304(a) of the CWA, 
the discharge or presence of which in the affected waters could 
reasonably be expected to interfere with those designated uses adopted 
by the State, as necessary to support such designated uses, and that 
EPA has not conducted the analysis required by this section to 
determine what numeric criteria would be appropriate to support the new 
FC use on the affected surface waters. The commenter stated that there 
is no administrative record to support EPA's FC use and associated 
numeric criteria for all surface waters, and that EPA should have 
considered whether any of the surface waters potentially subject to the 
new FC use would be entitled to a modification of the use on the basis 
of the factors in 40 CFR 131.10(g). The commenter also stated that the 
social and economic impact of the FC designations would be severe in 
Phoenix, noting that some of the Phoenix storm water outfalls discharge 
into the Salt River segment that would be reclassified under the 
proposed rule. The commenter stated that the proposed rule could have a 
substantial impact on storm water discharges and substantially increase 
costs to the public without any demonstrated improvement in public 
health. The commenter further stated that the upgrading of the Salt 
River and other segments with the FC use could also have a ripple 
effect that would result in more costly standards for upstream 
ephemeral segments, noting that Arizona water quality standards appear 
to require that designated uses for upstream segments shall not cause a 
violation of water quality standards in downstream segments, and that 
economic impact of the proposed FC use could spread

[[Page 20689]]

upstream to ephemeral waters that clearly do not warrant the FC use.
    The comments regarding the appropriateness of criteria that will 
now apply to these waterbodies appear to indicate that commenters have 
misunderstood EPA's action. The State has itself adopted criteria that 
it believes are appropriate for providing protection of persons 
consuming fish from many State waters. EPA is not second-guessing this 
determination by the State. EPA also disagrees that it was under a duty 
to evaluate the attainability of the fish consumption use taking into 
account the factors in 40 CFR 131.10(g). Again, under EPA regulations, 
States have the opportunity and responsibility for conducting UAAs to 
demonstrate that uses consistent with the goals of the CWA are not 
attainable. The State had failed to do so here. EPA therefore was 
within its authority to determine that the use designations needed to 
be revised to be consistent with the goals in CWA section 101(a)(2). 
The State remains free to determine, based on local environmental 
conditions or the costs that it determines could be associated with the 
revised use designations, to downgrade use designations in accordance 
with 40 CFR 131.10(g). No commenters provided information during the 
public comment period indicating that, in fact, the revised use 
designations were not attainable according to the criteria contained in 
section 131.10(g).
    Another commenter also questioned whether the segment of the Salt 
River from the I-10 bridge to the 23rd Avenue WWTP discharge should be 
designated as having the fish consumption use. The commenter stated 
that, if EPA's rationale for promulgating the fish consumption use is 
simply because the stream segment had been designated by Arizona as 
having the ``aquatic and wildlife (warm water fishery)'' use, then the 
process and rationale for designating the segment is suspect and should 
be reviewed.
    Another commenter stated that the fish consumption designated use 
should not be presumptively applied to all water bodies, and should be 
applied only when it is shown that fishing is a legal, continuous, and 
widespread use of a particular water body. The commenter objected to 
allowing the addition of designated uses to a stream segment without 
the requirement to make any particular showing while the removal of a 
use may take place only after a comprehensive use attainability 
analysis which is often beyond the financial or technical capability of 
the individuals most directly affected by the inappropriately 
designated use.
    Another commenter sought clarification that EPA's designation of 
the fish consumption use would be limited to water bodies which are 
waters of the United States.
    As explained previously, EPA believes that it was appropriate and 
consistent with the requirements and goals of the CWA to promulgate 
fish consumption use designations where the State has designated the 
waters as supporting aquatic life. EPA disagrees that the CWA places a 
burden on EPA or States to demonstrate legal, widespread and continuous 
use of a waterbody before adopting a FC use designation. No such 
restriction is evident in the language or legislative history of the 
CWA. To support a particular use designation, it is sufficient that 
such a use be attainable in the waterbody. Regarding the use 
designation for the Salt River from the I-10 bridge to the 23rd Avenue 
WWTP discharge, that segment is not addressed by today's rule since the 
State adopted the FC use for this waterbody. See, R-18-11-101, and 
Appendix B of Title 18, Chapter 11, Article 1, of Arizona 
Administrative Rules and Regulations, as filed on April 24, 1996.
    The one commenter is correct that the revised use designations only 
apply to waters that meet the definition of waters of the United 
States.

2. Water Quality Criteria Protective of Wildlife for Mercury

    Arizona has established numeric criteria for mercury for ``aquatic 
and wildlife'', ``fish consumption'', ``domestic water source'' and 
other uses designated for its waters. See, Appendix A of Title 18, 
Chapter 11, Article 1, of Arizona Administrative Rules and Regulations. 
As part of its consultation with EPA regarding Arizona's water quality 
standards pursuant to section 7 of the Endangered Species Act, the U.S 
Fish and Wildlife Service (FWS) determined that Arizona's mercury 
criteria for protection of aquatic and wildlife uses were developed 
without consideration of bioaccumulative effects for predatory 
wildlife, and the FWS identified the adoption of mercury criteria 
protective of wildlife as a means to remove jeopardy to endangered and 
threatened species in the context of the Endangered Species Act.
    Based upon FWS's determinations, EPA, Region 9, in April 1994 
disapproved Arizona's lack of water quality criteria protective of 
wildlife for mercury.
    While the FWS identified the adoption of a mercury criterion 
protective of wildlife as a reasonable and prudent alternative to avoid 
jeopardizing endangered and threatened wildlife species, further 
discussions between EPA, ADEQ, Arizona Game and Fish Department, and 
the FWS led to the development of an alternative program to address the 
problem of mercury's impacts on endangered and threatened species. The 
Service indicated its overall approval of this approach to dealing with 
the problem of mercury as it relates to the protection of wildlife and, 
on January 17, 1996, revised its determination which initially 
identified adoption of a mercury criterion as a reasonable and prudent 
alternative for removing jeopardy to endangered species. Accordingly, 
in January 1996, EPA proposed section 131.31(f) to address the 
deficiency in the State's standards related to mercury's effect on 
wildlife, and solicited comment upon EPA's intent to implement a 
monitoring and source identification program to assist EPA in 
implementing Arizona's narrative toxicity criteria.
    ADEQ has continued to participate, with EPA, Region 9, and the U.S. 
Fish and Wildlife Service, in the development of an interim program to 
protect predatory wildlife from mercury until appropriate numeric 
criteria can be developed. The program developed by the agencies is 
described in ``Arizona Priority Pollutant Sampling Program, ADEQ/AGFD/
USFWS/USEPA Cooperative Program'', March 29, 1996. Under that program, 
ADEQ, in cooperation with the Arizona Game and Fish Department, the 
U.S. Fish and Wildlife Service, and EPA will conduct a tissue 
monitoring program to assess the magnitude and extent of mercury 
bioaccumulation in the prey base of the bald eagle and other fish-
eating birds in Arizona. This monitoring program identifies further 
actions related to sampling, source identification, and remedy 
selection which the agencies will undertake if mercury levels in fish 
are found above a specified action level.
    EPA received comment upon its proposal to adopt section 131.31(f) 
and upon the monitoring and source identification program identified in 
the Federal Register notice. A commenter stated that, even with the 
implementation procedures proposed by EPA, Arizona's narrative toxicity 
criteria would not protect against food chain accumulation in birds and 
other fish-eating species. The commenter contended that there was no 
deadline for completion of the monitoring and stated that there is no 
need to wait for further fish tissue monitoring because recent tests in 
certain lakes have found mercury levels exceeding the 0.1 mg/kg level 
identified under the proposed

[[Page 20690]]

monitoring program as the trigger for further control efforts. The 
commenter also noted that a mercury criterion to protect against food 
chain accumulation has been established for the Great Lakes, and that a 
similar criterion could be developed for Arizona. The commenter stated 
that the Arizona criterion might differ if there were evidence that 
mercury uptake rates among Arizona fishes are markedly different than 
among Great Lakes fishes, but that EPA has offered no evidence to 
suggest this is so.
    EPA's long-term goal is the adoption of a mercury criterion for 
wildlife. However, despite the claims by the commenter, the data 
currently are not available to derive a mercury criterion for wildlife 
in Arizona using the methodology developed for the Great Lakes. A 
detailed discussion of the data needed to develop a criterion is 
discussed below. In lieu of a numeric criterion, EPA believes that the 
approach of using Arizona's narrative criterion in R18-11-108 for 
toxicity in combination with the implementation of the tissue 
monitoring program will satisfy the requirements of the CWA to provide 
protection of designated uses, including wildlife protection and 
propagation.
    With regard to the commenter's general point regarding the 
necessity of having numeric criteria in order to meet the requirements 
of the CWA, it should be emphasized that the absence of a numeric 
criterion for a specific pollutant is not unusual. EPA has not 
published criteria guidance for the protection of aquatic life for all 
pollutants. To account for this unavoidable absence of numeric criteria 
for all pollutants, States include narrative criteria as part of their 
standards. Narrative criteria are intended to cover all pollutants and 
endpoints for which the state has not adopted numeric criteria. The 
role of narrative criteria in the CWA's regulatory program is evident 
in EPA's permitting regulations which include explicit provisions 
requiring permit limits to ensure narrative criteria are not exceeded. 
40 CFR 122.44(d)(1)(vi).
    In addition, the commenter was concerned that there was no deadline 
for completion of the tissue monitoring program. However, sampling will 
commence in the spring of 1996 and continue through the year 2000. The 
FWS biological opinion, and the FWS's revised determination regarding 
reasonable and prudent alternatives, are included in the administrative 
record for this rulemaking.
    The purpose of the tissue monitoring program is to provide 
information that can be used to assist in evaluating the magnitude of 
mercury contamination of wildlife in Arizona. The monitoring program 
was developed in consultation with the FWS, ADEQ, and Arizona Game and 
Fish Department. EPA believes the sampling program is a reasonable 
first step for identifying those areas in the State where problems may 
exist and for designing control strategies that will help remediate 
such problems to benefit wildlife protection in Arizona. The program 
will assist EPA in determining whether contaminated fish species are 
isolated cases due to particular sources of pollution (in which case 
development of permit limits for a particular discharger based on the 
State's existing narrative criterion may be the best means of remedying 
the problem) or whether they are indicative of a larger State-wide 
problem which needs to be addressed (potentially based on state-wide 
numeric criteria, when development of such criteria are technically 
feasible). If during the tissue monitoring it is determined that the 
mercury tissue levels are consistently found above the action level of 
0.1 mg/kg in the prey base of bald eagle or Yuma clapper rail, then 
steps will be taken to identify the sources of the contamination and 
identify possible corrective measures.
    EPA is concerned with the elevated mercury levels at the 
waterbodies identified by the commenter. While neither of the two lakes 
specifically cited by the commenter were identified by FWS as priority 
water bodies for sampling for mercury for threatened and endangered 
species, EPA is seeking to identify the sources contributing to the 
mercury levels detected in the two lakes and corrective measures for 
them.
    The commenter is correct that a methodology for deriving wildlife 
criteria and a mercury criterion for wildlife were recently established 
in the Great Lakes Water Quality Initiative (``GLI''). It is important 
to note that the GLI wildlife methodology and criteria were developed 
over several years with input from two national conferences and several 
consultations with EPA's Science Advisory Board along with over 5000 
public comments on the proposed GLI. In addition to the large effort 
undertaken to develop the methodology and criteria, EPA stated very 
clearly in the Supplementary Information Document to the GLI that:

    EPA would like to reemphasize that the provisions in the 
proposed and final Guidance are expressly applicable only to the 
waters of the Great Lakes System * * * States or Tribes with waters 
outside the Great Lakes Systems, in whole or in part, are encouraged 
to implement any of the Guidance methodologies or procedures that 
are scientifically and technically appropriate for their situations. 
Supplementary Information Document, p. 82.

    EPA believes the methodology used in the GLI for deriving a mercury 
wildlife criteria may be appropriate for use in Arizona with some 
modifications based on the specific conditions in Arizona. This does 
not mean, however, that a criterion can simply be developed using the 
data from the Great Lakes. In addition, the commenter implies that the 
only question which needs to be considered when applying the GLI 
methodology is whether the mercury uptake rates among Arizona fishes 
are markedly different than among Great Lakes fishes. In fact, the 
bioaccumulation potential is only one component that goes into the 
derivation of wildlife criteria.
    ADEQ reviewed the GLI methodology for deriving wildlife criteria to 
evaluate its applicability to Arizona and submitted their comments to 
EPA on May 12, 1995, which are part of the administrative record. EPA 
agrees with ADEQ that ecological conditions differ in Arizona from the 
Great Lakes region. Therefore direct application of the GLI methodology 
without modification is probably not appropriate. Development of a 
wildlife criterion to protect wildlife from mercury in Arizona will 
likely require the completion of tasks analogous to those undertaken by 
EPA in the GLI. This effort is necessary because several components 
within the wildlife methodology are specific to the type of aquatic 
ecosystem and associated wildlife species. It would not be 
scientifically defensible to directly adopt the mercury wildlife 
criterion for the Great Lakes in the regulation of Arizona ecosystems 
without further analyses to support such a decision. Issues that will 
require further data evaluation and analyses include: (1) The 
establishment of representative wildlife species for aquatic ecosystems 
in Arizona, including a determination of their water and food intake 
rates and the prey that comprises their diets; (2) a determination of 
appropriate mercury toxicity thresholds for the representative wildlife 
species identified for Arizona ecosystems; and (3) the establishment of 
mercury bioaccumulation factors appropriate for Arizona ecosystems and 
their associated food chains.
    The technical analyses needed to establish the representative 
species (and their associated attributes) and appropriate mercury 
bioaccumulation factors will likely require the largest effort because 
these items are most closely associated with the site-specific nature 
of wildlife criteria. In addition to

[[Page 20691]]

the data evaluation and analyses, peer review would be appropriate for 
any wildlife methodology and associated criteria developed in Arizona 
given the numerous technical and scientific issues involved in 
developing such a methodology.
    In summary, while EPA believes the development of a wildlife 
criterion for mercury may be possible, with some modifications, using 
the methodology developed in the GLI, the data to support the 
development of such a criterion are not currently available. Therefore, 
until this information is collected, EPA believes the approach of 
relying on the narrative criterion combined with the tissue monitoring 
program will provide protection of wildlife in a manner consistent with 
the requirements of the Endangered Species Act and Clean Water Act.
    EPA is continuing to evaluate the comments upon the substance of 
the monitoring program, for the purpose of determining whether 
modifications to the program are warranted.
    Another commenter indicated that EPA's disapproval of Arizona's 
lack of water quality criteria protective of wildlife for mercury 
should have been limited to the need for a mercury criterion applicable 
to only those surface waters where affected endangered species are 
likely to be adversely impacted.
    EPA's disapproval action was based upon the biological opinion 
issued by the FWS, which found that the State's existing criteria for 
mercury failed to consider the effects of bioaccumulation of pollutants 
on wildlife. Because bioaccumulative effects may extend beyond 
threatened and endangered species to other species of wildlife, EPA's 
disapproval appropriately extended to Arizona's waters generally.

D. Summary of Provisions in Proposal Not Included in Final Rule

1. Mining Exclusion

    In September 1993, EPA, Region 9, disapproved the exclusion related 
to mining contained in the State's standards at Arizona Administrative 
Rules and Regulations, R18-11-103.2. That exclusion provided that 
Arizona's standards did not apply to certain impoundments and 
associated ditches and conveyances used in the extraction, 
beneficiation and processing of metallic ores.
    In EPA's January 1996 Federal Register notice of proposed 
rulemaking, EPA sought comment on a proposed Federal rule that would 
adopt standards for any waters of the United States not governed by 
State standards due to R18-11-103.2, as that State rule then existed. 
In the preamble to the proposed Federal rule, EPA also solicited 
comment regarding revisions to R18-11-102 that the State had proposed 
in December 1995 regarding the applicability of its standards to 
impoundments and associated ditches and conveyances used in the 
extraction, beneficiation and processing of metallic ores.
    In April 1996 Arizona repealed R18-11-103 in its entirety and 
revised R18-11-102 by, among other things, adding provisions related to 
the applicability of the State's standards to mining-related 
impoundments. R18-11-102 as promulgated differs in certain respects 
from the proposed revision upon which EPA sought comment in its January 
1996 Federal Register notice.
    EPA has determined that Arizona's repeal of R18-11 103.2, and 
Arizona's adoption of revisions to R18-11-102 regarding the 
applicability of the State's standards to certain impoundments and 
associated ditches and conveyances, are consistent with the CWA, and 
that a Federal rule with respect to such impoundments and associated 
ditches and conveyances is not therefore needed to meet the CWA's 
requirements. EPA believes that the State's revision to R18-11-103.2 
adequately addresses EPA's concerns because it excludes from standards 
only those waters that are not waters of the United States. 
Accordingly, EPA is not promulgating the provision which it proposed 
regarding mining-related impoundments, and comments opposing the 
adoption of the proposed Federal rule are moot.
    Other commenters objected to mining-related exclusions under 
consideration in Arizona's rulemaking or encouraged adoption of a 
Federal rule in order to clarify the applicability of water quality 
standards to mining-related activities. One commenter supported the 
application of water quality standards to surface water bodies that 
have been converted into mining impoundments. The commenter also 
indicated that EPA's rule should address the extent to which water 
quality standards are applicable in cases involving stream diversions 
and the placement of mining wastes in dammed creek beds or valleys. The 
commenter indicated its support for broadening the protections 
associated with water quality standards to cover impoundments built in 
the drainages of diverted water bodies. Another commenter suggested 
that uncertainty would be created if Arizona adopted the mining-related 
revisions then under consideration. The commenter noted that it would 
be difficult for persons to determine whether the particular conditions 
for exempting water bodies under Arizona's proposal had been met. The 
commenter suggested that accuracy and simplicity might be better served 
by deleting the State's mining impoundment exemption. EPA considered 
these comments prior to determining that Arizona's final rulemaking 
with respect to mining impoundments is consistent with the CWA and that 
a Federal rule is unneeded.
    Under section 303 of the CWA, States must adopt standards for all 
waters of the United States within the State. See, Kentucky v. Train, 9 
ERC 1280, 1281 (E.D. Ky. 1976). States, however, need not adopt 
standards for any water body which is not a water of the United States. 
EPA has defined waters of the United States to include, among other 
waters, rivers and streams the use, degradation, or destruction of 
which would affect or could affect interstate commerce; impoundments of 
such waters are also waters of the United States. See, 40 CFR 122.2 and 
40 CFR 230.3(s). Accordingly, EPA's disapproval was based on the 
premise that Arizona must adopt standards governing mining impoundments 
which are waters of the United States. In the view of EPA, Region 9, 
the State's revised mining language accords with the CWA because only 
impoundments that are not waters of the United States will not be 
subject to standards. EPA agrees that additional guidance addressing 
the extent to which water quality standards are applicable in cases 
noted by the commenters is desirable.

2. Practical Quantitation Limits

    At the time of EPA's actions disapproving portions of Arizona's 
water quality standards, Arizona had prescribed practical quantitation 
limits (PQLs) in the regulations establishing its water quality 
standards. See, R18-11-120, and Appendix C of Title 18, Chapter 11, 
Article 1, of Arizona Administrative Rules and Regulations (1992). 
Under Arizona's regulations, ``practical quantitation limit means the 
lowest level of quantitative measurement that can be reliably achieved 
during routine laboratory operations.'' R18-11-101.37. In September 
1993, EPA, Region 9, disapproved Arizona's inclusion of the PQLs in its 
regulations. EPA, Region 9, stated that, in order for the standards to 
be approvable under CWA section 303(c), they must protect the 
designated uses and must not be compromised by constraints related to 
analytical methods. EPA, Region 9, further stated that Arizona may 
choose to include the

[[Page 20692]]

PQLs in a policy or guidance document separate from the standards 
regulations.
    In December 1995, ADEQ proposed deleting the PQLs prescribed in 
Appendix C from its regulations and adopting the PQLs in a guidance 
document. See, 1 Ariz. Admin. Reg. 2811 (Dec. 29, 1995), proposed R18-
11-120.
    In its January 1996 action, EPA proposed to adopt a Federal rule 
that would provide that Appendix C of Arizona's regulations would not 
be water quality standards for the purposes of the CWA.
    In its April 1996 rulemaking, Arizona deleted Appendix C from its 
regulations. Accordingly, EPA is not promulgating a rule addressing 
this issue.

3. Implementation Policies

    In September 1993, EPA disapproved the lack of implementation 
procedures for Arizona's narrative nutrient criteria. Arizona's 
narrative nutrient criteria provides that navigable waters shall be 
free from pollutants in amounts or combinations that cause the growth 
of algae or aquatic plants that inhibit or prohibit the habitation, 
growth or propagation of other aquatic life or that impair recreational 
uses. See, R18-11-108.A.6. At the time of the disapproval, Arizona had 
not adopted an implementation process for its narrative criteria.
    Also in September 1993, EPA, Region 9, disapproved the lack of 
implementation procedures for Arizona's narrative toxicity criterion. 
Arizona's narrative toxicity criterion provides that navigable waters 
shall be free from pollutants in amounts or combinations that are toxic 
to humans, animals, plants and other organisms. See, R18-11-108.A.5. At 
the time of the disapproval, Arizona had not adopted implementation 
procedures for toxicity.
    In its January 1996 proposal, EPA proposed to adopt a Federal rule 
to address these deficiencies in the State's standards. Proposed 40 CFR 
131.31(e). In its January 1996 proposal, EPA also solicited comment 
regarding the Region's use of two policies to guide the Region's 
implementation of the subject narrative criteria: ``EPA, Region 9, 
Policy for the Implementation of Arizona's Narrative Nutrient 
Criteria'' and ``EPA, Region 9, Policy on Using Biomonitoring to 
Implement Arizona's Narrative Toxicity Criterion''. As noted in EPA's 
January 1996 Federal Register notice, EPA does not believe that it is 
necessary that the State itself adopt regulatory provisions addressing 
these implementation issues. EPA explained in the Federal Register 
notice that such policies and procedures may be contained either in 
water quality standards regulations themselves, or may be included in a 
standards submission as policy or guidance documents. EPA also stated 
in its January 1996 preamble that, should the State adopt acceptable 
policies and procedures prior to promulgation of a final rule by EPA, 
the Agency would not include the subject regulatory provisions in the 
final rule.
    In January 1996, Arizona adopted a policy for the implementation of 
the State's narrative criteria for nutrients. ADEQ, Water Quality 
Assessment Unit, ``Implementation Guidelines for the Narrative Nutrient 
Standard''. In April 1996, Arizona adopted a policy for the 
implementation of the State's narrative criteria for toxicity. ADEQ, 
``Interim Whole Effluent Toxicity Implementation Guidelines for 
Arizona''.
    After reviewing the State-adopted implementation policies and the 
comments received in response to the January 1996 Federal Register 
notice, EPA, Region 9, approved the policies adopted by the State. With 
respect to EPA's prior disapproval of Arizona's standards due to the 
lack of implementation policies related to narrative criteria for 
nutrients and toxicity, EPA has determined that Arizona's water quality 
standards, as supplemented by the State's newly adopted implementation 
plans, are consistent with the CWA and that no new Federal water 
quality standard is necessary to meet the CWA's requirements. 
Accordingly, EPA is not promulgating proposed 40 CFR 131.31(e).
    EPA received comments regarding its implementation policies in 
response to the January 1996 Federal Register notice. Because EPA has 
approved Arizona's implementation policies, and therefore not 
promulgated a final rule related to these policies, those comments are 
no longer relevant to this rulemaking action. However, those comments 
regarding EPA's policies that are material to EPA's decision to approve 
Arizona's policies have been considered by the Agency in its approval 
action and responses to those comments have been prepared and are part 
of the record supporting EPA's approval of Arizona's narrative toxicity 
and narrative nutrient standards implementation policies. A number of 
comments having to do with the appropriateness of adopting Federal 
implementation policies, or the necessity of having State policies, are 
moot since the State has now adopted its own implementation policies. 
Other comments received were specific to EPA's own toxicity policy for 
Arizona (``EPA, Region 9, Policy on Using Biomonitoring to Implement 
Arizona's Narrative Toxicity Criterion''). These comments addressed the 
purpose and function of toxicity requirements in permits. Since 
Arizona's toxicity policy does not address how the narrative toxicity 
standard will be implemented in permits, these comments have not been 
responded to in EPA's action approving the Arizona toxicity policy. EPA 
will take these comments into account as we further refine the 
implementation of toxicity narrative standards in National Pollutant 
Discharge Elimination System permits in Arizona.

E. Endangered Species Act

    Pursuant to section 7 of the Endangered Species Act (16 U.S.C. 1656 
et seq.), Federal agencies must assure that their actions are unlikely 
to jeopardize the continued existence of listed threatened or 
endangered species or adversely affect designated critical habitat of 
such species. Today's action adds the fish consumption use to various 
waters which previously did not have the protections afforded by that 
designation, and establishes that a monitoring program will be 
undertaken to implement the State's narrative water quality criteria 
with respect to the effects of mercury on wildlife.
    EPA has completed section 7 consultation with the FWS regarding 
this action.

F. Executive Order 12866

    Under Executive Order 12866 (58 FR 51735, October 4, 1993) the 
Agency must determine whether the regulatory action is ``significant'' 
and therefore subject to Office of Management and Budget (OMB) review 
and the requirements of the Executive Order. The Order defines 
``significant regulatory action'' as one that is likely to result in a 
rule that may:
    (1) Have an annual effect on the economy of $100 million or more or 
adversely affect in a material way the economy, a sector of the 
economy, productivity, competition, jobs, the environment, public 
health or safety, of 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 of the rights and obligations of recipients 
thereof; or
    (4) Raise novel legal or policy issues arising out of legal 
mandates, the

[[Page 20693]]

President's priorities, or the principles set forth in the Executive 
Order.
    Because the annualized cost of this final rule would be 
significantly less than $100 million and would meet none of the other 
criteria specified in the Executive Order, it has been determined that 
this rule is not a ``significant regulatory action'' under the terms of 
Executive Order 12866, and is therefore not subject to OMB review.

G. Executive Order 12875, Enhancing the Intergovernmental 
Partnership

    In compliance with Executive Order 12875 EPA has involved state, 
local, and tribal governments in the development of this rule. EPA, 
Region 9, consulted with ADEQ through conference calls, meetings and 
review of draft and final documents. EPA held a meeting on December 14, 
1995, in Phoenix, AZ, with members of the potentially impacted public 
(e.g., municipalities, industries and environmental groups) to discuss 
the proposed action. EPA held a public hearing on the proposed action 
on February 29, 1996.

H. Regulatory Flexibility Act

    The Regulatory Flexibility Act (5 U.S.C. 601 et seq.) requires EPA 
to assess whether its regulations create a disproportionate effect on 
small entities. Among its provisions, the Act directs EPA to prepare 
and publish an initial regulatory flexibility analysis (IRFA) for any 
proposed rule which may have a significant impact on a substantial 
number of small entities. For purposes of this rulemaking, small 
entities are small dischargers, whether industrial or municipal.
    Pursuant to section 605(b) of the Regulatory Flexibility Act (5 
U.S.C. 605(b)), the Administrator certifies that this rule will not 
have a significant economic impact on a substantial number of small 
entities. This rule is limited to the designation of the fish 
consumption use for fourteen waters within Arizona, and the requirement 
that EPA or Arizona implement a monitoring program to assess attainment 
of a specified State-adopted water quality standard. In light of the 
limited geographic scope of the use designations included in the final 
rule adopted by EPA (i.e., fourteen waterbodies), the Agency does not 
believe that there will be significant impacts associated with this 
aspect of the rule. The mercury monitoring program, moreover, will be 
carried out by EPA and ADEQ, and does not itself impose any additional 
obligations on small entities.

I. Unfunded Mandates Reform Act

    Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public 
Law 104-4, establishes requirements for Federal agencies to assess the 
effects of their regulatory actions on State, local, and tribal 
governments and the private sector. Under section 202 of the UMRA, EPA 
generally must prepare a written statement, including a cost-benefit 
analysis, for proposed and final rules with ``Federal mandates'' that 
may result in expenditures to State, local, and tribal governments, in 
the aggregate, or to the private sector, of $100 million or more in any 
one year. Before promulgating an EPA rule for which a written statement 
is needed, section 205 of the UMRA generally requires EPA to identify 
and consider a reasonable number of regulatory alternatives and adopt 
the least costly, most cost-effective or least burdensome alternative 
that achieves the objectives of the rule. The provisions of section 205 
do not apply when they are inconsistent with applicable law. Moreover, 
section 205 allows EPA to adopt an alternative other than the least 
costly, most cost-effective or least burdensome alternative if the 
Administrator publishes with the final rule an explanation why that 
alternative was not adopted. Before EPA establishes any regulatory 
requirements that may significantly or uniquely affect small 
governments, including tribal governments, it must have developed under 
section 203 of the UMRA a small government agency plan. The plan must 
provide for notifying potentially affected small governments, enabling 
officials of affected small governments to have meaningful and timely 
input in the development of EPA regulatory proposals with significant 
Federal intergovernmental mandates, and informing, educating, and 
advising small governments on compliance with the regulatory 
requirements.
    As noted above, this rule is limited to the designation of the fish 
consumption use for fourteen waters within Arizona, and the requirement 
that EPA or Arizona implement a monitoring program to assess attainment 
of a State-adopted water quality standard. EPA has determined that this 
rule contains no regulatory requirements that might significantly or 
uniquely affect small governments. EPA has also determined that this 
rule does not contain a Federal mandate that may result in expenditures 
of $100 million or more for State, local, and tribal governments, in 
the aggregate, or the private sector in any one year. Thus, today's 
rule is not subject to the requirements of sections 202 and 205 of the 
UMRA.

J. Paperwork Reduction Act

    This action requires no information collection activities subject 
to the Paperwork Reduction Act, and therefore no information collection 
request (ICR) will be submitted to the Office of Management and Budget 
(OMB) for review in compliance with the Paperwork Reduction Act, 44 
U.S.C. 3501 et seq. 

List of Subjects in 40 CFR Part 131

    Environmental protection, Water pollution control, Water quality 
standards, Toxic pollutants.

    Dated: April 29, 1996.
Carol M. Browner,
Administrator.
    For the reasons set out in the preamble, part 131 of title 40 of 
the Code of Federal Regulations is amended as follows:

PART 131--WATER QUALITY STANDARDS

    1. The authority citation for part 131 continues to read as 
follows:

    Authority: 33 U.S.C. 1251 et seq.

Subpart D--[Amended]

    2. Section 131.31 is amended by adding paragraphs (b), and (c), to 
read as follows:


Sec. 131.31  Arizona.

* * * * *
    (b) The following waters have, in addition to the uses designated 
by the State, the designated use of fish consumption as defined in R18-
11-101 (which is available from the Arizona Department of Environmental 
Quality, Water Quality Division, 3033 North Central Ave., Phoenix, AZ 
85012):

COLORADO MAIN STEM RIVER BASIN:
    Hualapai Wash
MIDDLE GILA RIVER BASIN:
    Agua Fria River (Camelback Road to Avondale WWTP)
    Galena Gulch
    Gila River (Felix Road to the Salt River)
    Queen Creek (Headwaters to the Superior WWTP)
    Queen Creek (Below Potts Canyon)
SAN PEDRO RIVER BASIN:
    Copper Creek
SANTA CRUZ RIVER BASIN:
    Agua Caliente Wash
    Nogales Wash
    Sonoita Creek (Above the town of Patagonia)
    Tanque Verde Creek
    Tinaja Wash
    Davidson Canyon
UPPER GILA RIVER BASIN

[[Page 20694]]

    Chase Creek

    (c) To implement the requirements of R18-11-108.A.5 with respect to 
effects of mercury on wildlife, EPA (or the State with the approval of 
EPA) shall implement a monitoring program to assess attainment of the 
water quality standard.

[FR Doc. 96-11080 Filed 5-6-96; 8:45 am]
BILLING CODE 6560-50-P