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[Federal Register Volume 75, Number 233 (Monday, December 6, 2010)]
[Rules and Regulations]
[Pages 75762-75807]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-29943]

[[Page 75761]]

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Part III

Environmental Protection Agency

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40 CFR Part 131

Water Quality Standards for the State of Florida's Lakes and Flowing 
Waters; Final Rule

Federal Register / Vol. 75 , No. 233 / Monday, December 6, 2010 / 
Rules and Regulations

[[Page 75762]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 131

[EPA-HQ-OW-2009-0596; FRL-9228-7]
RIN 2040-AF11

Water Quality Standards for the State of Florida's Lakes and 
Flowing Waters

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: The Environmental Protection Agency (EPA or Agency) is 
promulgating numeric water quality criteria for nitrogen/phosphorus 
pollution to protect aquatic life in lakes, flowing waters, and springs 
within the State of Florida. These criteria apply to Florida waters 
that are designated as Class I or Class III waters in order to 
implement the State's narrative nutrient provision at Subsection 62-
302-530(47)(b), Florida Administrative Code (F.A.C.), which provides 
that ``[i]n no case shall nutrient concentrations of a body of water be 
altered so as to cause an imbalance in natural populations of aquatic 
flora or fauna.''

DATES: This final rule is effective March 6, 2012, except for 40 CFR 
131.43(e), which is effective February 4, 2011.

ADDRESSES: An electronic version of the public docket is available 
through EPA's electronic public docket and comment system, EPA Dockets. 
You may use EPA Dockets at http://www.regulations.gov to view public 
comments, access the index listing of the contents of the official 
public docket, and to access those documents in the public docket that 
are available electronically. For additional information about EPA's 
public docket, visit the EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm. Although listed in the index, some 
information is not publicly available, i.e., Confidential Business 
Information (CBI) or other information whose disclosure is restricted 
by statute. Certain other material, such as copyright material, is not 
placed on the Internet and will be publicly available only in hard copy 
form. Publicly available docket materials are available either 
electronically in http://www.regulations.gov or in hard copy at the 
Docket Facility. The Office of Water (OW) Docket Center is open from 
8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal 
holidays. The OW Docket Center telephone number is 202-566-1744 and the 
Docket address is OW Docket, EPA West, Room 3334, 1301 Constitution 
Ave., NW., Washington, DC 20004. The Public Reading Room is open from 
8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal 
holidays. The telephone number for the Public Reading Room is (202) 
566-1744.

FOR FURTHER INFORMATION CONTACT: For information concerning this 
rulemaking, contact Danielle Salvaterra, U.S. EPA Headquarters, Office 
of Water, Mailcode: 4305T, 1200 Pennsylvania Avenue, NW., Washington, 
DC 20460; telephone number: 202-564-1649; fax number: 202-566-9981; e-
mail address: salvaterra.danielle@epa.gov.

SUPPLEMENTARY INFORMATION: This supplementary information section is 
organized as follows:

Table of Contents

I. General Information
    A. Executive Summary
    B. Which water bodies are affected by this rule?
    C. What entities may be affected by this rule?
    D. How can I get copies of this document and other related 
information?
II. Background
    A. Nitrogen/Phosphorus Pollution
    B. Statutory and Regulatory Background
    C. Water Quality Criteria
    D. EPA Determination Regarding Florida and EPA's Rulemaking
III. Numeric Criteria for Streams, Lakes, and Springs in the State 
of Florida
    A. General Information
    B. Numeric Criteria for the State of Florida's Streams
    C. Numeric Criteria for the State of Florida's Lakes
    D. Numeric Criterion for the State of Florida's Springs
    E. Applicability of Criteria When Final
IV. Under what conditions will federal standards be withdrawn?
V. Alternative Regulatory Approaches and Implementation Mechanisms
    A. Designating Uses
    B. Variances
    C. Site-Specific Alternative Criteria
    D. Compliance Schedules
    E. Proposed Restoration Water Quality Standard
VI. Economic Analysis
VII. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132 (Federalism)
    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 Advancement Act of 1995
    J. Executive Order 12898 (Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations)
    K. Congressional Review Act

I. General Information

A. Executive Summary

    Florida is known for its abundant and aesthetically beautiful 
natural resources, in particular its water resources. Florida's water 
resources are very important to its economy, for example, its $6.5 
billion fishing industry.\1\ However, nitrogen/phosphorus pollution has 
contributed to severe water quality degradation in the State of 
Florida. Based upon waters assessed and reported by the Florida 
Department of Environmental Protection (FDEP) in its 2008 Integrated 
Water Quality Assessment for Florida, approximately 1,049 miles of 
rivers and streams (about 5% of total assessed streams), 349,248 acres 
of lakes (about 23% of total assessed lakes), and 902 square miles of 
estuaries (about 24% of total assessed estuaries) are known to be 
impaired for nutrients by the State.\2\
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    \1\ Florida Fish and Wildlife Conservation Commission. 2010. The 
economic impact of freshwater fishing in Florida. http://www.myfwc.com/CONSERVATION/Conservation_ValueofConservation_EconFreshwaterImpact.htm. Accessed August 2010.
    \2\ Florida Department of Environmental Protection (FDEP). 2008. 
Integrated Water Quality Assessment for Florida: 2008 305(b) Report 
and 303(d) List Update.
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    The information presented in FDEP's latest water quality assessment 
report, the 2010 Integrated Water Quality Assessment for Florida, 
documents increased identification of assessed waters that are impaired 
due to nutrients. In the FDEP 2010 Integrated Water Quality Assessment 
for Florida, approximately 1,918 miles of rivers and streams (about 8% 
of assessed river and stream miles), 378,435 acres of lakes (about 26% 
of assessed lake acres), and 569 square miles of estuaries \3\ (about 
21% of assessed square miles of estuaries) \4\ are identified as 
impaired by

[[Page 75763]]

nutrients.\5\ The challenge of nitrogen/phosphorus pollution has been 
an ongoing focus for FDEP. Over the past decade or more, FDEP reports 
that it has spent over 20 million dollars collecting and analyzing data 
related to concentrations and impacts of nitrogen/phosphorus pollution 
in the State.\6\ Despite FDEP's intensive efforts to diagnose and 
evaluate nitrogen/phosphorus pollution, substantial and widespread 
water quality degradation from nitrogen/phosphorus over-enrichment has 
continued and remains a significant problem.
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    \3\ The estimated miles for estuaries were recalculated in 2010. 
FDEP used revised GIS techniques to calculate mileages and corrected 
estuary waterbody descriptions by removing land drainage areas that 
had been included in some descriptions, which reduced the estimates 
of total estuarine water area for Florida waters generally, as well 
as for some of the estuary classifications in the 2010 report.
    \4\ For the Integrated Water Quality Assessment for Florida: 
2010 305(b) Report and 303(d) List Update, Florida assessed about 
3,637 additional miles of streams, about 24,833 fewer acres of 
lakes, and about 1,065 fewer square miles of estuaries than the 2008 
Integrated Report. In addition, Florida reevaluated the WBID segment 
boundaries using ``improved GIS techniques'' for mapping. The most 
significant result of the major change in mapping was the reduction 
of assessed estuarine area from 3,726 to 2,661 square miles. The net 
result to the impaired waters for estuaries is that the percent of 
assessed estuaries impaired remains about the same in 2008 (24%) as 
in 2010 (21%).
    \5\ FDEP. 2010. Integrated Water Quality Assessment for Florida: 
2010 305(b) Report and 303(d) List Update.
    \6\ FDEP. 2009. Florida Numeric Nutrient Criteria History and 
Status. http://www.dep.state.fl.us/water/wqssp/nutrients/docs/fl-nnc-summary-100109.pdf. Accessed September 2010.
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    On January 14, 2009, EPA determined under Clean Water Act (CWA) 
section 303(c)(4)(B) that new or revised water quality standards (WQS) 
in the form of numeric water quality criteria are necessary to protect 
the designated uses from nitrogen/phosphorus pollution that Florida has 
set for its Class I and Class III waters. The Agency considered (1) the 
State's documented unique and threatened ecosystems, (2) the large 
number of impaired waters due to existing nitrogen/phosphorus 
pollution, and (3) the challenge associated with growing nitrogen/
phosphorus pollution associated with expanding urbanization, continued 
agricultural development, and a significantly increasing population 
that the U.S. Census estimates is expected to grow over 75% between 
2000 and 2030.\7\ EPA also reviewed the State's regulatory 
accountability system, which represents a synthesis of both technology-
based standards and point source control authority, as well as 
authority to establish enforceable controls for nonpoint source 
activities.
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    \7\ U.S. Census Bureau, Population Division, Interim State 
Population Projections, 2005. http://www.census.gov/population/projections/SummaryTabA1.pdf.
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    A significant challenge faced by Florida's water quality program is 
its dependence and current reliance upon an approach involving 
resource-intensive and time-consuming site-by-site data collection and 
analysis to interpret non-numeric narrative criteria. This approach is 
used to make water quality impairment determinations under CWA section 
303(d), to set appropriately protective numeric nitrogen and phosphorus 
pollution targets to guide restoration of impaired waters, and to 
establish numeric nitrogen and phosphorus goals to ensure effective 
protection and maintenance of non-impaired waters. EPA determined that 
Florida's reliance on a case-by-case interpretation of its narrative 
criterion in implementing an otherwise comprehensive water quality 
framework of enforceable accountability mechanisms was insufficient to 
ensure protection of applicable designated uses under Subsection 62-
302.530(47)(b), F.A.C., which, as noted above, provides ``[i]n no case 
shall nutrient concentrations of a body of water be altered so as to 
cause an imbalance in natural populations of aquatic flora or fauna.''
    In accordance with the terms of EPA's January 14, 2009 
determination, an August 2009 Consent Decree, and June 7, 2010 and 
October 27, 2010 revisions to that Consent Decree, which are discussed 
in more detail in Section II.D, EPA is promulgating and establishing 
final numeric criteria for lakes and springs throughout Florida, and 
flowing waters (e.g., rivers, streams, canals, etc.) located outside of 
the South Florida Region.\8\
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    \8\ For purposes of this rule, EPA has distinguished South 
Florida as those areas south of Lake Okeechobee and the 
Caloosahatchee River watershed to the west of Lake Okeechobee and 
the St. Lucie watershed to the east of Lake Okeechobee, hereinafter 
referred to as the South Florida Region. Numeric criteria applicable 
to flowing waters in the South Florida Region will be addressed in 
the second phase of EPA's rulemaking regarding the establishment of 
estuarine and coastal numeric criteria. (Please refer to Section I.B 
for a discussion of the water bodies affected by this rule).
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    Regarding numeric criteria for streams, the Agency conducted a 
detailed technical evaluation of the substantial amount of sampling, 
monitoring and associated water quality analytic data available on 
Florida streams together with a significant amount of related 
scientific analysis. EPA concluded that reliance on a reference-based 
methodology was a strong and scientifically sound approach for deriving 
numeric criteria, in the form of total nitrogen (TN) and total 
phosphorus (TP) concentration values for flowing waters including 
streams and rivers. This information is presented in more detail in 
Section III.B below.
    For lakes, EPA is promulgating a classification approach using 
color and alkalinity based upon substantial data that show that lake 
color and alkalinity are important predictors of the degree to which TN 
and TP concentrations result in a biological response such as elevated 
chlorophyll a levels. EPA found that correlations between nitrogen/
phosphorus and biological response parameters in the different types of 
lakes in Florida were specific, significant, and documentable, and when 
considered in combination with additional lines of evidence, support a 
stressor-response approach to criteria development for Florida's lakes. 
EPA's results show a significant relationship between concentrations of 
nitrogen and phosphorus in lakes and algal growth. The Agency is also 
promulgating an accompanying supplementary analytical approach that the 
State can use to adjust TN and TP criteria within a certain range for 
individual lakes where sufficient data on long-term ambient chlorophyll 
a, TN, and TP levels are available to demonstrate that protective 
chlorophyll a criterion for a specific lake will still be maintained 
and attainment of the designated use will be assured. This information 
is presented in more detail in Section III.C below.
    EPA also evaluated what downstream protection criteria for streams 
that flow into lakes is necessary for assuring the protection of 
downstream lake water quality pursuant to the provisions of 40 CFR 
130.10(b), which requires that water quality standards (WQS) must 
provide for the attainment and maintenance of the WQS of downstream 
waters. EPA examined a variety of lake modeling techniques and data to 
ensure protection of aquatic life in downstream lakes that have streams 
flowing into them. Accordingly, this final rule includes a tiered 
approach to adjust instream TP and TN criteria for flowing waters to 
ensure protection of downstream lakes. This approach is detailed in 
Section III.C(2)(f) below.\9\
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    \9\ As provided by the terms of the June 7, 2010 amended Consent 
Decree, downstream protection values for estuaries and coastal 
waters will be addressed in the context of the second phase of this 
rulemaking process.
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    Regarding numeric criteria for springs, EPA is promulgating a 
nitrate+nitrite criterion for springs based on stressor-response 
relationships that are based on laboratory data and field evaluations 
that document the response of nuisance \10\ algae and periphyton growth 
to nitrate+nitrite concentrations in springs. This criterion is 
explained in more detail in Section III.D below.
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    \10\ Nuisance algae is best characterized by Subsection 62-
302.200(17), F.A.C.: ``Nuisance Species'' shall mean species of 
flora or fauna whose noxious characteristics or presence in 
sufficient number, biomass, or areal extent may reasonably be 
expected to prevent, or unreasonably interfere with, a designated 
use of those waters.
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    Finally, EPA is promulgating in this notice an approach to 
authorize and allow derivation of Federal site-specific alternative 
criteria (SSAC) based upon EPA review and approval of applicant 
submissions of scientifically defensible

[[Page 75764]]

recalculations that meet the requirements of CWA section 303(c) and 
EPA's implementing regulations at 40 CFR part 131. Total maximum daily 
load (TMDL) targets submitted to EPA for consideration as new or 
revised WQS would be reviewed under this SSAC process. This approach is 
discussed in more detail in Section V.C below.
    Throughout the development of this rulemaking, EPA has emphasized 
the importance of sound science and widespread input in developing 
numeric criteria. Stakeholders have reiterated that numeric criteria 
must be scientifically sound. As demonstrated by the extent and detail 
of scientific analysis explained below, EPA continues to strongly 
agree. Under the CWA and EPA's implementing regulations, numeric 
criteria must protect the designated use of a waterbody (as well as 
ensure protection of downstream uses) and must be based on sound 
scientific rationale. (See CWA section 303(c); 40 CFR 131.11). In 
Florida, EPA relied upon its published criteria development 
methodologies \11\ and a substantial body of scientific analysis, 
documentation, and evaluation, much of it provided to EPA by FDEP. As 
discussed in more detail below, EPA believes that the final criteria in 
this rule meet requirements for designated use and downstream WQS 
protection under the CWA and that they are clearly based on sound and 
substantial data and analyses.
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    \11\ USEPA. 2000a. Nutrient Criteria Technical Guidance Manual: 
Lakes and Reserviors. EPA-822-B-00-001. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC. USEPA. 2000b. 
Nutrient Criteria Technical Guidance Manual: Rivers and Streams. 
EPA-822-B-00-002. U.S. Environmental Protection Agency, Office of 
Water, Washington, DC.
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B. Which water bodies are affected by this rule?

    The criteria in this final rulemaking apply to a group of inland 
waters of the United States within Florida. Specifically, as defined 
below, these criteria apply to lakes and springs throughout Florida, 
and flowing waters (e.g., rivers, streams, canals, etc.) located 
outside of the South Florida Region. For purposes of this rule, EPA has 
distinguished South Florida as those areas south of Lake Okeechobee and 
the Caloosahatchee River watershed to the west of Lake Okeechobee and 
the St. Lucie watershed to the east of Lake Okeechobee, hereinafter 
referred to as the South Florida Region. In this section, EPA defines 
the water bodies affected by this rule with respect to the Clean Water 
Act, Florida Administrative Code, and geographic scope in Florida. 
Because this regulation applies to inland waters, EPA defines fresh 
water as it applies to the affected water bodies.
    The CWA requires adoption of WQS for ``navigable waters.'' CWA 
section 303(c)(2)(A). The CWA defines ``navigable waters'' to mean 
``the waters of the United States, including the territorial seas.'' 
CWA section 502(7). Whether a particular waterbody is a water of the 
United States is a waterbody-specific determination. Every waterbody 
that is a water of the United States requires WQS under the CWA. EPA is 
not aware of any waters of the United States in Florida that are 
currently exempted from the State's WQS. For any privately-owned water 
in Florida that is a water of the United States, the applicable numeric 
criteria for those types of waters would apply. This rule does not 
apply to waters for which the Miccosukee Tribe of Indians or Seminole 
Tribe of Indians has obtained Treatment in the Same Manner as a State 
status for Sections 303 and 401 of the CWA, pursuant to Section 518 of 
the CWA.
    EPA's final rule defines ``lakes and flowing waters'' (a phrase 
that includes lakes, streams, and springs) to mean inland surface 
waters that have been classified as Class I (Potable Water Supplies) or 
Class III (Recreation, Propagation and Maintenance of a Healthy, Well-
Balanced Population of Fish and Wildlife) water bodies pursuant to 
Section 62-302.400, F.A.C., which are predominantly fresh waters, 
excluding wetlands. Class I and Class III surface waters share water 
quality criteria established to ``protect recreation and the 
propagation and maintenance of a healthy, well-balanced population of 
fish and wildlife'' pursuant to Subsection 62-302.400(4), F.A.C.\12\
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    \12\ Class I waters also include an applicable nitrate limit of 
10 mg/L and nitrite limit of 1 mg/L for the protection of human 
health in drinking water supplies. The nitrate limit applies at the 
entry point to the distribution system (i.e., after any treatment); 
see Chapter 62-550, F.A.C., for additional details.
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    Geographically, the regulation applies to all lakes and springs 
throughout Florida. EPA is not finalizing numeric criteria for 
Florida's streams or canals in south Florida at this time. As noted 
above, EPA has distinguished South Florida as those areas south of Lake 
Okeechobee and the Caloosahatchee River watershed to the west of Lake 
Okeechobee and the St. Lucie watershed to the east of Lake Okeechobee, 
hereinafter referred to as the South Florida Region. The Agency will 
propose criteria for south Florida flowing waters in conjunction with 
criteria for Florida's estuarine and coastal waters by November 14, 
2011.
    Consistent with Section 62-302.200, F.A.C., EPA's final rule 
defines ``predominantly fresh waters'' to mean surface waters in which 
the chloride concentration at the surface is less than 1,500 milligrams 
per liter (mg/L). Consistent with Section 62-302.200, F.A.C., EPA's 
final rule defines ``surface water'' to mean ``water upon the surface 
of the earth, whether contained in bounds created naturally, 
artificially, or diffused. Water from natural springs shall be 
classified as surface water when it exits from the spring onto the 
earth's surface.'' In this rulemaking, EPA is promulgating numeric 
criteria for the following waterbody types: lakes, streams, and 
springs. EPA's final rule also includes definitions for each of these 
waters. ``Lake'' means a slow-moving or standing body of freshwater 
that occupies an inland basin that is not a stream, spring, or wetland. 
``Stream'' means a free-flowing, predominantly fresh surface water in a 
defined channel, and includes rivers, creeks, branches, canals, 
freshwater sloughs, and other similar water bodies. ``Spring'' means a 
site at which ground water flows through a natural opening in the 
ground onto the land surface or into a body of surface water. 
Consistent with Section 62-312.020, F.A.C., ``canal'' means a trench, 
the bottom of which is normally covered by water with the upper edges 
of its two sides normally above water.

C. What entities may be affected by this rule?

    Citizens concerned with water quality in Florida may be interested 
in this rulemaking. Entities discharging nitrogen or phosphorus to 
lakes and flowing waters of Florida could be indirectly affected by 
this rulemaking because WQS are used in determining National Pollutant 
Discharge Elimination System (NPDES) permit limits. Categories and 
entities that may ultimately be affected include:

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                                      Examples of potentially affected
             Category                             entities
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Industry.........................  Industries discharging pollutants to
                                    lakes and flowing waters in the
                                    State of Florida.
Municipalities...................  Publicly-owned treatment works
                                    discharging pollutants to lakes and
                                    flowing waters in the State of
                                    Florida.
Stormwater Management Districts..  Entities responsible for managing
                                    stormwater runoff in Florida.
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    This table is not intended to be exhaustive, but rather provides a 
guide for entities that may be directly or indirectly affected by this 
action. This table lists the types of entities of which EPA is now 
aware that potentially could be affected by this action. Other types of 
entities not listed in the table, such as nonpoint source contributors 
to nitrogen/phosphorus pollution in Florida's waters may be affected 
through implementation of Florida's water quality standards program 
(i.e., through Basin Management Action Plans (BMAPs)). Any parties or 
entities conducting activities within watersheds of the Florida waters 
covered by this rule, or who rely on, depend upon, influence, or 
contribute to the water quality of the lakes and flowing waters of 
Florida, may be affected by this rule. To determine whether your 
facility or activities may be affected by this action, you should 
carefully examine the language in 40 CFR 131.43, which is the final 
rule. If you have questions regarding the applicability of this action 
to a particular entity, consult the person listed in the preceding FOR 
FURTHER INFORMATION CONTACT section.

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

    1. Docket. EPA has established an official public docket for this 
action under Docket Id. No. EPA-HQ-OW-2009-0596. The official public 
docket consists of the document specifically referenced in this action, 
any public comments received, and other information related to this 
action. Although a part of the official docket, the public docket does 
not include CBI or other information whose disclosure is restricted by 
statute. The official public docket is the collection of materials that 
is available for public viewing at the OW Docket, EPA West, Room 3334, 
1301 Constitution Ave., NW., Washington, DC 20004. This Docket Facility 
is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding 
legal holidays. The Docket telephone number is 202-566-2426. A 
reasonable fee will be charged for copies.
    2. Electronic Access. You may access this Federal Register document 
electronically through the EPA Internet under the ``Federal Register'' 
listings at http://www.epa.gov/fedrgstr/.
    An electronic version of the public docket is available through 
EPA's electronic public docket and comment system, EPA Dockets. You may 
use EPA Dockets at http://www.regulations.gov to view public comments, 
access the index listing of the contents of the official public docket, 
and to access those documents in the public docket that are available 
electronically. For additional information about EPA's public docket, 
visit the EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm. Although not all docket materials may be available 
electronically, you may still access any of the publicly available 
docket materials through the Docket Facility identified in Section 
I.C(1).

II. Background

A. Nitrogen/Phosphorus Pollution

1. What is nitrogen/phosphorus pollution?
    Excess loading of nitrogen and phosphorus compounds,\13\ is one of 
the most prevalent causes of water quality impairment in the United 
States. Nitrogen/phosphorus pollution problems have been recognized for 
some time in the U.S., for example a 1969 report by the National 
Academy of Sciences \14\ notes ``[t]he pollution problem is critical 
because of increased population, industrial growth, intensification of 
agricultural production, river-basin development, recreational use of 
waters, and domestic and industrial exploitation of shore properties. 
Accelerated eutrophication causes changes in plant and animal life--
changes that often interfere with use of water, detract from natural 
beauty, and reduce property values.'' Inputs of nitrogen and phosphorus 
lead to over-enrichment in many of the Nation's waters and constitute a 
widespread, persistent, and growing problem. Nitrogen/phosphorus 
pollution in fresh water systems can significantly impact aquatic life 
and long-term ecosystem health, diversity, and balance. More 
specifically, high nitrogen and phosphorus loadings result in harmful 
algal blooms (HABs), reduced spawning grounds and nursery habitats, 
fish kills, and oxygen-starved hypoxic or ``dead'' zones. Public health 
concerns related to nitrogen/phosphorus pollution include impaired 
surface and groundwater drinking water sources from high levels of 
nitrates, possible formation of disinfection byproducts in drinking 
water, and increased exposure to toxic microbes such as 
cyanobacteria.15 16 Degradation of water bodies from 
nitrogen/phosphorus pollution can result in economic consequences. For 
example, given that fresh and salt water fishing in Florida are 
significant recreational and tourist attractions generating over six 
billion dollars annually,\17\ changes in Florida's waters that degrade 
water quality to the point that sport fishing populations are affected, 
will also affect this important part of Florida's economy. Elevated 
nitrogen/phosphorus levels can occur locally in a stream or 
groundwater, or can accumulate much further downstream leading to 
degraded lakes, reservoirs, and estuaries where fish and aquatic life 
can no longer survive.
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    \13\ To be used by living organisms, nitrogen gas must be fixed 
into its reactive forms; for plants, either nitrate or ammonia 
(Boyd, C.E. 1979. Water Quality in Warmwater Fish Ponds. Auburn 
University: Alabama Agricultural Experiment Station, Auburn, AL). 
Eutrophication is defined as the natural or artificial addition of 
nitrogen/phosphorus to bodies of water and to the effects of added 
nitrogen/phosphorus (National Academy of Sciences (U.S.). 1969. 
Eutrophication: Causes, Consequences, Correctives. National Academy 
of Sciences, Washington, DC.)
    \14\ National Academy of Sciences (U.S.). 1969. Eutrophication: 
Causes, Consequences, Correctives. National Academy of Sciences, 
Washington, DC.
    \15\ Villanueva, C.M. et al., 2006. Bladder Cancer and Exposure 
to Water Disinfection By-Products through Ingestion, Bathing, 
Showering, and Swimming in Pools. American Journal of Epidemiology 
165(2):148-156.
    \16\ USEPA. 2009. What is in Our Drinking Water?. United States 
Environmental Protection Agency, Office of Research and Development. 
http://www.epa.gov/extrmurl/research/process/drinkingwater.html. 
Accessed December 2009.
    \17\ Florida Fish and Wildlife Conservation Commission. 2010. 
The economic impact of freshwater fishing in Florida. http://www.myfwc.com/CONSERVATION/Conservation_ValueofConservation_EconFreshwaterImpact.htm. Accessed August 2010.
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    Excess nitrogen/phosphorus in water bodies comes from many sources, 
which can be grouped into five major categories: (1) Urban stormwater 
runoff--sources associated with urban land use and development, (2) 
municipal and industrial waste water discharges, (3) row crop 
agriculture, (4) livestock production, and (5) atmospheric deposition 
from the production of nitrogen oxides in electric

[[Page 75766]]

power generation and internal combustion engines. These sources 
contribute significant loadings of nitrogen and phosphorus to surface 
waters, causing major impacts to aquatic ecosystems and significant 
imbalances in the natural populations of flora and 
fauna.18 19
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    \18\ National Research Council. 2000. Clean coastal waters: 
Understanding and reducing the effects of nutrient pollution. 
National Academies Press, Washington, DC; Howarth, R.W., A. 
Sharpley, and D. Walker. 2002. Sources of nutrient pollution to 
coastal waters in the United States: Implications for achieving 
coastal water quality goals. Estuaries 25(4b):656-676; Smith, V.H. 
2003. Eutrophication of freshwater and coastal marine ecosystems. 
Environmental Science and Pollution Research 10(2):126-139; Dodds, 
W.K., W.W. Bouska, J.L. Eitzmann, T.J. Pilger, K.L. Pitts, A.J. 
Riley, J.T. Schloesser, and D.J. Thornbrugh. 2009. Eutrophication of 
U.S. freshwaters: Analysis of potential economic damages. 
Environmental Science and Technology 43(1):12-19.
    \19\ State-EPA Nutrient Innovations Task Group. 2009. An Urgent 
Call to Action: Report of the State-EPA Nutrient Innovations Task 
Group.
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2. Adverse Impacts of Nitrogen/Phosphorus Pollution on Aquatic Life, 
Human Health, and the Economy
    Fish, shellfish, and wildlife require clean water for survival. 
Changes in the environment resulting from elevated nitrogen/phosphorus 
levels (such as algal blooms, toxins from harmful algal blooms, and 
hypoxia/anoxia) can cause a variety of effects. The causal pathways 
that lead from human activities to excess nutrients to impacts on 
designated uses in lakes and streams are well established in the 
scientific literature (e.g., Streams: Stockner and Shortreed 1976, 
Stockner and Shortreed 1978, Elwood et al. 1981, Horner et al. 1983, 
Bothwell 1985, Peterson et al. 1985, Moss et al. 1989, Dodds and Gudder 
1992, Rosemond et al. 1993, Bowling and Baker 1996, Bourassa and 
Cattaneo 1998, Francoeur 2001, Biggs 2000, Rosemond et al. 2001, 
Rosemond et al. 2002, Slavik et al. 2004, Cross et al. 2006, Mulholland 
and Webster 2010; Lakes: Vollenweider 1968, NAS 1969, Schindler et al. 
1973, Schindler 1974, Vollenweider 1976, Carlson 1977, Paerl 1988, 
Elser et al. 1990, Smith et al. 1999, Downing et al. 2001, Smith et al. 
2006, Elser et al. 2007).\20\
---------------------------------------------------------------------------

    \20\ For Streams:
    Stockner, J.G., and K.R.S. Shortreed. 1976. Autotrophic 
production in Carnation Creek, a coastal rainforest stream on 
Vancouver Island, British Columbia. Journal of the Fisheries 
Research Board of Canada 33:1553-1563.;
    Stockner, J.G., and K.R.S. Shortreed. 1978. Enhancement of 
autotrophic production by nutrient addition in a coastal rainforest 
stream on Vancouver Island. Journal of the Fisheries Research Board 
of Canada 35:28-34.;
    Elwood, J.W., J.D. Newbold, A.F. Trimble, and R.W. Stark. 1981. 
The limiting role of phosphorus in a woodland stream ecosystem: 
effects of P enrichment on leaf decomposition and primary producers. 
Ecology 62:146-158.;
    Horner, R.R., E.B. Welch, and R.B. Veenstra. 1983. Development 
of nuisance periphytic algae in laboratory streams in relation to 
enrichment and velocity. Pages 121-134 in R.G. Wetzel (editor). 
Periphyton of freshwater ecosystems. Dr. W. Junk Publishers, The 
Hague, The Netherlands.;
    Bothwell, M.L. 1985. Phosphorus limitation of lotic periphyton 
growth rates: an intersite comparison using continuous-flow troughs 
(Thompson River system, British Columbia). Limnology and 
Oceanography 30:527-542.;
    Peterson, B.J., J.E. Hobbie, A.E. Hershey, M.A. Lock, T.E. Ford, 
J.R. Vestal, V.L. McKinley, M.A.J. Hullar, M.C. Miller, R.M. 
Ventullo, and G.S. Volk. 1985. Transformation of a tundra river from 
heterotrophy to autotrophy by addition of phosphorus. Science 
229:1383-1386.;
    Moss, B., I. Hooker, H. Balls, and K. Manson. 1989. 
Phytoplankton distribution in a temperate floodplain lake and river 
system. I. Hydrology, nutrient sources and phytoplankton biomass. 
Journal of Plankton Research 11:813-835.;
    Dodds, W.K., and D.A. Gudder. 1992. The ecology of Cladophora. 
Journal of Phycology 28:415-427.; Rosemond, A. D., P. J. Mulholland, 
and J. W. Elwood. 1993. Top-down and bottom-up control of stream 
periphyton: Effects of nutrients and herbivores. Ecology 74:1264-
1280.;
    Bowling, L.C., and P.D. Baker. 1996. Major cyanobacterial bloom 
in the Barwon-Darling River, Australia, in 1991, and underlying 
limnological conditions. Marine and Freshwater Research 47: 643-
657.;
    Bourassa, N., and A. Cattaneo. 1998. Control of periphyton 
biomass in Laurentian streams (Quebec). Journal of the North 
American Benthological Society 17:420-429.;
    Francoeur, S.N. 2001. Meta-analysis of lotic nutrient amendment 
experiments: detecting and quantifying subtle responses. Journal of 
the North American Benthological Society 20:358-368.;
    Biggs, B.J.F. 2000. Eutrophication of streams and rivers: 
dissolved nutrient-chlorophyll relationships for Benthic algae. 
Journal of the North American Benthological Society 19:17-31.;
    Rosemond, A.D., C.M. Pringle, A. Ramirez, and M.J. Paul. 2001. A 
test of top-down and bottom-up control in a detritus-based food web. 
Ecology 82: 2279-2293.;
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    When excessive nitrogen/phosphorus loads change a waterbody's algae 
and plant species, the change in habitat and available food resources 
can induce changes affecting an entire food chain. Algal blooms block 
sunlight that submerged grasses need to grow, leading to a decline of 
submerged aquatic vegetation beds and decreased habitat for juvenile 
organisms. Algal blooms can also increase turbidity and impair the 
ability of fish and other aquatic life to find food.\21\ Algae can also 
damage or clog the gills of fish and invertebrates.\22\ Excessive algal 
blooms (those that use oxygen for respiration during periods without 
sunlight) can lead to diurnal shifts in a waterbody's production and 
consumption of dissolved oxygen (DO) resulting in reduced DO levels 
that are sufficiently low to harm or kill important recreational 
species such as largemouth bass.
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    Rosemond, A.D., C.M. Pringle, A. Ramirez, M.J. Paul, and J.L. 
Meyer. 2002. Landscape variation in phosphorus concentration and 
effects on detritus-based tropical streams. Limnology and 
Oceanography 47:278-289.;
    Slavik, K., B.J. Peterson, L.A. Deegan, W.B. Bowden, A.E. 
Hershey, and J.E. Hobbie. 2004. Long-term responses of the Kuparuk 
River ecosystem to phosphorus fertilization. Ecology 85:939--954.;
    Cross, W.F., J.B. Wallace, A.D. Rosemond, and S.L. Eggert. 2006. 
Whole-system nutrient enrichment Increases secondary production in a 
detritus-based ecoystem. Ecology 87:1556-1565.;
    Mulholland, P.J. and J.R. Webster. 2010. Nutrient dynamics in 
streams and the role of J-NABS. Journal of the North American 
Benthological Society 29:100-117.;
    For Lakes:
    Vollenweider, R.A. 1968. Scientific Fundamentals of the 
Eutrophication of Lakes and Flowing Waters, With Particular 
Reference to Nitrogen and Phosphorus as Factors in Eutrophication 
(Tech Rep DAS/CS/68.27, OECD, Paris).;
    National Academy of Science. 1969. Eutrophication: Causes, 
Consequences, Correctives. National Academy of Science, Washington, 
DC.;
    Schindler D.W., H. Kling, R.V. Schmidt, J. Prokopowich, V.E. 
Frost, R.A. Reid, and M. Capel. 1973. Eutrophication of Lake 227 by 
addition of phosphate and nitrate: The second, third, and fourth 
years of enrichment 1970, 1971, and 1972. Journal of the Fishery 
Research Board of Canada 30:1415-1440.;
    Schindler D.W. 1974. Eutrophication and recovery in experimental 
lakes: Implications for lake management. Science 184:897-899.;
    Vollenweider, R.A. 1976. Advances in Defining Critical Loading 
Levels for Phosphorus in Lake Eutrophication. Memorie dell'Istituto 
Italiano di Idrobiologia 33:53-83.;
    Carlson R.E. 1977. A trophic State index for lakes. Limnology 
and Oceanography 22:361-369.;
    Paerl, H.W. 1988. Nuisance phytoplankton blooms in coastal, 
estuarine, and inland waters. Limnology and Oceanography 33:823-
847.;
    Elser, J.J., E.R. Marzolf, and C.R. Goldman. 1990. Phosphorus 
and nitrogen limitation of phytoplankton growth in the freshwaters 
of North America: a review and critique of experimental enrichments. 
Canadian Journal of Fisheries and Aquatic Science 47:1468-1477.;
    Smith, V.H., G.D. Tilman, and J.C. Nekola. 1999. Eutrophication: 
impacts of excess nutrient inputs on freshwater, marine, and 
terrestrial ecosystems. Environmental Pollution 100:179-196.;
    Downing, J.A., S.B. Watson, and E. McCauley. 2001. Predicting 
cyanobacteria dominance in lakes. Canadian Journal of Fisheries and 
Aquatic Sciences 58:1905-1908.;
    Smith, V.H., S.B. Joye, and R.W. Howarth. 2006. Eutrophication 
of freshwater and marine ecosystems. Limnology and Oceanography 
51:351-355.;
    Elser, J.J., M.E.S. Bracken, E.E. Cleland, D.S. Gruner, W.S. 
Harpole, H. Hillebrand, J.T. Ngai, E.W. Seabloom, J.B. Shurin, and 
J.E. Smith. 2007. Global analysis of nitrogen and phosphorus 
limitation of primary production in freshwater, marine, and 
terrestrial ecosystems. Ecology Letters 10:1135-1142.
    \21\ Hauxwell, J., C. Jacoby, T. Frazer, and J. Stevely. 2001. 
Nutrients and Florida's Coastal Waters: Florida Sea Grant Report No. 
SGEB-55. Florida Sea Grant College Program, University of Florida, 
Gainesville, FL.
    \22\ NOAA. 2009. Harmful Algal Blooms: Current Programs 
Overview. National Oceanic and Atmospheric Administration. http://www.cop.noaa.gov/stressors/extremeevents/hab/default.aspx. Accessed 
December 2009.
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    Excessive algal growth also contributes to increased oxygen 
consumption associated with decomposition (e.g. decaying vegetative 
matter), in many instances reducing

[[Page 75767]]

oxygen to levels below that needed for aquatic life to survive and 
flourish.23 24 Mobile species, such as adult fish, can 
sometimes survive by moving to areas with more oxygen. However, 
migration to avoid hypoxia depends on species mobility, availability of 
suitable habitat, and adequate environmental cues for migration. Less 
mobile or immobile species, such as mussels, cannot move to avoid low 
oxygen and are often killed during hypoxic events.\25\ While certain 
mature aquatic animals can tolerate a range of dissolved oxygen levels 
that occur in the water, younger life stages of species like fish and 
shellfish often require higher levels of oxygen to survive.\26\ 
Sustained low levels of dissolved oxygen cause a severe decrease in the 
amount of aquatic life in hypoxic zones and affect the ability of 
aquatic organisms to find necessary food and habitat.
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    \23\ NOAA. 2009. Harmful Algal Blooms: Current Programs 
Overview. National Oceanic and Atmospheric Administration. http://www.cop.noaa.gov/stressors/extremeevents/hab/default.aspx. Accessed 
December 2009.
    \24\ USGS. 2009. Hypoxia. U.S. Geological Survey. http://toxics.usgs.gov/definitions/hypoxia.html. Accessed December 2009.
    \25\ ESA. 2009. Hypoxia. Ecological Society of America. http://www.esa.org/education_diversity/pdfDocs/hypoxia.pdf. Accessed 
December 2009.
    \26\ USEPA. 1986. Ambient Water Quality Criteria for Dissolved 
Oxygen Freshwater Aquatic Life. EPA-800-R-80-906. Environmental 
Protection Agency, Office of Water, Washington DC.
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    In freshwater, HABs including, for example, blue-green algae from 
the phylum of bacteria called cyanobacteria,\27\ can produce toxins 
that have been implicated as the cause of a number of fish and bird 
mortalities.\28\ These toxins have also been tied to the death of pets 
and livestock that may be exposed through drinking contaminated water 
or grooming themselves after bodily exposure.\29\ Many other States, 
and countries for that matter, are experiencing problems with algal 
blooms.\30\ Ohio on September 3, 2010,\31\ for example, listed eight 
water bodies as ``Bloom Advisory,'' \32\ six water bodies as ``Toxin 
Advisory,'' \33\ and two waters as ``No Contact Advisory.'' \34\ 
Species of cyanobacteria associated with freshwater algal blooms 
include: Microcystis aeruginosa, Anabaena circinalis, Anabaena flos-
aquae, Aphanizomenon flos-aquae, and Cylindrospermopsis raciborskii. 
The toxins from cyanobacterial harmful algal blooms can produce 
neurotoxins (affect the nervous system), hepatotoxins (affect the 
liver), produce lipopolysaccharides that affect the gastrointestinal 
system, and some are tumor promoters.\35\ A recent study showed that at 
least one type of cyanobacteria has been linked to cancer and tumor 
growth in animals.\36\ Cyanobacteria toxins can also pass through 
normal drinking water treatment processes and pose an increased risk to 
humans or animals.\37\
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    \27\ CDC. 2010. Facts about cyanobacteria and cyanobacterial 
harmful algal blooms. Centers for Disease Control and Prevention. 
http://www.cdc.gov/hab/cyanobacteria/facts.htm. Accessed August 
2010.
    \28\ Ibelings, Bas W. and Karl E. Havens. 2008 Chapter 32: 
Cyanobacterial toxins: a qualitative meta-analysis of 
concentrations, dosage and effects in freshwater, estuarine and 
marine biota. In Cyanobacterial Harmful Algal Blooms: State of the 
Science and Research Needs. From the Monograph of the September 6-
10, 2005 International Symposium on Cyanobacterial Harmful Algal 
Blooms (ISOC-HAB) in Durham, NC. http://www.epa.gov/cyano_habs_symposium/monograph/Ch32.pdf. Accessed August 19, 2010.
    \29\ WHOI. 2008. HAB Impacts on Wildlife. Woods Hole 
Oceanographic Institution. http://www.whoi.edu/redtide/page.do?pid=9682. Accessed December 2009.
    \30\ FDEP. 2010. Blue Green Algae Frequently Asked Questions. 
http://www.dep.state.fl.us/water/bgalgae/faq.htm. Accessed August 
2010.
    \31\ Ohio DNR. 2010. News Release September 3, 2010. http://www.epa.state.oh.us/portals/47/nr/2010/september/9-3samplingresults.pdf. Accessed September 2010.
    \32\ Defined as: Cautionary advisory to avoid contact with any 
algae. Ohio DNR. 2010. News Release September 3, 2010. http://www.epa.state.oh.us/portals/47/nr/2010/september/9-3samplingresults.pdf. Accessed September 2010.
    \33\ Defined as: Avoid contact with any algae and direct contact 
with water. Ohio DNR. 2010. News Release September 3, 2010. http://www.epa.state.oh.us/portals/47/nr/2010/september/9-3samplingresults.pdf. Accessed September 2010.
    \34\ Defined as: Avoid any and all contact with or ingestion of 
the lake water. This includes the launching of any watercraft on the 
lake. Ohio DNR. 2010. News Release September 3, 2010. http://www.epa.state.oh.us/portals/47/nr/2010/september/9-3samplingresults.pdf. Accessed September 2010.
    \35\ CDC. 2010. Facts about cyanobacteria and cyanobacterial 
harmful algal blooms, Centers for Disease Control and Prevention. 
http://www.cdc.gov/hab/cyanobacteria/facts.htm. Accessed August 
2010.
    \36\ Falconer, I.R., and A.R. Humpage. 2005. Health Risk 
Assessment of Cyanobacterial (Blue-green Algal) Toxins in Drinking 
Water. International Journal of Research and Public Health 2(1): 43-
50.
    \37\ Carmichael, W.W. 2000. Assessment of Blue-Green Algal 
Toxins in Raw and Finished Drinking Water. AWWA Research Foundation, 
Denver, CO.
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    Health and recreational use impacts to humans result directly from 
exposure to elevated nitrogen/phosphorus pollution levels and 
indirectly from the subsequent waterbody changes that occur from 
increased nitrogen/phosphorus pollution (such as algal blooms and 
toxins). Direct impacts include effects to human health through 
potentially contaminated drinking water. Indirect impacts include 
restrictions on recreation (such as boating and swimming). Algal blooms 
can prevent opportunities to swim and engage in other types of 
recreation. In areas where recreation is determined to be unsafe 
because of algal blooms, warning signs are often posted to discourage 
human use of the waters.
    Nitrate in drinking water can cause serious health problems for 
humans,\38\ especially infants. EPA developed a Maximum Contaminant 
Level (MCL) of 10 mg/L for nitrate in drinking water.\39\ In the 2010 
USGS National Water-Quality Assessment Program report, nitrate was 
found to be the most frequently detected nutrient in streams at 
concentrations greater than 10 mg/L. The report also found that 
concentrations of nitrate greater than the MCL of 10 mg/L were more 
prevalent and widespread in groundwater used for drinking water than in 
streams.\40\ Florida has adopted EPA's recommendations for the nitrate 
MCL in Florida's regulated drinking water systems and a 10 mg/L 
criteria for nitrate in Class I waters. FDEP shares EPA's concern 
regarding blue-baby syndrome as can be seen in information FDEP reports 
on its drinking water information for the public: ``Nitrate is used in 
fertilizer and is found in sewage and wastes from human and/or farm 
animals and generally gets into drinking water from those activities. 
Excessive levels of nitrate in drinking water have caused serious 
illness and sometimes death in infants less than six months of age \41\ 
* * * EPA has set the drinking water standard at 10 parts per million 
(ppm) [or 10 mg/L] for nitrate to protect

[[Page 75768]]

against the risk of these adverse effects \42\ * * * Drinking water 
that meets the EPA standard is associated with little to none of this 
risk and is considered safe with respect to nitrate.'' \43\
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    \38\ For more information, refer to Manassaram, Deana M., 
Lorraine C. Backer, and Deborah M. Moll. 2006. A Review of Nitrates 
in Drinking Water: Maternal Exposure and Adverse Reproductive and 
Developmental Outcomes. Environmental Health Perspect. 114(3): 320-
327.
    \39\ USEPA. 2007. Nitrates and Nitrites: TEACH Chemical Summary. 
U.S. Environmental Protection Agency. http://www.epa.gov/teach/chem_summ/Nitrates_summary.pdf. Accessed December 2009.
    \40\ Dubrovsky, N.M., Burow, K.R., Clark, G.M., Gronberg, J.M., 
Hamilton P.A., Hitt, K.J., Mueller, D.K., Munn, M.D., Nolan, B.T., 
Puckett, L.J., Rupert, M.G., Short, T.M., Spahr, N.E., Sprague, 
L.A., and Wilber, W.G. 2010. The quality of our Nation's waters--
Nutrients in the Nation's streams and groundwater, 1992-2004: U.S. 
Geological Survey Circular 1350, 174p. Available electronically at: 
http://water.usgs.gov/nawqa/nutrients/pubs/circ1350.
    \41\ The serious illness in infants is caused because nitrate is 
converted to nitrite in the body. Nitrite interferes with the oxygen 
carrying capacity of the child's blood. This is an acute disease in 
that symptoms can develop rapidly in infants. In most cases, health 
deteriorates over a period of days. Symptoms include shortness of 
breath and blueness of the skin. (source: FDEP. 2010. Drinking 
Water: Inorganic Contaminants. Florida Department of Environmental 
Protection. http://www.dep.state.fl.us/water/drinkingwater/inorg_con.htm. Accessed September 2010.)
    \42\ EPA has also set a drinking water standard for nitrite at 1 
mg/L. To allow for the fact that the toxicity of nitrate and nitrite 
are additive, EPA has also established a standard for the sum of 
nitrate and nitrite at 10 mg/L. (source: FDEP. 2010. Drinking Water: 
Inorganic Contaminants. Florida Department of Environmental 
Protection. http://www.dep.state.fl.us/water/drinkingwater/inorg_con.htm. Accessed September 2010.)
    \43\ FDEP. 2010. Drinking Water: Inorganic Contaminants. Florida 
Department of Environmental Protection. http://www.dep.state.fl.us/water/drinkingwater/inorg_con.htm. Accessed September 2010.
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    Human health can also be impacted by disinfection byproducts formed 
when disinfectants (such as chlorine) used to treat drinking water 
react with organic carbon (from the algae in source waters). Some 
disinfection byproducts have been linked to rectal, bladder, and colon 
cancers; reproductive health risks; and liver, kidney, and central 
nervous system problems.44 45
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    \44\ USEPA. 2009. National Primary Drinking Water Regulations. 
Contaminants. U.S. Environmental Protection Agency. Accessed http://www.epa.gov/safewater/hfacts.html. December 2009.
    \45\ National Primary Drinking Water Regulations: Stage 2 
Disinfectants and Disinfection Byproducts Rule, 40 CFR parts 9, 141, 
and 142. U.S. Environmental Protection Agency, FR 71:2 (January 4, 
2006). pp. 387-493. Available electronically at: http://www.epa.gov/fedrgstr/EPA-WATER/2006/January/Day-04/w03.htm. Accessed December 
2009.
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    Economic losses from algal blooms and harmful algal blooms can 
include increased costs for drinking water treatment, reduced property 
values for streams and lakefront areas, commercial fishery losses, and 
lost revenue from recreational fishing, boating trips, and other 
tourism-related businesses.
    In terms of increased costs for drinking water treatment, for 
example, in 1991, Des Moines (Iowa) Water Works constructed a $4 
million ion exchange facility to remove nitrate from its drinking water 
supply. This facility was designed to be used an average of 35-40 days 
per year to remove excess nitrate levels at a cost of nearly $3000 per 
day.\46\
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    \46\ Jones, C.S., D. Hill, and G. Brand. 2007. Use a 
multifaceted approach to manage high sourcewater nitrate. Opflow 
June pp. 20-22.
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    Fremont, Ohio (a city of approximately 20,000) has experienced high 
levels of nitrate from its source, the Sandusky River, resulting in 
numerous drinking water use advisories. An estimated $15 million will 
be needed to build a reservoir (and associated piping) that will allow 
for selective withdrawal from the river to avoid elevated levels of 
nitrate, as well as to provide storage.\47\
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    \47\ Taft, Jim, Association of State Drinking Water 
Administrators (ASDWA). 2009. Personal Communication.
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    In regulating allowable levels of chlorophyll a in Oklahoma 
drinking water reservoirs, the Oklahoma Water Resources Board estimated 
that the long-term cost savings in drinking water treatment for 86 
systems would range between $106 million and $615 million if such 
regulations were implemented.\48\
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    \48\ Moershel, Philip, Oklahoma Water Resources Board (OWRB) and 
Mark Derischweiler, Oklahoma Department of Environmental Quality 
(ODEQ). 2009. Personal Communication.
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3. Nitrogen/Phosphorus Pollution in Florida
    Florida's flat topography causes water to move slowly over the 
landscape, allowing ample opportunity for nitrogen and phosphorus to 
dissolve and eutrophication responses to develop. Florida's warm and 
wet, yet sunny, climate further contributes to increased run-off and 
ideal temperatures for subsequent eutrophication responses.\49\
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    \49\ Perry, W. B. 2008. Everglades restoration and water quality 
challenges in south Florida. Ecotoxicology 17:569-578.
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    As outlined in the EPA January 2009 determination and the January 
2010 proposal, water quality degradation resulting from excess nitrogen 
and phosphorus loadings is a documented and significant environmental 
issue in Florida. FDEP notes in its 2008 Integrated Water Quality 
Assessment that nutrient pollution poses several challenges in Florida. 
For example, the FDEP 2008 Integrated Water Quality Assessment notes: 
``the close connection between surface and ground water, in combination 
with the pressures of continued population growth, accompanying 
development, and extensive agricultural operations, present Florida 
with a unique set of challenges for managing both water quality and 
quantity in the future. After trending downward for 20 years, beginning 
in 2000 phosphorus levels again began moving upward, likely due to the 
cumulative impacts of nonpoint source pollution associated with 
increased population and development. Increasing pollution from urban 
stormwater and agricultural activities is having other significant 
effects. In many springs across the State, for example, nitrate levels 
have increased dramatically (twofold to threefold) over the past 20 
years, reflecting the close link between surface and ground water.'' 
\50\ To clarify current nitrogen/phosphorus pollution conditions in 
Florida, EPA analyzed recent STORET data pulled from Florida's Impaired 
Waters Rule (IWR),\51\ (which are the data Florida uses to create its 
integrated reports) and found increasing levels of nitrogen and 
phosphorus compounds in Florida waters over the past 12 years (1996-
2008). Florida's IWR STORET data indicates that levels of total 
nitrogen have increased from a State-wide average of 1.06 mg/L in 1996 
to 1.27 mg/L in 2008 and total phosphorus levels have increased from an 
average of 0.108 mg/L in 1996 to 0.151 mg/L in 2008.
---------------------------------------------------------------------------

    \50\ FDEP. 2008. Integrated Water Quality Assessment for 
Florida: 2008 305(b) Report and 303(d) List Update.
    \51\ IWR Run 40. Updated through February 2010.
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    The combination of the factors reported by FDEP and listed above 
(including population increase, climate, stormwater runoff, 
agriculture, and topography) has contributed to significant nitrogen/
phosphorus effects to Florida's waters.\52\ For example, newspapers in 
Florida regularly report about impacts associated with nitrogen/
phosphorus pollution; recent examples include reports of algal blooms 
and fish kills in the St Johns River \53\ and reports of white foam 
associated with algal blooms lining parts of the St. Johns River.\54\ 
Spring releases of water from Lake Okeechobee into the St Lucie Canal, 
necessitated by high lake levels due to rainfall, resulted in reports 
of floating mats of toxic Microcystis aeruginosa that prompted Martin 
and St Lucie county health departments to issue warnings to the 
public.\55\
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    \52\ FDEP. 2008. Integrated Water Quality Assessment for 
Florida: 2008 305(b) Report and 303(d) List Update.
    \53\ Patterson, S. 2010, July 23. St John's River Looks Sick. 
Florida Times Union. http://jacksonville.com/news/metro/2010-07-23/story/st-johns-looks-sick-nelson-says. Accessed September 2010.
    \54\ Patterson, S. 2010, July 21. Foam on St. John's River 
Churns Up Environmental Interest. Florida Times Union. http://jacksonville.com/news/metro/2010-07-21/story/foam-st-johns-churns-environmental-questions. Accessed October 2010.
    \55\ Killer, E. 2010, June 10. Blue-green Algae Found Floating 
Near Palm City as Lake Okeechobee Releases Continue. Treasure Coast 
Times. http://www.tcpalm.com/news/2010/jun/10/blue-green-algae-found-floating-near-palm-city-o/. Accessed October 2010.
---------------------------------------------------------------------------

    The 2008 Integrated Water Quality Assessment lists nutrients as the 
fourth major source of impairment for rivers and streams in Florida 
(after dissolved oxygen, mercury in fish, and fecal coliforms). For 
lakes and estuaries, nutrients are ranked first and second, 
respectively. These same rankings are also confirmed in FDEP's latest 
2010 Integrated Water Quality Assessment.

[[Page 75769]]

    According to FDEP's 2008 Integrated Water Quality Assessment,\56\ 
approximately 1,049 miles of rivers and streams, 349,248 acres of 
lakes, and 902 square miles of estuaries are impaired by nutrients in 
the State. To put this in context and as noted above, approximately 5% 
of the total assessed river and stream miles, 23% of the total assessed 
lake acres, and 24% of the total assessed square miles of estuaries are 
impaired for nutrients according to the 2008 Integrated Report.\57\ In 
recent published listings of impairments for 2010, Florida Department 
of Environmental Protection lists nutrient impairments in 1,918 stream 
miles (about 8% of the total assessed stream miles), 378,435 lake acres 
(about 26% of total assessed lake acres), and 569 square miles of 
estuaries (about 21% of total assessed estuarine square miles).\58\
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    \56\ FDEP. 2008. Integrated Water Quality Assessment for 
Florida: 2008 305(b) Report and 303(d) List Update.
    \57\ FDEP. 2008. Integrated Water Quality Assessment for 
Florida: 2008 305(b) Report and 303(d) List Update.
    \58\ FDEP. 2010. Integrated Water Quality Assessment for 
Florida: 2010 305(b) Report and 303(d) List Update.
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    Compared to FDEP's 2008 Integrated Water Quality Assessment, the 
2010 Integrated Water Quality Assessment shows an increase in nutrient 
impairments for rivers and streams (from approximately 1000 miles to 
1918 miles) and lakes (from approximately 350,000 lake acres to 378,435 
lake acres). While the square miles of estuaries identified as impaired 
by nutrients decreased from 2008 to 2010 (from approximately 900 to 569 
square miles), the 2010 Integrated Water Quality Assessment notes that 
all square miles of estuaries in the report were decreased based on 
improved GIS techniques and corrected waterbody descriptions.\59\ 
Consequently, the decrease in estuarine square miles identified as 
impaired by nutrients in 2010 does not necessarily reflect a 
corresponding decrease in nitrogen/phosphorus pollution affecting 
Florida's estuarine water bodies.
---------------------------------------------------------------------------

    \59\ FDEP. 2010. Integrated Water Quality Assessment for 
Florida: 2010 305(b) Report and 303(d) List Update.
---------------------------------------------------------------------------

    FDEP has expressed concern about nitrogen/phosphorus pollution in 
Florida surface waters,\60\ in addition to concerns about freshwater 
harmful algal blooms and the potential for adverse human health impacts 
as noted in FDEP's 2008 Integrated Water Quality Assessment.\61\ This 
concern is underscored by a toxic blue-green algae bloom that occurred 
north of the Franklin Lock on the Caloosahatchee River in mid-June 
2008. The Olga Water Treatment Plant, which obtains its source water 
from the Caloosahatchee and provides drinking water for 30,000 people, 
was forced to temporarily shut down as a result of this bloom.\62\
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    \60\ ``While significant progress has been made in reducing 
nutrient loads from point sources and from new development, nutrient 
loading and the resulting harmful algal blooms continue to be an 
issue. The occurrence of blue-green algae is natural and has 
occurred throughout history; however, algal blooms caused by 
nutrient loading from fertilizer use, together with a growing 
population and the resulting increase in residential landscapes, are 
an ongoing concern.'' FDEP. 2010. Integrated Water Quality 
Assessment for Florida: 2010 305(b) Report and 303(d) List Update.
    \61\ ``Freshwater harmful algal blooms (HABs) are increasing in 
frequency, duration, and magnitude and therefore may be a 
significant threat to surface drinking water resources and 
recreational areas. Abundant populations of blue-green algae, some 
of them potentially toxigenic, have been found statewide in numerous 
lakes and rivers. In addition, measured concentrations of 
cyanotoxins--a few of them of above the suggested guideline levels--
have been reported in finished water from some drinking water 
facilities.'' FDEP. 2008. Integrated Water Quality Assessment for 
Florida: 2008 305(b) Report and 303(d) List Update.
    \62\ Peltier, M. 2008. Group files suit to enforce EPA water 
standards. Naples News. http://news.caloosahatchee.org/docs/NaplesNews_080717.htm. Accessed August 2010.
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    There has also been an increase in the level of pollutants, 
especially nitrate, in groundwater over the past decades.\63\ The 
Florida Geological Survey concluded that ``The presence of nitrate and 
the other nitrogenous compounds in ground water, is not considered in 
Florida to be a result of interaction of aquifer system water with 
surrounding rock materials. Nitrate in ground water is a result of 
specific land uses.'' \64\
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    \63\ Scott, T.M., G.H. Means, R.P. Meegan, R.C. Means, S.B. 
Upchurch, R.E. Copeland, J. Jones, T. Roberts, and A. Willet. 2004. 
Springs of Florida. Bulletin No. 66. Florida Geological Survey, 
Tallahassee, FL. 677 pp.
    \64\ FL Geological Survey. 1992. Special Publication No. 34, 
Florida's Ground Water Quality Monitoring Program, (nitrate-pp 36-
6).
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    Historically, nitrate+nitrite concentrations in Florida's spring 
discharges were estimated to have been around 0.05 mg/L or less, which 
is sufficiently low to restrict growth of algae and vegetation under 
``natural'' conditions.\65\ Of 125 spring vents sampled by the Florida 
Geological Survey in 2001-2002, 42% had nitrate+nitrite concentrations 
exceeding 0.50 mg/L and 24% had concentrations greater than 1.0 mg/
L.\66\ In the same study, mean nitrate+nitrite levels in 13 first-order 
springs were observed to have increased from 0.05 mg/L to 0.9 mg/L 
between 1970 and 2002. Overall, data suggest that nitrate+nitrite 
concentrations in many spring discharges have increased by an order of 
magnitude or a factor of 10 over the past 50 years, with the level of 
increase closely correlated with anthropogenic activity and land use 
changes within the karst regions of Florida where springs most often 
occur.\67\
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    \65\ Maddox, G.L., J.M. Lloyd, T.M. Scott, S.B. Upchurch and R. 
Copeland. 1992. Florida's Groundwater Quality Monitoring Program--
Background Hydrochemistry. Florida Geological Survey Special 
Publication No. 34, Tallahassee, FL.
    \66\ Scott, T.M., G.H. Means, R.P. Meegan, R.C. Means, S.B. 
Upchurch, R.E. Copeland, J. Jones, T. Roberts, and A. Willet. 2004. 
Springs of Florida. Bulletin No. 66. Florida Geological Survey, 
Tallahassee, FL. 677 pp.
    \67\ Katz, B.G., H.D. Hornsby, J.F. Bohlke and M.F. Mokray. 
1999. Sources and chronology of nitrate contamination in spring 
water, Suwannee River Basin, Florida. Water-Resources Investigations 
Report 99-4252. U.S. Geological Survey, Tallahassee, FL. Available 
electronically at: http://fl.water.usgs.gov/PDF_files/wri99_4252_katz.pdf.
    Scott, T.M., G.H. Means, R.P. Meegan, R.C. Means, S.B. Upchurch, 
R.E. Copeland, J. Jones, T. Roberts, and A. Willet. 2004. Springs of 
Florida. Bulletin No. 66. Florida Geological Survey, Tallahassee, 
FL. 677 pp.
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    Nitrates are found in ground water and wells in Florida, ranging 
from the detection limit of 0.02 mg/L to over 20 mg/L. Monitoring of 
Florida Public Water Supplies from 2004-2009 indicates that exceedances 
of nitrate maximum contaminant levels (MCL) (which are measured at the 
entry point of the distribution system and represent treated drinking 
water from a supplier) reported by drinking water plants in Florida 
ranged from 34-40 annually, during this period.\68\
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    \68\ FDEP. 2009. Chemical Data for 2004, 2005, 2006, 2007 2008, 
and 2009. Florida Department of Environmental Protection. http://www.dep.state.fl.us/water/drinkingwater/chemdata.htm. Accessed 
January 2010.
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    About 10% of Florida residents receive their drinking water from a 
private well or small public source not inventoried under public 
supply.\69\ A study in the late 1980s conducted by Florida Department 
of Agriculture and Consumer Services (FDACS) and FDEP, analyzed 3,949 
shallow drinking water wells for nitrate.70 71 Nitrate was 
detected in 2,483 (63%) wells, with 584 wells (15%) above the MCL of 10 
mg/L. Of the 584 wells that exceeded the MCL, 519 were located in Lake, 
Polk,

[[Page 75770]]

and Highland counties located in Central Florida. Results of monitoring 
conducted between 1999 and 2003 in a network of wells in that area 
indicated that of the 31 monitoring wells, 90% exceeded the nitrate 
drinking-water standard of 10 mg/L one or more times.72 73 
FDEP monitored this same area (the VISA monitoring network) in 1990, 
1993, and 1996, analyzing samples from 15-17 wells each cycle and 
reported median concentrations ranging from 17 to 20 mg/L nitrate, 
depending on the year.\74\ Some areas of Florida tend to be more 
susceptible to groundwater impacts from nitrogen pollution, especially 
those that have sandy soils, have high hydraulic conductivity, and have 
overlying land uses that are subject to applications of fertilizers and 
animal or human wastes.\75\ For example, USGS reports that in Highland 
county, highly developed suburban and agricultural areas tend to have 
levels of nitrates in the surficial groundwater that approach and can 
exceed the State primary drinking water standard of 10 mg/L for public 
water systems. Other areas in Highland county that are less developed 
tend to have much lower levels of nitrates in the surficial 
groundwater, often below detection levels.
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    \69\ Marella, R.L. 2009. Water Withdrawals, Use, and Trends in 
Florida, 2005. Scientific Investigations Report 2009-5125. U.S. 
Geological Survey, Reston, VA.
    \70\ Southern Regional Water Program. 2010. Drinking Water and 
Human Health in Florida. http://srwqis.tamu.edu/florida/program-information/florida-target-themes/drinking-water-and-human-health.aspx. Accessed January 2010.
    \71\ T.A. Obreza and K.T. Morgan. 2008. Nutrition of Florida 
Citrus Trees 15 months after publication of the final rule, except 
for the Federal site-specific alternative criteria (SSAC) procedure 
in section 131.43(e) of the rule which will go into effect 60 days 
after publication. 2nd ed. SL 253. University of Florida, IFAS 
Extension. http://edis.ifas.ufl.edu/pdffiles/SS/SS47800.pdf. 
Accessed September 2010.
    \72\ T.A. Obreza and K.T. Morgan. 2008. Nutrition of Florida 
Citrus Trees. 2nd ed. SL 253. University of Florida, IFAS Extension. 
http://edis.ifas.ufl.edu/pdffiles/SS/SS47800.pdf. Accessed September 
2010.
    \73\ USGS. 2009, November. Overview of Agricultural Chemicals: 
Pesticides and Nitrate. http://fl.water.usgs.gov/Lake_Wales_Ridge/html/overview_of_agrichemicals.html. Accessed September 2010.
    \74\ FDEP. 1998. Ground Water Quality and Agricultural Land Use 
in the Polk County Very Intense Study Area (VISA). Florida 
Department of Environmental Protection, Division of Water 
Facilities. http://www.dep.state.fl.us/water/monitoring/docs/facts/fs9802.pdf. Accessed September 2010.
    \75\ USGS. 2010. Hydrogeology and Groundwater Quality of 
Highlands County, FL. Scientific Investigations Report 2010-5097. 
U.S. Geological Survey, Reston, VA.
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    The Floridian aquifer system is one of the largest sources of 
ground water in the U.S., and serves as a primary source of drinking 
water in Northern Florida. The Upper Floridian aquifer is unconfined or 
semiconfined in areas in Northern Florida, but is also confined by the 
overlying surficial aquifer system which is used for water supply. 
Wells in unconfined areas of the Upper Floridian aquifer tested in 
northern Florida had nitrate levels higher than 1 mg/L in 40% of wells; 
17% of samples from the semiconfined area had nitrate levels above 1 
mg/L. In both aquifer systems this indicates the widespread impact of 
nitrate on groundwater quality in this area.76 77 This 
baseline sampling indicates a pattern of widespread nitrate occurrence 
in the Upper Floridian aquifer from two decades ago. A portion of these 
early samples exceeded 10 mg/L nitrate (25 of the 726 samples taken 
from this unconfined or semi-confined aquifer; 50 of the 421 water 
samples from the surficial aquifer).
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    \76\ Berndt, M.P., 1996. Ground-water quality assessment of the 
Georgia-Florida Coastal Plain study unit--Analysis of available 
information on nutrients, 1972-92. Water-Resources Investigations 
Report 95-4039. U.S. Geological Survey, Tallahassee, FL.
    \77\ Berndt, Marian P., 1993. National Water-Quality Assessment 
Program-Preliminary assessment of nitrate distribution in ground 
water in the Georgia-Florida Coastal Plain Study Unit, 1972-90. 
Open-File Report 93-478. U.S. Geological Survey.
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    Growing population trends in Florida contribute to the significant 
challenge of addressing nitrogen/phosphorus pollution in Florida. 
Historically, the State has experienced a rapidly expanding population. 
Significantly growing demographics are considered to be a strong 
predictor of nitrogen/phosphorus loading and associated effects because 
of increases in stormwater runoff from increased impervious surfaces 
and increased wastewater treatment flows both of which typically 
contain some level of nitrogen/phosphorus.\78\ Florida is currently the 
fourth most populous State in the nation, with an estimated 18 million 
people.\79\ The U.S. Census bureau predicts the Florida population will 
exceed 28 million people by 2030, making Florida the third most 
populous State in the U.S.\80\
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    \78\ National Research Council, Committee on Reducing Stormwater 
Discharge Contributions to Water Pollution. 2008. Urban Stormwater 
Management in the United States. National Academies Press, 
Washington, DC.
    \79\ U.S. Census Bureau. 2009. 2008 Population Estimates Ranked 
by State. http://factfinder.census.gov. Accessed January 2010.
    \80\ U.S. Census Bureau. 2009. 2008 Population Estimates Ranked 
by State. http://factfinder.census.gov. Accessed January 2010.
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B. Statutory and Regulatory Background

    Section 303(c) of the CWA (33 U.S.C. 1313(c)) directs States to 
adopt WQS for their navigable waters. Section 303(c)(2)(A) and EPA's 
implementing regulations at 40 CFR part 131 require, among other 
things, that State WQS include the designated use or uses to be made of 
the waters and criteria that protect those uses. EPA regulations at 40 
CFR 131.11(a)(1) provide that States shall ``adopt those water quality 
criteria that protect the designated use'' and that such criteria 
``must be based on sound scientific rationale and must contain 
sufficient parameters or constituents to protect the designated use.'' 
As noted above, 40 CFR 130.10(b) provides that ``[i]n designating uses 
of a waterbody 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 also required to review their WQS at least once every 
three years and, if appropriate, revise or adopt new standards. (See 
CWA section 303(c)(1)). Any new or revised WQS must be submitted to EPA 
for review and approval or disapproval. (See CWA section 303(c)(2)(A)). 
Finally, 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 needed to meet CWA requirements. The criteria 
finalized in this rulemaking translate Florida's narrative nutrient 
provision at Subsection 62-302-530(47)(b), F.A.C., into numeric values 
that apply to lakes and springs throughout Florida and flowing waters 
outside of the South Florida Region.\81\
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    \81\ The criteria finalized in this rulemaking do not address or 
translate Florida's narrative nutrient provision at Subsection 62-
302.530(47)(a), F.A.C. Subsection 62-302.530(47)(a), F.A.C., remains 
in place as an applicable WQS for CWA purposes.
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C. Water Quality Criteria

    Under CWA section 304(a), EPA periodically publishes criteria 
recommendations (guidance) for use by States in setting water quality 
criteria for particular parameters to protect recreational and aquatic 
life uses of waters. Where EPA has published recommended criteria, 
States have the option of adopting water quality criteria based on 
EPA's CWA section 304(a) criteria guidance, section 304(a) criteria 
guidance modified to reflect site-specific conditions, or other 
scientifically defensible methods. (See 40 CFR 131.11(b)(1)). For 
nitrogen/phosphorus pollution, EPA has published under CWA section 
304(a) a series of peer-reviewed, national technical approaches and 
methods regarding the development of numeric criteria for lakes and 
reservoirs,\82\ rivers and streams,\83\ and estuaries and coastal 
marine waters.\84\
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    \82\ USEPA. 2000a. Nutrient Criteria Technical Guidance Manual: 
Lakes and Reservoirs. EPA-822-B-00-001. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC.
    \83\ USEPA. 2000b. Nutrient Criteria Technical Guidance Manual: 
Rivers and Streams. EPA-822-B-00-002. U.S. Environmental Protection 
Agency, Office of Water, Washington, DC.
    \84\ USEPA. 2001. Nutrient Criteria Technical Manual: Estuarine 
and Coastal Marine Waters. EPA-822-B-01-003. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC.

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[[Page 75771]]

    EPA based the methodologies used to develop numeric criteria for 
Florida in this regulation on its published guidance on developing 
criteria that identifies three general approaches for criteria setting. 
The three types of empirical analyses provide distinctly different, 
independently and scientifically defensible, approaches for deriving 
nutrient criteria from field data: (1) Reference condition approach 
derives candidate criteria from observations collected in reference 
waterbodies, (2) mechanistic modeling approach represents ecological 
systems using equations that represent ecological processes and 
parameters for these equations that can be calibrated empirically from 
site-specific data, and (3) empirical nutrient stressor-response 
modeling is used when data are available to accurately estimate a 
relationship between nutrient concentrations and a response measure 
that is directly or indirectly related to a designated use of the 
waterbody (e.g., a biological index or recreational use measure). Then, 
nutrient concentrations that are protective of designated uses can be 
derived from the estimated relationship).\85\ Each of these three 
analytical approaches is appropriate for deriving scientifically 
defensible numeric nutrient criteria when applied with consideration of 
method-specific data needs and available data. In addition to these 
empirical approaches, consideration of established (e.g., published) 
nutrient response thresholds is also an acceptable approach for 
deriving criteria.\86\
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    \85\ USEPA. 2000a. Nutrient Criteria Technical Guidance Manual: 
Lakes and Reservoirs. EPA-822-B-00-001. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC.
    USEPA. 2000b. Nutrient Criteria Technical Guidance Manual: 
Rivers and Streams. EPA-822-B-00-002. U.S. Environmental Protection 
Agency, Office of Water, Washington, DC.
    USEPA. 2001. Nutrient Criteria Technical Guidance Manual: 
Estuarine and Coastal Marine Waters. EPA-822-B-01-003. U.S. 
Environmental Protection Agency, Office of Water, Washington, DC.
    USEPA. 2008. Nutrient Criteria Technical Guidance Manual: 
Wetlands. EPA-822-B-08-001. U.S. Environmental Protection Agency, 
Office of Water, Washington, DC.
    \86\ USEPA. 2000a. Nutrient Criteria Technical Guidance Manual: 
Lakes and Reservoirs. EPA-822-B-00-001. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC.
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    For lakes, EPA used a stressor-response approach to link nitrogen/
phosphorus concentrations to predictions of corresponding chlorophyll a 
concentrations. EPA used a reference-based approach for streams, 
relying on a comprehensive screening methodology to identify least-
disturbed streams as reference streams. For springs, EPA used algal or 
nitrogen/phosphorus thresholds developed under laboratory conditions 
and stressor-response relationships from several field studies of algal 
growth in springs. For each type of waterbody, EPA carefully considered 
the available data and evaluated several lines of evidence to derive 
scientifically sound approaches (as noted above) for developing the 
final numeric criteria.
    Based on comments received from the Scientific Advisory Board 
(SAB), EPA has modified a draft methodology guidance document on using 
stressor-response relationships for deriving numeric criteria, which is 
available as a final technical guidance document.\87\ In addition, the 
reference-based and algal or nitrogen/phosphorus threshold approaches 
have been peer reviewed and have been available for many years.
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    \87\ USEPA. 2010. Using Stressor-Response Relationships to 
Derive Numeric Nutrient Criteria. EPA-820-S-10-001. U.S. 
Environmental Protection Agency, Office of Water, Washington, DC.
---------------------------------------------------------------------------

    As mentioned above, the criteria finalized in this rulemaking 
translate Florida's narrative nutrient provision at Subsection 62-
302.530(47)(b), F.A.C., (``[i]n no case shall nutrient concentrations 
of a body of water be altered so as to cause an imbalance in natural 
populations of aquatic flora or fauna'') into numeric values that apply 
to lakes and springs throughout the State and flowing waters outside of 
the South Florida Region. EPA believes that numeric criteria will 
expedite and facilitate the effective implementation of Florida's 
existing point and non-point source water quality programs in terms of 
timely water quality assessments, TMDL development, NPDES permit 
issuance and, where needed, Basin Management Action Plans (BMAPs) to 
address nitrogen/phosphorus pollution. EPA notes that Subsection 62-
302.530(47)(a), F.A.C. (``[t]he discharge of nutrients shall continue 
to be limited as needed to prevent violations of other standards 
contained in this chapter. Man-induced nutrient enrichment (total 
nitrogen or total phosphorus) shall be considered degradation in 
relation to the provisions of Sections 62-302.300, 62-302.700, and 62-
4.242, F.A.C.'') could result in more stringent nitrogen/phosphorus 
limits, where necessary to protect other applicable WQS in Florida.

D. EPA Determination Regarding Florida and EPA's Rulemaking

    On January 14, 2009, EPA determined under CWA section 303(c)(4)(B) 
that new or revised WQS in the form of numeric water quality criteria 
for nitrogen/phosphorus pollution are necessary to meet the 
requirements of the CWA in the State of Florida. As noted above, the 
portion of Florida's currently applicable narrative criterion 
translated by this final rule provides, in part, that ``in no case 
shall nutrient concentrations of a body of water be altered so as to 
cause an imbalance in natural populations of aquatic flora or fauna.'' 
(See Subsection 62-302.530(47)(b), F.A.C.). EPA determined that 
Florida's narrative criterion alone was insufficient to ensure 
protection of applicable designated uses. The determination recognized 
that Florida has a comprehensive regulatory and non-regulatory 
administrative water quality program to address nitrogen/phosphorus 
pollution through a water quality strategy of assessments, non-
attainment listing and determinations, TMDL development, and National 
Pollutant Discharge Elimination System (NPDES) permit regulations; 
individual watershed management plans through the State's BMAPs; 
advanced wastewater treatment technology-based requirements under the 
1990 Grizzle-Figg Act; together with rules to limit nitrogen/phosphorus 
pollution in geographically specific areas like the Indian River Lagoon 
System, the Everglades Protection Area, and Wekiva Springs. However, 
the determination noted that despite Florida's existing regulatory and 
non-regulatory water quality framework and the State's intensive 
efforts to diagnose nitrogen/phosphorus pollution and address it on a 
time-consuming and resource-intensive case-by-case basis, substantial 
water quality degradation from nitrogen/phosphorus over-enrichment 
remains a significant challenge in the State and conditions are likely 
to worsen with continued population growth and land-use changes.
    Overall, the combined impacts of urban and agricultural activities, 
along with Florida's physical features and important and unique aquatic 
ecosystems, made it clear that the current reliance on the narrative 
criterion alone and a resource-intensive, site-specific implementation 
approach, and the resulting delays that it entails, do not ensure 
protection of applicable designated uses for the many State waters that 
either have been listed as impaired and require loadings reductions or 
those that are high quality and require protection from future 
degradation. EPA concluded that numeric criteria for nitrogen/
phosphorus pollution will enable the State to take necessary action to 
protect

[[Page 75772]]

the designated uses in a timely manner that will ensure protection of 
the designated use. The resource-intensive efforts to interpret the 
State's narrative criterion contribute to substantial delays in 
implementing the criterion and, therefore, undercut the State's ability 
to provide the needed protections for applicable designated uses. EPA, 
therefore, determined that numeric criteria for nitrogen/phosphorus 
pollution are necessary for the State of Florida to meet the CWA 
requirement to have criteria that protect applicable designated uses. 
EPA determined that numeric water quality criteria would strengthen the 
foundation for identifying impaired waters, establishing TMDLs, and 
deriving water quality-based effluent limits in NPDES permits, thus 
providing the necessary protection for the State's designated uses in 
its waters. In addition, numeric criteria will support the State's 
ability to effectively partner with point and nonpoint sources to 
control nitrogen/phosphorus pollution, thus further providing the 
necessary protection for the designated uses of the State's water 
bodies. EPA's determination is available at the following Web site: 
http://www.epa.gov/waterscience/standards/rules/fl-determination.htm.
    While Florida continues to work to implement its watershed 
management program, the impairments for nutrient pollution are 
increasing as evidenced by the 2008 and 2010 Integrated Water Quality 
Assessment for Florida report results, and the tools to correct the 
impairments (TMDLs and BMAPs) are not being completed at a pace to keep 
up. Numeric criteria can be used as a definitive monitoring tool to 
identify impaired waters and as an endpoint for TMDLs to establish 
allowable loads necessary to correct impairments. When developing 
TMDLs, as it does when determining reasonable potential and deriving 
limits in the permitting context, Florida translates the narrative 
criterion into a numeric target that the State determines is necessary 
to meet its narrative criterion and protect applicable designated uses. 
This process involves a site-specific analysis to determine the 
nitrogen and phosphorus concentrations that would ``cause an imbalance 
in natural populations of aquatic flora or fauna'' in a particular 
water.
    When deriving NPDES water quality-based permit limits, Florida 
initially conducts a site-specific analysis to determine whether a 
proposed discharge has the reasonable potential to cause or contribute 
to an exceedance of its narrative water quality criterion. The absence 
of numeric criteria make this ``reasonable potential'' analysis more 
complex, data-intensive, and protracted. Following a reasonable 
potential analysis, the State then evaluates what levels of nitrogen 
and phosphorus would ``cause an imbalance in natural populations of 
aquatic flora or fauna'' and translates those levels into numeric 
``targets'' for the receiving water and any other affected waters. 
Determining on a State-wide, water-by-water basis the levels of 
nitrogen and phosphorus that would ``cause an imbalance in natural 
populations of aquatic flora or fauna'' is a difficult, lengthy, and 
data-intensive undertaking. This work involves performing detailed 
location-specific analyses of the receiving water. If the State has not 
already completed this analysis for a particular waterbody, it can be 
very difficult to accurately determine in the context and timeframe of 
the NPDES permitting process. For example, in some cases, site-specific 
data may take several years to collect and, therefore, may not be 
available for a particular waterbody at the time of permitting issuance 
or re-issuance.
    The January 14, 2009 determination stated EPA's intent to propose 
numeric criteria for lakes and flowing waters in Florida within 12 
months of the January 14, 2009 determination, and for estuarine and 
coastal waters within 24 months of the determination. On August 19, 
2009, EPA entered into a Consent Decree with Florida Wildlife 
Federation, Sierra Club, Conservancy of Southwest Florida, 
Environmental Confederation of Southwest Florida, and St. Johns 
Riverkeeper, committing to the schedule stated in EPA's January 14, 
2009 determination to propose numeric criteria for lakes and flowing 
waters in Florida by January 14, 2010, and for Florida's estuarine and 
coastal waters by January 14, 2011. The Consent Decree also required 
that final rules be issued by October 15, 2010 for lakes and flowing 
waters, and by October 15, 2011 for estuarine and coastal waters. FDEP, 
independently from EPA, initiated its own State rulemaking process in 
the spring/summer of 2009 to adopt nutrient water quality standards 
protective of Florida's lakes and flowing waters. FDEP held several 
public workshops on its draft numeric criteria for lakes and flowing 
waters. In October 2009, however, FDEP decided not to bring the draft 
criteria before the Florida Environmental Regulation Commission, as had 
been previously scheduled.
    Pursuant to the Consent Decree, EPA's Administrator signed the 
proposed numeric criteria for Florida's lakes and flowing waters on 
January 14, 2010, which was published in the Federal Register on 
January 26, 2010. EPA conducted a 90-day public comment period for this 
rule that closed on April 28, 2010. During this period, EPA also 
conducted 13 public hearing sessions in 6 cities in Florida. EPA 
received over 22,000 public comments from a variety of sources, 
including environmental groups, municipal wastewater associations, 
industry, State agencies, local governments, agricultural groups, and 
private citizens. The comments addressed a wide range of issues, 
including technical analyses, policy issues, economic costs, and 
implementation concerns. In this notice, EPA explains the inland waters 
final rule and provides a summary of major comments and the Agency's 
response in the sections that describe each of the provisions of the 
final rule. EPA has prepared a detailed ``Comment Response Document,'' 
which includes responses to the comments contributed during the public 
hearing sessions, as well as those submitted in writing on the proposed 
rule, and is located in the docket for this rule.
    On June 7, 2010, EPA and Plaintiffs filed a joint notice with the 
Court extending the deadlines for promulgating numeric criteria for 
Florida's estuaries and coastal waters, flowing waters in south Florida 
(including canals), and the downstream protection values for flowing 
waters into estuaries and coastal waters. The new deadlines are 
November 14, 2011 for proposing this second phase of criteria, and 
August 15, 2012 for publishing a final rule for these three categories. 
This will allow EPA time to hold a public peer review by EPA's 
Scientific Advisory Board (SAB) of the scientific methodologies for 
estuarine and coastal criteria, flowing waters in south Florida, and 
downstream protection values for estuaries and coastal waters.
    Based upon comments and new data and information received during 
the public comment phase of the January 2010 proposed rule, on August 
3, 2010 EPA published a supplemental notice of data availability and 
request for comment related to the Agency's January 26, 2010 notice of 
proposed rulemaking. In its supplemental notice, EPA solicited comment 
on a revised regionalization approach for streams, additional 
information and analysis on least-disturbed sites as part of a modified 
benchmark distribution approach, and additional options for developing 
downstream protection values (DPVs) for lakes. EPA did not solicit 
additional comment on any other provisions of the January 2010 
proposal. EPA received 71 public comments from a variety of sources, 
including local and State governments, industry, and

[[Page 75773]]

environmental groups. As mentioned above, EPA provides a summary of 
major comments and the Agency's response in the sections that describe 
each of the provisions of the final rule. Responses to comments 
submitted during the public comment period associated with the 
supplemental notice are also included in EPA's detailed ``Comment 
Response Document,'' located in the docket for this rule.
    On October 8, 2010, EPA filed an unopposed motion with the Court 
requesting that the deadline for signing the final rule be extended to 
November 14, 2010. The Court granted EPA's motion on October 27, 2010. 
EPA used this additional time to review and confirm that all comments 
were fully considered.
    In accordance with the January 14, 2009 determination, the August 
19, 2009 Consent Decree, and the June 7, 2010 and October 27, 2010 
revisions to that Consent Decree, in this final notice EPA is 
promulgating final numeric criteria for streams, lakes, and springs in 
the State of Florida.\88\
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    \88\ For purposes of this rule, EPA has distinguished South 
Florida as those areas south of Lake Okeechobee and the 
Caloosahatchee River watershed to the west of Lake Okeechobee and 
the St. Lucie watershed to the east of Lake Okeechobee, hereinafter 
referred to as the South Florida Region. Numeric criteria applicable 
to flowing waters in the South Florida Region will be addressed in 
the second phase of EPA's rulemaking regarding the establishment of 
estuarine and coastal numeric criteria. (Please refer to Section I.B 
for a discussion of the water bodies affected by this rule).
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III. Numeric Criteria for Streams, Lakes, and Springs in the State of 
Florida

A. General Information

    For this final rule, EPA derived numeric criteria for streams, 
lakes and springs to implement Florida Subsection 62-302.530(47)(b), 
F.A.C.\89\ This final rule also includes downstream protection values 
(DPVs) to ensure the attainment and maintenance of the WQS for 
downstream lakes. Derivation of these criteria is based upon an 
extensive amount of Florida-specific data. EPA has carefully considered 
numerous comments from a range of stakeholders and has worked in close 
collaboration with FDEP technical and scientific experts to analyze, 
evaluate, and interpret these Florida-specific data in deriving 
scientifically sound numeric criteria for this final rulemaking.
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    \89\ In no case shall nutrient concentrations of a body of water 
be altered so as to cause an imbalance in natural populations of 
aquatic flora or fauna.
---------------------------------------------------------------------------

    To support derivation of the final streams criteria, EPA screened 
and evaluated water chemistry data from more than 11,000 samples from 
over 6,000 sites statewide. EPA also evaluated biological data 
consisting of more than 2,000 samples from over 1,100 streams. To 
support derivation of the final lakes criteria, EPA screened and 
evaluated relevant lake data, which consisted of over 17,000 samples 
from more than 1,500 lakes statewide. Finally, for the final springs 
criterion, EPA evaluated and relied on scientific information and 
analyses from more than 40 studies including historical accounts, 
laboratory scale dosing studies and field surveys.
    In deriving these final numeric values, the EPA met and consulted 
with FDEP expert scientific and technical staff on numerous occasions 
as part of an ongoing collaborative process. EPA carefully considered 
and evaluated the technical approaches and scientific analysis that 
FDEP presented as part of its July 2009 draft numeric criteria,\90\ as 
well as its numerous comments on different aspects of this rule. The 
Agency also received and carefully considered substantial stakeholder 
input from 13 public hearings in 6 Florida cities. Finally, EPA 
reviewed and evaluated further analysis and information included in 
more than 22,000 comments on the January 2010 proposal and an 
additional 71 comments on the August 2010 supplemental notice.
---------------------------------------------------------------------------

    \90\ FDEP. 2009. Draft Technical Support Document: Development 
of Numeric Nutrient Criteria for Florida's Lakes and Streams. 
Florida Department of Environmental Protection, Standards and 
Assessment Section. Available electronically at: http://www.dep.state.fl.us/water/wqssp/nutrients/docs/tsd_nutrient_crit.docx. Accessed October 2010.
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    EPA has created a technical support document that provides detailed 
information regarding the methodologies discussed herein and the 
derivation of the final criteria. This document is entitled ``Technical 
Support Document for EPA's Final Rule for Numeric Criteria for 
Nitrogen/Phosphorus Pollution in Florida's Inland Surface Fresh 
Waters'' (``EPA Final Rule TSD for Florida's Inland Waters'' or 
``TSD'') and is part of the record and supporting documentation for 
this final rule. As part of its review of additional technical and 
scientific information, EPA has documented its consideration of key 
comments and issues received from a wide range of interested parties 
during the rulemaking process. This analysis and consideration is 
included as part of a comment response document entitled ``Response to 
Comments--EPA's Numeric Criteria for Nitrogen/Phosphorus Pollution in 
the State of Florida's Lakes and Flowing Waters'' that is also part of 
the record and supporting documentation for this final rule.
    This section of the preamble describes EPA's final numeric criteria 
for Florida's streams (III.B), lakes (III.C), and springs (III.D), with 
the associated methodologies EPA employed to derive them. Each 
subsection includes the final numeric criteria (magnitude, duration, 
and frequency) and background information and supporting analyses. 
Section III.E discusses the applicability and implementation of these 
final criteria.
    As discussed, the scientific basis for the derivation of the 
applicable criteria for streams, lakes and springs in this final rule 
is outlined below and explained in more detail in the Technical Support 
Document accompanying this rulemaking. The final criteria and related 
provisions in this rule reflect a detailed consideration and full 
utilization of the best available science, data, literature, and 
analysis related to the specific circumstances and contexts for 
deriving numeric criteria in the State of Florida. This includes, but 
is not limited to, the substantial quantity and quality of available 
data in Florida, Florida's regional hydrologic, biological, and land 
use characteristics, and the biological responses in Florida's surface 
water systems.

B. Numeric Criteria for the State of Florida's Streams

(1) Final Rule
    EPA is promulgating numeric criteria for TN and TP in five 
geographically distinct watershed regions of Florida's streams 
classified as Class I or III waters under Florida law (Section 62-
302.400, F.A.C.).

          Table B-1--EPA's Numeric Criteria for Florida Streams
------------------------------------------------------------------------
                                                     Instream protection
                                                       value criteria
             Nutrient watershed region             ---------------------
                                                     TN  (mg/   TP  (mg/
                                                       L) *       L) *
------------------------------------------------------------------------
Panhandle West \a\................................       0.67       0.06
Panhandle East \b\................................       1.03       0.18
North Central \c\.................................       1.87       0.30
West Central \d\..................................       1.65       0.49
Peninsula \e\.....................................       1.54       0.12
------------------------------------------------------------------------
Watersheds pertaining to each Nutrient Watershed Region (NWR) were based
  principally on the NOAA coastal, estuarine, and fluvial drainage areas
  with modifications to the NOAA drainage areas in the West Central and
  Peninsula Regions that account for unique watershed geologies. For
  more detailed information on regionalization and which WBIDs pertain
  to each NWR, see the Technical Support Document.

[[Page 75774]]

 
\a\ Panhandle West region includes: Perdido Bay Watershed, Pensacola Bay
  Watershed, Choctawhatchee Bay Watershed, St. Andrew Bay Watershed,
  Apalachicola Bay Watershed.
\b\ Panhandle East region includes: Apalachee Bay Watershed, and
  Econfina/Steinhatchee Coastal Drainage Area.
\c\ North Central region includes the Suwannee River Watershed.
\d\ West Central region includes: Peace, Myakka, Hillsborough, Alafia,
  Manatee, Little Manatee River Watersheds, and small, direct Tampa Bay
  tributary watersheds south of the Hillsborough River Watershed.
\e\ Peninsula region includes: Waccasassa Coastal Drainage Area,
  Withlacoochee Coastal Drainage Area, Crystal/Pithlachascotee Coastal
  Drainage Area, small, direct Tampa Bay tributary watersheds west of
  the Hillsborough River Watershed, Sarasota Bay Watershed, small,
  direct Charlotte Harbor tributary watersheds south of the Peace River
  Watershed, Caloosahatchee River Watershed, Estero Bay Watershed,
  Kissimmee River/Lake Okeechobee Drainage Area, Loxahatchee/St. Lucie
  Watershed, Indian River Watershed, Daytona/St. Augustine Coastal
  Drainage Area, St. John's River Watershed, Nassau Coastal Drainage
  Area, and St. Mary's River Watershed.
* For a given waterbody, the annual geometric mean of TN or TP
  concentrations shall not exceed the applicable criterion concentration
  more than once in a three-year period.

(2) Background and Analysis
(a) Methodology for Stream Classification
    In January 2010, EPA proposed to classify Florida's streams into 
four regions (referred to in the proposed rule as ``Nutrient Watershed 
Regions'') for application of TN and TP criteria. This proposal was 
based upon the premise that streams within each of these regions 
(Panhandle, Bone Valley, Peninsula and North Central) reflect similar 
geographical characteristics, including phosphorus-rich soils, 
nitrogen/phosphorus concentrations and nitrogen to phosphorus ratios. 
To classify these four regions, EPA began by considering the watershed 
boundaries of downstream estuaries and coastal waters in recognition of 
the hydrology of Florida's flowing waters and the importance of 
protecting downstream water quality. This is consistent with a 
watershed approach to water quality management, which EPA encourages to 
integrate and coordinate efforts within a watershed in order to most 
effectively and efficiently protect our nation's water resources.\91\ 
EPA then classified Florida's streams based upon a consideration of the 
natural factors that contribute to variability in nutrient 
concentrations in streams (e.g., geology, soil composition). In the 
State of Florida, these natural factors are mainly associated with 
phosphorus. EPA's proposal reflected a conclusion that these natural 
factors could best be represented by separating the watersheds in the 
State into four regions and then using the least-disturbed sites within 
those regions to differentiate between the expected natural 
concentrations of TN and TP.
---------------------------------------------------------------------------

    \91\ U.S. EPA. 2008. Handbook for Developing Watershed Plans to 
Restore and Protect Our Waters. EPA 841-B-08-002. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC.
---------------------------------------------------------------------------

    EPA received comments suggesting that the proposed stream 
regionalization be amended to more accurately account for naturally-
high phosphorus soils in the northern Panhandle, west of the proposed 
North Central region. Specifically, EPA was asked to consider the 
westward extent of the Hawthorn Group, a phosphorus-rich geological 
formation that can influence stream phosphorus concentrations. At 
proposal, EPA had taken the Hawthorn Group into account when it 
proposed two distinct stream regions to the east and south of the 
panhandle region: the North Central and the West Central (formerly 
called the Bone Valley at proposal). Following proposal and in response 
to these comments, EPA revisited its review of underlying soils and 
geology in the Panhandle, itself, and the relationship of those 
geological characteristics to observed patterns in phosphorus 
concentrations in streams. EPA further considered how well such a 
revised regionalization explained observed variability in TP 
concentrations relative to the proposed regionalization. EPA concluded 
that a revised regional classification subdividing the proposed 
Panhandle region into a western and eastern section accurately 
reflected phosphate contributions from the underlying geologic 
formations that are reflected in the expected instream phosphorus 
concentrations. As discussed in the August 2010 supplemental notice, 
EPA has used the revised Panhandle regions for TN criteria to assure 
consistency and clarity in applicability decisions and implementation. 
This approach addresses the concerns of commenters that regionalization 
is an important consideration in developing stream criteria. EPA 
provided a supplemental notice and solicitation of comment in August 
2010 on this potential change to the Panhandle region. In this final 
rule, EPA has thus taken into account the portion of the Hawthorn Group 
that lies in the eastern portion of the Panhandle region and has 
delineated the Panhandle region along watershed boundaries into East 
and West portions divided by the eastern edge of the Apalachicola River 
watershed (or alternatively, the western edge of the Suwannee River 
watershed). For more information regarding the EPA's consideration of 
alternative approaches for classification, please see the TSD and 
response to comments.
    EPA also received comment that the original West Central region 
(referred to as the Bone Valley in the proposed rule) was too broad and 
incorporated watersheds that were not influenced by underlying Hawthorn 
Group geology, especially small, direct coastal drainage watersheds 
along the western and southern boundaries. EPA reexamined the watershed 
delineations of the West Central and Peninsula regions based on 
information in these comments and concluded that the comments were 
technically correct. EPA also provided a supplemental notice and 
solicitation of comment on this potential change to the West Central 
and Peninsula regions. In this final rule, EPA has refined the boundary 
delineations accordingly. The result for the West Central region was a 
modified boundary that shifts small, direct Tampa Bay tributary 
watersheds west of the Hillsborough River Watershed; small, direct 
Charlotte Harbor tributary watersheds south of the Peace River 
Watershed; and the entire Sarasota Bay Watershed from the West Central 
(Bone Valley) to the Peninsula region. EPA believes these adjustments 
to the West Central and Peninsula stream region boundaries more 
accurately reflect the watershed boundaries and better reflect natural 
differences in underlying geological formations and expected stream 
chemistry.
    In summary, EPA is finalizing numeric stream criteria for TN and TP 
for five separate Nutrient Watershed Regions (NWR): Panhandle West, 
Panhandle East, North Central, West Central and Peninsula (north of 
Lake Okeechobee, including the Caloosahatchee River Watershed to the 
west and the St. Lucie Watershed to the east). For a map of these 
regions, refer to ``Technical Support Document for U.S. EPA's Final 
Rule for Numeric Criteria for Nitrogen/Phosphorus Pollution in 
Florida's Inland Surface Fresh Waters'' (Chapter 1: Derivation of EPA's 
Numeric Criteria for Streams) included in the docket as part of the 
record for this final rule.
(b) Methodology for Calculating Instream Protective TN and TP Values
    In the January 2010 proposal, EPA used a reference condition 
approach to derive numeric criteria that relied on the identification 
of biologically healthy sites that were unimpaired by nitrogen or 
phosphorus. EPA identified these sites from FDEP's streams data set, 
selecting sites where Stream Condition

[[Page 75775]]

Index (SCI) scores were 40 and higher. The SCI is a multi-metric index 
of benthic macroinvertebrate community composition and taxonomic data 
developed by FDEP to assess the biological health of Florida's 
streams.\92\ An SCI score > 40 has been determined to be indicative of 
biologically healthy conditions based on an expert workshop and 
analyses performed by both FDEP and EPA. Please refer to the EPA's 
January 2010 proposal and the final TSD accompanying this final rule 
for more information on the SCI and the selection of the SCI value of 
40 as an appropriate threshold to identify biologically healthy sites.
---------------------------------------------------------------------------

    \92\ The SCI method was developed and calibrated by FDEP. See 
Fore et al. 2007. Development and Testing of Biomonitoring Tools for 
Macroinvertebrates in Florida Streams (Stream Condition Index and 
BioRecon). Final prepared for the Florida Department of 
Environmental Protection, Tallahassee, FL.
---------------------------------------------------------------------------

    EPA further screened these sites by cross-referencing them with 
Florida's 2008 CWA section 303(d) list and excluded sites in waterbody 
identification numbers (WBIDs) with identified nutrient impairments or 
dissolved oxygen impairments. EPA grouped the remaining sites 
(hereinafter referred to as ``SCI sites'') according to the four 
proposed Nutrient Watershed Regions (Panhandle, North Central, West 
Central (referred to as Bone Valley at proposal), and Peninsula). For 
each NWR, EPA compiled data (TN and TP concentrations). EPA then 
calculated the average concentration at each site using all available 
samples. The resulting site average concentrations represent the 
distribution of nitrogen/phosphorus concentrations for each region. EPA 
found that while these sites were determined to be biologically 
healthy, the proposed SCI approach does not include information that 
can be directly related to an evaluation of least anthropogenically-
impacted conditions (e.g., a measure of land use surrounding a 
reference site), which can be used as a factor in identifying a 
minimally-impacted reference population for criteria development. For 
these reasons, EPA concluded the 75th percentile of the distribution of 
site average values was an appropriate threshold to use in the SCI 
approach for criteria derivation.
    EPA requested comment on basing the TN and TP criteria for the 
Nutrient Watershed Regions on the SCI approach. The Agency also 
requested comment on an alternative approach that utilizes benchmark 
sites identified by FDEP. EPA received comments supporting the 
benchmark reference condition approach and the selection of the 90th 
percentile (generally) for deriving the TN and TP criteria. The 
criteria in this final rule are based on a further evaluation and more 
rigorous screening of the benchmark data set of reference sites using 
the population of least-disturbed benchmark sites developed by FDEP and 
further refined by EPA as discussed in the August 2010 supplemental 
notice. EPA concluded that the revised benchmark approach is an 
appropriate reference condition approach for deriving stream criteria 
because it utilizes a quantitative assessment of potential human 
disturbance through the use of surrounding land cover analysis of 
stream corridor and watershed land development indices that provide an 
added dimension to the benchmark approach not considered in EPA's 
proposed SCI site approach. EPA is finalizing stream criteria for most 
NWRs based on the benchmark approach with the addition of supplemental 
data screening steps to ensure that an evaluation of benchmark sites 
utilizes best available information representing reference conditions 
related to least-disturbed as well as and biologically healthy streams 
in the State. For this reason, EPA found the benchmark reference 
condition approach to be a compelling basis to support numeric criteria 
for Florida's streams more closely associated with least-disturbed 
sites. For the West Central region only, EPA is finalizing stream 
criteria based on SCI sites because the benchmark approach resulted in 
the identification of only one WBID as being least-disturbed. EPA found 
the SCI sites provide a more compelling basis to support numeric 
criteria in that region because more data are available at more sites 
that have been identified as biologically healthy, which provide a 
broader representation of nitrogen and phosphorus concentrations within 
this region.
    For this final rule, EPA is using the large amount of high-quality 
scientific data available on TN and TP concentrations with 
corresponding information on land use and human disturbance for a wide 
variety of stream types as part of a reference condition approach to 
derive numeric criteria for Florida's streams. EPA used available data 
that are quantitative measures of land use, indicators of human 
disturbance, and site-specific evaluations of biological condition 
using a multi-metric biological index to identify a population of 
least-disturbed benchmark locations (benchmark sites). EPA used 
associated measurements of TN and TP concentrations from the benchmark 
sites and SCI sites (in the case of the West Central region) as the 
basis for deriving the final numeric criteria for streams.
    The reference condition approach used in this final rule for 
streams consist of three steps: (1) Defining the reference population, 
(2) calculating a distribution of values, and (3) determining 
appropriate thresholds. For the first step as discussed above, EPA used 
the least-disturbed benchmark reference condition approach initially 
developed by FDEP to define the reference condition population, this 
approach starts with a query of FDEP's data in the STORET \93\ (STOrage 
and RETrieval) and GWIS (Generalized Water Information System) 
databases and identified sites with data that met quality assurance 
standards.\94\ Sites with data were then evaluated by FDEP to assess 
the level of human disturbance in the vicinity of the site using the 
Landscape Development Intensity Index (LDI) \95\ to analyze a 100 meter 
distance of land on both sides of and 10 kilometers upstream of each 
stream site (i.e., corridor LDI). Sites with stream corridor LDI scores 
less than or equal to two \96\ were considered sites with relatively 
low potential human disturbance. The group of sites with LDI scores 
less than or equal to two were further reviewed and inspected by FDEP 
based on site visits and aerial photography to assess the degree of 
potential human impact. Based on this review, sites that FDEP 
determined had potential human impact were removed. Sites with mean 
nitrate concentrations greater than 0.35 mg/L, a concentration 
identified by several lines of evidence to result in the growth of 
excessive algae in laboratory studies and extensive field evaluations 
of spring and clear stream sites in Florida \97\ were also removed. 
Following proposal and in response to additional comments and 
information, EPA further evaluated the benchmark sites and screened out 
additional sites with identified nutrient impairments or dissolved 
oxygen impairments according to Florida's 2008 CWA section 303(d) list. 
EPA also removed sites that have available watershed LDI scores greater 
than three as this reflects a higher level of human disturbance on

[[Page 75776]]

a watershed basis.\98\ Finally, EPA removed benchmark sites that have 
available Stream Condition Index (SCI) scores less than 40. These 
additional screens provide greater confidence that the remaining sites 
are both least-disturbed and biologically healthy. The benchmark 
approach resulted in the identification of only one WBID as least-
disturbed within the West Central region. For this reason, EPA is 
utilizing the SCI sites identified at proposal to define the reference 
population for the West Central region in this final rule. EPA grouped 
the remaining sites (hereinafter referred to as ``reference sites'') 
according to its Nutrient Watershed Regions (Panhandle West, Panhandle 
East, North Central, West Central, and Peninsula). For each NWR, EPA 
compiled data (TN and TP concentrations) from the reference sites.
---------------------------------------------------------------------------

    \93\ FL STORET can be found at: http://www.dep.state.fl.us/WATER/STORET/INDEX.HTM.
    \94\ Quality assurance review conducted by FDEP and detailed in 
EPA's accompanying Technical Support Document.
    \95\ Brown, M.T., and M.B. Vivas. 2005. Landscape Development 
Intensity Index. Environmental Monitoring and Assessment 101: 289-
309.
    \96\ Brown, M.T., and M.B. Vivas. 2005. Landscape Development 
Intensity Index. Environmental Monitoring and Assessment 101: 289-
309.
    \97\ See the springs criterion discussion below.
    \98\ The threshold value for watershed LDI is higher than the 
threshold value for the corridor LDI because human disturbance in 
the watershed is known to more weakly influence in-stream nitrogen/
phosphorus concentrations than human disturbance in the stream 
corridor (Peterjohn, W.T. and D. L. Correll. 1984. Nutrient dynamics 
in an agricultural watershed: Observations on the role of a riparian 
forest. Ecology 65: 1466-1475).
---------------------------------------------------------------------------

    The second step in deriving instream protection values was to 
calculate the distribution of nitrogen/phosphorus values of benchmark 
sites within each region. EPA calculated the geometric mean of the 
annual geometric mean of nitrogen/phosphorus concentrations for each 
WBID within which reference sites occurred. EPA provided notice and 
solicited comment on calculating streams criteria on the basis of WBIDs 
in the August 2010 supplemental notice. All samples from reference 
sites within those WBIDs were used to calculate the annual geometric 
mean. The geometric mean of this annual geometric mean for each WBID is 
utilized so that each WBID represents one average concentration in the 
distribution of concentrations for each NWR. Geometric means were used 
for all averages because concentrations were log-normally distributed.
    The third step in deriving instream protection values was to 
determine appropriate thresholds from these distributions to support 
balanced natural populations of aquatic flora and fauna. The upper end 
of the distribution (the 90th percentile) is appropriate if there is 
confidence that the distribution reflects minimally-impacted reference 
conditions and can be shown to be supportive of designated uses (i.e., 
balanced natural populations of aquatic flora and fauna).\99\ EPA 
concluded that the benchmark data set and the resulting benchmark 
distributions of TN and TP were based on substantial evidence of least-
disturbed reference conditions after the additional quality assurance 
screens applied by EPA. This analysis provides EPA with the confidence 
that the benchmark sites are least-disturbed sites and with the 
additional screens applied by the Agency provide a basis for the use of 
the 90th percentile of values from this population to establish the 
final rule criteria. It is appropriate to use the 90th percentile for 
the benchmark distribution because the least-disturbed sites identified 
in Florida that are used to derive the criteria more closely 
approximate minimally-impacted conditions.\100\ For the West Central 
region, where reference sites are identified using the SCI approach, 
there is less confidence that these sites are least-disturbed and 
represent minimally-impacted conditions. As mentioned above, this is 
because this approach does not rely on a quantitative assessment of 
potential human disturbance through the use of surrounding land cover 
analysis of stream corridor and watershed land development indices. 
Therefore, EPA is finalizing the stream criteria in the West Central 
region using the 75th percentile values of the distribution from the 
SCI sites.\101\
---------------------------------------------------------------------------

    \99\ USEPA. 2008. Nutrient Criteria Technical Guidance Manual: 
Wetlands. EPA-822-B-08-001. U.S. Environmental Protection Agency, 
Office of Water, Washington, DC.
    \100\ The 90th percentile is selected so that nitrogen/
phosphorus concentrations that are above the criterion value have a 
low probability (http://www.dep.state.fl.us/water/wqssp/nutrients/docs/tsd_nutrient_crit.docx. Accessed 
October 2010.
---------------------------------------------------------------------------

    EPA's approach in this final rule results in numeric criteria that 
are protective of a balanced natural population of aquatic flora and 
fauna in Florida's streams. EPA has determined, however, that these 
instream values may not always ensure the attainment and maintenance of 
WQS in downstream lakes and that more stringent criteria may be 
necessary to assure compliance with 40 CFR 131.10(b). Therefore, EPA is 
finalizing an approach in this rule for deriving TN and TP values for 
streams to ensure the attainment and maintenance of WQS in downstream 
lakes.\102\ This approach is discussed in Section III.C(2)(f).
---------------------------------------------------------------------------

    \102\ EPA will propose and request comment on the comparable 
issue for deriving TN and TP values for streams to ensure the 
attainment and maintenance of WQS in downstream estuaries as part of 
the coastal and estuarine waters rule on November 14, 2011.
---------------------------------------------------------------------------

(c) Duration and Frequency
    Aquatic life water quality criteria contain three components: 
Magnitude, duration, and frequency. For the numeric TN and TP criteria 
for streams, the derivation of the criterion-magnitude values is 
described above and these values are provided in the table in Section 
III.B(1). The duration component of these stream criteria is specified 
in footnote a of Table B-1 as an annual geometric mean. EPA is 
finalizing the proposed frequency component as a no-more-than-one-in-
three-years excursion frequency for the annual geometric mean criteria 
for streams. These duration and frequency components of the criteria 
are consistent with the data set used to derive these criteria, which 
applied distributional statistics to measures of annual geometric mean 
values from multiple years of record. EPA has determined that this 
frequency of excursions will not result in unacceptable effects on 
aquatic life as it will allow the stream ecosystem enough time to 
recover from occasionally elevated levels of nitrogen/phosphorus in the 
stream.103 104 105 These selected duration and frequency 
components recognize that hydrological variability (e.g., high and low 
flows) will produce variability in nitrogen and phosphorus 
concentrations, and that individual measurements may at times be 
greater than the criteria magnitude concentrations without causing 
unacceptable effects to aquatic organisms and their uses. Furthermore, 
the frequency and duration components balance the representation of 
underlying data and analyses based on the central tendency of many 
years of data with the need to exercise some caution to ensure that 
streams have sufficient time to process individual years of elevated 
nitrogen and phosphorus levels and

[[Page 75777]]

avoid the possibility of cumulative and chronic effects (i.e., the no-
more-than-one-in-three-year component). More information on this 
specific topic is provided in EPA's Final Rule TSD for Florida's Inland 
Waters, Chapter 1: Methodology for Deriving U.S. EPA's Criteria for 
Streams located in the record for this final rule.
---------------------------------------------------------------------------

    \103\ USEPA. 1985. Guidelines for Deriving Numeric National 
Water Quality Criteria for the Protection of Aquatic Organisms and 
Their Uses. EPA PB85-227049. U.S. Environmental Protection Agency, 
Office of Research and Development, Environmental Research 
Laboratories.
    \104\ Hutchens, J. J., K. Chung, and J. B. Wallace. 1998. 
Temporal variability of stream macroinvertebrate abundance and 
biomass following pesticide disturbance. Journal of the North 
American Benthological Society 17:518-534.
    \105\ Wallace, J.B. D. S.Vogel, and T.F. Cuffney. 1986. Recovery 
of a headwater stream from an insecticide induced community 
disturbance. Journal of North American Benthological Society 5: 115-
l 26.
---------------------------------------------------------------------------

d. Reference Condition Approach
    In deriving the final criteria for streams, EPA has relied on a 
reference condition approach, which has been well documented, peer 
reviewed, and developed in a number of different 
contexts.106 107 108 109 110 In the case of Florida, this 
approach is supported by a substantial Florida-specific database of 
high quality information, sound scientific analysis and extensive 
technical evaluation.
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    \106\ USEPA. 2000a. Nutrient Criteria Technical Guidance Manual: 
Lakes and Reservoirs. EPA-822-B-00-001. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC.
    \107\ USEPA. 2000b. Nutrient Criteria Technical Guidance Manual: 
Rivers and Streams. EPA-822-B-00-002. U.S. Environmental Protection 
Agency, Office of Water, Washington, DC.
    \108\ Stoddard, J. L., D. P. Larsen, C. P. Hawkins, R. K. 
Johnson, and R. H. Norris. 2006. Setting expectations for the 
ecological condition of streams: the concept of reference condition. 
Ecological Applications 16:1267-1276.
    \109\ Herlihy, A. T., S. G. Paulsen, J. Van Sickle, J. L. 
Stoddard, C. P. Hawkins, L. L. Yuan. 2008. Striving for consistency 
in a national assessment: the challenges of applying a reference-
condition approach at a continental scale. Journal of the North 
American Benthological Society 27:860-877.
    \110\ U.S. EPA. 2001. Nutrient Criteria Technical Manual: 
Estuarine and Coastal Marine Waters. Office of Water, Washington, 
DC. EPA-822-B-01-003.
---------------------------------------------------------------------------

    EPA received comments regarding the scientific defensibility of the 
reference condition approach, using either the benchmark sites or the 
SCI sites. Many commenters observed that such approaches do not 
mechanistically link biological effects to nitrogen/phosphorus levels 
and therefore assert that EPA cannot scientifically justify numeric 
criteria without an observed biological effect. EPA views the reference 
condition approach as scientifically appropriate to derive the 
necessary numeric criteria in Florida streams. Reference conditions 
provide the appropriate benchmark against which to determine the 
nitrogen and phosphorus concentrations present when the designated use 
is being met. When the natural background concentrations of specific 
parameters can be defined by identifying reference conditions at 
anthropogenically-undisturbed sites, then the concentrations at these 
sites can be considered as sufficient to support the aquatic life 
expected to occur naturally at that site.\111\ Also, setting criteria 
based on the conditions observed in reference condition sites reflects 
both the stated goal of the Clean Water Act and EPA's National Nutrient 
Strategy that calls for States, including Florida, to take protective 
and preventative steps in managing nitrogen/phosphorus pollution to 
maintain the chemical, physical and biological integrity of the 
Nation's waters before adverse biological and/or ecological effects are 
observed.\112\
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    \111\ Davies, T.T., USEPA. 1997, November 5. Memorandum to Water 
Management Division Directors, Regions 1-10, and State and Tribal 
Water Quality Management Program Directors on Establishing Site 
Specific Aquatic Life Criteria Equal to Natural Background.
    \112\ USEPA. 1998. National Strategy for the Development of 
Regional Nutrient Criteria. EPA 822-R-98-002. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC; Grubbs, G., 
USEPA. 2001, November 14. Memorandum to Directors of State Water 
Programs, Directors of Great Water Body Programs, Directors of 
Authorized Tribal Water Quality Standards Programs and State and 
Interstate Water Pollution Control Administrators on Development and 
Adoption of Nutrient Criteria into Water Quality Standards.; 
Grumbles, B.H., USEPA. 2007, May 25.Memorandum to Directors of State 
Water Programs, Directors of Great Water Body Programs, Directors of 
Authorized Tribal Water Quality Standards Programs and State and 
Interstate Water Pollution Control Administrators on Nutrient 
Pollution and Numeric Water Quality Standards.
---------------------------------------------------------------------------

    The effects of TN and TP on an aquatic ecosystem are well 
understood and documented. There is a substantial and compelling 
scientific basis for the conclusion that excess TN and TP will have 
adverse effects on 
streams113 114 115 116 117 118 119 120 121 122 123 124 125 126 127
. As discussed in Section II above, excess nitrogen/phosphorus in 
streams, like other aquatic ecosystems, increase vegetative growth 
(plants and algae), and change the assemblage of plant and algal 
species present in the system. These changes can affect the organisms 
that are consumers of algae and plants by altering the balance of food 
resources available to different trophic levels. For example, excess 
nitrogen/phosphorus promotes the growth of opportunistic and short-
lived plant species that die quickly leaving more dead vegetative 
material available for consumption by lower tropic levels. 
Additionally, excess nitrogen/phosphorus can promote the growth of less 
palatable nuisance algae species that results in less food available 
for filter feeders. These changes can also alter the habitat structure 
by covering the stream or river bed with periphyton (attached algae) 
rather than submerged aquatic plants, or clogging the water column with 
phytoplankton (floating algae). In addition, excess nitrogen/phosphorus 
can lead to the production of algal toxins that can be toxic to fish, 
invertebrates, and humans. Chemical characteristics of the water, such 
as pH and concentrations of dissolved oxygen (DO), can also be affected 
by excess nitrogen/phosphorus leading to low DO conditions and hypoxia. 
Each of these changes can, in turn, lead to other changes in the stream 
community and, ultimately, to changes in the stream ecology that 
supports the overall function of the linked aquatic ecosystem.
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    \113\ Biggs, B.J.F. 2000. Eutrophication of streams and rivers: 
dissolved nutrient-chlorophyll relationships for benthic algae. 
Journal of the North American Benthological Society 19:17-31
    \114\ Bothwell, M.L. 1985. Phosphorus limitation of lotic 
periphyton growth rates: an intersite comparison using continuous-
flow troughs (Thompson River system, British Columbia). Limnology 
and Oceanography 30:527-542
    \115\ Bourassa, N., and A. Cattaneo. 1998. Control of periphyton 
biomass in Laurentian streams (Quebec). Journal of the North 
American Benthological Society 17:420-429
    \116\ Bowling, L.C., and P.D. Baker. 1996. Major cyanobacterial 
bloom in the Barwon-Darling River, Australia, in 1991, and 
underlying limnological conditions. Marine and Freshwater Research 
47: 643-657
    \117\ Cross, W. F., J. B. Wallace, A. D. Rosemond, and S. L. 
Eggert. 2006. Whole-system nutrient enrichment increases secondary 
production in a detritus-based ecosystem. Ecology 87: 1556-1565
    \118\ Dodds, W.K., and D.A. Gudder. 1992. The ecology of 
Cladophora. Journal of Phycology 28:415-427
    \119\ Elwood, J.W., J.D. Newbold, A.F. Trimble, and R.W. Stark. 
1981. The limiting role of phosphorus in a woodland stream 
ecosystem: effects of P enrichment on leaf decomposition and primary 
producers. Ecology 62:146-158
    \120\ Francoeur, S.N. 2001. Meta-analysis of lotic nutrient 
amendment experiments: detecting and quantifying subtle responses. 
Journal of the North American Benthological Society 20: 358-368
    \121\ Moss, B., I. Hooker, H. Balls, and K. Manson. 1989. 
Phytoplankton distribution in a temperate floodplain lake and river 
system. I. Hydrology, nutrient sources and phytoplankton biomass. 
Journal of Plankton Research 11: 813-835
    \122\ Mulholland, P.J. and J.R. Webster. 2010. Nutrient dynamics 
in streams and the role of J-NABS. Journal of the North American 
Benthological Society 29: 100-117
    \123\ Peterson, B.J., J.E. Hobbie, A.E. Hershey, M.A. Lock, T.E. 
Ford, J.R. Vestal, V.L. McKinley, M.A.J. Hullar, M.C. Miller, R.M. 
Ventullo, and G. S. Volk. 1985. Transformation of a tundra river 
from heterotrophy to autotrophy by addition of phosphorus. Science 
229:1383-1386
    \124\ Rosemond, A. D., P. J. Mulholland, and J. W. Elwood. 1993. 
Top-down and bottom-up control of stream periphyton: Effects of 
nutrients and herbivores. Ecology 74: 1264-1280
    \125\ Rosemond, A. D., C. M. Pringle, A. Ramirez, and M.J. Paul. 
2001. A test of top-down and bottom-up control in a detritus-based 
food web. Ecology 82: 2279-2293
    \126\ Rosemond, A. D., C. M. Pringle, A. Ramirez, M.J. Paul, and 
J. L. Meyer. 2002. Landscape variation in phosphorus concentration 
and effects on detritus-based tropical streams. Limnology and 
Oceanography 47: 278-289.
    \127\ Slavik, K., B. J. Peterson, L. A. Deegan, W. B. Bowden, A. 
E. Hershey, J. E. Hobbie. 2004. Long-term responses of the Kuparuk 
River ecosystem to phosphorus fertilization. Ecology 85: 939-954.

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[[Page 75778]]

C. Numeric Criteria for the State of Florida's Lakes

(1) Final Rule
    EPA is promulgating numeric criteria for chlorophyll a, TN and TP 
in three classes of Florida's lakes, classified as Class I or III 
waters under Florida law (Section 62-302.400, F.A.C.):

                              Table C-17--EPA's Numeric Criteria for Florida Lakes
----------------------------------------------------------------------------------------------------------------
                                                          Chl-a (mg/L) \b\
             Lake color \a\ and alkalinity                       *              TN (mg/L)          TP (mg/L)
----------------------------------------------------------------------------------------------------------------
Colored Lakes \c\......................................             0.020               1.27               0.05
                                                                                 [1.27-2.23]        [0.05-0.16]
Clear Lakes, High Alkalinity \d\.......................             0.020               1.05               0.03
                                                                                 [1.05-1.91]        [0.03-0.09]
Clear Lakes, Low Alkalinity \e\........................             0.006               0.51               0.01
                                                                                 [0.51-0.93]        [0.01-0.03]
----------------------------------------------------------------------------------------------------------------
\a\ Platinum Cobalt Units (PCU) assessed as true color free from turbidity.
\b\ Chlorophyll a is defined as corrected chlorophyll, or the concentration of chlorophyll a remaining after the
  chlorophyll degradation product, phaeophytin a, has been subtracted from the uncorrected chlorophyll a
  measurement.
\c\ Long-term Color > 40 Platinum Cobalt Units (PCU).
\d\ Long-term Color  20 mg/L CaCO3.
\e\ Long-term Color L CaCO3.
* For a given waterbody, the annual geometric mean of chlorophyll a, TN or TP concentrations shall not exceed
  the applicable criterion concentration more than once in a three-year period.

    For each class of water defined by color and alkalinity, the 
applicable criteria are the values in bold for chlorophyll a, TN and 
TP. The criteria framework provides flexibility for FDEP to derive 
lake-specific, modified TN and TP criteria if the annual geometric mean 
chlorophyll a concentration is less than the criterion for an 
individual lake in each of the three immediately preceding years. In 
such a case, the corresponding criteria for TN and/or TP may be 
modified to reflect maintenance of ambient conditions within the range 
specified in the parenthetical below each baseline TN and TP criteria 
printed in bold in Table C-1 above. Modified criteria for TN and/or TP 
must be based on data from at least the immediately preceding three 
years \128\ in a particular lake. Modified TN and/or TP criteria may 
not be greater than the higher value specified in the range. Modified 
TN and/or TP criteria for a lake also may not be above criteria 
applicable to streams to which a lake discharges in order to ensure the 
attainment and maintenance of downstream water quality standards.
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    \128\ The previous three years of data are required as a basis 
for modifying TN and TP criteria and must meet FDEP's data quality 
assurance objectives. Additional historical data may be used to 
augment the three years of data characterizing the lake's annual and 
inter-annual variability. Only historical data containing data for 
all three parameters can be used and the data must meet FDEP's data 
quality assurance objectives.
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    Utilization of the range flexibility in the numeric lake criteria 
in this final rule requires that the ambient calculation for modified 
TN and TP criteria be based on: (1) The immediately preceding three-
year record of observation for each parameter,\129\ (2) representative 
sampling during each year (at least one sample in May-September and at 
least one sample in October-April), and (3) a minimum of 4 samples from 
each year. Requiring at least three years of data accounts for year-to-
year hydrological variability, ensures longer-term stable conditions, 
and appropriately accounts for anomalous conditions in any given year 
that could lead to erroneous conclusions regarding the true 
relationship between nitrogen/phosphorus and chlorophyll a levels in a 
lake. Representative samples from each year minimize the effects of 
seasonal variations in nitrogen/phosphorus and chlorophyll a 
concentrations. Finally, the minimum sample size of 4 samples per year 
allows estimates of reliable geometric means while still maintaining a 
representative sample of lakes. The State shall notify EPA Region 4 and 
provide the supporting record within 30 days of determination of 
modified lake criteria.
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    \129\ As noted above, if more than three years of data are 
available for each parameter, then more data can be used.
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    To ensure attainment of applicable downstream lake criteria, this 
final rule provides a tiered approach for adjusting instream criteria 
presented in section III.B.(1) above for those streams that flow into 
lakes.\130\ Where site-specific data on lake characteristics are 
available, the final rule provides a modeling approach for the 
calculation of downstream lake protection values that relies upon the 
use of the BATHTUB model.\131\ In circumstances where sufficient site-
specific lake data are readily available and either EPA or FDEP 
determine that another scientifically defensible model is more 
appropriate (e.g., the Water Quality Analysis Simulation Program, or 
WASP), the modeling approach accommodates use of a scientifically 
defensible alternative. In the absence of models, other approaches for 
ensuring protection of downstream lakes are provided and described 
further below.
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    \130\ Approximately 30% of Florida lakes are fed by streams to 
which this DPV analysis would apply (Schiffer, Donna M. 1998. 
Hydrology of Central Florida Lakes--A Primer. U.S. Geological Survey 
in cooperation with SJWMD and SFWMD: Circular 1137).
    \131\ Kennedy, R.H. 1995. Application of the BATHTUB model to 
Selected Southeastern Reservoirs. Technical Report EL-95-14. U.S. 
Army Engineer Waterways Experiment Station, Vicksburg, MS.; Walker, 
W.W., 1985. Empirical Methods for Predicting Eutrophication in 
Impoundments; Report 3, Phase II: Model Refinements. Technical 
Report E-81-9. U.S. Army Engineer Waterways Experiment Station, 
Vicksburg, MS.; Walker, W.W., 1987. Empirical Methods for Predicting 
Eutrophication in Impoundments; Report 4, Phase III: Applications 
Manual. Technical Report E-81-9. U.S. Army Engineer Waterways 
Experiment Station, Vicksburg, MS.
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(2) Background and Analysis
(a) Methodology for Lake Classification
    In the January 2010 proposal, EPA used color and alkalinity to 
classify Florida's lakes based on substantial data demonstrating that 
these characteristics influence the response of lakes to increased 
nitrogen/phosphorus and the expected background chlorophyll a 
concentration. Many of Florida's lakes contain dissolved organic matter 
leached from surface vegetation that

[[Page 75779]]

colors the water. More color in a lake limits light penetration within 
the water column, which in turn limits algal growth. Thus, in lakes 
with colored water, higher levels of nitrogen/phosphorus may occur 
without exceeding the chlorophyll a criteria concentrations. EPA 
evaluated relationships among TN, TP, and chlorophyll a concentration 
data, and found that lake color influenced these relationships. More 
specifically, EPA found the correlations between nitrogen/phosphorus 
and chlorophyll a concentrations to be stronger and less variable when 
lakes were categorized into two distinct groups based on a color 
threshold of 40 PCU, with clear lakes demonstrating more algal growth 
with increased nitrogen/phosphorus, as would be predicted by the 
increased light penetration. This threshold is consistent with the 
distinction between clear and colored lakes long observed in 
Florida.\132\
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    \132\ Shannon, E.E., and P.L. Brezonik. 1972. Limnological 
characteristics of north and central Florida lakes. Limnology and 
Oceanography 17(1): 97-110.
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    Within the clear lakes category, color is not the dominant 
controlling factor in algal growth. For these clear lakes, EPA proposed 
the use of alkalinity as an additional distinguishing characteristic. 
Alkalinity and pH increase when water is in contact with carbonate 
rocks, such as limestone, or limestone-derived soil in the State of 
Florida. Limestone is also a natural source of phosphorus, and thus, in 
Florida, lakes that are higher in alkalinity are often associated with 
naturally elevated TP levels. The alkalinity (measured as 
CaCO3 concentration) of Florida clear lakes ranges from zero 
to over 200 mg/L. EPA proposed classifying clear Florida lakes into 
acidic and alkaline classes based on an alkalinity threshold of 50 mg/L 
CaCO3, and solicited comment on whether a 20 mg/L 
CaCO3 threshold would be more appropriate. EPA received 
comments noting that that the lower alkalinity classification threshold 
would be more representative of naturally oligotrophic conditions by 
creating a class of lakes with very low alkalinity and correspondingly 
low chlorophyll a concentrations. After reviewing available lake data, 
EPA found that clear lakes below 20 mg/L CaCO3 were more 
similar to one another in terms of naturally expected chlorophyll a, 
TN, and TP concentrations than clear lakes below 50 mg/L 
CaCO3. Thus, EPA concluded that an alkalinity threshold of 
20 mg/L CaCO3 was an appropriate threshold for classifying 
clear lakes and EPA is finalizing the lower alkalinity threshold in 
this rule. More information on this specific topic is provided in EPA's 
Finals TSD for Florida's Inland Waters, Chapter 2: Methodology for 
Deriving U.S. EPA's Criteria for Lakes located in the record for this 
final rule.
    EPA also proposed the use of specific conductance as a surrogate 
for alkalinity. EPA received comments that conductivity was not an 
accurate surrogate measure for alkalinity. EPA evaluated the 
association between specific conductivity and alkalinity and concluded 
that alkalinity is a preferred parameter for lake classification 
because it is a more direct measure of the presence of carbonate rocks, 
such as limestone that are associated with natural elevated phosphorus 
levels. Changes in specific conductivity can be attributed to changes 
in alkalinity, but in many cases may be caused by increases in the 
concentrations of other compounds that originate from human activities. 
Thus, EPA has concluded that alkalinity is a more reliable indicator 
for characterizing natural background conditions for Florida lakes.
    A number of comments suggested EPA consider a system that 
delineates 47 lake regions and a system that classifies lakes as a 
continuous function of both alkalinity and color. As discussed in more 
detail in the TSD supporting this final rule, EPA evaluated each of 
these alternative classification approaches, and found that they did 
not improve the predictive accuracy of biological responses to 
nitrogen/phosphorus over EPA's classification, nor result in a 
practical system that can be implemented by FDEP. For example, in the 
case of the 47 lake region approach, insufficient data are available to 
derive numeric criteria across all of the 47 regions and in the case of 
the continuous function approach there is a reliance on an assumption 
that TN and TP are always co-limiting that is not always true.\133\
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    \133\ Guildford, S. J. and R. E. Hecky. 2000. Total nitrogen, 
total phosphorus, and nutrient limitation in lakes and oceans: Is 
there a common relationship? Limnology and Oceanography 45: 1213-
1223.
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    A number of commenters suggested that lake-specific criteria would 
be more appropriate than the three broad classes that EPA proposed. The 
substantial data available in the record for this final rule supports 
the conclusion that many of Florida's lakes share similar physical, 
chemical, and geological characteristics, which in turn justifies, 
based on sound scientific evidence, broad classification of Florida 
lakes. EPA concluded, based on the substantial data and associated 
analysis explained above, that color and alkalinity are primary 
distinguishing factors in Florida lakes with respect to nitrogen/
phosphorus dynamics and the associated biological response. With 
respect to consideration of site-specific information that goes beyond 
the detailed site-specific sampling and monitoring analysis already 
discussed,\134\ the numeric lake criteria in this final rule are 
established within a flexible regulatory framework that allows 
adjustment of TN, TP, and/or chlorophyll a criteria based on additional 
lake-specific data. This framework provides an opportunity to derive 
lake-specific criteria similar to the manner suggested in public 
comment, where lake-specific data and information are available, while 
ensuring that numeric criteria are in place to protect all of Florida's 
lakes. Further site-specific flexibility is provided in this final rule 
through the derivation of alternative criteria by a Federal Site 
Specific Adjusted Criteria (SSAC) process discussed in more detail 
below in Section V.C.
---------------------------------------------------------------------------

    \134\ Technical Support Document for EPA's Final Rule for 
Numeric Nutrient Criteria for Nitrogen/Phosphorus Pollution in 
Florida's Inland Surface Fresh Waters.
---------------------------------------------------------------------------

    In this final rule, EPA is dividing Florida's lakes into three 
classes: (1) Colored Lakes >40 Platinum Cobalt Units (PCU), (2) Clear, 
High Alkalinity Lakes (20 mg/L calcium 
carbonate (CaCO3)), and (3) Clear, Low Alkalinity Lakes 
(L CaCO3). These two 
parameters, color and alkalinity, both affect lake productivity and 
plant biomass, as measured by chlorophyll a. For more information 
regarding these classes, please refer to EPA's Final Rule TSD for 
Florida's Inland Waters, Chapter 2: Methodology for Deriving U.S. EPA's 
Criteria for Lakes.
(b) Methodology for Chlorophyll  a Criteria
    EPA proposed the use of chlorophyll a concentration as an indicator 
of a healthy biological condition, supportive of natural balanced 
populations of aquatic flora and fauna in each of the classes of 
Florida's lakes. Excess algal growth is associated with degradation in 
aquatic life, and chlorophyll a levels are a measure of algal growth. 
To derive the proposed chlorophyll a concentrations that would be 
protective of natural balanced populations of aquatic flora and fauna 
in Florida's lakes, EPA utilized the expected trophic status of the 
lake, based on internationally accepted lake use classifications.\135\
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    \135\ OECD. 1982. Eutrophication of Waters. Monitoring, 
Assessment and Control. Organisation for Economic Development and 
Co-Operation, Paris, France.

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[[Page 75780]]

    As discussed in more detail at proposal, lakes can be classified 
into one of three trophic State categories (i.e., oligotrophic, 
mesotrophic, eutrophic).\136\ EPA concluded at proposal that healthy 
colored lakes and clear, high alkalinity lakes should maintain a 
mesotrophic status, because they receive significant natural nitrogen/
phosphorus input and still support a healthy diversity of aquatic life 
in warm, productive climates such as Florida. For these two categories 
of lakes, EPA proposed a chlorophyll a criterion of 0.020 mg/L to 
support balanced natural populations of aquatic life flora and fauna. 
At concentrations above 0.020 mg/L chlorophyll a, the trophic status of 
the lake is more likely to become eutrophic and the additional 
chlorophyll a will reduce water clarity, negatively affecting native 
submerged macrophytes, and the invertebrate and fish communities that 
depend on them. Commenters suggested that this threshold is overly 
protective of naturally eutrophic lakes in the State. For those lakes 
that may currently be naturally eutrophic, this final rule contains a 
formal SSAC process to revise these criteria for this unique type of 
lake. For more information on the SSAC process, please refer to Section 
V.C of this final rule.
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    \136\ Trophic state describes the nitrogen/phosphorus levels and 
algal state of an aquatic system: Oligotrophic (low nitrogen/
phosphorus and algal productivity), mesotrophic (moderate nitrogen/
phosphorus and algal productivity), and eutrophic (high nitrogen/
phosphorus and algal productivity).
---------------------------------------------------------------------------

    In contrast, clear, low alkalinity lakes in Florida do not receive 
natural nitrogen/phosphorus input from underlying geological formations 
in the watershed and thus, they support less algal growth and have 
lower chlorophyll a levels than colored or clear, high alkalinity 
lakes. EPA concluded at proposal that these lakes should maintain an 
oligotrophic status to support balanced natural populations of aquatic 
flora and fauna. EPA proposed a chlorophyll a criterion of 0.006 mg/L 
in clear, low alkalinity lakes to support balanced natural populations 
of aquatic life flora and fauna. At concentrations above 0.006 mg/L 
chlorophyll a, the trophic status of the lake is more likely to become 
mesotrophic and the additional chlorophyll a will reduce water clarity, 
negatively affecting native submerged macrophytes, and the invertebrate 
and fish communities that depend on them. Commenters suggested that 
this chlorophyll a concentration may not be appropriate for clear lakes 
with alkalinity less than 50 mg/L. As explained in more detail above, 
in this final rule EPA concluded that 20 mg/L is an appropriate 
threshold between low and high alkalinity lakes. Thus, lakes with 
alkalinity greater than 20 mg/L will have a chlorophyll a criterion 
that is applicable to clear, high alkalinity lakes. Based on the 
revision of the alkalinity threshold to 20 mg/L, EPA reviewed the 
available chlorophyll a data for clear, low alkalinity lakes and found 
that the majority of lakes have chlorophyll a concentrations less than 
0.006 mg/L reflective of oligotrophic conditions which leads EPA to 
conclude that this chlorophyll a concentration will serve to maintain 
the trophic status of these lakes.
    In this final rule, EPA is promulgating chlorophyll a criteria of 
0.020 mg/L in colored lakes and clear, high alkalinity lakes and a 
chlorophyll a criterion of 0.006 mg/L in clear, low alkalinity lakes as 
an indicator of a healthy biological condition, supportive of natural 
balanced populations of aquatic flora and fauna in these classes of 
Florida's lakes. For more information regarding these chlorophyll a 
criteria, please refer to EPA's Final Rule TSD for Florida's Inland 
Waters, Chapter 2: Methodology for Deriving U.S. EPA's Criteria for 
Lakes.
(c) Methodology for Total Nitrogen (TN) and Total Phosphorus (TP) 
Criteria in Lakes
    EPA proposed TN and TP criteria for each of the classes of lakes 
described in Section III.C(2)(a) based on the response of chlorophyll a 
to increases in TN and TP for clear and colored lakes in Florida. These 
responses were quantitatively estimated with linear regressions. Each 
data point used in estimating the statistical relationships was the 
geometric mean of samples taken over the course of a year in a 
particular Florida lake. Statistical analyses of these relationships 
showed that the chlorophyll a responses to changes in TN and TP 
differed for colored versus clear lakes, as would be expected, because 
color blocks light penetration in the water column and limits algal 
growth. These analyses also showed that chlorophyll a responds to 
changes in TN and TP in high and low alkalinity clear lakes similarly, 
as would be expected, because alkalinity does not affect light 
penetration. These relationships were used to derive TN and TP criteria 
that would maintain chlorophyll a concentrations at desired levels 
known to be supportive of balanced natural populations of aquatic flora 
and fauna as discussed above. These analyses are explained in more 
detail in EPA's Final Rule TSD for Florida's Inland Waters, Chapter 2: 
Methodology for Deriving U.S. EPA's Criteria for Lakes included in the 
record for this final rule.
    EPA proposed baseline TN and TP criteria based on the 75th 
percentile of the predicted distribution of chlorophyll a 
concentrations, given a TN or TP concentration. Commenters suggested 
alternative approaches for deriving TN and TP criteria, including using 
either the mean predicted chlorophyll a concentration, using the 25th 
percentile of the predicted distribution of chlorophyll a 
concentrations, and using an additional criterion based on a higher 
percentile that is associated with a different exceedance frequency. 
EPA considered these alternative approaches and concluded that 
calculating the TN and TP criteria as a baseline concentration with an 
associated concentration range was a more flexible approach than a 
single value approach manifested as the TN and TP concentration 
associated with a specific chlorophyll a concentration. Thus, the 
approach included in this final rule takes into account the natural 
variability observed in different classes of lakes (i.e., colored or 
clear) in a way that a single value approach based on the regression 
line or the lower value of the 50th percentile prediction interval does 
not.
    In this final rule, the TN and TP criteria are based on linear 
regressions (i.e., best-fit lines) predicting the annual geometric mean 
chlorophyll a concentration as a function of the annual geometric mean 
TN or TP. Baseline TN and TP criteria are calculated as the point at 
which the 75th percentile of the predicted distribution of chlorophyll 
a concentrations from the regression relationship is equivalent to the 
chlorophyll a criterion for the appropriate lake class. The range of 
values in the predicted distribution of chlorophyll a concentrations 
arises from small differences in the nitrogen/phosphorus-chlorophyll a 
relationships across different lakes and variability in these 
relationships between years in the same lake. Hence, TN and TP criteria 
are based on the 75th percentile that will be protective at the 
majority of lakes and in the majority of years.
    The predicted distribution of chlorophyll a concentrations for 
lakes differs inherently from the distribution of TN and TP 
concentrations calculated from reference sites for criteria for Florida 
streams (Section III.B(2)(b)). In the case of the criteria for Florida 
streams for most NWRs, benchmark sites represent a population of least-

[[Page 75781]]

disturbed sites and the criteria based on the 90th percentile of 
nitrogen and phosphorus concentrations from these sites are selected to 
characterize the upper bound of nitrogen/phosphorus concentrations that 
one would expect from such sites. Criteria for Florida lakes rely on a 
predictive relationship between nitrogen/phosphorus and chlorophyll a 
concentrations, and the 75th percentile is selected from the 
distribution of chlorophyll a concentrations predicted for specific 
concentrations of TN and TP. As discussed above, basing criteria on 
this percentile provides a means of accounting for variability in 
chlorophyll a concentrations predicted for a given TN and TP 
concentration. In short, the percentile for the streams criteria is 
selected to ensure that nitrogen/phosphorus concentrations in all 
streams are at least as low as those observed in reference streams, 
whereas the percentile for the lakes criteria is selected such that 
concentrations appropriately account for variability in the 
relationships between nitrogen/phosphorus and chlorophyll a 
concentrations.
(d) Duration and Frequency
    Aquatic life water quality criteria include magnitude, duration, 
and frequency components. For the chlorophyll a, TN, and TP criteria 
for lakes, the criterion-magnitude values, expressed as a 
concentration, are provided in Table C-1 in bold. The criterion-
duration of this magnitude is specified in a footnote to this Table as 
an annual geometric mean. EPA is finalizing the criterion-frequency as 
a no-more-than-once-in-three-years excursion frequency of the annual 
geometric mean criteria for lakes. The duration component of the 
criteria is based on annual geometric means to be consistent with the 
data set used to derive these criteria, which applied stressor-response 
relationships based on annual geometric means for individual years at 
individual lakes. These selected duration and frequency components 
recognize that hydrological variability (e.g., high and low flows) will 
produce variability in nitrogen and phosphorus concentrations, and that 
individual measurements may at times be greater than the criterion-
magnitude concentrations without causing unacceptable effects to 
aquatic organisms and their uses. Furthermore, they balance the 
representation of the central tendency of the predicted relationship 
between TN or TP and chlorophyll a based from many years of data with 
the need to exercise some caution to ensure that lakes have sufficient 
time to process individual years of elevated nitrogen and phosphorus 
concentrations and avoid the possibility of cumulative and chronic 
effects (i.e., the no-more-than-one-in-three-year component). 
Additionally, because nitrogen/phosphorus pollution is best managed on 
a watershed basis, this is the same frequency and duration used in the 
final streams criteria. More information on this specific topic is 
provided in EPA's Final Rule TSD for Florida's Inland Waters, Chapter 
2: Methodology for Deriving U.S. EPA's Criteria for Lakes located in 
the record for this final rule.
(e) Application of Lake-Specific, Ambient Condition-Based Modified TN 
and TP Criteria
    EPA proposed an accompanying approach that the State could use to 
adjust TN and TP criteria for a particular lake within a certain range 
where sufficient data on long-term ambient chlorophyll a, TN and TP 
levels are available to demonstrate that protective chlorophyll a 
criterion for a specific lake will still be maintained and a balance of 
natural populations of aquatic flora and fauna will be supported. This 
approach allows for readily available site-specific data to be taken 
into account in the expression of TN and TP criteria, while still 
ensuring support of balanced natural populations of aquatic flora and 
fauna by maintaining the associated chlorophyll a level at or below the 
chlorophyll a criterion level. The scientific premise for the lake-
specific ambient calculation provision for modified TN and/or TP 
criteria is that if ambient lake data show that a lake's chlorophyll a 
levels are at or below the established criteria (i.e., magnitude) for 
at least the last three years and its TN and/or TP levels are within 
the lower and upper bounds, then those ambient levels of TN and TP 
represent conditions that will continue to support the specified 
chlorophyll a response level. The lower bound of the range is based on 
the TN/TP values that correspond to the 75th percentile of the 
predicted chlorophyll a distribution and the upper bound of the range 
is based on the TN/TP values that correspond to the 25th percentile of 
the same predicted distribution. The use of the 25th and 75th 
percentiles accounts for the majority of variability that may occur 
around the central tendency of the predicted relationship between TN or 
TP and chlorophyll a.
    This final rule provides that FDEP must establish and document 
these modified criteria in a manner that clearly recognizes their 
status as the applicable criteria for a particular lake. To this end, 
FDEP must submit a letter to EPA Region 4 formally documenting the use 
of modified criteria as the applicable criteria for particular lakes. 
This final rule allows for a one-time adjustment without a requirement 
that FDEP go through a formal SSAC process. EPA believes that such 
modified TN and TP criteria do not need to go through the SSAC process 
because the conditions under which they are applicable are clearly 
stated in this final rule and data requirements are clearly laid out so 
that the outcome is clear, consistent, transparent, and reproducible. 
By providing a specific process for deriving modified criteria within 
the WQS rule itself, each individual outcome of this process is an 
effective WQS for CWA purposes and does not need separate adoption by 
FDEP or approval by EPA. For more information on the SSAC process, 
please refer to Section V.C of this final rule.
    Application of the ambient calculation provision has implications 
for assessment and permitting because the outcome of applying this 
provision is to establish alternate numeric TN and/or TP values as the 
applicable lake criteria. For accountability and tracking purposes, the 
State must document the result of the ambient calculation for any given 
lake. Once modified criteria are established under this approach, they 
remain the applicable criteria for the long-term for purposes of 
implementing the State's water quality program until they are 
subsequently modified either through the Federal SSAC process or State 
revision to the applicable WQS, which has been approved by EPA pursuant 
to CWA section 303(c).
    This site-specific lake criteria adjustment provision is subject to 
the downstream protection requirements more broadly discussed below. 
Thus in a comparable manner this final rule provides that calculated TN 
and/or TP values in a lake that discharges to a stream may not exceed 
criteria applicable to the stream to which a lake discharges.
(f) Downstream Protection of Lakes
    In developing the proposed stream criteria, EPA also evaluated 
their effectiveness for assuring the protection of downstream lake 
water quality standards pursuant to the provisions of 40 CFR 130.10(b), 
which requires that WQS must provide for the attainment and maintenance 
of the WQS of downstream waters.\137\ EPA's criteria for

[[Page 75782]]

lakes are, in some cases, more stringent than the final criteria for 
streams that flow into the lakes, and thus the instream criteria may 
not be stringent enough to ensure protection of WQS in certain 
downstream lakes. As a result, EPA proposed application of the 
Vollenweider equation to ensure that the TP criteria in streams are 
protective of downstream lakes, and requested comment on alternative 
approaches such as the BATHTUB model and whether there should be an 
allowance for use of other models that are demonstrated to be 
protective and scientifically defensible.
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    \137\ EPA will assess the effectiveness of final stream criteria 
for assuring the protection of downstream estuaries in a separate 
rulemaking that focuses on estuarine and coastal waters to be 
proposed by November 14, 2011 and finalized by August 15, 2012.
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    The proposed use of the Vollenweider model equation to ensure the 
protection of downstream lakes requires input of two lake-specific 
characteristics: the fraction of inflow due to stream flow and the 
hydraulic retention time. EPA provided alternative preset values for 
percent contribution from stream flow and hydraulic retention time that 
could be used in those instances where lake-specific input values are 
not readily available. EPA's January 2010 proposed rule discussed the 
flexibility for the State to use site-specific inputs to the 
Vollenweider equation for these two parameters, as long as the State 
determines that such inputs are appropriate and documents the site-
specific values. Some commenters stated that the Vollenweider equation 
is overly simplistic and does not include the necessary factors to 
account for physical, hydrologic, chemical, and biological processes 
necessary to determine protective criteria. Several commenters also 
suggested the need for TN values to protect downstream lakes that are 
nitrogen-limited (such as many of the lakes in the phosphorus-rich 
areas of the State). Comments included a recommendation to use models 
that can better represent site-specific conditions, such as BATHTUB.
    EPA's August 2010 Supplemental Notice of Data Availability and 
Request for Comment requested additional comment on using the BATHTUB 
model in place of the Vollenweider equation for deriving both TP and TN 
criteria to protect downstream lakes, allowing the use of alternative 
models under certain circumstances, and providing for an alternative 
approach to protect downstream lakes when limited data are available 
that would use the lake criteria themselves as criteria for upstream 
waters flowing into the lake.
    In the final rule, protection of downstream lakes is accomplished 
through establishment of a downstream protection value (DPV). The 
applicable criteria for streams that flow into downstream lakes include 
both the instream criteria for TN and TP and the DPV, which is a 
concentration or loading value at the point of entry into a lake that 
results in attainment of the lake criteria. EPA selected the point of 
entry into the lake, also referred to as the ``pour point,'' as the 
location to measure water quality because the lake responds to the 
input from the pour point and all contributions from the stream network 
above this point in a watershed affect the water quality at the pour 
point. When a DPV is exceeded at the pour point, the waters that 
collectively comprise the network of streams in the watershed above 
that pour point are considered to not attain the DPV for purposes of 
section 303(d) of the Clean Water Act. The State may identify these 
impaired waters as a group rather than individually.
    It is appropriate to express the DPV as either a load or 
concentration (load divided by flow) because both are expressions of 
the amount of TN and TP that are delivered to the downstream water. In 
an expression of load, the amount is expressed directly as mass per 
time (e.g., pounds per year), whereas a concentration expresses the 
amount in terms of the mass contained in a particular volume of water 
(e.g., milligrams per liter). Either expression may be used for 
assessment and source control allocation purposes. Calculating a DPV as 
a load will require modeling or other technical information, such as a 
TMDL, that accounts for both the volume of the receiving water and the 
flow contributed through the pour point. A DPV expressed as a 
concentration may be based on a model or TMDL or may reflect a TN or TP 
level that corresponds to a TN, TP, or chlorophyll a concentration that 
protects the lake.
    Contributions of TN and/or TP from sources in stream tributaries 
upstream of the point of entry are accountable to the DPV because the 
water quality in the stream tributaries must result in attainment of 
the DPV at the pour point into the lake. The spatial allocation of load 
within the watershed is an important accounting step to ensure that the 
DPV is achieved at the point of entry into the lake. How the watershed 
load is allocated may differ based on watershed characteristics and 
existing sources (e.g., areas that are more susceptible to physical 
loss of nitrogen; location of towns, farms, and dischargers), so long 
as the DPV is met at the point of entry into the downstream lake. Where 
additional information is available, watershed modeling could be used 
to develop allocations that reflect hydrologic variability and other 
water quality considerations. For protection of the downstream lake, 
what is important is an accounting for nutrient loadings on a watershed 
scale that results in meeting the DPV at the point of entry into the 
downstream lake.
    The final rule provides that additional DPVs may be established in 
upstream locations to represent sub-allocations of the total allowable 
loading or concentration. Such sub-allocations may be useful where 
there are differences in hydrological conditions and/or sources of TN 
and/or TP in different parts of the watershed. The rule specifies that 
DPVs apply to stream tributaries up to the point of reaching a 
waterbody that is not a stream as defined in the rule (e.g., up to 
reaching another lake in a ``nested'' or chain of lakes situation). The 
rule also includes an option, however, to establish a DPV to account 
for a larger watershed area in a modeling context. Establishing DPVs 
that apply to a larger watershed may be useful to address a situation 
where the water that is furthest downstream in a watershed is also the 
water that is most sensitive to nitrogen/phosphorus pollution. That 
situation may require a more equitable distribution, across the larger 
watershed, of the load that protects the most sensitive waterbody.
    Where multiple tributaries enter a lake, the total allowable 
loading to the lake may be distributed among the tributaries for 
purposes of DPV calculation in any manner that results in meeting the 
total allowable loading for the lake, remembering that those 
tributaries are also subject to the instream protection value 
established for the tributaries.
    Where sufficient data and information are available, DPVs may be 
established through application of the BATHTUB model. BATHTUB applies 
empirical models to morphometrically complex lakes and reservoirs. The 
model performs steady-state water and nutrient balance calculations, 
uses spatially segmented hydraulic networks, and accounts for advective 
and diffusive transport of nutrients. When properly calibrated and 
applied, BATHTUB predicts nutrient-related water quality conditions 
such as TP, TN, and chlorophyll a concentrations, transparency, and 
hypolimnetic oxygen depletion rates. The model can apply to a variety 
of lake sizes, shapes and transport characteristics. A high degree of 
flexibility is available for specifying

[[Page 75783]]

model segments as well as multiple influent streams. Because water 
quality conditions are calculated using relationships derived from data 
specific to each lake, BATHTUB accounts for differences between lakes, 
such as the rate of internal loading of phosphorus from bottom 
sediments. The above descriptive information is summarized from 
available technical references that also describe the model and its 
applications in greater detail.138 139 140 EPA believes 
BATHTUB is appropriate for DPV calculations because BATHTUB can 
represent a number of site-specific variables that may influence 
nutrient responses and can estimate both TN and TP concentrations at 
the pour points to protect the receiving lake. BATHTUB has been 
previously used for lake water quality management purposes, such as the 
development of TMDLs in States, including Florida. This model was 
selected because it does not have extensive data requirements, yet it 
provides for the capability to be calibrated based on observed site-
specific lake data and it provides for reliable estimates that will 
ensure the protection of downstream lakes.
---------------------------------------------------------------------------

    \138\ Walker, W.W., 1981. Empirical Methods for Predicting 
Eutrophication in Impoundments; Report 1, Phase I: Data Base 
Development. Technical Report E-81-9. U.S. Army Engineer Waterways 
Experiment Station, Vicksburg, MS.
    \139\ Walker, W.W., 1982. Empirical Methods for Predicting 
Eutrophication in Impoundments; Report 2, Phase II: Model Testing. 
Technical Report E-81-9. U.S. Army Engineer Waterways Experiment 
Station, Vicksburg, MS.
    \140\ Walker, W.W., 1999. Simplified Procedures for 
Eutrophication Assessment and Prediction: User Manual; Instruction 
Report W-96-2. U.S. Army Corps of Engineers Waterways Experiment 
Station, Vicksburg, MS.
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    EPA's final rule also specifically authorizes FDEP or EPA to use a 
model other than BATHTUB when either FDEP or EPA determines that it 
would be appropriate to use another scientifically defensible modeling 
approach that results in the protection of downstream lakes. While 
BATHTUB is a peer-reviewed and versatile model, there are other models 
that, when appropriately calibrated and applied, can offer additional 
capability to address complex situations with an even greater degree of 
site-specificity. Adopted and approved TMDLs may contain sufficient 
information to support derivation of a DPV when the TMDL is based on 
relevant data, defensible science, and accurate analysis.
    As discussed in more detail in the Agency's August 2010 
Supplemental Notice of Data Availability and Request for Comment on 
this issue, one example of an alternative model that FDEP or EPA might 
consider using for particularly complex site-specific conditions is the 
Water Quality Analysis Simulation Program (WASP) model. This model 
allows users to conduct detailed simulations of water quality responses 
to natural and manmade pollutant inputs. WASP is a dynamic compartment-
modeling program for aquatic systems, including both the water column 
and the underlying benthos. WASP allows the user to simulate systems in 
1, 2, or 3 dimensions, and a variety of pollutant types. The model can 
represent time varying processes of advection, dispersion, point and 
diffuse mass loading, and boundary exchange. WASP also can be linked 
with hydrodynamic and sediment transport models that can provide flows, 
depths, velocities, temperature, salinity and sediment fluxes. The 
above summary information as well as additional technical information 
may be found at http://www.epa.gov/athens/wwqtsc/html/wasp.html. Like 
BATHTUB, WASP has also been previously used for lake water quality 
management purposes, such as TMDLs, nationally and in the State of 
Florida. This model is different from BATHTUB because it does have 
extensive data requirements that allow for the capability to be finely 
calibrated based on observed site-specific lake data, but is similar to 
BATHTUB in that it also provides for reliable estimates that will 
ensure the protection of downstream lakes.
    EPA is finalizing a provision in this section of the rule for 
situations where data are not readily available to derive TN and/or TP 
DPVs using BATHTUB or another scientifically defensible model. In that 
situation, the rule describes how DPVs are determined where the 
downstream lake is attaining the lake criteria and where the downstream 
lake is either not assessed or is impaired.
    Where sufficient information is not available to derive TN and/or 
TP DPVs using BATHTUB or another scientifically defensible technical 
model and the lake attains the applicable criteria, the DPVs would be 
the associated ambient instream levels of TN and/or TP at the point of 
entry into the lake. As long as the TN and TP concentrations necessary 
to support a balanced natural population of aquatic flora and fauna in 
the downstream lake are maintained in the inflow from streams, this 
approach will provide adequate protection of downstream lakes and would 
be used as the applicable DPVs in the absence of readily available data 
to support derivation of TN and TP DPVs using BATHTUB or another 
scientifically defensible technical model such as WASP.
    EPA's final rule provides that when the DPV is based on the ambient 
condition associated with attainment of criteria in the downstream 
lake, degradation in water quality from those established levels would 
be considered impairment, unless the State or EPA revises the DPV using 
a modeling approach or TMDL to show that higher levels of nutrient 
contribution from the tributaries would still result in attainment of 
applicable lake criteria. This provision is not intended to limit 
growth and/or development in the watershed, nor intended to maintain 
current conditions regardless of further analysis. Rather this 
provision is intended to ensure that WQS are not only restored when 
found to be impaired, but are in fact maintained when found to be 
attained, consistent with the goals of the Clean Water Act. Higher 
levels of TN and/or TP may be allowed in such watersheds where it is 
demonstrated that such higher levels will fully protect the lake's WQS.
    Where sufficient information is not available to derive TN and/or 
TP DPVs using BATHTUB or another scientifically defensible technical 
model and the lake does not attain the applicable TN, TP, and/or 
chlorophyll a criteria or is un-assessed, lake criteria values for TN 
and/or TP are to be used as the DPVs. EPA believes that this approach 
is protective because the TN and TP concentrations entering the lake 
are unlikely to need to be lower than the criterion concentration 
necessary to be protective of the lake itself.
(g) Stressor-Response Approach
    In deriving the final criteria for lakes, EPA has relied on a 
stressor-response approach which has been well documented and developed 
in a number of different contexts.141 142 143 Stressor-
response approaches estimate the relationship between nitrogen/
phosphorus concentrations and a response measure that is either 
directly or indirectly related to the designated use (in this case, 
chlorophyll a as a measure of attaining a balanced natural population 
of aquatic flora and fauna). Then, concentrations that support the

[[Page 75784]]

designated use can be derived from the estimated relationship. In the 
case of Florida, the use of this approach is supported by a substantial 
Florida-specific database of high quality information, sound scientific 
analysis and technical evaluation.
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    \141\ USEPA. 2000a. Nutrient Criteria Technical Guidance Manual: 
Lakes and Reservoirs. EPA-822-B-00-001. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC.
    \142\ USEPA. 2000b. Nutrient Criteria Technical Guidance Manual: 
Rivers and Streams. EPA-822-B-00-002. U.S. Environmental Protection 
Agency, Office of Water, Washington, DC.
    \143\ USEPA. 2008. Nutrient Criteria Technical Guidance Manual: 
Wetlands. EPA-822-B-08-001. U.S. Environmental Protection Agency, 
Office of Water, Washington, DC.
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    The effects of nitrogen/phosphorus pollution are manifested in 
lakes in a variety of ways and are well-
documented.144 145 146 147 A common effect of nitrogen/
phosphorus pollution in lakes is the over-stimulation of algal growth 
resulting in algal blooms, which can cause changes in algal and animal 
assemblages due to adverse changes in important water quality 
parameters necessary to support aquatic life. Algal blooms can decrease 
water clarity and aesthetics, which in turn can affect the suitability 
of a lake for primary (e.g., swimming) and secondary (e.g., boating) 
contact recreation. Algal blooms can adversely affect drinking water 
supplies by releasing toxins, interfering with disinfection processes, 
or requiring additional treatment. Algal blooms can adversely affect 
biological process by decreasing light availability to submerged 
aquatic vegetation (which serves as habitat for aquatic life), 
degrading food quality and quantity for other aquatic life, and 
increasing the rate of oxygen consumption.
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    \144\ Lee, G.F., W. Rast, R.A. Jones. 1978. Eutrophication of 
water bodies: Insights for an age-old problem. Environmental Science 
and Technology 12: 900-908.
    \145\ Carlson R.E. 1977. A trophic state index for lakes. 
Limnology and Oceanography 22:361-369.
    \146\ Smith, V.H., G.D. Tilman, and J.C. Nekola. 1999. 
Eutrophication: impacts of excess nutrient inputs on freshwater, 
marine, and terrestrial ecosystems. Environmental Pollution 100: 
179-196.
    \147\ Smith, V.H., S.B. Joye, and R.W. Howarth. 2006. 
Eutrophication of freshwater and marine ecosystems. Limnology and 
Oceanography 51:351-355.
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D. Numeric Criterion for the State of Florida's Springs

(1) Final Rule
    EPA defines ``spring'' as a site at which ground water flows 
through a natural opening in the ground onto the land surface or into a 
body of surface water. This definition is drawn from the U.S. 
Geological Survey, Circular 1137.\148\ This definition is not intended 
to include streams that flow in a defined channel that have some 
groundwater baseflow component. EPA recognized that groundwater-surface 
water interactions in Florida are complex and that FDEP will need to 
make site-specific determinations about whether water is subject to the 
stream criteria or the springs criterion. EPA is promulgating the 
numeric criterion for nitrate+nitrite for Florida's springs classified 
as Class I or III waters under Florida law (Section 62-302.400, 
F.A.C.):
---------------------------------------------------------------------------

    \148\ Schiffer, Donna M. 1998. Hydrology of Central Florida 
Lakes--A Primer. U.S. Geological Survey in cooperation with SJWMD 
and SFWMD: Circular 1137.

The applicable nitrate (NO3-) + Nitrite 
(NO2-) is 0.35 mg/L as an annual geometric mean, 
not to be exceeded more than once in a three-year period
(2) Background and Analysis
(a) Derivation of Nitrate + Nitrite Criterion
    In its January proposal, EPA proposed a nitrate+nitrite criterion 
of 0.35 mg/L for springs and clear streams that would support balanced 
natural populations of aquatic flora and fauna in springs. EPA proposed 
criteria for nitrate+nitrite because one of most significant factors 
causing adverse changes in spring ecosystems is the pollution of 
groundwater, principally with nitrate+nitrite, resulting from human 
land use changes, cultural practices, and significant population 
growth.149 150
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    \149\ Katz, B.G., H.D. Hornsby, J.F. Bohlke and M.F. Mokray. 
1999. Sources and chronology of nitrate contamination in spring 
water, Suwannee River Basin, Florida. Water-Resources Investigations 
Report 99-4252. U.S. Geological Survey, Tallahassee, FL. Available 
electronically at: http://fl.water.usgs.gov/PDF_files/wri99_4252_katz.pdf.
    \150\ Brown M.T., K. Chinners Reiss, M.J. Cohen, J.M. Evans, 
P.W. Inglett, K. Sharma Inglett, K. Ramesh Reddy, T.K. Fraze, C.A. 
Jacoby, E.J. Phlips, R.L. Knight, S.K. Notestein, R.G. Hamann, and 
K.A. McKee. 2008. Summary and Synthesis of the Available Literature 
on the Effects of Nutrients on Spring Organisms and Systems. 
University of Florida, Gainesville, Florida. Available 
electronically at: http://www.dep.state.fl.us/springs/reports/files/UF_SpringsNutrients_Report.pdf. Accessed October 2010.
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    EPA based its proposed criterion on multiple lines of stressor-
response evidence, which included controlled, laboratory-scale 
experimental data and analysis of field-based data. EPA's first line of 
evidence is stressor-response data from controlled laboratory 
experiments, which studied the growth response of algae in springs to 
different concentrations of nitrate+nitrite. EPA found in its review of 
comprehensive surveys 151 152 and a study \153\ of 29 
Florida springs at over 150 sampling sites, conducted on behalf of FDEP 
over three years, that two nuisance algal taxa, the cyanobacterium 
Lyngbya wollei and the macroalgae Vaucheria sp., were the most commonly 
occurring taxa. The authors of the study conducted controlled 
laboratory experiments, which tested the growth response of Lyngbya 
wollei and Vaucheria sp. to different doses of nitrate+nitrite. They 
found that Lyngbya wollei and Vaucheria sp. growth rates increased in 
response to increased doses of nitrate+nitrite and that most of their 
highest growth rates were reached at and above 0.23 mg/L 
nitrate+nitrite. EPA interpreted the results from these studies as 
strong empirical evidence of a stressor-response relationship between 
nuisance algae and nitrate+nitrite and further indicated specific 
concentrations above which undesirable growth of nuisance algal may be 
likely to occur.
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    \151\ Pinowska, A., R.J. Stevenson, J.O. Sickman, A. Albertin, 
and M. Anderson. 2007a. Integrated interpretation of survey for 
determining nutrient thresholds for macroalgae in Florida Springs: 
Macroalgal relationships to water, sediment and macroalgae 
nutrients, diatom indicators and land use. Florida Department of 
Environmental Protection, Tallahassee, FL.
    \152\ Stevenson, R.J., A. Pinowska, and Y.K. Wang. 2004. 
Ecological Condition of Algae and Nutrients in Florida Springs. 
Florida Department of Environmental Protection, Tallahassee, FL.
    \153\ Pinowska, A., R.J. Stevenson, J.O. Sickman, A. Albertin, 
and M. Anderson. 2007b. Integrated interpretation of survey and 
experimental approaches for determining nutrient thresholds for 
macroalgae in Florida Springs: Laboratory experiments and 
disturbance study. Florida Department of Environmental Protection, 
Tallahassee, FL.
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    In addition to the laboratory-based experimental evidence, EPA 
reviewed information compiled by FDEP in its assessment of limits to 
restore springs and protect them from excess algal 
growth.154 155 The second line of evidence was based on data 
collected from in-situ algal monitoring and long-term field surveys in 
rivers FDEP considered to exhibit similar aquatic conditions to springs 
(e.g., algal communities, water clarity, and proportion of flow coming 
from a spring). EPA found additional stressor-response evidence in an 
analysis \156\ based on over 200 algal samples collected from 13 
different algal monitoring stations along the Suwannee, Santa Fe, and 
Withlacoochee Rivers from 1990 to 1998. The analysis examined algal 
growth response over a range of nitrate+nitrite concentration. Results 
indicated a sharp increase in

[[Page 75785]]

algal abundance and biomass above 0.4 mg/L nitrate + nitrite.
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    \154\ Gao, X. 2008. Nutrient TMDLs for the Wekiva River (WBIDs 
2956, 2956A, and 2956C) and Rock Springs Run (WBID 2967). Florida 
Department of Environmental Protection, Division of Water Resource 
Management, Tallahassee, FL.
    \155\ Hallas, J.F. and W. Magley. 2008. Nutrient and Dissolved 
Oxygen TMDL for the Suwannee River, Santa Fe River, Manatee Springs 
(3422R), Fanning Springs (3422S), Branford Spring (3422J), Ruth 
Spring (3422L), Troy Spring (3422T), Royal Spring (3422U), and 
Falmouth Spring (3422Z). Florida Department of Environmental 
Protection, Bureau of Watershed Management, Tallahassee, FL.
    \156\ Niu, X.-F. 2007. Appendix B. Change Point Analysis of the 
Suwannee River Algal Data. In Gao, X. 2008. Nutrient TMDLs for the 
Wekiva River (WBIDs 2956, 2956A, and 2956C) and Rock Springs Run 
(WBID 2967). Florida Department of Environmental Protection, 
Division of Water Resource Management, Tallahassee, FL.
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    EPA concluded the two different lines of stressor-response evidence 
point to a nitrate+nitrite concentration of 0.35 mg/L that would 
prevent excess algal growth and be supportive of balanced natural 
populations of aquatic flora and fauna in Florida springs. This 
concentration is higher than that observed in laboratory-scale 
experiments that may not be closely representative of reference spring 
sites in Florida, but lower than the concentration that was associated 
with changes in the balance of natural populations of aquatic flora and 
fauna observed in an analysis of field data. EPA believes a 
nitrate+nitrite criterion set at 0.35 mg/L represents an appropriate 
and reasonable balance of the scientific evidence.
    EPA received a number of comments regarding EPA's proposed 
criterion for springs, including concerns that the biological responses 
observed in the field were not representative of all springs in 
Florida. EPA disagrees with these commenters who suggested that the 
observed effects in the field are not sufficient evidence to support 
numeric criteria derivation in springs. The algal taxa, Lyngbya sp. and 
Vaucheria sp., are representative taxa found in Florida springs. In 
fact, Lyngbya and Vaucheria are the most commonly observed macroalgae 
in Florida springs.\157\ Thus, the Agency considers the biological 
responses of these representative taxa observed in the field and in 
laboratory experiments to be ecologically meaningful and indicative of 
an adverse biological response to elevated nitrate+nitrite 
concentrations above 0.35 mg/L.
---------------------------------------------------------------------------

    \157\ Stevenson, R.J., A. Pinowska, and Y.K. Wang. 2004. 
Ecological Condition of Algae and Nutrients in Florida Springs. 
Florida Department of Environmental Protection, Tallahassee, FL.
---------------------------------------------------------------------------

    EPA also received comment that the proposed nitrate+nitrite 
criterion was inappropriately applied to all clear streams within the 
State. After considering these comments, EPA concluded that clear 
streams are more appropriately addressed as part of the regionalized 
reference approach that is supported by a broader range of stream 
monitoring data as discussed above. Therefore, EPA has decided not to 
finalize the springs nitrate+nitrite criterion in clear streams because 
EPA considers the numeric criteria it is finalizing in this rule for 
streams in the five NWRs, which includes clear streams, to be 
adequately protective and scientifically defensible. These systems will 
also be protected from excess nitrogen from groundwater by the 
nitrate+nitrite criteria applicable in the springs that flow into them; 
thus, additional nitrate+nitrite criteria are not needed.
    In this final rule, EPA is finalizing nitrate+nitrite criterion for 
springs with a magnitude of 0.35 mg/L. For more information regarding 
the springs criterion, please refer to EPA's Final Rule TSD for 
Florida's Inland Waters, Chapter 3: Methodology for Deriving U.S. EPA's 
Criteria for Springs located in the record for this final rule.
(b) Duration and Frequency
    EPA proposed a nitrate+nitrite criterion duration as an annual 
geometric mean with a criterion frequency of not to be exceeded more 
than once in three years. EPA also took comment on alternative 
durations, such as a monthly geometric mean, and alternative 
frequencies, such as a not to be exceeded more than 10% of the time. 
EPA considered that the timescales of the algal responses in the 
laboratory experiments (i.e., 21 to 28 days) might support a shorter 
duration over which biological response to nitrate+nitrite could occur. 
However, EPA found in its review of springs data and information that 
nitrate concentrations can be variable from month to month, and this 
intra-annual variability was not necessarily associated with impairment 
of the designated use. Therefore, to account for intra-annual 
variability, EPA chose to express the nitrate+nitrite criterion for 
springs on an annual basis. Comments included a suggestion to express 
the frequency component of the criterion as ``not to be exceeded during 
a three year period as a three year average.'' However, EPA is 
concerned that cumulative effects of exposure may manifest themselves 
in shorter periods of time than three years. This is because springs 
tend to be clear which provides the opportunity for fast growing 
nuisance algal species to quickly utilize the excess nitrogen. When 
nuisance algae species grow prolifically, they outcompete and replace 
native submerged aquatic vegetation. Thus, more frequent exceedances of 
the criterion-magnitude will not support a balanced natural population 
of aquatic flora and fauna in springs because submerged aquatic 
vegetation can be lost quickly from the effects of nitrate+nitrite 
pollution, but can take many years, if not decades, to recover.\158\ 
For these reasons, EPA is finalizing the proposed duration and 
frequency of an annual geometric mean not to be exceeded more than once 
in three years.
---------------------------------------------------------------------------

    \158\ Duarte, C.M. 1995. Submerged aquatic vegetation in 
relation to different nutrient regimes. Ophelia: International 
Journal of Marine Biology 41: 87-112.
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E. Applicability of Criteria When Final

(1) Final Rule
    This final rule is effective 15 months after publication in the 
Federal Register, except for the Federal site-specific alternative 
criteria (SSAC) provision of section 131.43(e), which is effective 60 
days after publication in the Federal Register. This rule will apply in 
addition to any other existing CWA-effective criteria for Class I or 
Class III waters already adopted and submitted to EPA by the State (and 
for those adopted and submitted to EPA after May 30, 2000, approved by 
EPA). FDEP establishes its designated uses through a system of classes 
and Florida waters are designated into one of several different 
classes. Class III waters provide for healthy aquatic life and safe 
recreational use. Class I waters include all the protection of 
designated uses provided for Class III waters, and also include 
protection for designated uses related to drinking water supply. See 
Section 62-302.400, F.A.C. Class I and III waters, together with Class 
II waters that are designated for shellfish propagation or harvesting, 
comprise the set of Florida waters that are assigned designated uses 
that include the goals articulated in Section 101(a)(2) of the CWA 
(i.e. protection and propagation of fish, shellfish, and wildlife and 
recreation in and on the water).\159\ Class II waters will be covered 
under EPA's forthcoming rulemaking efforts for estuarine and coastal 
waters. EPA is promulgating numeric criteria for lakes and flowing 
waters, consistent with the terms of the Agency's Consent Decree, that 
Florida has designated as Class I or Class III.
---------------------------------------------------------------------------

    \159\ Because FL classifications are cumulative, Class I waters 
include protections for aquatic life and recreation, in addition to 
protecting drinking water supply use.
---------------------------------------------------------------------------

    In terms of final rule language, EPA has removed regulatory 
provisions at 40 CFR 131.43(c)(2)(iii) and 131.43(c)(4)-(6) because 
these criteria (criteria for protection of downstream estuarine waters, 
flowing waters in the South Florida Region, and estuaries and coastal 
waters) will be included with the Agency's 2011 proposed rulemaking for 
estuarine and coastal waters. For water bodies designated as Class I 
and Class III predominately fresh waters, EPA's final numeric criteria 
will be applicable CWA water quality criteria for purposes of 
implementing CWA programs, including permitting under the NPDES 
program, as well as

[[Page 75786]]

monitoring, assessments, and listing of impaired waters based on 
applicable CWA WQS and establishment of TMDLs.
    In this final rule, the Agency has also deleted proposed regulatory 
provisions at 40 CFR 131.43(d)(2)(i)-(iii) on mixing zones, design 
flow, and listing impaired waters. EPA notes that the final criteria in 
this rule are subject to Florida's general rules of applicability in 
the same way and to the same extent as are other State-adopted and/or 
Federally-promulgated criteria for Florida waters. (See 40 CFR 
131.43(d)(2)). States have discretion to adopt policies generally 
affecting the application and implementation of WQS. (See 40 CFR 
131.13). There are many applications of criteria in Florida's water 
quality programs. Therefore, EPA believes that it is not necessary for 
purposes of this final rule to enumerate each of them, nor is it 
necessary to restate any otherwise applicable requirements. This broad 
reference to general rules of applicability provides sufficient 
coverage and has been used without further elaboration in EPA's most 
recent criteria promulgation applicable to State waters.\160\ The 
Agency is also concerned that addressing some applications in this 
final regulations and not others may create unnecessary and unintended 
questions, confusion, and uncertainty about the overall application of 
Florida's general rules.
---------------------------------------------------------------------------

    \160\ See 40 CFR 131.41(d)(2).
---------------------------------------------------------------------------

(2) Summary of Major Comments
    Regarding application of criteria, several commenters asked EPA to 
provide more detail on how waters would be monitored, whether EPA would 
use the rotating basin approach that FDEP uses, how EPA would enforce 
the criteria, and how specific entities would be affected. In response, 
EPA points out that WQS generally, and EPA's rule specifically, do not 
specify how to achieve those WQS. As discussed above, the State of 
Florida will determine how best to meet these Federal numeric criteria 
in a way that most effectively meets the needs of its citizens and 
environment. FDEP is the primary agency responsible for implementing 
CWA programs in the State of Florida. As such, EPA defers to FDEP in 
administering applicable CWA programs consistent with the CWA and EPA's 
implementing regulations. EPA has worked closely with the State to 
address nitrogen/phosphorus pollution problems in Florida. EPA will 
continue to collaborate with FDEP as the State implements EPA's 
Federally-promulgated numeric criteria.
    Several commenters asserted that Florida would not be able to 
implement EPA's Federally-promulgated numeric criteria without first 
adopting the criteria into State law. EPA does not believe that, in 
order to implement EPA's Federally-promulgated numeric criteria, FDEP 
is required to adopt EPA's rule into State law. EPA's numeric criteria 
for Florida's lakes and flowing waters will be effective for CWA 
purposes 15 months after publication of the final criteria in the 
Federal Register and will apply in addition to any other existing CWA-
effective criteria for Class I or Class III waters already adopted by 
the State and submitted to EPA (and for those adopted after May 30, 
2000, adopted and submitted by FDEP and approved by EPA). FDEP retains 
the authority to move forward with its own rulemaking process at any 
time to establish State numeric criteria and to submit such criteria to 
EPA for review and approval under section 303(c) of the CWA. If FDEP 
does not adopt State numeric criteria, the Department retains its 
current authority to implement Federally promulgated criteria through 
the State's narrative or ``free from'' criteria. FDEP's General Counsel 
has confirmed, in a 2005 letter to EPA that the State's water quality 
criteria regulations for surface waters, set out at Section 62-302.500, 
F.A.C., provide authority for the Department to address and implement 
EPA promulgated criteria in CWA programs.\161\
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    \161\ FDEP. 2005, January 5. ``Petition to Withdraw Florida's 
NPDES Authority of March 19, 2004 Response to EPA Letter of December 
8, 2004.'' Letter from George Munson, General Counsel.
---------------------------------------------------------------------------

    Several commenters suggested that EPA incorporate water quality 
targets from adopted and approved TMDLs as site-specific criteria 
(SSAC) for specific waters in lieu of the more broadly applicable 
criteria promulgated by EPA. These commenters asserted that the TMDL 
values better reflect site-specific needs and were already serving as 
the basis for many pollutant reduction actions, including Basin 
Management Action Plans (BMAPs). Commenters expressed concern that 
actions to implement the TMDLs would be curtailed or delayed because of 
the uncertainty whether additional reductions might be required, and 
that both the Federal SSAC process (described in Section V.C of this 
notice) and use attainability analysis (UAA)/variance process would be 
too burdensome and time-consuming to be effective alternatives. 
Similarly, some commenters requested that specific restoration projects 
be exempted from EPA's criteria or that EPA employ a process for 
delaying application of the criteria where a water is under study.
    EPA's position is that EPA-established or approved TMDLs may 
provide sufficient information to support a site-specific alternative 
criterion, but that such a demonstration should be made after 
considering and taking into account any new relevant information 
available, including but not limited to the substantial analysis and 
data considered and made a part of the record for this final rule. For 
this reason, EPA considers the Federal SSAC procedure to be the 
appropriate mechanism for determining whether any specific TMDL target 
should be adopted as a SSAC. For restoration projects or waters under 
study, a State-issued variance may also be an appropriate vehicle for 
regulatory flexibility.
    Several commenters requested clarification regarding the effect of 
EPA's Federally-promulgated numeric criteria on existing TMDLs. A TMDL 
is established at levels necessary to attain and maintain ``applicable 
narrative and numerical water quality standards.'' (See 40 CFR 
130.7(c)(1)). A TMDL addressing a narrative WQS requires translating 
the narrative WQC into a numeric water quality target (e.g., a 
concentration). TMDLs are not implemented directly but through other 
programs such as NPDES permitting and non-point source programs. For 
example, a NPDES permitting authority must ensure at the time of permit 
issuance that WQBELs are consistent with the assumptions and 
requirements of any available wasteload allocation (WLA) for that 
discharge contained in a TMDL, as well as derive from and comply with 
all applicable WQS. (See 40 CFR 122.44(d)(1)(vii)(A) and (B)).
    Some existing TMDLs translate the same portion of Florida's 
narrative criterion, Subsection 62-302.530(47)(b), F.A.C., as EPA has 
translated to derive its numeric criteria, e.g. no imbalance in natural 
populations of aquatic flora and fauna. The permitting authority must 
ensure that any permit issuance or re-issuance include WQBELs that are 
as stringent as necessary to meet the promulgated numeric criteria, 
pursuant to CWA section 301(b)(1)(C) and 40 CFR 122.44(d)(1). These 
existing TMDLs will likely include information that is relevant and 
helpful in evaluating necessary discharge limitations, such as 
consideration of other sources of the pollutant and hydrodynamics of 
the waterbody. EPA recommends that existing TMDLs that are based on 
translation of Subsection 62-302.520(47)(b), F.A.C. (``no imbalance in 
natural population of aquatic flora and

[[Page 75787]]

fauna''), undergo a two-part evaluation. The first step is to assess 
whether the waterbody is still, in fact, water quality-limited 
(impaired) using the new numeric WQC. If the waterbody is still water 
quality-limited, then a second evaluation should be conducted to 
determine whether the existing TMDL based on the narrative is 
sufficient to meet the new numeric criterion, and in turn, whether or 
not it may be appropriate to revise the TMDL. The State may also wish 
to pursue submitting the TMDL water quality target derived by 
translating the narrative for determination as a Federal SSAC.
    Other existing TMDLs translate another part of Florida's narrative 
nutrient criterion, Subsection 62-302.530(47)(a) F.A.C. This provision 
provides that nitrogen/phosphorus pollution shall be limited so as to 
prevent violation of another Florida WQS. Where a TMDL water quality 
target was developed as a translation of this part of Florida's 
narrative nutrient criterion (for example, that amount of nitrogen/
phosphorus that would not cause excursions of Florida's dissolved 
oxygen WQS), the appropriate WQBEL is the more stringent result of 
applying the TMDL WLA or the promulgated numeric criteria.
    It is important to keep in mind that no TMDL will be rescinded or 
invalidated as a result of this final rule, nor does this final rule 
have the effect of withdrawing any prior EPA approval of a TMDL in 
Florida. Neither the CWA nor EPA regulations require TMDLs to be 
completed or revised within any specific time period after a change in 
water quality standards occurs. TMDLs are typically reviewed as part of 
States' ongoing water quality assessment programs. Florida may review 
TMDLs at its discretion based on the State's priorities, resources, and 
most recent assessments. NPDES permits are subject to five-year permit 
cycles, and in certain circumstances are administratively continued 
beyond five years. In practice, States often prioritize their 
administrative workload in permits. This prioritization could be 
coordinated with TMDL review.
    EPA-established or approved TMDLs may provide sufficient 
information to support a site-specific alternative criterion (SSAC). 
The SSAC path is one that local governments or businesses may want to 
pursue where they desire assurance that the TMDL will become the 
applicable numeric criteria in advance of the State's review of the 
TMDL or where substantial investments in pollution controls are 
predicated on water quality based effluent limits, and local 
governments or businesses need long-term planning certainty before 
making these investments. The demonstrations supporting SSAC requests 
for TMDLs should reflect any new relevant information that has become 
available since the TMDL was developed, including but not limited to 
the substantial analysis and data considered and made a part of the 
record for this final rule. For this reason, EPA considers the Federal 
SSAC procedure to be the appropriate mechanism for determining whether 
any specific TMDL target should replace the otherwise applicable 
numeric criteria in this final rule. EPA will work cooperatively with 
entities requesting SSAC to expedite consideration of TMDL targets and 
associated TN and/or TP levels as Federal SSAC for purposes of this 
final rule. As explained in the preamble to the final rule, EPA has 
delayed the effective date of its numeric criteria for 15 months. EPA 
encourages any entity wishing to have EPA adopt a particular TMDL 
target as a SSAC to submit such TMDL to EPA for consideration as a SSAC 
as soon as possible during these 15 months. When submitting such 
requests to EPA, such entity must copy FDEP so that FDEP may provide 
any comments it has to EPA. EPA would then review the SSAC application 
and prepare the SSAC for public notice once this final rule takes 
effect. Following this process, the TMDL target, if scientifically and 
technically justified, could replace the otherwise applicable numeric 
criteria within a very short period of time after this final rule takes 
effect. Following any such establishment of site-specific numeric 
criteria, the State of Florida may review and/or revise the TMDL at its 
discretion based on the changed criteria and the State's priorities, 
resources, and most recent assessments. EPA is still required to 
approve any changes to a previously approved TMDL.
    EPA is extending the effective date of this rule, with the 
exception of the site-specific alternative criteria provision for 
reasons discussed below, for 15 months to allow time for the Agency to 
work with stakeholders and FDEP on important implementation issues and 
to help the public and all affected parties better understand the final 
criteria and the bases for those criteria. EPA solicited comment on the 
rule's proposed effective date in the preamble to the proposed rule (75 
FR 4216 (January 26, 2010)) and received many comments requesting that 
EPA delay the effective date of the final criteria. A range of 
commenters suggested delayed effective dates from several months to 
several years, including linking the effective date of this rule with 
the forthcoming estuaries and coastal waters rule to allow closer 
coordination of the related parts of the two rulemakings. EPA does not 
agree with some commenters that such an extensive delay is necessary. 
However, EPA does believe, as discussed below, that these criteria 
present a unique opportunity for substantial nitrogen and phosphorus 
loadings reductions in the State that would be greatly facilitated and 
expedited by strongly coordinated and well-informed stakeholder 
engagement, planning, and support before a rule of this significance 
and broad scope begins to take effect and be implemented through the 
State's regulatory programs.
    EPA believes that it is critical, before the rule becomes 
effective, to engage and support, in full partnership with FDEP, the 
general public, stakeholders, local governments, and sectors of the 
regulated community across the State in a process of public outreach, 
education, discussion, and constructive planning. EPA solicited comment 
on the proposed rule in January 2010 and has carefully considered those 
comments, which numbered more than 22,000, in developing the final 
rule. However, the nature of rule development has kept EPA from 
publicly discussing the contents of the final rule until the rule 
development process, itself, was complete. An investment in outreach, 
information, coordination, technical assistance and planning following 
this action may result in far more effective, expeditious, and 
ultimately effective implementation of appropriate and badly needed 
nutrient pollution reduction measures leading to public health and 
environmental improvements, the goals of this rule. EPA recognizes that 
in order for FDEP to effectively implement the final criteria for 
nutrients, it needs to plan how to best address the criteria in State 
programs such as the permits, waterbody assessment and listing, and 
TMDL programs. The State may need to develop implementation plans and 
guidance for affected State regulatory programs, train employees, and 
educate the public and regulated communities. EPA will work with FDEP 
as a partner over the next 15 months as FDEP takes the steps necessary 
to implement the new standards in an orderly manner. Moreover, EPA 
believes it would be useful and beneficial to have discussions with 
State and local officials, organizations of interested parties, and 
with the general public to explain the final rule, the bases for that

[[Page 75788]]

rule, and respond to implementation questions and concerns.
    Several stakeholder groups have provided comments about particular 
implementation issues that will require time to address before 
effective implementation of the final rule can be achieved. Florida has 
a unique local government administration structure that includes 
county, municipal, and special districts, all which have overlapping 
authorities with respect to managing water resources. The special 
districts provide water resource management oversight of flood control 
and water supply services. These multiple layers of government 
authorities will require time to coordinate responsibilities. An 
additional concern for local governments is their budgeting process. 
Most local governments operate on a fiscal year cycle of October to 
September; thus they have recently begun a new fiscal year. These local 
governments engage in multi-year budget planning and have already begun 
laying the budget foundations for up to five successive years. EPA 
recognizes that Florida's agricultural community has implemented a 
variety of best management practices (BMPs) that are effective at 
reducing nitrogen and phosphorus pollution from farms. However, 
Florida's agriculture industry is composed of a large number of small 
farms (about 17,000) that have average annual sales of less than 
$10,000 each, and most do not receive any form of government 
assistance.\162\ EPA anticipates that the Natural Resource Conservation 
Service and the University of Florida/Institute of Food and 
Agricultural Sciences Extension will need time to educate those not 
currently enrolled in nutrient management and BMP programs to control 
nutrient runoff.
---------------------------------------------------------------------------

    \162\ NASS. 2009a. 2007 Census of agriculture Florida State and 
county data, Volume 1, Geographic Area Series, Part 9, AC-07-A-9, 
Updated December 2009, National Agricultural Statistics Service, 
U.S. Department of Agriculture, Washington, DC. http://www.agcensus.usda.gov/Publications/2007/Full_Report/Volume_1,_Chapter_1_State_Level/Florida/flv1.pdf (retrieved July 15, 2010).
    NASS. 2009. 2009 State agriculture overview--Florida. U.S. 
Department of Agriculture, National Agricultural Statistics Service, 
Washington, DC, http://www.nass.usda.gov/Statistics_by_State/Ag_Overview/AgOverview_FL.pdf (retrieved June 17, 2010).
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    A delayed effective date of 15 months for the criteria will also 
provide time for interested parties to pursue site-specific alternative 
criteria (SSAC) for a given waterbody. EPA's final rule and associated 
preamble describe the process by which any entity may seek a SSAC. A 
decision to seek a SSAC could not be made, however, until interested 
parties know what the applicable criteria would be. The Federal SSAC 
portion of the rule, Sec.  131.43(e), goes into effect 60 days after 
publication of this rule to allow this important work to proceed in 
advance of the effective date for the remaining provisions of the rule. 
During the 15 months before the criteria become effective, parties may 
evaluate the final criteria, decide whether they want to seek a SSAC, 
and, if so, submit their SSAC application materials to EPA, copying 
FDEP. EPA could then review the application, and if complete, public 
notice the application and technical support document pursuant to the 
SSAC provision in the final rule. If, after reviewing public comment, 
EPA believes that the SSAC application meets the requirements of this 
rule, EPA could determine that such SSAC apply to the specific 
waterbody in lieu of the criteria in the final rule, even before the 
criteria in the final rule become effective due to the earlier 
effective date of the SSAC provision.
    EPA believes that the 15-month period of time between publication 
in the Federal Register and the effective date of the criteria will 
ultimately result in attainment of the criteria in an overall shorter 
period of time. As EPA frequently points out in its guidance and 
training materials, criteria are not ``self-implementing'', that is, it 
takes knowledgeable and experienced professionals to effectively and 
properly employ the criteria in monitoring and assessment programs, 
permit limit derivation and expression, nonpoint source (NPS) control 
strategies, and other program applications. Without time to develop 
procedures, there is the risk of ineffective implementation that will 
not meet the underlying objective of this action--to restore and 
protect Florida's waters from harm caused by nitrogen and phosphorus 
pollution. Well designed and mapped out NPS control strategies, in 
particular, will be critical to gain stakeholder trust and 
participation.
    EPA wishes to actively engage in partnership with FDEP to support 
FDEPs implementation of these new standards, for example by considering 
applications for site-specific alternative criteria. After careful 
consideration of time requirements for critical steps, along with 
recognition of important planning and accounting mechanisms such as 
fiscal years, and local and county meeting and planning cycles, EPA has 
determined that a 15-month time period is both reasonable and will 
allow time for important implementation activities to take place. This 
15-month period will allow for a four-month education and outreach 
rollout to cover the major interest sectors and geographic locations 
throughout the State of Florida; a three-month period of training and 
guidance concurrent with data synthesis and analysis to support 
potential SSAC development; a two-month public comment and response 
period to allow development of effective guidance, training and 
possible workshops to run concurrent with SSAC submittals; a three-
month period for finalizing guidance materials along with development 
of rollout strategies (e.g., for NPS control) concurrent with notice 
and comment of SSAC; and finally a 3-month period for statewide 
education and training on guidance and contingency planning. In short, 
the 15 months before the criteria become effective will ensure 
application of programs to achieve criteria in a manner that makes the 
most efficient use of limited resources and gains the broadest possible 
support for timely and effective action upon reaching the effective 
date of the criteria.

IV. Under what conditions will Federal standards be withdrawn?

    Under the CWA, Congress gave States primary responsibility for 
developing and adopting WQS for their navigable waters. (See CWA 
section 303(a)-(c)). Although EPA is promulgating numeric criteria for 
lakes and springs throughout Florida and flowing waters outside the 
South Florida Region, Florida continues to have the option to adopt and 
submit to EPA numeric criteria for the State's Class I and Class III 
waters consistent with CWA section 303(c) and implementing regulations 
at 40 CFR part 131.
    Pursuant to 40 CFR 131.21(c), EPA's promulgated WQS are applicable 
WQS for purposes of the CWA until EPA withdraws those Federally-
promulgated WQS. Withdrawing the Federal standards for the State of 
Florida would require rulemaking by EPA pursuant to the requirements of 
the Administrative Procedure Act (5 U.S.C.551 et seq.). EPA would 
undertake such a rulemaking to withdraw the Federal criteria if and 
when Florida adopts and EPA approves numeric criteria that fully meet 
the requirements of section 303(c) of the CWA and EPA's implementing 
regulations at 40 CFR part 131.

[[Page 75789]]

V. Alternative Regulatory Approaches and Implementation Mechanisms

A. Designating Uses

(1) Background and Analysis
    Under CWA section 303(c), States shall adopt designated uses after 
taking ``into consideration the use and value of water for public water 
supplies, protection and propagation of fish, shellfish, and wildlife, 
recreation in and on the water, agricultural, industrial and other 
purposes including navigation.'' Designated uses ``shall be such as to 
protect the public health or welfare, enhance the quality of water and 
serve the purposes of [the CWA].'' (See CWA section 303(c)(2)(A)). 
EPA's regulation at 40 CFR 131.3(f) defines ``designated uses'' as 
``those uses specified in water quality standards for each waterbody or 
segment whether or not they are being attained.'' A ``use'' is a 
particular function of, or activity in, waters of the United States 
that requires a specific level of water quality to support it. In other 
words, designated uses are a State's concise statements of its 
management objectives and expectations for each of the individual 
surface waters under its jurisdiction.
    In the context of designating uses, States often work with 
stakeholders to identify a collective goal for their waters that the 
State intends to strive for as it manages water quality. States may 
evaluate the attainability of these goals and expectations to ensure 
they have designated appropriate uses. (See 40 CFR 131.10(g)). 
Consistent with CWA sections 101(a)(2) and 303(c)(2)(A), EPA's 
implementing regulations specify that States adopt designated uses that 
provide water quality for the protection and propagation of fish, 
shellfish, and wildlife and for recreation in and on the water, 
wherever attainable. (See 40 CFR 131.10). Where States do not designate 
those uses, or remove those uses, they must demonstrate that such uses 
are not attainable consistent with the use attainability analysis (UAA) 
provisions of 40 CFR 131.10, specifically 131.10(g). States may 
determine, based on a UAA, that attaining a designated use is not 
feasible and propose to EPA to change the use to something that is 
attainable. This action to change a designated use must be completed in 
accordance with EPA regulations. (See 40 CFR 131.10(g) and (h)). In 
implementing these regulations, EPA allows grouping waters together in 
a watershed in a single UAA, provided that there is site-specific 
information to show how each individual water fits into the group in 
the context of any single UAA and how each individual water meets the 
applicable requirements of 40 CFR 131.10(g).
    EPA's final numeric criteria for lakes and flowing waters apply to 
those waters designated by FDEP as Class I (Potable Water Supplies) or 
Class III (Recreation, Propagation and Maintenance of a Healthy, Well-
Balanced Population of Fish and Wildlife). If Florida removes either 
the Class I and/or Class III designated use for any particular 
waterbody ultimately affected by this rule, and EPA finds that removal 
to be consistent with CWA section 303(c) and regulations at 40 CFR part 
131, then the Federally-promulgated numeric criteria would not apply to 
that waterbody because it would no longer be designated Class I or III. 
Instead, any criteria associated with the newly designated use would 
apply to that waterbody.
(2) Summary of Major Comments
    Many commenters took the opportunity to emphasize the need to 
adhere to the regulations governing the process of modifying or 
removing a designated use. Some commenters suggested that the process 
to change a designated use is extremely difficult. EPA's experience is 
that UAAs may range from simple to complex, depending on a variety of 
factors, such as the type of waterbody involved, the size of the 
segment, the use being changed, the relative degree of change proposed 
for the designated use, the presence of unique ecological habitats, and 
the level of public interest/involvement in the designated use 
decision. EPA agrees that, while a UAA is being conducted, the current 
designated use and corresponding criteria remain in place. In the case 
of Florida's Class I and Class III flowing waters and lakes, EPA's 
promulgated numeric criteria will remain the applicable WQS for CWA 
purposes, including assessments, listings, TMDL development and the 
issuance of NPDES permits, unless and until the State adopts revised 
designated uses (with different associated criteria) that are submitted 
to and approved by EPA under CWA section 303(c).

B. Variances

(1) Final Rule
    For purposes of this rule, EPA is promulgating criteria that apply 
to use designations that Florida has already established. EPA believes 
that the State has sufficient authority to use its currently EPA-
approved variance procedures with respect to a temporary modification 
of its Class I or Class III uses as it pertains to any Federally-
promulgated criteria. For this reason, EPA did not propose and is not 
promulgating an alternative Federal variance procedure.
(2) Background and Analysis
    A variance is a temporary modification to the designated use and 
associated water quality criteria that would otherwise apply to the 
receiving water.\163\ Variances constitute new or revised WQS subject 
to the substantive requirements applicable to removing a designated 
use.\164\ Thus, a variance is based on the same factors, set out at 40 
CFR 131.10(g), that are required to revise a designated use through a 
UAA. Typically, variances are time-limited (e.g., three to five years), 
but renewable. Temporarily modifying the designated use for a 
particular waterbody through a variance process allows a State to limit 
the applicability of a specific criterion to that water and to identify 
an alternative designated use and associated criteria to be met during 
the term of the variance. A variance should be used instead of removal 
of a use where the State believes the standard can be attained at some 
point in the future. By maintaining the designated use for all other 
criteria and dischargers, and by specifying a point in the future when 
the designated use will be fully applicable in all respects, the State 
ensures that further progress will be made in improving water quality 
and attaining the standard. A variance may be written to address a 
specified geographic area, a specified pollutant or pollutants, and/or 
a specified pollutant source. All other applicable WQS not specifically 
modified by the variance would remain applicable (e.g., any other 
criteria adopted to protect the designated use). State variance 
procedures, as part of State WQS, must be consistent with the 
substantive requirements of 40 CFR part 131. Each variance, as a 
revised WQS, must be submitted to EPA for review pursuant to CWA 
section 303(c). A variance allows, among other things, NPDES permits to 
be written such that reasonable progress is made \165\ toward attaining 
the underlying standards for affected waters without violating section 
402(a)(l) of the Act, which requires that NPDES permits

[[Page 75790]]

must meet the applicable WQS. (See CWA section 301(b)(1)(C)).
---------------------------------------------------------------------------

    \163\ Water Quality Standards Regulation, 40 CFR part 131: 
Advance notice of proposed rulemaking. USEPA FR 63:129 (July 7, 
1998). p. 36741-36806.
    \164\ In re Bethlehem Steel Corporation, General Counsel Opinion 
No. 58. March 29, 1977 (1977 WL 28245 (E.P.A. G.C.)).
    \165\ USEPA. 1994. Water Quality Standards Handbook: Second 
Edition. EPA-823-B-94-005a. U.S. Environmental Protection Agency, 
Office of Water, Washington, DC.
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(3) Summary of Major Comments
    In response to comments, EPA agrees that variances could be adopted 
on a multiple-discharger basis and can be renewed so long as the State 
and EPA conclude that such variances are consistent with the CWA and 
implementing regulations. In this regard, EPA allows grouping waters 
together in a watershed in a single variance application, provided that 
there is site-specific information to show how each individual water 
fits into the group in the context of any single variance and how each 
individual water meets the applicable requirements of 40 CFR 131.10(g). 
EPA disagrees that Florida law, at 403.201(2), F.S., prohibits the 
State from issuing variances for waters affected by the Federally-
promulgated numeric criteria. Florida law at 403.201(2), F.S., provides 
that a variance may not be granted that would result in State 
requirements that are less stringent than a comparable Federal 
provision or requirement. As discussed above, a variance is a temporary 
modification to the designated use and thus to the associated water 
quality criteria that would otherwise apply to the receiving water. 
EPA's Federal rule, however, does not promulgate or revise any Florida 
designated uses. EPA's criteria are intended to protect the Class I and 
Class III designated uses that Florida already has in place. EPA's 
criteria do not apply where and when the use is something other than 
Class I or Class III, as would be the case for a variance. Rather, 
Florida would establish alternative criteria associated with the 
variance. Any variance would constitute a new or revised WQS subject to 
EPA review and approval pursuant to section 303(c) of the CWA.

C. Site-Specific Alternative Criteria

(1) Final Rule
    EPA believes that there is benefit in establishing a specific 
procedure in the Federal rule for EPA adoption of Federal site-specific 
alternative criteria (SSAC) for the numeric chlorophyll a, TN, TP, and 
nitrate+nitrite criteria in this rule. In this rulemaking, EPA is 
promulgating a procedure whereby the Regional Administrator, Region 4, 
may establish a SSAC after providing for public comment on the proposed 
SSAC and the supporting documentation. (See 40 CFR 131.43(e)). This 
procedure allows any entity, including the State, to submit a proposed 
Federal SSAC directly to EPA for the Agency's review and assessment as 
to whether an adjustment to the applicable Federal numeric criteria is 
appropriate and warranted. The Federal SSAC process is separate and 
distinct from the State's SSAC processes in its WQS.
    The Federal SSAC procedure allows EPA to determine that a revised 
site-specific chlorophyll a, TN, TP, or nitrate + nitrite numeric 
criterion should apply in lieu of the generally applicable criteria 
promulgated in this final rule where that SSAC is demonstrated to be 
protective of the applicable designated use(s). The promulgated 
procedure provides that EPA will solicit public comment on its 
determination. Because EPA's rule establishes this procedure, 
implementation of this procedure does not require withdrawal of 
Federally-promulgated criteria for affected water bodies for the 
Federal SSAC to be effective for purposes of the CWA. EPA has 
promulgated similar procedures for EPA granting of variances and SSACs 
in other Federally-promulgated WQS.\166\
---------------------------------------------------------------------------

    \166\ See 40 CFR 131.33(a)(3), 40 CFR 131.34(c), 40 CFR 
131.36(c)(3)(iii), 40 CFR 131.38(c)(2)(v), 40 CFR 131.40(c).
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    EPA is aware of concerns expressed by some commenters that a 
waterbody may exceed the numeric criteria in this rule and still meet 
Florida's designated uses related to recreation, public health, and the 
propagation and maintenance of a healthy, well-balanced population of 
fish and wildlife. EPA recognizes that there may be certain situations 
where additional, new, or more specific data related to the local 
conditions or biology of a particular waterbody may well support an 
alternate site-specific numeric criteria which may appropriately be 
more (or less) stringent than the criteria in this final rule in order 
to ensure maintenance of instream designated uses and protection of 
downstream waters. EPA believes that the SSAC process is an appropriate 
mechanism to address such situations and is committed to acting on 
Federal SSAC applications intended to address such situations as 
expeditiously as possible.
    The process for obtaining a Federal SSAC includes the following 
steps. First, an entity seeking a SSAC compiles the supporting data, 
conducts the analyses, develops the expression of the criterion, and 
prepares the supporting documentation demonstrating that alternative 
numeric criteria are protective of the applicable designated use. The 
``entity'' may be the State, a city or county, a municipal or 
industrial discharger, a consulting firm acting on a behalf of a 
client, or any other individual or organization. The entity requesting 
the SSAC bears the burden of demonstrating that any proposed SSAC meets 
the requirements of the CWA and EPA's implementing regulations, 
specifically 40 CFR 131.11. Second, if the entity is not the State, the 
entity must provide notice of the proposed SSAC to the State, including 
all supporting documentation so that the State may provide comments on 
the proposal to EPA. Third, the Regional Administrator will evaluate 
the technical basis and protectiveness of the proposed SSAC and decide 
whether to publish a public notice and take comment on the proposed 
SSAC. The Regional Administrator may decide not to publish a public 
notice and instead return the proposal to the entity submitting the 
proposal, with an explanation as to why the proposed SSAC application 
did not provide sufficient information for EPA to determine whether it 
meets CWA requirements or not. If EPA solicits public comment on a 
proposed SSAC, upon review of comments, the Regional Administrator may 
determine that the Federal SSAC is appropriate to account for site-
specific conditions and make that determination publicly available 
together with an explanation of the basis for the decision. The 
Regional Administrator may also determine that the Federal SSAC is not 
appropriate and make that determination publicly available together 
with an explanation of the basis for the decision.
    To successfully develop a Federal SSAC for a given lake, stream, or 
spring, a thorough analysis is necessary that indicates how designated 
uses are being supported both in the waterbody itself and in downstream 
water bodies at concentrations of either TN, TP, chlorophyll a, or 
nitrate+nitrite that are either higher or lower than the Federally-
promulgated applicable criteria. This analysis should have supporting 
documentation that consists of examining both indicators of longer-term 
response to multiple stressors, such as benthic macroinvertebrate 
health as determined by Florida's Stream Condition Index (SCI), and 
indicators of shorter-term response specific to nitrogen/phosphorus 
pollution, such as periphyton algal thickness or water column 
chlorophyll a concentrations. To pursue a Federal SSAC on a watershed-
wide basis, the same types of procedures that EPA used to develop the 
Federally promulgated applicable criteria can be used with further 
refinements to the categorization of water bodies. For example, an 
entity could derive alternative instream protective TP and/or TN values 
using

[[Page 75791]]

EPA's approach by further sub-delineating the Nutrient Watershed 
Regions and providing the corresponding data, analysis and 
documentation to support derivation of an alternative criteria that is 
protective of the designated use that applies both to the smaller 
watershed regions as well as to downstream waters. This type of refined 
reference condition approach is described in EPA guidance manuals \167\ 
and would be consistent with methods used to develop the Federally-
promulgated criteria for Florida. In developing either a site-specific 
or watershed-wide Federal SSAC, it is necessary to ensure that values 
allowed in an upstream segment as a result of a SSAC provide for the 
attainment and maintenance of the WQS of downstream waters. It will be 
important to examine a stream system on a broader basis to ensure that 
a SSAC established for one segment does not result in adverse effects 
in nearby segments or downstream waters, such as a downstream lake.
---------------------------------------------------------------------------

    \167\ USEPA. 2000b. Nutrient Criteria Technical Guidance Manual: 
Rivers and Streams. EPA-822-B-00-002. U.S. Environmental Protection 
Agency, Office of Water, Washington, DC.
---------------------------------------------------------------------------

    This rule specifically identifies four approaches for developing 
SSAC. The first two approaches are replicating the approaches EPA used 
to develop stream and lake criteria, respectively, and applying these 
methods to a smaller subset of waters. The third approach for 
developing SSAC is to conduct a biological, chemical, and physical 
assessment of waterbody conditions. The fourth approach for developing 
SSAC is a general provision for using another scientifically defensible 
approach that is protective of the designated use. The first two 
approaches for developing SSAC replicate EPA's methods in deriving the 
stream and lake criteria set out in this final rule. To understand the 
necessary steps in this analysis, interested parties should refer to 
the complete documentation of these methods in the materials included 
in the rule docket.
    The third approach for developing SSAC is to conduct a biological, 
chemical, and physical assessment of waterbody conditions. This is a 
more general approach than the replication approaches and would need 
additional detail and description of supporting rationale in the 
documentation submitted to EPA. The components of this approach could 
include, but not be limited to, evaluation of benthic macroinvertebrate 
health using the Stream Condition Index (SCI), presence or absence of 
native flora and fauna, chlorophyll a concentrations or periphyton 
density, average daily dissolved oxygen fluctuation, organic versus 
inorganic components of total nitrogen, habitat assessment, and 
hydrologic disturbance. This approach could apply to any waterbody 
type, with specific components of analysis tailored for the situation. 
The fourth approach for developing SSAC is a general provision for 
using another scientifically defensible approach that is protective of 
the designated use. This provision allows applicants to make a complete 
demonstration to EPA using methods not otherwise described in the rule 
or its statement of basis, consistent with 40 CFR 131.11(b)(1)(iii). 
This approach could potentially include use of mechanistic models or 
other data and information.
 (2) Background and Analysis
    A SSAC is an alternative value to criteria set forth in this final 
rule that would be applied on a watershed, area-wide, or water-body 
specific basis that meets the regulatory test of protecting the 
instream designated use, having a basis in sound science, and ensuring 
the protection and maintenance of downstream WQS. SSAC may be more or 
less stringent than the otherwise applicable Federal numeric criteria. 
In either case, because the SSAC must protect the same designated use 
and must be based on sound science (i.e., meet the requirements of 40 
CFR 131.11(a)), there is no need to modify the designated use or 
conduct a UAA. A SSAC may be appropriate when further scientific data 
and analyses can bring added precision or accuracy to express the 
necessary level or concentration of chlorophyll a, TN, TP, and/or 
nitrate+nitrite that protects the designated use for a particular 
waterbody.
 (3) Summary of Major Comments
    Many commenters expressed support for the concept of EPA's proposed 
SSAC procedure, although many also expressed concerns about the 
viability, requirements, expense, and time associated with the process. 
In EPA's proposed rule, the SSAC process was to be initiated by the 
State submitting a request to EPA. Many commenters were confused about 
the relationship between the Federal SSAC process and the State's Type 
1 and Type 2 SSAC processes, and how the processes relate for purposes 
of the Federal rule. The Federal SSAC process is separate and 
independent from the State SSAC processes. A Federal SSAC is 
established by the Regional Administrator of EPA Region 4 after due 
notice and comment from the public. To resolve this confusion, and to 
provide a more direct means for entities other than the State to 
initiate the SSAC process, EPA's final rule provides that any entity 
may submit a request for a SSAC directly to the Regional Administrator. 
The final rule adds a requirement that entities submit proposed SSAC 
and supporting materials to the State at the same time those materials 
are submitted to EPA to ensure the State has the opportunity to submit 
comments to EPA.
    As several commenters have pointed out, Florida WQS regulations 
currently do not authorize the State to adopt a SSAC as State WQS 
except where natural conditions are outside the limits of broadly 
applicable criteria established by the State (Section 62-302.800, 
F.A.C.). However, the State may choose to be the entity that submits a 
SSAC request to EPA under the Federal process described above and set 
forth at 40 CFR 131.43(e). There is no requirement that the State go 
through its own State-level Type 1 or Type 2 SSAC process before 
submitting a proposed SSAC to EPA for consideration under this rule.
    Commenters included suggestions for specific approaches for 
developing SSAC as well as an ``expedited'' process for determination 
as a Federal SSAC. EPA agrees that many of the suggested approaches 
have merit for purposes of developing SSAC, and has adapted many of the 
suggestions to provide more information on approaches that would meet 
the general requirements for protective criteria. Many of the comments 
regarding an ``expedited'' process suggested a process where SSAC 
become effective automatically, without need for EPA review and 
approval. With the exception of State adjustment of lake criteria 
within a very specific and limited range accompanied by a specified 
data set and calculation as discussed in Section III.C(2)(e) above, the 
Agency does not agree with the view that criteria established in this 
rule can be revised without documentation and public notice and comment 
process as outlined above.\168\ Another commenter asked about the 
potential to develop a SSAC on a ``watershed-scale.'' EPA does not see 
any barrier to conducting such an analysis, where it can be 
demonstrated that the watershed-scale SSAC is protective for all waters 
in a particular grouping and meets the requirements of 40 CFR 131.11 
and 40

[[Page 75792]]

CFR 131.10(b). Many commenters expressed the desire to defer the 
applicability of promulgated criteria prior to developing a SSAC. The 
Federal SSAC portion of the rule, Sec.  131.43(e), goes into effect 60 
days after publication of this rule to allow this important work to 
proceed in advance of the effective date of 15 months after publication 
for the remaining provisions of the rule. The SSAC review process will 
depend in substantial part on the nature of the SSAC proposal itself: 
Its clarity, substance, documentation, and scientific rigor. Some 
commenters stated that EPA's requirement that Federal SSAC be 
scientifically defensible and protective of designated uses is too 
vague; however, it is the same requirement for criteria in the Federal 
WQS regulation. (See 40 CFR 131.11). EPA will consider the need for 
further developing supporting technical guidance in the future if it 
appears at that time that such guidance would help support the process.
---------------------------------------------------------------------------

    \168\ EPA's criteria allow for one-time site-specific 
modifications to the promulgated lake criteria, without requiring 
those modifications to be submitted as SSAC. See 40 CFR 
131.43(c)(1)(ii) and Section III.C(2)(e).
---------------------------------------------------------------------------

D. Compliance Schedules

(1) Final Rule
    Florida has adopted a regulation authorizing compliance schedules. 
That regulation, Subsection 62-620.620(6), F.A.C., is not affected by 
this final rule. The complete text of the Florida rules concerning 
compliance schedules is available at https://www.flrules.org/gateway/RuleNo.asp?ID=62-620.620. Florida is, therefore, authorized to grant 
compliance schedules, as appropriate, under its rule for WQBELs based 
on EPA's numeric criteria.
(2) Background and Analysis
    A compliance schedule, or schedule of compliance, refers to ``a 
schedule of remedial measures included in a `permit,' including an 
enforceable sequence of interim requirements * * * leading to 
compliance with the CWA and regulations.'' (See 40 CFR 122.2, CWA 
section 502(17)). In an NPDES permit, WQBELs are effluent limits based 
on applicable WQS for a given pollutant in a specific receiving water 
(See NPDES Permit Writers Manual, EPA-833-B-96-003, December, 1996). 
EPA regulations provide that schedules of compliance may only be 
included in permits if they are determined to be ``appropriate'' given 
the circumstances of the discharge and are to require compliance ``as 
soon as possible'' (See 40 CFR 122.47).\169\
---------------------------------------------------------------------------

    \169\ Hanlon, Jim, USEPA Office of Wastewater Management. 2007, 
May 10. Memorandum to Alexis Stauss, Director of Water Division EPA 
Region 9, on ``Compliance Schedules for Water Quality-Based Effluent 
Limitations on NPDES Permits.''
---------------------------------------------------------------------------

(3) Summary of Major Comments
    EPA generally received favorable comment on its description of 
compliance schedules. Some commenters asked EPA to consider 
promulgating its own compliance schedule provisions as part of the 
final rule. Florida's regulations, however, already include an 
authorizing provision that allows NPDES permit writers to include 
compliance schedules in permits, where appropriate. Florida's 
regulations do not limit the criteria which may be subject to 
compliance schedules. Therefore, Florida may choose to issue permit 
compliance schedules for nitrogen/phosphorus pollution, as appropriate. 
As a result, there is no need for EPA to provide an additional 
compliance schedule authorizing provision in this final rule. EPA 
disagrees with commenters who assert that Florida's regulation at 
Subsection 62-620.620(6), F.A.C., authorizing compliance schedules 
applies only to industrial and domestic wastewater facilities. Chapter 
62-620, F.A.C., sets out permit procedures for wastewater facilities or 
activities that discharge wastes into waters of the State or which will 
reasonably be expected to be a source of water pollution. (See 
Subsection 62-620.100(1), F.A.C.). Subsection 62-620.620(6), F.A.C., 
applies, therefore, more broadly than to just industrial and domestic 
wastewater facilities. In addition, Chapter 62-4, F.A.C., which sets 
out procedures on how to obtain a permit from FDEP, provides that 
permits may include a reasonable time for compliance with new or 
revised WQS. Subsection 62-4.160(10), F.A.C., does not limit the type 
of permits that may include such compliance schedules.

E. Proposed Restoration Water Quality Standard

(1) Final Rule
    In EPA's January 2010 proposal, the Agency proposed a new WQS 
regulatory tool for Florida, referred to as ``restoration WQS'' for 
impaired waters. This provision was intended to allow Florida to retain 
full aquatic life protection (uses and criteria) for its water bodies 
while establishing a transparent phased WQS process that would result 
in implementation of enforceable measures and requirements to improve 
water quality over a specified time period to ultimately meet the long-
term designated aquatic life use. For reasons discussed below and in 
EPA's response to comment document, EPA has decided not to promulgate a 
restoration WQS tool specifically for Florida, as proposed.
(2) Summary of Major Comments
    EPA received a significant number of comments on its proposal that 
provided constructive and useful information for EPA to consider 
regarding the proposed restoration WQS provision. Such comments ranged 
from identifying additional needed requirements to concerns that the 
restoration WQS tool was so burdensome it would not be helpful. EPA 
evaluated the current, existing flexibility available to Florida to 
implement this final rule through variances, compliance schedules, 
permit reissuance cycles, permit reopener provisions, TMDL scheduling, 
and workload and administrative prioritization. These are all 
considerations that FDEP presently brings to the administration of its 
water quality program. EPA also considered the flexibility that this 
final rule offers through lake criteria adjustment provisions, 
alternative approaches to deriving downstream lake protection values 
and the SSAC process discussed above. The Agency concluded that the 
range of implementation tools available to the State in combination 
with a number of the provisions contained in this final rule provide 
adequate flexibility to implement EPA's numeric criteria finalized in 
this rule. Florida may use any of these existing tools or exercise its 
authority to propose additional tools in the future that allow 
implementation flexibility where demonstrated to be appropriate and 
consistent with the CWA and implementing regulations. Therefore, EPA 
believes that its decision not to finalize restoration WQS will not 
adversely affect Florida's ability to implement the Federal numeric 
criteria.

VI. Economic Analysis

    State implementation of this rule may result in new or revised 
National Pollutant Discharge Elimination System (NPDES) permit 
conditions for point source dischargers, and requirements for nitrogen/
phosphorus pollution treatment controls on other sources (e.g., 
agriculture, urban runoff, and/or septic systems) through the 
development of additional Total Maximum Daily Loads (TMDLs) and Basin 
Management Action Plans (BMAPs). To provide information on the 
potential incremental costs associated with these related State 
actions, EPA conducted an analysis to estimate both the additional 
impaired waters that may be identified as a result of this final rule 
and the potential State of Florida requirements that may be

[[Page 75793]]

necessary to assure attainment of applicable State water quality 
designated uses. EPA's analysis is fully described in the document 
entitled: ``Economic Analysis of Final Water Quality Standards for 
Nutrients for Lakes and Flowing Waters in Florida,'' which can be found 
in the docket and record for this final rule.
    An economic analysis of a regulation compares a likely scenario 
absent the regulation (the baseline) to a likely scenario with the 
regulation. The impacts of the regulation are measured by the resulting 
differences between these two scenarios (incremental impacts). However, 
the regulatory effect of this final rule can be interpreted in several 
ways, which can significantly influence the conditions considered 
appropriate for representing the baseline. On January 14, 2009 EPA made 
a determination that numeric nutrient water quality criteria were 
necessary to meet the requirements of the CWA in the State of Florida. 
In July 2009 the State of Florida released draft numeric nutrient 
criteria for lakes and streams.\170\ Therefore, when the Agency 
proposed this rule for lakes and flowing waters in January 2010, EPA 
evaluated the incremental impacts of the proposed rule in comparison 
with the provisions of the Florida July 2009 draft criteria. Although 
the State subsequently did not proceed forward with those numeric 
criteria provisions, EPA has conducted the same evaluation as part of 
the economic analysis accompanying this final rule to illustrate the 
difference between Florida's draft approach and the provisions of this 
rule. Using this same baseline approach and the refined analysis 
methodology described below, EPA estimates the potential incremental 
costs associated with this rule as ranging between $16.4 million/year 
and $25.3 million/year.
---------------------------------------------------------------------------

    \170\ Florida Department of Environmental Protection, 2009, 
``Draft Technical Support Document: Development of Numeric Nutrient 
Criteria for Florida Lakes and Streams,'' available electronically 
at: http://www.dep.state.fl.us/water/wqssp/nutrients/docs/tsd_nutrient_crit.docx.
---------------------------------------------------------------------------

    An alternative interpretation of the impact of this final rule is 
that EPA is promulgating numeric criteria to address deficiencies in 
the State of Florida's current narrative nutrient criteria (current 
conditions approach), and the incremental impacts of this rule are 
those associated with the difference between EPA's numeric criteria and 
Florida's narrative criteria. Under this scenario, the baseline 
incorporates requirements associated with current water quality, 
impaired waters, and TMDLs that exist at the time of the analysis. The 
incremental impacts of this rule are the costs and benefits associated 
with additional pollution controls beyond those currently in place or 
required as a result of Florida's existing narrative criteria. This 
analysis is principally designed to gain an understanding of the 
potential costs and benefits associated with implementation of EPA's 
numeric criteria for lakes and flowing waters above and beyond the 
costs associated with State implementation of its current narrative 
nutrient criteria for those waters. For waters that the State of 
Florida has already identified as impaired, EPA expects that the effect 
of this final rule will be to shorten the time and reduce the resources 
necessary for the State of Florida to implement its existing regulatory 
and nonregulatory framework of tools, limits, measures and BMP guidance 
to initiate a broader, expedited, more comprehensive, and more 
effective approach to reducing nutrient loadings necessary to meet the 
numeric criteria that support current State designated uses. The 
further effect of this final rule will likely be the assessment and 
identification of additional waters that are impaired and not meeting 
the designated use set forth at Section I.B, and new or revised water 
quality-based effluent limits in NPDES permits. EPA's economic analysis 
quantifies the costs and cost savings associated with the 
identification of newly impaired waters and new or revised water 
quality-based effluent limits, but does not attempt to measure the 
costs and cost savings associated with addressing waters that are 
currently listed as impaired under Florida's existing narrative 
nutrient criteria (these costs are considered part of the baseline).
    Although using the State of Florida's draft numeric criteria as a 
baseline provides one possible measure of the incremental impact 
associated with this final rule, the current conditions approach can 
provide valuable information to the State of Florida and the public 
about other potential costs and benefits that may be realized as a 
result of this final rule. To provide this additional information, and 
in part to respond to public comments on the economic analysis at 
proposal, this economic analysis also measures the incremental costs 
and benefits of this final rule using current conditions in the State 
of Florida as the baseline. Using this interpretation of the baseline, 
EPA estimates the potential incremental costs associated with this 
final rule as ranging between $135.5 million per year and $206.1 
million per year. Although analyses using both baselines are described 
in EPA's economic analysis document entitled: ``Economic Analysis of 
Final Water Quality Standards for Nutrients for Lakes and Flowing 
Waters in Florida,'' the analytical methods and results described below 
highlight the current conditions baseline in detail.
    To develop this analysis, EPA first assessed State control 
requirements associated with current water quality, impaired waters, 
and total maximum daily loads (the baseline). EPA then assessed the 
costs and benefits associated with additional pollution controls beyond 
those currently in place or required to meet EPA's numeric criteria 
that support Florida designated uses. To estimate incremental point 
source costs, EPA gathered publicly available information and data on 
control technologies currently in place at wastewater treatment plants 
and other industrial facilities, and used Florida Department of 
Environmental Protection (FDEP) point source implementation procedures 
to project the potential additional treatment that the State may 
require as a result of applying the criteria in this final rule. EPA 
assessed potential non-point source control costs by using publicly 
available information and data to determine land uses near waters that 
would likely be identified as impaired under this rule, and using FDEP 
and the Florida Department of Agriculture and Consumer Services (FDACS) 
nonpoint source control procedures, estimated costs to implement 
agricultural best management practices (BMPs) the State may require in 
order to attain the new numeric criteria. EPA also estimated the 
potential costs of additional State control requirements for storm 
water runoff, and potential costs associated with upgrades of homeowner 
septic systems. EPA also assessed additional potential government 
regulatory costs of developing additional total maximum daily loads 
(TMDLs) for waters identified as impaired under this rule. Finally, EPA 
qualitatively and quantitatively described and estimated some of the 
potential benefits of complying with the new water quality standards. 
Because of the inherent uncertainties associated with the benefits 
analysis, potential benefits are likely underestimated compared to 
costs. Although it is difficult to predict with certainty how the State 
of Florida will implement these new water quality standards, the 
results of these analyses represent EPA's estimates of costs and 
benefits of this final rule.

A. Point Source Costs

    Point sources of wastewater must have a National Pollution 
Discharge

[[Page 75794]]

Elimination System (NPDES) permit to discharge into surface waters. EPA 
identified point sources potentially discharging nitrogen or phosphorus 
to lakes and flowing waters by evaluating EPA's NPDES Permit Compliance 
System (PCS) database. EPA identified all the industry codes associated 
with any permitted discharger with an existing numeric effluent limit 
or monitoring requirement for nitrogen or phosphorus. This analysis 
identified 193 point sources as having the potential to discharge 
nitrogen and/or phosphorus. The following table summarizes the number 
of point sources with the potential to discharge nitrogen and/or 
phosphorus.

   Table VI(A)--Point-Sources Potentially Discharging Nitrogen and/or Phosphorus to Florida Lakes and Flowing
                                                     Waters
----------------------------------------------------------------------------------------------------------------
                                                                  Major             Minor
                    Discharger category                      dischargers \a\   dischargers \b\        Total
----------------------------------------------------------------------------------------------------------------
Municipal Wastewater......................................                43                42                85
Industrial Wastewater.....................................                57                51               108
                                                           -----------------------------------------------------
    Total.................................................               100                93               193
----------------------------------------------------------------------------------------------------------------
\a\ Facilities discharging greater than one million gallons per day and likely to discharge toxic pollutants in
  toxic amounts.
\b\ Facilities discharging less than one million gallons per day and not likely to discharge toxic pollutants in
  toxic amounts.

1. Municipal Waste Water Treatment Plant (WWTP) Costs
    EPA considered the costs of known nitrogen and phosphorus treatment 
options for municipal WWTPs. Nitrogen and phosphorus removal 
technologies that are available can reliably attain an annual average 
total nitrogen (TN) concentration of approximately 3.0 mg/L or less and 
an annual average total phosphorus (TP) concentration of approximately 
0.1 mg/L or less.\171\ Wastewater treatment to these concentrations was 
considered target levels for the purpose of this analysis.
---------------------------------------------------------------------------

    \171\ U.S. EPA, 2008, ``Municipal Nutrient Removal Technologies 
Reference Document. Volume 1--Technical Report,'' EPA 832-R-08-006.
---------------------------------------------------------------------------

    The NPDES permitting authority determines the need for water 
quality based effluent limits for point sources on the basis of 
analysis of reasonable potential to exceed water quality criteria. To 
estimate the potential incremental costs for WWTPs, the likelihood that 
WWTPs discharging to Florida lakes and flowing waters have reasonable 
potential to exceed the numeric criteria in this final rule should be 
evaluated. However, the site-specific data and information required to 
precisely determine reasonable potential for each facility was not 
available. Thus, on the basis that most WWTPs are likely to discharge 
nitrogen and phosphorus at concentrations above applicable criteria, 
EPA made the conservative assumption that all WWTPs have reasonable 
potential to exceed the numeric criteria.
    For municipal wastewater, EPA estimated costs to reduce effluent 
concentrations to 3 mg/L or less for TN and 0.1 mg/L or less for TP 
using advanced biological nutrient removal (BNR). Although reverse 
osmosis and other treatment technologies may have the potential to 
reduce nitrogen and phosphorus concentrations even further, EPA 
believes that implementation of reverse osmosis applied on such a large 
scale has not been demonstrated as practical or necessary.\172\ Such 
treatment has not been required for WWTPs by the State of Florida in 
the past, even those WWTPs under TMDLs with nutrient targets comparable 
to the criteria in this final rule. EPA believes that should state-of-
the-art BNR technology together with other readily available physical 
and chemical treatment demonstrated to be effective in municipal WWTP 
operations not result in compliance with permit limits associated with 
meeting the new numeric nutrient criteria, then it is reasonable to 
assume that entities would first seek out other available means of 
attaining water quality standards such as reuse, nonpoint source 
reductions, site-specific alternative criteria, variances, and 
designated use modifications.
---------------------------------------------------------------------------

    \172\ Treatment using reverse osmosis also requires substantial 
amounts of energy and creates disposal issues as a result of the 
large volume of concentrate that is generated.
---------------------------------------------------------------------------

    To estimate compliance costs for WWTPs, EPA identified current WWTP 
treatment performance using information obtained from NPDES permits 
and/or water quality monitoring reports. EPA assumed that WWTPs under 
existing TMDLs are currently meeting their wasteload allocation 
requirements and would not incur additional treatment costs. EPA 
further assumed that costs to WWTPs discharging to currently impaired 
waters are not attributable to this final rule because those costs 
would be incurred absent the rule (under the baseline). However, 
sufficient location information was not available to insure that all 
WWTPs discharging to impaired waters were identified. Thus, costs may 
be overstated to the extent that some WWTPs discharging to currently 
impaired waters are included in EPA's estimate. The following table 
summarizes EPA's best estimate of the number of potentially affected 
municipal WWTPs that may require additional treatment to meet the 
numeric criteria supporting State designated uses.

                           Table VI(A)(1)(a)--Potential Additional Nutrient Controls for Municipal Wastewater Treatment Plants
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                  Number of dischargers
                                                               -----------------------------------------------------------------------------------------
                        Discharge type                             Additional        Additional        Additional      No incremental
                                                                 reduction in TN   reduction in TN   reduction in TP   controls needed        Total
                                                                   and TP \a\         only \b\          only \c\             \d\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Major.........................................................                11                 2                 9                21                43
Minor.........................................................                19                 1                 3                19                42
                                                               -----------------------------------------------------------------------------------------

[[Page 75795]]

 
    Total.....................................................                30                 3                12                40                85
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Includes dischargers without treatment processes capable of achieving the target levels or existing WLA for TN and TP, or for which the treatment
  train description is missing or unclear.
\b\ Includes dischargers with chemical precipitation only and those with a wasteload allocations under a TMDL for TP only.
\c\ Includes dischargers with MLE, four-stage Bardenpho, and BNR specified to achieve less than 3 mg/L and those with WLA under a TMDL for TN only.
\d\ Includes dischargers with A\2\ /O, modified Bardenpho, modified UCT, oxidation ditches, or other BNR coupled with chemical precipitation and those
  with WLAs under a TMDL for both TN and TP.

    An EPA study provides unit cost estimates for biological nutrient 
removal controls for various TN and TP performance levels.\173\ To 
estimate costs for WWTPs, EPA used the average capital and average 
operation and maintenance (O&M) unit costs for technologies that 
achieve an annual average of 3 mg/L or less for TN and/or 0.1 mg/L or 
less for TP. EPA also estimated a maximum cost for TN and TP reduction 
by using the highest cost TN and TP removal technology (estimated by 
finding the maximum of annualized costs for each technology option). 
Using average and maximum unit costs and multiplying unit costs by flow 
reported in EPA's PCS database, EPA estimated total capital costs could 
be approximately $108 million to $219 million and operation and 
maintenance (O&M) costs could be approximately $12 million per year to 
$18 million per year. Total annual costs would be approximately $22.3 
million per year to $38.1 million per year (capital costs annualized at 
7% over 20 years). The following table summarizes estimated costs for 
municipal WWTPs.
---------------------------------------------------------------------------

    \173\ U.S. EPA, 2008.

            Table VI(A)(1)(b)--Potential Incremental Costs for Municipal Waste Water Treatment Plants
----------------------------------------------------------------------------------------------------------------
                                                                                 O&M costs        Annual costs
                     Cost component                         Capital costs      (millions per      (millions per
                                                            (millions) \a\         year)              year)
----------------------------------------------------------------------------------------------------------------
Advanced BNR............................................         $108-$219            $12-$18        $22.3-$38.1
----------------------------------------------------------------------------------------------------------------
\a\ Low estimate represents average of unit costs; high estimate represents costs for treatment processes that
  results in the highest annualized costs (annualized capital at 7% over 20 years plus O&M).

    Using Florida's 2009 draft criteria as the baseline, municipal WWTP 
costs associated with this final rule are zero because treatment 
technologies needed to achieve Florida's 2009 draft criteria are the 
same as those needed to achieve the criteria in this final rule, even 
though the criteria themselves are somewhat different.
    After EPA published its proposed criteria for Florida (75 FR 4173), 
several organizations in Florida developed alternative estimates of 
compliance costs for WWTPs that were substantially higher than EPA's 
estimated costs. EPA disagrees with these cost estimates because they 
included costs for nutrient controls that are beyond what would be 
required by Florida to meet the new numeric criteria. For example, the 
Florida Water Environment Association Utility Council (FWEAUC) 
estimated annual costs for WWTPs would be approximately $2.0 billion 
per year to $4.4 billion per year.\174\ However, FWEAUC included in 
their analysis facilities that discharge to estuaries or coastal 
waters, and facilities that utilize deep well injection or generate 
reuse water which are not covered by this rule. FWEAUC also estimated 
costs to upgrade WWTPs regardless of the treatment that already exists 
at the facilities. Finally, FWEAUC assumed that all WWTPs will require 
expensive microfiltration and reverse osmosis control technology to 
comply with the new standard. EPA is not aware of any WWTPs in Florida 
that utilize microfiltration or reverse osmosis, even those discharging 
to currently impaired waters with TMDLs that have nutrient targets 
comparable to the criteria in this final rule. Thus, as noted above, 
EPA does not believe that this type of treatment technology for WWTPs 
in Florida has been demonstrated as practical or necessary. These 
differences appear to explain the discrepancy between FWEAUC and EPA 
estimates.
---------------------------------------------------------------------------

    \174\ Florida Water Environment Association Utility Council, 
2009, ``Numeric Nutrient Criteria Cost Implications for Florida 
POTWs,'' available electronically at: http://www.fweauc.org/PDFs/FWEAUC%20letter%20to%20Crist%20re%20NNC%20Cost%20Implications%20for%20Fla%20POTWs%20with%20attachment.pdf.
---------------------------------------------------------------------------

2. Industrial Point Source Costs
    Incremental costs for industrial dischargers are likely to be 
facility-specific and depend on process operations, existing treatment 
trains, and composition of waste streams. EPA previously estimated that 
108 industrial dischargers may potentially be affected by this rule 
(Table VI(A)). Of those 108 dischargers, EPA identified 38 of them as 
under an existing TMDL for nitrogen and/or phosphorus and 14 of them as 
discharging to waters listed as impaired for nutrients and/or dissolved 
oxygen. As with WWTPs, EPA assumed that industrial dischargers under an 
existing TMDL are currently meeting their wasteload allocation 
requirements and would not incur additional treatment costs, and costs 
at facilities discharging to currently impaired waters are not 
attributable to this final rule because those costs would be incurred 
absent the rule (under the baseline). To estimate the potential costs 
to the remaining 56 potentially affected

[[Page 75796]]

industrial facilities, EPA took a random sample of those facilities 
from each industry. EPA then analyzed their effluent data obtained from 
EPA's PCS database and other information in NPDES permits to determine 
whether or not they have reasonable potential to cause or contribute to 
an exceedance of the numeric nutrient criteria in this final rule. For 
those facilities with reasonable potential, EPA further analyzed their 
effluent data and estimated potential revised water quality based 
effluent limits (WQBEL) for TN and TP. If the data indicated that the 
facility would not be in compliance with the revised WQBEL, EPA 
estimated the additional nutrient controls those facilities would 
likely implement to allow receiving waters to meet State designated 
uses and the costs of those controls. EPA then calculated the average 
flow-based cost of compliance for the sampled facilities in each 
industrial category, and used the average cost to extrapolate to the 
potential cost for the total flow associated with all facilities in 
each category (see economic analysis support document for more 
information). Using this method, EPA estimated the potential costs for 
industrial dischargers could be approximately $25.4 million per year.

                                         Table VI(A)(2)--Potential Incremental Costs for Industrial Dischargers
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                      Number of      Average sample
                      Industrial category                        Total number of     facilities     cost  ($/mgd/yr)                      Total annual
                                                                   facilities          sampled             \a\                              costs \b\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Chemicals and Allied Products.................................                 9                 2           $14,100        $1,116,800  ................
Electric Services.............................................                 9                 2                 0  ................                $0
Food..........................................................                 7                 2           123,300  ................         1,390,000
Mining........................................................                10                 2           160,600        16,442,300  ................
Other.........................................................                17                 3                 0                 0  ................
Pulp and Paper................................................                 4                 1           117,300         6,466,800  ................
                                                               -----------------------------------------------------------------------------------------
    Total.....................................................                56                12  ................        25,415,900  ................
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Calculated by dividing total annual sample discharger costs by total sample discharger flow. Note that where flow for a sample discharger is not
  available, EPA used the average flow for dischargers in that category and discharger type (major or minor).
\b\ Represents average sample discharger unit cost multiplied by total flow of dischargers affected by the rule in each industrial category.

    Using Florida's 2009 draft criteria as the baseline, industrial 
discharger costs associated with this final rule is zero because 
treatment technologies needed to achieve the Florida's 2009 draft 
criteria are the same as those needed to achieve the criteria in this 
final rule, even though the criteria themselves are somewhat different.
    Several organizations in Florida developed alternative estimates of 
compliance costs for EPA's proposed rule that were substantially higher 
than EPA's estimated costs for industrial dischargers. EPA disagrees 
with these cost estimates because they assumed that facilities will 
need to install treatment technologies that are much more expensive 
than those that would likely be required by Florida to meet the numeric 
criteria. For example, FDEP estimated that the costs for industrial 
dischargers would be approximately $2.1 billion per year.\175\ However, 
FDEP assumed that every industrial facility would treat their total 
discharge volume using reverse osmosis which EPA believes is 
impractical and unnecessary. In addition, FDEP estimated costs for 
reverse osmosis on the basis of each facility's maximum daily discharge 
flow instead of its reported design capacity (in some cases the maximum 
daily flow was more than double the design capacity). Installing 
treatment technology to handle maximum daily flows would be unnecessary 
because equalization basins or storage tanks (used to temporarily hold 
effluent during peak flows) would be a less expensive compliance 
strategy. Finally, EPA found no indication that industrial facilities 
in Florida have installed reverse osmosis for the purpose of complying 
with a nutrient-related TMDL, even those TMDLs with nutrient targets 
comparable to the criteria in this final rule. These differences appear 
to explain the discrepancy between FDEP and EPA estimates.
---------------------------------------------------------------------------

    \175\ Florida Department of Environmental Protection, 2010, 
``FDEP Review of EPA's `Preliminary Estimate of Potential Compliance 
Costs and Benefits Associated with EPA's Proposed Numeric Nutrient 
Criteria for Florida','' p. 3.
---------------------------------------------------------------------------

B. Incrementally Impaired Waters

    To estimate nonpoint source incremental costs associated with State 
control requirements that may be necessary to assure attainment of 
designated uses, EPA first removed from further consideration any 
waters the State of Florida has already determined to be impaired or 
has established a TMDL and/or BMAP because these waters were considered 
part of the baseline for this analysis. EPA next identified Florida 
waters that may be identified as incrementally impaired using the 
criteria of this final rule, and then identified the watersheds 
surrounding those incrementally impaired waters. EPA analyzed FDEP's 
database of ambient water quality monitoring data and compared 
monitoring data for each waterbody with EPA's new criteria for TN and 
TP in lakes and flowing waters, and nitrate+nitrite concentrations in 
springs. To account for streams that may have downstream protection 
values (DPVs) as applicable criteria, streams intersecting lakes were 
assigned the applicable lake criteria. Costs may be overestimated 
because the method does not distinguish between upstream and downstream 
intersecting streams. Thus DPVs and additional controls may have been 
attributed to streams downstream of an impaired lake. EPA compiled the 
most recent five years of monitoring data, calculated the annual 
geometric mean for each waterbody identified by a waterbody 
identification number (WBID), and identified waters as incrementally 
impaired if they exceeded the applicable criteria in this final rule.

[[Page 75797]]

                         Table VI(B)--Summary of Potential Incrementally Impaired Waters
----------------------------------------------------------------------------------------------------------------
                                                         Number of water bodies
                Category                 ------------------------------------------------------       Total
                                                Lake           Stream \a\          Spring
----------------------------------------------------------------------------------------------------------------
Total in State..........................             1,310             3,901               126             5,337
Not Listed/Covered by TMDL \b\..........             1,099             3,608               119             4,826
Water Quality Monitoring Data for                      878             1,273                72             2,223
 Nutrients \c\..........................
Sufficient Data Available \d\...........               655               930                72             1,657
Potentially Exceeding Criteria                         148               153                24               325
 (incrementally impaired) \e\...........
----------------------------------------------------------------------------------------------------------------
\a\ Includes blackwater.
\b\ As reported in TMDL documents and FDEP.
\c\ Data within last 5 years meeting data quality requirements.
\d\ Annual geometric means based on at least 4 samples with one sample from May to September and one sample from
  October to April in a given year.
\e\ Annual geometric mean exceeding the applicable criteria more than once in a three year period.

C. Non-Point Source Costs

    To estimate the potential incremental costs associated with 
controlling nitrogen/phosphorus pollution from non-point sources, EPA 
identified land areas near incrementally impaired waters using GIS 
analysis. EPA first identified all the 10-digit hydrologic units (HUCs) 
in Florida that contain at least a de minimus area of an incrementally 
impaired WBID (WBIDs were GIS polygons), and excluding those HUCs that 
contain at least a de minimus area of a currently impaired WBID. EPA 
then identified land uses using GIS analysis of data obtained from the 
State of Florida.\176\
---------------------------------------------------------------------------

    \176\ Florida Geological Data Library, 2009, ``GIS Data: 
WBIDs,'' available electronically at: http://www.fgdl.org/download/index.html.
---------------------------------------------------------------------------

1. Costs for Urban Runoff
    EPA's GIS analysis indicates that urban land (excluding land for 
industrial uses covered under point sources) accounts for approximately 
seven percent of the land near incrementally impaired waters. EPA's 
analysis also indicates that urban runoff is already regulated on 
approximately one half of this land under EPA's storm water program 
requiring municipal storm sewer system (MS4) NPDES permits. Florida has 
a total of 28 large (Phase I) permitted MS4s serving greater than 
100,000 people and 131 small (Phase II) permitted MS4s serving less 
than 100,000 people. MS4 permits generally do not have numeric nutrient 
limits, but instead rely on implementation of BMPs to control 
pollutants in storm water to the maximum extent practicable. Even those 
MS4s in Florida discharging to impaired waters or under a TMDL 
currently do not have numeric limits for any pollutant.
    In addition to EPA's storm water program, several existing State 
rules are intended to reduce pollution from urban runoff. Florida's 
Urban Turf Fertilizer rule (administered by FDACS) requires a reduction 
in the amount of nitrogen and phosphorus that can be applied to lawns 
and recreational areas. Florida's 1982 storm water rule (Chapter 403 of 
Florida statues) requires storm water from new development and 
redevelopment to be treated prior to discharge through the 
implementation of BMPs. The rule also requires that older systems be 
managed as needed to restore or maintain the beneficial uses of waters, 
and that water management districts establish and implement other storm 
water pollutant load reduction goals. In addition, Chapter 62-40, 
F.A.C., ``Water Resource Implementation Rule,'' establishes that storm 
water design criteria adopted by FDEP and the water management 
districts shall achieve at least 80% reduction of the average annual 
load of pollutants that cause or contribute to violations of WQS (95% 
reduction for outstanding natural resource waters). The rule also 
states that the pollutant loading from older storm water management 
systems shall be reduced as necessary to restore or maintain the 
designated uses of waters.
    Although urban runoff is currently regulated under the statutes and 
rules described above, this final rule may indirectly result in changes 
to MS4 NPDES permit requirements for urban runoff so that Florida 
waters meet State designated uses. However, the combination of 
additional pollution controls required will likely depend on the 
specific nutrient reduction targets, the controls already in place, and 
the relative amounts of nitrogen/phosphorus pollution contained in 
urban runoff at each particular location. Because storm water programs 
are usually implemented using an iterative approach, with the 
installation of controls followed by monitoring and re-evaluation to 
determine the need for additional controls, estimating the complete set 
of pollution controls required to meet a particular water quality 
target would require site-specific analysis.
    Although it is difficult to predict the complete set of potential 
additional storm water controls that may be required to meet the 
numeric criteria that supports State designated uses in incrementally 
impaired waters, EPA estimated potential costs for additional treatment 
by assessing the amount of urban land that may require additional 
pollution controls for storm water. FDEP has previously assumed that 
all urban land developed after adoption of Florida's 1982 storm water 
rule would be in compliance with this final rule.\177\ Using this same 
assumption, EPA used GIS analysis of land use data obtained from the 
State of Florida \178\ to identify the amount of remaining urban land 
located near incrementally impaired waters. Using this procedure, EPA 
estimated that up to 48,100 acres of Phase I MS4 urban land, 30,700 
acres of Phase II MS4 urban land, and 30,600 acres of non-MS4 urban 
land may require additional storm water controls. EPA estimated costs 
of implementing controls for Phase I MS4 urban land based on a range of 
acres with 48,100 acres as the upper bound and zero acres as the lower 
bound because Phase I MS4 urban land already must implement controls to 
the ``maximum extent practicable'' and may not require additional 
controls if existing requirements are already fully implemented.
---------------------------------------------------------------------------

    \177\ Florida Department of Environmental Protection, 2010, 
``FDEP Review of EPA's `Preliminary Estimate of Potential Compliance 
Costs and Benefits Associated with EPA's Proposed Numeric Nutrient 
Criteria for Florida','' p. 9.
    \178\ Florida Geological Data Library, 2009.
---------------------------------------------------------------------------

    The cost of storm water pollution controls can vary widely. FDEP 
has assessed the cost of completed storm water projects throughout the 
State in dollars per acre treated.\179\ Capital costs

[[Page 75798]]

range from $62 to $60,300 per acre treated, with a median cost of 
$6,800 per acre. EPA multiplied FDEP's median capital cost per acre by 
the number of acres identified as requiring controls to estimate the 
potential additional storm water control costs that may be needed to 
meet the numeric criteria in this rule. EPA also used FDEP's estimate 
of operating and maintenance (O&M) costs as 5% of capital costs, and 
annualized capital costs using FDEP's discount rate of 7% over 20 
years. EPA estimates the total annual cost for additional storm water 
controls could range between approximately $60.5 and $108.0 million per 
year. The following table summarizes these estimates.
---------------------------------------------------------------------------

    \179\ Florida Department of Environmental Protection, 2010, 
appendix 3.

                                         Table VI(C)(1)--Potential Incremental Urban Storm Water Cost Scenarios
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Capital cost (millions $)                                  Annual cost (millions $)
              Land type                Acres needing controls \a\              \b\               O&M cost (millions $) \c\               \d\
--------------------------------------------------------------------------------------------------------------------------------------------------------
MS4 Phase I Urban...................  0-48,100...................  $0-$329.1..................  $0-$16.4...................  $0-$47.5
MS4 Phase II Urban..................  30,700.....................  $210.0.....................  $10.5......................  $30.3
Non-MS4 Urban.......................  30,600.....................  $208.8.....................  $10.4......................  $30.2
                                     -------------------------------------------------------------------------------------------------------------------
    Total...........................  61,300-109,400.............  $418.8-$747.0..............  $20.9-$37.4................  $60.5-$108.0
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Phase I MS4s range represents implementation of BMPs to the MEP resulting in compliance with EPA's rule or controls needed on all pre-1982 developed
  land; Phase II MS4s and urban land outside of MS4s represent controls needed on all pre-1982 developed land that is not low density residential.
\b\ Represents acres needing controls multiplied by median unit costs of storm water retrofit costs obtained from FDEP.
\c\ Represents 5% of capital costs.
\d\ Capital costs annualized at 7% over 20 years plus annual O&M costs.

    Using Florida's 2009 draft criteria as the baseline, potential 
incremental costs for urban storm water are estimated to range from 
$13.7 million per year to $27.2 million per year.
    Several organizations in Florida developed alternative estimates of 
compliance costs for EPA's proposed rule that were substantially higher 
than EPA's estimated costs for urban storm water. EPA disagrees with 
these cost estimates because they utilized incorrect assumptions about 
the areas that would have to implement controls. For example, FDEP 
estimated costs for urban storm water controls at $1.97 billion per 
year.\180\ However, FDEP estimated costs for pollution controls on 
urban land in watersheds that may not be listed as impaired, have 
already been listed as impaired, or will require controls under 
existing rules (e.g. land currently permitted under EPA's MS4 storm 
water program). In contrast, EPA estimated costs for urban storm water 
controls only for urban land with storm water flows to waters that may 
be listed as impaired as a result of this rule. This difference appears 
to explain the discrepancy between FDEP and EPA estimates.
---------------------------------------------------------------------------

    \180\ Florida Department of Environmental Protection, 2010, p. 
3.
---------------------------------------------------------------------------

2. Agricultural Costs
    EPA's GIS analysis of land use indicates that agriculture accounts 
for about 19 percent of the land near incrementally impaired waters. 
Agricultural runoff can be a source of phosphorus and nitrogen to lakes 
and streams through the application of fertilizer to crops and pastures 
and from animal wastes. Some agricultural practices may also contribute 
nitrogen and phosphorus to groundwater aquifers that supply springs. 
For waters impaired by nitrogen/phosphorus pollution, the 1999 Florida 
Watershed Restoration Act established that agricultural BMPs should be 
the primary instrument to implement TMDLs. Thus, additional waters 
identified by the State as impaired under this rule may result in State 
requirements or provisions to reduce the discharge of nitrogen and/or 
phosphorus to incrementally impaired waters through the implementation 
of BMPs.
    EPA estimated the potential costs of additional agricultural BMPs 
by evaluating land use data obtained from Florida's five water 
management districts. BMP programs designed for each type of 
agricultural operation and their costs were taken from a study of 
agricultural BMPs to help meet TMDL targets in the Caloosahatchee 
River, St. Lucie River, and Lake Okeechobee watersheds.\181\ Three 
types of BMP programs were identified in this study. The first program, 
called the ``Owner Implemented BMP Program,'' consists of a set of BMPs 
that land owners might implement without additional incentives. The 
second program, called the ``Typical BMP Program,'' is the set of BMPs 
that land owners might implement under a reasonably funded cost share 
program or a modest BMP strategy approach. The third program, called 
the ``Alternative Program,'' is a more expensive program designed to 
supplement the ``Owner Implemented Program'' and ``Typical Program'' if 
additional reductions are necessary.
---------------------------------------------------------------------------

    \181\ Soil and Water Engineering Technology, 2008, ``Nutrient 
Loading Rates, Reduction Factors and Implementation Costs Associated 
with BMPs and Technologies,'' (report prepared for South Florida 
Water Management District).
---------------------------------------------------------------------------

    The BMPs in the ``Owner Implemented Program'' and ``Typical 
Program'' are similar to the BMPs adopted by FDACS. EPA has found no 
indication that the ``Alternative BMP Program,'' which includes storm 
water chemical treatment, has been required in historically nutrient 
impaired watersheds with significant contributions from agriculture for 
which TMDLs have been developed (e.g. Lake Okeechobee). Therefore, for 
purposes of this analysis, EPA believes it is reasonable to assume that 
nutrient controls for agricultural sources are best represented by the 
``Owner Implemented Program'' and ''Typical Program'' described in the 
study used here.\182\ EPA estimated potential incremental costs of BMPs 
by multiplying the number of acres in each agricultural category by the 
sum of unit costs for the ``Owner Implemented Program'' and ``Typical 
Program.'' The following table summarizes the potential incremental 
costs of BMPs on agricultural lands near incrementally impaired lakes 
and streams for each agricultural category.
---------------------------------------------------------------------------

    \182\ Soil and Water Engineering Technology, 2008.

[[Page 75799]]

                    Table VI(C)(2)(a)--Potential Incremental BMP Costs for Lakes and Streams
----------------------------------------------------------------------------------------------------------------
                                                         ``Owner implemented
                                                      program'' plus ''typical      Total ``owner implemented
     Agricultural category        Area  (acres)\a\    program'' unit costs  ($/      program'' and ''typical
                                                              ac/yr)\e\              program'' costs  ($/yr)
----------------------------------------------------------------------------------------------------------------
Animal Feeding................           1,814-1,846                     18.56  33,671-34,260
Citrus........................         15,482-27,343                    156.80  2,427,652-4,287,343
Cow Calf Production (Improved        153,978-168,665                     15.84  2,439,007-2,671,656
 Pastures).
Cow Calf Production                    49,054-51,057                      4.22  207,203-215,663
 (Unimproved Pastures).
Cow Calf Production (Rangeland         74,449-75,790                      4.22  314,474-320,136
 and Wooded).
Row Crop......................           7,846-9,808                     70.40  552,352-690,453
Cropland and Pastureland             152,976-160,814                     27.26  4,169,512-4,383,135
 (general). \b\.
Sod/Turf Grass................                 2,007                     35.20  70,631
Ornamental Nursery............                   840                     70.00  58,783
Dairies.......................               583-621                    334.40  194,803-207,777
Horse Farms...................                 1,632                     15.84  25,857
Field Crop (Hayland)                 194,181-215,168                     18.56  3,603,996-3,993,521
 Production.
Other Areas \c\...............         54,499-67,364                     18.56  1,011,500-1,250,281
                               ---------------------------------------------------------------------------------
    Total \d\.................       709,340-782,954  ........................  15,109,436-18,209,496
----------------------------------------------------------------------------------------------------------------
\a\ Based on GIS analysis of land use data from five water management districts (for entire State) and FDACS BMP
  program NOI GIS data layer. Low end reflects acres in incrementally impaired HUCs (that are not included in
  HUCs for baseline impairment) that are not enrolled in BMPs under FDACS; high end reflects all acres in
  incrementally impaired HUCs, regardless of FDACS BMP enrollment.
\b\ ``Owner program'' and ``Typical Program'' BMP unit costs based on average costs for improved pastures,
  unimproved/wooded pasture, row crops, and field crops.
\c\ Includes FLUCCS Level 3 codes 2160, 2200, 2230, 2400, 2410, 2500, 2540, and 2550.
\d\ Excludes land not in production.
\e\ Soil and Water Engineering Technology, 2008, Nutrient Loading Rates, Reduction Factors and Implementation
  Costs Associated with BMPs and Technologies, Report prepared for South Florida Water Management District.

    In addition to estimating potential costs associated with 
agricultural BMPs to reduce nitrogen/phosphorus pollution to lakes and 
streams as described above, EPA estimated potential costs associated 
with BMPs to protect groundwater aquifers that supply water to springs. 
Fertilizer application and other agricultural practices can 
significantly increase nutrient loadings to springs, especially those 
springs supplied by relatively large groundwater aquifers. EPA 
evaluated the potential incremental costs to meet the numeric criteria 
in this final rule for springs by assuming that all applicable 
agricultural operations may be identified for implementation of 
nutrient management. Nutrient management reduces over application of 
fertilizers by determining realistic yield expectations, the nitrogen 
requirements necessary to obtain those yields, and adjusting 
application methods and timing to minimize nitrogen pollution.
    Nutrient management is a cost-effective way to reduce groundwater 
nitrogen, and may even result in cost savings to some farmers by 
reducing unnecessary fertilizer application. Therefore, for the purpose 
of this analysis, EPA assumed that all agricultural operations applying 
fertilizer to land would implement a nutrient management program, even 
those operations that are not associated with incrementally impaired 
waters. To estimate the potential costs of nutrient management, EPA 
estimated the amount of agricultural land where nutrient management 
could be applicable. EPA identified general agriculture \183\ and 
specialty crops \184\ as agricultural categories appropriate for 
nutrient management. EPA then used GIS analysis of land use data 
obtained from the State of Florida \185\ to identify the land areas 
categorized as general agriculture or specialty crops. Approximately 
4.9 million acres of agricultural land was identified as general 
agriculture and 1 million acres was identified as specialty crops. EPA 
further analyzed this agricultural land to identify the land near 
waters already listed as impaired for nutrients or under a TMDL. 
Similar to point sources, EPA assumed that nonpoint sources under an 
existing TMDL are currently meeting their load allocation requirements 
and would not incur additional costs, and costs to nonpoint sources 
associated with waters that are currently listed as impaired for 
nutrients are not attributable to this final rule because those costs 
would be incurred absent the rule (under the baseline). EPA also 
removed from this analysis land associated with incrementally impaired 
waters to avoid double counting the costs of BMPs that were already 
estimated to protect lakes and streams as described above. As a result 
of this analysis, approximately 1 million acres of general agriculture 
and 0.12 million acres of specialty crops was identified as land that 
may need to implement a nutrient management program to meet the numeric 
criteria for Florida springs in this final rule. Using unit costs of 
$10 per acre for general agriculture and $20 per acre for specialty 
crops obtained from Florida's Environmental Quality Incentive 
Program,\186\ EPA estimated the annual cost of nutrient management 
could be approximately $4.7 million per year. The following table 
summarizes the estimated potential incremental costs of BMPs on 
agricultural lands to protect State designated uses of springs on the 
basis of the criteria in this final rule.
---------------------------------------------------------------------------

    \183\ Cropland and pastureland, cow calf production (improved 
pastures), cropland and pastureland (general), dairies, horse farms, 
and field crop (hayland) production.
    \184\ Citrus, row crops, sod/turf grass, and ornamental nursery.
    \185\ Florida Geological Data Library, 2009.
    \186\ Florida Environmental Quality Incentive Program, 2009, 
``FY 2009 Statewide Payment Schedules,'' available electronically 
at: ftp://ftp-fc.sc.egov.usda.gov/FL/eqip/EQIP_FY2009PaySched_STATEWIDE_FINAL.pdf.

[[Page 75800]]

                                             Table VI(C)(2)(b)--Potential Incremental BMP Costs for Springs
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                  Acres identified
               Nutrient management program type                  Total acres in     for nutrient     Unit cost  ($/      Total cost     Annual cost  ($/
                                                                   Florida \a\     management \b\         acre)                             year) \c\
--------------------------------------------------------------------------------------------------------------------------------------------------------
General Agriculture...........................................         4,885,643         1,003,973               $10       $10,039,729        $3,825,656
Specialty Crop................................................         1,057,107           120,558                20         2,411,163           918,778
                                                               -----------------------------------------------------------------------------------------
    Total.....................................................         5,942,750         1,124,531  ................        12,450,892         4,744,433
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Excludes unimproved and woodland pastures, abandoned groves, aquaculture, tropical fish farms, open rural lands, and fallow cropland.
\b\ Calculated by subtracting agricultural land near incrementally impaired waters needing controls and agricultural land types participating in FDACS
  BMP program (assuming all Tri-county agricultural area land is regular nutrient management land) from total land use area in Florida.
\c\ Costs annualized at 7% over 3 years on basis of 3 year useful life.

The following table summarizes the total estimated potential 
incremental costs of BMPs on agricultural lands to meet the numeric 
criteria.

                Table VI(C)(2)(c)--Potential Annual Incremental Compliance Costs for Agriculture
----------------------------------------------------------------------------------------------------------------
                   Waterbody type                           Applicable acres                Annual costs
----------------------------------------------------------------------------------------------------------------
Lakes and Streams...................................               709,340-782,954       $15,109,400-$18,209,500
Springs.............................................                     1,124,531                    $4,744,400
                                                     -----------------------------------------------------------
    Total...........................................           1,833,871-1,907,485       $19,853,900-$22,953,900
----------------------------------------------------------------------------------------------------------------

    Using Florida's 2009 draft criteria as the baseline, potential 
incremental costs to agriculture are estimated to range from - $2.4 
million per year (a negative cost represents a cost savings) to $2.1 
million per year.
    Several organizations in Florida developed alternative estimates of 
compliance costs for EPA's proposed rule that were substantially higher 
than EPA's estimated costs for agriculture. EPA disagrees with these 
cost estimates because they use incorrect assumptions that overestimate 
costs. For example, the FDACS estimated that costs for agriculture 
would be approximately $0.9 billion to $1.6 billion per year.\187\ 
However, FDACS estimated BMP costs for all 13.6 million acres of 
agricultural land in the State of Florida. This land includes 
watersheds where waters are not expected to become listed as impaired 
due to this final rule (including coastal and estuarine watersheds), 
have already been listed as impaired, or will require controls under 
existing rules (e.g. animal feeding operations) and thus are not 
potentially affected by the rule. A portion of the agricultural land 
used by FDACS to estimate costs includes 4.8 million acres of forest, 
98.1% of which the State of Florida has claimed current BMPs 
effectively protect surface waters \188\ and thus EPA assumes will not 
require further controls. FDACS also estimated costs using the highest 
cost Alternative BMP program. The Alternative BMP Program, which 
includes storm water chemical treatment, is not yet required in 
historically nutrient-impaired watersheds with significant 
contributions from agriculture. Thus, it is uncertain whether such 
controls would be necessary or required to meet the new numeric 
criteria which are intended to implement Florida's existing narrative 
criteria. In contrast, EPA estimated costs for BMPs that are likely to 
be necessary, and only on the agricultural land identified as 
incrementally impaired under this final rule (although costs could be 
higher in some cases if further reductions are found to be necessary). 
These differences appear to explain the discrepancy between FDACS and 
EPA estimates.
---------------------------------------------------------------------------

    \187\ Florida Department of Agriculture and Consumer Services, 
2010, ``Consolidated Comments on Proposed EPA Numeric Nutrient 
Criteria for Florida's Lakes and Flowing Waters,'' p. 1, available 
electronically at: http://www.floridaagwaterpolicy.com/PDF/FINAL_FDACS_Consolidated_Comments_on_Docket_ID_No_EPA_HQ_OW_2009_0596.pdf.
    \188\ Florida Division of Forestry, Department of Agriculture 
and Consumer Services, 2010, ``Silviculture Best Management 
Practices: 2009 Implementation Survey Report,'' available 
electronically at: http://www.fl-dof.com/publications/2009_BMP_survey_report.pdf.
---------------------------------------------------------------------------

    The alternative BMP program, which includes storm water chemical 
treatment, is not yet required in the study basins which have 
significant contributions from agriculture. Thus, for this analysis, 
EPA assumed that nutrient controls for agricultural sources are best 
represented by the owner/typical programs.
3. Septic System Costs
    Some nutrient reductions from septic systems may be necessary for 
incrementally impaired waters to meet the numeric nutrient criteria in 
this final rule. Several nutrient-related TMDLs in Florida identify 
septic systems as a significant source of nitrogen/phosphorus 
pollution. Although properly operated and maintained systems can 
provide treatment equivalent to secondary wastewater treatment,\189\ 
even properly functioning septic systems can be expected to contribute 
to nitrogen/phosphorus pollution at some locations.\190\ Some of the 
ways to address pollution from septic systems may include greater use 
of inspection programs and repair of failing systems, upgrading 
existing systems to advanced nutrient removal, installation of 
decentralized cluster systems where responsible management entities 
would ensure reliable operation and maintenance, and connecting 
households and businesses to wastewater treatment plants. On the basis 
of current practice in the State of

[[Page 75801]]

Florida, EPA assumed that the most likely strategy to reduce nutrients 
loads from septic systems would be to upgrade existing conventional 
septic systems to advanced nutrient removal systems.
---------------------------------------------------------------------------

    \189\ Petrus, K., 2003, ``Total Maximum Daily Load for the 
Palatlakaha River to Address Dissolved Oxygen Impairment, Lake 
County, Florida,'' (Florida Department of Environmental Protection), 
available electronically at: http://www.dep.state.fl.us/water/tmdl/docs/tmdls/final/gp1/palatlakaha_river_do_tmdl.pdf.
    \190\ Florida Department of Environmental Protection, 2006, 
``TMDL Report. Nutrient and Unionized Ammonia TMDLs for Lake Jesup, 
WBIDs 2981 and 2981A,'' available electronically at: http://www.dep.state.fl.us/water/tmdl/docs/tmdls/final/gp2/lake-jessup-nutr_ammonia-tmdl.pdf.
---------------------------------------------------------------------------

    Septic systems in close proximity to surface waters are more likely 
to contribute nutrient loads to waters than distant septic systems. 
Florida Administrative Code provides that in most cases septic systems 
should be located at least 75 feet from surface waters (F.A.C. 64E-
6.005(3)). In addition, many of Florida's existing nutrient-related 
TMDLs identify nearby failing septic systems as contributing to 
nutrient impairments in surface waters.
    For this economic analysis, EPA assumed that some septic systems 
located near incrementally impaired lakes and streams may be required 
to upgrade to advance nutrient removal systems. However, the distance 
that septic systems can be safely located relative to these surface 
waters depends on a variety of site-specific factors. Because of this 
uncertainty, EPA conservatively assumed that septic systems located 
within 500 feet of any lake or stream in watersheds associated with 
incrementally impaired lakes or streams \191\ may be identified for 
upgrade from conventional to advanced nutrient removal systems.
---------------------------------------------------------------------------

    \191\ In this analysis EPA considered septic systems within 500 
feet of any lake or stream in an incrementally impaired watershed 
rather than only within 500 feet of an incrementally impaired lake 
or stream to account for the possibility of some downstream 
transport of nutrients from nearby streams that may not themselves 
be classified as incrementally impaired.
---------------------------------------------------------------------------

    EPA identified the number of septic systems within 500 feet of any 
lake or stream in watersheds associated with incrementally impaired 
lakes and streams using GIS analysis on data obtained from the Florida 
Department of Health \192\ that provides the location of active septic 
systems in the State. This analysis yielded 8,224 active septic systems 
that may potentially need to be upgraded from conventional to advanced 
nutrient removal systems to meet the numeric nutrient criteria in this 
final rule.
---------------------------------------------------------------------------

    \192\ Florida Department of Health, 2010, ``Bureau of Onsite 
Sewage GIS Data Files,'' available electronically at: http://www.doh.state.fl.us/Environment/programs/EhGis/EhGisDownload.htm.
---------------------------------------------------------------------------

    EPA evaluated the cost of upgrading existing septic systems to 
advanced nutrient removal systems. Upgrade costs range from $2,000 to 
$6,500 per system. For O&M costs, EPA relied on a study that compared 
the annual costs associated with various septic system treatment 
technologies including conventional onsite sewage treatment and 
disposal system and fixed film activated sludge systems.\193\ This 
study estimated the incremental O&M costs for an advanced system to be 
$650 per year. Thus, based on annual O&M costs of $650 and annualizing 
capital costs at 7% over 20 years, annual costs could range from 
approximately $800 to $1,300 for each upgrade. EPA estimated the total 
annual costs of upgrading septic systems by multiplying this range of 
unit costs with the number of systems identified for upgrade. Using 
this method, total annual costs for upgrading septic systems to meet 
State designated uses could range from $6.6 million per year to $10.7 
million per year.
---------------------------------------------------------------------------

    \193\ Chang, N., M. Wanielista, A. Daranpob, F. Hossain, Z. 
Xuan, J. Miao, S. Liu, Z. Marimon, and S. Debusk, 2010, ``Onsite 
Sewage Treatment and Disposal Systems Evaluation for Nutrient 
Removal,'' (Stormwater Management Academy, University of Central 
Florida).
---------------------------------------------------------------------------

    Using Florida's 2009 draft criteria as the baseline, potential 
incremental costs to upgrade septic systems are estimated to range from 
$1.3 million per year to 2.2 million per year.
    Several organizations in Florida developed alternative estimates of 
compliance costs for septic systems in EPA's proposed rule that were 
substantially higher than EPA's estimated costs. EPA disagrees with 
these cost estimates because they used incorrect assumptions that 
overestimate costs. For example, FDEP estimated that the costs related 
to septic systems would be approximately $0.9 billion per year to 2.9 
billion per year.\194\ However, FDEP assumed that 1,687,500 septic 
systems would require complete replacement (calculated as the 
proportion of all septic systems in the State of Florida on lots less 
than 3 acres assumed to discharge to fresh waters because all urban 
storm water discharges to freshwaters in that proportion). In contrast, 
EPA estimated costs to upgrade 8,224 septic systems to advanced 
nutrient removal systems that GIS analysis identified as located within 
500 feet of any water within an incrementally impaired watershed.
---------------------------------------------------------------------------

    \194\ Florida Department of Environmental Protection, 2010, p. 
3.
---------------------------------------------------------------------------

D. Governmental Costs

    This final rule may result in the identification of additional 
impaired waters that would require the development of additional TMDLs. 
As the principal State regulatory agency implementing water quality 
standard, the State of Florida may incur costs related to developing 
additional TMDLs. EPA's analysis identified 325 incrementally impaired 
waters potentially associated with this final rule. Because current 
TMDLs in Florida include an average of approximately two water bodies 
each, EPA estimates that the State of Florida may need to develop and 
adopt approximately 163 additional TMDLs. A 2001 EPA study found that 
the cost of developing a TMDL could range between $6,000 and $154,000, 
with an average cost of approximately $28,000.195 196 The 
low end of the range reflects the typical cost associated with TMDLs 
that are the easiest to develop and/or have the benefit of previous 
TMDL development for other pollutants. Because most of the 
incrementally impaired waters in EPA's analysis exceeded the criteria 
for both nitrogen and phosphorus, EPA assumed that TMDLs would need to 
be developed for both nitrogen and phosphorus. Under this assumption, 
EPA estimated the average TMDL cost to be approximately $47,000 
($28,000 on average for one pollutant, plus $6,000 on average for the 
other pollutant, and adjusting for inflation). For 163 TMDLs, total 
costs could be approximately $7.7 million. FDEP currently operates its 
TMDL schedule on a five-phase cycle that rotates through the five 
basins over five years. Under this schedule, completion of TMDLs for 
high priority waters will take 9 years; it will take an additional 5 
years to complete the process for medium priority waters. Thus, 
assuming all the incremental impairments are high priority and FDEP 
develops the new TMDLs over a 9-year period, annual costs could be 
approximately $851,000 per year. Using Florida's 2009 draft criteria as 
the baseline, potential incremental costs to develop additional TMDLs 
could be approximately $261,000 per year.
---------------------------------------------------------------------------

    \195\ U.S. EPA, 2001, ``The National Costs of the Total Maximum 
Daily Load Program (Draft Report),'' (EPA-841-D-01-003).
    \196\ EPA did not adjust these estimates to account for 
potential reductions in resources required to develop TMDLs as a 
result of this final rule.
---------------------------------------------------------------------------

    Should the State of Florida submit current TMDL targets as Federal 
site specific alternative criteria (SSAC) for EPA review and approval, 
EPA believes it is reasonable to assume that information used in the 
development of the TMDLs will substantially reduce the time and effort 
needed to provide a scientifically defensible justification for such 
applications. Thus, EPA assumed that incremental costs associated with 
SSAC, if any, would be minimal.
    Similarly, State and local agencies regularly monitor TN and TP in 
ambient waters. These data are the basis for the extensive IWR database 
the State of Florida maintains and which provided baseline water 
quality data for EPA's analyses. Because Florida is currently

[[Page 75802]]

monitoring TN, TP, and chlorophyll a concentrations in many waters, EPA 
assumed that this final rule is unlikely to have a significant impact 
on costs related to water quality monitoring activities.

E. Benefits

    Elevated concentrations of nutrients in surface waters can result 
in adverse ecological effects and negative economic impacts. Excess 
nutrients in water can cause eutrophication, which can lead to harmful 
(sometimes toxic) algal blooms, loss of rooted plants, and decreased 
dissolved oxygen, which can lead to adverse impacts on aquatic life, 
fishing, swimming, wildlife watching, camping, and drinking water. 
Excess nutrients can also cause nuisance surface scum, reduced food for 
herbivorous wildlife, fish kills, alterations in fish communities, and 
unsightly shorelines that can decrease property values. This final rule 
will help reduce nitrogen and phosphorus concentrations in lakes and 
flowing waters in Florida, and help improve ecological function and 
prevent further degradation that can result in substantial economic 
benefits to Florida citizens. EPA's economic analysis document 
entitled: Economic Analysis of Final Water Quality Standards for 
Nutrients for Lakes and Flowing Waters in Florida describes many of the 
potential benefits associated with meeting the water quality standards 
for nitrogen/phosphorus pollution in this rule.
    Florida waters have historically provided an abundance of 
recreational opportunities that are a vital part of the State's 
economy. In 2007, over 4.3 million residents and over 5.8 million 
visitors participated in recreational activities related to freshwater 
beaches in Florida.\197\ Of these residents and visitors, over 2.7 
million residents and approximately 1 million visitors used freshwater 
boat ramps, over 3 million residents and over 900,000 visitors 
participated in freshwater non-boat fishing, and over 2.6 million 
residents and almost 1 million visitors participated in canoeing and 
kayaking. Florida also ranks first in the nation in boat registrations 
with 973,859 recreational boats registered across the State.
---------------------------------------------------------------------------

    \197\ Florida Department of Environment, 2008, ``State 
Comprehensive Outdoor Recreation Plan (SCORP),'' available 
electronically at: http://www.dep.state.fl.us/parks/planning/default.htm.
---------------------------------------------------------------------------

    Tourism comprises one of the largest sectors of the Florida 
economy. In 2000, there were over 80.9 million visitors to the State of 
Florida, accounting for an estimated $65 billion in tourism 
spending.\198\ In 2008, tourism spending resulted in approximately $3.9 
billion in State sales tax revenues and contributed to the direct 
employment of more than 1 million Florida residents.\199\ Florida has 
ranked first in the nation for the number of in-State anglers, angler 
expenditures, angler-supported jobs, and State and local tax revenues 
derived from freshwater fishing.\200\ In 2006, total fishing-related 
expenditures by residents and nonresidents were more than $4.3 
billion.\201\ In addition, Florida's freshwater springs are an 
important inter- and intra-State tourist attraction.\202\ In 2002, Blue 
Springs State Park estimated over 300,000 visitors per year.
---------------------------------------------------------------------------

    \198\ VISIT Florida, 2010, available electronically at: http://media.visitflorida.org/research.php.
    \199\ VISIT Florida, 2010.
    \200\ Bonn, Mark A. and Frederick W. Bell., 2003, Economic 
Impact of Selected Florida Springs on Surrounding Local Areas. For 
Florida Department of Environmental Protection. Available 
electronically at: http://www.dep.state.fl.us/springs/reports/files/EconomicImpactStudy.doc.
    \201\ 2006 National Survey of Fishing, Hunting, and Wildlife-
Associated Recreation. Florida. U.S. Department of the Interior, 
Fish and Wildlife Service, and U.S. Department of Commerce, U.S. 
Census Bureau. Available electronically at: http://myfwc.com/docs/Freshwater/2006_Florida_NationalSurvey.pdf.
    \202\ Florida Department of Environmental Protection, 2008.
---------------------------------------------------------------------------

    Nitrogen/phosphorus pollution has contributed to severe water 
quality degradation of Florida waters. In 2010, the State of Florida 
reported approximately 1,918 miles of rivers and streams, and 378,435 
acres of lakes that were known to be impaired by nitrogen/phosphorus 
pollution (the actual number of waters impaired for nutrients may be 
higher because many waters were not assessed).\203\ As water quality 
declines, water resources have less recreational value. Waters impaired 
by nitrogen/phosphorus pollution may become unsuitable for swimming and 
fishing, and in some cases even unsuitable for boating. Nutrient-
impaired waters also are less likely to support native plant and animal 
species, further lowering their value as tourist destinations.\204\ 
Drinking water supplies may also be more expensive to treat as a result 
of nutrient impairments. Also, Florida citizens that depend on 
individual wells for their drinking water may need to consider whether 
on-site treatment is necessary to reduce elevated nitrate+nitrite 
levels. Freshwater springs are particularly at risk due to 
nitrate+nitrite.205 206 Silver Springs, the largest of 
Florida's springs, has experienced reduced ecosystem health and 
productivity over the past half century, due largely to 
nitrate+nitrite.\207\ Nutrient impairment, characterized by algal 
blooms, reduced numbers of native species, and lower water quality, in 
turn leads to reduced demand and lower values for these resources.
---------------------------------------------------------------------------

    \203\ Florida Department of Environmental Protection, 2010, 
``Integrated Water Quality Assessment for Florida: 2010 305(b) and 
303(d) List Update,'' available electronically at: http://www.dep.state.fl.us/water/docs/2010_Integrated_Report.pdf.
    \204\ Zheng, Lei and Michael J. Paul., 2006, Effects of 
Eutrophication on Stream Ecosystems. Available electronically at: 
http://n-steps.tetratech-ffx.com/PDF&otherFiles/literature_review/Eutrophication%20effects%20on%20streams.pdf.
    \205\ Florida Department of Environment, ``Deep Trouble: Getting 
to the Source of Threats to Springs,'' accessed on October 1, 2010 
at: http://www.floridasprings.org/protection/threats/.
    \206\ Munch, D.A., D.J. Toth, C. Huang, J.B. Davis, C.M. 
Fortich, W.L. Osburn, E.J. Phlips, E.L. Quinlan, M.S. Allen, M.J. 
Woods, P. Cooney, R.L. Knight, R.A. Clarke and S.L. Knight., 2006, 
``Fifty-year retrospective study of the ecology of Silver Springs, 
Florida,'' (SJ2007-SP4).
    \207\ Florida Department of Environment, 2008, Summary and 
Synthesis of the Available Literature on the Effects of Nutrients on 
Spring Organisms and Systems,'' available at: http://www.dep.state.fl.us/springs/reports/files/UF_SpringsNutrients_Report.pdf.
---------------------------------------------------------------------------

    Some of the benefits of reducing nitrogen and phosphorus 
concentrations can be monetized, at least in part, by translating these 
changes into an indicator of overall water quality (water quality 
index) and valuing these improvements in terms of willingness to pay 
(WTP) for the types of uses that are supported by different water 
quality levels. For this analysis, EPA used a Water Quality Index (WQI) 
approach to link specific pollutant levels with suitability for 
particular recreational uses. Using Florida water quality data, 
available information on WTP, and an analytical approach described in 
EPA's accompanying economic assessment report and supporting 
references, EPA estimated potential changes that would result from 
implementation of this final rule and their value to a distribution of 
full-time and part-time Florida residents. This approach recognizes 
that there are differences in WTP among a population and values for 
households. Using the mid-point WTP and current conditions as the 
baseline, total monetized benefits are estimated to be approximately 
$21.7 million per year for improvements to flowing waters and $6.6 
million per year for improvements to lakes for a total of $28.2 million 
per year. Although these monetized benefits estimates do not account 
for all potential economic benefits, they help to partially demonstrate 
the economic importance of restoring and protecting Florida waters from 
the impacts of nitrogen/phosphorus pollution.

[[Page 75803]]

F. Summary

    The following table summarizes EPA's estimates of potential 
incremental costs and benefits associated with additional State 
requirements to meet the numeric criteria that supports State 
designated uses. Because of uncertainties in the pollution controls 
ultimately implemented by the State of Florida, actual costs may vary 
depending on the procedures for assessing waters for compliance and the 
site-specific source reductions needed to meet the new numeric 
criteria.

            Table VI(F)(a)--Summary of Potential Annual Costs
                   [millions of 2010 dollars per year]
------------------------------------------------------------------------
              Source sector                        Annual costs
------------------------------------------------------------------------
Municipal Waste Water Treatment Plants..  $22.3-$38.1
Industrial Dischargers..................  $25.4
Urban Storm Water.......................  $60.5-$108.0
Agriculture.............................  $19.9-$23.0
Septic Systems..........................  $6.6-$10.7
Government/Program Implementation.......  $0.9
------------------------------------------------------------------------
    Total...............................  $135.5-$206.1
------------------------------------------------------------------------

VII. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

    Under Executive Order (EO) 12866 (58 FR 51735, October 4, 1993), 
this action is a ``significant regulatory action.'' Accordingly, EPA 
submitted this action to the Office of Management and Budget (OMB) for 
review under EO 12866 and any changes made in response to OMB 
recommendations have been documented in the docket for this action. 
This final rule does not establish any requirements directly applicable 
to regulated entities or other sources of nitrogen/phosphorus 
pollution. Moreover, existing narrative water quality criteria in State 
law already require that nutrients not be present in waters in 
concentrations that cause an imbalance in natural populations of flora 
and fauna in lakes and flowing waters in Florida.

B. Paperwork Reduction Act

    This action does not impose an information collection burden under 
the provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. 
Burden is defined at 5 CFR 1320.3(b). It does not include any 
information collection, reporting, or record-keeping requirements.

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an agency 
to prepare a regulatory flexibility analysis of any rule subject to 
notice and comment rulemaking requirements under the Administrative 
Procedure Act or any other statute unless the agency certifies that the 
rule will not have significant economic impact on a substantial number 
of small entities. Small entities include small businesses, small 
organizations, and small governmental jurisdictions.
    For purposes of assessing the impacts of this action on small 
entities, small entity is defined as: (1) A small business as defined 
by the Small Business Administration's (SBA) regulations at 13 CFR 
121.201; (2) a small governmental jurisdiction that is a government of 
a city, county, town, school district or special district with a 
population of less than 50,000; and (3) a small organization that is 
any not-for-profit enterprise that is independently owned and operated 
and is not dominant in its field.
    Under the CWA WQS program, States must adopt WQS for their waters 
and must submit those WQS to EPA for approval; if the Agency 
disapproves a State standard and the State does not adopt appropriate 
revisions to address EPA's disapproval, EPA must promulgate standards 
consistent with the statutory requirements. EPA also has the authority 
to promulgate WQS in any case where the Administrator determines that a 
new or revised standard is necessary to meet the requirements of the 
Act. These State standards (or EPA-promulgated standards) are 
implemented through various water quality control programs including 
the NPDES program, which limits discharges to navigable waters except 
in compliance with an NPDES permit. The CWA requires that all NPDES 
permits include any limits on discharges that are necessary to meet 
applicable WQS.
    Thus, under the CWA, EPA's promulgation of WQS establishes 
standards that the State implements through the NPDES permit process. 
The State has discretion in developing discharge limits, as needed to 
meet the standards. This final rule, as explained earlier, does not 
itself establish any requirements that are applicable to small 
entities. As a result of this action, the State of Florida will need to 
ensure that permits it issues include any limitations on discharges 
necessary to comply with the standards established in the final rule. 
In doing so, the State will have a number of choices associated with 
permit writing. While Florida's implementation of the rule may 
ultimately result in new or revised permit conditions for some 
dischargers, including small entities, EPA's action, by itself, does 
not impose any of these requirements on small entities; that is, these 
requirements are not self-implementing. Thus, I certify that this rule 
will not have a significant economic impact on a substantial number of 
small entities.

D. Unfunded Mandates Reform Act

    Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public 
Law 104-4, establishes requirements for Federal agencies to assess the 
effects of their regulatory actions on State, local, and Tribal 
governments and the private sector. Under section 202 of the UMRA, EPA 
generally must prepare a written statement, including a cost-benefit 
analysis, for proposed and final rules with ``Federal mandates'' that 
may result in expenditures to State, local, and Tribal governments, in 
the aggregate, or to the private sector, of $100 million or more in any 
one year. Before promulgating an EPA rule for which a written statement 
is needed, section 205 of the UMRA generally requires EPA to identify 
and consider a reasonable number of regulatory alternatives and adopt 
the least costly, most cost-effective or least burdensome alternative 
that achieves the objectives of the rule. The provisions of section 205 
do not apply when they are inconsistent with applicable law. Moreover, 
section 205 allows EPA to adopt an alternative other than the least 
costly, most cost-effective or least burdensome alternative if the 
Administrator publishes with the final rule an explanation of why that 
alternative was not adopted. Before EPA establishes any regulatory 
requirements that may significantly or uniquely affect small 
governments, including Tribal governments, it must have developed under 
section 203 of the UMRA a small government agency plan. The plan must 
provide for notifying potentially affected small governments, enabling 
officials of affected small governments to have meaningful and timely 
input in the development of EPA regulatory proposals with significant 
Federal intergovernmental mandates, and informing, educating, and 
advising small governments on compliance with the regulatory 
requirements.
    This final rule contains no Federal mandates (under the regulatory 
provisions of Title II of the UMRA) for State, local, or Tribal 
governments or the private sector. The State may use these resulting 
water quality criteria in implementing its water quality control

[[Page 75804]]

programs. This final rule does not regulate or affect any entity and, 
therefore, is not subject to the requirements of sections 202 and 205 
of UMRA.
    EPA determined that this final rule contains no regulatory 
requirements that might significantly or uniquely affect small 
governments. Moreover, WQS, including those promulgated here, apply 
broadly to dischargers and are not uniquely applicable to small 
governments. Thus, this final rule is not subject to the requirements 
of section 203 of UMRA.

E. Executive Order 13132 (Federalism)

    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, as 
specified in Executive Order 13132. EPA's authority and responsibility 
to promulgate Federal WQS when State standards do not meet the 
requirements of the CWA is well established and has been used on 
various occasions in the past. The final rule will not substantially 
affect the relationship between EPA and the States and territories, or 
the distribution of power or responsibilities between EPA and the 
various levels of government. The final rule will not alter Florida's 
considerable discretion in implementing these WQS. Further, this final 
rule will not preclude Florida from adopting WQS that EPA concludes 
meet the requirements of the CWA, after promulgation of the final rule, 
which would eliminate the need for these Federal standards and lead EPA 
to withdraw them. Thus, Executive Order 13132 does not apply to this 
final rule.
    Although section 6 of Executive Order 13132 does not apply to this 
action, EPA had extensive communication with the State of Florida to 
discuss EPA's concerns with the State's water quality criteria and the 
Federal rulemaking process.

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

    Subject to the Executive Order 13175 (65 FR 67249, November 9, 
2000) EPA may not issue a regulation that has Tribal implications, that 
imposes substantial direct compliance costs, and that is not required 
by statute, unless the Federal government provides the funds necessary 
to pay the direct compliance costs incurred by Tribal governments, or 
EPA consults with Tribal officials early in the process of developing 
the proposed regulation and develops a Tribal summary impact statement. 
EPA has concluded that this action may have Tribal implications. 
However, the rule will neither impose substantial direct compliance 
costs on Tribal governments, nor preempt Tribal law.
    In the State of Florida, there are two Indian Tribes, the Seminole 
Tribe of Florida and the Miccosukee Tribe of Indians of Florida, with 
lakes and flowing waters. Both Tribes have been approved for treatment 
in the same manner as a State (TAS) status for CWA sections 303 and 401 
and have Federally-approved WQS in their respective jurisdictions. 
These Tribes are not subject to this final rule. However, this rule may 
impact the Tribes because the numeric criteria for Florida will apply 
to waters adjacent to the Tribal waters. EPA met with the Seminole 
Tribe on January 19, 2010 and requested an opportunity to meet with the 
Miccosukee Tribe to discuss EPA's proposed rule, although a meeting was 
never requested by the Tribe.

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

    This action is not subject to EO 13045 (62 FR 19885, April 23, 
1997) because it is not economically significant as defined in EO 
12866, and because the Agency's promulgation of this rule will result 
in the reduction of environmental health and safety risks that could 
present a disproportionate risk to children.

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

    This rule is not a ``significant energy action'' as defined in 
Executive Order 13211, ``Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use'' (66 FR 28355 
(May 22, 2001)), because it is not likely to have a significant adverse 
effect on the supply, distribution, or use of energy.

I. National Technology Transfer Advancement Act of 1995

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (``NTTAA''), Public Law 104-113, section 12(d) (15 U.S.C. 
272 note) directs EPA to use voluntary consensus standards in its 
regulatory activities unless to do so would be inconsistent with 
applicable law or otherwise impractical. Voluntary consensus standards 
are technical standards (e.g., materials specifications, test methods, 
sampling procedures, and business practices) that are developed or 
adopted by voluntary consensus standards bodies. The NTTAA directs EPA 
to provide Congress, through OMB, explanations when the Agency decides 
not to use available and applicable voluntary consensus standards.
    This final rulemaking does not involve technical standards. 
Therefore, EPA is not considering the use of any voluntary consensus 
standards.

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

    Executive Order (EO) 12898 (Feb. 16, 1994) establishes Federal 
executive policy on environmental justice. Its main provision directs 
Federal agencies, to the greatest extent practicable and permitted by 
law, to make environmental justice part of their mission by identifying 
and addressing, as appropriate, disproportionately high and adverse 
human health or environmental effects of their programs, policies, and 
activities on minority populations and low-income populations in the 
United States.
    EPA has determined that this final rule does not have 
disproportionately high and adverse human health or environmental 
effects on minority or low-income populations because it will afford a 
greater level of protection to both human health and the environment if 
these numeric criteria are promulgated for Class I and Class III waters 
in the State of Florida.

K. Congressional Review Act

    The Congressional Review Act 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and to the Comptroller General of the 
United States. EPA will submit a report containing this rule and other 
required information to the U.S. Senate, the U.S. House of 
Representatives, and the Comptroller General of the United States prior 
to publication of the rule in the Federal Register. A ``major rule'' 
cannot take effect until 60 days after it is published in the Federal 
Register. This action is not a ``major rule'' as defined by 5 U.S.C. 
804(2). This rule is effective March 6, 2012, except for 40 CFR 
131.43(e), which is effective February 4, 2011.

List of Subjects in 40 CFR Part 131

    Environmental protection, Water quality standards, Nitrogen/
phosphorus pollution, Nutrients, Florida.

[[Page 75805]]

    Dated: November 14, 2010.
Lisa P. Jackson,
Administrator.

0
For the reasons set out in the preamble, 40 CFR part 131 is amended 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--[Amended]

0
2. Section 131.43 is added effective February 4, 2011 to read as 
follows:

Sec.  131.43  Florida.

    (a)-(d) [Reserved]
    (e) Site-specific alternative criteria. (1) The Regional 
Administrator may determine that site-specific alternative criteria 
shall apply to specific surface waters in lieu of the criteria 
established for Florida waters in this section, including criteria for 
lakes, criteria for streams, and criteria for springs. Any such 
determination shall be made consistent with Sec.  131.11.
    (2) To receive consideration from the Regional Administrator for a 
determination of site-specific alternative criteria, an entity shall 
submit a request that includes proposed alternative numeric criteria 
and supporting rationale suitable to meet the needs for a technical 
support document pursuant to paragraph (e)(3) of this section. The 
entity shall provide the State a copy of all materials submitted to 
EPA, at the time of submittal to EPA, to facilitate the State providing 
comments to EPA. Site-specific alternative criteria may be based on one 
or more of the following approaches.
    (i) Replicate the process for developing the stream criteria in 
this section.
    (ii) Replicate the process for developing the lake criteria in this 
section.
    (iii) Conduct a biological, chemical, and physical assessment of 
waterbody conditions.
    (iv) Use another scientifically defensible approach protective of 
the designated use.
    (3) For any determination made under paragraph (e)(1) of this 
section, the Regional Administrator shall, prior to making such a 
determination, provide for public notice and comment on a proposed 
determination. For any such proposed determination, the Regional 
Administrator shall prepare and make available to the public a 
technical support document addressing the specific surface waters 
affected and the justification for each proposed determination. This 
document shall be made available to the public no later than the date 
of public notice issuance.
    (4) The Regional Administrator shall maintain and make available to 
the public an updated list of determinations made pursuant to paragraph 
(e)(1) of this section as well as the technical support documents for 
each determination.
    (5) Nothing in this paragraph (e) shall limit the Administrator's 
authority to modify the criteria established for Florida waters in this 
section, including criteria for lakes, criteria for streams, and 
criteria for springs.

0
3. Section 131.43 is revised effective March 6, 2012 to read as 
follows:

Sec.  131.43  Florida.

    (a) Scope. This section promulgates numeric criteria for nitrogen/
phosphorus pollution for Class I and Class III waters in the State of 
Florida. This section also contains provisions for site-specific 
alternative criteria.
    (b) Definitions.--(1) Canal means a trench, the bottom of which is 
normally covered by water with the upper edges of its two sides 
normally above water.
    (2) Clear, high-alkalinity lake means a lake with long-term color 
less than or equal to 40 Platinum Cobalt Units (PCU) and Alkalinity 
greater than 20 mg/L CaCO3.
    (3) Clear, low-alkalinity lake means a lake with long-term color 
less than or equal to 40 PCU and alkalinity less than or equal to 20 
mg/L CaCO3.
    (4) Colored lake means a lake with long-term color greater than 40 
PCU.
    (5) Lake means a slow-moving or standing body of freshwater that 
occupies an inland basin that is not a stream, spring, or wetland.
    (6) Lakes and flowing waters means inland surface waters that have 
been classified as Class I (Potable Water Supplies) or Class III 
(Recreation, Propagation and Maintenance of a Healthy, Well-Balanced 
Population of Fish and Wildlife) water bodies pursuant to Rule 62-
302.400, F.A.C., excluding wetlands, and are predominantly fresh 
waters.
    (7) Nutrient watershed region means an area of the State, 
corresponding to drainage basins and differing geological conditions 
affecting nutrient levels, as delineated in Table 2.
    (8) Predominantly fresh waters means surface waters in which the 
chloride concentration at the surface is less than 1,500 milligrams per 
liter.
    (9) South Florida Region means those areas south of Lake Okeechobee 
and the Caloosahatchee River watershed to the west of Lake Okeechobee 
and the St. Lucie watershed to the east of Lake Okeechobee.
    (10) Spring means a site at which ground water flows through a 
natural opening in the ground onto the land surface or into a body of 
surface water.
    (11) State means the State of Florida, whose transactions with the 
U.S. EPA in matters related to 40 CFR 131.43 are administered by the 
Secretary, or officials delegated such responsibility, of the Florida 
Department of Environmental Protection (FDEP), or successor agencies.
    (12) Stream means a free-flowing, predominantly fresh surface water 
in a defined channel, and includes rivers, creeks, branches, canals, 
freshwater sloughs, and other similar water bodies.
    (13) Surface water means water upon the surface of the earth, 
whether contained in bounds created naturally or artificially or 
diffused. Water from natural springs shall be classified as surface 
water when it exits from the spring onto the Earth's surface.
    (c) Criteria for Florida waters--(1) Criteria for lakes. (i) The 
applicable criteria for chlorophyll a, total nitrogen (TN), and total 
phosphorus (TP) for lakes within each respective lake class are shown 
on Table 1.

                                                     Table 1
----------------------------------------------------------------------------------------------------------------
                           A                                     B                            C
----------------------------------------------------------------------------------------------------------------
                                                           Chl-a  (mg/L)
             Lake Color \a\  and Alkalinity                    \b,\*            TN  (mg/L)         TP  (mg/L)
----------------------------------------------------------------------------------------------------------------
Colored Lakes \c\......................................             0.020               1.27               0.05
                                                                                 [1.27-2.23]        [0.05-0.16]

[[Page 75806]]

 
Clear Lakes,...........................................             0.020               1.05               0.03
High Alkalinity \d\....................................                          [1.05-1.91]        [0.03-0.09]
Clear Lakes,...........................................             0.006               0.51               0.01
Low Alkalinity \e\.....................................                          [0.51-0.93]        [0.01-0.03]
----------------------------------------------------------------------------------------------------------------
\a\ Platinum Cobalt Units (PCU) assessed as true color free from turbidity.
\b\ Chlorophyll a is defined as corrected chlorophyll, or the concentration of chlorophyll a remaining after the
  chlorophyll degradation product, phaeophytin a, has been subtracted from the uncorrected chlorophyll a
  measurement.
\c\Long-term Color > 40 Platinum Cobalt Units (PCU)
\d\Long-term Color  20 mg/L CaCO3
\e\ Long-term Color L CaCO3
* For a given waterbody, the annual geometric mean of chlorophyll a, TN or TP concentrations shall not exceed
  the applicable criterion concentration more than once in a three-year period.

    (ii) Baseline criteria apply unless the State determines that 
modified criteria within the range indicated in Table 1 apply to a 
specific lake. Once established, modified criteria are the applicable 
criteria for all CWA purposes. The State may use this procedure one 
time for a specific lake in lieu of the site-specific alternative 
criteria procedure described in paragraph (e) of this section.
    (A) The State may calculate modified criteria for TN and/or TP 
where the chlorophyll a criterion-magnitude as an annual geometric mean 
has not been exceeded and sufficient ambient monitoring data exist for 
chlorophyll a and TN and/or TP for at least the three immediately 
preceding years. Sufficient data include at least four measurements per 
year, with at least one measurement between May and September and one 
measurement between October and April each year.
    (B) Modified criteria are calculated using data from years in which 
sufficient data are available to reflect maintenance of ambient 
conditions. Modified TN and/or TP criteria may not be greater than the 
higher value specified in the range of values in column C of Table 1 in 
paragraph (c)(1)(i) of this section. Modified TP and TN criteria may 
not exceed criteria applicable to streams to which a lake discharges.
    (C) The State shall notify the public and maintain a record of 
these modified lake criteria, as well as a record supporting their 
derivation. The State shall notify EPA Region 4 and provide the 
supporting record within 30 days of determination of modified lake 
criteria.
    (2) Criteria for streams. (i) The applicable instream protection 
value (IPV) criteria for total nitrogen (TN) and total phosphorus (TP) 
for streams within each respective nutrient watershed region are shown 
on Table 2.

                                 Table 2
------------------------------------------------------------------------
                                                           Instream
                                                       protection value
                                                           criteria
              Nutrient watershed region              -------------------
                                                      TN  (mg/  TP  (mg/
                                                         L)*       L)*
------------------------------------------------------------------------
Panhandle West a....................................      0.67      0.06
Panhandle East b....................................      1.03      0.18
North Central c.....................................      1.87      0.30
West Central d......................................      1.65      0.49
Peninsula e.........................................      1.54      0.12
------------------------------------------------------------------------
Watersheds pertaining to each Nutrient Watershed Region (NWR) were based
  principally on the NOAA coastal, estuarine, and fluvial drainage areas
  with modifications to the NOAA drainage areas in the West Central and
  Peninsula Regions that account for unique watershed geologies. For
  more detailed information on regionalization and which WBIDs pertain
  to each NWR, see the Technical Support Document.
a Panhandle West region includes: Perdido Bay Watershed, Pensacola Bay
  Watershed, Choctawhatchee Bay Watershed, St. Andrew Bay Watershed, and
  Apalachicola Bay Watershed.
b Panhandle East region includes: Apalachee Bay Watershed, and Econfina/
  Steinhatchee Coastal Drainage Area.
c North Central region includes the Suwannee River Watershed.
d West Central region includes: Peace, Myakka, Hillsborough, Alafia,
  Manatee, Little Manatee River Watersheds, and small, direct Tampa Bay
  tributary watersheds south of the Hillsborough River Watershed.
e Peninsula region includes: Waccasassa Coastal Drainage Area,
  Withlacoochee Coastal Drainage Area, Crystal/Pithlachascotee Coastal
  Drainage Area, small, direct Tampa Bay tributary watersheds west of
  the Hillsborough River Watershed, Sarasota Bay Watershed, small,
  direct Charlotte Harbor tributary watersheds south of the Peace River
  Watershed, Caloosahatchee River Watershed, Estero Bay Watershed,
  Kissimmee River/Lake Okeechobee Drainage Area, Loxahatchee/St. Lucie
  Watershed, Indian River Watershed, Daytona/St. Augustine Coastal
  Drainage Area, St. John's River Watershed, Nassau Coastal Drainage
  Area, and St. Mary's River Watershed.
* For a given waterbody, the annual geometric mean of TN or TP
  concentrations shall not exceed the applicable criterion concentration
  more than once in a three-year period.

    (ii) Criteria for protection of downstream lakes. (A) The 
applicable criteria for streams that flow into downstream lakes include 
both the instream criteria for total phosphorus (TP) and total nitrogen 
(TN) in Table 2 in paragraph (c)(2)(i) and the downstream protection 
value (DPV) for TP and TN derived pursuant to the provisions of this 
paragraph. A DPV for stream tributaries (up to the point of reaching 
water bodies that are not streams as defined by this rule) that flow 
into a downstream lake is either the allowable concentration or the 
allowable loading of TN and/or TP applied at the point of entry into 
the lake. The applicable DPV for any stream shall be determined 
pursuant to paragraphs (c)(2)(ii)(B), (C), or (D) of this section. 
Contributions from stream tributaries upstream of the point of entry 
location must result in attainment of the DPV at the point of entry 
into the lake. If the DPV is not attained at the point of entry into 
the lake, then the collective set of streams in the upstream watershed 
does not attain the DPV, which is an applicable water quality criterion 
for the water segments in the upstream watershed. The State or EPA may 
establish additional DPVs at upstream tributary locations that are 
consistent with attaining the DPV at the point of entry into the lake. 
The State or EPA also have discretion to establish DPVs to account for 
a larger watershed area (i.e., include waters beyond the point of 
reaching water bodies that are not streams as defined by this rule).
    (B) In instances where available data and/or resources provide for 
use of a scientifically defensible and protective lake-specific 
application of the

[[Page 75807]]

BATHTUB model, the State or EPA may derive the DPV for TN and/or TP 
from use of a lake-specific application of BATHTUB. The State and EPA 
are authorized to use a scientifically defensible technical model other 
than BATHTUB upon demonstration that use of another scientifically 
defensible technical model would protect the lake's designated uses and 
meet all applicable criteria for the lake. The State or EPA may 
designate the wasteload and/or load allocations from a TMDL established 
or approved by EPA as DPV(s) if the allocations from the TMDL will 
protect the lake's designated uses and meet all applicable criteria for 
the lake.
    (C) When the State or EPA has not derived a DPV for a stream 
pursuant to paragraph (c)(2)(ii)(B) of this section, and where the 
downstream lake attains the applicable chlorophyll a criterion and the 
applicable TP and/or TN criteria, then the DPV for TN and/or TP is the 
associated ambient instream levels of TN and/or TP at the point of 
entry to the lake. Degradation in water quality from the DPV pursuant 
to this paragraph is to be considered nonattainment of the DPV, unless 
the DPV is adjusted pursuant to paragraph (c)(2)(ii)(B) of this 
section.
    (D) When the State or EPA has not derived a DPV pursuant to 
paragraph (c)(2)(ii)(B) of this section, and where the downstream lake 
does not attain applicable chlorophyll a criterion or the applicable TN 
and/or TP criteria, or has not been assessed, then the DPV for TN and/
or TP is the applicable TN and/or TP criteria for the downstream lake.
    (E) The State and EPA shall maintain a record of DPVs they derive 
based on the methods described in paragraphs (c)(2)(ii)(B) and (C) of 
this section, as well as a record supporting their derivation, and make 
such records available to the public. The State and EPA shall notify 
one another and provide a supporting record within 30 days of 
derivation of DPVs pursuant to paragraphs (c)(2)(ii)(B) or (C) of this 
section.
    (3) Criteria for springs. The applicable nitrate+nitrite criterion 
is 0.35 mg/L as an annual geometric mean, not to be exceeded more than 
once in a three-year period.
    (d) Applicability. (1) The criteria in paragraphs (c)(1) through 
(3) of this section apply to lakes and flowing waters, excluding 
flowing waters in the South Florida Region, and apply concurrently with 
other applicable water quality criteria, except when:
    (i) State water quality standards contain criteria that are more 
stringent for a particular parameter and use;
    (ii) The Regional Administrator determines that site-specific 
alternative criteria apply pursuant to the procedures in paragraph (e) 
of this section; or
    (iii) The State adopts and EPA approves a water quality standards 
variance to the Class I or Class III designated use pursuant to Sec.  
131.13 that meets the applicable provisions of State law and the 
applicable Federal regulations at Sec.  131.10.
    (2) The criteria established in this section are subject to the 
State's general rules of applicability in the same way and to the same 
extent as are the other Federally-adopted and State-adopted numeric 
criteria when applied to the same use classifications.
    (e) Site-specific alternative criteria. (1) The Regional 
Administrator may determine that site-specific alternative criteria 
shall apply to specific surface waters in lieu of the criteria 
established in paragraph (c) of this section. Any such determination 
shall be made consistent with Sec.  131.11.
    (2) To receive consideration from the Regional Administrator for a 
determination of site-specific alternative criteria, an entity shall 
submit a request that includes proposed alternative numeric criteria 
and supporting rationale suitable to meet the needs for a technical 
support document pursuant to paragraph (e)(3) of this section. The 
entity shall provide the State a copy of all materials submitted to 
EPA, at the time of submittal to EPA, to facilitate the State providing 
comments to EPA. Site-specific alternative criteria may be based on one 
or more of the following approaches.
    (i) Replicate the process for developing the stream criteria in 
paragraph (c)(2)(i) of this section.
    (ii) Replicate the process for developing the lake criteria in 
paragraph (c)(1) of this section.
    (iii) Conduct a biological, chemical, and physical assessment of 
waterbody conditions.
    (iv) Use another scientifically defensible approach protective of 
the designated use.
    (3) For any determination made under paragraph (e)(1) of this 
section, the Regional Administrator shall, prior to making such a 
determination, provide for public notice and comment on a proposed 
determination. For any such proposed determination, the Regional 
Administrator shall prepare and make available to the public a 
technical support document addressing the specific surface waters 
affected and the justification for each proposed determination. This 
document shall be made available to the public no later than the date 
of public notice issuance.
    (4) The Regional Administrator shall maintain and make available to 
the public an updated list of determinations made pursuant to paragraph 
(e)(1) of this section as well as the technical support documents for 
each determination.
    (5) Nothing in this paragraph (e) shall limit the Administrator's 
authority to modify the criteria in paragraph (c) of this section 
through rulemaking.
    (f) Effective date. This section is effective March 6, 2012, except 
for Sec.  131.43(e), which is effective February 4, 2011.

[FR Doc. 2010-29943 Filed 12-3-10; 8:45 am]
BILLING CODE 6560-50-P
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