[Federal Register Volume 62, Number 98 (Wednesday, May 21, 1997)]
[Proposed Rules]
[Pages 27707-27710]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-13325]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 131

[FRL-5827-8]


Withdrawal From Federal Regulations of the Applicability to 
Alaska of Arsenic Human Health Criteria

AGENCY: Environmental Protection Agency.

ACTION: Proposed rule and request for comments.

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SUMMARY: In 1992, EPA promulgated federal regulations establishing 
water quality criteria for toxic pollutants for several states, 
including Alaska (40 CFR 131.36). In this action, EPA is proposing to 
withdraw the applicability to Alaska of the federal human health 
criteria for arsenic. EPA is providing an

[[Page 27708]]

opportunity for public comment on withdrawal of the federal criteria 
because the state's arsenic criteria differ from the federal criteria.

DATES: EPA will accept public comments on its proposed withdrawal of 
the human health criteria for arsenic applicable to Alaska until July 
7, 1997. Comments postmarked after this date may not be considered.

ADDRESSES: An original plus 2 copies, and if possible an electronic 
version of comments either in WordPerfect or ASCII format, should be 
addressed to Sally Brough, U.S. EPA Region 10, Office of Water, 1200 
Sixth Avenue, Seattle, Washington, 98101.
    The official administrative record for the consideration of this 
proposal for arsenic is available for public inspection at EPA Region 
10, Office of Water, 1200 Sixth Avenue, Seattle, Washington, 98101, 
between 8:00 a.m. and 4:30 p.m. Copies of the record are also available 
for public inspection at EPA's Alaska Operations Offices: 222 West 7th 
Avenue, Anchorage, AK and 410 Willoughby Avenue, Janeau, AK.

FOR FURTHER INFORMATION CONTACT: Fred Leutner at EPA Headquarters, 
Office of Water (4305), 401 M Street, SW, Washington, DC, 20460 
(telephone: 202-260-1542), or Sally Brough in EPA's Region 10 
(telephone: 206-553-1295).

SUPPLEMENTARY INFORMATION:

Potentially Affected Entities

     Citizens concerned with water quality in Alaska, and with 
pollution from arsenic in particular, may be interested in this 
proposed rulemaking. Since criteria are used in determining NPDES 
permit limits, entities discharging arsenic to waters of the United 
States in Alaska could be affected by this proposed rulemaking. 
Potentially affected entities include:

------------------------------------------------------------------------
                                                Examples of affected    
                 Category                             entities          
------------------------------------------------------------------------
Industry..................................  Industries discharging      
                                             arsenic to surface waters  
                                             in Alaska.                 
Municipalities............................  Publicly-owned treatment    
                                             works discharging arsenic  
                                             to surface waters in       
                                             Alaska.                    
------------------------------------------------------------------------

    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities likely to be affected by this 
action. This table lists the types of entities that EPA is now aware 
could potentially be affected by this action. Other types of entities 
not listed in the table could also be affected. To determine whether 
your facility could be affected by this action, you should carefully 
examine the applicability criteria in Sec. 131.36 of title 40 of the 
Code of Federal Regulations. If you have any questions regarding the 
applicability of this action to a particular entity, consult the person 
listed in the preceding FOR FURTHER INFORMATION CONTACT section.

Background

    On December 22, 1992, the Environmental Protection Agency (EPA or 
Agency) promulgated a rule to establish federal water quality criteria 
for priority toxic pollutants applicable in 14 states. That rule, which 
is commonly called the National Toxics Rule (NTR), is codified at 40 
CFR 131.36. The specific requirements for Alaska are codified at 
Sec. 131.36(d)(12) and among other criteria, include water quality 
criteria for the protection of human health from arsenic. EPA 
promulgated a human health criterion for Alaska of 0.18 g/L to 
protect waters designated for water consumption (i.e., sources of 
drinking water) plus the consumption of aquatic life which includes 
fish and shellfish such as shrimp, clams, oysters and mussels. This 
criterion is located in column D1 in the criteria matrix at section 
131.36(b)(1). EPA also promulgated a criterion of 1.4 g/L for 
waters designated for the human consumption of aquatic life without 
considering water consumption. This criterion is located in column D2 
in the criteria matrix. These concentrations are designed to not exceed 
an excess lifetime cancer risk of 1 in 100,000 (or 10-5) and 
reflects Alaska's preference in recent rule adoptions and in 
correspondence with EPA's Region 10. See 57 FR 60848, 60867.
    EPA's criteria for human health protection from arsenic toxicity 
used in the NTR were based on carcinogenic effects. Alaska had adopted 
by reference EPA's published Clean Water Act (CWA) section 304(a) 
criteria for human health into the state's water quality standards. 
However, EPA's criteria guidance for carcinogens was presented at 3 
different cancer risk levels, and the state had never officially 
adopted a specific cancer risk level. Accordingly, since Alaska did not 
have human health criteria for arsenic in place, EPA promulgated such 
criteria for the state in the NTR.
    Subsequent to the promulgation of the NTR, a number of issues and 
uncertainties arose concerning the health effects of arsenic. EPA 
determined that these issues and uncertainties were sufficiently 
significant to necessitate a careful evaluation of the risks of arsenic 
exposure. Accordingly EPA has undertaken a number of activities aimed 
at reassessing the risks to human health from arsenic. [See Basis and 
Purpose section below.]
    In light of EPA's review of the health effects of arsenic, the 
State of Alaska has proposed that the Safe Drinking Water Act (SDWA) 
maximum contaminant level (MCL) for arsenic of 50 g/L 
currently in the state's water quality standards be used as meeting the 
requirements of the Clean Water Act in lieu of the current human health 
criteria in the NTR. As adopted by Alaska, the MCL for arsenic applies 
to all fresh waters that have the public water supply designated use. 
(According to the state, this includes all but 20 fresh-water 
segments.) For the reasons discussed subsequently, EPA finds that the 
MCL for arsenic in freshwaters designated for public water supply, in 
conjunction with Alaska's aquatic life criteria for arsenic, meets the 
requirements of the CWA, and accordingly proposes to withdraw the 
applicability to Alaska of the human health criteria for arsenic 
promulgated in the NTR.
    If EPA removes the applicability of the NTR arsenic human health 
criteria to Alaska, the state has in place a chronic marine aquatic 
life criterion of 36 g/L, a chronic freshwater aquatic life 
criterion of 190 g/L, and the freshwater criterion of the MCL 
of 50 g/L for waters designated for public water supply 
discussed above. The aquatic life criteria are in place for all of the 
state's marine and estuarine waters, and in those few cases where the 
MCL is not applicable in freshwaters.

Basis and Purpose

    There are a number of ongoing national activities that may affect 
and/or necessitate a future change in the arsenic criteria for both 
ambient and drinking water in Alaska. The National Academy of Sciences 
(NAS) has initiated a study of the health risks posed by arsenic in 
water. Results of the study are expected in the Spring of 1998. 
Moreover, EPA is in the process of re-evaluating the risk assessments 
for arsenic as part of a pilot program for reconfiguring the Integrated 
Risk Information System (IRIS). EPA originally planned this re-
evaluation to cover aspects of both cancer and non-cancer risks and to 
include examination of data not previously reviewed. With the 
initiation of the NAS study, EPA redirected the focus of the IRIS re-
evaluation to the application of the proposed revisions to EPA's 
Guidelines for Cancer Risk Assessment. The IRIS re-evaluation of 
arsenic is expected in

[[Page 27709]]

1997. EPA encourages the state to review its water quality criteria for 
arsenic as this new information becomes available.
    EPA has recognized the use of appropriate MCLs in establishing 
water quality standards under the CWA. Agency guidance notes the 
differences between the statutory factors for developing SDWA MCLs and 
CWA section 304(a) criteria, but provides that where human consumption 
of drinking water is the principal exposure to a toxic chemical, then 
an existing MCL may be an appropriate concentration limit. See guidance 
noticed in 54 FR 346, January 5, 1989. Similarly, the CWA section 
304(a) human health guidelines are consistent with this position. See 
45 FR 79318, November 28, 1980.
    To determine whether the MCL could appropriately be used in lieu of 
the NTR's human health criteria for arsenic, EPA has prepared an 
exposure analysis to estimate the significance of human consumption of 
fish and shellfish containing the amounts of inorganic arsenic 
indicated as present in representative samples of fish and shellfish, 
in conjunction with the consumption of water containing concentrations 
of arsenic currently existing in the Nation's waters. See EPA's 
``Arsenic and Fish Consumption Concerns'' in the administrative record 
for this rulemaking. This analysis first recognizes that the most 
important toxic form of arsenic is inorganic arsenic. Inorganic arsenic 
is the principal form in surface waters and almost the exclusive form 
in ground waters. However, the arsenic in fish and most shellfish is 
largely present as organic arsenic (mostly arsenobetaine). Available 
information indicates that arsenobetaine passes through these organisms 
with minimal retention in the fish and shellfish tissues.
    In the NTR, EPA based the promulgated criteria on the human health 
criteria methodology contained in the 1980 human health guidelines. To 
estimate the ambient water concentration of a pollutant that does not 
represent a significant risk to the public (i.e., the criteria levels), 
the methodology makes certain assumptions about human exposure to 
pollutants. The methodology assumes that for most people, drinking 
water intake is 2 liters per day, and that fish consumption is 6.5 
grams per day (a little less than one-half pound per month). The 
methodology incorporates a bioconcentration factor (BCF) to account for 
a pollutant's concentration in fish and shellfish tissue versus its 
concentration in the water. The methodology also assumes that all of 
the water and fish consumed is contaminated at the criteria levels (the 
``safe'' levels).
    Using these same exposure factors from the methodology, EPA has 
assessed the effect of using the arsenic MCL. Assuming that the 
concentration of arsenic in water is at the MCL of 50 g/L, 
most people would be exposed to 100 g of arsenic from their 
drinking water intake (i.e., 2 L/day  x  50 g/L = 100 
g/day), and 0.6 g/day of inorganic arsenic from 
consuming 6.5 grams of fish and shellfish collected from water at the 
arsenic MCL concentration and assuming the BCF used in the NTR. (See 
derivation in EPA's ``Arsenic and Fish Consumption Concerns'' in the 
record.) The total estimated exposure would be 100.6 g/day 
which could consist entirely of inorganic arsenic. EPA considers the 
small increment of exposure from fish consumption to be insignificant. 
EPA therefore concludes that when applied to fresh waters in Alaska, 
use of 50 g/L generally provides a level of protection 
equivalent to that provided by the MCL. A full characterization of 
other exposure scenarios is contained in EPA's exposure analysis 
described above. This analysis is in the administrative record for this 
proposal and is currently undergoing external peer review. The results 
of the peer review will be considered before final action is taken on 
this rule.
    For regions in Alaska where high levels of arsenic in the potable 
water are accompanied by high levels of fish and shellfish consumption, 
the State of Alaska should develop site-specific criteria for the 
surface waters involved considering the arsenic content of the drinking 
water and fish consumed. In developing site-specific criteria the state 
should characterize the size and location of the population of concern 
and determine their fish/shellfish and water intake rates. The fish and 
shellfish consumption should consider the species and dietary intake on 
a per species basis. Actual total arsenic and inorganic arsenic values 
for the species consumed and actual concentrations in drinking water 
should be used in the exposure calculations whenever possible.
    The Agency solicits comment on whether there are any locations in 
Alaska where the arsenic criteria in the NTR should not be removed. For 
such locations, EPA solicits data documenting such existing conditions 
which indicate that fish consumers may be at an unacceptable risk of 
arsenic toxicity, and whether some other site-specific arsenic human 
health criteria may be appropriate. EPA solicits any information such 
as that described above concerning possible site-specific criteria to 
be developed by the State of Alaska.

Regulatory Procedural Information

    This proposed withdrawal of human health criteria for arsenic in 
Alaska is deregulatory in nature and would impose no additional 
regulatory requirements or costs. Therefore, it has been determined 
that this proposed action is not a ``significant regulatory action'' 
under the terms of Executive Order 12866 and is therefore not subject 
to OMB review.
    Based on the fact that this action is deregulatory in nature and 
would impose no regulatory requirements or costs, pursuant to section 
605(b) of the Regulatory Flexibility Act, the Administrator certifies 
that this action will not have a significant economic impact on a 
substantial number of small entities. EPA has determined that this 
action 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 to the private sector in any one 
year. EPA has also determined that this action contains no regulatory 
requirements that might significantly or uniquely affect small 
governments. Thus, today's action is not subject to the requirements of 
sections 202, 203 and 205 of the UMRA.
    This proposed rule does not impose any requirement subject to the 
Paperwork Reduction Act.

List of Subjects in 40 CFR Part 131

    Environmental protection, Water pollution control, Water quality 
standards.

    Dated: May 14, 1997.
Carol M. Browner,
Administrator.

    For the reasons set out in the preamble, title 40, chapter I, part 
131 of the Code of Federal Regulations is proposed to be 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.


Sec. 131.36  [Amended]

    2. In Sec. 131.36(d)(12)(ii) the table is amended under the heading 
``Applicable Criteria'', in the entry for ``Column D1'' and three 
entries for

[[Page 27710]]

``Column D2'' by removing the number ``2'' from the list of numbers.

[FR Doc. 97-13325 Filed 5-20-97; 8:45 am]
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