Document ID: EPA-HQ-OW-2015-0804-0001
Agency: epa
Document Type: Proposed Rule
Title: Proposal of Certain Federal Water Quality Standards Applicable to Maine
Posted Date: 2016-04-20T04:00Z

[Federal Register Volume 81, Number 76 (Wednesday, April 20, 2016)]
[Proposed Rules]
[Pages 23239-23267]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-09025]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 131

[EPA-HQ-OW-2015-0804; FRL-9945-03-OW]
RIN 2040-AF59

Proposal of Certain Federal Water Quality Standards Applicable to 
Maine

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) proposes federal 
Clean Water Act (CWA) water quality standards (WQS) that would apply to 
certain waters under the state of Maine's jurisdiction. EPA proposes 
human health criteria (HHC) to protect the sustenance fishing use in 
those waters in Indian lands and for waters subject to sustenance 
fishing rights under the Maine Implementing Act (MIA) based on a fish 
consumption rate that represents an unsuppressed level of fish 
consumption by the four federally recognized tribes. EPA proposes six 
additional WQS for waters in Indian lands in Maine, two WQS for all 
waters in Maine including waters in Indian lands, and one WQS for 
waters in Maine outside of Indian lands. These proposed WQS take into 
account the best available science, including local and regional 
information, as well as applicable EPA policies, guidance, and legal 
requirements, to protect human health and aquatic life. EPA proposes 
these WQS to address various disapprovals of Maine's standards that EPA 
issued in February, March, and June 2015, and to address the 
Administrator's determination that Maine's disapproved HHC are not 
adequate to protect the designated use of sustenance fishing for 
certain waters.

DATES: Comments must be received on or before June 20, 2016.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-OW-
2015-0804 at http://www.regulations.gov. Follow the online instructions 
for submitting comments. Once submitted, comments cannot be edited or 
removed from Regulations.gov. EPA may publish any comment received to 
its public docket. Do not submit electronically any information you 
consider to be Confidential Business Information (CBI) or other 
information whose disclosure is restricted by statute. Multimedia 
submissions (audio, video, etc.) must be accompanied by a written 
comment. The written comment is considered the official comment and 
should include discussion of all points you wish to make. EPA will 
generally not consider comments or comment contents located outside of 
the primary submission (i.e. on the Web, cloud, or other file sharing 
system). For additional submission methods, the full EPA public comment 
policy, information about CBI or multimedia submissions, and general 
guidance on making effective comments, please visit http://www.epa.gov/dockets/commenting-epa-dockets. EPA is offering two virtual public 
hearings so that interested parties may also provide oral comments on 
this proposed rule. The first hearing will be on Tuesday, June 7, 2016 
from 5:00 p.m. to 7:00 p.m. Eastern Daylight Time. The second hearing 
will be on Thursday, June 9, 2016 from 9:00 a.m. to 11:00 a.m. Eastern 
Daylight Time. For more details on the public hearings and a link to 
register, please visit http://www.epa.gov/wqs-tech/proposed-rule-maine-water-quality-standards.

FOR FURTHER INFORMATION CONTACT: Jennifer Brundage, Office of Water, 
Standards and Health Protection Division (4305T), Environmental 
Protection Agency, 1200 Pennsylvania Avenue NW., Washington, DC 20460; 
telephone number: (202) 566-1265; email address: 
Brundage.jennifer@epa.gov.

SUPPLEMENTARY INFORMATION: This proposed rule is organized as follows:

I. General Information
    Does this action apply to me?
II. Background
    A. Statutory and Regulatory Background
    B. EPA's Disapprovals of Portions of Maine's Water Quality 
Standards
    C. Scope of Waters
    D. Applicability of EPA Promulgated Water Quality Standards When 
Final
III. CWA 303(c)(4)(B) Determination of Necessity for Human Health 
Criteria That Protect Sustenance Fishing
IV. Proposed Water Quality Standards
    A. Proposed WQS for Waters in Indian Lands in Maine and for 
Waters Outside of Indian Lands in Maine Where the Sustenance Fishing 
Designated Use Established by 30 M.R.S. 6207(4) and (9) Applies
    B. Proposed WQS for Waters in Indian Lands in Maine
    C. Proposed WQS for All Waters in Maine
    D. Proposed WQS for Waters in Maine Outside of Indian Lands
V. Economic Analysis
    A. Identifying Affected Entities
    B. Method for Estimating Costs
    C. Results
VI. Statutory and Executive Order Reviews
    A. Executive Order 12866 (Regulatory Planning and Review) and 
Executive Order 13563 (Improving Regulation and Regulatory Review)
    B. Paperwork Reduction Act

[[Page 23240]]

    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132
    F. Executive Order 13175 (Consultation and Coordination With 
Indian Tribal Governments)
    G. Executive Order 13045 (Protection of Children From 
Environmental Health and Safety Risks)
    H. Executive Order 13211 (Actions That Significantly Affect 
Energy Supply, Distribution, or Use)
    I. National Technology Transfer and Advancement Act of 1995
    J. Executive Order 12898 (Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations)

I. General Information

Does this action apply to me?

    Entities such as industries, stormwater management districts, or 
publicly owned treatment works (POTWs) that discharge pollutants to 
waters of the United States in Maine could be indirectly affected by 
this rulemaking, because federal WQS promulgated by EPA are applicable 
to CWA regulatory programs, such as National Pollutant Discharge 
Elimination System (NPDES) permitting. Citizens concerned with water 
quality in Maine, including members of the federally recognized Indian 
tribes in Maine, could also be interested in this rulemaking. 
Dischargers that could potentially be affected include the following:

      Table 1--Dischargers Potentially Affected by This Rulemaking
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                                      Examples of potentially affected
             Category                             entities
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Industry..........................  Industries discharging pollutants to
                                     waters of the United States in
                                     Maine.
Municipalities....................  Publicly owned treatment works or
                                     other facilities discharging
                                     pollutants to waters of the United
                                     States in Maine.
Stormwater Management Districts...  Entities responsible for managing
                                     stormwater runoff in the state of
                                     Maine.
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    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities that could be indirectly affected 
by this action. Any parties or entities who depend upon or contribute 
to the water quality of Maine's waters could be affected by this 
proposed rule. To determine whether your facility or activities could 
be affected by this action, you should carefully examine this proposed 
rule. If you have questions regarding the applicability of this action 
to a particular entity, consult the person listed in the FOR FURTHER 
INFORMATION CONTACT section.

II. Background

A. Statutory and Regulatory Background

1. Clean Water Act (CWA)
    CWA section 101(a)(2) establishes as a national goal ``water 
quality which provides for the protection and propagation of fish, 
shellfish, and wildlife, and recreation in and on the water, wherever 
attainable.'' These are commonly referred to as the ``fishable/
swimmable'' goals of the CWA. EPA interprets ``fishable'' uses to 
include, at a minimum, designated uses providing for the protection of 
aquatic communities and human health related to consumption of fish and 
shellfish.\1\
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    \1\ USEPA. 2000. Memorandum #WQSP-00-03. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC. http://water.epa.gov/scitech/swguidance/standards/upload/2000_10_31_standards_shellfish.pdf.
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    CWA section 303(c) (33 U.S.C. 1313(c)) directs states to adopt 
water quality standards (WQS) for waters under their jurisdiction 
subject to the CWA. CWA section 303(c)(2)(A) and EPA's implementing 
regulations at 40 CFR part 131 require, among other things, that a 
state's WQS specify appropriate designated uses of the waters, and 
water quality criteria to protect those uses that are based on sound 
scientific rationale. EPA's regulations at 40 CFR 131.11(a)(1) provide 
that such criteria ``must be based on sound scientific rationale and 
must contain sufficient parameters or constituents to protect the 
designated use.'' In addition, 40 CFR 131.10(b) provides that ``[i]n 
designating uses of a water body and the appropriate criteria for those 
uses, the state shall take into consideration the water quality 
standards of downstream waters and ensure that its water quality 
standards provide for the attainment and maintenance of the water 
quality standards of downstream waters.''
    States are required to review applicable WQS at least once every 
three years and, if appropriate, revise or adopt new standards (CWA 
section 303(c)(1)). Any new or revised WQS must be submitted to EPA for 
review, to determine whether it meets the CWA's requirements, and for 
approval or disapproval (CWA section 303(c)(2)(A) and (c)(3)). If EPA 
disapproves a state's new or revised WQS, the CWA provides the state 
ninety days to adopt a revised WQS that meets CWA requirements, and if 
it fails to do so, EPA shall promptly propose and then promulgate such 
standard unless EPA approves a state replacement WQS first (CWA section 
303(c)(3) and (c)(4)(A)). If the state adopts and EPA approves a state 
replacement WQS after EPA promulgates a standard, EPA then withdraws 
its promulgation. CWA section 303(c)(4)(B) authorizes the Administrator 
to determine, even in the absence of a state submission, that a new or 
revised standard is necessary to meet CWA requirements. Upon making 
such a determination, EPA shall promptly propose, and then within 
ninety days promulgate, any such new or revised standard unless prior 
to such promulgation, the state has adopted a revised or new WQS which 
EPA determines to be in accordance with the CWA.
    Under CWA section 304(a), EPA periodically publishes water quality 
criteria recommendations for states to consider when adopting water 
quality criteria for particular pollutants to protect the CWA section 
101(a)(2) goal uses. For example, in 2015, EPA updated its 304(a) 
recommended criteria for human health for 94 pollutants (the 2015 
criteria update).\2\ Where EPA has published recommended criteria, 
states should consider adopting water quality criteria based on EPA's 
CWA section 304(a) criteria, section 304(a) criteria modified to 
reflect site-specific conditions, or other scientifically defensible 
methods (40 CFR 131.11(b)(1)). CWA section 303(c)(2)(B) requires states 
to adopt numeric criteria for all toxic pollutants listed pursuant to 
CWA section 307(a)(1) for which EPA has published 304(a) criteria, as 
necessary, to support the states' designated uses.
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    \2\ Final Updated Ambient Water Quality Criteria for the 
Protection of Human Health, (80 FR 36986, June 29, 2015). See also: 
USEPA. 2015. Final 2015 Updated National Recommended Human Health 
Criteria. U.S. Environmental Protection Agency, Office of Water, 
Washington, DC. http://water.epa.gov/scitech/swguidance/standards/criteria/current/hhfinal.cfm.

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[[Page 23241]]

2. Maine Indian Settlement Acts
    There are four federally recognized Indian tribes in Maine 
represented by five governing bodies. The Penobscot Nation and the 
Passamaquoddy Tribe have reservations and trust land holdings in 
central and coastal Maine. The Passamaquoddy Tribe has two governing 
bodies, one on the Pleasant Point Reservation and another on the Indian 
Township Reservation. The Houlton Band of Maliseet Indians and the 
Aroostook Band of Micmacs have trust lands further north in the state. 
To simplify the discussion of the legal framework that applies to each 
Tribe's territory, EPA will refer to the Penobscot Nation and the 
Passamaquoddy Tribe together as the ``Southern Tribes'' and the Houlton 
Band of Maliseet Indians and Aroostook Band of Micmacs as the 
``Northern Tribes.'' EPA acknowledges that these are collective 
appellations the tribes themselves have not adopted, and the Agency 
uses them solely to simplify this discussion.
    In 1980, Congress passed the Maine Indian Claims Settlement Act 
(MICSA) that resolved litigation in which the Southern Tribes asserted 
land claims to a large portion of the state of Maine. 25 U.S.C. 1721, 
et seq. MICSA ratified a state statute passed in 1979, the Maine 
Implementing Act (MIA, 30 M.R.S. 6201, et seq.), which was designed to 
embody the agreement reached between the state and the Southern Tribes. 
In 1981, MIA was amended to include provisions for land to be taken 
into trust for the Houlton Band of Maliseet Indians, as provided for in 
MICSA. 30 M.R.S. 6205-A; 25 U.S.C. 1724(d)(1). Since it is Congress 
that has plenary authority as to federally recognized Indian tribes, 
MIA's provisions concerning jurisdiction and the status of the tribes 
are effective as a result of, and consistent with, the Congressional 
ratification in MICSA.
    In 1989, the Maine legislature passed the Micmac Settlement Act 
(MSA) to embody an agreement as to the status of the Aroostook Band of 
Micmacs. 30 M.R.S. 7201, et seq. In 1991, Congress passed the Aroostook 
Band of Micmacs Settlement Act (ABMSA), which ratified the MSA. 25 
U.S.C. 1721, Act Nov. 26, 1991, Public Law 102-171, 105 Stat. 1143. One 
principal purpose of both statutes was to give the Micmacs the same 
settlement that had been provided to the Maliseets in MICSA. See ABMSA 
2(a)(4) and (5). In 2007, the U.S. Court of Appeals for the First 
Circuit confirmed that the Micmacs and Maliseets are subject to the 
same jurisdictional provisions in MICSA. Aroostook Band of Micmacs v. 
Ryan, 484 F.3d 41 (1st Cir. 2007). Where appropriate, this preamble 
discussion will refer to the combination of MICSA, MIA, ABMSA, and MSA 
as the ``settlement acts.''
    As discussed in greater detail in EPA's February 2, 2015, decision 
disapproving certain Maine WQS in waters in Indian lands, a key purpose 
of the settlement acts was to confirm and expand the Tribes' land base, 
in the form of both reservations and trust lands, so that the Tribes 
may preserve their culture and sustenance practices, including 
sustenance fishing. For the Passamaquoddy Tribe and Penobscot Nation, 
the settlement acts expressly confirmed an aboriginal right to 
sustenance fishing in their reservations. See 30 M.R.S. 6207(4).
    The legislative record of the settlement acts makes clear that 
Congress also intended to ensure the tribes' continuing ability to 
practice their traditional sustenance lifeways, including fishing, from 
their trust lands. With regard to the Passamaquoddy and Penobscot trust 
lands, legislative intent to provide for tribal sustenance fishing 
practices is, for example, reflected in MIA provisions which grant 
tribal control of fishing in certain trust waters and require the 
consideration of tribal sustenance practices in the setting of fishing 
regulations for the remaining trust waters. See 30 M.R.S. 6207(1), (3). 
As for the Micmacs and Maliseets, the settlement acts similarly provide 
for the opportunity to continue their sustenance fishing practices, 
though subject to more direct state regulation than that of the 
Passamaquoddy or Penobscot. In its February 2, 2015, decision, EPA 
concluded that MICSA directly provides the state with jurisdiction to 
set WQS in the Northern Tribes' trust lands and that MICSA also 
ratifies provisions of MIA that provide the state with such authority 
in the Southern Tribes' territories. That decision provided a detailed 
explanation of the legal basis for the state's jurisdiction to set WQS 
in waters in Indian lands in Maine. Because of the unique 
jurisdictional formula Congress ratified in the settlement acts, EPA is 
in the unusual position of reviewing state WQS in waters in Indian 
lands.\3\
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    \3\ Generally, the norm elsewhere in the country is that EPA has 
authority to set WQS for Indian country waters, with tribes that 
have obtained treatment in a manner similar to a state under CWA 
section 518 gaining authority to set WQS for their reservations.
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    Having disapproved certain state WQS longer than ninety days ago, 
as explained in section II.B., EPA is required by the CWA to promptly 
propose and then promulgate federal standards unless, in the meantime, 
the state adopts and EPA approves state replacement WQS that address 
EPA's disapproval.

B. EPA's Disapprovals of Portions of Maine Water Quality Standards

    On February 2, March 16, and June 5, 2015, EPA disapproved a number 
of Maine's new and revised WQS. These disapproval letters are available 
in the docket for this rulemaking. These decisions were prompted by an 
on-going lawsuit initiated by Maine against EPA. As discussed further 
below, some of the disapprovals applied only to waters in Indian lands 
in Maine, while others applied to waters throughout the state or to 
waters in the state outside of Indian lands.\4\ EPA concluded that the 
disapproved WQS did not adequately protect designated uses related to 
the protection of human health and/or aquatic life. EPA requested that 
the state revise its WQS to address the issues identified in the 
disapprovals. The statutory 90-day timeframe provided to the state to 
revise its WQS has passed with respect to all of the disapproved WQS. 
The state has filed an amended complaint as part of an ongoing lawsuit 
challenging EPA's February 2, 2015 disapprovals. Discussed below are 
those disapprovals for which EPA today proposes new and revised WQS.\5\
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    \4\ As discussed above, unlike in other states, Maine has the 
authority to promulgate WQS for waters in Indian lands in Maine, as 
a result of state and federal statutes that resolved the land claims 
of tribes in Maine.
    \5\ EPA's March and June decisions included several disapprovals 
for which no promulgation is necessary, and therefore those 
disapprovals are not discussed herein. Those disapprovals related to 
certain pesticide and chemical discharge provisions, certain 
exceptions to prohibitions on discharges to Class AA and SA waters, 
and the reclassification of a 0.3 mile segment of Long Creek that 
flows through Westbrook, Maine. In addition, EPA is not promulgating 
WQS related to certain HHC that EPA disapproved for the reasons 
discussed in section IV.A.1.c.
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1. Disapprovals That Apply Only to Waters in Indian Lands in Maine
    In its February 2015 decision, EPA concluded that MICSA granted the 
state authority to set WQS in waters in Indian lands. EPA also 
concluded that in assessing whether the state's WQS were approvable for 
waters in Indian lands, EPA must effectuate the CWA requirement that 
WQS must protect applicable designated uses and be based on sound 
science in consideration of the fundamental purpose for which land was 
set aside for the tribes under the Indian settlement acts in Maine. EPA 
found that those settlement acts, which include MICSA and other state 
and federal statutes that resolved Indian

[[Page 23242]]

land claims in the state, provide for land to be set aside as a 
permanent land base for the Indian tribes in Maine, in order for the 
tribes to be able to continue their unique cultures, including the 
ability to exercise sustenance fishing practices. Accordingly, EPA 
interprets the state's ``fishing'' designated use, as applied to waters 
in Indian lands, to mean ``sustenance fishing'' and approved it as 
such; and EPA approved a specific sustenance fishing right reserved in 
one of the settlement acts as a designated use for certain tribal 
reservation waters. Against this backdrop, EPA approved or disapproved 
all of Maine's WQS as applied to waters in Indian lands after 
evaluating whether they satisfied CWA requirements as informed by the 
settlement acts.\6\ EPA's disapprovals of WQS for waters in Indian 
lands in Maine were based on two distinct rationales, depending on the 
WQS.
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    \6\ Because EPA had never previously acted on any Maine WQS for 
waters in Indian lands, they remained ``new or revised'' WQS as to 
those waters, even though EPA had approved many of them for other 
state waters. They were therefore subject to EPA review and approval 
or disapproval pursuant to CWA section 303(c).
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    First, EPA disapproved Maine's HHC for toxic pollutants based on 
EPA's conclusion that they do not adequately protect the health of 
tribal sustenance fishers in waters in Indian lands, because they are 
not based on the higher fish consumption rates that reflect the tribes' 
sustenance fishing practices, and, in the case of one HHC, because the 
cancer risk level was not adequately protective of the sustenance 
fishing use. These disapprovals, discussed in EPA's February and March 
decisions, are specifically related to unique aspects of the tribes' 
use of waters in Indian lands. EPA proposes to promulgate WQS related 
to the HHC disapprovals as explained in section IV.A.
    Second, EPA, in its March and June decisions, disapproved a number 
of WQS as applied to waters in Indian lands because those standards, 
although approved for other waters in Maine many years ago, no longer 
satisfy CWA requirements (i.e., they do not protect designated uses 
and/or are not based on sound scientific rationale). EPA proposes to 
promulgate six WQS related to those disapprovals, which include: (1) 
Narrative and numeric bacteria criteria for the protection of primary 
contact recreation and shellfishing; (2) ammonia criteria for 
protection of aquatic life in fresh waters; (3) a statutory exception 
for naturally occurring toxic substances from the requirement to 
regulate toxic substances at the levels recommended by EPA, as it 
applies to HHC, and a natural conditions clause, as it applies to HHC; 
(4) the mixing zone policy; (5) the pH criterion for fresh waters; and 
(6) tidal temperature criteria. Because EPA had previously approved 
these provisions for other waters in Maine, the disapprovals and 
corresponding proposed WQS apply to only waters in Indian lands.
2. Disapprovals That Apply to All Waters in Maine, Including Waters in 
Indian Lands
    In its March and June 2015 decisions, EPA disapproved a number of 
new and revised WQS as applied to all waters throughout Maine, 
including waters in Indian lands. These are WQS that EPA had not 
previously acted upon for any waters. EPA proposes two WQS for all 
waters in Maine related to the disapprovals of (1) a statute allowing 
the waiver or modification of protection and improvement laws, as it 
pertains to WQS; and (2) the numeric criteria for dissolved oxygen in 
Class A waters. EPA proposes one WQS for waters in Maine outside of 
Indian lands related to the disapproval of the phenol criterion for 
water plus organisms.\7\
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    \7\ EPA proposes a separate phenol criterion for water plus 
organisms for the waters in Indian lands.
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C. Scope of Waters

    To address the disapprovals discussed in section II.B.1, EPA 
proposes HHC for toxic pollutants as well as six other WQS that apply 
only to waters in Indian lands. For the purpose of this rulemaking, 
``waters in Indian lands'' are those waters in the tribes' reservations 
and trust lands as provided for in the settlement acts.
    In addition, as described below in section III, EPA proposes the 
same HHC for toxic pollutants pursuant to a determination of necessity 
under CWA 303(c)(4)(B) for the following waters: (1) Waters in Indian 
lands in the event that a court determines that EPA's disapprovals of 
HHC for such waters were unauthorized and that Maine's existing HHC are 
in effect; and (2) waters where there is a sustenance fishing 
designated use outside of waters in Indian lands.\8\
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    \8\ EPA has included in the docket for this rulemaking a 
Technical Support Document, entitled ``Scope of Waters,'' which 
provides further information regarding, for purposes of this 
proposed rulemaking, the waters that are included in the term 
``waters in Indian lands'' and the waters where the designated use 
of sustenance fishing applies.
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D. Applicability of EPA Promulgated Water Quality Standards When Final

    Once finalized, EPA's water quality standards would apply to the 
relevant waters for CWA purposes. Although EPA proposes WQS to address 
the standards that it disapproved or for which it has made a 
determination, Maine continues to have the option to adopt and submit 
to EPA new or revised WQS that remedy the issues identified in the 
disapprovals and determination, consistent with CWA section 303(c) and 
EPA's implementing regulations at 40 CFR part 131. EPA encourages Maine 
to expeditiously adopt protective WQS that address the changes EPA 
identified in its disapprovals and determination, discussed in section 
III, as being necessary to meet CWA requirements. Consistent with CWA 
section 303(c)(4), if Maine adopts and submits new or revised WQS and 
EPA approves them before finalizing this proposed rule, EPA would not 
proceed with the final rulemaking for those waters and/or pollutants 
for which EPA approves Maine's new or revised standards.
    If EPA finalizes this proposed rule, and Maine subsequently adopts 
and submits new or revised WQS that EPA finds meet CWA requirements, 
EPA proposes that once EPA approves Maine's WQS, they would become 
effective for CWA purposes, and EPA's corresponding promulgated WQS 
would no longer apply. EPA would still undertake a rulemaking to 
withdraw the federal WQS for those pollutants, but any delay in that 
process would not delay Maine's approved WQS from becoming the sole 
applicable WQS for CWA purposes. EPA solicits comment on this approach.

III. CWA 303(c)(4)(B) Determination of Necessity for HHC That Protect 
Sustenance Fishing

    Per EPA's regulations at 40 CFR 131.11(a), water quality criteria 
must be sufficient to protect the designated uses. As discussed in 
section II.A.2. and in EPA's February 2015 disapproval, the settlement 
acts reflect Congress's intent that the tribes in Maine must be able to 
engage in sustenance fishing to preserve their culture and lifeways. In 
waters where the settlement acts provide for the tribes to engage in 
sustenance fishing, EPA interprets Maine's designated use of 
``fishing'' to include sustenance fishing, and EPA has further approved 
section 6207(4) and (9) of MIA as the establishment of a sustenance 
fishing designated use for fresh waters in the Southern Tribes' 
reservations.
    For the reasons discussed in EPA's February and March 2015 
disapproval decisions and summarized below in section IV.A.1.b., most 
of Maine's HHC for toxic pollutants are not adequate to protect the 
sustenance fishing designated use because they are based on a fish 
consumption rate that does not

[[Page 23243]]

reflect the tribes' unsuppressed sustenance fishing level of 
consumption. Accordingly, for the waters in Maine where there is a 
sustenance fishing designated use and Maine's existing HHC are in 
effect, EPA hereby determines under CWA section 303(c)(4)(B) that new 
or revised WQS for the protection of human health are necessary to meet 
the requirements of the CWA for such waters. EPA therefore proposes HHC 
for such waters in this rule in accordance with this section 
303(c)(4)(B) determination. The specific HHC to which this 
determination and corresponding proposal apply are set forth in Table 
3. This determination also applies to Maine's HHC for arsenic 
(including, specifically, Maine's cancer risk level of 10-4 for 
arsenic), thallium, and dioxin. As discussed in section IV.A.1.c., EPA 
is reserving its proposal for criteria for these three HHC until a 
later date, pending the outcome of additional scientific assessments.
    This determination applies to two groups of waters in Maine:
    1. Any waters in Indian lands in Maine for which a court in the 
future determines that EPA's 2015 disapprovals of HHC for such waters 
were unauthorized and that Maine's existing HHC are in effect. Maine 
has challenged EPA's disapprovals in federal district court, asserting 
that EPA did not have the authority to disapprove the HHC in waters in 
Indian lands. While EPA's position is that the disapprovals were 
authorized and Maine's existing HHC are not in effect, this 
determination ensures that EPA has the authority to promulgate the 
proposed HHC, and that the tribes' sustenance fishing use would be 
protected, even if Maine's challenge to EPA's disapproval authority 
were to prevail.
    2. Any water in Maine where sustenance fishing is a designated use 
but such water is determined not to be a ``water in Indian lands.'' \9\ 
EPA notes that there may be one or more waters where the sustenance 
fishing designated use based on MIA section 6207(4) and (9) extends 
beyond ``waters in Indian lands.'' See ``Scope of Waters'' Technical 
Support Document in the docket for this rulemaking. This determination 
and corresponding rulemaking apply to any water to which the sustenance 
fishing designated use based on MIA section 6207(4) and (9) applies 
that is beyond the scope of ``waters in Indian lands.''
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    \9\ In its February 2015 Decision, EPA concluded that section 
6207(4) and (9) of MIA constituted a new or revised water quality 
standard and approved the provision as a designated use of 
sustenance fishing applicable to all inland waters of the Southern 
Tribes' reservations in which populations of fish are or may be 
found. Accordingly, EPA's approval of MIA section 6207(4) and (9) as 
a designated use of sustenance fishing applies to all waters where 
the Southern Tribes have a right to sustenance fish, irrespective of 
whether such waters are determined to be outside of the scope of 
their reservation for purposes other than sustenance fishing.
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    EPA's determination is not itself a final action, nor part of a 
final action, at this time. After consideration of comments on the 
proposed rule, EPA will take final agency action on this rulemaking. It 
is at that time that any challenge to the determination and/or water 
quality standards applicable to Maine based on such determination may 
occur.

IV. Proposed Water Quality Standards

A. Proposed WQS for Waters in Indian Lands in Maine and for Waters 
Outside of Indian Lands in Maine Where the Sustenance Fishing 
Designated Use Established by 30 M.R.S. 6207(4) and (9) Applies

1. Human Health Criteria for Toxic Pollutants
    a. General Recommended Approach for Deriving HHC. HHC for toxic 
pollutants are designed to minimize the risk of adverse cancer and non-
cancer effects occurring from lifetime exposure to pollutants through 
the ingestion of drinking water and consumption of fish/shellfish 
obtained from inland and nearshore waters. EPA's practice is to 
establish 304(a) HHC for the combined activities of drinking water and 
consuming fish/shellfish obtained from inland and nearshore waters, and 
separate HHC for consuming only fish/shellfish originating from inland 
and nearshore waters. The latter criteria apply in cases where the 
designated uses of a waterbody include supporting fish/shellfish for 
human consumption but not drinking water supply sources (e.g., in non-
potable estuarine waters). The criteria are based on two types of 
biological endpoints: (1) Carcinogenicity and (2) systemic toxicity 
(i.e., all adverse effects other than cancer). EPA takes an integrated 
approach and considers both cancer and non-cancer effects when deriving 
HHC. Where sufficient data are available, EPA derives criteria using 
both carcinogenic and non-carcinogenic toxicity endpoints and 
recommends the lower value. HHC for carcinogenic effects are typically 
calculated using the following input parameters: cancer slope factor, 
excess lifetime cancer risk level, body weight, drinking water intake 
rate, fish consumption rate(s), and bioaccumulation factor(s). HHC for 
non-carcinogenic and nonlinear carcinogenic effects are typically 
calculated using reference dose, relative source contribution (RSC), 
body weight, drinking water intake rate, fish consumption rate(s) and 
bioaccumulation factor(s). Each of these inputs is discussed in more 
detail below, in EPA's 2000 Human Health Methodology (the ``2000 
Methodology''),\10\ and in the 2015 criteria update.\11\
---------------------------------------------------------------------------

    \10\ USEPA. 2000. Methodology for Deriving Ambient Water Quality 
Criteria for the Protection of Human Health. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC. EPA- 822-B-00-
004. http://www.epa.gov/waterscience/criteria/humanhealth/method/complete.pdf.
    \11\ Final Updated Ambient Water Quality Criteria for the 
Protection of Human Health, 80 FR 36986 (June 29, 2015). See also: 
USEPA. 2015. Final 2015 Updated National Recommended Human Health 
Criteria. U.S. Environmental Protection Agency, Office of Water, 
Washington, DC. http://water.epa.gov/scitech/swguidance/standards/criteria/current/hhfinal.cfm.
---------------------------------------------------------------------------

    i. Cancer Risk Level. For cancer-causing pollutants where the 
carcinogenic effects have a linear relationship to exposure, EPA's 
304(a) HHC generally assume that carcinogenicity is a ``non-threshold 
phenomenon,'' which means that there are no ``safe'' or ``no-effect'' 
levels of exposure because even extremely low levels of exposure to 
most known and suspect carcinogenic compounds are assumed to cause a 
finite increase in the risk of developing cancer over the course of a 
lifetime. As a matter of policy, EPA calculates its 304(a) HHC at 
concentrations corresponding to a 10-6 cancer risk level 
(CRL), meaning that if exposure were to occur as set forth in the 
304(a) methodology at the prescribed concentration over the course of 
one's lifetime, then the risk of developing cancer from the exposure as 
described would be one in a million on top of the background risk of 
developing cancer from all other exposures. EPA recommends cancer risk 
levels of 10-6 (one in a million) or 10-5 (one in 
one hundred thousand) for the general population and notes that states 
and authorized tribes can also choose a more protective risk level, 
such as 10-7 (one in ten million), when deriving HHC.
    ii. Cancer Slope Factor and Reference Dose. For noncarcinogenic 
toxicological effects, EPA uses a chronic-duration oral reference dose 
(RfD) to derive HHC. An RfD is an estimate (with uncertainty spanning 
perhaps an order of magnitude) of a daily oral exposure of the human 
population to a substance that is likely to be without an appreciable 
risk of deleterious effects during a lifetime. An RfD is typically 
derived from a laboratory animal dosing study in which a no-observed-
adverse-

[[Page 23244]]

effect level (NOAEL), lowest-observed-adverse-effect level (LOAEL), or 
benchmark dose can be obtained. Uncertainty factors are applied to 
reflect the limitations of the data.\12\ For carcinogenic toxicological 
effects, EPA uses an oral cancer slope factor (CSF) to derive HHC. The 
oral CSF is an upper bound, approximating a 95% confidence limit, on 
the increased cancer risk from a lifetime oral exposure to a stressor.
---------------------------------------------------------------------------

    \12\ USEPA. 2000. Methodology for Deriving Ambient Water Quality 
Criteria for the Protection of Human Health. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC. EPA- 822-B-00-
004.
---------------------------------------------------------------------------

    iii. Exposure Assumptions. In EPA's 2015 criteria update, EPA used 
a default drinking water intake rate of 2.4 liters per day (L/day) and 
a default rate of 22.0 g/day for total consumption of fish and 
shellfish from inland and nearshore waters. Additionally, pollutant-
specific bioaccumulation factors (BAFs) or bioconcentration factors 
(BCFs) were used to relate aqueous pollutant concentrations to 
predicted pollutant concentrations in the edible portions of ingested 
species.
    EPA's national default drinking water intake rate of 2.4 L/day 
represents the per capita estimate of combined direct and indirect 
community water ingestion at the 90th percentile for adults ages 21 and 
older.\13\ EPA's national default FCR of 22.0 g/day represents the 90th 
percentile consumption rate of fish and shellfish from inland and 
nearshore waters for the U.S. adult population 21 years of age and 
older, based on National Health and Nutrient Examination Survey 
(NHANES) data from 2003 to 2010.\14\ EPA calculates HHC using a default 
body weight of 80.0 kilograms (kg), the average weight of a U.S. adult 
age 21 and older, based on NHANES data from 1999 to 2006.\15\
---------------------------------------------------------------------------

    \13\ USEPA. 2011. EPA Exposure Factors Handbook. United States 
Environmental Protection Agency. Washington, DC EPA 600/R-090/052F. 
http://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=236252.
    \14\ USEPA. 2014. Estimated Fish Consumption Rates for the U.S. 
Population and Selected Subpopulations (NHANES 2003-2010). United 
States Environmental Protection Agency, Washington, DC, USA. EPA 
820-R-14-002.
    \15\ USEPA. 2011. EPA Exposure Factors Handbook. United States 
Environmental Protection Agency. Washington, DC EPA 600/R-090/052F. 
http://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=236252.
---------------------------------------------------------------------------

    Although EPA uses these default values to calculate national 304(a) 
HHC, EPA's 2000 Methodology notes a preference for the use of local 
data to calculate HHC (e.g., locally derived FCRs, drinking water 
intake rates and body weights, and waterbody-specific bioaccumulation 
rates) over national default values, where data are sufficient to do 
so.\16\ EPA also generally recommends, where sufficient data are 
available, selecting a FCR that reflects consumption that is not 
suppressed by concerns about the safety of available fish \17\ or fish 
availability. Deriving HHC using an unsuppressed FCR furthers the 
restoration goals of the CWA, and ensures protection of human health as 
pollutant levels decrease, fish habitats are restored, and fish 
availability increases. While EPA encourages doing so in general, where 
sustenance fishing is a designated use of the waters (due to, for 
example, tribal treaty or other federal law that provides for a tribe 
to fish for its sustenance), in EPA's scientific and policy judgment, 
selecting a FCR that reasonably represents current unsuppressed fish 
consumption based on the best currently available information is 
necessary and appropriate to ensure that such sustenance fishing use is 
protected. Such FCR must consider suppression and where adequate data 
are available to clearly demonstrate what that value is for the 
relevant population, the FCR must reflect that value. If sufficient 
data regarding unsuppressed fish consumption levels are not readily 
available, consultation with tribes is important to ensure that all 
data and information relevant to this issue are considered.
---------------------------------------------------------------------------

    \16\ USEPA. 2000. Methodology for Deriving Ambient Water Quality 
Criteria for the Protection of Human Health. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC. EPA-822-B-00-
004. http://www.epa.gov/waterscience/criteria/humanhealth/method/complete.pdf.
    \17\ USEPA. January 2013. Human Health Ambient Water Quality 
Criteria and Fish Consumption Rates: Frequently Asked Questions. 
http://water.epa.gov/scitech/swguidance/standards/criteria/health/methodology/upload/hhfaqs.pdf.
---------------------------------------------------------------------------

    iv. Relative Source Contribution. EPA's 2000 Methodology describes 
different approaches for addressing water and non-water exposure 
pathways to derive human health criteria depending on the toxicological 
endpoint of concern, the toxicological effect (noncarcinogenic or 
carcinogenic), and whether toxicity is considered a linear or threshold 
effect. Water sources of exposure include both consuming drinking water 
and eating fish or shellfish from inland and nearshore waters that have 
been exposed to pollutants in the water body. For pollutants that 
exhibit a threshold of exposure before deleterious effects occur, as is 
the case for noncarcinogens and nonlinear carcinogens, EPA applies a 
relative source contribution (RSC) to account for other potential human 
exposures to the pollutant.\18\ Other sources of exposure might 
include, but are not limited to, exposure to a particular pollutant 
from ocean fish or shellfish consumption (which is not included in the 
FCR), non-fish food consumption (e.g., consumption of fruits, 
vegetables, grains, meats, or poultry), dermal exposure, and inhalation 
exposure.
---------------------------------------------------------------------------

    \18\ USEPA. 2000. Methodology for Deriving Ambient Water Quality 
Criteria for the Protection of Human Health. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC. EPA- 822-B-00-
004.
---------------------------------------------------------------------------

    For substances for which the toxicity endpoint is carcinogenicity 
based on a linear low-dose extrapolation, only the exposures from 
drinking water and fish ingestion are reflected in HHC; that is, non-
water sources are not explicitly included and no RSC is applied.\19\ In 
these situations, HHC are derived with respect to the incremental 
lifetime cancer risk posed by the presence of a substance in water, 
rather than an individual's total risk from all sources of exposure. 
EPA derived a RSC (ranging from 0.2 to 0.8) for each chemical included 
in the 2015 criteria update, by using the Exposure Decision Tree 
approach described in the 2000 Methodology.\20\
---------------------------------------------------------------------------

    \19\ USEPA. 2000. Methodology for Deriving Ambient Water Quality 
Criteria for the Protection of Human Health. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC. EPA- 822-B-00-
004.
    \20\ USEPA. 2000. Methodology for Deriving Ambient Water Quality 
Criteria for the Protection of Human Health. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC. EPA- 822-B-00-
004. http://www.epa.gov/waterscience/criteria/humanhealth/method/complete.pdf.
---------------------------------------------------------------------------

    b. What did EPA disapprove? On February 2, 2015 and March 12, 2015, 
EPA disapproved Maine's HHC for toxic pollutants for waters in Indian 
lands because EPA found that they did not meet CWA requirements, i.e., 
they were not adequate to protect the designated use of sustenance 
fishing in those waters. EPA reached this conclusion by applying the 
CWA's requirements that water quality criteria protect designated uses 
and be based on a sound scientific rationale, in consideration of the 
purpose of the settlement acts discussed above to preserve the tribes' 
culture and sustenance practices. EPA determined that in order to 
protect the function of the waters in Indian lands to preserve the 
tribes' unique culture and to provide for the safe exercise of their 
sustenance practices, EPA must interpret Maine's designated use of 
``fishing'' to include sustenance fishing.\21\
---------------------------------------------------------------------------

    \21\ In addition, for certain waters in the Southern Tribes' 
reservations, EPA also approved a sustenance fishing designated use 
specified in MIA.

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

[[Page 23245]]

    EPA's analysis of the settlement acts also led EPA to consider the 
tribes to be the general target population in their waters. 
Accordingly, EPA applied the 2000 Methodology's recommendations on 
exposure and cancer risk for the general target population in its 
evaluation of whether Maine's HHC protect the sustenance fishing use in 
waters in Indian lands. In other words, EPA considered whether the FCR 
reflected, as accurately as possible, the tribes' sustenance level FCR, 
and whether the CRL was protective of the sustenance fishers as a 
general population rather than as a highly exposed subpopulation. As 
explained in the February 2, 2015 disapproval decision, EPA concluded 
that the FCRs on which Maine's HHC are based \22\ do not result in 
criteria that ensure protection of the sustenance designated use for 
waters in Indian lands. This is because Maine's FCRs do not reflect the 
best available information regarding the tribes' sustenance level of 
consumption unsuppressed by pollutant concerns, which EPA determined in 
its scientific and policy judgment was necessary and appropriate in 
developing criteria to protect the sustenance fishing designated use of 
waters in Indian lands as required by the CWA. EPA also concluded, as 
explained in the March 16, 2015 decision, that Maine's 10-4 
CRL for arsenic does not adequately protect the general target 
population of tribal sustenance fishers in waters in Indian lands. (EPA 
approved a separate provision in Maine's regulations that requires that 
HHC be based on a CRL of 10-6, finding that it is consistent 
with EPA's 2000 Methodology and adequately protects tribal sustenance 
fishers as a general target population.)
---------------------------------------------------------------------------

    \22\ Maine's FCR for all toxic HHC except arsenic is 32.4 g/day, 
and for arsenic is 138 g/day.
---------------------------------------------------------------------------

    c. Criteria for Which EPA is Reserving Action. Although EPA 
disapproved Maine's criteria for arsenic, dioxin, and thallium for 
waters in Indian lands, there is some uncertainty regarding aspects of 
the science upon which EPA's 304(a) HHC are based such that EPA is 
deferring proposal of these criteria at this time. EPA did not update 
the 304(a) HHC for these three pollutants in 2015. For thallium, EPA's 
IRIS database does not currently contain a quantitative RfD 
assessment.\23\ For dioxin, IRIS does not currently contain a 
quantitative carcinogenicity assessment.\24\
---------------------------------------------------------------------------

    \23\ http://cfpub.epa.gov/ncea/iris/index.cfm?fuseaction=iris.showQuickView&substance_nmbr=1012.
    \24\ http://cfpub.epa.gov/ncea/iris/index.cfm?fuseaction=iris.showQuickView&substance_nmbr=1024.
---------------------------------------------------------------------------

    While EPA disapproved Maine's arsenic criteria for waters in Indian 
lands because the cancer risk level and fish consumption rate together 
did not provide a sufficient level of protection of the sustenance 
fishing use, EPA recognizes that there is substantial uncertainty 
surrounding the toxicological assessment of arsenic with respect to 
human health effects. EPA's current plan for addressing these issues is 
described in the Assessment Development Plan for the Integrated Risk 
Information System (IRIS) Toxicological Review of Inorganic Arsenic 
(EPA/630/R-14/101 November 2015). During a similar period of 
uncertainty surrounding the toxicological assessment of arsenic in 
2000, EPA similarly did not promulgate arsenic HHC for the State of 
California.\25\
---------------------------------------------------------------------------

    \25\ Federal Register Vol. 65, No. 97, Thursday, May 18, 2000, 
Rules and Regulations.
---------------------------------------------------------------------------

    Without specific numeric criteria in place for arsenic, thallium, 
and dioxin in waters in Indian lands, Maine is in a position to rely on 
the latest science and policy as it becomes available to interpret the 
existing narrative water quality criteria for waters in Indian lands. 
For example, permitting authorities in Maine should rely on existing 
narrative water quality criteria to establish effluent limitations as 
necessary for arsenic, thallium, and dioxin. Federal regulations at 40 
CFR 122.44(d)(1)(vi) describe options available to the state for this 
purpose. Unless Maine submits and EPA approves these criteria, EPA 
plans to propose criteria for thallium, dioxin, and arsenic for waters 
in Indian lands and any waters that are covered by the determination 
set forth in section III once it has updated the 304(a) HHC.
    d. What is EPA Proposing? EPA proposes HHC for 96 \26\ of the toxic 
pollutants applicable to waters in Indian lands that EPA disapproved. 
Table 3 provides the criteria proposed for each pollutant as well as 
the HHC inputs used to derive each one, as discussed below. These 
proposed criteria also apply to any waters that are covered by the 
determination set forth in section III.
---------------------------------------------------------------------------

    \26\ After further consideration, by letter of January 19, 2016, 
EPA withdrew its February 2, 2015 disapprovals of Maine's HHC for 
six pollutants (copper, asbestos, barium, iron, manganese and 
nitrates) and instead approved them. EPA concluded that those 
criteria were not calculated using a fish consumption rate, and 
therefore the basis for EPA's disapprovals of the HHC in the 
February 2, 2015 decision letter did not apply. EPA approved them as 
being consistent with EPA's recommended 304(a) criteria. In 
addition, EPA has withdrawn its February 2, 2015 disapprovals of 
Maine's HHC for the following HHC and instead approved them: (1) For 
the consumption of water plus organisms for 1,2-dichloropropane, 
1,4-dichlorobenzene, dichlorobromomethane, chlorodibromomethane, 
chrysene, methylene chloride, chlorophenoxy herbicide (2, 4, 5-TP), 
chlorophenoxy herbicide (2,4-D), and N-nitrosopyrrolidine; (2) for 
the consumption of organisms alone for acrolein and gamma-BHC 
(Lindane); and (3) for both the consumption of water plus organisms 
and for the consumption of organisms alone for 1,2-dichloroethane, 
acrylonitrile, benzidine, bis(chloromethyl) ether, chloroform, 
methyl bromide, and tetrachloroethylene. EPA calculated the HHC for 
these pollutants using the best science reflected in the 2015 
criteria updates (which were finalized after the disapprovals), 
along with a FCR of 286 to protect the sustenance fishing use, and 
concluded that the resulting HHC were either the same or less 
stringent than Maine's HHC that EPA had disapproved. Accordingly, 
EPA withdrew the disapprovals and approved these HHC based on their 
being adequate to protect the sustenance fishing use.
---------------------------------------------------------------------------

    i. Maine-Specific HHC Inputs--1. Fish Consumption Rate. In EPA's 
February 2, 2015 decision and in this proposal, EPA treats the tribes 
as the target general population for waters in Indian lands. EPA 
proposes this approach because EPA has determined that sustenance 
fishing is the applicable designated use for waters in Indian lands 
based on EPA's interpretation of Maine's designated use of ``fishing,'' 
and, for fresh waters in the Southern Tribes' reservations, also based 
on EPA's approval of section 6207(4) and (9) of MIA as a sustenance 
fishing designated use. Therefore, the criteria must protect that use. 
As discussed at length in EPA's February 2015 decision on Maine's WQS, 
these Indian lands and their associated waters have been specifically 
set aside for the Maine tribes to exercise their sustenance practices. 
These waters are at the core of the resource base provided for under 
the settlement acts to support these tribes as sustenance cultures.\27\ 
Having found that sustenance fishing is a designated use in the waters 
in Indian lands, it is reasonable for EPA to target tribal sustenance 
fishers as the general population for the purpose of establishing 
criteria to protect that use. The same analysis applies to waters 
outside of Indian lands where the sustenance fishing designated use 
applies.
---------------------------------------------------------------------------

    \27\ EPA recognizes that the general public has the right to 
access some tribal waters and to fish there subject to conditions 
that do not discriminate between tribal members and non-members. See 
MIA Sec.  6207(1).
---------------------------------------------------------------------------

    EPA derived the HHC to protect the sustenance fishing use based on 
a total fish consumption rate (FCR) of 286 g/day. EPA selected this 
consumption rate based on information contained in an historical/
anthropological study, entitled the Wabanaki Cultural Lifeways

[[Page 23246]]

Exposure Scenario \28\ (``Wabanaki Study''), which was completed in 
2009. EPA also consulted with the tribes in Maine about the Wabanaki 
Study and their sustenance fishing uses of the waters in Indian lands. 
There has been no contemporary local survey of current fish 
consumption, adjusted to account for suppression, that documents fish 
consumption rates for sustenance fishing in the waters in Indian lands 
in Maine. In the absence of such information, EPA concluded that the 
Wabanaki Study contains the best currently available information for 
the purpose of deriving an unsuppressed FCR for HHC adequate to protect 
sustenance fishing for such waters.
---------------------------------------------------------------------------

    \28\ Harper, B., Ranco, D., et al. 2009. Wabanaki Traditional 
Cultural Lifeways Exposure Scenario. http://www.epa.gov/sites/production/files/2015-08/documents/ditca.pdf.
---------------------------------------------------------------------------

    The peer-reviewed Wabanaki Study was produced under a Direct 
Implementation Tribal Cooperative Agreement (DITCA) awarded by EPA to 
the Aroostook Band of Micmac Indians on behalf of all of the Maine 
tribes. The purpose of the Study was to use available anthropological 
and ecological data to develop a description of Maine tribes' 
traditional cultural uses of natural resources, and to present the 
information in a format that could be used by EPA to evaluate whether 
or not tribal uses are protected when EPA reviews or develops WQS in 
Indian lands in Maine. It is relevant to contemporary water quality 
because another purpose of the Study ``is to describe the lifestyle 
that was universal when resources were in better condition and that 
some tribal members practice today (and many more that are waiting to 
resume once restoration goals and protective standards are in place).'' 
It provides a numerical representation of the environmental contact, 
diet, and exposure pathways of the traditional tribal lifestyle, 
including the use of water resources for food, medicine, cultural and 
traditional practices, and recreation. The report used anthropological 
and ecological data to identify major activities that contribute to 
environmental exposure and then to develop exposure factors related to 
traditional diet, drinking water, soil and sediment ingestion, 
inhalation rate and dermal exposure. Credible ethno-historical, 
ecological, nutritional, archaeological, and biomedical literature was 
reviewed through the lens of natural resource use and activities 
necessary to survive in the Maine environment and support tribal 
traditions. Along with single, best professional judgment estimates for 
direct exposures (inhalation, soil ingestion, water ingestion) as a 
reasonable representation (central tendency) of the traditional 
cultural lifeways, the Wabanaki Study provides an estimated range of 
diets that reflect three major habitat types.
    In developing the dietary component of the exposure scenario, the 
Wabanaki Study authors assembled information about general foraging, 
seasonal patterns, dietary breadth, abundance, and food storage. From 
these they evaluated the relative proportion of major food groups, 
including fish, as well as nutritional information, total calories and 
quantities of foods. This resulted in an estimate of a nutritionally 
complete diet for the area east of the Kennebec River, which is the 
area most heavily used by tribal members today and where farming is 
marginal due to climate. With regard to the consumption of fish, the 
Wabanaki Study identifies three traditional lifestyle models, each with 
its own diet:
    1. Permanent inland residence on a river with anadromous fish runs 
(``inland anadromous''),
    2. Permanent inland residence with resident fish only (``inland 
non-anadromous''), and
    3. Permanent coastal residence (``coastal'').
    The study provides estimates of average adult consumption of 
aquatic resources, game, fowl, and plant-based foods for each lifestyle 
model based on a 2,000 kcal/day diet. Aquatic resources were divided 
into two categories: ``resident fish and other aquatic resources'' and 
``anadromous and marine fish and shellfish.'' Table 2 summarizes the 
consumption of aquatic resources for each lifestyle model.

                        Table 2--Consumption of Aquatic Resources by Lifestyle Model \29\
----------------------------------------------------------------------------------------------------------------
                                                                   Resident fish
                                                                      & other      Anadromous &
                         Lifestyle model                              aquatic      marine fish,        Total
                                                                   resources (g/  shellfish  (g/
                                                                       day)          day) \30\
----------------------------------------------------------------------------------------------------------------
Inland Anadromous...............................................             114             400             514
Inland Non-anadromous...........................................             286               0             286
Coastal.........................................................              57             457             514
----------------------------------------------------------------------------------------------------------------

    The Wabanaki Study provides a range of consumption rates 
specifically for Maine Indians using natural resources for sustenance 
living and reduces the uncertainties associated with a lack of 
knowledge about tribal exposure in Maine Indian waters.
---------------------------------------------------------------------------

    \29\ Id., pp. 61-66.
    \30\ Includes marine mammals for coastal lifestyle model only.
---------------------------------------------------------------------------

    In addition to evaluating the Wabanaki Study, EPA consulted with 
the four Maine tribes to gather additional information about current 
practices, present day circumstances related to the species composition 
of available fish, and any other information that the tribes thought 
was relevant to EPA's decision making. EPA also considered the 
Penobscot Nation's use of a FCR of 286 g/day in developing HHC in its 
2014 tribal WQS. In its September 23, 2014 responses to comments on the 
final WQS, the Nation explained that it chose the inland non-anadromous 
total FCR of 286 g/day because, although the Penobscot lands are in 
areas that would have historically supported an inland anadromous diet 
(with a total FCR of 514 g/day), the contemporary populations of 
anadromous species in Penobscot waters are currently too low to be 
harvested in significant quantities. The Nation's representative 
reiterated this rationale in the September 9, 2015 tribal consultation 
with EPA. The representative of the Aroostook Band of Micmacs also 
stated during the consultation that the Wabanki Study's inland non-
anadromous lifestyle diet reflects the current Micmac diet, although 
the tribe has a goal of the return and consumption of anadromous fish.
    EPA proposes to use a FCR of 286 g/day to represent present day 
sustenance-level fish consumption, unsuppressed

[[Page 23247]]

by pollution concerns, in the waters covered by this action. This value 
reflects the Wabanaki Study's 286 g/day FCR for the inland non-
anadromous lifestyle, which relied on resident fish species only. For 
tribes that followed the inland anadromous lifestyle, 286 g/day 
represents all of the resident species fish consumption rate (114 g/
day) as well as approximately 43% of the 400 g/day consumption rate for 
anadromous and other non-resident species (172 g/day). For tribes that 
followed the coastal lifestyle, 286 g/day represents all of the 
resident species fish consumption rate (57 g/day) as well as 
approximately 50% of the 457 g/day consumption rate for anadromous and 
other non-resident species (229 g/day). It is reasonable to assume that 
the inland anadromous and coastal lifestyle tribes would have shifted a 
substantial percentage of the sustenance fishing diet from the formerly 
widely available but now less available anadromous species (such as 
salmon) or protected marine mammals to resident fish species, including 
introduced freshwater species, corresponding to the FCR for the inland 
non-anadromous lifestyle. That assumption is consistent with the 
Penobscot Nation's approach to deriving a current, unsuppressed FCR to 
protect sustenance fishing.
    Since the Wabanaki Study presented estimates of the total amount of 
fish and aquatic organisms consumed and not the amount consumed of each 
trophic level, for the purpose of developing HHC for the Maine tribes, 
EPA assumes that Maine tribes consume the same relative proportion of 
fish and aquatic organisms from the different trophic levels 2 through 
4 as the general U.S. population, as identified in the 2015 criteria 
update (i.e., 36%, 40%, and 24% of the total amount consumed for 
trophic levels 2, 3, and 4, respectively). Accordingly, EPA proposes to 
use trophic-specific fish consumption rates of 103 g/day (trophic level 
2), 114 g/day (trophic level 3), and 68.6 g/day (trophic level 4) for 
the HHC for those compounds which the 2015 criteria update included 
trophic level specific BAFs.
    2. Pollutant Bioaccumulation and Bioconcentration Factors. In order 
to prevent harmful exposures to waterborne chemicals through the 
consumption of contaminated fish and shellfish, HHC must address the 
process of chemical bioaccumulation in aquatic organisms. For the 2015 
criteria update, EPA estimated chemical-specific BAFs for three 
different trophic levels of fish (levels 2 through 4), using a 
framework for deriving national BAFs described in EPA's 2000 
Methodology.\31\ EPA proposes to use those BAFs to calculate the 
proposed HHC.
---------------------------------------------------------------------------

    \31\ USEPA. 2000. Methodology for Deriving Ambient Water Quality 
Criteria for the Protection of Human Health. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC. EPA-822-B-00-
004. http://www.epa.gov/waterscience/criteria/humanhealth/method/complete.pdf.
---------------------------------------------------------------------------

    Where EPA did not update BAFs for certain pollutants in the 2015 
criteria update, and for cyanide, EPA proposes HHC using the BCFs 
(which are not trophic-level specific) that the Agency used the last 
time it updated its 304(a) HHC for those pollutants as the best 
available scientific information.
    3. Cancer Risk Level. Maine's water quality regulations, at Maine's 
Department of Environmental Protection (DEP) Rule Chapter 584 section 
4, specify that water quality criteria for carcinogens must be based on 
a CRL of 10-6 (except for a 10-4 CRL for arsenic, 
which EPA disapproved). On February 2, 2015, EPA approved the 
10-6 CRL for waters in Indian lands, since it is consistent 
with the range of CRLs that EPA considers to be appropriate for the 
general population. This is also the risk level that EPA uses when 
publishing its 304(a) HHC and when promulgating federal criteria.\32\ 
As explained above, EPA considers the tribes to be the general target 
population for waters in Indian lands. For these reasons, EPA proposes 
to use a 10-6 CRL in its criteria for carcinogens for waters 
covered by this action.
---------------------------------------------------------------------------

    \32\ USEPA. 2000. Methodology for Deriving Ambient Water Quality 
Criteria for the Protection of Human Health. US Environmental 
Protection Agency. pp. 2-6.
---------------------------------------------------------------------------

    4. Relative Source Contribution. EPA recommends using a RSC for 
non-carcinogens and nonlinear carcinogens to account for sources of 
exposure other than drinking water and consumption of inland and 
nearshore fish and shellfish (see 2015 criteria update, section 
II.B.d).\33\ In 2015, after evaluating information on chemical uses, 
properties, occurrences, releases to the environment and regulatory 
restrictions, EPA developed chemical-specific RSCs for non-carcinogens 
and nonlinear carcinogens ranging from 0.2 (20%) to 0.8 (80%) following 
the Exposure Decision Tree approach described in EPA's 2000 Methodology 
and used them in the 2015 criteria updates.34 35 For these 
pollutants, EPA proposes to use the same RSCs to derive the HHC. For 
pollutants where EPA did not update the 304(a) HHC in 2015, EPA 
proposes to use a default RSC of 0.2 to derive HHC following the 
Exposure Decision Tree approach described in EPA's 2000 Methodology; a 
RSC of 0.2 is used as a default RSC when EPA has not developed a 
pollutant-specific RSC based on exposure/occurrence data. In the case 
of antimony (for which EPA did not update the 304(a) HHC in 2015), EPA 
proposes to use an RSC of 0.4 consistent with the RSC value used the 
last time the Agency updated this criterion.\36\
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    \33\ Final Updated Ambient Water Quality Criteria for the 
Protection of Human Health, (80 FR 36986, June 29, 2015). See also: 
USEPA. 2015. Final 2015 Updated National Recommended Human Health 
Criteria. U.S. Environmental Protection Agency, Office of Water, 
Washington, DC. http://water.epa.gov/scitech/swguidance/standards/criteria/current/hhfinal.cfm.
    \34\ USEPA. 2000. Methodology for Deriving Ambient Water Quality 
Criteria for the Protection of Human Health. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC. EPA-822-B-00-
004. http://www.epa.gov/waterscience/criteria/humanhealth/method/complete.pdf.
    \35\ Final Updated Ambient Water Quality Criteria for the 
Protection of Human Health, (80 FR 36986, June 29, 2015). See also: 
USEPA. 2015. Final 2015 Updated National Recommended Human Health 
Criteria. U.S. Environmental Protection Agency, Office of Water, 
Washington, DC. http://water.epa.gov/scitech/swguidance/standards/criteria/current/hhfinal.cfm.
    \36\ USEPA. 2002. National Recommended Water Quality Criteria: 
2002 Human Health Criteria Calculation Matrix. EPA-822-R-02-012. 
U.S. Environmental Protection Agency, Office of Water, Washington, 
DC. http://water.epa.gov/scitech/swguidance/standards/upload/2002_12_30_criteria_wqctable_hh_calc_matrix.pdf.
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    5. Body Weight. EPA proposes to calculate HHC using a body weight 
of 80.0 kg, which represents the average weight of a U.S. adult. In 
2015, EPA updated its recommended adult body weight to 80.0 kg based on 
national survey data (see 2015 criteria update, section II.B.c).\37\ 
EPA is not aware of any local body weight data applicable to Maine 
tribes that would suggest a different value.
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    \37\ Final Updated Ambient Water Quality Criteria for the 
Protection of Human Health, (80 FR 36986, June 29, 2015). See also: 
USEPA. 2015. Final 2015 Updated National Recommended Human Health 
Criteria. U.S. Environmental Protection Agency, Office of Water, 
Washington, DC. http://water.epa.gov/scitech/swguidance/standards/criteria/current/hhfinal.cfm.
---------------------------------------------------------------------------

    6. Drinking Water Intake. EPA proposes to calculate HHC using a 
drinking water intake rate of 2.4 L/day. In 2015, EPA updated its 
national default drinking water intake rate in the 304(a) HHC to 2.4 L/
day (see 2015 criteria update, section II.B.c).\38\ This rate is based 
on the national survey data and represents the per capita estimate of 
combined direct and indirect community water ingestion at the 90th

[[Page 23248]]

percentile for adults ages 21 and older. EPA is not aware of any local 
data applicable to Maine tribes that suggest a different rate.
---------------------------------------------------------------------------

    \38\ Final Updated Ambient Water Quality Criteria for the 
Protection of Human Health, (80 FR 36986, June 29, 2015). See also: 
USEPA. 2015. Final 2015 Updated National Recommended Human Health 
Criteria. U.S. Environmental Protection Agency, Office of Water, 
Washington, DC. http://water.epa.gov/scitech/swguidance/standards/criteria/current/hhfinal.cfm.
---------------------------------------------------------------------------

    7. Pollutant-Specific Reference Doses and Cancer Slope Factors. As 
part of EPA's 2015 criteria update, EPA conducted a systematic search 
of eight peer-reviewed, publicly available sources to obtain the most 
current toxicity values for each pollutant (RfDs for non-carcinogenic 
effects and CSFs for carcinogenic effects).\39\ EPA proposes to 
calculate HHC using the same toxicity values that EPA used in its 2015 
criteria update, to ensure that the resulting criteria are based on a 
sound scientific rationale. Where EPA did not update criteria for 
certain pollutants in 2015, EPA proposes to use the toxicity values 
that the Agency used the last time it updated its 304(a) HHC for those 
pollutants.
---------------------------------------------------------------------------

    \39\ Final Updated Ambient Water Quality Criteria for the 
Protection of Human Health, (80 FR 36986, June 29, 2015). See also: 
USEPA. 2015. Final 2015 Updated National Recommended Human Health 
Criteria. U.S. Environmental Protection Agency, Office of Water, 
Washington, DC. http://water.epa.gov/scitech/swguidance/standards/criteria/current/hhfinal.cfm.
---------------------------------------------------------------------------

    ii. Proposed Criteria. EPA proposes HHC for 96 different pollutants 
(93 organism-only criteria, 88 water-plus-organism criteria) to protect 
the sustenance fishing designated use in the waters covered by this 
action (see Table 3). In accordance with Maine DEP Rule Chapter 584, 
paragraph 1, the proposed ``Water & Organisms'' criteria would apply to 
all waters except for marine waters, where the proposed ``Organisms 
Only'' criteria would apply.
    All of the proposed HHC criteria are proposed in units of 
micrograms per liter ([micro]g/L) except for methylmercury,\40\ which 
is expressed as mg/kg in the edible portion of fish.
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    \40\ EPA proposes a fish tissue-based methylmercury criterion 
rather than a fish tissue-based mercury criterion (which EPA 
disapproved in Indian waters) because methylmercury is the form of 
mercury found in fish and to which humans are exposed through eating 
fish. Human exposure to other forms of mercury is typically not 
associated with the aquatic environment.
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B. Proposed WQS for Waters in Indian Lands

1. Bacteria Criteria
    a. What did EPA disapprove? On March 16, 2015, EPA disapproved 
Maine's 1985 bacteria criteria for the protection of the designated use 
of ``recreation in and on the water'' (recreational criteria), as 
revised in 2005 and 2008, for Class B, C, GPA, SB and SC waters in 
Indian lands. This designated use and these criteria are set forth in 
38 M.R.S. 465(3.B) and (4.B), 465-A(1.B), and 465-B(2.B) and (3.B), 
respectively. EPA's disapproval of Maine's recreational criteria for 
waters in Indian lands was based on a review of whether the criteria, 
as a whole, protect the applicable designated use. Because Maine's 
recreational criteria apply only to fecal sources of human and domestic 
origin and do not include an explicit duration and frequency of 
exceedance, EPA concluded that Maine's recreational criteria are not 
fully protective of the recreation designated use in waters in Indian 
lands.
    Maine's recreational bacteria criteria for Class B, C, GPA, SB and 
SC waters include only fecal sources of ``human and domestic origin'' 
and fail to include naturally occurring sources. In the case of 
bacteria, pathogens that pose human health risks can come from 
naturally occurring sources such as wildlife as well as from human and 
domestic sources. Therefore, a potential human health risk from 
recreational exposure to bacteria exists in wildlife-impacted waters 
(2012 Recreational Water Quality Criteria, section 3.5.1-2). In 
addition, EPA published new recommended 304(a) recreational criteria in 
2012, which include two numeric thresholds (geometric mean and 
statistical threshold value, or STV), an averaging duration, and a 
maximum frequency of exceedance. Maine's recreational criteria do not 
include an explicit duration and frequency of exceedance or an STV, all 
of which EPA finds are necessary to protect designated uses.
    On June 5, 2015, EPA disapproved the narrative bacteria criteria 
for Class AA, A and SA waters in Indian lands for the protection of 
recreation uses and, in the case of SA waters, also for shellfishing 
uses. These criteria are set forth in 38 M.R.S. 465(1.B and 2.B) and 
465-B(1.B), respectively. These criteria specify that the bacteria 
content of these waters shall be ``as naturally occurs.'' Although the 
intent of these criteria is to reflect conditions unaffected by human 
activity, in the case of bacteria, pathogens that pose human health 
risks from recreational exposure or shellfish consumption can result 
from naturally occurring sources such as wildlife. Because these 
narrative bacteria criteria do not address bacteria from wildlife 
sources, EPA disapproved them as not adequately protecting recreation 
in and on the waters in Class AA, A and SA waters, and propagation and 
harvesting of shellfish in Class SA waters.
    b. What is EPA proposing? i. Recreational Bacteria Criteria. EPA is 
proposing recreational criteria for Class AA, A, B, C, GPA, SA, SB and 
SC waters in Indian lands based on EPA's 2012 Recreational Water 
Quality Criteria (RWQC) recommendations (EPA Office of Water 820-F-12-
058). The criterion magnitude is expressed in terms of Escherichia coli 
colony forming units per 100 milliliters (cfu/100 ml) for fresh waters 
and Enterococcus spp. colony forming units per 100 milliliters (cfu/100 
ml) for marine waters, consistent with Maine's current criteria 
expression and EPA's 2012 recommendations.
    The 2012 RWQC recommendations offer two sets of numeric 
concentration thresholds, either of which would protect the designated 
use of primary contact recreation and, therefore, would protect the 
public from exposure to harmful levels of pathogens. The proposed 
criteria's magnitude, duration and frequency are based on EPA's illness 
rate of 32 NGI per 1,000 primary contact recreators, where NGI 
represents the gastrointestinal illnesses as measured by EPA's National 
Epidemiological and Environmental Assessment of Recreational Water 
(NEEAR) study.\41\ EPA chose the 32 NGI per 1,000 primary contact 
recreators illness rate because the resulting geometric mean components 
of the criteria most closely match the geometric means in Maine's 
criteria. EPA specifically invites comment on whether instead to base 
the criteria on EPA's alternative illness threshold of 36 NGI per 1,000 
primary contact recreators set forth in the 2012 RWQC.
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    \41\ USEPA. 2010. Report on 2009 National Epidemiologic and 
Environmental Assessment of Recreational Water Epidemiology Studies. 
United States Environmental Protection Agency, Washington, DC EPA-
600-R-10-168.
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    In addition, for Class AA, A and SA waters in Indian lands, EPA is 
proposing to include Maine's narrative criteria expression that 
bacteria content of these waters be no greater than as ``naturally 
occurs.'' This maintains Maine's intention that the waters be free of 
human caused pathogens, while the specific numeric criteria EPA 
proposes also provide protection for designated recreational uses in 
the event there are wildlife sources.
    Finally, in accordance with the recommendation to Maine in EPA's 
March 16, 2015 letter, EPA is proposing that the criteria apply all 
year long in all waters in Indian lands. This differs from Maine's 
disapproved criteria, which do not apply from October 1 through May 14 
in Classes B, C, GPA, SB, and SC waters. EPA does not have a record to 
support a conclusion that no recreation in and on these waters occurs 
between October 1 and May 14. On the contrary, EPA has found 
information indicating that white water rafting, paddling, and kayaking 
occur after October 1,\42\ and during consultation EPA learned from the 
Penobscot Nation that as long as there is no ice on the Penobscot 
River, recreators are on the river paddling and fishing. At the same 
time, EPA recognizes that there may be periods during which 
recreational activities do not occur in and on these waters. Therefore, 
EPA specifically invites comment on whether EPA should promulgate an 
alternative seasonal term during which the criteria would not apply 
that would adequately protect recreational uses, such as, for example, 
December through February.
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    \42\ http://www.penobscotadventures.com/online-booking/ 
(whitewater rafting on Penobscot River Oct. 2-4, 2015); http://www.paddleandchowder.org/ (paddling/kayaking in October)
---------------------------------------------------------------------------

    ii. Shellfishing Bacteria Criteria. EPA proposes shellfishing 
criteria for SA waters in Indian lands based on recommendations from 
the National Shellfish Sanitation Program (NSSP). The criteria 
magnitude is expressed in terms of total coliform Most Probable Number 
(MPN)/100 ml.
    EPA last provided recommendations for bacteria to protect shellfish 
harvesting uses in its 1986 304(a) recommendations,\43\ which provided 
fecal coliform criteria for shellfish harvesting. As described in that 
document, the basis for the criteria was a study from the NSSP which 
related an accepted international standard of total coliforms to fecal 
coliforms. NSSP has published several versions of its guidance which 
provides recommendations for criteria expressed as fecal coliform or 
total coliform. EPA proposes to promulgate criteria as total coliform 
to be consistent with Maine's narrative criteria to protect shellfish 
harvesting in Class SB and SC waters, which say that the numbers of 
total coliform bacteria or other specified indicator organisms in 
samples representative of the waters in Class SB and SC shellfish 
harvesting areas may not exceed criteria recommended under

[[Page 23255]]

the National Shellfish Sanitation Program, United States Food and Drug 
Administration.
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    \43\ USEPA. 1986. Quality Criteria for Water 1986, United States 
Environmental Protection Agency, Washington, DC. EPA 440/5-86-001.
---------------------------------------------------------------------------

    EPA proposes that in Class SA shellfish harvesting areas, the 
number of total coliform bacteria in samples representative of the 
waters in shellfish harvesting areas shall not exceed a geometric mean 
for each sampling station of 70 MPN (most probable number) per 100 ml, 
with not more than 10% of samples exceeding 230 MPN per 100 ml for the 
taking of shellfish. The proposal is consistent with the current NSSP 
recommendations for total coliform included in the ``Standard for the 
Approved Growing Area Classification in the Remote Status.'' \44\ 
Therefore, the proposed criteria are protective of shellfish harvesting 
uses in Class SA waters.
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    \44\ USDA. 2013. National Shellfish Sanitation Program (NSSP) 
Guide for the Control of Molluscan Shellfish: 2013 Revision. United 
States Food and Drug Administration, Washington, DC page 210. posted 
at http://www.fda.gov/downloads/Food/GuidanceRegulation/FederalStateFoodPrograms/UCM415522.pdf
---------------------------------------------------------------------------

    2. Ammonia Criteria for Fresh Waters. a. What did EPA disapprove? 
On March 16, 2015, EPA disapproved the ammonia criteria for protection 
of aquatic life for fresh waters in Indian lands. The criteria are set 
forth in DEP Rule Chapter 584, Appendix A. EPA's disapproval was based 
on a review of whether the criteria protect the applicable designated 
uses and are based on sound scientific rationale. EPA revised its CWA 
Section 304(a) recommended ammonia criteria for fresh waters in August 
2013 and incorporated the latest science for freshwater mussels and 
snails, which are sensitive to ammonia toxicity.\45\ This science was 
not included in EPA's 1999 ammonia criteria recommendations, on which 
Maine's criteria are based. Therefore, EPA concluded that Maine's 
criteria are not protective of the designated use because they are not 
protective of freshwater mussels and snails and, accordingly, 
disapproved the criteria.
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    \45\ USEPA. 2013. Aquatic Life Ambient Water Quality Criteria 
for Ammonia--Freshwater 2013. United States Environmental Protection 
Agency, Washington, DC EPA 822-R-13-001
---------------------------------------------------------------------------

    b. What is EPA proposing? Ammonia is a constituent of nitrogen 
pollution. Unlike other forms of nitrogen, which can cause 
eutrophication of a waterbody at elevated concentrations, the primary 
concern with ammonia is its direct toxic effects on aquatic life, which 
are exacerbated by elevated pH and temperature.
    EPA proposes ammonia criteria for fresh waters in Indian lands 
based on the 2013 updated 304(a) recommended ammonia criterion. The 
acute and chronic criteria concentrations in EPA's 2013 update are 
expressed as functions of temperature and pH, so the applicable 
criteria vary by waterbody, depending on the temperature and pH of 
those waters. The criteria document describes the relationship between 
ammonia and these water quality factors and provides tables showing how 
the criteria values change with varying pH and temperatures. EPA's 
proposed criteria include tables that contain Criterion Maximum 
Concentrations (CMC) and Criterion Continuous Concentrations (CCC) that 
correspond to a range of temperatures and pH values, and require that 
the applicable CMCs and CCCs shall not be exceeded. In addition, 
consistent with EPA's recommended criteria, the proposed criteria 
include a requirement that the highest four-day average within the same 
30-day period used to determine compliance with the CCC shall not 
exceed 2.5 times the CCC, more than once every three years. For the 
reasons explained in EPA's 304(a) criteria recommendations for ammonia, 
EPA's proposed criteria are protective of the designated aquatic life 
use and based on sound science.
    3. pH Criterion for Fresh Waters. a. What did EPA disapprove? 
Maine's freshwater pH criterion in 38 M.R.S. 464(4.A(5)) prohibits 
discharges from causing the pH of receiving waters to fall outside the 
range of 6.0 to 8.5. On June 5, 2015, EPA disapproved the pH criterion 
for fresh waters in Indian lands because the lower end of the range 
(6.0) is not protective of aquatic life uses.
    b. What is EPA proposing? EPA proposes a pH criterion with a range 
of 6.5 to 8.5. The proposal is based on the lower value of EPA's 
recommended pH criterion (6.5 to 9.0) \46\ to protect freshwater fish 
and bottom-dwelling invertebrates that provide food for freshwater 
fish. In waters that are more acidic than 6.5, the likelihood of harm 
to aquatic species increases when periodic acidic inputs (either 
natural or anthropogenic in origin) liberate CO2 from 
bicarbonate in the water leading to direct lethality as a result of 
lack of oxygen, or causing a further drop in pH into potentially lethal 
ranges. Fish suffer adverse physiological effects increasing in 
severity as the degree of acidification increases, until lethal levels 
are reached. Therefore, EPA proposes that the pH of fresh waters in 
Indian lands in Maine shall not fall below 6.5. EPA includes in the 
proposal Maine's existing value of 8.5 for the upper end of the pH 
range because it is within the range of 6.5 to 9.0 that EPA recommends 
in order to protect aquatic species from extreme pH conditions.
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    \46\ USEPA. 1986. Quality Criteria for Water 1986, United States 
Environmental Protection Agency, Washington, DC. EPA 440/5-86-001, 
pH section.
---------------------------------------------------------------------------

    4. Temperature Criteria for Tidal Waters. a. What did EPA 
disapprove? On June 5, 2015, EPA disapproved Maine's tidal temperature 
criteria in DEP Rule Chapter 582(5), for tidal waters in Indian lands 
(specifically, the intertidal zone at Pleasant Point), because they are 
not protective of aquatic life uses. The criteria allow a 4 [deg]F 
monthly average rise in ambient temperatures from individual 
dischargers from September 2 to May 30, and a 1.5 [deg]F monthly 
average rise from June 1 to September 1, as measured outside of any 
mixing zone; they also allow a maximum temperature of 85 [deg]F as 
measured outside of any mixing zone. EPA disapproved the 4 [deg]F 
temperature rise provision and the maximum temperature criterion of 85 
[deg]F as not protective of indigenous species that have been 
associated with tidal waters in the vicinity of Pleasant Point, where 
typical temperatures are in the 37 [deg]-52 [deg]F range based on the 
nearest NOAA monitoring station at Eastport, Maine.
    b. What is EPA proposing? In order to assure protection of the 
indigenous marine community characteristic of the intertidal zone at 
Pleasant Point, EPA proposes criteria consistent with EPA's 304(a) 
recommended criteria for tidal waters.\47\ EPA proposes a maximum 
increase in the weekly average baseline ambient temperature resulting 
from artificial sources of 1 [deg]C (1.8 [deg]F) during all seasons of 
the year, provided that the summer maximum of 18 [deg]C (64.4 [deg]F) 
is not exceeded. The proposal specifies that the weekly average 
baseline thermal condition must be calculated using the daily maxima 
averaged over a 7-day period, and must be measured at a reference site 
where there is no unnatural thermal addition from any source, that is 
in reasonable proximity to the thermal discharge (within five miles), 
and that has similar hydrography to that of the receiving waters at the 
discharge. Further, EPA proposes that daily temperature cycles 
characteristic of the waterbody shall not be altered in either 
amplitude or frequency.\48\
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    \47\ USEPA. 1986. Quality Criteria for Water 1986, U.S. 
Environmental Protection Agency, Office of Water, Washington, DC. 
EPA 440/5-86-001. Temperature section.
    \48\ Id.
---------------------------------------------------------------------------

    The natural temperature fluctuation provision in the proposed rule 
is necessary to induce and protect the reproductive cycles of aquatic

[[Page 23256]]

organisms and to regulate other life factors. Since aquatic organisms 
are essentially poikilotherms (cold blooded), the temperature of the 
water regulates their metabolism and ability to survive and reproduce 
effectively. In addition, natural temperature fluctuations are 
essential to maintain the existing community structure and the 
geographic distribution of species.\49\
---------------------------------------------------------------------------

    \49\ Id,
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    In intertidal waters, elevated temperatures affect periphyton, 
benthic invertebrates, and fish, in addition to causing shifts in the 
dominant primary producers. Community balance can be influenced 
strongly by temperature-dependent factors, including: rates of 
reproduction, recruitment, and growth of each component population--all 
of which were considered in deriving all components of the temperature 
criteria in this rule. A few degrees elevation in average monthly 
temperature outside of the conditions described in this rule can 
appreciably alter a community through changes in interspecies 
relationships.\50\
---------------------------------------------------------------------------

    \50\ Id.
---------------------------------------------------------------------------

    The intertidal zone at Pleasant Point is home to indigenous species 
such as pollock, haddock, juvenile flounder, juvenile and adult shad, 
cod, alewife, blueback herring as well as various species of clams, 
crabs, urchins and lobsters found in the vicinity of these waters 
(personal communication Dr. Theo Willis, University of Southern Maine 
and Dr. Robert Stephenson, St. Andrews Biological Station, St. Andrews 
NB).
    Pollock are indigenous fish that inhabit the subtidal and 
intertidal zones of the Gulf of Maine.\51\ Within the subtidal and 
intertidal zones, pollock move to different locations depending on the 
temperature conditions.\52\ Pollock are abundant in the intertidal zone 
in the summer and fall months, and as such, are an appropriate 
sensitive, indigenous species by which to set a summer maximum 
temperature criterion.\53\ EPA proposes a summer weekly maximum of 18 
[deg]C (64.4 [deg]F), which is consistent with EPA's Gold Book 
methodology and is the value identified in the scientific literature 
that is protective of juvenile pollock (Pollachius virens).\54\
---------------------------------------------------------------------------

    \51\ Id.
    \52\ Id.
    \53\ Id.
    \54\ Cargnelli et al. National Oceanic and Atmospheric 
Administration. NOAA Technical Memorandum NMFS-NE-131. Essential 
Fish Habitat Source Document: Pollock, Pollachius virens, Life 
History and Habitat Characteristics. September 1999. Pages 1-38.
---------------------------------------------------------------------------

    The summer maximum of 18 [deg]C (64.4 [deg]F) is a weekly average 
value and is calculated using the daily maxima averaged over a 7-day 
period, similar to the calculation of the baseline ambient temperature. 
EPA uses a weekly average maximum temperature because, as explained in 
regional guidance, ``it describes the maximum temperatures . . . but is 
not overly influenced by the maximum temperature of a single day. Thus 
it reflects an average of maximum temperatures that fish are exposed to 
over a week-long period.'' \55\
---------------------------------------------------------------------------

    \55\ Id.
---------------------------------------------------------------------------

    Collectively, the criteria that EPA proposes will protect aquatic 
life from the deleterious effects of increased mean water temperature 
and from alterations in the amplitude and frequency of mean-high and 
mean-low water temperatures. EPA's recommended 304(a) criteria, on 
which this proposal is based, are designed to protect aquatic species 
from short- and long-term temperature anomalies, resulting in the 
maintenance of reproductive, recruitment, and growth cycles.
    5. Natural Conditions Provisions. a. What did EPA disapprove? On 
June 5, 2015, EPA disapproved, for waters in Indian lands, two natural 
conditions provisions as they apply to water quality criteria to 
protect human health. Specifically, EPA disapproved 38 M.R.S. 420(2.A), 
which states ``Except as naturally occurs or as provided in paragraphs 
B and C, the board shall regulate toxic substances in the surface 
waters of the State at the levels set forth in federal water quality 
criteria as established by the United States Environmental Protection 
Agency pursuant to the Federal Water Pollution Control Act, Public Law 
92-500, Section 304(a), as amended''; and 38 M.R.S. 464(4.C), which 
states: ``Where natural conditions, including, but not limited to, 
marshes, bogs and abnormal concentrations of wildlife cause the 
dissolved oxygen or other water quality criteria to fall below the 
minimum standards specified in sections 465, 465-A and 465-B, those 
waters shall not be considered to be failing to attain their 
classification because of those natural conditions.''
    EPA concluded that to the extent that these provisions would allow 
an exception from otherwise applicable HHC, they are not consistent 
with EPA's interpretation of the relationship between natural 
conditions and the protection of designated human health uses, which is 
articulated in EPA's November 5, 1997 guidance entitled ``Establishing 
Site Specific Aquatic Life Criteria Equal to Natural Background.'' \56\ 
In contrast with aquatic life uses,\57\ a naturally occurring level of 
a pollutant does not necessarily protect designated human health uses. 
Naturally occurring levels of a pollutant are assumed to protect 
aquatic life species that have naturally developed in the affected 
waters. However, human health does not adapt to higher ambient 
pollutant levels, even if they are naturally caused. Consequently, the 
same assumptions of protectiveness cannot be made with regard to 
designated uses that affect human health (e.g., people eating fish or 
shellfish from Maine waters, and recreating in Maine waters). For this 
reason, EPA's 1997 guidance also states that where the natural 
background concentration exceeds the state-adopted human health 
criterion, at a minimum, states should re-evaluate the human health use 
designation.
---------------------------------------------------------------------------

    \56\ Davies, Tudor T., Establishing Site Specific Aquatic Life 
Criteria Equal to Natural Background, EPA Memorandum to Water 
Management Division Directors, Regions 1-10, State and Tribal Water 
Quality Management Program Directors, posted at: http://www.epa.gov/sites/production/files/2014-08/documents/naturalbackground-memo.pdf
    \57\ EPA approved these natural conditions provisions for waters 
in Indian lands as they relate to aquatic life, acknowledging that 
there may be naturally occurring concentrations of pollutants that 
exceed the national criteria published under section 304(a) of the 
CWA that are still protective of aquatic life.
---------------------------------------------------------------------------

    EPA disapproved the natural conditions clauses at 38 M.R.S 464(4.C) 
and 420(2.A) for waters in Indian lands as they apply to criteria that 
protect human health because the application of these provisions fails 
to protect designated human health uses as required by the CWA and 
federal WQS regulations at 40 CFR 131.11(a).
    b. What is EPA proposing? For each of the disapproved naturally 
occurring or natural conditions exceptions, EPA proposes a regulation 
that states that such provision ``does not apply to water quality 
criteria intended to protect human health.'' Under this approach, Maine 
still could implement the natural conditions provisions for other 
criteria related to non-human health uses.
    6. Mixing Zone Policy. a. What did EPA disapprove? On June 5, 2015, 
EPA disapproved, for waters in Indian lands, Maine's mixing zone policy 
set forth in 38 M.R.S. 451. This provision allows the DEP to establish 
mixing zones that would allow the ``reasonable'' opportunity for 
dilution or mixture of pollutants before the receiving waters would be 
evaluated for WQS compliance.
    States are not required to adopt mixing zone policies into their 
WQS, but if they do, they are subject to EPA

[[Page 23257]]

review and approval. 40 CFR 131.13. A mixing zone is a limited area or 
volume of water where initial dilution of a discharge takes place, and 
where certain numeric criteria may be exceeded, but the designated uses 
of the waterbody as a whole must still be protected. EPA's guidance 
includes specific recommendations to ensure that mixing zones do not 
impair the designated uses of the waterbody as a whole. Among other 
things, a state mixing zone policy must ensure that pollutant 
concentrations in the mixing zone are not lethal to organisms passing 
through and do not cause significant human health risks; and that 
mixing zones do not endanger critical areas such as breeding or 
spawning grounds, drinking water intakes and sources, shellfish beds, 
or endangered or threatened species habitat. Maine's mixing zone law 
does not contain any of these or other protective safeguards to ensure 
the protection of designated uses. The only specific limitation on 
mixing zones in Maine's mixing zone statute is that they be 
``reasonable.'' There are also no state regulations that define the 
boundaries of a ``reasonable'' mixing zone. Therefore EPA disapproved 
Maine's law for waters in Indian lands as being inadequate to protect 
designated uses.
    b. What is EPA proposing? EPA proposes, for waters in Indian lands, 
a mixing zone policy that retains Maine's statutory mixing zone 
language and expands upon it by: 1. Including specific information that 
a request for a mixing zone must contain, and 2. including minimum 
requirements that any mixing zone must satisfy in order to qualify for 
approval by DEP.
    The proposed information requirements are intended to ensure that 
any discharger seeking DEP's approval of a mixing zone provides 
sufficient information for DEP to determine whether and to what extent 
a mixing zone may be authorized.
    The proposed mixing zone minimum requirements are intended to 
ensure that any mixing zone approved by DEP will not interfere with or 
impair the designated uses of the waterbody as a whole. They are 
consistent with recommendations in EPA's Water Quality Standards 
Handbook (2014).\58\ The proposed rule clarifies the extent to which 
water quality criteria may be exceeded in a mixing zone: chronic water 
quality criteria for those parameters approved by DEP may be exceeded 
within the mixing zone; acute water quality criteria may be exceeded 
for such parameters, but only within the zone of initial dilution 
inside the mixing zone, and the acute criteria must be met as close to 
the point of discharge as practicably attainable; and no water quality 
criteria may be exceeded outside of the boundary of a mixing zone as a 
result of the discharge for which the mixing zone was authorized. The 
proposed rule also specifies that a mixing zone must be as small as 
necessary, and that pollutant concentrations must be minimized and 
reflect the best practicable engineering design of the outfall to 
maximize initial mixing.The proposal includes a requirement that mixing 
zones be established consistent with the methodologies in Section 4.3 
and 4.4 of EPA's ``Technical Support Document for Water Quality-based 
Toxics Control'' EPA/505/2-90-001, dated March 1991. This requirement 
is consistent with EPA's recommendation that mixing zone policies 
describe the general procedures for defining and implementing mixing 
zones in terms of location, maximum size, shape, outfall design, and 
in-zone water quality, at a minimum.\59\ EPA also proposes a 
requirement that the mixing zone demonstration be based on the 
assumption that a pollutant does not degrade within the proposed mixing 
zone, unless a valid scientific study demonstrates otherwise. This 
assumption provides a conservative estimate of potential pollutant 
concentrations to be used when calculating allowable mixing zone 
discharges.
---------------------------------------------------------------------------

    \58\ USEPA. 2014. Water Quality Standards Handbook, Chapter 5. 
EPA-820-B-14-004.
    \59\ Id. at p. 4.
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    EPA proposes to prohibit the use of a mixing zone for 
bioaccumulative pollutants and for bacteria, consistent with EPA's 
guidance that recommends that mixing zone policies not allow mixing 
zones for discharges of these pollutants in order to protect the 
designated uses.\60\ EPA adopted this approach for bioaccumulative 
pollutants in 2000 when it amended its 1995 Final Water Quality 
Guidance for the Great Lakes System at 40 CFR part 132 to phase out 
mixing zones for existing discharges of bioaccumulative pollutants 
within the Great Lakes Basin and ban such mixing zones for new 
discharges within the Basin. Because fish tissue contamination tends to 
be a far-field problem affecting entire or downstream waterbodies 
rather than a near-field problem being confined to the area within a 
mixing zone, EPA has emphasized that it may be appropriate to restrict 
or eliminate mixing zones for bioaccumulative pollutants in certain 
situations such as where mixing zones may encroach on areas often used 
for fish harvesting, particularly for stationary species such as 
shellfish, and where there are uncertainties in the assimilative 
capacity of the waterbody.
---------------------------------------------------------------------------

    \60\ Id. at pp. 9-10.
---------------------------------------------------------------------------

    Similarly, because bacteria mixing zones may cause significant 
human health risks and endanger critical areas (e.g., recreational 
areas), EPA recommends that mixing zone policies not allow mixing zones 
for bacteria in waters designated for primary contact recreation. As 
explained in EPA's guidance, the presumption in waters designated for 
primary contact recreation is that primary contact recreation can 
safely occur throughout the waterbody and, therefore, that bacteria 
levels will not exceed criteria.\61\ People recreating in or through a 
bacteria mixing zone may be exposed to greater risk of illnesses than 
would otherwise be allowed by the criteria for protection of the 
recreation use. Primary contact recreation is a designated use for all 
waters in Maine, including in Indian lands. EPA is therefore proposing 
to prohibit mixing zones for bacteria for the waters in Indian lands 
because they could result in a significant human health risk.
---------------------------------------------------------------------------

    \61\ Id. at p. 10.
---------------------------------------------------------------------------

    EPA is not aware of instances where DEP has previously authorized 
mixing zones for bioaccumulative pollutants or bacteria, and therefore 
EPA does not expect that these prohibitions will pose hardship to 
existing dischargers.
    The proposed rule also establishes a number of restrictions to 
protect designated uses, such as requirements that the mixing zone be 
unlikely to jeopardize the continued existence of any endangered or 
threatened species listed under section 4 of the Endangered Species Act 
or result in the destruction or adverse modification of such species' 
critical habitat; not extend to drinking water intakes or sources; not 
cause significant human health risks; not endanger critical areas such 
as breeding and spawning grounds, habitat for state-listed threatened 
or endangered species, areas with sensitive biota, shellfish beds, 
fisheries, and recreational areas; not result in lethality to mobile, 
migrating, and drifting organisms passing through or within the mixing 
zone; not overlap with another mixing zone; not attract aquatic life; 
and not result in any objectionable color, odor, taste, or turbidity.

[[Page 23258]]

C. Proposed WQS for All Waters in Maine

1. Dissolved Oxygen Criteria for Class A Waters
    a. What Did EPA Disapprove? On June 5, 2015, EPA disapproved 
Maine's dissolved oxygen (DO) criteria for Class A fresh waters, set 
forth in 38 M.R.S. 465(2.B), for all waters in Maine, including waters 
in Indian lands. Maine's criteria state that ``The dissolved oxygen 
content of Class A waters shall be not less than 7 parts per million or 
75% of saturation, whichever is higher.'' Maine's DO criteria for Class 
A fresh waters are protective of all life stages of warmwater species 
and adult coldwater species, but are not high enough to protect the 
early life stages of coldwater species. Therefore, EPA disapproved the 
criteria because they do not protect early life stages of coldwater 
species and, therefore, do not protect the full aquatic life designated 
use.
    b. What Is EPA Proposing? EPA proposes year-round DO criteria for 
Class A waters that are identical to Maine's existing criteria (not 
less than 7 mg/L or 75% of saturation, whichever is higher).\62\
---------------------------------------------------------------------------

    \62\ Dissolved oxygen values expressed as mg/L are equivalent to 
the same values expressed as ppm.
---------------------------------------------------------------------------

    Maine's existing year-round criteria are higher, and more 
protective than, EPA's minimum DO recommendations for non-early life 
stages.\63\ EPA therefore proposes the same year-round criteria that 
Maine uses for these waters, in deference to Maine's determination of 
what is necessary to protect non-early life stages and to be consistent 
with Maine's criteria for Class B waters.
---------------------------------------------------------------------------

    \63\ EPA's recommended criteria for non-early life stages are 
expressed as 30 day mean (6.5 mg/L in cold water, 5.5 mg/L in warm 
water), 7 day mean minimum (5.0 mg/L in cold water, 4.0 mg/l in warm 
water), and 1 day minimum (4.0 mg/L in cold water, 3.0 mg/L in warm 
water). From USEPA. 1986. Quality Criteria for Water 1986, U.S. 
Environmental Protection Agency, Office of Water, Washington, DC. 
EPA 440/5-86-001. Dissolved Oxygen section.
---------------------------------------------------------------------------

    For fish spawning areas in Class A waters, for the period of 
October 1 through May 14, EPA proposes a 7-day mean DO concentration of 
>= 9.5 mg/L and a 1-day minimum of >= 8 mg/L. These proposed criteria 
to protect more sensitive early life stages of coldwater species are 
consistent with EPA's 304(a) criteria recommendations and will protect 
those stages against potentially damaging and lethal effects. EPA's 
proposed criteria for fish spawning areas for early life stages are 
also consistent with Maine's criteria for early life stages in Class B 
waters.
2. Waiver or Modification of WQS
    a. What Did EPA Disapprove? On June 5, 2015, for all waters in 
Maine, EPA disapproved 38 M.R.S. 363-D as it relates to WQS. Under this 
law, the DEP Commissioner (or designee) may waive or modify any 
provision of Maine's Title 38, Chapter 3 (related to the protection and 
improvement of waters), which includes WQS, to assist in any oil spill 
response activity conducted in accordance with the national or state 
contingency plans, or as otherwise directed by the federal on-scene 
coordinator or the Commissioner (or designee).
    EPA disapproved this statute as it relates to WQS, because it is 
not consistent with the minimum federal requirements that must be 
satisfied in order for a state to modify or waive a WQS. Specifically, 
waivers or modifications of WQS that would have the effect of removing 
a designated use or creating a subcategory of use, including waiving or 
modifying criteria necessary to support the use, may occur under the 
CWA only in accordance with 40 CFR 131.10(g) (which, among other 
things, requires a use attainability analysis). Before taking such 
action, states must provide public notice and a public hearing, and 
revised WQS are subject to EPA review and approval. Because 38 M.R.S. 
363-D does not contain any of these requirements, EPA disapproved it--
for WQS purposes only--as being inconsistent with federal law.
    b. What Is EPA Proposing? EPA proposes a regulation that states 
that 38 M.R.S. 363-D does not apply to state or federal WQS applicable 
to waters in Maine, including designated uses, criteria to protect 
designated uses, and antidegradation requirements. The proposed 
regulation would not interfere with the Commissioner's authority to 
modify applicable WQS through the removal of a use or establishment of 
a subcategory of a use if justified by a use attainability analysis, 
consistent with 40 CFR 131.10(g), or to grant a WQS variance, 
consistent with 40 CFR 131.14. Before taking such actions, the 
Commissioner must provide for public notice and a public hearing; and 
revised WQS, including WQS variances, are subject to EPA review and 
approval. Maine can still get short-term relief from compliance with 
WQS during oil spills through its permitting program. EPA's regulations 
at 40 CFR 122.3(d) provide a limited exception from the need to get an 
NPDES permit, and indirectly, to comply with WQS, for ``any discharge 
in compliance with the instructions of an On-Scene Coordinator pursuant 
to 40 CFR part 300 (The National Oil and Hazardous Substances Pollution 
Contingency Plan) or 33 CFR 153.10(e) (Pollution by Oil and Hazardous 
Substances).'' Maine has a similar permitting provision at 38 M.R.S. 
413(2-G.B) that it can rely on in such circumstances.

D. Proposed WQS for Waters in Maine Outside of Indian Lands

1. HHC for Phenol Consumption of Water Plus Organisms
    a. What Did EPA Disapprove? On March 16, 2015, EPA disapproved 
Maine's phenol criterion for the protection of human health consumption 
of water plus organisms, in DEP Rule Chapter 584, Appendix A, submitted 
to EPA on January 14, 2013, for waters throughout Maine. While DEP had 
based the criterion on EPA's then-current criterion recommendation, DEP 
made an inadvertent mathematical error that resulted in a less 
stringent criterion than EPA's recommendation (10,514 [micro]g/L rather 
than the correctly computed result of 10,267 [micro]g/L). In the 
absence of supporting scientific information to justify a finding that 
the less stringent criterion adequately protects the designated use, 
EPA disapproved the criterion for all waters in Maine as not being 
protective of the designated use and based on sound scientific 
rationale.
    b. What Is EPA Proposing? In June 2015, soon after EPA's March 2015 
disapproval, EPA updated its section 304(a) recommended criterion for 
phenol as part of a broader package of 304(a) criteria and identified a 
recommended criterion of 4000 [micro]g/L. When promulgating federal 
criteria, EPA bases the criteria on the most up-to-date scientific 
information. Consistent with the June 2015 recommendation, EPA 
accordingly proposes a phenol criterion for the protection of human 
health consumption of water plus organisms of 4000 [micro]g/L for 
waters in Maine outside of Indian lands. This proposed phenol criterion 
is based on EPA's default inputs for relative source contribution, body 
weight, drinking water intake, and pollutant-specific reference doses 
and cancer slope factors, discussed in more detail in section IV.A.1.a. 
Since this criterion will apply in state waters outside of Indian 
lands, EPA used Maine's default fish consumption rate of 32.4 g/day, as 
well as a cancer risk level of 10-6 consistent with DEP Rule Chapter 
584. The FCR reflects local survey data, and the CRL is consistent with 
EPA's recommendation. Therefore, the proposed criterion is protective 
of human health in waters in Maine

[[Page 23259]]

outside of Indian lands, for the reasons discussed in EPA's 2015 
criteria update.

V. Economic Analysis

    These WQS may serve as a basis for development of NPDES permit 
limits. Maine has NPDES permitting authority, through which it ensures 
that discharges to waters of the state do not cause or contribute to an 
exceedance of WQS. EPA evaluated the potential costs to NPDES 
dischargers associated with state implementation of EPA's proposed WQS. 
This analysis is documented in the ``Economic Analysis for Proposal of 
Certain Federal Water Quality Standards Applicable to Maine,'' which 
can be found in the record for this rulemaking.
    Any NPDES-permitted facility that discharges pollutants for which 
the proposed WQS are more stringent than the WQS on which permit limits 
are currently based could potentially incur compliance costs. The types 
of affected facilities could include industrial facilities and POTWs 
discharging wastewater to surface waters (i.e., point sources). EPA 
attributed to the proposed rule only those incremental costs that are 
above the costs associated with compliance with water quality based 
effluent limits (WQBELs) in current permits. Proposed criteria for pH, 
temperature, ammonia, and all but one HHC (for waters in Indian lands), 
proposed criteria for phenol (for state waters outside Indian lands), 
and proposed criteria for dissolved oxygen (for all state waters) are 
not expected to result in incremental costs to permitted dischargers. 
The cost analysis identifies potential costs of compliance with one HHC 
(bis(2-ethylhexyl)phthalate), bacteria, and the proposed mixing zone 
policy for waters in Indian lands.
    EPA did not fully evaluate the potential for costs to nonpoint 
sources for this preliminary analysis. Very little data were available 
to assess the potential for the rule to result in WQS exceedances 
attributable to nonpoint sources. It is difficult to model and evaluate 
the potential cost impacts of this proposed rule to nonpoint sources 
because they are intermittent, variable, and occur under hydrologic or 
climatic conditions associated with precipitation events. Finally, 
legacy contamination (e.g., in sediment) may be a source of ongoing 
loading. Atmospheric deposition may also contribute loadings of the 
pollutants of concern (e.g., mercury). EPA did not estimate sediment 
remediation costs, or air pollution controls costs, for this 
preliminary analysis.

A. Identifying Affected Entities

    EPA identified 33 dischargers to waters in Indian lands and their 
tributaries, two facilities that discharge phenol to other state 
waters, and 26 facilities that discharge to Class A waters throughout 
the state. EPA identified 16 point source facilities that could incur 
additional costs as a result of this proposed rule. Of these 
potentially affected facilities, eight are major dischargers and eight 
are minor dischargers. Two are industrial dischargers and the remaining 
14 are publicly owned treatment works (POTWs). EPA did not include 
general permit facilities in its analysis because data for such 
facilities are limited. EPA evaluated all of the potentially affected 
facilities.

B. Method for Estimating Costs

    For the 16 facilities that may incur costs, EPA evaluated existing 
baseline permit conditions and potential to exceed new effluent limits 
based on the proposed rule. In instances of exceedances of projected 
effluent limitations under the proposed criteria, EPA determined the 
likely compliance scenarios and costs. Only compliance actions and 
costs that would be needed above the baseline level of controls are 
attributable to the proposed rule.
    EPA assumed that dischargers will pursue the least cost means of 
compliance with WQBELs. Incremental compliance actions attributable to 
the proposed rule may include pollution prevention, end-of-pipe 
treatment, and alternative compliance mechanisms (e.g., variances). EPA 
annualized capital costs, including study (e.g., variance) and program 
(e.g., pollution prevention) costs, over 20 years using a 3% discount 
rate to obtain total annual costs per facility.

C. Results

    Based on the results for the 16 facilities, EPA estimated a total 
annual cost of approximately $213,000 to $1.0 million. The low end of 
the range reflects $28,000 in annual pollution prevention costs for one 
facility and $185,300 in incremental annual operating costs for all 
POTWs to disinfect year-round and for some POTWs to dechlorinate year 
round. The high end of the cost range reflects incremental annual 
operating costs of $705,200 for all POTWs to both disinfect and 
dechlorinate year-round; the maximum estimated annual cost of $273,000 
to comply with the updated mixing zone policy; and $43,096 in estimated 
annual costs for one facility to provide end-of-pipe treatment for 
bis(2-ethylhexyl)phthalate.
    If the proposed criteria result in an incremental increase in 
impaired waters, resulting in the need for TMDL development, there 
could also be some costs to nonpoint sources of pollution. EPA had very 
limited information with which to assess potential impacts of the 
proposed revisions on ambient water quality. Given the scope of the 
proposed rule on certain waters and pollutants (notably toxic 
pollutants) and existing controls on wide-ranging nonpoint source 
pollution sources including in statewide TMDLs, EPA determined that any 
incremental costs on nonpoint sources are unlikely to be significant.

VI. Statutory and Executive Order Reviews

A. Executive Order 12866 (Regulatory Planning and Review) and Executive 
Order 13563 (Improving Regulation and Regulatory Review)

    This action is not a significant regulatory action and was, 
therefore, not submitted to the Office of Management and Budget (OMB) 
for review. The proposed rule does not establish any requirements 
directly applicable to regulated entities or other sources of 
pollutants. However, these WQS may serve as a basis for development of 
NPDES permit limits. Maine has NPDES permitting authority, through 
which it ensures that discharges to waters of the state do not cause or 
contribute to an exceedance of WQS. In the spirit of Executive Order 
12866, EPA evaluated the potential costs to NPDES dischargers 
associated with state implementation of EPA's proposed criteria. This 
analysis, Economic Analysis for Proposal of Certain Federal Water 
Quality Standards Applicable to Maine, is summarized in section V of 
the preamble and is available in the docket.

B. Paperwork Reduction Act

    This action does not impose any direct new information collection 
burden under the provisions of the Paperwork Reduction Act, 44 U.S.C. 
3501 et seq. Actions to implement these WQS could entail additional 
paperwork burden. Burden is defined at 5 CFR 1320.3(b). This action 
does not include any information collection, reporting, or record-
keeping requirements.

C. Regulatory Flexibility Act

    I certify that this action will not have a significant economic 
impact on a substantial number of small entities under the RFA. This 
action will not impose any requirements on small entities. Small 
entities, such as small

[[Page 23260]]

businesses or small governmental jurisdictions, are not directly 
regulated by this rule. This proposed rule will thus not impose any 
requirements on small entities. We continue to be interested, however, 
in the potential impacts of the proposed rule on small entities and 
welcome comments on issues related to such impacts.

D. Unfunded Mandates Reform Act

    This action contains no federal mandates under the provisions of 
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), 2 U.S.C. 
1531-1538 for state, local, or tribal governments or the private 
sector. As these water quality criteria are not self-implementing, 
EPA's action imposes no enforceable duty on any state, local or tribal 
governments or the private sector. Therefore, this action is not 
subject to the requirements of sections 202 or 205 of the UMRA. This 
action is also not subject to the requirements of section 203 of UMRA 
because it contains no regulatory requirements that could significantly 
or uniquely affect small governments.

E. Executive Order 13132

    This action does not have federalism implications. It will not have 
substantial direct effects on the states, on the relationship between 
the national government and the states, or on the distribution of power 
and responsibilities among the various levels of government.

F. Executive Order 13175 (Consultation and Coordination With Indian 
Tribal Governments)

    This action has tribal implications. However, it would neither 
impose substantial direct compliance costs on federally recognized 
tribal governments, nor preempt tribal law. In the state of Maine, 
there are four federally recognized Indian tribes represented by five 
tribal governments. As a result of the unique jurisdictional provisions 
of the Maine Indian Claims Settlement Act, as described above, the 
state has jurisdiction for setting water quality standards for all 
waters in Indian lands in Maine. This rule would affect federally 
recognized Indian tribes in Maine because the water quality standards 
being proposed would apply to all waters in Indian lands and some will 
also apply to waters outside of Indian lands where the sustenance 
fishing designated use established by 30 M.R.S. 6207(4) and (9) 
applies, and because many of the proposed criteria for such waters are 
protective of the sustenance fishing designated use, which is based in 
the Indian claims settlement acts in Maine.
    The EPA consulted with tribal officials under the EPA Policy on 
Consultation and Coordination with Indian Tribes early in the process 
of developing this proposed rule to permit them to have meaningful and 
timely input into its development. A summary of that consultation is 
provided in ``Summary of Tribal Consultations Regarding Water Quality 
Standards Applicable to Waters in Indian Lands within the State of 
Maine,'' which is available in the docket for this rulemaking.

G. Executive Order 13045 (Protection of Children From Environmental 
Health and Safety Risks)

    The EPA interprets Executive Order 13045 as applying only to those 
regulatory actions that concern environmental health or safety risks 
that the EPA has reason to believe may disproportionately affect 
children, per the definition of ``covered regulatory action'' in 
section 2-202 of the Executive Order. This action is not subject to 
Executive Order 13045 because it does not concern an environmental 
health risk or safety risk that may disproportionately affect children.
    The public is invited to submit comments or identify peer-reviewed 
studies and data that assess effects of early life exposure.

H. Executive Order 13211 (Actions That Significantly Affect Energy 
Supply, Distribution, or Use)

    This action is not subject to Executive Order 13211, because it is 
not a significant regulatory action under Executive Order 12866.

I. National Technology Transfer and Advancement Act of 1995

    This action does not involve technical standards.

J. Executive Order 12898 (Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations)

    The EPA believes the human health or environmental risk addressed 
by this action will not have potential disproportionately high and 
adverse human health or environmental effects on minority, low-income 
or indigenous populations.
    Conversely, this action would increase protection for indigenous 
populations in Maine from disproportionately high and adverse human 
health effects. EPA developed the criteria included in this proposed 
rule specifically to protect Maine's designated uses, using the most 
current science, including local and regional information on fish 
consumption. Applying these criteria to waters in the state of Maine 
will afford a greater level of protection to both human health and the 
environment.

List of Subjects in 40 CFR Part 131

    Environmental protection, Indians--lands, Intergovernmental 
relations, Reporting and recordkeeping requirements, Water pollution 
control.

    Dated: April 11, 2016.
Gina McCarthy,
Administrator.
    For the reasons set forth in the preamble, EPA proposes to amend 40 
CFR part 131 as follows:

PART 131--WATER QUALITY STANDARDS

0
1. The authority citation for part 131 continues to read as follows:

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

Subpart D--Federally Promulgated Water Quality Standards

0
2. Add Sec.  131.43 to read as follows:

Sec.  131.43  Maine.

    (a) Human health criteria for toxics for waters in Indian lands and 
for waters outside of Indian lands where the sustenance fishing 
designated use established by 30 m.r.s. 6207(4) and (9) applies. The 
criteria for toxic pollutants for the protection of human health are 
set forth in the following table 1:

                                     Table 1--Proposed Human Health Criteria
----------------------------------------------------------------------------------------------------------------
                                                                                      Water &
                          Chemical name                               CAS No.        organisms    Organisms only
                                                                                   ([micro]g/L)    ([micro]g/L)
----------------------------------------------------------------------------------------------------------------
1. 1,1,2,2-Tetrachloroethane....................................         79-34-5            0.09             0.2
2. 2-Trichloroethane............................................         79-00-5            0.31            0.66
3. 1,1-Dichloroethylene.........................................         75-35-4             300            1000

[[Page 23261]]

 
4. 1,2,4,5-Tetrachlorobenzene...................................         95-94-3           0.002           0.002
5. 1,2,4-Trichlorobenzene.......................................        120-82-1          0.0056          0.0056
6. 1,2-Dichlorobenzene..........................................         95-50-1             200             300
7. 1,2-Dichloropropane..........................................         78-87-5  ..............             2.3
8. 1,2-Diphenylhydrazine........................................        122-66-7            0.01            0.02
9. 1,2-Trans-Dichloroethylene...................................        156-60-5              90             300
10. 1,3-Dichlorobenzene.........................................        541-73-1               1               1
11. 1,3-Dichloropropene.........................................        542-75-6            0.21            0.87
12. 1,4-Dichlorobenzene.........................................        106-46-7  ..............              70
13. 2,4,5-Trichlorophenol.......................................         95-95-4              40              40
14. 2,4,6-Trichlorophenol.......................................         88-06-2            0.20            0.21
15. 2,4-Dichlorophenol..........................................        120-83-2               4               4
16. 2,4-Dimethylphenol..........................................        105-67-9              80             200
17. 2,4-Dinitrophenol...........................................         51-28-5               9              30
18. 2,4-Dinitrotoluene..........................................        121-14-2           0.036            0.13
19. 2-Chloronaphthalene.........................................         91-58-7              90              90
20. 2-Chlorophenol..............................................         95-57-8              20              60
21. 2-Methyl-4,6-Dinitrophenol..................................        534-52-1               1               2
22. 3,3'-Dichlorobenzidine......................................         91-94-1          0.0096           0.011
23. 4,4'-DDD....................................................         72-54-8         9.3E-06         9.3E-06
24. 4,4'-DDE....................................................         72-55-9         1.3E-06         1.3E-06
25. 4,4'-DDT....................................................         50-29-3         2.2E-06         2.2E-06
26. Acenaphthene................................................         83-32-9               6               7
27. Acrolein....................................................        107-02-8               3  ..............
28. Aldrin......................................................        309-00-2         5.8E-08         5.8E-08
29. alpha-BHC...................................................        319-84-6         2.9E-05         2.9E-05
30. alpha-Endosulfan............................................        959-98-8               2               2
31. Anthracene..................................................        120-12-7              30              30
32. Antimony....................................................       7440-36-0             4.8              45
33. Benzene.....................................................         71-43-2            0.40             1.2
34. Benzo (a) Anthracene........................................         56-55-3         9.8E-05         9.8E-05
35. Benzo (a) Pyrene............................................         50-32-8         9.8E-06         9.8E-06
36. Benzo (b) Fluoranthene......................................        205-99-2         9.8E-05         9.8E-05
37. Benzo (k) Fluoranthene......................................        207-08-9         0.00098         0.00098
38. beta-BHC....................................................        319-85-7          0.0010          0.0011
39. beta-Endosulfan.............................................      33213-65-9               3               3
40. Bis(2-Chloro-1-Methylethyl) Ether...........................        108-60-1             100             300
41. Bis(2-Chloroethyl) Ether....................................        111-44-4           0.026            0.16
42. Bis(2-Ethylhexyl) Phthalate.................................        117-81-7           0.028           0.028
43. Bromoform...................................................         75-25-2             4.0             8.7
44. Butylbenzyl Phthalate.......................................         85-68-7          0.0077          0.0077
45. Carbon Tetrachloride........................................         56-23-5             0.2             0.3
46. Chlordane...................................................         57-74-9         2.4E-05         2.4E-05
47. Chlorobenzene...............................................        108-90-7              40              60
48. Chlorodibromomethane........................................        124-48-1  ..............             1.5
49. Chrysene....................................................        218-01-9  ..............          0.0098
50. Cyanide.....................................................         57-12-5               4              30
51. Dibenzo (a,h) Anthracene....................................         53-70-3         9.8E-06         9.8E-06
52. Dichlorobromomethane........................................         75-27-4  ..............               2
53. Dieldrin....................................................         60-57-1         9.3E-08         9.3E-08
54. Diethyl Phthalate...........................................         84-66-2              50              50
55. Dimethyl Phthalate..........................................        131-11-3             100             100
56. Di-n-Butyl Phthalate........................................         84-74-2               2               2
57. Dinitrophenols..............................................      25550-58-7              10              70
58. Endosulfan Sulfate..........................................       1031-07-8               3               3
59. Endrin......................................................         72-20-8           0.002           0.002
60. Endrin Aldehyde.............................................       7421-93-4            0.09            0.09
61. Ethylbenzene................................................        100-41-4             8.9             9.5
62. Fluoranthene................................................        206-44-0               1               1
63. Fluorene....................................................         86-73-7               5               5
64. gamma-BHC (Lindane).........................................         58-89-9            0.33  ..............
65. Heptachlor..................................................         76-44-8         4.4E-07         4.4E-07
66. Heptachlor Epoxide..........................................       1024-57-3         2.4E-06         2.4E-06
67. Hexachlorobenzene...........................................        118-74-1         5.9E-06         5.9E-06
68. Hexachlorobutadiene.........................................         87-68-3          0.0007          0.0007
69. Hexachlorocyclohexane-Technical.............................        608-73-1         0.00073         0.00076
70. Hexachlorocyclopentadiene...................................         77-47-4             0.3             0.3
71. Hexachloroethane............................................         67-72-1            0.01            0.01
72. Indeno (1,2,3-cd) Pyrene....................................        193-39-5         9.8E-05         9.8E-05
73. Isophorone..................................................         78-59-1              28             140

[[Page 23262]]

 
74. Methoxychlor................................................         72-43-5           0.001  ..............
75. Methylene Chloride..........................................         75-09-2  ..............              90
76. Methylmercury...............................................      22967-92-6  ..............   \a\ 0.02 (mg/
                                                                                                             kg)
77. Nickel......................................................       7440-02-0              20              24
78. Nitrobenzene................................................         98-95-3              10              40
79. Nitrosamines................................................  ..............          0.0007          0.0322
80. N-Nitrosodibutylamine.......................................        924-16-3          0.0044           0.015
81. N-Nitrosodiethylamine.......................................         55-18-5          0.0007          0.0322
82. N-Nitrosodimethylamine......................................         62-75-9         0.00065            0.21
83. N-Nitrosodi-n-propylamine...................................        621-64-7          0.0042           0.035
84. N-Nitrosodiphenylamine......................................         86-30-6            0.40            0.42
85. N-Nitrosopyrrolidine........................................        930-55-2  ..............             2.4
86. Pentachlorobenzene..........................................        608-93-5           0.008           0.008
87. Pentachlorophenol...........................................         87-86-5           0.003           0.003
88. Phenol......................................................        108-95-2           3,000          20,000
89. Polychlorinated Biphenyls (PCBs)............................       1336-36-3     \b\ 4.5E-06     \b\ 4.5E-06
90. Pyrene......................................................        129-00-0               2               2
91. Selenium....................................................       7782-49-2              21              58
92. Toluene.....................................................        108-88-3              24              39
93. Toxaphene...................................................       8001-35-2         5.3E-05         5.3E-05
94. Trichloroethylene...........................................         79-01-6             0.3             0.5
95. Vinyl Chloride..............................................         75-01-4           0.019            0.12
96. Zinc........................................................       7440-66-6             300             360
----------------------------------------------------------------------------------------------------------------
\a\ This criterion is expressed as the fish tissue concentration of methylmercury (mg methylmercury/kg fish) and
  applies equally to fresh and marine waters.
\b\ This criterion applies to total PCBs (e.g., the sum of all congener or isomer or homolog or Aroclor
  analyses).

    (b) Bacteria criteria for waters in Indian lands. (1) The bacteria 
content of Class AA and Class A waters shall be as naturally occurs, 
and the minimum number of Escherichia coli bacteria shall not exceed a 
geometric mean of 100 colony-forming units per 100 milliliters (cfu/100 
ml) in any 30-day interval; nor shall 320 cfu/100 ml be exceeded more 
than 10% of the time in any 30-day interval.
    (2) In Class B, Class C, and Class GPA waters, the number of 
Escherichia coli bacteria shall not exceed a geometric mean of 100 
colony forming units per 100 milliliters (cfu/100 ml) in any 30- day 
interval; nor shall 320 cfu/100 ml be exceeded more than 10% of the 
time in any 30-day interval.
    (3) The bacteria content of Class SA waters shall be as naturally 
occurs, and the number of Enterococcus bacteria shall not exceed a 
geometric mean of 30 cfu/100 ml in any 30-day interval, nor shall 110 
cfu/100 ml be exceeded more than 10% of the time in any 30-day 
interval.
    (4) In Class SA shellfish harvesting areas, the number of total 
coliform bacteria in samples representative of the waters in shellfish 
harvesting areas shall not exceed a geometric mean for each sampling 
station of 70 MPN (most probable number) per 100 ml, with not more than 
10% of samples exceeding 230 MPN per 100 ml for the taking of 
shellfish.
    (5) In Class SB and SC waters, the number of Enterococcus bacteria 
shall not exceed a geometric mean of 30 cfu/100 ml in any 30-day 
interval, nor shall 110 cfu/100 ml be exceeded more than 10% of the 
time in any 30-day interval.
    (c) Ammonia criteria for fresh waters in Indian lands. (1) The one-
hour average concentration of total ammonia nitrogen (in mg TAN/L) 
shall not exceed, more than once every three years, the criterion 
maximum concentration (i.e., the ``CMC,'' or ``acute criterion'') set 
forth in Tables 2 and 3 of this section.
    (2) The thirty-day average concentration of total ammonia nitrogen 
(in mg TAN/L) shall not exceed, more than once every three years, the 
criterion continuous concentration (i.e., the ``CCC,'' or ``chronic 
criterion'') set forth in Table 4.
    (3) In addition, the highest four-day average within the same 30-
day period as in 2 shall not exceed 2.5 times the CCC, more than once 
every three years.
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    (d) pH criteria for fresh waters in Indian lands. The pH of fresh 
waters shall fall within the range of 6.5 to 8.5.
    (e) Temperature criteria for tidal waters in Indian lands. (1) The 
maximum acceptable cumulative increase in the weekly average 
temperature resulting from all artificial sources is 1 [deg]C (1.8 
[deg]F) during all seasons of the year, provided that the summer 
maximum is not exceeded.
    (i) Weekly average temperature increase shall be compared to 
baseline thermal conditions and shall be calculated using the daily 
maxima averaged over a 7-day period.
    (ii) Baseline thermal conditions shall be measured at or modeled 
from a site where there is no artificial thermal addition from any 
source, and which is in reasonable proximity to the thermal discharge 
(within 5 miles), and which has similar hydrography to that of the 
receiving waters at the discharge.
    (2) Natural temperature cycles characteristic of the water body 
segment shall not be altered in amplitude or frequency.
    (3) During the summer months (for the period from May 15 through 
September 30), water temperatures shall not exceed a weekly average 
summer maximum threshold of 18 [deg]C (64.4[emsp14][deg]F) (calculated 
using the daily maxima averaged over a 7-day period).
    (f) Natural conditions provisions for waters in Indian lands. (1) 
The provision in Title 38 of Maine Revised Statutes 464(4.C) which 
reads: ``Where natural conditions, including, but not limited to, 
marshes, bogs and abnormal concentrations of wildlife cause the 
dissolved oxygen or other water quality criteria to fall below the 
minimum standards specified in section 465, 465-A and 465-B, those 
waters shall not be considered to be failing to attain their 
classification because of those natural conditions,'' does not apply to 
water quality criteria intended to protect human health.
    (2) The provision in Title 38 of Maine Revised Statutes 420(2.A) 
which reads ``Except as naturally occurs or as provided in paragraphs B 
and C, the board shall regulate toxic substances in the surface waters 
of the State at the levels set forth in federal water quality criteria 
as established by the United States Environmental Protection Agency 
pursuant to the Federal Water Pollution Control Act, Public Law 92-500, 
Section 304(a), as amended,'' does not apply to water quality criteria 
intended to protect human health.
    (g) Mixing zone policy for waters in Indian lands--(1) Establishing 
a mixing zone. (i) The Department of Environmental Protection 
(``department'') may establish a mixing zone for any discharge at the 
time of application for a waste discharge license if all of the 
requirements set forth in paragraphs (g)(2) and (3) of this section are 
satisfied. The department shall attach a description of the mixing zone 
as a condition of a license issued for that discharge. After 
opportunity for a hearing in accordance with 38 MRS section 345-A, the 
department may establish by order a mixing zone with respect to any 
discharge for which a license has been issued pursuant to section 414 
or for which an exemption has been granted by virtue of 38 MRS section 
413, subsection 2.
    (ii) The purpose of a mixing zone is to allow a reasonable 
opportunity for dilution, diffusion or mixture of pollutants with the 
receiving waters such that an applicable criterion may be exceeded 
within a defined area of the waterbody while still protecting the 
designated use of the waterbody as a whole. In determining the extent 
of any mixing zone to be established under this section, the department 
will require from the applicant information concerning the nature and 
rate of the discharge; the nature and rate of existing discharges to 
the waterway; the size of the waterway and the rate of flow therein; 
any relevant seasonal, climatic, tidal and natural variations in such 
size, flow, nature and rate; the uses of the waterways that could be 
affected by the discharge, and such other and further evidence as in 
the department's judgment will enable it to establish a reasonable 
mixing zone for such discharge. An order establishing a mixing zone may 
provide that the extent thereof varies in order to take into account 
seasonal, climatic, tidal, and natural variations in the size and flow 
of, and the nature and rate of, discharges to the waterway.
    (2) Mixing zone information requirements. At a minimum, any request 
for a mixing zone must:
    (i) Describe the amount of dilution occurring at the boundaries of 
the proposed mixing zone and the size, shape, and location of the area 
of mixing, including the manner in which diffusion and dispersion 
occur;
    (ii) Define the location at which discharge-induced mixing ceases;
    (iii) Document the substrate character and geomorphology within the 
mixing zone;
    (iv) Document background water quality concentrations;
    (v) Address the following factors:
    (A) Whether adjacent mixing zones overlap;
    (B) Whether organisms would be attracted to the area of mixing as a 
result of the effluent character; and
    (C) Whether the habitat supports endemic or naturally occurring 
species.
    (vi) Provide all information necessary to demonstrate whether the 
requirements in paragraph (g)(3) of this section are satisfied.
    (3) Mixing zone requirements. (i) Mixing zones shall be established 
consistent with the methodologies in Sections 4.3 and 4.4 of the 
``Technical Support Document for Water Quality-based Toxics Control'' 
EPA/505/2-90-001, dated March 1991.
    (ii) The mixing zone demonstration shall be based on the assumption 
that a pollutant does not degrade within the proposed mixing zone, 
unless:
    (A) Scientifically valid field studies or other relevant 
information demonstrate that degradation of the pollutant is expected 
to occur under the full range of environmental conditions expected to 
be encountered; and
    (B) Scientifically valid field studies or other relevant 
information address other factors that affect the level of pollutants 
in the water column including, but not limited to, resuspension of 
sediments, chemical speciation, and biological and chemical 
transformation.
    (iii) Water quality within an authorized mixing zone is allowed to 
exceed chronic water quality criteria for those parameters approved by 
the department. Acute water quality criteria may be exceeded for such 
parameters within the zone of initial dilution inside the mixing zone. 
Acute criteria shall be met as close to the point of discharge as 
practicably attainable. Water quality criteria shall not be violated 
outside of the boundary of a mixing zone as a result of the discharge 
for which the mixing zone was authorized.
    (iv) Mixing zones shall be as small as practicable. The 
concentrations of pollutants present shall be minimized and shall 
reflect the best practicable engineering design of the outfall to 
maximize initial mixing. Mixing zones shall not be authorized for 
bioaccumulative pollutants or bacteria.
    (v) In addition to the requirements above, the department may 
approve a mixing zone only if the mixing zone:
    (A) Is sized and located to ensure that there will be a continuous 
zone of passage that protects migrating, free-swimming, and drifting 
organisms;
    (B) Will not result in thermal shock or loss of cold water habitat 
or otherwise interfere with biological communities or populations of 
indigenous species;
    (C) Is not likely to jeopardize the continued existence of any 
endangered or threatened species listed under

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section 4 of the ESA or result in the destruction or adverse 
modification of such species' critical habitat;
    (D) Will not extend to drinking water intakes and sources;
    (E) Will not otherwise interfere with the designated or existing 
uses of the receiving water or downstream waters;
    (F) Will not promote undesirable aquatic life or result in a 
dominance of nuisance species;
    (G) Will not endanger critical areas such as breeding and spawning 
grounds, habitat for state-listed threatened or endangered species, 
areas with sensitive biota, shellfish beds, fisheries, and recreational 
areas;
    (H) Will not contain pollutant concentrations that are lethal to 
mobile, migrating, and drifting organisms passing through the mixing 
zone;
    (I) Will not contain pollutant concentrations that may cause 
significant human health risks considering likely pathways of exposure;
    (J) Will not result in an overlap with another mixing zone;
    (K) Will not attract aquatic life;
    (L) Will not result in a shore-hugging plume; and
    (M) Is free from:
    (1) Substances that settle to form objectionable deposits;
    (2) Floating debris, oil, scum, and other matter in concentrations 
that form nuisances; and
    (3) Objectionable color, odor, taste, or turbidity.
    (h) Dissolved oxygen criteria for class A waters throughout the 
State of Maine, including in Indian lands. The dissolved oxygen content 
of Class A waters shall not be less than 7 ppm (7 mg/L) or 75% of 
saturation, whichever is higher, year-round. For the period from 
October 1 through May 14, in fish spawning areas, the 7-day mean 
dissolved oxygen concentration shall not be less than 9.5 ppm (9.5 mg/
L), and the 1-day minimum dissolved oxygen concentration shall not be 
less than 8 ppm (8.0 mg/L).
    (i) Waiver or modification of protection and improvement laws for 
waters throughout the State of Maine, including in Indian lands. For 
all waters in Maine, the provisions in Title 38 of Maine Revised 
Statutes 363-D do not apply to state or federal water quality standards 
applicable to waters in Maine, including designated uses, criteria to 
protect existing and designated uses, and antidegradation policies.
    (j) Phenol criterion for the protection of human health for Maine 
Waters outside of Indian lands. The phenol criterion to protect human 
health for the consumption of water and organisms is 4000 micrograms 
per liter.

[FR Doc. 2016-09025 Filed 4-19-16; 8:45 am]
 BILLING CODE 6560-50-C