Document ID: EPA-HQ-OW-2019-0675-0001
Agency: epa
Document Type: Notice
Title: Draft Ambient Water Quality Criteria Recommendations for Lakes and Reservoirs of the Conterminous United States: Information Supporting the Development of Numeric Nutrient Criteria
Posted Date: 2020-05-22T04:00Z

[Federal Register Volume 85, Number 100 (Friday, May 22, 2020)]
[Notices]
[Pages 31184-31185]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-11126]

[[Page 31184]]

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ENVIRONMENTAL PROTECTION AGENCY

[EPA-HQ-OW-2019-0675; FRL 10008-88-OW]

Draft Ambient Water Quality Criteria Recommendations for Lakes 
and Reservoirs of the Conterminous United States: Information 
Supporting the Development of Numeric Nutrient Criteria

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of availability; request for comments.

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SUMMARY: The United States Environmental Protection Agency (EPA) 
announces the release of the Draft Ambient Water Quality Criteria 
Recommendations for Lakes and Reservoirs of the Conterminous United 
States: Information Supporting the Development of Numeric Nutrient 
Criteria for a 60-day comment period for scientific input. These draft 
national criteria recommendations are models for total nitrogen and 
total phosphorus concentrations in lakes and reservoirs to protect 
three different designated uses--aquatic life, recreation, and drinking 
water source protection--from the adverse effects of nutrient 
pollution. Nutrient pollution can degrade the conditions of water 
bodies worldwide, and in lakes and reservoirs the effects of excess 
nitrogen and phosphorus may be particularly evident. These draft 
criteria recommendations are based on stressor-response models, which 
link nutrient pollution stressors (nitrogen, phosphorus) to responses 
associated with protection of designated uses. These draft criteria 
recommendations, when finalized, will replace the EPA's previously 
recommended ambient nutrient criteria for lakes and reservoirs. Models 
and associated criteria provided in this document are based on national 
data. States and authorized tribes can also incorporate local data, 
when available, into the national models, helping states and authorized 
tribes to develop numeric nutrient criteria that apply relationships 
estimated from national data while accounting for unique local 
conditions.
    Following closure of this 60-day public comment period, the EPA 
will consider the comments, revise the draft document, as appropriate, 
and then publish a final document that will provide recommendations for 
states and authorized tribes to establish water quality standards under 
the Clean Water Act (CWA).

DATES: Comments must be received on or before July 21, 2020.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-OW-
2019-0675, to the Federal eRulemaking Portal: https://www.regulations.gov (preferred method). Follow the online instructions 
for submitting comments. Once submitted, comments cannot be edited or 
withdrawn. The 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. The 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 https://www2.epa.gov/dockets/commenting-epa-dockets.
    Out of an abundance of caution for members of the public and our 
staff, the EPA Docket Center and Reading Room was closed to public 
visitors on March 31, 2020, to reduce the risk of transmitting COVID-
19. Our Docket Center staff will continue to provide remote customer 
service via email, phone, and webform. We encourage the public to 
submit comments via https://regulations.gov, as there is a temporary 
suspension of mail delivery to the EPA, and no hand deliveries are 
currently accepted. For further information on the EPA Docket Center 
services and the current status, please visit us online at https://www.epa.gov/dockets.

FOR FURTHER INFORMATION CONTACT: Lester Yuan, Health and Ecological 
Criteria Division, Office of Water (Mail Code 4304T), Environmental 
Protection Agency, 1200 Pennsylvania Avenue NW, Washington, DC 20460; 
telephone number: (202) 566-0908; email address: yuan.lester@epa.gov.

SUPPLEMENTARY INFORMATION: 

I. General Information

A. How can I get copies of this document and other related information?

    You may access this Federal Register document electronically from 
the Government Printing Office under the ``Federal Register'' listings 
in govinfo (https://www.govinfo.gov/app/collection/FR/).

II. What is nutrient pollution and why is the EPA concerned about it?

    While certain levels of nutrients are essential for healthy aquatic 
ecosystems, nutrient pollution, or the excess loading of nitrogen and 
phosphorus, can degrade the conditions of water bodies and potentially 
make them unsafe for aquatic life, recreation, or to use as drinking 
water sources. Nutrient pollution stimulates excess growth of algae, 
which can limit the recreational use of lakes and reservoirs. 
Overabundant algae also increase the amount of organic matter in a lake 
or reservoir, which, when decomposed, can depress dissolved oxygen 
concentrations below levels needed to sustain aquatic life. In extreme 
cases, the depletion of dissolved oxygen causes fish kills. Nutrient 
pollution can stimulate the excess growth of nuisance algae, such as 
cyanobacteria, which can produce cyanotoxins that are toxic to animals 
and humans. Elevated concentrations of these cyanotoxins can reduce the 
suitability of a lake or reservoir for recreation and as a source of 
drinking water.

III. Information on the Draft Ambient Water Quality Criteria 
Recommendations for Lakes and Reservoirs

    These draft ambient water quality criteria recommendations for 
lakes and reservoirs are part of the EPA's ongoing efforts to support 
states and authorized tribes in developing and adopting numeric 
nutrient criteria. Numeric nutrient criteria provide an important tool 
for managing the effects of nutrient pollution by providing nutrient 
goals that support the protection and maintenance of the designated 
uses of the waters of the United States. Recognizing the utility of 
such criteria, the EPA published recommended numeric nutrient criteria 
for lakes and reservoirs for twelve out of fourteen ecoregions of the 
conterminous United States from 2000 to 2001. These criteria were 
derived by analyzing available data on the concentrations of total 
nitrogen, total phosphorus, chlorophyll a, and Secchi depth. Scientific 
understanding of the relationships between nutrient concentrations and 
deleterious effects in lakes has increased since 2001, and 
standardized, high-quality data collected from lakes across the United 
States have become available. In this document, the EPA describes 
analyses of these new data and provides models to derive draft numeric 
nutrient criteria for lakes that

[[Page 31185]]

replace the recommended numeric nutrient criteria of 2000 and 2001. 
These draft models and associated recommended criteria are provided in 
accordance with the provisions of Section 304(a) of the CWA for the EPA 
to revise ambient water quality criteria from time to time to reflect 
the latest scientific knowledge. CWA Section 304(a) national water 
quality criteria serve only as non-binding recommendations to states 
and authorized tribes in defining ambient water concentrations that 
will protect against adverse effects to aquatic life and human health. 
The ecological responses on which these draft models and criteria are 
based were selected by applying a risk assessment approach to 
explicitly link nutrient concentrations to the protection of designated 
uses.
    The draft ambient water quality criteria recommendations for lakes 
and reservoirs are based on the available data from the EPA's National 
Lakes Assessment (NLA) survey. The NLA surveys are carried out under 
the EPA's National Aquatic Resource Survey program, which conducts 
water quality and biological surveys of the Nation's surface waters in 
partnerships with state and authorized tribal water quality monitoring 
programs (https://www.epa.gov/national-aquatic-resource-surveys). The 
NLA surveys were designed using random sampling of lakes and reservoirs 
across the United States, and as a result, the data generated represent 
the characteristics of the full population of United States lakes and 
reservoirs. The NLA surveys were implemented using standardized field 
sampling and analytical methods, with internal oversight and 
independent quality control surveillance yielding data of high quality 
and statistical rigor.
    The stressor-response models used in generating the draft ambient 
water quality criteria recommendations are based on previously 
published EPA technical guidance (U.S. EPA 2010, Using stressor-
response relationships to derive numeric nutrient criteria, Office of 
Water, U.S. Environmental Protection Agency, Washington, DC, EPA-820-S-
10-001), as well as scientific peer-reviewed statistical and modeling 
techniques. Models provided in the draft recommended criteria document 
are based on national data, but states and authorized tribes may have 
additional data collected during routine monitoring. Incorporating 
these local data into the national models can refine and improve the 
precision of the estimates of the stressor-response relationships. In 
the appendices of the draft criteria document, the EPA describes case 
studies in which state monitoring data have been combined with national 
data, yielding models that can be used to derive numeric nutrient 
criteria that account for both unique local conditions and national, 
large-scale trends.

IV. What are CWA Section 304(a) recommended water quality criteria?

    CWA Section 304(a) water quality criteria are non-binding 
recommendations developed by the EPA under authority of Section 304(a) 
of the CWA based on the latest scientific information on the effect 
that pollutant concentrations have on aquatic species, recreation, and/
or human health.
    Section 304(a)(1) of the CWA directs the EPA to develop, publish, 
and, from time to time, revise criteria for water quality accurately 
reflecting the latest scientific knowledge. Water quality criteria 
developed under CWA Section 304(a) are based on data and scientific 
judgments on the relationship between pollutant concentrations and 
environmental and human health effects. CWA Section 304(a) recommended 
criteria do not reflect consideration of economic impacts or the 
technological feasibility of meeting pollutant concentrations in 
ambient water.
    CWA Section 304(a) recommended criteria provide non-binding 
guidance to states and authorized tribes in adopting water quality 
standards that ultimately provide a basis for controlling discharges of 
pollutants. Under the CWA and its implementing regulations, states and 
authorized tribes are to adopt water quality criteria to protect 
designated uses (e.g., aquatic life, recreational use). The EPA's water 
quality criteria recommendations are not regulations and do not 
constitute legally binding requirements. States and authorized tribes 
may adopt other scientifically defensible water quality criteria that 
differ from these recommendations. The CWA and its implementing 
regulations require that any new or revised water quality standards 
adopted by the states and authorized tribes be scientifically 
defensible and protective of the designated uses of the bodies of 
water. States and authorized tribes have the flexibility to do this by 
adopting criteria based on (1) the EPA's recommended criteria, (2) the 
EPA's criteria modified to reflect site-specific conditions, or (3) 
other scientifically defensible methods.

V. Use of the Ambient Water Quality Criteria Recommendations for Lakes 
and Reservoirs by States and Authorized Tribes

    The EPA is publishing the draft ambient water quality criteria 
recommendations for lakes and reservoirs for consideration by states 
and authorized tribes as they develop numeric nutrient criteria to 
protect aquatic life, recreation, and drinking water sources from 
nutrient pollution. States and authorized tribes could consider using 
the recommendations, once final, as an alternative to or as a 
supplement of other water quality data and scientifically defensible 
approaches. States and authorized tribes may also modify the criteria 
to reflect site-specific conditions or establish criteria based on 
other scientifically defensible methods (40 CFR 131.11(b)). When 
finalized, these updated CWA Section 304(a) recommended nutrient 
criteria for lakes do not compel a state or authorized tribe to revise 
current EPA approved and adopted criteria, Total Maximum Daily Load 
nutrient load targets, or nitrogen or phosphorus numeric values 
established by other scientifically defensible methods. As part of 
their triennial review, if a state or authorized tribe uses its 
discretion to not adopt new or revised nutrient criteria based on these 
CWA Section 304(a) criteria models, then the state or authorized tribe 
shall provide an explanation when it submits the results of its 
triennial review (40 CFR 131.20(a)).

VI. Solicitation of Scientific Views

    The EPA is soliciting public comment, including, but not limited 
to, additional scientific views, data, and information, regarding the 
science and technical approach used in the derivation of these draft 
ambient water quality criteria recommendations for lakes and 
reservoirs.

David P. Ross,
Assistant Administrator, Office of Water.
[FR Doc. 2020-11126 Filed 5-21-20; 8:45 am]
 BILLING CODE 6560-50-P