Form for Compliance with E.O. 12866 Docket Requirements

Title of Regulation: Water Quality Standards for the State of Florida’s Estuaries, Coastal 

Waters, and South Florida Inland Flowing Waters

 

Contact person: Erica Fleisig 

Phone number: 202-566-1057 

Was this regulation reviewed by OMB under Executive Order 12866 - Regulatory Planning 

and Review?

X Yes No 

If you checked “no”, you are done with this form. Simply place it in the docket for your 

regulation. If you checked “yes”, please fill out the remainder of the form before placing it in 

the docket. Also docket any relevant documents referenced in the form.

For regulations that are checked “Yes” above:

This regulation was reviewed by OMB under Executive Order 12866 - Regulatory Planning and 

Review. 

Attached is the draft regulation and any other documents sent to OMB for review, such as 

analyses and assessments. E.O. 12866 requires agencies to make these publicly available.

E.O. 12866 also requires agencies to identify the substantive changes between the draft 

regulation sent to OMB for review and the regulation subsequently announced [Please check the 

appropriate box below:] 

 X EPA made substantive changes to this regulation

(includes changes initiated by EPA or OMB). 

Attached is a document which: (1) identifies all the substantive changes made, and (2) 

notes those changes OMB suggested or recommended.

 No substantive changes were made to this regulation

Therefore, no further attachments are required.

If you have questions about this regulation, please call the EPA contact person listed above.
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EO12866_WQS Part 131 2040 AF21 NPRM FRN_20120110

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 131

[EPA-HQ-OW-2010-0222; FRL-XXXX-X]

RIN 2040-AF21

Water Quality Standards for the State of Florida’s Estuaries, Coastal Waters, and 

South Florida Inland Flowing Waters

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

SUMMARY: The U.S. Environmental Protection Agency (EPA or Agency) is proposing 

numeric water quality criteria to protect ecological systems and aquatic life from nitrogen 

and phosphorus pollution in estuaries and coastal waters within the State of Florida, and 

flowing waters in south Florida.

1 These proposed criteria apply to the above Florida 

waters that are designated as Class I, Class II or Class III waters and they 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: Comments must be received on or before [INSERT DATE 60 DAYS AFTER 

PUBLICATION IN THE FEDERAL REGISTER].

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-OW2010-0222, by one of the following methods:

 1 With the exception of the Florida Everglades Agricultural Area (EAA) and the Everglades Protection 

Area (EvPA), as defined in Florida Statute 373.4592 (1994), which are not covered in this rulemaking.
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1. www.regulations.gov: Follow the on-line instructions for submitting comments.

2. Email: ow-docket@epa.gov

3. Mail to: Water Docket, U.S. Environmental Protection Agency, Mail code: 

2822T, 1200 Pennsylvania Avenue, NW, Washington, DC 20460, Attention: 

Docket ID No. EPA-HQ-OW-2010-0222.

4. Hand Delivery: EPA Docket Center, EPA West Room 3334, 1301 Constitution 

Avenue, NW, Washington, DC 20004, Attention Docket ID No. EPA-HQ-OW2010-0222. Such deliveries are only accepted during the Docket’s normal hours 

of operation, and special arrangements should be made for deliveries of boxed 

information.

Instructions: Direct your comments to Docket ID No. EPA-HQ-OW-2010-0222. EPA’s 

policy is that all comments received will be included in the public docket without change 

and may be made available online at www.regulations.gov, including any personal 

information provided, unless the comment includes information claimed to be 

Confidential Business Information (CBI) or other information whose disclosure is 

restricted by statute. Do not submit information that you consider to be CBI or otherwise 

protected through www.regulations.gov or e-mail. The www.regulations.gov Web site is 

an “anonymous access” system, which means EPA will not know your identity or contact 

information unless you provide it in the body of your comment. If you submit an 

electronic comment, EPA recommends that you include your name and other contact 

information in the body of your comment and with any disk or CD-ROM you submit. If 

EPA cannot read your comment due to technical difficulties and cannot contact you for 
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clarification, EPA may not be able to consider your comment. Electronic files should 

avoid the use of special characters, any form of encryption, and be free of any defects or 

viruses. For additional information about EPA’s public docket visit the EPA Docket 

Center homepage at http://www.epa.gov/epahome/dockets.htm. 

Docket: All documents in the docket are listed in the www.regulations.gov index.

Although listed in the index, some information is not publicly available, e.g., CBI or 

other information whose disclosure is restricted by statute. Certain other material, such as 

copyrighted material, will be publicly available only in hard copy. Publicly available 

docket materials are available either electronically in www.regulations.gov or in hard 

copy at a docket facility. The Office of Water (OW) Docket Center is open from 8:30

a.m. until 4:30 p.m., Monday through Friday, excluding legal holidays. The OW Docket 

Center telephone number is (202) 566-2426, and the Docket address is OW Docket, EPA 

West, Room 3334, 1301 Constitution Avenue, 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: Erica Fleisig, U.S. EPA 

Headquarters, Office of Water, Mailcode: 4305T, 1200 Pennsylvania Avenue, NW, 

Washington, DC 20460; telephone number: (202) 566-1057; email address: 

fleisig.erica@epa.gov.

SUPPLEMENTARY INFORMATION: This supplementary information section is 

organized as follows: 

Table of Contents
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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. What Should I Consider as I Prepare My Comments for EPA?

E. How Can I Get Copies of This Document and Other Related Information?

II. Background

A. Nitrogen and Phosphorus Pollution

B. Statutory and Regulatory Background

C. Water Quality Criteria

D. EPA Determination Regarding Florida and EPA’s Rulemaking

III. Proposed Numeric Criteria for Florida’s Estuaries, Coastal Waters, and 

South Florida Inland Flowing Waters

A. General Information and Approaches

B. Proposed Numeric Criteria for Estuaries

C. Proposed Numeric Criteria for Coastal Waters

D. Proposed Numeric Criteria for South Florida Marine Waters

E. Proposed Numeric Criteria for South Florida Inland Flowing Waters

F. Applicability of Criteria When Final

IV. Under What Conditions Will Federal Standards Be Either Not Finalized or 

Withdrawn?

V. Alternative Regulatory Approaches and Implementation Mechanisms

A. Designating Uses
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B. Variances

C. Site-Specific Alternative Criteria

D. Compliance Schedules

VI. Economic Analysis 

A. Incrementally Impaired Waters

B. Point Source Costs

C. Non-point Source Costs

D. Governmental Costs

E. Summary of Costs

F. Benefits

VII. Statutory and Executive Order Reviews

A. Executive Orders 12866 (Regulatory Planning and Review) and 13563 

(Improving Regulation and Regulatory 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)
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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)

I. General Information

A. Executive Summary

Florida is known for its abundant and aesthetically beautiful natural resources, 

particularly its aquatic resources, which are very important to Florida’s economy. For 

example, Florida’s saltwater sport fishing industry contributes over $5 billion to the 

State’s economy and more than 54,000 jobs annually; the State's commercial saltwater 

fishing industry contributes over $1 billion and more than 10,000 jobs annually.

2 In 2007, 

nearly 11.3 million residents and 46.3 million visitors participated in recreational 

saltwater beach activities in Florida. Nearly 3.5 million residents and approximately 1.4 

million visitors used saltwater boat ramps, over 4.2 million residents and about 3 million 

visitors participated in saltwater non-boat fishing, and over 2.6 million residents and 

almost 1 million visitors participated in canoeing and kayaking.3

However, nitrogen and phosphorus pollution has contributed to serious water 

quality degradation affecting these aquatic resources in the State of Florida. Many people 

throughout Florida, whose livelihood depends on these recreational water activities, lose 

income when recreation, tourism, or fishing activities are adversely affected by nitrogen 

 2 Florida Fish and Wildlife Conservation Commission. 2011. The economic impact of saltwater fishing in 

Florida. <http://myfwc.com/conservation/value/saltwater-fishing>. Accessed December 2011.

3 FDEP. 2008. Chapter 5 – Outdoor Recreation Demand and Need. In Outdoor Recreation in Florida, 

2008: Florida’s Comprehensive Outdoor Recreation Plan, Final Draft. Florida Department of 

Environmental Protection, Division of Recreation and Parks, Tallahassee, FL. 

<http://www.dep.state.fl.us/parks/planning/forms/SCORP5.pdf>. Accessed December 2011.
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and phosphorus pollution. In the most recent Florida Department of Environmental 

Protection (FDEP) water quality assessment report, the Integrated Water Quality 

Assessment for Florida: 2010 305(b) Report and 303(d) List Update, FDEP describes 

widespread water quality impairment in Florida due to nitrogen and phosphorus 

pollution. FDEP’s 2010 report identifies approximately 1,918 miles of rivers and streams 

(about 14 percent of assessed river and stream miles), 378,435 acres of lakes (about 31

percent of assessed lake acres), 569 square miles (364,160 acres) of estuaries (about 23

percent of assessed estuarine area) and 102 square miles (65,280 acres) of coastal waters 

(about 1.5 percent of assessed coastal waters) as impaired by nutrients. These numbers 

may underestimate the extent of nutrient pollution in Florida as only 58 percent of 

Florida’s rivers and streams, 82 percent of Florida’s lakes, and 93 percent of Florida’s 

estuaries were assessed. The challenge of nitrogen and phosphorus pollution has been an 

ongoing focus for FDEP. However, despite FDEP’s efforts to evaluate and address

nitrogen and phosphorus pollution, it continues to cause substantial and widespread water 

quality degradation.4

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

nutrient water quality criteria are necessary to protect the designated uses that Florida has 

set for its Class I, Class II and Class III waters. The Agency considered (1) the State’s 

documented unique and threatened ecosystems, (2) the large number of waters that are 

impaired due to nitrogen and phosphorus pollution, and (3) the challenge associated with 

increasing nitrogen and phosphorus pollution due to expanding urbanization, agricultural 

 4 FDEP. 2010. Integrated Water Quality Assessment for Florida: 2010 305(b) Report and 303(d) List 

Update. September 2010.
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development, and a growing population.5 The 2009 determination also included EPA’s

evaluation of the State’s regulatory accountability system, which includes a combination 

of technology-based standards and point source control authority, as well as authority to 

establish enforceable controls for non-point sources.

In its determination, EPA concluded that Florida’s water quality program faces a 

significant challenge because its current approach to water quality assessment, listing, 

total maximum daily load (TMDL) development, and permitting depends upon resourceintensive and time-consuming site-by-site data collection and analysis to interpret the 

existing State narrative criterion under Subsection 62-302.530(47)(b), F.A.C.6 Florida 

uses this approach to (1) make water quality impairment determinations under CWA 

section 303(d), (2) set protective numeric nitrogen and phosphorus TMDL targets to 

guide restoration of impaired waters, (3) establish numeric nitrogen and phosphorus goals

to ensure protection and maintenance of non-impaired waters, and (4) support 

development of water quality-based effluent limitations (WQBELs) in permits. Based on

the scope and magnitude of impaired waters to be addressed, EPA determined that 

Florida’s narrative-based approach was insufficient to ensure protection of applicable 

designated uses.

In accordance with the terms of EPA’s January 14, 2009 determination, a

December 2009 Consent Decree responding to Florida stakeholder litigation focusing on 

the need for numeric nutrient criteria, and subsequent June 7, 2010 and September 30, 

 5 The U.S. Census estimates that Florida’s population is expected to grow nearly 80% between 2000 and 

2030. U.S. Census Bureau, Population Division, Interim State Population Projections, 2005.

<http://www.census.gov/population/projections/SummaryTabA1.pdf>.

6 “[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”
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2011 revisions to that Consent Decree (discussed in more detail in Section II.D), EPA is 

proposing criteria for estuaries and coastal waters within the State of Florida and inland 

flowing waters (e.g., rivers, streams, canals) in the South Florida Region7 with the 

exception of waters in the Everglades Agricultural Area (EAA)8 and the Everglades 

Protection Area (EvPA).

9

To develop these proposed numeric criteria for Florida’s estuaries, coastal waters, 

and south Florida inland flowing waters, the Agency conducted a detailed scientific 

analysis of the substantial amount of water quality data available from Florida’s extensive 

monitoring data set.

EPA concluded that an approach using relevant biological endpoints and multiple 

lines of evidence including stressor-response analyses, mechanistic modeling, and 

reference conditions was a strong and scientifically sound approach for deriving numeric 

criteria for estuaries, in the form of total nitrogen (TN), total phosphorus (TP) and 

chlorophyll a concentrations. EPA’s Science Advisory Board (SAB) supported this 

strategy of considering all available and relevant science and data. EPA’s methodology 

and the resulting proposed estuarine numeric nutrient criteria are presented in more detail 

in Section III.B of this notice of proposed rulemaking. 

For coastal waters on the Atlantic and Gulf coasts of Florida, EPA is proposing to 

use a combination of (1) a reference-based approach using chlorophyll a observations 

 7 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. 8 FL Statute Section 373.4592 (1994) subsection (2) Definitions: (e) "Everglades Agricultural Area" or 

"EAA" means the Everglades Agricultural Area, which are those lands described in FL Statute Section 

373.4592 (1994) subsection (15). 9 FL Statute Section 373.4592 (1994) subsection (2) Definitions: (h) "Everglades Protection Area" means 

Water Conservation Areas 1 (which includes the Arthur R. Marshall Loxahatchee National Wildlife 

Refuge), 2A, 2B, 3A, and 3B, and the Everglades National Park.
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developed from satellite remote sensing imagery and field data to calibrate the satellite 

remote sensing imagery and (2) a mechanistic modeling approach to determine 

chlorophyll a criteria. EPA chose the satellite remote sensing methodology to apply to all 

coastal areas of Florida except the Big Bend region and south Florida marine waters. In 

the Big Bend area of Florida, where satellite remote sensing predictions of chlorophyll a

were not possible due to reflectance that interferes with the remote sensing imagery in 

that area, EPA used mechanistic models to determine chlorophyll a criteria for these

coastal waters. EPA is proposing separate criteria for south Florida marine waters (which 

include both south Florida estuarine and coastal waters) because extensive monitoring 

data are available and significant bottom reflectance in the region confounds derivation of 

chlorophyll a from satellite remote sensing. EPA’s methodology and results for its 

proposed coastal criteria are presented in more detail in Section III.C.

For south Florida marine waters EPA is proposing a reference-based approach

utilizing extensive data from the South Florida Region to derive chlorophyll a, TN and 

TP criteria. EPA’s methodology and results for its proposed criteria for south Florida 

marine waters are presented in more detail in Section III.D.

EPA is proposing numeric criteria to ensure the attainment and maintenance of 

the water quality standards in downstream estuaries pursuant to the provisions of 40 CFR 

131.10(b). EPA examined a variety of modeling techniques and data to assess whether 

waters entering an estuary protect the water quality standards within the estuary. 

Accordingly, EPA is proposing an approach to derive TN and TP criteria expressed as 

downstream protection values (DPVs) at the points where inland flowing waters flow into 

estuaries, or marine waters in south Florida (hereinafter referred to as ‘pour points’).
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These proposed DPVs apply to all flowing waters that flow directly into estuaries or 

marine waters, including inland flowing waters in the South Florida Region. EPA’s 

proposed approach for deriving DPVs at the pour points involves an evaluation of the 

downstream estuary, water quality conditions at the pour point, and available mechanistic 

models. The proposed approaches for deriving DPVs in flowing waters are presented in 

more detail in Sections III.B., III.D., and III.E.

Finally, EPA is proposing to extend the approach finalized in 40 CFR 131.43(e)10

to allow development of Site-Specific Alternative Criteria (SSAC) for estuaries, coastal 

waters, and south Florida inland flowing waters. EPA’s rationale for extending these 

SSAC provisions is discussed in more detail in Section V.C.

EPA has incorporated sound science, local expertise, and substantial Floridaspecific data throughout the development of these proposed numeric criteria for nitrogen,

phosphorus, and chlorophyll a. Under the CWA and EPA's implementing regulations, 

numeric criteria must protect the designated use of a water body, ensure attainment and 

maintenance of downstream water quality standards, and must be based on sound 

scientific rationale (See CWA section 303(c), 40 CFR 131.10, and 40 CFR 131.11). In 

Florida, EPA relied upon peer-reviewed criteria development methodologies,

11 relevant

biological endpoints, and a substantial body of scientific analysis provided to EPA by 

 10 40 CFR 131.43(e) authorizes the derivation of Federal Site-Specific Alternative Criteria (SSAC) after 

EPA review and approval of applicant submissions of scientifically defensible criteria that meet the 

requirements of CWA section 303(c) and EPA’s implementing regulations at 40 CFR 131. 11 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. 2010. Using Stressor-Response Relationships to Derive Numeric Nutrient Criteria. EPA-820-S10-001. U.S. Environmental Protection Agency, Office of Water, Washington, DC.
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FDEP, as well as other federal, State and local partners such as the National Park Service;

National Oceanic and Atmospheric Administration; U.S. Geological Survey; Tampa Bay, 

Indian River Lagoon, Sarasota Bay and Charlotte Harbor National Estuary Programs; St. 

Johns River and South Florida Water Management Districts; and Florida International 

University.

EPA sought feedback on the scientific defensibility of the approaches outlined in 

this proposed rule through a Science Advisory Board (SAB) review.12 The SAB 

assembled a group of eighteen expert panelists to review EPA’s Methods and Approaches 

for Deriving Numeric Criteria for Nitrogen/Phosphorus Pollution in Florida’s Estuaries, 

Coastal Waters, and Southern Inland Flowing Waters.

13 The SAB recommendations14

strengthened the scientific basis of these proposed numeric criteria. A number of key 

interest groups presented their comments and views on the underlying science as part of 

the SAB review process. In addition, EPA met with several groups of stakeholders with 

local technical expertise to discuss potential approaches for deriving scientifically 

defensible numeric criteria. As discussed in more detail in the following sections, EPA 

believes that the proposed criteria in this rule will assure attainment of Florida’s existing 

designated uses and are based on sound and substantial scientific data and analyses.

B. Which Water Bodies Are Affected By This Rule?

 12 USEPA-SAB. 2011. Review of Methods and Approaches for Deriving Numeric Criteria for 

Nitrogen/Phosphorus Pollution in Florida’s Estuaries, Coastal Waters, and Southern Inland Flowing 

Waters. U.S. Environmental Protection Agency, Science Advisory Board, Washington, DC. 13 USEPA. 2010. Methods and Approaches for Deriving Numeric Criteria for Nitrogen/Phosphorus 

Pollution in Florida’s Estuaries, Coastal Waters, and Southern Inland Flowing Waters. U.S. 

Environmental Protection Agency, Office of Water, Washington, DC. 14 USEPA-SAB. 2011. Review of Methods and Approaches for Deriving Numeric Criteria for 

Nitrogen/Phosphorus Pollution in Florida’s Estuaries, Coastal Waters, and Southern Inland Flowing 

Waters. U.S. Environmental Protection Agency, Science Advisory Board, Washington, DC.
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EPA’s proposed rule applies to estuaries and coastal marine waters that have been 

classified by Florida as Class II (Shellfish Propagation or Harvesting) or Class III

(Recreation, Propagation and Maintenance of a Healthy, Well-Balanced Population of 

Fish and Wildlife), including tidal creeks and marine lakes. This proposed rule also 

applies to fresh flowing waters in the South Florida Region that have been classified by 

Florida as Class I (Potable Water Supplies) or Class III water bodies pursuant to Section 

62-302.400, F.A.C., excluding wetlands and flowing waters within the EvPA or the EAA. 

Pursuant to Subsection 62-302.400(4), F.A.C.,

15 “Class I, II, and III surface waters share 

water quality criteria established to protect fish consumption, recreation and the 

propagation and maintenance of a healthy, well-balanced population of fish and wildlife.” 

Florida currently has a narrative nutrient criterion16 established to protect these three uses 

and EPA is numerically interpreting Florida’s narrative criterion in this proposed 

rulemaking.

Florida has classified their water bodies, and EPA is not proposing to change any 

of Florida’s water body classifications with this regulation. The proposed criteria in this 

regulation would only apply to water bodies that are currently classified by Florida as 

Class I, II, or III and not to water bodies with other classifications such as Class III 

limited waters17 for which use attainability analyses (UAAs) and SSACs for nutrients 

have been established, or Class IV canals in Florida’s agricultural areas.

 15 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. 16 “[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”

17 Class III limited waters include waters that support fish consumption; recreation or limited recreation; 

and/or propagation and maintenance of a limited population of fish and wildlife; see Chapter 62-302.400(1) 

F.A.C, for more details.
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EPA is defining estuary to be consistent with Florida’s definition of estuary. As 

defined in Section 62-303.200, F.A.C., “estuary” shall mean “predominantly marine 

regions of interaction between rivers and nearshore ocean waters, where tidal action and 

river flow mix fresh and salt water.” Such areas include bays, mouths of rivers, and 

lagoons.

EPA is defining coastal waters based on Florida’s definitions of open coastal 

waters and open ocean waters, taking into account that CWA jurisdiction extends to three 

nautical miles from shore.

18 EPA’s definition of “coastal waters” is all marine waters 

extending to three nautical miles from shore that are not classified as estuaries. Consistent 

with Section 62-302.200, F.A.C., EPA’s proposed rule defines “marine waters” to mean 

surface waters in which the chloride concentration at the surface is greater than or equal 

to 1,500 milligrams per liter (mg/L).

EPA is defining tidal creeks as portions of streams that are affected by the ebb 

and flow of ocean tides. For another subset of marine waters, marine lakes, EPA is 

proposing to use the definition of “marine waters” and amend the definition of lakes 

included previously in Water Quality Standards for the State of Florida’s Lakes and 

Flowing Waters (40 CFR 131.43) to define a lake as a slow-moving or standing body of 

freshwater or marine water that occupies an inland basin that is not a stream, spring, or 

wetland.

 18 While CWA jurisdiction and therefore EPA’s proposed criteria extend only to three nautical miles from 

shore, Florida State jurisdiction extends beyond three nautical miles. Florida defines open coastal waters as 

“all gulf or ocean waters that are not classified as estuaries or open ocean waters.” Open ocean waters 

consist of “all surface waters extending seaward from the most seaward natural 90-foot (15-fathom) 

isobath” (Subsection 62-303.200, F.A.C.).
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EPA’s definition for “flowing waters” is consistent with Florida’s definition for 

streams. Stream, as defined previously in Water Quality Standards for the State of 

Florida’s Lakes and Flowing Waters (40 CFR 131.43), is defined as “a free-flowing, 

predominantly fresh surface water in a defined channel, and includes rivers, creeks, 

branches, canals, freshwater sloughs, and other similar water bodies.” Consistent with 

EPA’s definition in 40 CFR 131.43, EPA defines “canal” for this proposed rule to mean a

trench, the bottom of which is normally covered by water with the upper edges of its two 

sides normally above water. Also as defined in 40 CFR 131.43, “predominantly fresh 

waters” mean surface waters in which the chloride concentration at the surface is less 

than 1,500 mg/L.

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 estuaries, coastal waters and 

flowing waters in Florida could be indirectly affected by this rulemaking because water 

quality standards are used in determining National Pollutant Discharge Elimination 

System (NPDES) permit limits. Examples of categories and entities that may ultimately 

be affected are listed in the following table.

Category Examples of potentially affected entities

Industry Industries discharging pollutants to estuaries, coastal waters and flowing 

waters in the State of Florida.

Municipalities Publicly-owned treatment works discharging pollutants to estuaries, coastal 

waters and flowing waters in the State of Florida.

Stormwater Management 

Districts 

Entities responsible for managing stormwater runoff in the State of Florida.

This table is not intended to be exhaustive, but rather provides a guide for 

entities that may be affected by this action. Other types of entities not listed in the table, 
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such as non-point source contributors to nitrogen and phosphorus pollution in Florida’s

waters, may be affected through implementation of Florida’s water quality standards 

program (e.g., through Basin Management Action Plans (BMAPs)). Any parties or 

entities conducting activities within Florida watersheds covered by this proposed rule, or 

who depend upon or contribute to the water quality of the estuaries, coastal waters 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 examine this proposed

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. What Should I Consider as I Prepare My Comments for EPA?

1. Submitting CBI. Do not submit confidential business information to EPA through 

http://www.regulations.gov or e-mail. Clearly mark the part or all of the information that 

you claim to be CBI. For CBI information in a disk or CD-ROM that you mail to EPA, 

mark the outside of the disk or CD-ROM as CBI and then identify electronically within 

the disk or CD-ROM the specific information that is claimed as CBI. In addition to one 

complete version of the comment that includes information claimed as CBI, a copy of the 

comment that does not contain the information claimed as CBI must be submitted for 

inclusion in the public docket. Information so marked will not be disclosed except in 

accordance with procedures set forth in 40 CFR part 2.

2. Tips for Preparing Your Comments. When submitting comments, remember to:

• Identify the rulemaking by docket number and other identifying information 

(subject heading, Federal Register date, and page number).
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• Follow directions--The agency may ask you to respond to specific questions or 

organize comments by referencing a Code of Federal Regulations (CFR) part or 

section number.

• Explain why you agree or disagree; suggest alternatives and substitute language 

for your requested changes.

• Describe any assumptions and provide any technical information and/or data that 

you used.

• If you estimate potential costs or burdens, explain how you arrived at your 

estimate in sufficient detail to allow for it to be reproduced.

• Provide specific examples to illustrate your concerns, and suggest alternatives.

• Make sure to submit your comments by the comment period deadline identified.

E. 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-2010-0222. 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.
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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.E(1).

II. Background

A. Nitrogen and Phosphorus Pollution

1. What is Nitrogen and Phosphorus Pollution?

a. Overview of Nitrogen and Phosphorus Pollution

Excess loading of nitrogen and phosphorus to surface water bodies and 

groundwater is one of the leading causes of water quality impairments in the United 

States.19 The problem extends to both fresh and marine waters,20 leading to over 15,000 

 19 Dubrovsky et al. 2010. The Quality of Our Nation’s Water—Nutrients in the Nation’s Streams and 

Groundwater, 1992–2004. Circular 1350. U.S. Geological Survey National Water Quality Assessment 

Program, Reston, VA.

20 Smith et al. 2006. Eutrophication of freshwater and coastal marine ecosystems. Limnol. Oceanogr., 51(1, 

part 2):351-355.

Schindler, D.W. 2006. Recent advances in the understanding and management of eutrophication. 

Limnology and Oceanography 51:356–363.
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nutrient-related impairments in 49 states across the country—a figure that substantially 

understates the problem as many waters have yet to be assessed.21 Estuaries and coastal 

waters are especially vulnerable to nutrient pollution because they are the ultimate 

receiving waters for most major watersheds transporting nitrogen and phosphorus 

loadings from multiple upstream sources.22

The problem of nutrient pollution is not new. Over forty years ago, a 1969 report 

by the National Academy of Sciences23 noted that “[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 recreational and domestic uses of 

the water, detract from its natural beauty, and reduce nearby property values.” A 2000 

report by the National Research Council24 concluded that “...scientists, coastal managers, 

and public decisionmakers have come to recognize that coastal ecosystems suffer a 

number of environmental problems that can, at times, be attributed to the introduction of 

excess nutrients from upstream watersheds. The problems are caused by a complex chain 

of events and vary from site to site, but the fundamental driving force is the accumulation 

of nitrogen and phosphorus in fresh water on its way to the sea.” 

 21 Nationally, only 27% of rivers and streams and less than 50% of lakes, reservoirs, and ponds have been 

assessed for impairment (USEPA 2011).

USEPA. 2011. Watershed Assessment, Tracking & Environmental Results. 

<http://iaspub.epa.gov/waters10/attains_nation_cy.control>. Accessed December 2011. 22 Bricker et al. 2007. Effects of Nutrient Enrichment in the Nation’s Estuaries: A Decade of Change. 

National Estuarine Eutrophication Assessment. Silver Spring, MD.; NRC 2000 23 National Academy of Sciences. 1969. Eutrophication: Causes, Consequences, Correctives. National 

Academy of Sciences, Washington, DC. 24 NRC. 2000. Clean Coastal Waters: Understanding and Reducing the Effects of Nutrient Pollution. 

National Research Council, National Academy of Sciences.
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Florida has long struggled with nutrient impacts to its surface and ground waters 

and these impacts are provided in detail in the following sections. Florida's flat 

topography makes Florida particularly susceptible to this pollution because water moves 

more slowly over the landscape, allowing time for nitrogen and phosphorus pollution to 

accumulate in waterbodies and cause eutrophication. Florida’s climate also contributes to 

increased run-off, due to high rainfall and provides ideal conditions for eutrophication,

when excess nutrients are available, with moderate to high annual temperature and ample 

sunlight.

25 In FDEP’s 2010 Integrated Water Quality Assessment for Florida: 2010

305(b) Report and 303(d) List Update, nutrients are ranked as the third major cause of 

estuary impairments by impaired square miles26 and the fifth major cause of impairments 

in coastal waters.27 In 2010, Florida assessed all of its coastal waters, and 93 percent of 

its estuarine waters for at least one parameter.28 FDEP documents nutrient impairments 

in 569 square miles (364,160 acres) of estuaries (about 23 percent of the estuarine area

assessed by Florida) and 102 square miles (65,280 acres) of coastal waters (about 1.5

percent of the assessed coastal waters). Together, the total acres of impaired estuaries and 

coastal waters (429,940 acres) are greater than the total acres of impaired lakes (378,435 

acres).29

 25 Perry, W. B. 2008. Everglades restoration and water quality challenges in south Florida. Ecotoxicology 

17:569-578. 26 First, second, and fourth major causes of estuary impairments by impaired square miles are mercury in 

fish, bacteria in shellfish, and fecal coliform, respectively. 27 FDEP. 2010. Integrated Water Quality Assessment for Florida: 2010 305(b) Report and 303(d) List 

Update. Florida Department of Environmental Protection. 

<http://www.dep.state.fl.us/water/docs/2010_Integrated_Report.pdf>. Accessed July 2011.

28 FDEP. 2010. Integrated Water Quality Assessment for Florida: 2010 305(b) Report and 303(d) List 

Update. Florida Department of Environmental Protection.

<http://www.dep.state.fl.us/water/docs/2010_Integrated_Report.pdf>. Accessed July 2011.

29 FDEP. 2010. Integrated Water Quality Assessment for Florida: 2010 305(b) Report and 303(d) List 

Update. Florida Department of Environmental Protection. 

<http://www.dep.state.fl.us/water/docs/2010_Integrated_Report.pdf>. Accessed July 2011.
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FDEP noted in its 2008 Integrated Water Quality Assessment for Florida: 2008 

305(b) Report and 303(d) List Update that nutrient pollution poses several challenges in 

Florida. FDEP stated that “The close connection between surface and groundwater, 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 non-point source pollution associated 

with increased population and development. Increasing pollution from urban stormwater 

and agricultural activities is having other significant effects.” 30

To better understand the nitrogen and phosphorus pollution problem in Florida, 

EPA looked at trends in the data Florida uses to create its Integrated Water Quality 

Reports,

31 and found increasing concentrations of nitrogen and phosphorus compounds in 

Florida waters over the 12 year period from 1996-2008. Florida’s Impaired Waters Rule 

(IWR) data indicate that levels of total nitrogen have increased approximately 20 percent

from a state-wide average of 1.06 mg/L in 1996 to 1.27 mg/L in 2008 and average statewide total phosphorus levels have increased approximately 40 percent from an average of 

0.108 mg/L in 1996 to 0.151 mg/L in 2008.

On a national scale, the primary sources of nitrogen and phosphorus pollution can 

be grouped into five major categories: (1) urban and suburban stormwater runoff—

sources associated with residential and commercial land use and development; (2) 

 30 FDEP. 2008. Integrated Water Quality Assessment for Florida: 2008 305(b) Report and 303(d) List 

Update. Florida Department of Environmental Protection. 

<http://www.dep.state.fl.us/water/docs/2008_Integrated_Report.pdf>. Accessed July 2011.

31 IWR Run 40. Updated through February 2010.
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municipal and industrial waste water discharges; (3) row crop agriculture and fertilizer 

use; (4) livestock production and manure management practices; and (5) atmospheric 

deposition resulting from nitrogen oxide emissions from fossil fuel combustion and 

ammonia emissions from row crop agriculture and livestock production. Land use and 

land cover in watersheds across much of the nation has been altered such that now a 

higher fraction of nitrogen and phosphorus applied to the landscape reaches surface and 

groundwater resources. These sources contribute loadings of anthropogenic nitrogen and 

phosphorus to surface and groundwaters, causing far-reaching impacts to aquatic 

ecosystems and imbalances in the natural populations of aquatic flora and fauna.32

In general, the major sources of nitrogen and phosphorus pollution in Florida are 

the same as those found at the national scale: urban and suburban stormwater runoff, 

wastewater discharges, row crop agriculture, livestock production, and atmospheric 

deposition. In nearly half of the estuaries examined for this rulemaking, urban or 

stormwater runoff is a major contributor of nitrogen and phosphorus pollution. As is the 

case with much of the southern United States, Florida’s population continues to grow, 

with Florida among the top ten fastest growing states. Florida’s population growth is 

concentrated in major cities and along the coast. As populations grow, increased stress is 

put on all ecosystems, with particularly harmful impacts to coastal areas and wetlands. As 

of 2005, Florida’s highest population density was along its eastern coast, and there has 

been significant population expansion along the western coast from Tampa to the south. 

In 2005, one study estimated that 7 percent of Florida’s area had total impervious area 

greater than 20 percent, and of that, a quarter of that land had total impervious area

 32 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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greater than 40 percent. Increased impervious cover can impact water quality, including 

coastal areas, wetlands, and other water ecosystems.33

As an example of the impact of stormwater on coastal waters, a recent report 

issued in 2010 by the Sarasota Bay Estuary Program indicates that in Sarasota Bay 

nutrients are primarily transported to the estuary by stormwater runoff and contaminated 

groundwater. An examination of 2008 loads to the estuary showed that the relative source 

contributions of key sources varied within the estuary. In all five segments of the estuary, 

runoff was the largest contributor to the nutrient load. For instance, in Sarasota Bay, 

runoff accounted for about 42 percent. In Blackburn Bay, runoff accounted for nearly 60

percent of the nutrient load.34 According to the Tampa Bay Estuary Program, the largest 

source of nitrogen to Tampa Bay is runoff (63 percent of total nitrogen loadings to 

Tampa Bay, 1999–2003).35 

Wastewater is also a significant contributor of nitrogen and phosphorus pollution. 

In Florida, there are 443 domestic (not including septic systems) and industrial 

wastewater dischargers with individual NPDES permits.

36 Of those facilities, 198 are 

classified as domestic (municipal) wastewater facilities, which treat sanitary wastewater 

or sewage from homes, business buildings, and institutions. The other 245 facilities are 

 33 Exum, L.R., S.L. Bird, J. Harrison, C.A. Perkins. 2005. Estimating and Projecting Impervious Cover in 

the Southeastern United States. U.S. Environmental Protection Agency. EPA/600/R-05/061. Washington, 

DC.

34 SBEP. 2010. Numeric Nutrient Criteria for Sarasota Bay. Sarasota Bay Estuary Program. 

<http://www.sarasotabay.org/documents/SBEP-NNC-Final-Report.pdf>. Accessed August 2011. 35 TBEP. No date. State of the Bay: Water and Sediment Quality. Tampa Bay Estuary Program. <

http://www.tbep.org/tbep/stateofthebay/waterquality.html>. Accessed January 2012.

36 United States Environmental Protection Agency (U.S. EPA). 2011. Permit Compliance System 

Database. http://www.epa.gov/enviro/facts/pcs/customized.html. Accessed June 2011.

There are also 34,508 dischargers covered under generic or general permits, which FDEP regulates based 

on categories of wastewater facilities or activities that involve the same or similar types of operations or 

wastes.
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Page 24 of 191

classified as industrial wastewater facilities. About one third of Florida’s population uses 

on-site sewage treatment and disposal (septic tanks) to treat wastewater.

37

Facilities with NPDES permits either discharge to surface waters or ground 

waters, including land application, beneficial reuse of reclaimed water, and deep well 

injection. In Florida, less than a quarter of individually permitted domestic and industrial 

facilities are allowed to discharge to surface waters. Domestic wastewater treatment 

facilities permitted by the Florida DEP produce over 1.5 billion gallons of treated effluent 

and reclaimed water per day, with a total treatment capacity of over 2.5 billion gallons 

per day. Eighteen percent of domestic wastewater treatment facilities have treatment 

capacities greater than 500,000 gallons per day, whereas 73 percent of domestic 

wastewater treatment facilities have capacities less than 100,000 gallons per day.38

In some areas, wastewater has been cited as impacting water quality. A 2003 

analysis of nitrogen loads from septic systems Sarasota County found that 45,000 septic 

systems contribute four times as much nitrogen to Sarasota Bay as the city of Sarasota’s 

wastewater treatment plant. On the east coast of Florida, septic systems contribute an 

estimated 1.5 million pounds of nitrogen per year to Florida’s Indian River Lagoon.39

There have been some successes in reducing the impact of wastewater on coastal waters. 

In Tampa Bay, wastewater treatment plants were one of the major sources of nitrogen 

 37 FDEP. 2011. General Facts and Statistics about Wastewater in Florida. 

<http://www.dep.state.fl.us/water/wastewater/facts.htm>. Accessed January 2012. 38 FDEP. 2011. Wastewater Program. Florida Department of Environmental Protection. 

<http://www.dep.state.fl.us/water/wastewater/index.htm> Accessed January 2012.

39 U.S. Environmental Protection Agency (USEPA). 2003. EPA Voluntary National Guidelines for 

Management of Onsite and Clustered (Decentralized) Wastewater Treatment Systems. EPA-832-B-03-001. 

U.S. Environmental Protection Agency, Office of Wastewater Management, Washington, DC. 

<http://www.epa.gov/owm/septic/pubs/septic_guidelines.pdf>. Accessed August 2011.
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Page 25 of 191

prior to the institution of tertiary nitrogen removal, and this treatment has partially 

contributed to an improvement in Tampa Bay’s water quality.

40

Agricultural runoff is also a significant contributor of nitrogen and phosphorus 

pollution. Nationally, Florida is ranked 19th for the number of farms and tied at 30th for 

the amount of total farm land. Florida ranks 19th for the total number of cattle produced 

(1.63 million dairy and beef cattle as of January 1, 2001) and ranks 13th among states for 

the number of chickens raised (10.1 million layers, and 57 million broilers as of 

December 2010). In January 2010, 15,000 hogs were raised on Florida farms. The top 

cattle producing counties are Okeechobee, Osceola, Highlands, Polk, and Hardee 

counties.41 Florida is also a major producer of citrus and field crops (including cotton, 

hay, peanuts, wheat, vegetables, melons, berries, and sugarcane). In 2009–2010, 65 

percent of U.S. citrus production came from Florida (predominantly in Polk, Hendry, 

DeSoto, and Highlands counties), and in 2010 the total harvested planted acreage of field 

crops was 599,000 and 654,000, respectively (with top production of corn, peanuts, and 

cotton concentrated in the panhandle and northern regions of Florida and other 

vegetables, melons, and berries grown in the throughout the state). 

A 2007 report by NOAA cited agriculture as a major contributor of nutrients 

influencing eutrophication in the South Atlantic and Gulf of Mexico regions (both of 

which include Florida’s coastal waters). NOAA reported that Gulf of Mexico waters were 

impacted by both livestock and crop agriculture, and the report specified that waters on 

 40 Johansson and Greening 2000 41 FDACS. 2011. Florida Agriculture by the Numbers. Florida Department of Agriculture and Consumer 

Services. <http://www.floridaagriculture.com/pubs/pubform/pdf/Florida_Agricultural_Statistical_Directory.pdf> Accessed January

2012.
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Page 26 of 191

Florida’s east coast were receiving nutrient inputs from both row crops (e.g., citrus, sugar 

cane, cotton) and livestock agriculture (e.g., cattle and poultry farms). 42 Other sources 

also note that agricultural activities can be a contributor of nitrogen and phosphorus 

pollution in Florida’s coastal waters. According to the Tampa Bay Estuary Program, 

approximately 12 percent of the nitrogen load to Tampa Bay is from agriculture.43

There have been a number of studies examining impacts to water quality in 

locations across Florida. This includes Biscayne Bay, located on the southeast coast of 

Florida, adjacent to Miami. Nutrient enrichment in the Bay comes from a number of key 

sources: stormwater runoff from urban areas, discharges from the Black Point Landfill 

and Sewage Treatment Plant, agricultural runoff from canals in the South Dade 

agricultural basin, and contaminated groundwater.44 In the area surrounding the Bay, the 

sources of nitrogen and phosphorus pollution vary geographically. In the northern section 

of the Bay, there are inputs from five canals, a landfill, and urban runoff. The southern 

section of the bay has a greater contribution from agricultural sources.45 In one study, 

researchers found that canals conveying waters from agricultural and urban areas 

 42 Bricker, S., B. Longstaff, W. Dennison, A. Jones, K. Boicourt, C. Wicks, and J. Woerner. 2007. Effects 

of Nutrient Enrichment In the Nation’s Estuaries: A Decade of Change. NOAA Coastal Ocean Program 

Decision Analysis Series No. 26. National Centers for Coastal Ocean Science, Silver Spring, MD. 328 pp. 

<http://ccma.nos.noaa.gov/publications/eutroupdate/> Accessed January 2012. 43 TBEP. 2006. Water and sediment quality. In Charting the Course for Tampa Bay. Tampa Bay Estuary 

Program. <http://www.tbep.org/pdfs/ctc/Water%20and%20Sediment%20Quality.pdf> Accessed January 

2012.

44 Caccia, V.G. and J.N. Boyer. 2007. A nutrient loading budget for Biscayne Bay, Florida. Marine 

Pollution Bulletin 54 (2007) 994–1008.

Caccia, V.G. and J.N. Boyer. 2005. Spatial patterning of water quality in Biscayne Bay, Florida as a 

function of land use and water management. Marine Pollution Bulletin 50 (2005) 1416–1429. 45 Caccia, V.G. and J.N. Boyer. 2005. Spatial patterning of water quality in Biscayne Bay, Florida as a 

function of land use and water management. Marine Pollution Bulletin 50 (2005) 1416–1429.
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Page 27 of 191

contributed 88 percent and 66 percent of the Bay’s total dissolved inorganic nitrogen and 

total phosphorus loads, respectively.46

b. Adverse Impacts of Nitrogen and Phosphorus Pollution on Aquatic Life

High nitrogen and phosphorus loadings (or nutrient pollution) to surface and 

groundwaters degrade water quality and negatively impact aquatic life through processes 

associated with eutrophication.47 Eutrophication is a predictable, well understood, and 

widely-documented biological process by which anthropogenic nitrogen and phosphorus 

pollution result in increased growth of harmful algae (plankton and periphyton). 48

 46 Caccia, V.G. and J.N. Boyer. 2007. A nutrient loading budget for Biscayne Bay, Florida. Marine 

Pollution Bulletin 54 (2007) 994–1008. 47 Eutrophication is the process by which a water body becomes enriched with organic material, which is 

formed by primary productivity (i.e., photosynthetic activity) and can be stimulated to harmful levels by the 

anthropogenic introduction of high concentrations of nutrients—particularly nitrogen and phosphorus 

(NRC. 2000. Clean Coastal Waters: Understanding and Reducing the Effects of Nutrient Pollution. 

National Research Council, National Academy of Sciences. See also Nixon 1995. Coastal marine 

eutrophication—A definition, social causes, and future concerns. Ophelia 41:199-219.) 48 Cambridge, M.L., J.R. How, P.S. Lavery, and M.A. Vanderklift. 2007. Retrospective analysis of epiphyte 

assemblages in relation to seagrass loss in a eutrophic coastal embayment. Marine Ecology-Progress Series

346:97-107.

Frankovich, T.A., and J.W. Fourqurean. 1997. Seagrass epiphyte loads along a nutrient availability 

gradient, Florida Bay, USA. Marine Ecology Progress Series159:37-50.

Peterson, B.J., T.A. Frankovich, and J.C. Zieman. 2007. Response of seagrass epiphyte loading to field 

manipulations of fertilization, gastropod grazing and leaf turnover rates. Journal of Experimental Marine 

Biology and Ecology 349(1):61-72.

Howarth, R. D. Anderson, J. Cloern, C. Elfring, C. Hopkinson, B. Lapointe, T. Malone, N. Marcus, K.J. 

McGlathery, A. Sharpley, and D. Walker. 2000. Nutrient pollution of coastal rivers, bays, and seas. Issues 

in Ecology 7:1-15.

Cloern, J.E. 2001. Our evolving conceptual model of the coastal eutrophication problem. Marine Ecology 

Progress Series. 210:223-253. 

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.

Smith, V.H. 2006. Responses of estuarine and coastal marine phytoplankton to nitrogen and phosphorus 

enrichment. 51(1, part 2): 377–384

Vitousek, P.M., J.D. Aber, R.W. Howarth, G.E. Likens, P.A. Matson, D.W. Schindler, W.H. Schlesinger, 

and D.G. Tilman. 1997. Human alteration of the global nitrogen cycle: Sources and consequences. 

Ecological Applications 7(3):737-750. 

Bricker, S.B., J.G. Ferreira, and T. Simas. 2003. An integrated methodology for assessment of estuarine 

trophic status. Ecological Modelling 169(1):39-60.

Bricker, S.B., B. Longstaff, W. Dennison, A. Jones, K. Boicourt, C. Wicks, and J. Woerner. 2008. Effects 

of nutrient enrichment in the nation's estuaries: A decade of change. Harmful Algae 8(1):21-32.

Boyer, J.N., C.R. Kelble, P.B. Ortner, and D.T. Rudnick. 2009. Phytoplankton bloom status: Chlorophyll a
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Increases in algal growth impact many aspects of estuary and coastal 

communities. Increased nutrient loads and excess algal growth create increased oxygen 

demand and may reduce dissolved oxygen concentrations. Increased nutrient 

concentrations also affect algal species composition and competition among species, 

which may lead to increased growth or dominance of toxic or otherwise harmful algal 

species.49 These harmful algal blooms (HABs) can contain undesirable species including 

diatoms, cyanobacteria, and dinoflagellates, which are known to generate toxins that are a 

threat to both aquatic life and recreational activities.50 Many nuisance taxa of algae are 

 biomass as an indicator of water quality condition in the southern estuaries of Florida, USA. Ecological 

Indicators 9(6, Supplement 1):S56-S67.

Hutchinson, G.E. 1961. The paradox of plankton. American Naturalist 95:137-145.

Piehler, M.F., L.J. Twomey, N.S. Hall, and H.W. Paerl. 2004. Impacts of inorganic nutrient enrichment on 

phytoplankton community structure and function in Pamlico Sound, NC, USA. Estuarine Coastal and Shelf 

Science 61(2):197-209.

Sanders, J.G., S.J. Cibik, C.F. D'Elia, and W.R. Boynton. 1987. Nutrient enrichment studies in a coastal 

plain estuary: changes in phytoplankton species composition. Canadian Journal of Fisheries & Aquatic 

Sciences 44:83-90.

Parsons, T.R., P.J. Harrison, and R. Waters. 1978. An experimental simulation of changes in diatom and 

flagellate blooms. Journal of Experimental Marine Biology and Ecology 32:285-294.

Paerl, H.W. 1988. Nuisance phytoplankton blooms in coastal, estuarine, and inland waters. Limnology and 

Oceanography 33(4):823-847.

Harding, J., L.W. 1994. Long-term trends in the distribution of phytoplankton in Chesapeake Bay: roles of 

light, nutrients, and streamflow. Marine Ecology Progress Series 104:267-291.

Richardson, K. 1997. Harmful or Exceptional Phytoplankton Blooms in the Marine Ecosystem. Vol. 31, 

Advances in Marine Biology.

Hagy, J.D., J.C. Kurtz, and R.M. Greene. 2008. An Approach for Developing Numeric Nutrient Criteria for 

a Gulf Coast Estuary. U.S. Environmental Protection Agency, Office of Research and Development, 

National Health and Environmental Effects Research Laboratory, Research Triangle Park, NC., EPA 600R08/004, 44 pp.

49 Paerl 1988. Paerl, H.W. 1988. Nuisance phytoplankton blooms in coastal, estuarine, and inland waters. 

Limnology and Oceanography 33(4):823-847.

Anderson, D.M., P.M. Glibert, and J.M. Burkholder. 2002. Harmful algal blooms and eutrophication: 

Nutrient sources, composition, and consequences. Estuaries 25(4):704-726.

Anderson, D.M., J.M. Burkholder, W.P. Cochlan, P.M. Glibert, C.J. Gobler, C.A. Heil, R.M. Kudela, M.L. 

Parsons, J.E.J. Rensel, D.W. Townsend, V.L. Trainer, and G.A. Vargo. 2008. Harmful algal blooms and 

eutrophication: Examining linkages from selected coastal regions of the United States. Harmful Algae

8(1):39-53. 50 Anderson et al. 2002 Anderson, D.M., P.M. Glibert, and J.M. Burkholder. 2002. Harmful algal blooms 

and eutrophication: Nutrient sources, composition, and consequences. Estuaries 25(4):704-726.

Paerl, H.W. 2002. Connecting atmospheric nitrogen deposition to coastal eutrophication. Environmental 

Science & Technology 36(15):323A-326A.

Anderson, D.M., J.M. Burkholder, W.P. Cochlan, P.M. Glibert, C.J. Gobler, C.A. Heil, R.M. Kudela, M.L. 
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Page 29 of 191

also less palatable to aquatic organisms that consume phytoplankton, which creates a 

food supply impact if prolonged blooms of HABs occur.

Marine and fresh waters of the United States are increasingly being impacted by 

HABs.51 More than 100 HAB species have been identified in the United States.

52 HAB 

toxins have been linked to illnesses and deaths of marine animals, including sea lions, 

turtles, fish, seabirds, dolphins, and manatees.53

Diatoms species in HABs, such as Pseudo-nitzschia, produce domoic acid.

54

Domoic acid has been shown to accumulate in the tissue of mussels, crabs, and fish, 

causing their predators to become ill or die.55 Such toxins occur throughout the United 

States and cause a variety of impacts to aquatic life, including neurological damage and 

death. For example, domoic acid poisoning has been reported as the cause of death of 

humpback whales in the Gulf of Maine in 2003 and sea lions in California's Monterey 

Bay during May and June of 1998.56 Other toxin-producing algal species that have been 

 

Parsons, J.E.J. Rensel, D.W. Townsend, V.L. Trainer, and G.A. Vargo. 2008. Harmful algal blooms and 

eutrophication: Examining linkages from selected coastal regions of the United States. Harmful Algae

8(1):39-53. 51 Dortch, Q. P. Glibert, E. Jewett, and C. Lopez. 2008. Introduction. in HAB RDDTT 2008. National 

Workshop Report. Dortch et al., eds. , Woods Hole, MA.

52 Abbott,G. M., J. H. Landsberg, A. R. Reich, K. A. Steidinger, S.Ketchen, and C. Blackmore. 2009. 

Resource Guide for Public Health Response to Harmful Algal Blooms in Florida. Fish and Wildlife 

Research Institute Technical Report TR-14. viii + 132 p. <http://myfwc.com/research/redtide/taskforce/reports-presentations/resource-guide-for-public-health-response-to-harmful-algal-blooms-in-florida/> 

Accessed June 2011. 53 WHOI. 2008. Marine Mammals. Woods Hole Oceanographic Institution. 

<http://www.whoi.edu/redtide/page.do?pid=14215>. Accessed June 2011.

WHOI. 2008. HAB Impacts on Wildlife. Woods Hole Oceanographic Institution. 

<http://www.whoi.edu/redtide/page.do?pid=9682>. Accessed June 2011.

NOAA. 2011. Overview of Harmful Algal Blooms. National Oceanic and Atmospheric Administration. 

<http://www.cop.noaa.gov/stressors/extremeevents/hab/default.aspx>. Accessed June 2011.

54 Thessen, A.E. and D.K. Stoecker. 2008. Distribution, abundance and domoic acid analysis of the toxic 

diatom genus Pseudo-nitzschia from the Chesapeake Bay. Estuaries and Coasts 31:664-672. 55 Bushaw-Newton, K.L. and K.G. Sellner. 1999. Harmful Algal Blooms. In: NOAA's State of the Coast 

Report. Silver Spring, MD: National Oceanic and Atmospheric Administration. 

<http://oceanservice.noaa.gov/websites/retiredsites/sotc_pdf/hab.pdf>. Accessed June 2011.

56 MBARI. 2000. Molecular Probes Link Sea Lion Deaths to Toxic Algal Bloom. MBARI News. Monterey 
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linked to aquatic life impacts include Pfisteria piscicida, which produces several toxins 

that impact fish and humans57 and the flagellate Heterosigma akashiwo which produces

an ichthyotoxin that kills fish.

58

Secondly, excessive algal growth reduces water clarity, resulting in reduced light

availability for benthic algae, macrophytes, and seagrasses.59 A substantial body of 

scientific research shows that nitrogen and phosphorus pollution plays a significant role 

in the decline of seagrass by reducing light availability. Enhanced nutrient inputs increase 

the phytoplankton biomass and thereby increase water column light attenuation, which 

limits the light available for seagrass photosynthesis. This results in reduced growth and 

increased mortality of seagrasses. In addition, nutrient pollution can lead to excess 

growth of epiphytic algae on seagrasses that blocks the light available to seagrasses and 

affects seagrass growth.60 This reduction of seagrass communities, in turn, results in

 

Bay Aquarium Research Institute. <http://www.mbari.org/news/news_releases/2000/jan06_scholin.html>. 

Accessed June 2011.

57 Waring G.T., E. Josephson, K. Maze-Foley, and P.E. Rosel, eds. 2011. Humpback Whale (Megaptera 

novaeangliae): Gulf of Maine Stock. In U.S. Atlantic and Gulf of Mexico Marine Mammal Stock 

Assessments – 2010, NOAA Technical Memorandum NMFS-NE-219. National Oceanic and Atmospheric 

Administration, National Marine Fisheries Service. < http://www.nefsc.noaa.gov/publications/tm/tm219/>. 

Accessed January 2012.

58 Rensel, J.E.J. 2007. Fish kills from the harmful alga Heterosigma akashiwo in Puget Sound: Recent 

blooms and review. Prepared for National Oceanic and Atmospheric Administration, Center for Sponsored 

Coastal Ocean Research, by Rensel Associates Aquatic Sciences, Arlington, Washington. 

<http://www.whoi.edu/fileserver.do?id=39383&pt=2&p=29109>. Accessed January 2012.

59 Vitousek, P.M., J.D. Aber, R.W. Howarth, G.E. Likens, P.A. Matson, D.W. Schindler, W.H. Schlesinger, 

and D.G. Tilman. 1997. Human alteration of the global nitrogen cycle: Sources and consequences. 

Ecological Applications 7(3):737-750. 

Bricker, S.B., J.G. Ferreira, and T. Simas. 2003. An integrated methodology for assessment of estuarine 

trophic status. Ecological Modelling 169(1):39-60.

Bricker, S.B., B. Longstaff, W. Dennison, A. Jones, K. Boicourt, C. Wicks, and J. Woerner. 2008. Effects 

of nutrient enrichment in the nation's estuaries: A decade of change. Harmful Algae 8(1):21-32.

Boyer, J.N., C.R. Kelble, P.B. Ortner, and D.T. Rudnick. 2009. Phytoplankton bloom status: Chlorophyll a

biomass as an indicator of water quality condition in the southern estuaries of Florida, USA. Ecological 

Indicators 9(6, Supplement 1):S56-S67. 60 Duarte, C.M. 1991. Seagrass depth limits. Aquatic Botany 40(4):363-377.
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impacts such as destabilization of sediments, which causes the release of more nutrients

into the water column.61

The role that nitrogen and phosphorus pollution plays in the decline of seagrass 

has been studied extensively in Florida.62 In a report published by USGS in 2001, six of 

nine Florida estuaries located along the Gulf Coast showed declines in seagrass coverage, 

the predominant causes of which were nitrogen and phosphorus pollution, dredging, 

propeller scarring, hydrologic alterations, increased turbidity, and chronic light 

reduction.63 Florida Fish & Wildlife Conservation Commission has noted several areas of 

significant seagrass decline between 1950 and 2000, including 72 percent loss in St 

Joseph Sound, 43 percent loss in the northern section of Biscayne Bay near Miami, 40

percent loss in Tampa Bay, 30 percent loss in the Indian River Lagoon, and 29 percent

loss in Charlotte Harbor. These losses were associated with population growth in these 

watersheds that occurred during the same time period, indicating impacts from human 

activities such as runoff from residential and agricultural areas containing fertilizers and 

 61 Boyer, J.N., C.R. Kelble, P.B. Ortner, and D.T. Rudnick. 2009. Phytoplankton bloom status: Chlorophyll 

a biomass as an indicator of water quality condition in the southern estuaries of Florida, USA. Ecological 

Indicators 9(6, Supplement 1):S56-S67. 62 For more information refer to: (1) Dawes, C.J., R.C. Phillips, and G. Morrison. 2004. Seagrass 

Communities of the Gulf Coast of Florida: Status and Ecology. Florida Fish and Wildlife Conservation 

Commission Fish and Wildlife Research Institute and the Tampa Bay Estuary Program. St. Petersburg, FL. 

iv + 74 pp.; (2) Tomasko, D.A., C.A. Corbett, H.S. Greening, and G.E. Raulerson. 2005. Spatial and 

temporal variation in seagrass coverage in Southwest Florida: assessing the relative effects of 

anthropogenic nutrient load reductions and rainfall in four contiguous estuaries. Marine Pollution Bulletin

50: 797–805.; (3) Orth, R.J., T.J.B. Carruthers, W.C. Dennison, C.M. Duarte, J.W. Fourqurean, K.L. Heck 

Jr., A.R. Hughes, G.A. Kendrick, W.J. Kenworthy, S. Olyarnik, F.T. Short, M. Waycott, and S.L. Williams. 

2006. A global crisis for seagrass ecosystems. Bioscience 56:987-996.; (4) Burkholder, J.M., D.A. 

Tomasko, and B.W. Touchette. 2007. Seagrasses and eutrophication. Journal of Experimental Marine 

Biology and Ecology 350:46-72.; (5) Collado-Vides, L., V.G., Caccia, J.N. Boyer, and J.W. Fourqurean. 

2007. Tropical seagrass-associated macroalgae distributions and trends relative to water quality. Estuarine, 

Coastal and Shelf Science 73:680-694. 63 USGS. 2001. Seagrass Habitat In the Northern Gulf of Mexico: Degradation, Conservation,

and Restoration of a Valuable Resource. USGS Gulf of Mexico Habitat Program Team,

855-R-04-001. <http://gulfsci.usgs.gov/gom_ims/pdf/pubs_gom.pdf>. Accessed July 2011.
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construction projects which contribute high levels of suspended sediments.64 Several 

studies have attributed declines in seagrass to excess chlorophyll a and phytoplankton in 

the water column which can increase light attenuation. One study conducted from 1989-

1991 found that excess chlorophyll a caused light attenuation of 16 to 28 percent across 

Charlotte Harbor and Tampa Bay. However, the authors did note an overall improvement 

in seagrass recolonization and areal cover in Hillsborough Bay and other parts of Tampa 

Bay starting in the late 1980s coinciding with increased water clarity.65 A later study, 

which conducted sampling monthly between June 1998 and July 1999, estimated that 

phytoplankton biomass contributed approximately 29 percent of total water column light 

attenuation in Lemon Bay, Florida. The authors predicted a continuation in the potential 

decline of seagrasses with increased urbanization. 66

Lastly, excessive algal growth also leads to low dissolved oxygen (DO)

potentially creating hypoxic and anoxic conditions.

67 The cause and effect relationship 

between nitrogen and phosphorus pollution and marine hypoxia is clear and well 

documented in the scientific literature.

68 Increased nitrogen and phosphorus inputs lead to 

 64 FWCC. 2002. Florida’s Seagrass Meadows: Benefitting Everyone. Florida Fish & Wildlife Conservation 

Commission. <http://www.sarasotabay.org/documents/seagrassbrochure.pdf>. Accessed July 2011. 65 McPherson, B.F., and R.L. Miller. 1994. Causes of Light Attenuation in Tampa Bay and Charlotte 

Harbor, Southwestern Florida. Water Resources Bulletin 30(1):43-53. 66 Tomasko, D.A., D.L. Bristol, and J.A. Ott. 2001. Assessment of present and future nitrogen loads, water 

quality, and seagrass (Thalassia testudinum) depth distribution in Lemon Bay, Florida. Estuaries

24(6A):926-938. 67 Vitousek, P.M., J.D. Aber, R.W. Howarth, G.E. Likens, P.A. Matson, D.W. Schindler, W.H. Schlesinger, 

and D.G. Tilman. 1997. Human alteration of the global nitrogen cycle: Sources and consequences. 

Ecological Applications 7(3):737-750. 68 Conley, D., J. Carstensen, R. Vaquer-Sunyer, and C. Duarte. 2009. Ecosystem thresholds with hypoxia. 

Hydrobiologia 629(1):21-29. 

Conley, D.J., H.W. Paerl, R.W. Howarth, D.F. Boesch, S.P. Seitzinger, K.E. Havens, C. Lancelot, and G.E. 

Likens. 2009. ECOLOGY Controlling Eutrophication: Nitrogen and Phosphorus. Science 323(5917):1014-

1015. 

Conley, D.J., H.W. Paerl, R.W. Howarth, D.F. Boesch, S.P. Seitzinger, K.E. Havens, C. Lancelot, and G.E. 

Likens. 2009. Eutrophication: Time to Adjust Expectations Response. Science 324(5928):724-725. 
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excessive algal growth and organic matter loading to bottom waters. Bacterial

decomposition of the organic matter consumes oxygen and depletes the water column of 

DO.69 In estuaries and coastal waters, low DO is one of the most widely reported 

consequences of nitrogen and phosphorus pollution and one of the best predictors of a 

range of biotic impairments.70 Low DO causes impacts to aquatic life ranging from 

mortality to chronic impairment of growth and reproduction.71 Hypoxia is typically 

defined as DO < 2 mg/L, and anoxia as DO < 0.1 mg/L.72 When nutrient pollution creates 

conditions that result in large hypoxic zones, substantial changes in fish, benthic, and 

plankton communities may occur. 73 This includes avoidance behaviors by fish, mobile 

benthic invertebrates migrating from the hypoxic area, and fish kills in some systems 

when fish and other mobile aquatic organisms have nowhere to migrate away from the 

areas with low DO. 74 This can result in changes to the benthic invertebrate community 

 

Diaz, R.J. 2001. Overview of hypoxia around the world. Journal of Environmental Quality 30(2):275-281. 

Diaz, R.J. and R. Rosenberg. 2008. Spreading dead zones and consequences for marine ecosystems. 

Science 321(5891):926-929. 69 Clement, C.,, S. B. Bricker and D.E. Pirhalla. 2001 (on-line). Eutrophic Conditions in Estuarine Waters. 

In: NOAA's State of the Coast Report. Silver Spring, MD: National Oceanic and Atmospheric 

Administration. URL: http://state-of-coast.noaa.gov/bulletins/html/eut_18/eut.html. Accessed December 

2011.

70 Bricker, S.B., J.G. Ferreira, and T. Simas. 2003. An integrated methodology for assessment of estuarine 

trophic status. Ecological Modelling 169(1):39-60.

Bricker, S.B., C.G. Clement, D.E. Pirhalla, S.P. Orlando, and D.R.G. Farrow. 1999. National Estuarine 

Eutrophication Assessment, Effects of Nutrient Enrichment in the Nation's Estuaries. NOAA, National 

Ocean Service, Special Projects Office and the National Centers for Coastal Ocean Science. Silver Spring, 

MD.

71 USEPA. 2001. Nutrient Criteria Technical Guidance Manual, Estuarine and Coastal Marine Waters. 

EPA-822-B-01-003. USEPA, Office of Water, Office of Science and Technology. 72 USEPA. 1999. Ecological Conditions of Estuaries in the Gulf of Mexico. EPA 620-R-98-004. U.S. 

Environmental Protection Agency, Office of Research and Development, National Health and 

Environmental Effects Research Laboratory, Gulf Ecology Division, Gulf Breeze, Florida.

73 Howell, P. and D. Simpson. 1994. Abundance of marine resources in relation to dissolved oxygen in 

Long Island Sound. Estuaries 17(2):394-402. 

Kidwell, D.M., A.J. Lewitus, S. Brandt, E.B. Jewett, and D.M. Mason. 2009. Ecological impacts of 

hypoxia on living resources. Journal of Experimental Marine Biology and Ecology 381(Supplement 1):S1-

S3. 

74 Howell, P. and D. Simpson. 1994. Abundance of marine resources in relation to dissolved oxygen in 

Long Island Sound. Estuaries 17(2):394-402
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structure of estuaries and coastal areas, with increases of organisms more tolerant of low 

DO.

75 Even intermittent hypoxia can cause shifts in the benthic assemblage to favor 

resistant or tolerant organisms, which are less desirable food sources, creating unbalanced 

benthic communities in the hypoxic zone because fish avoid the area.76 When hypoxia 

extends into shallow waters, it affects spawning and nursery areas for many important 

fish species by reducing the habitat available that protects smaller fish and aquatic 

organisms, especially juveniles, from predation.77 Hypoxia has been implicated in a

recent increase and late-summer dominance of hypoxia-tolerant gelatinous zooplankton 

(jellyfish and ctenophores) in the Chesapeake Bay and other eastern estuaries.78 Reduced 

fishery production in hypoxic zones has been documented in the United States and 

worldwide.79

Hypoxia and anoxia in bottom waters result in anoxia in the surface sediments, 

which has geochemical consequences including acidification, release of toxic hydrogen 

 Kidwell, D.M., A.J. Lewitus, S. Brandt, E.B. Jewett, and D.M. Mason. 2009. Ecological impacts of 

hypoxia on living resources. Journal of Experimental Marine Biology and Ecology 381(Supplement 1):S1-

S3.) 75 Baker, S. and R. Mann. 1992. Effects of hypoxia and anoxia on larval settlement, juvenile growth, and 

juvenile survival of the oyster Crassostrea virginica. Biological Bulletin 182(2):265-269. 

Baker, S. and R. Mann. 1994. Feeding ability during settlement and metamorphosis in the oyster 

Crassostrea virginica (Gmelin, 1791) and the effects of hypoxia on post-settlement ingestion rates. Journal 

of Experimental Marine Biology and Ecology 181(2):239-253. 

Baker, S.M. and R. Mann. 1994. Description of metamorphic phases in the oyster Crassostrea virginica

and effects of hypoxia on metamorphosis. Marine Ecology Progress Series 104:91-99. 

Baustian, M. and N. Rabalais. 2009. Seasonal composition of Benthic Macroinfauna exposed to hypoxia in 

the northern Gulf of Mexico. Estuaries and Coasts 32(5):975-983. 

Breitburg, D. 2002. Effects of hypoxia, and the balance between hypoxia and enrichment, on coastal fishes 

and fisheries. Estuaries 25(4):767-781. 76 Kidwell, D.M., A.J. Lewitus, S. Brandt, E.B. Jewett, and D.M. Mason. 2009. Ecological impacts of 

hypoxia on living resources. Journal of Experimental Marine Biology and Ecology 381(Supplement 1):S1-

S3.

77 Breitburg, D. 2002. Effects of hypoxia, and the balance between hypoxia and enrichment, on coastal 

fishes and fisheries. Estuaries 25(4):767-781. 78 Grove, M. and D.L. Breitburg. 2005. Growth and reproduction of gelatinous zooplankton exposed to low 

dissolved oxygen. MARINE ECOLOGY PROGRESS SERIES 301 185–198. 79 Diaz, R.J. and R. Rosenberg. 2008. Spreading dead zones and consequences for marine ecosystems. 

Science 321(5891):926-929.
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sulfide, soluble reactive phosphorus, and ammonia.80 The sediment of hypoxic zones then 

becomes a potential source of nutrients that can increase the degree of eutrophication.

Systems that have had persistent and chronic hypoxia often fail to recover quickly even 

after pollution loadings have been reduced.81 Reduced oxygen also affects a variety of 

other biogeochemical processes that can impact water quality, such as the chemical form 

of metals in the water column.82 

Florida has been impacted by algal blooms for many years. Red algae, Laurencia 

intricata and Spyridia filamentosa; brown algae, Dictyota sp. and Sargassum filipendula; 

and green algae, Enteromorpha sp., Codium isthmocladum, and Halimeda sp. grow in the 

Florida Bay area.83 That growth has threatened the commercially important fish, lobster, 

and shrimp nurseries in the area.84 Southern Palm Beach and northern Broward counties 

have been impacted by algal mats made up of Caulerpa species since the 1990s.85

 80 Diaz, R.J. and R. Rosenberg. 2008. Spreading dead zones and consequences for marine ecosystems. 

Science 321(5891):926-929.

Kemp, W.M., W.R. Boynton, J.E. Adolf, D.F. Boesch, W.C. Boicourt, G. Brush, J.C. Cornwell, T.R. 

Fisher, P.M. Glibert, J.D. Hagy, L.W. Harding, E.D. Houde, D.G. Kimmel, W.D. Miller, R.I.E. Newell, 

M.R. Roman, E.M. Smith, and J.C. Stevenson. 2005. Eutrophication of Chesapeake Bay: Historical trends 

and ecological interactions. Marine Ecology Progress Series 303:1-29.

McCarthy, M., K. McNeal, J. Morse, and W. Gardner. 2008. Bottom-water hypoxia effects on sediment–

water interface nitrogen transformations in a seasonally hypoxic, shallow bay (Corpus Christi Bay, TX, 

USA). Estuaries and Coasts 31(3):521-531.

Cai et al. 2011 Acidification of subsurface coastal waters enhanced by eutrophication. Nature Geoscience

4:766–770. 81 Conley, D.J., J. Carstensen, G. Ærtebjerg, P.B. Christensen, T. Dalsgaard, J.L.S. Hansen, and A.B. 

Josefson. 2007. Long-term changes and impacts of hypoxia in Danish coastal water. Ecological 

Applications 17(sp5):S165-S184.

Diaz, R.J. and R. Rosenberg. 2008. Spreading dead zones and consequences for marine ecosystems. 

Science 321(5891):926-929. 82 Snoeyink, V.L. and D. Jenkins. 1980. Water Chemistry. John Wiley and Sons, New York. 83 Anderson, D.M., ed. 1995. ECOHAB, The Ecology and Oceanography of Harmful Algal Blooms: A 

National Research Agenda. Woods Hole Oceanographic Institution, Woods Hole, MA.

84 Anderson, D.M., ed. 1995. ECOHAB, The Ecology and Oceanography of Harmful Algal Blooms: A 

National Research Agenda. Woods Hole Oceanographic Institution, Woods Hole, MA. 85 Jacoby, C., B. Lapointe, and L. Creswell. No date. Are alternative and nonindigenous seaweeds 

overgrowing Florida’s east coast reefs? SGEF–156. Florida Sea Grant College Program. 

<http://nsgl.gso.uri.edu/flsgp/flsgpg01015.pdf>. Accessed January 2012.
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Gambierdiscus toxicus (a ciguatoxin producer) is found from Palm Beach to the Dry 

Tortugas and Florida Bay and is suspected to have caused fish kills and disease events.

86

Large floating mats of Lyngbya majuscula were common across Charlotte Harbor, Cedar 

Key, Sebastian Inlet, Sarasota Bay, Tampa Bay, Terra Ceia Bay, Palma Sola, Manatee 

River, and northwest Bradenton in 1999, 2000, and 2002.87 Aureoumbra lagunensis

(Texas brown tide) was found in low abundance (< 200 cells/mL) at stations in Florida 

Bay from November 1996 to June 1997.88 In 1991, widespread and persistent blooms of 

cyanobacteria in Florida Bay coincided with massive sponge die-offs, which impacted the 

behavior and abundance of populations of juvenile Caribbean spiny lobsters.89 Two 

Pseudo-nitzschia species found in Florida are P. calliantha, which was observed at bloom 

levels in the northern Indian River Lagoon, and P. pseudodelicatissima.

90 Pseudonitzschia spp. has been observed in Tampa Bay since the 1960s.91

 86 FFWCC. No date. Gambierdiscus toxicus. Florida Fish and Wildlife Conservation Commission. 

<http://myfwc.com/media/202186/g_toxicus_1054.pdf>. Accessed January 2012.

87 FFWCC. No date. Blue-Green Algal Blooms in Coastal Florida; 1999, 2000, and 2002. Florida Fish and 

Wildlife Conservation Commission. < http://myfwc.com/research/redtide/archive/historical-events/bluegreen-algal-blooms-coastal-fl/>. Accessed January 2012. 88 Muhlstein, H.I., and T.A. Villareal. 2007. Organic and inorganic nutrient effects on growth rate 

irradiance relationships in the Texas brown-tide alga Aureoumbra lagunensis (Pelagophyceae). Journal of 

Phycology 43(6):1223-1226.

Villareal, T.A., Chirichella, T., Buskey, E.J. 2004. Regional Distribution of the Texas Brown Tide 

(Aureoumbra lagunensis) in the Gulf of Mexico. In Harmful Algae 2002, ed. K.A. Steidinger, J.H. 

Landsberg, C.R. Tomas, and G.A. Vargo, pp. 374-376. Florida Fish and Wildlife Conservation 

Commission, Florida Institute of Oceanography, and Intergovernmental Oceanographic Commission of 

UNESCO, St. Petersburg, Florida. <http://myfwc.com/research/redtide/information/links/x-internationalconference/>. Accessed January 2012.

89 Butler, M.J,, J.H. Hunt, W.F. Herrnking, M.J. Childress, R. Bertelsen, W. Sharp, T. Matthews, J.M.

Field, and H.G. Marshall. 1995. Cascading disturbances in Florida Bay, USA: cyanobacteria blooms, 

sponge mortality, and implications for juvenile spiny lobsters Panulirus argus. Marine Ecology Progress 

Series 129:119-125.

90 Phlips et al. 2011. Scales of temporal and spatial variability in the distribution of harmful algae species in 

the Indian River Lagoon, Florida, USA. Harmful Algae 10:277-290.

Phlips, E.J., S. Badylak, S. Youn, and K. Kelley. 2004. The occurrence of potentially toxic dinoflagellates 

and diatoms in a subtropical lagoon, the Indian River Lagoon, Florida, USA. Harmful Algae 3(1):39-49.

91 Badylak, S., E.J. Phlips, P. Baker, J.Fajans, and R. Boler. 2007. Distributions of phytoplankton in Tampa 

Bay estuary, U.S.A. 2002-2003. Bulletin of Marine Science 80(2):295-317.
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In addition to being impacted by algal toxins and decline of seagrass, aquatic life 

in Florida is directly impacted by hypoxia. In June 2011, a fish kill in Marco Islands,

Florida was attributed to low dissolved oxygen, resulting from a “mixed” bloom of nontoxic algae and diatoms.92 Scientists at the University of Texas showed that chronic 

exposure of Atlantic croaker to hypoxia in Florida’s East Bay estuary resulted in “marked 

suppression of ovarian and testicular growth which was accompanied by endocrine 

disruption.” During the same study, the scientists observed normal gonadal growth in 

Atlantic croaker found in the nearby waters of Pensacola Bay which had sufficient 

oxygen levels.93

Newspapers in Florida regularly report on impacts associated with nitrogen and 

phosphorus pollution. Recent examples include reports of algal blooms and fish kills in 

the St. Johns River.

94 Spring releases of water from Lake Okeechobee into the St. Lucie 

Canal resulted in floating mats of toxic cyanobacteria, Microcystis aeruginosa, prompting 

Martin and St. Lucie county health departments to issue public health warnings.95 A large 

Microcystis bloom was documented in the Lower St. Johns River in 2005, covering a 100

 92 Fish kill in island canals appears over. 2011. Marconews.com –Marco Eagle. 

<http://www.marconews.com/news/2011/jun/02/dead-fish-bad-smell-permeate-parts-island/?print=1>. 

Accessed January 2012.

93 Thomas, P., Md. S. Rahman, I.A. Khan, and J.A. Kummer. 2007. Widespread endocrine disruption and 

reproductive impairment in an estuarine fish population exposed to seasonal hypoxia. Proceedings of the 

Royal Society B (274):2693–2701.

94 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. 

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-environmentalquestions>. Accessed October 2010.

95 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-algaefound-floating-near-palm-city-o/>. Accessed October 2010.
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mi (160 km) stretch from Jacksonville to Crescent City.96 Toxic cyanobacteria Anabaena 

circinalis and Cylindrospermopsis raciborskii have been implicated in fish kills in the 

Lower St. Johns River basin.97 In addition, in June 2009, a large algal bloom stretching 

more than 14 mi (23 km) was documented in Tampa Bay. This was linked to surface 

water runoff of nutrients and pollutants (e.g., fertilizers, yard waste, animal feces) that 

were washed into the bay from recent heavy rains.98

Numerous algal blooms, some capable of producing toxins, foul odors, and fish 

kills, occurred in Florida coastal areas, estuaries, and canals in 2011. Green algae, known 

as June Grass, were found washing onto local beaches on Okaloosa Island. The algae 

adheres to swimmers, covers beaches and hinders fishing.99

In the Caloosahatchee River and estuary, high algae and salinity levels caused the 

Olga water treatment plant in Lee County to close in May 2011. Customers complained 

about unusual tastes and odors in their drinking water. The blue-green algae bloom 

significantly affected areas from the W.P. Franklin Lock and Dam, upstream through 

Alva and LaBelle, Florida. The bloom caused fish, bird and shellfish mortalities, and 

triggered the Lee County Health Department to issue warnings and advisories on water 

 96 Aubel, M., P. D'Aiuto, A. Chapman, D. Casamatta, A. Reich, S. Ketchen, and C. Williams. 2006. BlueGreen Algae in St. Johns River, FL. Lakeline Summer 2006: 40-45. 97 FWRI. 2009. Resource Guide for Public Health Response to Harmful Algal Blooms in Florida. ed. G. M. 

Abbott, J. H. Landsberg, A. R. Reich, K. A. Steidinger, S. Ketchen and C. Blackmore. Technical Report 

TR-14. Florida Fish and Wildlife Research Institute. 

<http://www.lsjr.org/pdf/ResourceGuide_FL_algal_blooms_2009.pdf>. Accessed June 2011.

98 Pittman, C. 2009. Algae bloom one of largest in Tampa Bay history. St. Petersburg Times. 

<http://www.tampabay.com/news/environment/water/article1013322.ece>. Accessed July 2010. 99 Tammen, K. 2011, April 20. It’s not even June and the June Grass is Back. Northwest Florida Daily 

News. http://www.nwfdailynews.com/news/grass-39438-island-okaloosa.html. Accessed April 2011.
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and fish consumption as well as swimming. Toxic blue-green algae species were 

identified in the bloom, including Anabaena, Oscillatoria and Aphanizomenon sp.100

The Indian River Lagoon also experienced large and prolonged algae blooms.

High levels of green algae Resultor sp. were found from Titusville to Melbourne and 

covering the entire Banana River. The algae were thought to be responsible for killing 

hundreds of fish and inhibiting seagrass growth.101 A large rust-colored bloom of 

Pyrodinium bahamense formed in Old Tampa Bay in August 2011; the bloom stretched 

from Safety Harbor to the Howard Frankland Bridge and was thought to be caused by a 

combination of heat, rain, and fertilizer runoff.102

c. Adverse Impacts of Nitrogen and Phosphorus Pollution on Human Health

 100 Lee Closes a Water Plant; Blame Algae and Saltwater intrusion in Caloosahatchee. 2011, May 19. CBS 

Wink News Now. http://www.winknews.com/Local-Florida/2011-05-19/Lee-Closes-a-Water-Plant-BlameAlgae-and-Salt-water-intrusion-in-Caloosahatchee. Accessed December 2011.

Lollar, K. 2011, June 6. Bacterial bloom stains waterway up to LaBelle. News-Press.

http://www.marconews.com/news/2011/jun/02/dead-fish-bad-smell-permeate-parts-island/. Accessed June 

2011.

Crisis in the Caloosahatchee: Algal blooms in local waters. 2011, June 8. Sanibel-Captiva Islander. 

http://sanibel-captiva-islander.com/page/content.detail/id/511872/Crisis-in-the-Caloosahatchee--Algalblooms-in-local-waters.html?nav=5051. Accessed June 2011.

Warning added for Lee County waters. 2011, June 16. CBS Wink News Now.

http://www.winknews.com/Local-Florida/2011-06-16/Warning-added-for-Lee-County-waters. Accessed 

June 2011.

Cornwell, B. 2011, June 22. Algae Bloom doesn’t deter everyone. Fort Meyers Florida Weekly. 

http://fortmyers.floridaweekly.com/news/2011-06-

22/Top_News/Algae_bloom_doesnt_deter_everyone.html. Accessed June 2011. 101 Florida Today. 2011, July 18. Green algae killing fish, seagrass in northern Indian River Lagoon. 10 

News WTSP – Tampa Bay. http://www.wtsp.com/rss/article/201465/19/Green-algae-killing-fish-seagrassin-northern-Indian-River-Lagoon. Accessed December 2011. 102 Reyes, R. 2011, August 31. Algae bloom continues to grow in Old Tampa Bay. Tampa Bay Online.

http://www2.tbo.com/news/breaking-news/2011/aug/31/1/algae-bloom-continues-to-grow-in-old-tampabay-ar-254281/. Accessed December 2011.

Harwell, D. 2011, August 27. Tampa Bay algae bloom threatens the estuary’s fish. St. Petersburg Times.

http://www.tampabay.com/news/environment/water/tampa-bay-algae-bloom-threatens-the-estuarysfish/1188284. Accessed August 2011.
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Toxins produced by HABs have been linked, through recreational exposure, to 

adverse human health impacts through ingestion of contaminated seafood, dermal 

reactions, and respiratory problems.103 Ingestion of seafood that is contaminated with 

toxins causes gastrointestinal, neurological, cardiovascular, and hepatological illnesses. 

In some severe cases, ingestion of even a small amount of contaminated seafood can 

result in coma or death.104 Each year in the United States, incidents of poisoning from 

marine toxins are reported to the CDC.105

Among the toxins HABs produce are ciguatoxins, which leads to Ciguatera fish 

poisoning (CFP), one of the most commonly reported food borne illnesses caused by a 

marine biotoxin in the United States,106 with 176 cases reported in 2009 (22 percent of 

the total reported cases of food poisoning from seafood toxins).

107 Ciguatoxins are 

 103 WHOI. 2006. Harmful Algae and Red Tides Primer. Woods Hole Oceanographic Institute, Woods Hole, 

MA.

Anderson, D. 2004. The growing problem of Harmful Algae. Woods Hole Oceanographic Institute, Woods 

Hole, MA.

Graham, J. 2007. Harmful Algal Blooms. U.S. Geological Survey, Lawrence, KS

CDC. 2004. About Harmful Algal Blooms. Centers for Disease Control and Prevention, Atlanta, GA

Bronstein, A.C., D.A. Spyker, L.R. Cantilena, Jr., J.L. Green, B.H. Rumack, S.L. Giffin. 2009. 2008 

Annual Report of the American Association of Poison Control Centers’ National Poison Data System 

(NPDS): 26th Annual Report. Clinical Toxicology 48:979–1178.

Landsberg, J., F.Van Dolah, and G. Doucette. 2006. Marine and estuarine harmful algal blooms: Impacts 

on human and animal health. In Oceans and Health: Pathogens in the Marine Environment. Edited by 

Belkin and Colwell, Springer, New York, 2005.

NOAA. 2009. Marine Biotoxins. National Oceanic and Atmospheric Administration. 

<http://www.nwfsc.noaa.gov/hab/habs_toxins/marine_biotoxins/index.html>. Accessed December 2011.

Anderson, D. P. Glibert, and J. Burkholder. (DATE) Harmful Algal Blooms and Eutrophication: Nutrient 

Sources, Composition, and Consequences. Estuaries 25(4b): 704-726. 104 Bushaw-Newton, K.L. and K.G. Sellner 1999. Harmful Algal Blooms. In: NOAA's State of the Coast 

Report. Silver Spring, MD: National Oceanic and Atmospheric Administration. 

<http://oceanservice.noaa.gov/websites/retiredsites/sotc_pdf/hab.pdf> 105 CDC. 2005. Marine Toxins: Frequently Asked Questions. Centers for Disease Control and Prevention. <

http://www.cdc.gov/ncidod/dbmd/diseaseinfo/marinetoxins_g.htm> Accessed June 2011. 106 Dickey, R.W., and S.M. Plakas. 2010. Ciguatera: A public health perspective. Toxicon 56: 123-136. 107 Bronstein, A.C., D.A. Spyker, L.R. Cantilena, Jr., J.L. Green, B.H. Rumack, S.L. Giffin. 2009. 2008 

Annual Report of the American Association of Poison Control Centers’ National Poison Data System 

(NPDS): 26th Annual Report. Clinical Toxicology 48:979–1178.
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bioaccumulative, causing gastrointestinal, neurological, or cardiovascular symptoms that 

vary in intensity.108

Saxitoxins are also produced by HABs, leading to paralytic shellfish poisoning 

(PSP, which occurs when humans eat shellfish contaminated with saxitoxins, affecting

the nervous system and in severe cases causing respiratory paralysis.109 Domoic acid, 

also produced by HABs, can also cause food poisoning, producing symptoms ranging

from mild gastrointestinal discomfort to permanent brain damage and, in rare cases,

death.110 Recreational exposure to toxins from HABs occur when humans inhale sea 

spray vapor containing fragments of marine algae cells and their associated toxins during

water-related activities such as jet-skiing or boating, causing hay fever-like respiratory 

problems.

111

In addition, elevated levels of nitrate, a byproduct of nutrient pollution in surface 

waters, can cause public health concerns if the water is a drinking water source, where 112

nitrate is converted to harmful nitrite after ingestion.113 The primary human health 

concern with nitrates and nitrites in drinking water is methemoglobinemia, although 

 108 McKee D. Physician diagnosis and reporting of ciguatera fish poisoning in an endemic area. In Harmful 

Algal Blooms 2000, eds. G.M. Hallegraeff, S.I. Blackburn, C.J. Bolch, and R.J. Lewis. Proceedings of the 

9th International Conference on Harmful Algal Blooms, Intergovernmental Oceanographic Commission of 

UNESCO: Paris.

109 Landsberg, J., F.Van Dolah, and G. Doucette. 2006. Marine and estuarine harmful algal blooms: 

Impacts on human and animal health. In Oceans and Health: Pathogens in the Marine Environment. Edited 

by Belkin and Colwell, Springer, New York, 2005.

110 NOAA. 2009. Marine Biotoxins. National Oceanic and Atmospheric Administration. 

<http://www.nwfsc.noaa.gov/hab/habs_toxins/marine_biotoxins/index.html>. Accessed December 2011. 111 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. 112 FDEP. 1998. WaterGroundwater 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.

113 Gulis. G., M. Czompolyova, J.R. Cerhan. 2002. An Ecologic Study of Nitrate in Municipal Drinking 

Water and Cancer Incidence in Trnava District, Slovakia. Environmental Research 88:182–187.
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adverse thyroid effects have been associated with elevated nitrates as well.

114

Methemoglobinemia, or “blue baby syndrome,” as the name implies, most often affects 

infants less than six months old, although adults can also be affected when the ingested

nitrate is converted to nitrite in the body that prevents hemoglobin in the blood from 

delivering oxygen effectively throughout the body. Methemoglobinemia is an acute 

disease and symptoms can develop rapidly in infants, usually over a period of days.

Symptoms include shortness of breath and blueness of the skin, and even death in severe 

cases. 115

EPA developed a Maximum Contaminant Level (MCL) of 10 mg/L for nitrate in 

drinking water and an MCL of 1 mg/L for nitrite.116 In the 2010 USGS National WaterQuality Assessment Program report, nitrate concentrations in streams across the U.S. 

exceeded 10 mg/L in 28 percent of streams in agricultural areas and 83 percent of studies 

of shallow ground water. However, the report also found that nitrate concentrations 

exceeding the MCL of 10 mg/L were more prevalent in groundwater drinking water 

sources than in streams.117 There is strong documentation for the increased contamination 

 114.Fan, A.M. and Steinberg, V.E. (1996). Health implications of nitrate and nitrite in drinking water: an 

update on methemoglobinemia occurrence and reproductive and development toxicity. Regul. Toxicol. 

Pharmacol., 23(1 Pt 1): 35–43. 115 Manassaram, D. M., L. C. Backer, and D. 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.

FDEP. 2011. Drinking Water: Inorganic Contaminants. Florida Department of Environmental Protection. 

<http://www.dep.state.fl.us/water/drinkingwater/inorg_con.htm>. Accessed November 2011. 116 USEPA. 2007. Nitrates and Nitrites: TEACH Chemical Summary. U.S. Environmental Protection

Agency. <http://www.epa.gov/teach/chem_summ/Nitrates_summary.pdf>. Accessed November 2011. 117 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. 

http://water.usgs.gov/nawqa/nutrients/pubs/circ1350. Accessed November 2011.
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of groundwater aquifers and drinking water supplies from anthropogenic sources of 

nitrogen.118

Nitrate is the most common nutrient found in groundwater. Elevated nitrate 

concentrations in groundwater are more common in rural agricultural areas that are often 

served by private wells. When nitrate occurs at concentrations greater than 1 mg/L, it is

considered to be the result of human activities such as application of agricultural 

fertilizers, disposal of animal wastes, and use of septic tanks.119

Nitrogen and phosphorus pollution has been clearly linked to human health

impacts in Florida, primarily through illnesses associated with HABs. Significant HABcaused toxins that have been found in Florida’s marine waters include saxitoxins, 

brevetoxins, ciguatoxins, cyanotoxins, domoic acid, and okadaic acid.120

Between January 2002 and May 2004, 28 cases of saxitoxin poisoning associated 

with puffer fish caught in Florida’s Indian River Lagoon (IRL) were reported. In 2002, 

Florida Fish and Wildlife Conservation Commission banned the commercial and 

recreational harvest of puffer fish in several water bodies in Florida and made that ban 

 118 USGS. 2010. Hydrogeology and Groundwater Quality of Highlands County, FL. Scientific 

Investigations Report 2010–5097. U.S. Geological Survey, Reston, VA

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.

119 DeSimone, L. et al. 2009. Quality of Water from Domestic Wells in Principal Aquifers of the United 

States, 1991-2004: Overview of Major Findings. United States Geological Survey. National Water Quality 

Assessment Program. Circular 1332.

http://water.usgs.gov/nawqa/studies/domestic_wells/WaterWellJournalArticle_DeSimoneetal2009.pdf. 

Accessed November 2011.

120 Abbott,G. M., J. H. Landsberg, A. R. Reich, K. A. Steidinger, S.Ketchen, and C. Blackmore. 2009. 

Resource Guide for Public Health Response to Harmful Algal Blooms in Florida. Fish and Wildlife 

Research Institute Technical Report TR-14. viii + 132 p. <http://myfwc.com/research/redtide/taskforce/reports-presentations/resource-guide-for-public-health-response-to-harmful-algal-blooms-in-florida/> 

Accessed June 2011
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permanent in 2004.121 Although puffer fish poisoning is typically associated with 

tetrodotoxins, samples were also contaminated with saxitoxins.122

In Florida, ciguatera fish poisoning (CFP) poses a significant risk to public 

health.123 One estimate indicates that approximately 1,300 cases of CFP (reported and 

unreported cases) occur annually in Florida.124 The Florida Department of Health 

(FDOH) reported 8 cases of CFP in 2005, 44 cases in 2006, 34 cases in 2007, and 51 

cases in 2008.125

d. Adverse Impacts of Nitrogen and Phosphorus Pollution on the Economy

Excessive algal blooms result in a range of economic losses, including lost 

revenue from impacts to commercial fisheries, recreational fishing and boating trips, and 

tourism, as well as increased drinking water costs and reduced waterfront property 

 121 Abbott,G. M., J. H. Landsberg, A. R. Reich, K. A. Steidinger, S.Ketchen, and C. Blackmore. 2009. 

Resource Guide for Public Health Response to Harmful Algal Blooms in Florida. Fish and Wildlife 

Research Institute Technical Report TR-14. viii + 132 p. <http://myfwc.com/research/redtide/taskforce/reports-presentations/resource-guide-for-public-health-response-to-harmful-algal-blooms-in-florida/> 

Accessed June 2011.

122 Landsberg, J.H., S. Hall, J.N. Johannessen, K.D. White, S.M. Conrad, J.P. Abbott, L.J. Flewelling, R.W. 

Richardson, R.W. Dickey, E.L.E. Jester, S. M. Etheridge, J.R. Deeds, F.M. Van Dolah, T.A. Leighfield, Y. 

Zou, C.G. Beaudry, R.A. Benner, P.L. Rogers, P.S. Scott, K. Kawabata, J.L. Wolny, and K.A. Steidinger. 

2006. Saxitoxin Puffer Fish Poisoning in the United States, with the First Report of Pyrodinium bahamense 

as the Putative Toxin Source. Environmental Health Perspectives. 114(10):1502-1507. 123 Cited in Abbott,G. M., J. H. Landsberg, A. R. Reich, K. A. Steidinger, S.Ketchen, and C. Blackmore. 

2009. Resource Guide for Public Health Response to Harmful Algal Blooms in Florida. Fish and Wildlife 

Research Institute Technical Report TR-14. viii + 132 p. <http://myfwc.com/research/redtide/taskforce/reports-presentations/resource-guide-for-public-health-response-to-harmful-algal-blooms-in-florida/> 

Accessed June 2011.

124 Cited in Abbott,G. M., J. H. Landsberg, A. R. Reich, K. A. Steidinger, S.Ketchen, and C. Blackmore. 

2009. Resource Guide for Public Health Response to Harmful Algal Blooms in Florida. Fish and Wildlife 

Research Institute Technical Report TR-14. viii + 132 p. <http://myfwc.com/research/redtide/taskforce/reports-presentations/resource-guide-for-public-health-response-to-harmful-algal-blooms-in-florida/> 

Accessed June 2011.

125 Abbott,G. M., J. H. Landsberg, A. R. Reich, K. A. Steidinger, S.Ketchen, and C. Blackmore. 2009. 

Resource Guide for Public Health Response to Harmful Algal Blooms in Florida. Fish and Wildlife 

Research Institute Technical Report TR-14. viii + 132 p. <http://myfwc.com/research/redtide/taskforce/reports-presentations/resource-guide-for-public-health-response-to-harmful-algal-blooms-in-florida/> 

Accessed June 2011.
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values.126 In 2006, U.S. sportfishers spent $42.0 billion on fishing, including $26.3 

billion for freshwater fishing and $8.9 billion for saltwater fishing. These costs include 

trip-related costs (food, lodging), fishing equipment costs, and other costs such as 

licenses, land-leasing, and ownership.127 Commercial harvests of fish and shellfish totaled 

$3.9 billion nationally in 2009.128

The economic value of Florida’s marine recreational fisheries is higher than any 

other state in the country. Recreational fishing contributed over $5 billion to Florida’s 

economy. In the 2008/2009 fiscal year, over 1 million individuals bought a marine 

recreational fishing license, generating over $29 million in revenue.129Similarly, Florida 

has one of the nation’s top producing commercial fisheries. In 2009, Florida’s harvest of

the top five commercial species of fish and shellfish was worth more than $55 million 

combined. In total, commercial fishing contributed more than $1 billion to the economy 

of Florida. Outdoor recreation in Florida (including wildlife-viewing, fishing, and water 

sports) generates $10.1 billion annually.130 In 2006, over 3 million Florida residents and 

 126 Dodds, Walter K., Wes W. Bouska, Jeffrey L. Eitzmann, Tyler J. Pilger, Kristen L. Pitts, Alyssa J. 

Riley, Joshua T. Schloesser, and Darren J. Thornbrugh. 2009. Eutrophication of U.S. Freshwaters: Analysis 

of Potential Economic Damage. Environmental Science and Technology, Vol. 43, No. 1, 2009. 127 USFWS. 2006. 2006 National Survey of Fishing, Hunting, and Wildlife-Associated Recreation Errata 

Sheet for National Report. U.S. Fish and Wildlife Service. <http://www.census.gov/prod/2008pubs/fhw06-

errata.pdf>. Accessed July 2011.

USFWS. 2006. 2006 National Survey of Fishing, Hunting, and Wildlife-Associated Recreation: Florida. 

U.S. Fish and Wildlife Service. <http://www.census.gov/prod/2008pubs/fhw06-fl.pdf>. Accessed July

2011.

128 NOAA. 2009. Fisheries of the United States—2009. National Oceanic and Atmospheric Administration, 

National Marine Fisheries Service. <http://www.st.nmfs.noaa.gov/st1/fus/fus09/02_commercial2009.pdf>. 

Accessed July 2011.

129 FFWCC. 2011. The Economic Impact of Saltwater Fishing in Florida. Florida Fish and Wildlife 

Conservation Commission. <http://myfwc.com/conservation/value/saltwater-fishing>. Accessed December 

2011.

130 FFWCC. No Date. Outdoor Recreation. Florida Fish and Wildlife Conservation Commission.

<http://myfwc.com/conservation/value/outdoor-recreation>. Accessed July 2011.
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746,000 visitors participated in wildlife-viewing activities, for total retail sales of an 

estimated $3.1 billion.131

At the county level, finfish and shellfish are important to Florida Bay and Monroe 

County’s commercial tourism and fishing industries. Measurable economic losses 

associated with the changing environmental conditions of the Bay have occurred, 

primarily from the substantial decline in pink shrimp harvests. From 1986 through the 

early 1990s, employment in commercial fishing declined by about 10 percent, while 

income of individuals in the industry declined by $16 million. These losses coincided 

with massive seagrass die-offs in the bay and blue-green algae blooms.

132

HAB toxins can make seafood unsafe for human consumption, leading to an 

overall reduction in the amount of fish purchased due to the real or perceived threats of 

contamination.

133 Additional costs for medical care to treat individuals exposed to toxins 

are also an economic burden associated with HABs. Economic impacts from nitrogen and 

phosphorus pollution in Florida include monetary losses due to depressed fisheries, 

tourism and property values, and elevated costs to address nutrient impacts (e.g., beach 

cleanup costs, HAB monitoring). 

Reduction in seagrass habitat due to nitrogen and phosphorus pollution negatively 

impacts ecosystem services. FDEP has estimated that each acre of seagrass is worth 

 131 USFWS. 2006. 2006 National Survey of Fishing, Hunting, and Wildlife-Associated Recreation: Florida.

U.S. Fish and Wildlife Service. <http://www.census.gov/prod/2008pubs/fhw06-fl.pdf>. Accessed July 

2011.

132 Gorte, Ross W. 1994. The Florida bay economy and changing environmental conditions. 94-435 ENR, 

CRS Report for Congress, Congressional Research Service, The Library of Congress. 133 WHOI. 2008. Hearing on “Harmful Algal Blooms: The Challenges on the Nation’s Coastlines”. Woods 

Hole Oceanographic Institution. <http://www.whoi.edu/page.do?pid=8916&tid=282&cid=46007>. 

Accessed December 2011.
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$20,255 per year, which would translate to a benefit of $44.6 billion statewide.

134

Florida’s nearshore waters contain nearly 2.2 million acres of seagrass beds, which 

provide an estimated $40 billion of ecological services annually including support for fish 

and shellfish that are economically vital to commercial and recreational businesses in 

Florida.135 Some estuary experts have attempted to quantify the overall value of 

individual estuaries in Florida. For example, the Indian River Lagoon National Estuary 

Program estimated the total value of the Indian River Lagoon at $46.7 billion. In the 

study, recreational and non-use values of the lagoon were estimated to increase by nearly 

$80 million per year if there were a significant increase in the amount and diversity of 

 134 USGS 2001. Seagrass Habitat In the Northern Gulf of Mexico: Degradation, Conservation,

and Restoration of a Valuable Resource. USGS Gulf of Mexico Habitat Program Team,

855-R-04-001.

Burkholder, J.M., D.A. Tomasko, and B.W. Touchette. 2007. Seagrasses and eutrophication. Journal of 

Experimental Marine Biology and Ecology 350: 46-72.

Waycott, M. C.M. Duarte, T.J.B. Carruthers, R.J. Orth, W.C. Dennison, S. Olyarnik, A. Calladine, J.W. 

Fourqurean, K.L. Heck, Jr., A. R. Hughes, G.A. Kendrick, W.J. Kenworthy, F.T. Short, and S.L. Williams. 

2009. Accelerating loss of seagrasses across the globe threatens coastal ecosystems. Proceedings of the 

National Academy of Sciences of the United States of America 106(30): 12377-12381.

Short, F.T., B. Polidoro, S.R. Livingstone, K.E. Carpenter, S. Bandeira, J.S. Bujang, H.P. Calumpong, 

T.J.B. Carruthers, R.G. Coles, W.C. Dennison, P.L.A. Erftemeijer, M.D. Fortes, A.S. Freeman, T.G.

Jagtap, A.H.M. Kamal, G.A. Kendrick, W.J. Kenworthy, Y.A. La Nafie, I.M. Nasution, R.J. Orth, A. 

Prathep, J.C. Sanciangco, B. van Tussenbroek, S.G. Vergara, M. Waycott, and J.C. Zieman. 2011. In press. 

Extinction risk assessment of the world’s seagrass species. Biological Conservation.

Watson R.A., R.G. Coles, and W.J. Lee Long. 1993. Simulation estimates of annual yield and landed value 

for commercial penaeid prawns from a tropical seagrass habitat. Australian Journal of Marine and 

Freshwater Research 44:211–219.

Carlson, P. and L. Yarbro. 2008. Seagrass Mapping and Monitoring: Big Bend and Beyond. Presented at 

Florida Water Resources Monitoring Council Meeting, St. Petersburg, FL, September 24-25, 2008.

Costanza, R., R. d’Arge, R. de Groot, S. Farber, M. Grasso, B. Hannon, K. Limburg, S. Naeem, R.V. Neill, 

J. Paruelo, R.G. Raskin, P. Sutton, and M. van den Belt. 1997. The value of the world’s ecosystem services 

and natural capital. Nature 387:253–260. 135 FDEP. 2011. Celebrate Seagrass Awareness Month. Florida Department of Environmental Protection. 

<http://www.dep.state.fl.us/coastal/news/articles/2011/1103_Seagrass.htm>. Accessed June 2011.

FDEP. 2011. Seagrass Awareness Month. Florida Department of Environmental Protection. 

<http://www.dep.state.fl.us/coastal/habitats/seagrass/awareness/Proclamation_2011.pdf>. Accessed June 

2011.
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wildlife in the lagoon, as well as increased water quality throughout the system from 

restoration and water quality improvement projects.136

According to a study on the impacts of HABs on beachfront tourism-dependent 

businesses in the Ft. Walton Beach and Destin areas of Florida, HABs reduced restaurant 

and lodging revenues by $2.8 million and $3.7 million per month, respectively, 

representing a 29 percent to 35 percent decline in average monthly revenues.137

To estimate the various economic impacts of nutrients, one national study 

compared ambient concentrations of total nitrogen (TN) and total phosphorus (TP) in 

freshwater lakes with EPA’s criteria developed for the fourteen nutrient ecoregions

across the U.S.

138 The study provides conservative annual estimates of economic losses 

due to nitrogen and phosphorus pollution: decreased recreational water usage ($1 billion), 

waterfront property devaluation ($0.3 to $2.8 billion), recovery efforts for threatened and 

endangered species ($44 million), and additional treatment for drinking water ($813 

million). These potential losses total over $2.2 billion annually.139

A study by Mather Economics estimated the effects of water quality on real estate 

value in the South Florida Water Management District. The aggregate owner-occupied 

 136 USEPA. 2009. Determining an Estuary’s Economic Value. EPA-842F09001. U.S. Environmental 

Protection Agency, National Estuary Program. 

<http://water.epa.gov/type/oceb/nep/upload/2009_05_28_estuaries_inaction_Efficient_IndianRiver.pdf>. 

Accessed July 2011.

137 Larkin, S.L., and C.M. Adams. 2007. Harmful algal blooms and coastal business: economic 

consequences in Florida. Society & Natural Resources 20: 9, 849-859. 138 Under CWA section 304(a), EPA periodically publishes criteria recommendations for use by states in 

setting water quality criteria for particular parameters to protect recreational and aquatic life uses of waters. 

EPA produced nutrient criteria for lakes and reservoirs in 12 of the 14 ecoregions across the country. See 

USEPA. 2011. Ecoregional Nutrient Criteria Documents for Lakes & Reservoirs. United States 

Environmental Protection Agency. < 

http://water.epa.gov/scitech/swguidance/standards/criteria/nutrients/ecoregions/ecoregions_lakes_index.cf

m>. Accessed January 2012.

139 Dodds, Walter K., Wes W. Bouska, Jeffrey L. Eitzmann, Tyler J. Pilger, Kristen L. Pitts, Alyssa J. 

Riley, Joshua T. Schloesser, and Darren J. Thornbrugh. 2009. Eutrophication of U.S. Freshwaters: Analysis 

of Potential Economic Damage. Environmental Science and Technology, Vol. 43, No. 1, 2009.
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residential real estate value in the 16-county South Florida Water Management District is 

approximately $976 billion. Assuming that water quality (measured by dissolved oxygen

levels) can be returned to 1970 levels as a result of restoring the Everglades (a potential 

23.4 percent improvement in water quality), the study found that would translate into $16

billion in increased real estate values.

140

In addition to negatively impacting Florida businesses, nitrogen and phosphorus 

pollution increases costs for beach cleanup, HAB monitoring, and wastewater treatment. 

Approximately $63,000 was spent annually from 1995-1997 to dispose of red seaweed 

and fish killed by HAB events that littered 17.5 miles of beach in Sarasota County.

141

In addition, there are increased costs due to the need to treat polluted sources of 

drinking water. As an example of increased costs for drinking water treatment, 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 $3,000 

per day.142 Fremont, Ohio (a city of approximately 20,000) has experienced high levels of 

nitrate from its drinking water source, the Sandusky River, resulting in numerous 

drinking water use advisories. An estimated $15 million is needed to build a reservoir 

(and associated piping) that will allow for selective withdrawal from the river to avoid 

 140 McCormick, B., R.C. Clement, D. Fischer, M. Lindsay, R. Watson, et al. Measuring the Economic 

Benefits of America’s Everglades Restoration: An Economic Evaluation of Ecosystem Services Affiliated 

with the World’s Largest Ecosystem Restoration Project. Prepared for the Everglades Foundation by 

Mather Economics, Roswell, GA.

141 Hoagland, P., D.M. Anderson, Y. Kaoru, and A.W. White. 2002. The economic effects of harmful algal 

blooms in the United States: estimates, assessment issues, and information needs. Estuaries 25:819-837. 142 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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elevated levels of nitrate and provide storage.143 By regulating allowable levels of 

chlorophyll a in Oklahoma drinking water reservoirs, the Oklahoma Water Resources 

Board estimated that the long-term cost savings in averted drinking water treatment for 

86 systems would range between $106 million and $615 million if such regulations were 

implemented.144

B. Statutory and Regulatory Background

Section 303(c) of the CWA (33 U.S.C. 1313(c)) directs states to adopt water 

quality standards for their navigable waters. Section 303(c)(2)(A) and EPA's 

implementing regulations at 40 CFR 131 require, among other things, that state water 

quality standards include the designated use 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.” 40 CFR 131.10(b) provides that "[i]n designating uses of a water body

and the appropriate criteria for those uses, the state shall take into consideration the water 

quality standards of downstream waters and ensure that its water quality standards 

provide for the attainment and maintenance of the water quality standards of downstream 

waters.”

States are also required to review their water quality standards at least once every 

three years and, if appropriate, revise or adopt new standards. (See CWA section 

 143 Taft, Jim, Association of State Drinking Water Administrators (ASDWA). 2009. Personal 

Communication. 

144 Moershel, Philip, Oklahoma Water Resources Board (OWRB) and Mark Derischweiler, Oklahoma 

Department of Environmental Quality (ODEQ). 2009. Personal Communication.
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303(c)(1)). Any new or revised water quality standards 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.

C. Water Quality Criteria 

Under CWA section 304(a), EPA periodically publishes criteria 

recommendations 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 and 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,145 rivers and streams,146 and 

estuaries and coastal marine waters.147 EPA based the methodologies used to develop 

numeric nutrient criteria for Florida in this proposed regulation on these published 

guidance documents which identify three scientifically defensible approaches for 

deriving nutrient criteria: (1) the reference condition approach derives criteria from 

 145 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.

146 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.

147 USEPA. 2001. Nutrient Criteria Technical Manual: Estuarine and Coastal Marine Waters. EPA-822-B01-003. U.S. Environmental Protection Agency, Office of Water, Washington, DC.
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observations collected in reference water bodies or during reference time periods; (2) the 

mechanistic modeling approach represents contaminant loadings, hydrodynamics, and 

impacts in aquatic systems using equations that represent physical and ecological 

processes, calibrated using site-specific data; and (3) the stressor-response approach

estimates the relationship between nutrient concentrations and response measures related 

to a designated use of the water body. These three analytical approaches have been 

independently peer-reviewed and are appropriate for deriving scientifically defensible 

numeric nutrient criteria, taking into consideration the method-specific data needs and 

available data. In addition to these approaches, consideration of established (e.g., 

published and peer-reviewed) nutrient response thresholds is also an acceptable approach 

for deriving criteria.148

The criteria proposed 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 

Class I, II and III estuaries and coastal waters in Florida and flowing waters in the South 

Florida Region. In Florida, water quality criteria established for Class I, II and III surface 

waters must protect “fish consumption, recreation and the propagation and maintenance 

of a healthy, well-balanced population of fish and wildlife”149 Florida’s existing narrative 

nutrient provision serves to protect Class I, II and III waters from nitrogen and 

phosphorus pollution by requiring that “[i]n no case shall nutrient concentration of a body 

of water be altered so as to cause an imbalance in natural populations of aquatic flora or 

fauna.” After an extensive review of the latest scientific knowledge relating to the 

 148 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.

149 Pursuant to Subsection 62-302.400(4), F.A.C.
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impacts of nutrients to aquatic systems, EPA determined that three biological endpoints -

water clarity, dissolved oxygen, and phytoplankton biomass – effectively translate 

Florida’s narrative criterion. EPA further determined that this narrative criterion protects 

all designated uses, as a balanced natural population of aquatic flora and fauna is 

inherently necessary for fish consumption, recreation, and the propagation and 

maintenance of fish and wildlife. 

The criteria proposed 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) provides that (“[t]he discharge of nutrients shall continue to be limited as 

needed to prevent violations of other standards contained in this chapter. Human-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.”). 

Subsection 62-302.530(47)(a), F.A.C. remains in place as an applicable WQS for CWA 

purposes and could result in more stringent nitrogen and phosphorus limits than those 

proposed in this rule, where necessary to protect other applicable water quality standards

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 water quality standards in the form of numeric water quality criteria for 

nitrogen and phosphorus pollution are necessary to meet the requirements of the CWA in 

the State of Florida. EPA’s determination is available at the following Web site:

http://www.epa.gov/waterscience/standards/rules/fl-determination.htm. EPA determined 

that Florida’s narrative nutrient criterion alone was insufficient to ensure protection of 
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applicable designated uses. The determination recognized that Florida has a 

comprehensive regulatory and non-regulatory administrative water quality program to 

address nitrogen and phosphorus pollution through: a water quality strategy of 

assessments, non-attainment listing determinations, TMDL development, and NPDES 

permit regulations; individual watershed management plans through the State’s BMAPs; 

advanced wastewater treatment technology-based requirements under the 1990 GrizzleFigg Act; and rules to limit nitrogen and phosphorus pollution in geographically specific 

areas such as the Indian River Lagoon System and the Everglades Protection Area.

However, the determination noted that despite Florida’s existing regulatory and nonregulatory water quality framework and the State’s intensive efforts to diagnose nitrogen 

and phosphorus pollution, their reliance on a narrative criterion resulted in a timeconsuming and resource-intensive process. Substantial water quality degradation from 

nitrogen and phosphorus overenrichment remains a significant challenge in the State, and

EPA’s determination noted that conditions in Florida 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 the delays associated with a 

resource-intensive, site-specific implementation approach, does not ensure protection of 

applicable designated uses for the many State waters that either have been listed as 

impaired and require loading reductions or those that are high quality and require 

protection from future degradation. While Florida continues to work to implement their

watershed management program, the impairments caused by nutrient pollution are 
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steadily increasing as evidenced by the 2008 and 2010 Integrated Water Quality 

Assessment for Florida report results. Meanwhile, the tools to correct the impairments 

(TMDLs and BMAPs) are not being completed by the State at a pace to keep up with 

increases in nutrient pollution.

When implementing their existing narrative criterion to derive 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 results 

in a “reasonable potential” analysis that is more complex, data-intensive, and protracted.

Following a reasonable potential analysis, the State then evaluates levels of nitrogen and 

phosphorus that 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 statewide, water body-by-water body 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 water body, it can be 

very difficult to accurately determine appropriate targets 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 water body at 

the time of permitting issuance or re-issuance.

EPA determined that numeric criteria for nitrogen and phosphorus pollution 

would strengthen the foundation for identifying impaired waters, establishing TMDLs, 
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and deriving water quality-based effluent limits in NPDES permits, thus providing the 

necessary protection for the State’s designated uses in a timely manner, consistent with 

the requirements of the CWA. In addition, numeric criteria will support the State’s ability 

to effectively partner with point and non-point sources to control nitrogen and 

phosphorus pollution, thus further providing the necessary protection for the designated 

uses of the State’s water bodies.

The January 14, 2009 determination stated EPA’s intent to propose numeric 

criteria for lakes and flowing waters in Florida within 12 months, and for estuarine and 

coastal waters within 24 months of the determination. 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, effective 

on December 30, 2009, committing to the schedule stated in EPA’s January 14, 2009 

determination to establish numeric nutrient criteria for Florida’s lakes, flowing waters,

estuaries and coastal waters. The Consent Decree provided that if Florida submitted and 

EPA approved numeric nutrient criteria for the relevant water bodies before the dates 

outlined in the schedule, EPA would no longer be obligated to act on those water bodies.

On December 6, 2010, EPA promulgated numeric nutrient criteria for Florida’s 

lakes and flowing waters outside of the South Florida Region (40 CFR 131.43). The 2010 

“inland waters rule” was scheduled to take effect on March 6, 2012, with the exception of 

one provision that allows entities to submit Site-Specific Alternative Criteria (SSAC) that 

took effect on February 4, 2011. 

Since the promulgation of the December 6, 2010 final rule, EPA has continued to 

work in close coordination with the State of Florida as the State develops its own 
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rulemaking for numeric nutrient criteria. On November 10, 2011, FDEP proposed 

numeric nutrient criteria and related provisions for inland as well as a number of 

estuarine waters for the State (Clearwater Harbor/St. Joseph Sound; Tampa Bay; Sarasota 

Bay; Charlotte Harbor/Estero Bay; Tidal Cocohatchee River/Ten Thousand Islands; 

Florida Bay; Florida Keys; and Biscayne Bay), which were published in the Florida

Administrative Weekly (Volume 37, number 45, pages 3753–3775). On December 8, 

2011, the State’s Environmental Review Commission (ERC) approved these proposed 

rules with additional amendments and on December 9, 2011, FDEP submitted the ERCapproved rules and amendments to the Florida Legislature for ratification during the 2012 

legislative session. In order to avoid any confusion and inefficiency that may occur 

should Federal criteria become effective while State criteria are being finalized by the 

State and reviewed by EPA, EPA extended the March 6, 2012 effective date of the

Federal criteria for lakes and flowing waters outside of the South Florida Region to June 

4, 2012 through a subsequent rulemaking on XX.

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 the South Florida Region, and the downstream protection values for 

flowing waters into estuaries and coastal waters, to allow time for a public peer-review 

by EPA’s Science Advisory Board (SAB) of the scientific methodologies for numeric 

nutrient criteria development in each of these types of waters.

On September 30, 2011, EPA and Plaintiffs made further revisions to the 

deadlines in the Consent Decree. Under the revised Consent Decree, EPA is required to 

propose criteria for Florida’s estuaries, coastal waters and inland flowing waters in the 
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South Florida Region by March 15, 2012 and to finalize the criteria by November 15, 

2012. This proposed rule satisfies EPA’s requirement to propose criteria for these three 

categories of Florida waters by March 15, 2012.

In accordance with the January 14, 2009 determination, the December 30, 2009 

Consent Decree, and the June 7, 2010 and September 30, 2011 revisions to that Consent 

Decree, in this notice EPA is proposing numeric criteria for estuaries and coastal waters

in the State of Florida, and inland flowing waters in the South Florida Region.

150

III. Proposed Numeric Criteria for Florida’s Estuaries, Coastal Waters, and South 

Florida Inland Flowing Waters 

In this notice of proposed rulemaking, EPA is proposing numeric nutrient criteria 

to implement Florida’s narrative nutrient provision at Subsection 62-302.530(47)(b), 

F.A.C. This proposed rule also includes downstream protection values (DPVs) to ensure 

the attainment and maintenance of WQS in downstream estuarine and south Florida 

marine waters. The proposed criteria and related provisions in this rule reflect a detailed 

consideration of the best available scientific research, data, and analyses related to the 

specific circumstances for deriving numeric criteria in the State of Florida. EPA’s actions 

are consistent with and support existing Florida WQS regulations. 

In deriving scientifically sound numeric criteria for this proposed rulemaking, 

EPA relied on the local technical expertise of various scientific experts in Florida. EPA 

 150 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. EPA’s proposed criteria do 

not apply to flowing waters within the Everglades Protection Area (EvPA) or the Everglades Agricultural 

Area (EAA).
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met and consulted with FDEP’s scientific and technical experts during the development 

of these criteria as part of an ongoing collaborative process to analyze, evaluate, and 

interpret a substantial amount of Florida-specific data. EPA carefully evaluated the 

technical approaches and scientific analyses that FDEP presented as part of their draft 

approaches to develop numeric criteria for estuaries within the State. Finally, EPA also

carefully considered substantial stakeholder input from twelve public hearings conducted 

by FDEP during 2010, in addition to working with scientists from several Florida 

National Estuary Programs (NEPs), Water Management Districts, universities, and other

government agencies in Florida.

To further ensure the best use of available data and scientific analyses for deriving 

criteria, the Agency submitted its potential methods and approaches for evaluation by 

EPA’s Science Advisory Board (SAB) in November 2010 for an independent, scientific 

peer review process. The SAB reviewed the document entitled: Methods and Approaches 

for Numeric Nutrient Criteria for Nitrogen/Phosphorus Pollution in Florida’s Estuaries, 

Coastal Waters, and Southern Inland Flowing Waters, and submitted their final 

recommendations to EPA in July 2011.151 EPA used the SAB’s recommendations to 

refine the methods and approaches for deriving the criteria proposed in this rulemaking. 

Subsection III.A provides an overview of the technical elements used to support 

derivation of the numeric nutrient criteria proposed in today’s rulemaking.152 The 

 151 USEPA-SAB. 2011. Review of Methods and Approaches for Deriving Numeric Criteria for Nitrogen 

and Phosphorus Pollution in Florida’s Estuaries, Coastal Waters, and Southern Inland Flowing Waters. 

U.S. Environmental Protection Agency, Science Advisory Board, Washington, DC.

USEPA. 2010. Methods and Approaches for Deriving Numeric Criteria for Nitrogen and phosphorus 

Pollution in Florida’s Estuaries, Coastal Waters, and Southern Inland Flowing Waters. U.S. 

Environmental Protection Agency, Office of Water, Washington, DC.

152 Additional details are provided in a separate document, the Technical Support Document for U.S. EPA’s 

Proposed Rule for Numeric Nutrient Criteria for Florida’s Estuaries, Coastal Waters, and Southern Inland 
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remainder of Section III specifically describes EPA’s proposed numeric criteria for 

estuaries (subsection III.B), coastal waters (subsection III.C), south Florida marine waters 

(subsection III.D), and south Florida inland flowing waters (subsection III.E). These 

subsections include EPA’s proposal for segmenting water bodies and applicable criteria. 

Also included are proposed DPVs for estuaries (subsection III.B) and south Florida 

marine waters (subsection III.D). 

A. General Information and Approaches

For each group of waters addressed in Section III, EPA is proposing to use 

system-specific approaches for the derivation of numeric nutrient criteria to ensure that 

the diversity of unique ecosystems found in each type of water body is taken into 

consideration. This system-specific approach allows the Agency to consider the physical, 

chemical, and biological characteristics of a particular water body. This subsection 

describes the technical approaches EPA employed to derive the proposed criteria and 

DPVs, including (1) data and segmentation, (2) biological endpoints, and (3) analytical 

methodologies. For each group of water body types, EPA screened out data from 

impaired coastal, estuarine, or marine segments, based on the State’s CWA Section 

303(d) listing information, from scientific literature, EPA reports, local considerations of 

historical water quality, and State water quality data, and from mechanistic model results 

to determine whether segments were healthy.

1. Data Sources and Segmentation

a) Estuaries

 Flowing Waters (TSD); located at www.regulations.gov, Docket ID No. EPA-HQ-OW-2010-0222.
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Florida’s estuarine areas encompass approximately 1,950 square miles. EPA used 

the IWR Run 40 database to identify all available data from a range of sampling sites. To 

compute relationships between nutrient concentrations and chlorophyll a, EPA relied on 

measurements of Total Kjeldahl Nitrogen (TKN), TN, Nitrate-Nitrite (NO3-NO2), TP, 

and chlorophyll a from 1998-2009 . The resulting dataset included 180,814 samples, 

collected at 13,648 sites. The Agency also analyzed additional data submitted by local 

experts and organizations. 

Estuarine water quality and biological communities are affected by multiple 

factors related to the shape and size of the estuary, its connections to the ocean, geology, 

climate, and watershed characteristics (e.g., watershed area and land use) that affect the 

magnitude, location, and quality of freshwater inflows. For these reasons, EPA proposes 

to define individual estuarine systems based on salinity and the natural geographic 

features of estuarine basins and their associated watersheds. This approach has been 

utilized previously in development of the NOAA Coastal Assessment Framework.153

This approach is also consistent with a watershed approach to water quality management, 

which EPA encourages as a way to integrate and coordinate efforts within a watershed in 

order to most effectively and efficiently assess conditions and implement controls.154

EPA is proposing to sub-divide each estuarine system into segments based on 

physical factors and long-term average salinity gradients. Estuaries are complex and 

dynamic systems reflecting the mixing of fresh and marine water, and include different 

ecological zones across the salinity regime. These estuary segments are expected to have 

 153 NOAA. 2007. Coastal Assessment Framework (CAF). NOAA/NOS Special Projects Office - Coastal 

Geospatial Data Project. Silver Spring, MD. http://coastalgeospatial.noaa.gov/ 154 USEPA. 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.
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unique physical, chemical, and biological characteristics that may respond differently to 

nutrient inputs.155 EPA is proposing numeric criteria for 121 individual segments in 23 

estuaries. A detailed description and more detailed maps of EPA’s proposed withinestuary segments are provided in the TSD (Volume 1: Estuaries, Sub-chapter 1.3 and for 

each estuarine system in Chapter 2).

b) Coastal Waters

The available field monitoring data to support numeric criteria derivation for 

Florida’s coastal waters are less extensive than those available for estuaries. However, 

there are substantial data available from satellite remote sensing that can be used in a 

scientifically defensible and reliable way in conjunction with available field monitoring 

data to derive coastal numeric criteria for chlorophyll a. Satellite remote sensing 

technologies have been widely used156 to measure chlorophyll a in approximately 3,865 

square miles of coastal waters in Florida. These technologies allow consistent and 

reliable monitoring of expansive areas of Florida's coastline. EPA is not proposing to 

derive TN and TP criteria for coastal waters due to lack of sufficient coastal TN and TP 

data; however, EPA believes that the chlorophyll a criteria alone will provide the 

necessary protection of these waters. By applying chlorophyll a criteria to coastal waters, 

EPA is protecting a sensitive biological endpoint to serve as an early warning signal to 

the State that land-based sources may be causing imbalance to natural populations of 

aquatic flora and fauna in coastal waters.

 155 Telesh, I.V. and V.V. Khlebovich. 2010. Principal processes within the estuarine salinity gradient: A 

review. Marine Pollution Bulletin 61(4-6):149-155. 156 Gregg and Casey. 2004. Global and regional evaluation of the SeaWiFS chlorophyll data set. Remote 

Sensing of Environment. 93(4):463-479.
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The data EPA used to derive numeric chlorophyll a criteria for Florida’s coastal 

waters encompass a twelve year period of record (1998-2009). The length of this data 

record captures the long-term variability that has been observed in water quality within 

Florida’s coastal waters. To derive numeric criteria protective of coastal waters, EPA 

processed over 1,000 8-day composites of remotely sensed images from ocean color 

satellites. EPA also obtained field monitoring data for TN, TP, and chlorophyll a from 

FDEP IWR Run 40, the Northeastern Gulf of Mexico Chemical Oceanography and 

Hydrography Study (NEGOM), the Ecology and Oceanography of Harmful Algal 

Blooms Research Program (ECOHAB), the Florida Fish and Wildlife Conservation 

Commission Fish and Wildlife Research Institute (FWRI), Mote Marine Laboratory, and 

the Sea-viewing Wide Field-of-view Sensor (SeaWiFS)157 Bio-optical Archive and 

Storage System. Field monitoring data included over 5,500 chlorophyll a measurements, 

which were reduced to 1,947 after screening for data quality, as described below.

EPA screening factors were established to ensure data quality, as follows. Field 

monitoring data were required to have, at a minimum, metadata for date, time, latitude, 

longitude, and chlorophyll a or light attenuation information for all samples. Field 

monitoring data with latitude and longitude information rounded to the nearest degree or 

one-half degree were excluded because of lack of precision in terms of sampling location. 

Where multiple samples of chlorophyll a at different depths existed, the sample closest to 

the surface was utilized in order to provide a better comparison to the remotely sensed 

data. The monitoring sampling times were compared to the satellite overpass times. 

 157 NOTE: Sea WiFS has subsequently been replaced by MODIS and MERIS satellite generated data. EPA 

has developed an approach that can utilize these newer satellite data sources for ongoing assessment 

purposes.
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Samples falling within a plus or minus three hour time window were utilized to minimize 

variability between the sample time and satellite overpass time. Impaired coastal 

segments, based on the State’s CWA Section 303(d) listing, as well as segments adjacent 

to 303(d) impaired estuarine waters, were also screened out and removed from the 

analysis. Screening impaired WBIDs did not result in the complete removal of all data 

over the period of record, only data during the period of impairment. From these satellite 

measurements, EPA calculated average satellite-derived chlorophyll a (chlRS-a) values 

over an eight-day period based on data from 1998-2009 in each coastal segment. The 

eight-day binning period is a standard approach based on the satellite orbit repeat period 

of 16 days for the SeaWiFS satellite.158

For the purposes of deriving criteria, EPA is proposing to exclude chlRSmeasurements taken during known bloom events of Karenia brevis, from the statistical 

distribution of coastal data. Karenia brevis is a dinoflagellate responsible for red tide.

Satellites can detect K. brevis blooms when cell counts are above 50,000 cells/L. Coastal 

segments with an FWRI count greater than 50,000 cells/L during an 8-day composite 

were flagged and not included into the chlRS-a distributions.159 In addition, the same 

WBID is flagged one week prior to and after a bloom detection to provide a temporal 

buffer as blooms are transported along the coast. While FWRI sampling procedure is 

 158 Campbell, J.W., J.M. Blaisdell, and M. Darzi. 1995. Volume 32, Level-3 SeaWiFS Data Products: 

Spatial and Temporal Binning Algorithms. In: SeaWiFS Technical Report Series, NASA Technical 

Memorandum 104566, Vol 32. Hooker, S.B., E.R. Firestone, and J.G. Acker, eds. National Aeronautics and 

Space Administration. Greenbelt, Maryland. 

159 Heil, C.A. and K.A. Steidinger. 2009. Monitoring, management, and mitigation of Karenia blooms in 

the Eastern Gulf of Mexico. Harmful Algae. 8:611-617.
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robust, covering the vast spatial area of coastal Florida remains a challenge160 and it is 

possible that K. brevis blooms may go undetected and therefore unflagged.

This proposed approach is consistent with recommendations of the Agency’s 

Science Advisory Board, which recommended EPA screen out these data points, as they 

are likely not representative of reference conditions.

161 Analyses of cumulative 

distributions of chlRS-a show they are minimally affected by inclusion or removal of 

observations affected by K. brevis. EPA divided Florida’s coastal waters into three main 

areas: the Florida Panhandle, West Florida Shelf, and Atlantic Coast. These three coastal 

areas were initially subdivided into a total of 76 segments based on FDEP’s Water Body 

Identification System (WBIDs). EPA relied on physical factors, the optical properties of 

the coastal areas, water quality characteristics, and the jurisdictional limits of the Clean 

Water Act (i.e., three nautical mile seaward limit) to further refine these three areas, 

resulting in 74 segments. A detailed description of EPA’s data screening process and a 

map of the coastal waters are provided in the TSD (Volume 2: Coastal Waters, Subchapter 1.4).

c) South Florida Marine Waters

For purposes of this proposal, “south Florida marine waters” refers to combined 

estuarine and coastal waters south of the Caloosahatchee River watershed on Florida’s 

west coast and the St. Lucie River watershed on Florida’s east coast, including marine 

waters around the Florida Keys and Dry Tortugas. This region encompasses 

approximately 3,155 square miles. EPA utilized water quality monitoring data from 335 

 160 Id. 161 USEPA-SAB. 2011. Review of Methods and Approaches for Deriving Numeric Criteria for Nitrogen 

and Phosphorus Pollution in Florida’s Estuaries, Coastal Waters, and Southern Inland Flowing Waters. 

U.S. Environmental Protection Agency, Science Advisory Board, Washington, DC.
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sampling sites, provided by the Southeast Environmental Research Center (SERC) Water 

Quality Monitoring Network. A total of 31,931 samples resulted in 31,300 chlorophyll a, 

31,883 TN, and 31,838 TP concentrations that EPA evaluated to spatially segment and 

compute criteria for south Florida marine waters. EPA screened the water quality data 

based on its review of the scientific literature, state 303(d) water quality assessments, and 

local considerations of historical water quality. EPA took these measures to ensure that 

the data used to derive numeric criteria are representative of the water quality and reflect 

conditions that are biologically healthy and free from known human disturbances (e.g., 

bridge and roadway construction). Further details regarding data screening can be found 

in the TSD (Volume 3: South Florida Marine Waters, and Inland Flowing Waters, 

Chapter 1).

EPA is proposing to segment the south Florida marine waters using data from 

extensive water quality monitoring in this region. Physical classification based on water 

body shape and salinity that was applied to other marine waters in Florida was not 

applicable to these south Florida marine waters because the South Florida region lacks 

major rivers and there is an open connection between these waters and the oceans. 

Instead, EPA, with the assistance of scientists from the National Park Service (NPS) and 

Florida International University (FIU), used cluster analysis to segment these waters 

based on similarities in water quality. Cluster analysis is a mathematical method that 

groups samples that are most similar with one another. The cluster analysis resulted in 40 

different segments delineated for criteria development, and is similar to the approach 

used by FIU and NPS to segment marine waters of south Florida and proposed by FDEP 
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in 2011. This approach has been well established in south Florida’s scientific literature 

over the last 15 years. 

Additional details and a map of the segments are provided in the TSD (Volume 3: 

South Florida Marine Waters, and Inland Flowing Waters, Chapter 1).

d) Request for Comment on Data and Segmentation

EPA believes the data and segmentation approaches utilized provides a strong 

foundation for the derivation of numeric nutrient criteria that will protect the designated 

uses in Florida's estuaries, coastal waters. However, the Agency is soliciting additional 

relevant data and information to assist in the derivation of numeric criteria. Relevant data 

and information includes, but is not limited to: monitoring data for DO, chlorophyll a, 

total nitrogen, total phosphorus, total Kjeldhal nitrogen (TKN), dissolved organic 

nitrogen, dissolved organic phosphorus, dissolved inorganic nitrogen, dissolved inorganic 

phosphorus, and nitrate+nitrite. EPA also invites comment on the timeframe of the data 

used to derive criteria. 

EPA is requesting comment on the procedures used to screen data to ensure 

representativeness of conditions that are supporting balance populations of aquatic flora 

and fauna. In addition, EPA requests comment on excluding chlRS-a measurements taken 

during known bloom events of Karenia brevis, from the statistical distribution of coastal 

data, given the significance of red tide in Florida and the ongoing public engagement on 

this issue.

EPA also solicits comment on and requests any additional available information 

regarding the ability of the proposed segmentation approaches to account for the unique 

water quality conditions that can be found in estuarine and coastal waters throughout the
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State. Finally, Numeric nutrient criteria are derived using a system-specific approach. 

EPA requests comment on the spatial scale of criteria derivation, and if a broader spatial 

approach would be more appropriate.

2. Biological Endpoints

When deriving numeric criteria it is important to identify nutrient sensitive 

biological endpoints relevant to particular estuarine and coastal systems. These endpoints 

serve as sensitive measures to translate the State’s current narrative nutrient provision 

into protective concentrations of chlorophyll a, TN, and TP that, in turn, will ensure the 

overall support of balanced natural populations of aquatic flora and fauna. EPA 

conducted an extensive evaluation of available scientific literature to select appropriate 

biological endpoints, reviewing over 800 documents. From this review of the latest 

scientific knowledge, EPA has determined that chlorophyll a, water clarity, and DO as 

measurements of excessive algal growth are three sensitive biological endpoints to use in 

the translation of the State’s narrative criteria. 

Information on these biological endpoints was used as the basis for the 

development of proposed criteria for chlorophyll a, TN, and TP necessary to: (1) 

maintain water clarity to achieve seagrass depth of colonization targets, (2) reduce the 

risk of phytoplankton blooms, and (3) maintain dissolved oxygen concentrations 

sufficient for healthy and balanced aquatic life. The three biological endpoints provide a 

scientifically defensible basis upon which to derive criteria to ensure consistency of 

conditions for balanced natural populations of aquatic flora and fauna over the full range 

of estuarine and coastal conditions across Florida. 
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a) Healthy Seagrass Colonization at Historical Depths 

Seagrasses were selected as a biological endpoint because they are critical aquatic 

flora in most estuarine systems throughout Florida. Seagrasses provide essential habitat 

for many aquatic species and serve other key ecological functions. Seagrasses cover 

approximately 2.7 million acres throughout the State and are a central ecological feature 

of Florida’s dynamic, highly productive marine ecosystems.162 An endpoint based on 

seagrasses was also used by the NEPs and FDEP to derive their recommended estuarine 

criteria because of seagrass sensitivity to nutrient over-enrichment.

Seagrasses are an important indicator of biological integrity in systems where 

they have been historically present. Because of the unique conditions that are created 

within seagrass communities, populations of other floral and faunal species benefit from 

the presence and abundance of seagrasses.163 For example, seagrasses act as nurseries for 

many species by providing refuge from predators. Seagrasses also improve water quality 

by trapping suspended sediments, preventing sediment resuspension, and retaining 

nutrients. Healthy populations of seagrasses serve as an important and widely recognized 

indicator of biological integrity of estuarine systems and, in turn, of balanced natural 

populations of aquatic flora and fauna.164

 162 Florida Marine Research Institute. 2003. Conserving Florida's Seagrass Resources: Developing a 

Coordinated Statewide Management Program. Florida Marine Research Institute. St. Petersburg, FL

163 Orth, R.J., T.J.B. Carruthers, W.C. Dennison, C.M. Duarte, J.W. Fourqurean, K.L. Heck Jr., A.R. 

Hughes, G.A. Kendrick, W.J. Kenworthy, S. Olyarnik, F.T. Short, M. Waycott, and S.L. Williams. 2006. A 

global crisis for seagrass ecosystems. Bioscience 56:987-996. 164 Ferdie, M. and J.W. Fourqurean. 2004. Responses of seagrass communities to fertilization along a 

gradient of relative availability of nitrogen and phosphorus in a carbonate environment. Limnology and 

Oceanography 49(6):2082-2094.

Orth, R.J., T.J.B. Carruthers, W.C. Dennison, C.M. Duarte, J.W. Fourqurean, K.L. Heck, A.R. Hughes, 

G.A. Kendrick, W.J. Kenworthy, S. Olyarnik, F.T. Short, M. Waycott, and S.L. Williams. 2006. A global 

crisis for seagrass ecosystems. BioScience 56(12):987-996.

Doren, R.F., J.C. Trexler, A.D. Gottlieb, and M.C. Harwell. 2009. Ecological indicators for system-wide 
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Seagrass communities depend on a variety of physical, chemical, and biological 

conditions to thrive. Among these, adequate underwater light availability (as measured by 

water clarity) is critical for seagrass health. The relationship between water clarity and 

the depth to which seagrasses grow, known as the depth of colonization, has been welldocumented.165 EPA reviewed studies that empirically assessed the relationship between 

seagrasses and available light 166 and concluded that, for Florida, an average value of 20 

percent of incident light penetrating from the surface to the depth of colonization is 

necessary to protect seagrasses from impairment due to light attenuation in the water. A 

similar value has been used in previous nutrient management efforts in Florida. 167 Using

the 20 percent incident light value, EPA was able to relate water quality, namely water 

 assessment of the greater everglades ecosystem restoration program. Ecological Indicators 9:S2-S16.

Gibson, G.R., M.L. Bowman, J. Gerritsen, and B.D. Snyder. 2000. Estuarine and Coastal Marine Waters: 

Bioassessment and Biocriteria Technical Guidance. EPA 822-B-00-024. U.S. Environmental Protection 

Agency, Office of Water. 

http://water.epa.gov/scitech/swguidance/standards/criteria/aqlife/biocriteria/upload/2009_04_22_biocriteria

_States_estuaries_estuaries.pdf. Accessed November 2011.

165 Dennison, W.C. 1987. Effects of light on seagrass photosynthesis, growth, and depth distribution. 

Aquatic Botany. 27:15-26.

Dennison, W.C., R.J. Orth, K.A. Moore, J.C. Stevenson, V. Carter, S. Kollar, P.W. Bergstrom, and R.A. 

Batiuk. 1993. Assessing water quality with submersed aquatic vegetation. BioScience 43(2):86-94.

Duarte, C.M. 1991. Seagrass depth limits. Aquatic Botany 40(4):363-377.

Gallegos, C.L. 1994. Refining habitat requirements of submersed aquatic vegetation: Role of optical 

models. Estuaries 17(1):187-199.

Gallegos, C.L. and W.J. Kenworthy. 1996. Seagrass depth limits in the Indian River Lagoon (Florida, 

USA): Application of an optical water quality model. Estuarine Coastal and Shelf Science 42(3):267-288.

Gallegos, C.L. 2005. Optical water quality of a blackwater river estuary: the Lower St. Johns River, 

Florida, USA. Estuarine Coastal and Shelf Science 63(1-2):57-72.

Steward, J., R. Virnstein, L. Morris, and E. Lowe. 2005. Setting seagrass depth, coverage, and light targets 

for the Indian River Lagoon system, Florida. Estuaries and Coasts 28(6):923-935. 166 Dennison, W.C., R.J. Orth, K.A. Moore, J.C. Stevenson, V. Carter, S. Kollar, P.W. Bergstrom, and R.A. 

Batiuk. 1993. Assessing water quality with submersed aquatic vegetation. BioScience 43(2):86-94.

Duarte, C.M. 1991. Seagrass depth limits. Aquatic Botany 40(4):363-377.

Gallegos, C.L. 1994. Refining habitat requirements of submersed aquatic vegetation: Role of optical 

models. Estuaries 17(1):187-199.

Steward, J., R. Virnstein, L. Morris, and E. Lowe. 2005. Setting seagrass depth, coverage, and light targets 

for the Indian River Lagoon system, Florida. Estuaries and Coasts 28(6):923-935.

167 Janicki, A.J., and D.L. Wade. 1996. Estimating critical nitrogen loads for the Tampa Bay estuary: an 

empirically based approach to setting management targets. Technical Publication 06-96. Tampa Bay 

National Estuary Program. Prepared by Coastal Environmental, Inc.
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clarity and chlorophyll-a concentration, with seagrass health in Florida estuaries as a 

measure of balanced flora and fauna.

When seagrasses receive sufficient sunlight, seagrass biomass remains constant or 

increases over time. Conversely, when incoming light is blocked by substances in the 

water column, such as phytoplankton, suspended solids, or color, seagrass growth slows 

or stops. Studies on seagrasses have documented this relationship of nutrient-related algal 

growth to declines in available light and subsequent declines in seagrass communities.168

Since the area within an estuary available for seagrass growth is, in part, a function of the 

total area with enough sunlight at sufficient depths to sustain growth, as water clarity 

decreases and reduces the amount of sunlight that can reach the seagrasses, the available 

area for seagrass growth also decreases. 

EPA used extensive historical seagrass coverage data (the earliest available, 

generally 1940-1960) to compute historical depth of seagrass colonization. In the absence 

of historical data, more recent seagrass coverage data (e.g., 1992) were used. In all cases, 

current (2000-2010) seagrass coverage was also evaluated to determine existing depth of 

colonization, and to relate these values with existing water quality. To compute seagrass 

depth of colonization, EPA overlaid seagrass coverage data on bathymetric data compiled 

by NOAA using a Geographic Information System.169 EPA then developed target values 

for seagrass depth of colonization in Florida’s estuaries. Because studies examining 

biological utilization of seagrass habitats show that seagrass habitats support a rich array 

 168 Ferdie, M. and J.W. Fourqurean. 2004. Responses of seagrass communities to fertilization along a 

gradient of relative availability of nitrogen and phosphorus in a carbonate environment. Limnology and 

Oceanography 49(6):2082-2094. Orth, R.J., T.J.B. Carruthers, W.C. Dennison, C.M. Duarte, J.W. 

Fourqurean, K.L. Heck, A.R. Hughes, G.A. Kendrick, W.J. Kenworthy, S. Olyarnik, F.T. Short, M. 

Waycott, and S.L. Williams. 2006. A global crisis for seagrass ecosystems. BioScience 56(12):987-996.

169 Hagy and Jackson, in prep
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of seagrass-dependent biological uses,170 EPA concluded that water bodies in which 

seagrass coverage has decreased from historical coverage levels are not supporting 

balanced natural populations of aquatic flora or fauna. Where seagrass coverage has 

remained constant or increased over time, the goal of the numeric criteria is to maintain 

the greatest level of coverage. EPA then used data on past and present seagrass coverage 

to determine the maximum depths that seagrasses have been able to grow in each estuary, 

where applicable (i.e., this approach was not used in some estuaries in Florida that do not 

have historical evidence of seagrass colonization). These depths were then used as the 

targets for EPA’s proposed criteria. Using the requirement of 20% percent of incident 

light penetrating from the surface to the depth of colonization EPA then calculated a 

water clarity target to support seagrasses at the depth target and which was used to derive 

criteria to support a balanced natural populations of aquatic flora.

b) Phytoplankton Biomass 

Based upon the extensive review of current scientific literature noted above, EPA 

selected phytoplankton biomass as a second biological endpoint in estuaries because of 

its responsiveness to nutrient enrichment, integral role in aquatic food webs, long use as 

an integrative measure of aquatic ecosystem condition, and its correlation with changes in 

floral composition and subsequent faunal response.171 Chlorophyll a is the quantitative 

 170 Hughes, A. R., S. L. Williams, C. M. Duarte, K. L. Heck, Jr, and M. Waycott. 2009. Associations of 

concern: declining seagrasses and threatened dependent species. Frontiers in Ecology and the Environment 

7(5): 242-246 171 Boyer, J.N., C.R. Kelble, P.B. Ortner, and D.T. Rudnick. 2009. Phytoplankton bloom status: 

Chlorophyll a biomass as an indicator of water quality condition in the southern estuaries of Florida, USA. 

Ecological Indicators, 9s: s56-s67.

Hagy, J.D., J.C. Kurtz, and R.M. Greene. 2008. An approach for developing numeric nutrient criteria for a 

Gulf coast estuary. EPA 600R-08/004. Research Triangle Park, NC : U.S. Environmental Protection 

Agency, Office of Research and Development, National Health and Environmental Effects Research 

Laboratory.
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measure of phytoplankton biomass, and has a long history of use in aquatic ecology as a 

measure of phytoplankton biomass and production.172 Phytoplankton growth rate and 

biomass have been widely shown to increase with corresponding increases in nitrogen 

and phosphorus.173 In most of Florida’s coastal and estuarine waters, healthy biotic 

communities depend on balanced natural populations of phytoplankton because 

phytoplankton are integral components of aquatic food webs (e.g., provide the basic food 

source for many food webs, contribute to the success of filter-feeding organisms and 

organisms that rely on visual capture feeding methods) and aquatic nutrient cycling.174

Elevated chlorophyll a concentrations resulting from nutrient-enhanced 

phytoplankton growth and accumulation are a well-documented symptom of 

eutrophication and the adverse impacts from nutrient pollution across the nation and 

specifically in Florida (refer to subsection II.A for additional information).

EPA evaluated the available scientific literature to determine chlorophyll a

concentrations that were indicative of phytoplankton blooms or an imbalance in natural 

 

Bricker, S.B., C.G. Clement, D.E. Pirhalla, S.P. Orlando, and D.R.G. Farrow. 1999. National Estuarine 

Eutrophication Assessment. Effects of Nutrient Enrichment in the Nation’s Estuaries. NOAA—NOS 

Special Projects Office, Silver Spring, Maryland.

See Section B.3 in Appendix B of USEPA. 2010. Methods and Approaches for Deriving Numeric Criteria 

for Nitrogen and phosphorus Pollution in Florida’s Estuaries, Coastal Waters, and Southern Inland Flowing 

Waters. U.S. Environmental Protection Agency, Office of Water, Washington, DC. 172 Wetzel, R.G. 2001. Limnology, 3rd Edition. Academic Press, New York.

Kalff, J. 2002. Limnology: inland water ecosystems. Prentice-Hall, Upper Saddle River, New Jersey. 173 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.

Smith, V.H. 2006. Responses of estuarine and coastal marine phytoplankton to nitrogen and phosphorus 

enrichment. 51(1, part 2): 377–384

174 Hauxwell, J., C. Jacoby, T. Frazer, and J. Stevely. 2001. Nutrients and Florida’s Coastal Waters: The 

Links Between People, Increased Nutrients and Changes to Coastal Aquatic Systems. Florida Sea Grant 

Report No. SGEB-55. Florida Sea Grant College Program, University of Florida, Gainesville.

<http://edis.ifas.ufl.edu/pdffiles/SG/SG06100.pdf>. Accessed June 2011.

NOAA. No date. Overview of Harmful Algal Blooms. National Oceanic and Atmospheric Administration. 

<http://www.cop.noaa.gov/stressors/extremeevents/hab/default.aspx>. Accessed June 2011.
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populations of aquatic flora and fauna. Published reports on chlorophyll a concentrations 

in estuarine waters across the nation, including Florida estuaries, suggest that low algal 

bloom conditions are defined as maximum chlorophyll a concentrations less than 5 μg/L, 

medium bloom conditions defined as maximum chlorophyll a concentrations between 5-

20 μg/L, high bloom conditions defined as maximum chlorophyll a concentrations above 

20 μg/L, and hypereutrophic conditions are defined by bloom concentrations above 60 

μg/L.

175 Florida estuaries were analyzed as a part of a larger NOAA national survey of 

estuaries, and the authors reported the average bloom chlorophyll a concentrations were 

20 μg/L or less for seven of ten large Florida estuaries, especially low for Florida Bay (8 

μg/L) and Pensacola Bay (10 μg/L).176 EPA also evaluated other literature regarding 

phytoplankton blooms that indicated similar results.177

Based on the ranges of average chlorophyll a concentrations indicative of 

phytoplankton bloom conditions or characteristic of Florida estuaries, EPA selected a 

chlorophyll a concentration of 20 μg/L as the defining threshold for a nuisance 

phytoplankton bloom which was used in deriving numeric criteria. Where chlorophyll a

 175 Bricker et al. 2003 Bricker, S.B., J.G. Ferreira, and T. Simas. 2003. An integrated methodology for 

assessment of estuarine trophic status. Ecological Modelling 169(1):39-60. 176 Glibert, P.M., C.J. Madden, W. Boynton, D. Flemer, C. Heil, and J. Sharp. 2009. Estuarine Nutrient 

Criteria Development: State of the Science. United States Environmental Protection Agency, Office of 

Water, Washington, DC. 2009 Draft.

177 OECD (Organisation for Economic and Cooperative Development). 1982. Eutrophication of Waters: 

Monitoring, Assessment and Control. Organisation for Economic and Cooperative Development, Paris, 

France.

Painting, S.J., M.J. Devlin, S.J. Malcolm, E.R. Parker, D.K. Mills, C.Mills, P. Tett, A. Wither, J. Burt, R. 

Jones, and K. Winpenny. 2007. Assessing the impact of nutrient enrichment in estuaries: susceptibility to 

eutrophication. Marine Pollution Bulletin 55:74–90.

Painting, S.J., M.J. Devlin, S.I. Rogers, D.K. Mills, E.R. Parker, and H.L. Rees. 2005. Assessing the 

suitability of OSPAR EcoQOs for eutrophication vs. ICES criteria for England and Wales. Marine 

Pollution Bulletin 50:1569–1584

Tett, P., R. Gowen, D. Mills, T. Fernandes, L. Gilpin, M. Huxham, K. Kennington, P. Read, M. Service, M. 

Wilkinson, and S. Malcolm. 2007. Defining and detecting undesirable disturbance in the context of marine 

eutrophication. Marine Pollution Bulletin 55:282–297.
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concentrations exceed this threshold, it reflects an imbalance in estuarine waters. EPA 

also considered the available scientific studies described in this subsection to define an 

allowable frequency of occurrence of phytoplankton blooms, represented by chlorophyll 

a levels greater than 20 μg/L, to further define this endpoint when deriving numeric 

criteria. EPA selected a value of 10% as an allowable frequency of occurrence of 

phytoplankton blooms, which is also consistent with current nutrient management 

practices in Florida, such as those utilized in approved Florida TMDLs. 

c) Dissolved Oxygen

EPA selected dissolved oxygen (DO) as a third biological endpoint to derive 

numeric criteria for estuaries. As described in more detail above, DO concentrations are a 

well-known indicator of the health of estuarine and coastal biological communities. 

Aquatic animals including fish, benthic macroinvertebrates and zooplankton depend 

critically on levels of DO that meet the needs of all species and life stages (e.g., larval, 

juvenile, and adult).178

To derive numeric criteria using the DO endpoint, EPA conducted an analysis of 

the dissolved oxygen requirements of sensitive species using the Virginian Province 

dissolved oxygen evaluation procedure.179 The results of this analysis were used to 

determine that dissolved oxygen targets considered for modeling endpoints for numeric 

nutrient criteria development would ensure the protection of sensitive aquatic species in 

 178 Diaz, R.J. 2001; . Overview of hypoxia around the world. Journal of Environmental Quality 30(2):275-

281.

Diaz, R.J. and R. Rosenberg. 2008. Spreading dead zones and consequences for marine ecosystems. 

Science 321(5891):926-929.

179 Vincent, A.M., J. Flippin, E. Leppo, and J.D. Hagy III. Dissolved oxygen requirements of Floridaresident saltwater species applied to water quality criteria development. In review.

USEPA. 2000. Ambient Aquatic Life Water Quality Criteria for Dissolved Oxygen (Saltwater): Cape Cod 

to Cape Hatteras. Environmental Protection Agency, Office of Water, Washington D.C. PA-822-R-00-012.
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Florida estuaries. Based on levels of DO that meet the needs of sensitive aquatic animal 

species in Florida estuarine waters, EPA selected a minimum allowable water column 

average DO of 4.0 mg/L, a daily water column average DO of 5.0 mg/L, and a minimum 

bottom water average DO of 1.5 mg/L in estuarine waters for use in deriving numeric 

criteria. These values and interpretations are also consistent with existing Florida DO 

criteria [Subsection 62-302.530(30), F.A.C.] and FDEP’s assessment process [Subsection 

62-303.320(5), F.A.C.]. (More detail on both the existing Florida DO criteria and the 

EPA analysis is in the TSD, Volume 1: Estuaries, sections 1.2.3 (page 10) and 1.4.1 

(page 15)). 

d) Other Endpoints Considered by EPA

EPA considered, but is not proposing to use, the following nutrient-sensitive 

biological endpoints: (1) harmful algal blooms (HABs), (2) coral, (3) epiphytes, (4) 

macroinvertebrate and fish indices, (5) macroalgae, (6) Spartina marshes (salt-marshes), 

and (7) the Eastern oyster (Crassostrea virginica). These biological endpoints were not 

selected because there was an absence of sufficient data to quantify the link to nitrogen 

and phosphorus concentrations. Additional details on these alternative endpoints are 

provided in Appendix B in the Methods and Approaches for Deriving Numeric Criteria 

for Nitrogen/Phosphorus Pollution in Florida’s Estuaries, Coastal Waters, and Southern 

Inland Flowing Waters.

180

e) Request for Comment on Endpoints

 180 USEPA. 2010. Methods and Approaches for Deriving Numeric Criteria for Nitrogen and Phosphorus 

Pollution in Florida’s Estuaries, Coastal Waters, and Southern Inland Flowing Waters. U.S. 

Environmental Protection Agency, Office of Water, Washington, DC.
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EPA believes that the three biological endpoints of healthy seagrass colonization, 

phytoplankton biomass and dissolved oxygen are the appropriate nutrient sensitive 

endpoints to translate the State’s current narrative nutrient criteria to ensure that nutrient 

concentrations of a body of water do not cause an imbalance in natural populations of 

aquatic flora or fauna into numeric values that will, in turn protect the Class II and III 

designated waters in the State of Florida. EPA requests comment regarding the endpoints 

selected, as well as additional scientific information on other appropriate endpoints that 

can be used to translate the State’s narrative nutrient criteria to provide protection of fish 

consumption, recreation and the propagation and maintenance of healthy, well balanced 

population of fish and wildlife in Florida’s Class II and III estuarine and coastal waters. 

3. Analytical Methodologies

EPA used three analytical approaches to derive TN, TP, and chlorophyll a

numeric nutrient criteria: (1) reference condition approach, (2) stressor-response 

approach, and (3) mechanistic modeling. These approaches were applied to the available 

data in a particular water segment to allow the Agency to quantitatively link protective 

concentrations of nitrogen, phosphorus, and chlorophyll a to biological endpoints for that 

segment. These protective concentrations are defined as either the conditions that are 

currently healthy or least disturbed by human activities or alternatively defined by the 

predicted responses to nutrient load reductions necessary to meet the biological endpoint.

a) Reference Condition Approach

EPA applied the reference condition approach to derive numeric criteria in 

Florida estuaries and coastal waters that are currently healthy or least-disturbed by human 
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activities. To do so, EPA first ensured the waters have least disturbed conditions and are 

supporting designated uses. 

In coastal areas and south Florida marine waters, EPA reviewed 303(d) listings, 

and where impairments existed those data were removed to reflect healthy and 

unimpaired conditions. EPA then reviewed available monitoring information, peerreviewed literature, and technical reports from coastal areas and south Florida marine 

waters to ensure that these data were representative of waters that have least impacted 

conditions and are supporting designated uses. Furthermore, EPA removed data during 

periods of temporary known human disturbances (e.g., bridge and roadway 

construction).The resulting data were reflective of healthy, least impacted conditions in 

which endpoints were supported and thus were used in subsequent analyses. The 

screening steps are detailed in section III.A.1.b and III.A.1.c.

In estuaries, EPA used the mechanistic models to help determine whether water 

quality supported balanced populations of flora and fauna. Where quantitative biological 

endpoints existed, these endpoints (chlorophyll a, water clarity, and DO) were compared 

to the mechanistic modeling results as a way to determine the health of each estuary 

segment. Based on EPA's review of the latest scientific knowledge, EPA has determined 

that the endpoints described in section III.A.2 can be used to translate of the State’s 

narrative criteria, and thus signify whether a system is healthy least-disturbed. As a result, 

where the endpoints were achieved EPA determined that a reference approach could be 

used to derive criteria.

To derive criteria for coastal and estuarine systems using this reference approach, 

EPA identified nutrient concentrations that quantified the upper bound (90th percentile) of 
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the historical range (after data were screened for impairments) of observed concentrations

as the criteria. Thus, values lower than the derived criterion value occurred at least 90 

percent of the time in the period of record for these datasets. To derive this value, EPA 

first transformed individual data values to a natural logarithm, then calculated the annual 

geometric mean concentrations of TN, TP, and chlorophyll a for each year of the data 

record and for each segment. Even though coastal, marine, and estuarine waters were 

assigned to segments to ensure homogeneity of water quality across different locations 

within a segment, EPA recognizes that limited variability may still exist across locations 

within a given segment. Selection of this percentile reflects EPA's confidence that the 

majority of locations within a segment support balanced natural populations of aquatic 

flora and fauna.

b) Stressor-response Approach

The stressor-response approach uses monitoring data for each system to estimate 

a statistical relationship between TN, TP, and chlorophyll a and the biological endpoints. 

Criteria for TN, TP, and chlorophyll a are derived to achieve the biological endpoints 

selected by EPA to serve as measures of balanced natural populations of flora and fauna.

181 This approach was used in systems that EPA determined were not currently healthy 

and therefore a reference approach was not appropriate. EPA used the stressor-response 

approach to predict the biological response to nutrient load reductions, and from these 

predictions, derive numeric criteria, where data were available. EPA's assessment of 

system health was based on an evaluation of current water quality conditions to 

 181 USEPA. 2010. Using stressor-response relationships to derive numeric nutrient criteria. United States 

Environmental Protection Agency, Office of Water, Office of Science and Technology. EPA-820-S-10-

001.
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determine if they supported the biological endpoints of chlorophyll a, water clarity, and 

DO.

To determine chlorophyll a concentrations supportive of the water clarity depth 

target to achieve the healthy seagrass endpoint in a segment, EPA used logistic regression 

to estimate the relationship between chlorophyll a concentration and the probability that 

water clarity was greater than the water clarity target for the segment. Then, the 

chlorophyll a criterion was computed as the chlorophyll a concentration that was 

associated with a 50% probability of water clarity being greater than the clarity target. In 

other words, the chlorophyll a criterion should allow for water clarity targets to be met at 

least half of the days in a year, a level which has been shown sufficient for supporting 

healthy seagrass communities.182

As chlorophyll a is correlated with algal growth, increases in chlorophyll a 

concentrations are related to an increase in algae and decrease in dissolved oxygen. To 

determine candidate chlorophyll a criteria associated with DO endpoints, EPA first 

estimated the relationship between chlorophyll a concentration and the probability that 

DO endpoints were met. However, hourly measurements of DO, which are often 

necessary to accurately assess attainment of the DO endpoint, were only available in the 

St. Johns River estuary. In other estuaries, available DO data were not sufficient to permit 

a direct assessment of attainment of the DO endpoint. In these estuaries, EPA calculated 

the chlorophyll a concentration that was associated with a statistically significant 

decrease in DO concentrations. That is, candidate chlorophyll a criterion values were 

calculated to satisfy the DO endpoint in the one estuary where hourly data were available, 

 182 Dennison, W.C. 1987. Effects of light on seagrass photosynthesis, growth, and depth distribution. 

Aquatic Botany, 27:15-26.
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and in all other estuaries, the chlorophyll a criterion was calculated as the concentration 

below which increases in DO concentration were not associated with further reductions in 

chlorophyll a concentration. 

EPA also used stressor-response relationships to derive chlorophyll a criteria 

protective of the phytoplankton biomass endpoint. To this end, EPA used logistic 

regression to estimate the relationship between the annual geometric mean chlorophyll a

concentration and the probability of any single chlorophyll a measurement exceeding 20 

μg/L during the year. Then, a chlorophyll a criterion was derived from this relationship 

as the annual geometric mean concentration that ensured that single measurements 

exceeded 20 μg/L no more than 10% of the time. 

The final chlorophyll a criterion derived by stressor-response analysis was the 

lowest of the different criteria computed to satisfy the water clarity depth target, 

phytoplankton biomass endpoint, and DO endpoint. That is, the final chlorophyll a

criterion was selected to protect all endpoints in each estuary. To calculate TN and TP 

criteria associated with the chlorophyll a criterion, the relationship between annual 

geometric mean TN and TP and annual geometric mean chlorophyll a concentration was 

estimated for each estuary segment. TN and TP criteria were then computed from this 

relationship as the concentrations that are required to maintain average predicted 

chlorophyll a concentrations that are no higher than the chlorophyll a criterion. Because 

both TN and TP are included in the stressor-response analyses that predict chlorophyll a, 

many different combinations of TN and TP achieve the desired chlorophyll a criterion 

and are therefore protective of designated uses. To identify a single value of TN and a 

single value of TP, criteria are specified such that they represent the most frequent ratio 
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of TN to TP currently observed in the data. That is, criteria are specified as the ratio of 

TN and TP concentrations that are most common in current data. 

c) Mechanistic Modeling 

The third approach EPA used for deriving numeric criteria for estuaries employed 

integrated mechanistic simulation models of the coupled watershed-estuary system to 

interpolate water quality data that are sampled at particular locations and at particular 

times throughout each estuary and throughout the simulated time period. Specifically, 

EPA used watershed hydrology and water quality models coupled with estuarine 

hydrodynamic and water quality models to simulate the physical, chemical, and 

biological processes in a watershed-estuarine system. EPA used the watershed models to 

develop estimates of TN, TP, and freshwater inputs to the estuary. Next, EPA used the 

hydrodynamic and water quality models to simulate estuarine water quality responses, 

including estuarine TN, TP, and chlorophyll a concentrations, water clarity, and DO over 

the period of record. To select the models, EPA developed an inventory of watershed 

and estuary models that have been applied previously to estuaries in Florida, including 

models developed by FDEP.183 Based on the results of the review, EPA selected the 

Loading Simulation Program in C++ (LSPC)184 for simulating freshwater flows and 

nutrient loading from watersheds, the Environmental Fluid Dynamics Code (EFDC)185

 183 Wolfe 2007 Wolfe, S.H. 2007. An Inventory of Hydrodynamic, Water Quality, and Ecosystem Models of 

Florida Coastal and Ocean Waters. Florida Department of Environmental Protection. Tallahassee, Florida. 184 USEPA. 2011. Loading Simulation Program in C++ (LSPC). 

http://www.epa.gov/athens/wwqtsc/html/lspc.html. Accessed December 2011. 185 USEPA. 2011. Environmental Fluid Dynamics Code (EFDC). 

http://www.epa.gov/athens/wwqtsc/html/efdc.html. Accessed December 2011.
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for simulation of estuarine hydrodynamics, and the Water Quality Analysis Simulation 

Program (WASP)186 for simulation of estuarine water quality.187

LSPC can continuously simulate the hydrologic and water quality processes on 

pervious and impervious land surfaces, in streams, and in well-mixed impoundments and 

provided daily estimates of stream flow, TN and TP concentrations. In addition LSPC has 

been applied to many watersheds throughout the southeastern United States and Florida. 

Therefore, EPA applied the LSPC model to the watersheds in Florida north of the 

Caloosahatchee River watershed on the west coast and the St. Lucie River watershed on 

the east coast. 

Coupled hydrodynamic-water quality models using EFDC for hydrodynamics 

(i.e., physical processes) and WASP for water quality have been applied to many water 

quality management projects throughout the southeastern United States and Florida. 

Based on this extensive experience using these models for similar applications, EPA used 

the EFDC and WASP models for numeric criteria derivation for Florida estuaries. EFDC 

and WASP are both publicly available and have undergone external peer review by the 

EPA SAB.188

The process that EPA used for development of proposed numeric criteria using 

mechanistic models involved modeling the conditions and processes in both a watershed 

and corresponding estuary that occurred during the 2002-2009 timeframe using all 

 186 USEPA. 2011. Water Quality Analysis Simulation Program (WASP). 

http://www.epa.gov/athens/wwqtsc/html/wasp.html. Accessed December 2011. 187 USEPA. 2010. Methods and Approaches for Deriving Numeric Criteria for Nitrogen and phosphorus 

Pollution in Florida’s Estuaries, Coastal Waters, and Southern Inland Flowing Waters. U.S. 

Environmental Protection Agency, Office of Water, Washington, DC. 188 USEPA-SAB. 2011. Review of Methods and Approaches for Deriving Numeric Criteria for Nitrogen 

and Phosphorus Pollution in Florida’s Estuaries, Coastal Waters, and Southern Inland Flowing Waters. 

U.S. Environmental Protection Agency, Science Advisory Board, Washington, DC.
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available data. EPA chose a simulation period from 2002-2009 because it represented a 

wide range of seasonal and climatological conditions for the evaluation of the current 

water quality conditions and it contained the best available data. 

Output from the mechanistic models provided another means of interpreting 

available water quality data with respect to the biological endpoints (e.g., seagrass, 

phytoplankton biomass, or DO) (see Section III.A.2), and where required, mechanistic 

models provided a means of predicting nutrient load reductions to meet biological 

endpoints. 

For systems where monitoring data were insufficient to calculate criteria and the 

mechanistic model showed the system was least disturbed, EPA used the mechanistic 

model prediction of a concentration distribution to derive criteria. For systems that EPA 

determined were not least disturbed, EPA used mechanistic modeling to predict the 

reduced nutrient loads necessary to meet biological endpoints. Numeric criteria were 

derived from the concentrations of nutrients resulting from these reduced loadings.

Candidate numeric nutrient criteria for TN, TP, and chlorophyll a were then 

calculated as the 90th percentile of the annual geometric means for each estuary segment.

d) Use of Multiple Approaches within the criteria derivation framework

EPA considered multiple lines of evidence from these three main approaches to 

derive system-specific numeric nutrient criteria for coastal and estuarine waters of 

Florida. EPA first determined whether each water body appeared to support balanced 

natural populations of flora and fauna based on an extensive review of existing literature, 

consideration of local knowledge, consideration of 303(d) assessments of the water body 
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by FDEP, a quantitative assessment of field monitoring data with respect to all of the 

biological endpoints described in Section III.A.2., and a quantitative assessment of the 

predictions from mechanistic models based on nutrient loads that existed during the 

2002-2009 time period with respect to all of the biological endpoints. A reference 

condition approach using monitoring data, mechanistic model predictions, or satellite 

imagery was used to derive criteria for water bodies that EPA determined to be healthy. 

Criteria for water bodies that EPA determined were not healthy were derived by using the 

mechanistic models to calculate the load reductions necessary to achieve all biological 

endpoints, and by using stressor-response relationships to calculate concentrations of TN 

and TP necessary to achieve all biological endpoints. In all instances but one there were 

not sufficient data to apply the stressor-response approach in all segments in an estuary so 

mechanistic model predictions were used to derive criteria. In these instances EPA 

analyzed the stressor-response data to corroborate and support the proposed criteria, in 

segments where available.

e) Request for Comment on Analytical Methodologies

EPA believes that these analytical methodologies used in combination in this 

proposed rulemaking result in numeric criteria that are supportive of balanced natural 

populations of aquatic flora and fauna, and thus protect Class II and III estuarine and 

coastal waters in the State of Florida from nutrient pollution. These analytical 

methodologies utilized the latest scientific knowledge, nutrient sensitive endpoints, and 

the best available data. The Agency requests comment on the application of the proposed 

methodologies and whether these methodologies are appropriate to derive criteria 
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protective of designated uses in Florida's estuaries and coastal waters. Specifically, EPA 

is soliciting comment and any scientific information on the use of these approaches in 

areas where there may be other factors present that may also affect the three biological 

endpoints by attenuating light in similar ways as chlorophyll a (e.g., colored dissolved 

organic matter (CDOM) or suspended sediments). The Agency is also soliciting comment 

on its application of 90th percentile values of the screened data set to represent healthy 

and least disturbed conditions.

B. Proposed Numeric Criteria for Estuaries

1. Introduction

EPA is proposing to use a system-specific approach for the derivation of numeric 

nutrient criteria for estuaries to ensure that the unique attributes of each estuarine 

ecosystem are taken into account and addressed. This system-specific approach allows 

the Agency to consider the individual physical, chemical, and biological characteristics of 

each system. 189

2. Proposed Numeric Criteria (Estuaries) 

EPA is proposing numeric criteria for TN, TP, and chlorophyll a for 121 discrete 

segments within 23 estuarine systems in Florida (Table III.B-1). These include Class II 

and III waters under Florida law (Section 62-302.400, F.A.C.); no Class I estuarine 

waters were found by EPA. The 23 estuaries include five systems in the Florida 

 189 USEPA. 2001. The nutrient criteria technical manual: Estuarine and coastal waters. Office of Water. 

EPA-822-B-01-003.

Glibert, P.M. ,C.J Madden, W. Boynton, D. Flemer, C. Heil, and J. Sharp (eds.), 2010. Nutrients in 

Estuaries: A Summary Report of the National Estuarine Experts Workgroup, 2005–2007. Report to U.S. 

Environmental Protection Agency, Office of Water, Washington DC. 
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panhandle region, six systems in the Big Bend/Springs Coast region, four systems in 

southwest Florida, and eight systems along the Atlantic coast. Maps showing the 

locations of these estuaries and their segmentation are provided in the TSD (Volume 1: 

Estuaries, Chapter 1 and for each estuarine system in Chapter 2). 

Table III.B-1. EPA’s Proposed Numeric Criteria for Florida’s Estuaries (in 

geographic order from northwest to northeast)

Proposed Criteria

Perdido Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Upper Perdido Bay 0101 0.59 0.042 5.2

Big Lagoon 0102 0.26 0.019 4.9

Central Perdido 

Bay 0103 0.47 0.031 5.8

Lower Perdido Bay 0104 0.34 0.023 5.8

Pensacola Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Blackwater Bay 0201 0.55 0.022 3.9

Upper Escambia 

Bay 0202 0.43 0.025 3.7

East Bay 0203 0.50 0.021 4.2

Santa Rosa Sound 0204 0.31 0.018 4.1

Lower Escambia 

Bay 0205 0.42 0.024 3.9

Upper Pensacola 

Bay 0206 0.40 0.021 3.9
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Lower Pensacola 

Bay 0207 0.34 0.020 3.6

Santa Rosa Sound 0208 0.33 0.020 4.1

Santa Rosa Sound 0209 0.36 0.020 5.2

Choctawhatchee 

Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Eastern 

Choctawhatchee 

Bay

0301 0.61 0.035 4.1

Central 

Choctawhatchee 

Bay

0302 0.48 0.017 3.9

Western 

Choctawhatchee 

Bay

0303 0.41 0.015 3.5

St. Andrews Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

East Bay 0401 0.31 0.014 4.6

St. Andrews Sound 0402 0.14 0.009 2.3

Eastern St. Andrews 

Bay 0403 0.24 0.021 3.9

Western St. 

Andrews Bay 0404 0.19 0.016 3.1

Southern St. 

Andrews Bay 0405 0.15 0.013 2.6

North Bay 1 0406 0.22 0.012 3.7

North Bay 2 0407 0.22 0.014 3.7

North Bay 3 0408 0.21 0.016 3.4

West Bay 0409 0.23 0.022 3.8

St. Joseph Bay SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)
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St. Joseph Bay 0501 0.43 0.020 3.0

Apalachicola Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

St. George Sound 0601 0.53 0.019 3.6

Apalachicola Bay 0602 0.51 0.019 2.7

East Bay 0603 0.76 0.034 1.7

St. Vincent Sound 0605 0.52 0.016 12

Apalachicola / 

Offshore 0606 0.30 0.008 2.3

Alligator Harbor

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Alligator Harbor 0701 0.36 0.011 2.8

Alligator / Offshore 0702 0.33 0.009 3.1

Alligator / Offshore 0703 0.33 0.009 2.9

Ochlockonee Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Ochlockonee-St. 

Marks Offshore 0825 0.79 0.033 2.7

Ochlockonee

Offshore 0829 0.47 0.019 1.9

Ochlockonee Bay 0830 0.66 0.037 1.8

Ochlockonee Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

St. Marks River 

Offshore 0827 0.51 0.022 1.7

St. Marks River 0828 0.55 0.030 1.2

Big Bend/ 

Apalachee Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Econfina Offshore 0824 0.59 0.028 4.6

Econfina 0832 0.55 0.032 4.4

Big Bend/ 

Apalachee Bay SEGMENT SEGMENT ID TN*(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)
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Fenholloway 0822 1.15 0.44 1.9

Fenholloway 

Offshore 0823 0.48 0.034 10.3

Big Bend/ 

Apalachee Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

SteinhatcheeFenholloway 

Offshore 

0821 0.40 0.023 4.1

Big Bend/ 

Apalachee Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Steinhatchee River 0819 0.67 0.077 1.0

Steinhatchee 

Offshore 0820 0.34 0.018 3.5

Big Bend/ 

Apalachee Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Steinhatchee 

Offshore 0818 0.39 0.032 4.8

Suwannee River

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Suwannee Offshore 0817 1.1 0.090 3.7

Springs Coast

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Waccasassa River 

Offshore 0814 0.38 0.019 3.9

Waccasassa River 

Offshore 0815 0.32 0.019 4.1

Springs Coast

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Crystal River 0812 0.35 0.013 1.3

Crystal-Homosassa 

Offshore 0813 0.36 0.013 2.1

Springs Coast SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)
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Weeki Wachee 

River 0808 0.32 0.010 1.6

Weeki Wachee 

Offshore 0809 0.30 0.010 2.1

Springs Coast

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Pithlachascotee 

River 0806 0.50 0.022 2.4

Pithlachascotee 

Offshore 0807 0.32 0.011 2.5

Springs Coast

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Anclote River 0804 0.48 0.037 4.7

Anclote Offshore 0805 0.31 0.011 3.2

Clearwater 

Harbor/ St. 

Joseph Sound

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Clearwater Harbor 0801 0.47 0.029 5.7

St. Joseph Sound 0802 0.46 0.029 5.5

Clearwater HarborSt. Joseph Offshore 0803 0.29 0.008 2.6

Tampa Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Hillsborough Bay 0901 0.49 0.175 7.7

Old Tampa Bay 0902 0.44 0.172 12.9

Upper Tampa Bay 0903 0.44 0.152 7.9

Middle Tampa Bay 0904 0.37 0.116 6.3

Lower Tampa Bay 0905 0.31 0.074 4.9

Manatee River 0906 0.62 0.115 7.4

Boca Ciega 0907 0.30 0.086 5.3

Sarasota Bay SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Sarasota Bay 1001 0.28 0.119 7.7
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Palm Sola Bay 1002 0.34 0.141 7.2

Roberts Bay 1003 0.34 0.131 8.6

Little Sarasota Bay 1004 0.30 0.123 8.3

Blackburn Bay 1005 0.28 0.118 7.0

Dona Bay 1006 0.24 0.115 4.2

Charlotte Harbor

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Upper 

Caloosahatchee 1101 1.11 0.110 9.9

Lower 

Caloosahatchee 1102 0.61 0.083 3.5

Estero Bay 1103 0.65 0.072 2.3

Matlacha Pass 1104 0.57 0.076 1.6

San Carlos Bay 1105 0.57 0.060 2.4

Peace Estuary 1106 0.79 0.303 3.5

Myakka Estuary 1107 0.71 0.176 3.8

Upper Charlotte 

Harbor 1108 0.71 0.177 2.9

Lower Charlotte 

Harbor 1109 0.61 0.105 2.1

Pine Island Sound 1110 0.56 0.062 2.1

Lake Worth 

Lagoon

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

North Lake Worth 

Lagoon 1201 0.55 0.067 4.7

Central Lake 

Worth Lagoon 1202 0.57 0.089 7.6

South Lake Worth 

Lagoon 1203 0.48 0.034 6.8

Loxahatchee

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Lower Loxahatchee 1301 0.64 0.027 2.9

Middle 

Loxahatchee 1302 0.90 0.041 3.8

Upper Loxahatchee 1303 1.2 0.068 2.8

St. Lucie SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)
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Lower St. Lucie 1401 0.58 0.045 5.3

Middle St. Lucie 1402 0.90 0.12 8.4

Upper St. Lucie 1403 1.22 0.197 8.9

Indian River 

Lagoon

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Upper Mosquito 

Lagoon 1501 1.1 0.05 3.6

Lower Mosquito 

Lagoon 1502 1.3 0.06 7.0

Banana River 1503 1.6 0.06 9.9

Upper Indian River 

Lagoon 1504 1.4 0.06 10

Upper Central 

Indian River 

Lagoon 

1505 1.3 0.06 11

Lower Central 

Indian River 

Lagoon

1506 0.8 0.08 8.0

Lower Indian River 

Lagoon 1507 0.8 0.07 5.6

Halifax River

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Upper Halifax 

River 1601 1.1 0.18 8.8

Lower Halifax 

River 1602 0.85 0.2 9.7

Guana, Tolomato, 

Matanzas, 

Pellicer

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Pablo Creek 1701

0.6 0.09 6.6

Cabbage Creek 1702

Guana River 1703

Upper Tolomato 

River 1704

Lower Tolomato 

River 1705

Upper Matanzas 

River 1706
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Central Matanzas 

River 1707

Lower Matanzas 

River 1708

Lower St. Johns 

River

SEGMENT SEGMENT ID TN*

(mg/L) TP (mg/L) Chl-a

1

(μg/L)

Lower St. Johns 

River 1801 0.75 0.095 2.5

Trout River 1802 1.09 0.108 3.6

Trout River 1803 1.15 0.074 7.7

Nassau

SEGMENT SEGMENT ID TN*

(mg/L) TP (mg/L) Chl-a

1

(μg/L)

Lower Nassau 1901 0.33 0.113 3.2

Middle Nassau 1902 0.40 0.120 2.4

Upper Nassau 1903 0.75 0.125 3.4

St. Marys River

SEGMENT SEGMENT ID TN*

(mg/L) TP (mg/L) Chl-a

1

(μg/L)

Lower St. Marys 

River 2002 0.27 0.045 3.0

Middle St. Marys 

River 2003 0.44 0.036 2.7

1 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.

* For a given water body, 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.

a) Summary of Approaches (Estuaries)

1) EPA Approach (Estuaries)

EPA used a reference-based approach for estuaries where mechanistic modeling 

predictions and monitored data from the 2002-2009 reference time period showed that 

conditions supported balanced natural populations of flora and fauna. For two estuarine 

systems, St. Joseph Bay and Suwannee River, EPA had sufficient monitoring data 
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Page 95 of 191

available to characterize a reference condition in each of the estuarine segments of the 

systems. For these three estuarine systems, EPA used the 90th percentiles of the 

distribution of monitoring data in each segment to derive numeric criteria. 

In five estuarine systems, monitoring data were not available for each segment 

(Perdido Bay, St. Andrews Bay, Alligator Harbor, Apalachicola Bay, and St. Lucie). EPA 

used mechanistic modeling predicted concentration distributions to characterize the 

reference condition for each of these systems. EPA derived criteria based on the 90th

percentiles of the distribution of mechanistic modeling predictions in each segment to 

derive numeric criteria.

In eleven estuarine systems EPA used monitoring data and/or mechanistic 

modeling predictions to evaluate the three biological endpoints (i.e., water clarity, 

chlorophyll a concentration, and DO) and found that reductions in nutrients were 

insufficient to meet all three of the endpoints. However, EPA determined that these 

estuaries appeared to be supporting balanced natural populations of aquatic flora and 

fauna with regard to nutrients because other conditions in the estuaries significantly 

affected the biological endpoints. In one common example, CDOM and suspended solids 

significantly affect water clarity in the system to the point at which nutrient reductions 

alone were not sufficient to achieve the water clarity target. EPA used mechanistic 

modeling predicted concentration distributions in Choctawhatchee Bay, Ochlocknee Bay, 

Big Bend/Apalachee Bay, Springs Coast, Clearwater Harbor/St. Joseph Sound, Sarasota, 

Charlotte Harbor, Loxahatchee, and Nassau/St. Marys River to characterize the reference 

condition for each of these systems. EPA derived criteria based on the 90th percentiles of 

the distribution of mechanistic modeling data in each segment to derive numeric criteria. 
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For two estuarine systems, Indian River Lagoon and Halifax River, there were not 

mechanistic models available, however, EPA had sufficient monitoring data available to 

characterize a reference condition in each of the estuarine segments of the systems. For 

these two estuarine systems, EPA used the 90th percentiles of the distribution of

monitoring data in each segment to derive numeric criteria.

In four estuarine systems (Pensacola Bay, Tampa Bay, Lake Worth, and St. Johns 

River), EPA used monitoring and mechanistic modeling data to determine that, without 

nutrient load reductions, these systems do not support a balanced natural population of 

aquatic flora and fauna. EPA used mechanistic models to calculate the load reductions 

necessary to meet all three biological endpoints, and derived criteria based on 

mechanistic model predictions using this reduced load. EPA used analysis of monitoring 

data in these estuaries to corroborate and support the proposed criteria, where available. 

For additional details please refer to the TSD (Volume 1: Estuaries, Chapter 2).

Proposed criteria for the Guana, Tolomato, Matanzas, and Pellicer (GTMP) 

estuarine system were based upon nutrient concentrations that were calculated from 

stressor-response analyses of available monitoring data to support the biological 

endpoints, and thus support balanced natural populations of aquatic flora and fauna. In 

these systems, EPA’s analysis of monitoring data indicated that existing nutrient loads 

were unlikely to yield conditions that support balanced natural populations of aquatic 

flora and fauna. In these estuaries, mechanistic model predictions were not available 

because there was insufficient data for model parameterization. For additional details 

please refer to the TSD (Volume 1: Estuaries, Chapter 2).
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Several alternative approaches for deriving numeric criteria for estuaries were 

evaluated and considered by EPA, including submissions from FDEP, three west coast 

National Estuary Programs (Tampa Bay, Sarasota Bay, and Charlotte Harbor), and the St. 

Johns River Water Management District for estuaries within their jurisdiction (St. Johns 

River, Mosquito Lagoon, Tolomato-Matanzas estuary, Halifax River estuary, Indian 

River Lagoon, and Banana River). While some of these approaches reflected different 

segmentation schemes than the ones EPA is proposing, all used multiple biological 

endpoints and analytical methods to determine the current state of the system and derive 

criteria. EPA solicits comments on the alternative approaches described in more detail in 

the following section. Additional details on these submissions are provided in the TSD 

(Volume 1: Estuaries, Chapter 2).

2) Alternative for Tampa Bay 

The Tampa Bay National Estuary Program (TBNEP) has derived numeric criteria 

using stressor-response and reference condition approaches for four main segments 

within Tampa Bay (Old Tampa Bay, Hillsborough Bay, Middle Tampa Bay, and Lower 

Tampa Bay) as well as Boca Ciega Bay, Terra Ceia Bay, and the Manatee River estuary. 

The criteria submitted by TBNEP and proposed by FDEP are expressed as chlorophyll a

concentrations, total nitrogen (TN), and total phosphorus (TP) delivery ratios. 

To get an estimate of seagrass coverage in the Bay, TBNEP first established 1950 

as a benchmark time period. Aerial photographs from 1950 showing seagrass distribution 

were compared to more recent images from 1990. Areas with seagrasses present in 1950, 

but absent in 1990, were designated as potential restoration sites. Areas that were 

supporting seagrasses in 1990 were designated as protection sites, while locations where 
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no seagrass could be supported due to major physical alterations were noted as nonrestorable areas and removed from the target analysis. The final seagrass areal target for 

the Bay was based on 95% of the seagrass acreage of the restoration and protection area 

combined. Depth targets were established using a conservative estimate of the deep edge 

of the seagrasses from 1950 coverage. Light requirements of seagrasses were determined 

using data from 1985-1994 and were established as a minimum of 20.5% of subsurface 

light. 

Chlorophyll a concentrations necessary to support the light requirements of 

seagrasses were derived using one of two methods. The first calculates the chlorophyll a

concentrations in each segment necessary to restore seagrasses based on the relationship 

of average monthly chlorophyll a to light availability and the seagrass light requirement 

of 20.5% for healthy growth. Chlorophyll a targets were also developed by calculating 

the average annual chlorophyll a in an estuary segment using data from 1992-1994 (a 

period of time with high and low rainfall during which seagrass was noted to be 

expanding). The lower value of these two methods was used to set the segment-specific 

chlorophyll a target, while a threshold value used for criteria was defined as the loading 

target plus two standard errors above the period of record mean annual chlorophyll a

concentrations in each segment. For Boca Ciega Bay, Terra Ceia Bay and the Manatee 

River estuary, chlorophyll a thresholds were established using the reference condition 

approach.

TN and TP criteria were established for Tampa Bay by calculating the average 

annual segment specific loading for the years 1992-1994, with the exception of Manatee 

River estuary, where the 2003-2007 period was used. The loading was then converted to 
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a segment-specific "Nitrogen Delivery Ratio" or "Phosphorus Delivery Ratio" (the mass 

(load) of TN or TP delivered per volume of water (tons/m3)) during the reference period. 

For more information regarding the derivation of these criteria, please see the 

TSD (Volume 1: Estuaries, Sub-chapter 2.13.9). 

3) Alternative for Sarasota Bay 

FDEP has proposed numeric criteria that were derived by the Sarasota Bay 

National Estuary Program (SBNEP) using a reference condition approach, as well as 

using a stressor-response approach that links nutrients, chlorophyll a, and seagrass extent. 

Numeric nutrient criteria for the greater Sarasota Bay area were proposed for the 

following 5 segments: Palma Sola Bay, Sarasota Bay, Roberts Bay, Little Sarasota Bay, 

and Blackburn Bay. 

To determine seagrass targets, SBNEP analyzed seagrass coverage documented in 

historic and recent aerial surveys and GIS shapefiles. Aerial photos from 1950 were used 

to establish the baseline extent of seagrass in the study area. More recent seagrass areal 

coverage from 2004 to 2006 was determined through analysis of GIS shapefiles based on 

biannual aerial surveys by SFWMD. Areas deemed non-restorable were removed from 

the analysis. The greater of either the historic (1950) or recent (2004-2006) seagrass 

coverage was used as the target in each segment (excluding Little Sarasota Bay which 

used recent coverage).

SBNEP determined that recent seagrass coverage is meeting established targets, 

indicating that corresponding chlorophyll a concentrations and resultant water clarity are 

also protective of the seagrass in each estuary segment. Based on this assessment, 

SBNEP calculated the segment-specific annual arithmetic mean of chlorophyll a
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concentrations from 2001-2005. To allow for some variation in water quality and 

seagrass coverage, SBNEP recommended criteria be based on a chlorophyll a threshold, 

that is the sum of the target and standard deviation around the mean annual chlorophyll a

concentration in each segment.

To derive TN concentration criteria for each segment in Roberts Bay, Little 

Sarasota Bay, and Blackburn Bay, SBNEP first regressed seasonal TN concentration 

against chlorophyll a. The chlorophyll a threshold concentration, described earlier, was 

used to define an associated seasonal TN concentration considered protective. Seasonal 

TN concentrations were weighted based on the number of months per season, and from 

these weighted values an annual geometric mean was calculated to derive the TN 

concentration criteria. 

To calculate TN concentrations for Sarasota Bay, color, region of the Bay, and 

season were regressed against the chlorophyll a threshold values. The seasonal TN 

concentrations were weighted based on the number of months per season and from these 

weighted values an annual geometric mean was calculated to derive the TN criteria. 

In Palma Sola Bay, TN concentration threshold values were derived by 

calculating the annual mean TN concentration, by segment, from 2001-2005 and adding 

the standard deviation of the segment-specific annual mean TN concentrations for the 

period of record of data. 

SBNEP calculated TP concentrations for all five segments of Sarasota Bay based 

on the 2001-2005 reference period. TP criteria were calculated by adding the arithmetic 

means of TP concentrations in each segment during the reference period to the standard 

deviation around the mean annual TP concentrations in each segment. For more 
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information regarding the derivation of these criteria, please see page the TSD (Volume 

1: Estuaries, Sub-chapter 2.14.9). 

4) Alternative for Charlotte Harbor 

FDEP has also proposed segment-specific numeric criteria derived by the 

Charlotte Harbor National Estuary Program (CHNEP) based on mean annual 

concentrations. Derivation of the criteria is based on a reference period approach, except 

in the Caloosahatchee River, due to nutrient impairments. In the Caloosahatchee River 

FDEP will apply a TMDL that is currently under development. Seagrass aerial targets 

were derived for CHNEP by establishing historical baseline acreage (1950) and more 

recently surveyed seagrass acreage (1988-2006). Historical coverage was established by 

interpreting aerial photos from 1950 and digitizing the results, as well as using additional 

electronic coverage data. Overall aerial targets for each segment were based on the 

greater of either the baseline acreage or mean of all recent seagrass surveys. Protection 

and restoration areas were also defined for each segment. Protection areas are defined as 

the minimum seagrass area from recent seagrass surveys. Restoration areas are defined as 

the difference between the minimum and maximum seagrass areas from recent surveys. 

CHNEP determined whether recent seagrass coverage is meeting established 

targets based on the presence of restoration areas, as defined earlier. Using this 

assessment, CHNEP calculated the segment-specific threshold criteria values. 

Chlorophyll a criteria for segments with only protection areas are calculated as the 

arithmetic mean of chlorophyll a concentrations from 2003-2007 plus one standard 

deviation of the annual mean chlorophyll a concentrations in the segment during the 

period of record. For restoration areas chlorophyll a criteria are calculated as the 
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arithmetic mean of chlorophyll a concentrations from 2003-2007 plus one-half standard 

deviation of the annual mean chlorophyll a concentrations in the segment during the 

period of record. Chlorophyll a criteria for the Tidal Myakka and Tidal Peace were 

established based on the chlorophyll a values established for the downstream waters.

Criteria for TN and TP concentrations were developed using the reference period 

from 2003-2007. TN and TP concentration criteria were calculated as the arithmetic 

mean of TN or TP concentrations from 2003-2007, plus one standard deviation of the 

annual mean TN or TP concentrations in the segment during the period of record for 

protection areas, or one-half standard deviation for restoration areas. 

For more information regarding the derivation of these criteria, please see the 

TSD (Volume 1: Estuaries, Sub-chapter 2.15.9).

5) Alternative for Clearwater Harbor and St. Joseph Sound

FDEP proposed concentration-based numeric nutrient criteria for each of the three 

open estuarine segments of St. Joseph Sound, Clearwater Harbor North, and Clearwater 

Harbor South using a reference time period, which is a reference condition approach. 

Seagrasses were identified as a critical endpoint to establish nutrient criteria 

because seagrass health depends on water quality and clarity. Historical photography 

from 1942 and 1957 was used to estimate seagrass acreage, which was then compared to 

seagrass acreage in recent studies. Non-restorable areas were also identified and 

accounted for in the comparison. In Clearwater Harbor North and Clearwater Harbor 

South, historical seagrass estimates were used to establish targets. Because of the large 

amount of physical disturbance in St. Joseph Sound since the time period of the historical 

documentation, the target was based on average of the two most recent surveys. 
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Trends in water quality changes over time were then examined by comparing data 

collected from 1992 to 2002 at fixed sites, to probabilistic sampling sites from 2003 to 

2009. By comparing the distribution of chlorophyll a concentrations, FDEP concluded 

that water quality had improved over time. Annual averages for TN and TP in each 

segment were also comparable, signaling that all segments responded similar to changes 

in water quality and tended to co-vary over time. Additionally, both TN and TP loads 

were observed as declining from 2003 to 2008.190 From the results of those analyses and 

because seagrasses are improving throughout the Clearwater Harbor/St. Joseph Sound 

estuary, it was concluded that recent water quality conditions are sufficient to maintain 

full aquatic life uses in the estuary. 

As a result of the analyses described earlier, a reference period of 2003–2009 was 

chosen to establish chlorophyll a targets and thresholds and TN criteria based on annual 

geometric means during the reference period.191 The threshold value proposed by FDEP 

represents a deviation from reference conditions, and the target would be set to support 

the reference conditions. The threshold value was calculated on the basis of statistical 

theory that if TN concentrations in any year were not different from reference period 

conditions, its geometric average value would be lower than the reference period mean + 

1.96 times the standard deviation of the annual geometric averages with known 

confidence.192

For more information regarding the derivation of these criteria, please see the 

TSD (Volume 1: Estuaries, Sub-chapter 2.12.9).

 190 Levy 2010

191 Janicki Environmental 2011

192 Janicki Environmental 2011
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6) Alternative for St. Johns River Water Management District waters

The St. Johns River Water Management District (SJRWMD) outlined proposed 

approaches for several estuaries within their jurisdiction. These included the St. Johns 

River, Mosquito Lagoon, Tolomato-Matanzas estuary, Halifax River estuary, Indian 

River Lagoon, and Banana River. In general, SJRWMD proposed a weight of evidence 

approach employing several analytical techniques to derive numeric criteria for each of 

the systems. The following paragraphs outline the methods proposed for each of these 

systems.

There are currently values for TN, TP, and chlorophyll a developed for the Lower 

St. Johns River (LSJR) to support TMDL and site-specific alternative criterion (SSAC) 

activities in the river. The LSJR is defined as the main stem segments of the river 

between the juncture with the Ocklawaha River and the river mouth at Mayport, with the 

marine portion occurring between Julington Creek and the mouth. The SSAC was 

developed for DO in the marine portion of the river. It was approved by EPA in 2006 and 

is in effect as a WQS. The TMDL established numeric criteria for TN and TP loads in the 

freshwater portion of the LSJR and TN load criteria in the saline portion of the LSJR to 

achieve the marine DO SSAC and protect the statewide standard for DO in the freshwater 

section. The TMDL also established a SSAC for chlorophyll a as biological target to 

reflect TN and TP concentrations, and thereby ensures attainment of the applicable DO 

criteria established in the SSAC for the marine section of the LSJR.

Similar to the modeling approach proposed by EPA for Florida estuaries, TN, TP, 

and chlorophyll a criteria were derived for the LSJR using linked watershed, 
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hydrodynamic, and water quality models. Non-point nutrient inputs from the watershed 

to the river were determined for each sub-basin in the LSJR using the Pollutant Loading 

Screen Model (PLSM), estimates of atmospheric deposition, and estimates of loading 

from tributaries and upstream. Within the river, hydrodynamics were modeled using the 

Environmental Fluid Dynamics Code (EFDC) model and water quality processes were 

modeled using the U.S. Army Corps of Engineers Quality Integrated Compartment 

Model (CE-QUAL-ICM), Version 2. The models were calibrated for the period from 

January 1, 1995 to November 30, 1998. TMDL model scenarios were assessed on an 

annual basis to determine if chlorophyll a levels exceeded the chlorophyll a threshold of 

40 μg/L less than 10% of the time (to prevent undesirable shifts in algal community 

composition).

For Mosquito Lagoon, a suite of five approaches are considered to develop a 

weight of evidence by which numeric criteria can be developed. These approaches are 

based upon one of three relationships; 1) the link between nutrients, phytoplankton 

growth (as shown by chlorophyll a), and the trophic state of a system; 2) the link between 

nutrients, phytoplankton growth (as shown by chlorophyll a), the effects of 

phytoplankton on light attenuation in the water column, and the light requirements of 

seagrasses; or 3) the connection between TP and harmful algal bloom (HAB) occurrence. 

The first and primary approach uses a reference period from 2004-2008 to calculate 

annual median and maximum wet season medians of chlorophyll a, TN, and TP. The 

reference time period was selected because of the low TN, TP, and chlorophyll a

observed during that period; the rainfall amounts during that period were representative 
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of typical rainfall over time; and the Trophic State Index value for that time period was 

greater than 50, which is considered to be "good" (mesotrophy to oligo-mesotrophy). 

The second approach draws upon an optical model linking chlorophyll a to 

previously established light attenuation targets as a way to predict annual median 

chlorophyll a in southern Mosquito Lagoon that would be protective of seagrass and 

serve as a basis for criteria derivation. A third approach derives a TP level that 

corresponds to minimum "bloom" levels of the dinoflagellate Pyrodinium bahamense, the 

common HAB species seen primarily in the southern Lagoon. A fourth line of evidence 

applied to the Mosquito Lagoon is multivariate geometric mean function regression 

models relating TN and TP to chlorophyll a on an annual basis and during the wet 

season. Targets for chlorophyll a are set based on the reference period mentioned earlier 

for the north and central segments and the optical model for the southern segments. The 

final method is based on two general nutrient models.

193 The reference method is used to 

derive the TN, TP, and chlorophyll a, criteria for the Mosquito Lagoon with the other 

four methods providing supporting evidence. Two criteria magnitudes for TN, TP, and 

chlorophyll a are presented; one an annual median value and the other a wet season (JulySeptember) median value. 

The approaches used for the Indian River Lagoon (IRL) and Banana River 

Lagoon (BRL) are similar to those used for Mosquito Lagoon. The approaches are based 

upon a weight of evidence relying on two general ecological relationships: 1) the link 

between nutrients, phytoplankton growth (as shown by chlorophyll a), and the trophic 

 193 Steward, J.S., and E.F. Lowe. 2010. General empirical models for estimating nutrient load limits for 

Florida’s estuaries and inland waters. Limnology and Oceanography 55(1): 433-445.

Dettmann, E. H, 2001. Effect of water residence time on annual export and denitrification of nitrogen in 

estuaries: A model analysis. Estuaries 24, 481-490.
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state of a system; 2) the link between nutrients, phytoplankton growth (as shown by 

chlorophyll a), the effects of phytoplankton on light attenuation in the water column, the 

light requirements of seagrasses, and the previously established depth limit for 

seagrasses. The influence of TP on HAB events is also discussed as an ancillary line of 

evidence. As a first line of evidence loading limits are derived based on analyses done for 

TMDLs in 2009. The loading limits were established using regression models that regress 

seagrass depth limits targets against loading of TN and TP.194 The second method used 

annual medians of data from reference segments that meet desired depth thresholds 

established by the TMDL analyses. The third approach relies upon an optical model 

similar to the one described earlier for the Mosquito Lagoon using data from 1996-2007. 

A model was built for each of the sub-lagoons: the BRL, North IRL, and Central IRL 

(divided into Sebastian and South Central reaches). An optical model is in development 

for the North Central reach. The fourth approach also applies two general models to data 

specific to the IRL and BRL.195 Where the Dettmann (2001) model could not be used to 

predict TN concentrations, a TN:TP ratio for the given sublagoon was applied to the TP 

limit to get TN limits. The fifth approach relies upon the relationship between HAB 

occurrence and TP concentrations. Targets for chlorophyll a are presented as a range of 

values established using the optical model approach and the reference segment approach. 

Proposed TN and TP loading criteria are based on the loading limits established using the 

TMDL analyses. Primary proposed TN and TP criteria concentrations are calculated 

 194 Steward J.S., R.V. Virnstein, L.J. Morris, and E.F. Lowe. 2005. Setting Seagrass Depth, Coverage, and 

Light targets for the Indian River Lagoon system, Florida. Estuaries, No.6, p.923-935.

195 Steward, J.S., and E.F. Lowe. 2010. General empirical models for estimating nutrient load limits for 

Florida’s estuaries and inland waters. Limnology and Oceanography 55(1): 433-445.

Dettmann, E. H, 2001. Effect of water residence time on annual export and denitrification of nitrogen in 

estuaries: A model analysis. Estuaries 24, 481-490.
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based on the reference segment method. Alternate criteria are proposed using a 

convergence of the concentrations calculated by the reference segment method and 

general models. Two criteria magnitudes are proposed, one for an annual median and the 

other for a wet season (June-October) monthly maximum.

The SJRWMD proposed criteria for the Tolomato and Matanzas Estuary (TME) 

using a weight of evidence approach and methods similar to those used in the other 

estuaries. TN and TP concentrations and chlorophyll a target concentrations are based on 

an approach that analyzes water quality and estimated current loading during a reference 

period from 2000-2009. The period of reference was selected based on a desirable TSI 

score (<50), rainfall amounts typical of average conditions, and completeness of the data 

record. Criteria magnitudes are proposed as an annual median or mean and a maximum 

wet season (June-September) median or mean. The reference period approach of criteria 

derivation for the TME is supported by an additional line of evidence using regression 

analyses of chlorophyll a versus TN and TP. Target chlorophyll a values are based on the 

reference period analyses. The general nutrient models of Steward and Lowe (2010) and

Dettmann (2001) are also used as an additional method by which to estimate loading 

limits and concentrations associated with those limits.

The SJRWMD also derived criteria for the Halifax River Estuary. SJRWMD 

derived criteria using three methods. The first is a reference condition based on the period 

from 2000-2008. This period is selected because of the low TN levels compared to the 

previous decade, the low chlorophyll a concentrations during the period which are 

consistent with chlorophyll a targets established for other estuaries throughout the State, 

and the "good" trophic status shown by TSI values less than 50. Concentrations are 
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calculated using annual median concentrations and maximum wet-season median 

concentrations (as the highest monthly values from July-September) of TN, TP, and 

chlorophyll a. Simple linear regressions are used as a second line of evidence to calculate 

TN and TP criteria based on chlorophyll a targets established by the reference period 

calculations. The general nutrient models of Steward and Lowe (2010) and Dettmann 

(2001) are used as a final method by which to estimate loading limits and concentrations 

associated with those limits. Proposed loading and concentration criteria for the North 

Halifax River Estuary are based on the loading and concentration estimates of the general 

nutrient models, with estimates of loadings from wastewater treatment facilities in the 

estuary removed to represent reference conditions. The current estimated concentrations 

(ca. 2004) of TN and TP based on the reference approach are proposed as criteria for the 

South Halifax River Estuary. Target chlorophyll a values for both segments are 

calculated using the reference period approach.

EPA is also considering the use of approaches outlined in Steward et al. (2005) to 

derive criteria in Indian River Lagoon. In particular EPA is considering using the depth 

of colonization within reference segments as “upper restoration depths” and the highest 

value observed for a specific segment as a minimum target for that segment. For more 

information regarding the derivation of these criteria, please see the TSD (Volume 1: 

Estuaries, Sub-chapter 2.18.9 (Indian River Lagoon), 2.19.9 (Halifax River), 2.20.9 

(GTMP), and 2.21.9 (St Johns River)). 

7) Request for Comment on Proposed and Alternative Approaches

EPA believes that the approach developed for each estuarine system is 

appropriate, scientifically defensible, and results in numeric values that translate the 
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State’s current narrative nutrient criteria to ensure that nutrient concentrations of a body 

of water do not cause an imbalance in natural populations of aquatic flora or fauna that 

will, in turn, protect Class II and III designated waters in the State of Florida. EPA 

requests comment on this system-specific approach and the derived numeric criteria, as 

well as additional scientific information that can be used to translate the State’s narrative 

nutrient criteria to provide protection of fish consumption, recreation and the propagation 

and maintenance of healthy, well-balanced population of fish and wildlife in Florida’s 

Class II and III estuarine waters. 

In addition, EPA requests comment on the alternate approaches that were 

submitted by the NEPs and proposed by FDEP for Tampa Bay, Sarasota Bay, Charlotte 

Harbor, Clearwater Harbor, and St. Joseph Sound, as well as the alternative approaches 

submitted by the St. Johns River Water Management District for waters under their 

jurisdiction. Specifically, EPA requests comment on the scientific defensibility of these 

approaches as well as their ability to result in numeric values that will protect Class II and 

III designated waters in the State of Florida.

b) Proposed Criteria Duration and Frequency (Estuaries)

For the chlorophyll a, TN, and TP criteria for estuarine waters, the criterionmagnitude values (expressed as a concentration) provided in Table III.B-1, the criterionduration (or averaging period) is specified as annual, and the criterion-frequency is 

specified as no more than once every three years. EPA is proposing criteria duration of a 

year, in which sampled nutrient concentrations are summarized as annual geometric 

means, because annual average concentrations are directly related to annual nutrient 
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loading to the waterbody.196 EPA is proposing criteria frequency as a no-more-than-onein-three-years excursion frequency. EPA has determined that this frequency of excursions 

will not result in unacceptable effects on designated uses as it will allow waterbodies 

enough time to recover from occasionally elevated levels of nitrogen and phosphorus 

concentrations. These duration and frequency components of the criteria are identical to 

those utilized in the Inland rule (40 CFR 131.43), which will add consistency to the 

implementation of these criteria with those established in the previous rulemaking. EPA 

requests comment on the frequency and duration components of these criteria regarding 

their ability to ensure protection of the designated uses of these waters. 

c) Proposed DPVs (Estuaries)

EPA is proposing a rule that includes numeric criteria for streams in Florida to 

protect the estuarine waterbodies that ultimately receive nitrogen and phosphorus 

pollution from the watershed. These numeric criteria, which EPA refers to as 

Downstream Protection Values, or DPVs, will apply at the point of entry into the estuary, 

also referred to as the “pour point.” If the DPV is not attained at the point of entry into 

the estuary, then the collective set of streams in the upstream watershed does not attain 

the DPV, for purposes of CWA section 303(d). 

The Agency is proposing a rule that includes three approaches for setting TN and 

TP DPVs:

1. Water quality simulation models,

 196 Boyton, W.R. J.D. Hagy, L. Murray, C.Stokes, and W.M. Kemp. 1996. A comparative anlaysis of 

eutrophication patterns in a temperate coastal lagoon. Estuaries 19:406 – 421.
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2. Ambient water quality data associated with the pour point, coincident 

in time with the data record for which the downstream receiving 

estuary segment TN and TP criteria were developed, and 

3. The estuary segment TN and TP criteria to which the freshwater 

stream or canal discharges. 

The Agency’s intention in proposing all three approaches is to provide a range of 

methods for deriving TN and TP DPVs that reflect the degree of data and scientific 

information available. For the purpose of deriving DPVs EPA believes that the use of 

mechanistic models is the most refined method to define a concentration target at the 

pour point to support the attainment of healthy, balanced populations of aquatic flora and 

fauna. These three approaches are briefly described below. A more detailed description of 

the approaches, as well as examples of the TN and TP DPV calculations using the three 

approaches, is provided in the technical support document.

EPA employed the first approach where water quality simulation models were 

available and used to derive numeric nutrient criteria. Using the model simulations, EPA 

was able to derive DPVs from the modeled nutrient loads entering the estuaries that met 

the biological endpoints, and thus supported designated uses for that estuary. Employing 

the same modeling scenario used to derive the estuarine criteria, the DPVs were based on 

the calibrated watershed model scenario used in deriving estuarine criteria. Similar to the 

estuary criteria, the DPVs were calculated by computing annual geometric mean TN and 

TP concentrations that correspond with the modeled loads at the pour point of each 

tributary for each of the years 2002 through 2009. Because EPA established that model 

interpretations of existing data met all biological endpoints EPA inferred that freshwater 
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loads during this time period supported healthy conditions in the estuary. Therefore EPA 

selected the upper bound (i.e., the 90th percentile) of modeled loads as the DPV.

EPA employed the second approach to calculate DPVs where estuary criteria 

were not derived using water quality simulation models, and where the estuary is 

currently meeting criteria. In these areas, EPA calculated reference-based DPVs using 

water quality data at the pour point of the freshwater streams, coincident in time with the 

data record for which the downstream receiving estuary segment TN and TP criteria were 

calculated. A reference-based approach for computing DPVs was used because the 

downstream receiving estuary segment currently supports biological endpoints. Thus, the 

nutrient concentrations occurring at, and the nutrient loads passing through, the pour 

point over the data record used to show that the estuary is supporting the endpoints are 

protective of the downstream receiving estuary segment. EPA calculated DPVs in these 

areas using the same mathematical approach used to calculate the downstream estuary 

segment TN and TP criteria to prevent calculating a DPV using upstream water quality 

data that coincided with a documented downstream impact (e.g., 303(d) listing for 

nutrients in the estuary segment) and to ensure mathematical consistency between the 

approaches. 

The Agency’s third approach for setting DPVs is to use the downstream receiving 

estuary segment criteria as the DPVs. Such an approach may be appropriate where water 

quality simulation models and water quality data are not available.

EPA is requesting comment on the scientific defensibility of these three proposed 

approaches for determining concentrations of TN and TP result in attainment and 

maintenance of the estuarine criteria. 
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d) EPA Approach and Criteria for Tidal Creeks

Tidal creeks are small sub-estuaries that exhibit a wide range of salinity zones 

typical of larger estuaries, albeit on a smaller scale. Tidal creeks receive freshwater flow 

from streams and groundwater, similar to estuaries, but have small drainage areas and 

less developed drainage systems. Tidal creeks may be dominated by mangroves and other 

wetland vegetation with no freshwater stream inputs, and serve as conduits for tidal water 

to enter and leave wetland areas. Water quality and biological conditions are different in 

tidal creeks compared to more open estuarine systems due to small drainage areas, 

narrow stream channels, shallow depths, and the influence of adjacent marsh and 

mangrove habitats. They are important spawning and nursery areas for aquatic life in 

adjacent estuary and coastal systems. 

EPA concluded that there were insufficient data and research to develop criteria 

specifically for tidal creeks. The Agency proposes to derive numeric criteria for tidal 

creeks using the criteria developed for adjacent freshwater and estuarine segments. If the 

mean chloride concentration of the tidal creek is < 1,500 mg/L, the TN and TP criteria of 

the adjacent freshwaters segment (as defined in 40 CFR 131.43) would be used. If the 

mean chloride concentration of the tidal creek is > 1,500 mg/L, the TN and TP criteria of 

the adjacent estuary segment (as defined in Section III.B of this proposed rulemaking) 

would be used. EPA did not establish chlorophyll a criteria for freshwater streams in the

December 2010 final rule, Water Quality Standards for the State of Florida’s Lakes and 

Flowing Waters (40 CFR 131.43).The alternate option is to derive values for tidal creeks 

based on the mean salinities for the tidal creek, which would then be used to interpolate 

TN and TP concentrations between freshwater and estuarine criteria from adjacent 
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freshwater and estuarine segments. Criteria would be derived by this method where there 

were sufficient salinity data to allow for interpolation. The calculation used to interpolate 

TN and TP concentrations between freshwater and estuarine segments based on salinity is 

provided in detail in the TSD (Volume 1: Estuaries, Sub-chapter 3.1). 

EPA is soliciting comment on the proposed option and the alternative, as well as 

other scientific information that can be used to translate the State’s narrative nutrient 

criteria to provide protection of fish consumption, recreation, and the propagation and 

maintenance of healthy, well-balanced populations of fish and wildlife in Florida’s tidal 

creeks. 

e) EPA Approach and Criteria for Marine Lakes

Marine lakes are coastal lakes and ponds with ground-water or intermittent 

surface water connections to marine water. They do not have a permanent surface 

connection to tidal waters. They are small and shallow, and generally round or elliptical 

in shape reflecting their formation as depressions that became isolated from marine 

waters by sand and dune formation. Some marine lakes are stratified by a salinity 

gradient where a freshwater layer at the surface is separated from a denser saline layer 

below. Similar to inland lakes, marine lakes are generally oligotrophic under undisturbed 

conditions with low nutrient concentrations and low productivity. Their oligotrophic 

nature and stratification make them susceptible to the adverse effects of nutrient 

enrichment. EPA analyzed the data from over 50 marine lakes in Florida and found that 

chlorophyll a responded to nutrient enrichment in a similar fashion, based on color and 

alkalinity, as inland lakes. Details and supporting documentation are provided in the TSD 

(Volume 1: Estuaries, Sub-chapter 3.2). 
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EPA has determined that the Inland Rule criteria developed for inland lakes are 

applicable to marine lakes due to similarities in trophic condition and chlorophyll a 

response to nutrient concentrations. The criteria EPA proposes to use for marine lakes are 

those found in 40 CFR 131.43 and below in Table III.B-2.

Table III.B-2. EPA’s Proposed Numeric Criteria for Florida’s Marine Lakes

Long Term Average Lake 

Colora and Alkalinity

EPA Final 

Chl-a

b,*

μg/L

EPA Final TN and TP Criteria

[Range]

TN

mg/L

TP

mg/L

Colored lakesc 20 1.27

[1.27-2.23]

0.05

[0.05-0.16]

Clear lakes, high 

alkalinityd

20 1.05

[1.05-1.91]

0.03

[0.03-0.09]

Clear lakes, low 

alkalinitye

6 0.51

[0.51-0.93]

0.01

[0.01-0.03] a Platinum-cobalt units (PCU) assessed as true color free from turbidity b Chl-a is defined as corrected chlorophyll, or the concentration of chl-a remaining

after the chlorophyll degradation product, phaeophytin a, has been subtracted from the uncorrected

chl-a measurement. c Long-term color > 40 PCU and alkalinity > 20 mg/L CaCO3 d Long-term color ≤ 40 PCU and alkalinity > 20 mg/L CaCO3 e Long-term color ≤ 40 PCU and alkalinity ≤ 20 mg/L CaCO3

* For a water body, the annual geometric mean of chl-a, TN or TP concentrations shall

not exceed the applicable criterion concentration more than once in a three-year period.

EPA is soliciting comment on the application of Inland Rule lake criteria to 

marine lakes.

C. Proposed Numeric Criteria for Coastal Waters

1. Introduction 

Coastal waters are defined in this proposed rulemaking as marine waters that start 

at the land margin and extend up to three nautical miles from shore, with chloride 

concentrations greater than 1,500 mg/L, excluding estuaries. Unlike estuaries, which are 
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commonly dominated by freshwater flows and can be organized within watershed 

boundaries, coastal waters have open coastal boundaries and localized influences near the 

estuary/coastal boundary (i.e., estuary pass). 

EPA is proposing criteria for coastal waters using satellite remote sensing to 

derive chlorophyll a, where possible. EPA is proposing to use a different approach to 

derive numeric criteria for marine waters in south Florida, including the Florida Keys and 

Dry Tortugas, because significant bottom reflectance in the region confounds derivation 

of chlorophyll a from satellite remote sensing (chlRS-a) and extensive monitoring data are 

available to use in deriving criteria. EPA is also proposing an alternative approach for 

coastal criteria derivation in the Big Bend region (between St. Joseph Bay and Anclote 

Bay) based on mechanistic modeling because seagrass beds within the coastal waters and 

CDOM export from rivers confound interpretation of satellite data and derivation of 

chlRS-a. Proposed criteria for Big Bend region and south Florida marine areas are 

discussed in subsections III.B and III.D, respectively. 

2. Proposed Numeric Criteria (Coastal Waters)

EPA is proposing numeric criteria for remotely sensed chlorophyll a in 74 

segments (see the TSD, Volume 2: Coastal Waters, section 1.3 for a map showing the 

locations of the segments) in three coastal regions of Florida classified as Class III waters 

under Florida law (Section 62-302.400, F.A.C.) (Table III.C-1). 

Table III.C-1. EPA’s Proposed Numeric Criteria for Florida’s Coastal Waters
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Coastal Region Coastal 

Segment197 Approximate Location ChlorophyllRS-a1

* (mg/m3)

Panhandle

1 AL border 2.41

2 Pensacola Bay Pass 2.57

3 1.44

4 1.16

5 1.06

6 1.04

7 1.14

8 Choctawhatchee Bay Pass 1.23

9 1.08

10 1.09

11 1.11

12 1.18

13 1.45

14 St. Andrew Bay Pass 1.74

15 St. Joseph Bay Pass 2.75

16 2.39

17 Southeast St. Joseph Bay 3.47

West Florida 

Shelf

18 5.43

19 4.80

20 4.24

21 3.96

22 Tampa Bay Pass 4.45

23 3.37

24 3.25

25 2.95

26 2.79

27 2.98

28 3.24

29 Charlotte Harbor 4.55

30 4.22

31 3.67

32 4.16

33 5.70

34 4.54

35 4.03

36 Fort Myers 4.61

Atlantic Coast

37 Biscayne Bay 0.92

38 0.26

39 0.26

40 0.24

41 0.21

42 0.21

43 0.20

44 0.20

45 0.21

46 0.25

47 0.57

48 St. Lucie Inlet 1.08

 197 Please see TSD for location of Coastal Segments
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Coastal Region Coastal 

Segment197 Approximate Location ChlorophyllRS-a1

* (mg/m3)

49 1.42

50 1.77

51 1.55

52 1.44

53 1.53

54 1.31

55 1.40

56 1.80

57 Canaveral Bight 2.73

58 2.33

59 2.28

60 2.06

61 1.92

62 1.76

63 1.72

64 2.04

65 1.92

66 1.86

67 1.95

68 2.41

69 2.76

70 2.80

71 3.45

72 Nassau Sound 3.69

73 3.78

74 Georgia border 4.22 1 ChlorophyllRS-a is remotely sensed calculation of chlorophyll a concentrations. 

* For a given water body, the annual geometric mean of the chlorophyll a concentration shall not exceed 

the applicable criterion concentration more than once in a three-year period.

a) Summary of Approaches

1) EPA Approach (Coastal Waters)

EPA conducted a comprehensive review of water body-specific water quality and 

impairment information as detailed in Section III.A.3.a. EPA determined through this 

review that at most times, Florida coastal waters appear to be supporting balanced 

populations of flora and fauna. Therefore criteria are proposed for coastal waters using a 

reference condition approach and satellite remote sensing imagery to derive protective 

criteria for chlorophyll a using a dataset that has been screened for times of K. brevis

bloom events. 
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b) Request for Comment on Proposed Approach

EPA believes that the approach that EPA has developed for these coastal waters is 

appropriate, scientifically defensible, and results in numeric values that translate the 

State’s current narrative nutrient criterion that will, in turn, protect Class III designated 

waters in the State of Florida. EPA requests comment on this approach and the derived 

numeric criteria, as well as additional scientific information that can be used to translate 

the State’s narrative nutrient criteria to provide protection of fish consumption, recreation 

and the propagation and maintenance of healthy, well-balanced population of fish and 

wildlife in Florida’s Class III coastal waters. 

c) Proposed Criteria Duration and Frequency (Coastal Waters)

For the chlorophyll a criteria for coastal waters, the criterion-magnitude values 

(expressed as a concentration) provided in Table III.C-1, the criterion-duration (or 

averaging period) is specified as annual, and the criterion-frequency is specified as no 

more than once every three years. EPA is proposing criteria duration of a year, in which 

sampled nutrient concentrations are summarized as annual geometric means, because 

annual average concentrations are directly related to annual nutrient loading to the 

waterbody.198 EPA is proposing criteria frequency as a no-more-than-one-in-three-years 

excursion frequency. EPA has determined that this frequency of excursions will not result 

in unacceptable effects on designated uses as it will allow waterbodies enough time to 

recover from occasionally elevated levels of nitrogen and phosphorus concentrations. 

 198 Boyton, W.R. J.D. Hagy, L. Murray, C.Stokes, and W.M. Kemp. 1996. A comparative anlaysis of 

eutrophication patterns in a temperate coastal lagoon. Estuaries 19:406 – 421.
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These duration and frequency components of the criteria are identical to those utilized in 

the Inland rule (40 CFR 131.43), which will add consistency to the implementation of 

these criteria with those established in the previous rulemaking. EPA requests comment 

on the frequency and duration components of these criteria regarding their ability to 

ensure protection of the designated uses of these waters. 

D. Proposed Numeric Criteria for South Florida Marine Waters 

1. Introduction

For purposes of this proposed rule, EPA is referring to south Florida marine 

waters as marine waters in the South Florida Nutrient Watershed Region.199 EPA 

delineated the South Florida Region as the flowing freshwaters south of Lake 

Okeechobee, the Caloosahatchee River watershed, and the St. Lucie River watershed. 

Some of the significant land management units within the South Florida Region include 

the Everglades Agricultural Area, the Loxahatchee National Wildlife Refuge (Water 

Conservation Area 1), Water Conservation Areas 2 and 3, Big Cypress National Preserve, 

Everglades National Park, Biscayne Bay National Park, and the Florida Keys National 

Marine Sanctuary. A map of the South Florida Region can be found in the TSD (Volume 

3: South Florida’s Estuaries, Coastal Waters, and Inland Flowing Waters, Chapter 1). 

EPA is proposing numeric criteria collectively for these southern marine waters 

because of their unique physical, chemical and biological properties. They are 

substantially different from other Florida coastal systems in part because South Florida 

 199 This is consistent with the classification used in previous EPA 

rulemaking (see EPA. 2010. Technical Support Document for U.S. EPA’s Final Rule for 

Numeric Criteria for Nitrogen/Phosphorus Pollution in Florida’s Inland Surface Fresh Waters).
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lacks the major rivers that are typical of watersheds throughout the State. They have 

unique freshwater sources (e.g., Everglades) and interactions with ocean waters. Nutrient 

sources in the watersheds that discharge into south Florida marine waters are typical of 

other areas in Florida and include runoff from developed (agricultural, urban) and 

undeveloped (wetlands and forests) lands, and discharges from wastewater treatment 

plants. However, the flow paths that transport nutrients to these waters are unique and 

varied and include managed surface flows (canals), seepage from groundwater, 

circulation of ocean water, and direct atmospheric deposition. 

2. Proposed Numeric Criteria (South Florida Marine Waters)

For each south Florida marine system, the ecological status of phytoplankton, 

seagrass, mangrove, hardbottom, and macroalgal communities was evaluated with respect 

to impairments. EPA used information from the scientific literature, EPA reports, and 

existing State water quality data to perform this assessment. Based on this extensive 

review, EPA is confident that the screened data set represents times at which the marine 

systems are supporting balanced natural populations of aquatic flora and fauna. Hence, 

EPA is considering a segment-specific reference approach based on these least-impaired 

sites to derive numeric TN, TP, and chlorophyll a criteria for south Florida marine 

waters. EPA is proposing TN, TP, and chlorophyll a criteria for 40 segments for six south 

Florida marine systems (Table III.D-1). 

Table III.D-1. EPA’s Proposed Numeric Criteria for South Florida Marine Waters

S. Coastal System Segment 

Code Segment Name TN*(mg/L)

TP* 

(mg/L)

Chlorophyll 

a*1 (μg/L)

Biscayne Bay

NNB Northern North Bay 0.33 0.012 1.82

SNB Southern North Bay 0.31 0.010 1.04

NCI North Central Inshore 0.33 0.008 0.47

SCI South Central Inshore 0.53 0.008 0.41

SCM South Central Mid-Bay 0.40 0.008 0.36

SCO South Central Outer-Bay 0.27 0.007 0.28
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CS Card Sound 0.38 0.007 0.38

Florida Bay

MBS Manatee-Barnes Sound 0.74 0.010 0.77

ECFB East Central Florida Bay 0.89 0.009 0.69

CFB Central Florida Bay 1.47 0.025 3.17

SFB South Florida Bay 0.89 0.011 1.35

WFBN West Florida Bay-North 0.45 0.024 2.98

WFBC West Florida Bay-Central 0.63 0.020 2.06

WFBS West Florida Bay-South 0.34 0.012 1.04

NFB North Florida Bay 0.87 0.015 1.09

CL Coastal Lakes 1.61 0.050 10.22

Florida Keys

FKN Florida Keys-North 0.20 0.007 0.28

FKT Florida Keys-Transition 0.21 0.008 0.34

FKS Florida Keys-South 0.23 0.008 0.37

KWOS Key West-Offshore 0.21 0.008 0.39

BKB Back Bay 0.29 0.009 0.39

BKS Back Shelf 0.26 0.012 0.74

MAR Marquesas 0.24 0.009 0.63

DT Dry Tortugas 0.22 0.008 0.43

Whitewater Bay/ 

Ten Thousand 

Islands

WWB Whitewater Bay 1.05 0.029 4.58

PD Ponce de Leon 0.67 0.026 3.06

SRM Shark River Mouth 1.15 0.027 2.49

CTHB Coastal Harney-Broad River 0.85 0.041 5.44

LMB Lostman Bay 0.90 0.027 4.02

IWW Internal Waterways 0.77 0.037 5.02

GI Gulf Islands 0.54 0.040 3.81

BLK Black River 0.47 0.056 4.21

Pine Island/ 

Rookery Bay

MARC Marco Island 0.37 0.048 5.95

NPL Naples Bay 0.38 0.052 5.22

COCO Cocohatchee 0.55 0.059 6.35

Gulf Shelf GS Gulf Shelf 0.40 0.021 2.88 1 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.

* For a given water body, 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.

a) Alternative Approaches Evaluated by EPA (South Florida Marine Waters)

During EPA’s review of the available scientific data and information for 

derivation of numeric criteria for south Florida's marine waters, EPA also considered 

alternate approaches for criteria derivation. 

As an alternative method to calculate TN, TP, and chlorophyll a criteria using the 

reference approach, the Agency is considering the annual geometric means for TN, TP, 

and chlorophyll a proposed by FDEP and associated segmentation. Additional details are 
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provided in the TSD (Volume 3: South Florida’s Estuaries, Coastal Waters, and Inland 

Flowing Waters, Sub-chapter 1.5). 

b) Request for Comment on Proposed and Alternative Approaches

EPA believes that the approach that EPA has developed for marine waters in 

south Florida is appropriate, scientifically defensible, and results in numeric values that 

translate the State’s current narrative nutrient criteria that will, in turn, protect these Class 

II and III designated waters in the State of Florida. EPA requests comment on this 

approach and the derived numeric criteria, as well as additional scientific information that 

can be used to translate the State’s narrative nutrient criteria to provide protection of fish 

consumption, recreation and the propagation and maintenance of healthy, well-balanced 

population of fish and wildlife in south Florida’s Class II and III marine waters. 

In addition, EPA requests comment on the alternate approach of using FDEP’s 

proposed segmentation and associated criteria. Specifically, EPA requests comment on 

the scientific defensibility of this alternative approach as well as its ability to result in 

numeric values that will protect Class II and III designated waters in the State of Florida.

c) Proposed Criteria Duration and Frequency (South Florida Marine Waters)

For the TN, TP, and chlorophyll a criteria for south Florida marine waters, the 

criterion-magnitude values (expressed as a concentration) provided in Table III.D-1, the 

criterion-duration (or averaging period) is specified as annual, and the criterion-frequency 

is specified as no more than once every three years. EPA is proposing criteria duration of 

a year, in which sampled nutrient concentrations are summarized as annual geometric 
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means, because annual average concentrations are directly related to annual nutrient 

loading to the waterbody.200 EPA is proposing criteria frequency as a no-more-than-onein-three-years excursion frequency. EPA has determined that this frequency of excursions 

will not result in unacceptable effects on designated uses as it will allow waterbodies 

enough time to recover from occasionally elevated levels of nitrogen and phosphorus 

concentrations. These duration and frequency components of the criteria are identical to 

those utilized in the Inland rule (40 CFR 131.43), which will add consistency to the 

implementation of these criteria with those established in the previous rulemaking. EPA 

requests comment on the frequency and duration components of these criteria regarding 

their ability to ensure protection of the designated uses of these waters. 

d) Proposed DPVs (South Florida Marine Waters)

In this proposed rule, attainment and maintenance of the water quality standards 

of downstream waters in South Florida is ensured through establishment of a downstream 

protection value (DPV). The applicable criteria for flowing waters in south Florida that 

impact the downstream south Florida marine waters consist of the DPV, which is a 

concentration value at the point of entry into marine waters that results in attainment of 

the south Florida marine criteria. 

EPA selected the point of entry into the south Florida marine waters, also referred 

to as the “pour point,” as the location to identify DPVs because the marine waters 

respond to the input from the pour point and all contributions from the network of 

flowing waters above this point in a canal or stream basin affect the water quality at the 

 200 Boyton, W.R. J.D. Hagy, L. Murray, C.Stokes, and W.M. Kemp. 1996. A comparative analysis of 

eutrophication patterns in a temperate coastal lagoon. Estuaries 19:406 – 421.
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pour point. The canal basin concept is similar to that of a watershed in less managed 

waters and is used by the South Florida Water Management District (SFWMD) to define 

31 canal basins in South Florida. 

If the DPV is not attained at the point of entry into the estuary, then the collective 

set of streams in the upstream watershed does not attain the DPV, for purposes of CWA 

section 303(d). 

To calculate DPVs in south Florida EPA is proposing the following approaches 

(also see subsection III.B.2.c. for additional information): 

1. Ambient water quality data associated with the pour point coincident in 

time with the data record for which the downstream receiving estuary 

segment TN and TP criteria were developed, and 

2. The estuary segment TN and TP criteria to which the freshwater stream 

or canal discharges.

EPA is requesting comment on whether these approaches for determining 

concentrations of TN and TP will result in attainment and maintenance of the south 

Florida marine criteria. 

E. Proposed Numeric Criteria for South Florida Inland Flowing Waters

1. Proposed Numeric Criteria (South Florida Inland Flowing Waters) 

For purposes of this proposal, “south Florida Inland flowing waters” refers to 

Class I and Class III surface waters with chloride concentrations at the surface less than 

1,500 mg/L in a defined channel, including streams and canals. In general, these waters 

are located within the boundaries of the Southern Florida Coastal Plain south of Lake 
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Okeechobee, the Caloosahatchee River watershed, and the St. Lucie watershed and are 

bounded by the estuarine/marine waters of the Gulf of Mexico and Atlantic Ocean to the 

east, south, and west. This area contains more than 1,700 miles (2,736 km) of canals, 

dikes, and levees that control the movement of freshwater in south Florida. South Florida 

inland flowing waters include the large wetland ecosystem of the Everglades. A map 

showing this region is provided in the TSD (Volume 3: South Florida’s Estuaries, Coastal 

Waters, and Inland Flowing Waters, Chapter 3).

EPA is proposing criteria for TN and TP expressed as downstream protection 

values for 23 pour points for estuarine systems in south Florida, where surface waters 

discharge into estuaries or marine waters (Biscayne Bay, Florida Bay, Southeast Coast 

marine waters, and Southwest Coast marine waters). The applicable criteria for flowing 

waters in south Florida, outside the EvPA and the EAA, consist of the marine water 

DPVs (See subsection III.D.2.d. for more information).

The numeric nutrient criteria that EPA is proposing for south Florida inland 

flowing waters do not apply to flowing waters (canals) within the Everglades Protection 

Area (EvPA) or the Everglades Agricultural Area (EAA). There is an existing TP 

criterion of 0.010 mg/L (10 ppb) that currently applies to the marshes and adjacent canals 

within the EvPA (Section 61-302.540, F.A.C.). EPA approved that TP criterion in 2005 

as protective of the waters in the EvPA. EPA’s approval was upheld by the U.S. District 

Court in Miccosukee Tribe of Indians, et al. v. EPA.

201 For this proposal, EPA has 

determined that the existing TP criterion continues to be protective of the designated uses 

of the flowing waters in the EvPA and that no additional numeric nutrient criteria are 

 201 Miccosukee Tribe v US EPA, 105 F.3d 599 (11th Cir. 1997)
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necessary at this time for the EvPA. While the existing TP criterion does not apply 

directly to the flowing waters of the EAA, EPA has also determined that the TP criterion 

will serve to be protective of the designated uses of the flowing waters in the EAA. Most 

current flows from the EAA pass through storm water treatment areas (STAs) that have 

been specifically constructed to remove phosphorus from those waters before entering the 

EvPA. The waters discharging from the STAs are subject to CWA discharge permits that 

must include limits as stringent as necessary to meet the 10 ppb TP criterion in the EvPA. 

Reductions of phosphorus upstream of the STAs (i.e., in the EAA) are part of the actions 

necessary to ensure the water discharged from the STAs will meet the TP criterion in the 

EvPA. Based on the combination of the actions that will be necessary to ensure that 

waters from the EAA do not cause an impairment of the downstream waters in the EvPA, 

EPA has determined that the existing TP criterion is the only numeric nutrient criterion 

that is necessary to protect the flowing waters of the EAA as well as the EvPA. 

Development of water quality standards for the EvPA and restoration actions within the 

EAA to attain the TP criterion have been and remain subject to the oversight of two 

federal district courts. EPA believes its determination not to propose additional numeric 

nutrient criteria for these areas also will help facilitate the ongoing restoration efforts in 

the Everglades. 

a) Alternative Approaches Evaluated by EPA (South Florida Inland Flowing 

Waters)

As an alternative, EPA developed protective values for Class I and III waters 

(including canals and streams) in three inland subregions in south Florida (Biscayne, 

Palm Beach, and West) that are outside the EAA and the EvPA. The TN and TP values 
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represent the geometric mean of water quality measurements for waters in those regions 

and the criteria values are based on the frequency of occurrence of nuisance algal blooms 

in these waters, measured by chlorophyll a. Additional details are provided in the TSD 

(Volume 3: South Florida’s Estuaries, Coastal Waters, and Inland Flowing Waters, 

Chapter 3). 

b) Request for comment on the Proposed and Alternative Approaches

EPA believes that both the proposed and alternative approaches that EPA has 

developed for inland flowing waters in south Florida are appropriate, scientifically 

defensible, and result in numeric values that translate the State’s current narrative nutrient 

provision that will, in turn, protect these Class I and III designated waters in the State of 

Florida. EPA requests comment on this approach and the derived numeric criteria, as well 

as additional scientific information that can be used to translate the State’s narrative 

nutrient provision to provide protection of fish consumption, recreation and the 

propagation and maintenance of healthy, well-balanced population of fish and wildlife in 

south Florida’s Class I and II inland flowing waters. 

F. Applicability of Criteria When Final

EPA’s proposed numeric nutrient criteria for Florida’s estuary’s, coastal and 

South Florida flowing waters will be effective for CWA purposes 60 days after 

publication of final criteria and will apply in addition to any other existing CWAeffective criteria for Class I, II or Class III waters already adopted by the State and 

submitted to EPA (and for those adopted after May 30, 2000, approved by EPA). EPA 

requests comment on this proposed effective date. 
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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 II waters provide for the protection of 

shellfish propagation or harvesting. 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. Class I, II and III waters comprise the set of Florida waters that 

meet the goals articulated in section 101(a)(2) of the CWA and the waters for which EPA 

is proposing criteria. 

For water bodies designated as Class I, II and Class III any final EPA numeric 

nutrient criteria will be applicable CWA water quality criteria for purposes of 

implementing CWA programs including permitting under the NPDES program, as well 

as monitoring and assessment based on applicable CWA WQS and establishment of 

TMDLs. The proposed criteria in this rule, if and when finalized, would be 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 

proposed 40 CFR 131.45(d). 

EPA notes that the proposed 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. 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 proposed rule to 

enumerate each of them, nor is it necessary to restate any otherwise applicable 
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requirements. This broad reference to general rules of applicability provides sufficient 

coverage and was used without further elaboration in EPA’s December 6, 2010 final 

Inland criteria promulgation. The Agency is also concerned that addressing some

applications in this proposal and not others may create unnecessary and unintended 

questions, confusion, and uncertainty about the overall application of Florida’s general 

rules.

It is important to keep in mind that no TMDL will be rescinded or invalidated as a 

result of this proposed rule, nor does this proposed 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.

IV. Under What Conditions Will Federal Standards Be Either Not Finalized or 

Withdrawn?

Under the CWA, Congress gave states primary responsibility for developing 

and adopting water quality standards for their navigable waters. (See CWA section 

303(a)-(c)). Although EPA is proposing numeric criteria for estuaries and coastal waters 

in Florida and flowing waters in the South Florida Region, Florida continues to have the 
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option to adopt and submit to EPA numeric criteria for the State’s Class I, Class II and 

Class III waters consistent with CWA section 303(c) and implementing regulations at 40 

CFR 131. Consistent with CWA section 303(c)(4), if Florida adopts and submits numeric 

nutrient criteria and EPA approves such criteria as fully satisfying the CWA before 

publication of the final rulemaking, EPA will not proceed with the final rulemaking for 

those waters for which EPA approves Florida’s criteria. 

Pursuant to 40 CFR 131.21(c), if EPA does finalize this proposed rule, EPA’s 

promulgated water quality standards are applicable water quality standards for purposes 

of the CWA until EPA withdraws those federally-promulgated water quality standards.

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 nutrient criteria that fully meet the 

requirements of section 303(c) of the CWA and EPA’s implementing regulations at 40 

CFR 131.

V. Alternative Regulatory Approaches and Implementation Mechanisms

A. Designating Uses

Under CWA section 303(c)(2)(A), 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) 
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defines “designated uses” as “those uses specified in water quality standards for each 

water body 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 individual surface waters.

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)). EPA’s regulations at 40 

CFR 131 interpret and implement CWA sections 101(a)(2) and 303(c)(2)(A) to require 

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 (referred 

to as uses specified in section 101(a)(2) of the Act), wherever attainable. (See 40 CFR 

131.2; 131.5(a)(4); 131.6(a),(f); 131.10(g),(j)). Where states do not designate uses

specified in 101(a)(2) of the Act, or remove such uses, they must demonstrate that the

uses are not attainable consistent with the use attainability analysis (UAA) provisions of 

40 CFR 131.10, specifically 131.10(g). A state may remove protection for a 101(a)(2) use 

if it can show, based on a UAA consistent with 131.10, that attaining such a designated 

use is not feasible. States may include waters located in the same 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). 
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EPA’s proposed numeric nutrient criteria for estuaries and coastal waters, and 

inland flowing waters in the South Florida Region will apply to those waters designated 

by Florida as Class I (Potable Water Supplies), Class II (Shellfish Propagation or 

Harvesting) or Class III (Recreation, Propagation and Maintenance of a Healthy, WellBalanced Population of Fish and Wildlife). If Florida removes either the Class I, Class II 

and/or Class III designated use for any particular water body ultimately affected by this 

rule, and EPA approves such a removal because it is consistent with CWA section 303(c) 

and regulations at 40 CFR 131, then the federally-promulgated numeric nutrient criteria

would not apply to that water body because it would no longer be designated Class I, II or 

III. Only the water quality criteria associated with the revised designated use would apply 

to that water body.

B. Variances

A variance is a temporary modification to the designated use and associated water 

quality criteria that would otherwise apply to the water body.

202 Variances constitute new 

or revised water quality standards subject to the procedural and substantive requirements 

applicable to removing a designated use.203 Thus, an approvable variance may only be 

granted if it is based on the same factors, set out at 40 CFR 131.10(g), that are required to 

revise a 101(a)(2) designated use through a UAA.

Typically, variances are time-limited, but may be renewed. Temporarily 

modifying the designated use for a particular water body through a variance process 

 202 Water Quality Standards Regulation, 40 C.F.R. Part 131: Advance notice of proposed rulemaking.

USEPA Fed. Reg. 63:129 (July 7, 1998). p. 36741-36806. 203 In re Bethlehem Steel Corporation, General Counsel Opinion No. 58. March 29, 1977 (1977 WL 28245 

(E.P.A. G.C.)).
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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 state should seek a variance instead of a permanent use removal where the 

state believes the water quality standard can be attained at some point in the future. By 

maintaining the designated use, and associated criteria, 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 discharger. All other applicable water quality 

standards not specifically modified by the variance, including any other criteria adopted 

to protect the designated use, remain applicable. State variance procedures, as part of 

state water quality standards, must be consistent with the substantive requirements of 40 

CFR 131. Each variance, as a revised water quality standard, must be submitted to EPA 

for review and approval or disapproval pursuant to CWA section 303(c).

For purposes of this proposal, EPA is proposing 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, Class II or Class III uses as it pertains to any 

federally-promulgated criteria. For this reason, EPA is not proposing a Federal variance 

procedure. 

C. Site-Specific Alternative Criteria

Site-Specific alternative criteria (SSAC) are alternative values to otherwise 

applicable water quality criteria that would be applied on a watershed, area-wide, or 
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water body-specific basis that meet the regulatory test of protecting the water’s

designated use, having a basis in sound science, and ensuring the protection and 

maintenance of downstream water quality standards. SSAC may be more or less stringent 

than the otherwise applicable criteria. In either case, because the SSAC must protect the 

same designated use and must be based on sound science according to 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 additional scientific data and analyses can bring 

increased precision or accuracy to express the necessary concentration of a water quality 

parameter that is protective of the designated use.

In EPA’s 2010 rulemaking for Florida’s lakes and flowing waters outside of the 

South Florida Region, EPA promulgated a procedure whereby EPA’s Region 4 Regional 

Administrator may establish a SSAC after making available the proposed SSAC and 

supporting documentation for public comment. (See 40 CFR 131.43(e)). This procedure 

became effective for CWA purposes on February 4, 2011. Under this provision, any 

entity, including the State, can 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 nutrient criteria is warranted. The Federal SSAC process is separate and distinct 

from the State’s SSAC processes in its water quality standards.

The current Federal SSAC procedure allows EPA to determine that a revised sitespecific chlorophyll a, TN, TP, or nitrate+nitrite numeric criterion should apply in lieu of 

the generally applicable criteria promulgated in the final rule for Florida’s lakes and 

flowing waters where that SSAC is demonstrated to be protective of the applicable 

designated use(s). The promulgated procedure provides that EPA will solicit public 
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comment on its determination. Because EPA’s rule established 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’s granting of variances and 

SSACs in other federally promulgated water quality standards.

204

Consistent with the procedure outlined in 40 CFR 131.43(e) and in the draft 

“Technical Assistance for Developing Nutrient Site-Specific Alternative Criteria in 

Florida” (June 2011), 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 the 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, EPA’s Region 4 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 

 204 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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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 or is not appropriate to 

account for site-specific conditions and make that determination publicly available 

together with an explanation of the basis for the decision.

EPA believes that there is benefit in extending this procedure for EPA adoption of 

Federal SSAC that will adjust the numeric nutrient criteria proposed in this rule. EPA is 

therefore proposing that the same procedure promulgated in 40 CFR 131.43(e) apply to 

estuaries, coastal waters and flowing waters in the South Florida Region. EPA requests 

comment on the following proposed application of the SSAC procedure.

To successfully develop a Federal SSAC for a given estuary, coastal water 

segment, or stream in the South Florida Region, a thorough analysis is necessary that 

indicates how the alternative concentration of TN, TP, or chlorophyll a supports both the 

water body itself and downstream water bodies, where applicable. This analysis should 

have supporting documentation that consists of examining indicators of longer-term 

response to multiple stressors, such as seagrass health, as well as indicators of shorterterm response specific to nitrogen and phosphorus pollution, such as periphyton algal 

thickness or water column chlorophyll a concentrations. In developing a Federal SSAC, it 

is necessary to ensure that values allowed in an upstream water body as a result of a 

SSAC provide for the attainment and maintenance of the water quality standards of 

downstream waters, where applicable.
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EPA is proposing five approaches for developing SSAC for estuaries, coastal

water segments and streams in the South Florida Region that are similar to the four 

approaches EPA finalized in the 2010 rule for Florida’s lakes and flowing waters. The 

first three proposed approaches are replicating the approaches EPA used to develop 

estuary, coastal and south Florida inland flowing water criteria, respectively, and 

applying these methods to a smaller subset of waters or water body segments. To 

understand the necessary steps in this analysis, interested parties should refer to the 

complete documentation of these approaches in the Technical Support Document for this 

proposed rule.

The fourth proposed approach for developing SSAC is to conduct a biological, 

chemical, and physical assessment of water body conditions. A detailed description of the 

supporting rationale must be included in the documentation submitted to EPA. The 

components of this approach could include, but not be limited to, evaluation of seagrass 

health, 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 water body type, with specific components of analysis 

tailored for the situation.

The proposed fifth 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 
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131.11(b)(1)(iii). This approach could potentially include use of mechanistic models or 

other data and information.

D. Compliance Schedules

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, Water Quality-Based Effluent 

Limitations (WQBELs) are effluent limits based on applicable water quality standards for 

a given pollutant in a specific receiving water (See NPDES Permit Writers Manual, EPA833-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).205

Florida has adopted a regulation authorizing compliance schedules. That 

regulation, Subsection 62-620.620(6), F.A.C., is not affected by this proposed 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 federally-promulgated numeric criteria.

VI. Economic Analysis

 205 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.”
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State implementation of the proposed rule may result in new or revised National 

Pollutant Discharge Elimination System (NPDES) permit conditions for point source 

dischargers, and requirements for nitrogen and phosphorus pollution treatment controls 

on other sources (e.g., agriculture, urban runoff, and septic systems) through the 

development of 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 the proposed rule, and the 

potential State of Florida actions that may be necessary to assure attainment of applicable 

State water quality designated uses. EPA’s analysis is fully described in the document 

entitled Economic Analysis of Proposed Water Quality Standards for the State of 

Florida’s Estuaries, Coastal Waters, and South Florida Inland Flowing Waters, which 

can be found in the docket and record for this proposed rule.

An economic analysis of a proposed regulation compares a likely scenario absent 

the proposed regulation (the baseline) to a likely scenario with the proposed regulation. 

The differences between these two scenarios represent the potential incremental impacts 

of the proposed rule. EPA is promulgating numeric nutrient criteria to address 

deficiencies in the State of Florida’s current narrative nutrient criteria, and the 

incremental impacts of this proposed rule are those associated with the difference 

between EPA’s numeric nutrient criteria and Florida’s narrative criteria. The baseline 

incorporates requirements associated with existing water quality, impaired waters, and 

TMDLs that exist at the time of the analysis. The baseline for this analysis also includes 

EPA’s previously promulgated numeric nutrient criteria for Florida’s lakes and flowing 
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waters, and the potential incremental costs and benefits EPA estimated to be associated 

with that rule. The incremental impacts of the proposed rule are the costs and benefits 

associated with additional pollution controls beyond those currently identified as part of 

the baseline. See section 2 of the economic analysis document where EPA fully describes 

the baseline. 

This analysis is principally designed to gain an understanding of the potential 

costs and benefits associated with implementation of the proposed numeric criteria, 

including DPVs, for estuaries, coastal waters, and south Florida inland flowing waters 

above and beyond the costs associated with State implementation of its current narrative 

nutrient criteria. For waters that the State of Florida has already identified as impaired, 

EPA expects that the effect of this proposed 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 the 

nutrient loadings necessary to meet the numeric criteria that support current State 

designated uses. The further effect of this proposed rule will likely be the assessment and 

identification of additional waters that are impaired and not meeting the designated use 

set forth at Section V.A, 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 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 a part of the baseline). 
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Using this interpretation of the baseline, EPA estimates that the potential 

incremental costs associated with the proposed rule as ranging between $164 million and 

$202 million per year (2010 dollars). 

To develop these estimates, EPA first assessed State control requirements 

associated with existing water quality, impaired waters, and total maximum daily loads, 

as well as regulations specific to estuaries, coastal waters and south Florida inland 

flowing waters (the baseline). EPA then identified the costs and benefits associated with 

additional pollution controls to meet EPA’s proposed numeric criteria, beyond pollution 

controls currently in place or required. To estimate incremental costs to municipal and 

industrial dischargers, EPA gathered publicly available facility information and data on 

potential control technologies, and used Florida Department of Environmental Protection 

(FDEP) point source implementation procedures to project the additional treatment that 

the State may require as a result of the proposed 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 the proposed rule, and 

using FDEP and Florida Department of Agricultural and Consumer Services (FDACS) 

non-point source control procedures, estimated costs to implement agricultural best 

management practices (BMPs) the State may require in order to attain the proposed 

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 water identified 

as impaired under this rule. Finally, EPA qualitatively and quantitatively described and 
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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 result of this analysis represent EPA’s estimates of costs and benefits of the 

State of Florida’s likely actions to implement this proposed rule. 

A. Incrementally Impaired Waters

Compared to current conditions, potentially incrementally impaired waters 

represent waters that exceed EPA’s proposed criteria for which FDEP has not already 

developed a TMDL or listed as impaired for nutrients and DO. To estimate incremental 

costs associated with State control requirements that may be necessary to assure 

attainment of criteria, EPA first removed 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 

estuarine segments that may be identified as incrementally impaired using the criteria of 

this proposed rule. EPA then identified waterbodies (WBIDs206) that surround those 

incrementally impaired segments, and then identified the watersheds that drain to those 

incrementally impaired WBIDs. For coastal criteria set by satellite imagery, EPA 

identified Florida WBIDs that may be identified as incrementally impaired using the 

criteria of this proposal, and then identified the watersheds that drain to those 

incrementally impaired WBIDs. EPA analyzed FDEP’s database of ambient water quality 

 206 WBID is a waterbody identification of which Florida assigns a number, in order to delineate the 

boundaries of Florida’s waters.
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monitoring data and compared monitoring data for each segment with EPA’s proposed 

criteria for TN and TP in estuaries, and south Florida inland flowing waters to identify 

incrementally impaired waters. EPA also analyzed chlorophyll-a data for coastal waters 

by their WBID. EPA compiled the most recent five years of monitoring data, calculated 

the annual geometric mean for each segment or WBID identified by either EPA segment 

boundaries or WBID boundaries, and identified waters as incrementally impaired if they 

exceeded the applicable criteria in this proposed rule as shown in Table VI(A).

Table VI(A): Summary of Incrementally Impairments WBIDs

Category Number of Coastal and Estuarine WBIDs

Total in State 1,143

Total in Analysis1 952

Nutrient Data in IWR Run 442 513

Sufficient Data Available3 410

Exceeding Criteria (incrementally 

impaired)4,5 230

IWR = Impaired Waters Rule

TMDL = total maximum daily load

1. Excluding waters for which FDEP has already developed a TMDL or listed as impaired for 

nutrients and DO

2. Data within last 5 years meeting data quality requirements.

3. Sufficient to calculate annual geometric means; based on at least 4 samples with at least one 

sample from May to September and one sample from October to April in a given year.

4. Based on annual geometric mean exceeding the applicable criterion more than once in a three 

year period

5. Eight coastal WBIDs meet the applicable coastal nutrient criteria but do not meet estuarine 

criteria for the segments to which they are mapped. EPA analyzed these WBIDs among the 

potential incremental impairments.

For downstream protection values (DPVs), EPA conducted a sensitivity analysis for the 

option of meeting numeric nutrient criteria of associated segments/WBIDs at the pour 

point. See Appendix D of the economic analysis for further details.

B. Point Source Costs

Point sources of wastewater must have a National Pollution Discharge 

Elimination System (NPDES) permit to discharge into surface waters. EPA identified 
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point sources potentially discharging nitrogen and phosphorus to estuaries, coastal 

waters, and south Florida inland flowing waters by evaluating the Integrated Compliance 

Information System-National Pollutant Discharge Elimination System (ICIS-NPDES) 

database. EPA identified all industry codes associated with any permitted discharger with 

an existing effluent limit or monitoring requirement for nitrogen or phosphorus. This 

analysis identified 158 point sources as having the potential to discharge nitrogen and/or 

phosphorus. Table VI(B) summarizes the number of point sources with the potential to 

discharge nitrogen and/or phosphorus.

Table VI(B). NPDES-Permitted Wastewater Dischargers Potentially Affected by Proposed Rule

Discharger Category Major Dischargers a Minor Dischargers b Total

Municipal Wastewater 69 38 107

Industrial Wastewater 27 24 51

Total 96 62 158 a Facilities discharging greater than one million gallons per day or 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.207 EPA considered wastewater treatment to these 

concentrations to be the target levels for the purpose of this analysis. 

The NPDES permitting authority determines the need for water quality based 

effluent limits for point sources on the basis of determining their reasonable potential to 

 207 U.S. EPA, 2008, “Municipal Nutrient Removal Technologies Reference Document. Volume 1 –

Technical Report,” EPA 832-R-08-006.
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exceed water quality criteria. To most accurately estimate the potential incremental costs 

for WWTPs, the likelihood that WWTPs discharging to Florida estuaries, coastal waters, 

and south Florida inland flowing waters have reasonable potential to exceed the numeric 

criteria in this proposed rule should be evaluated. However, the site-specific data and 

information required to precisely determine reasonable potential for each facility was not 

available. In the absence of this information two scenarios presented themselves: assume 

all WWTPs have reasonable potential or all WWTPs do not have reasonable potential. 

EPA chose to make the former 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 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.208 Such treatment has not been required for 

WWTPs by the State of Florida in the past, including for those WWTPs under TMDLs 

with nutrient targets comparable to the criteria in this proposed rule. EPA believes that 

should state-of-the-art BNR technology, together with other readily available and 

effective physical and chemical treatment, fall short of 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 

 208 Treatment using reverse osmosis also requires substantial amounts of energy and creates disposal issues 

as a result of the large volume of concentrate generated.
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standards such as reuse, non-point source reductions, site-specific alternative criteria, 

variances, and designated use modifications.

To estimate compliance costs for WWTPs, EPA identified current WWTP 

treatment capabilities using FDEP’s Wastewater Facility Regulation (WAFR) database, 

and 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 the proposed rule because those costs would be incurred absent the rule 

(under the baseline). However, sufficient location information was not available to ensure 

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. Table VI(B)(1)summarizes EPA’s best estimate of the 

number of potentially affected municipal WWTPs that may require additional treatment 

for nitrogen and/or phosphorus to meet the numeric criteria supporting State designated 

uses.

Table VI(B)(1). Summary of Potential for Additional Nutrient Controls for Municipal 

Wastewater Treatment Plants a

Discharge 

Type

Number of Dischargers

Additional 

Reduction in 

TN and TP a

Additional 

Reduction in 

TN Only b

Additional 

Reduction in 

TP Only c

No incremental 

controls needed

d

Total
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Major 9 0 31 29 69

Minor 24 2 1 11 38

Total 33 2 32 40 107

Source: Based on treatment train descriptions in FDEP (2009c) and permits, WLAs in TMDLs and 

existing regulations, assuming dischargers would have to install advanced BNR for compliance under 

the rule.

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.

c. Includes dischargers with Modified Ludzack-Ettinge (MLE), four-stage Bardenpho, and BNR 

specified to achieve less than 3 mg/L, those with WLA under a TMDL for TN only, or those covered 

under the Grizzle-Figg Act.

d. Includes dischargers with anaerobic-anoxic oxidation (A2

/O), modified Bardenpho, modified 

University of Cape Town (UCT), oxidation ditches, or other BNR coupled with chemical precipitation, 

those with WLAs under a TMDL for both TN and TP, those discharging to waters on the 303(d) list for 

nutrients or DO, and ocean dischargers.

An EPA study provides unit cost estimates for BNR for various TN and TP 

performance levels (USEPA 2008a). 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. Multiplying these unit costs by facility flow reported in EPA’s PCS database, 

EPA estimated that total costs could be approximately $94.2 million per year (2010 

dollars).209

EPA also conducted a sensitivity analysis to address the potential for future 

TMDLs for waters currently on the 303(d) list to only develop WLAs for TN or TP (and 

not both pollutants), such that incremental costs could be required under the proposed 

rule to control the other pollutant. The results of this analysis suggest a range of 

additional costs from $0 million (no additional controls) to $23 million (base case plus 

 209 Estimated capital costs annualized at 7% over 20 years, plus estimated annual O&M.
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TP controls for 9 additional dischargers) annually. This resulted in an estimated total cost 

of approximately $94.2 million to $117.5 million per year.

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 identified 51 industrial dischargers potentially affected by the proposed 

rule (Table VI(B)). Of those, 4 are subject to an existing TMDL for nitrogen and/or 

phosphorus, and 6 discharge to waters currently listed as impaired. 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 

proposed rule because those costs would be incurred absent the rule (under the baseline). 

To estimate potential costs to the remaining 41 potentially affected industrial 

facilities, EPA 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 proposed criteria in this proposed 

rule. For those facilities with reasonable potential, EPA further analyzed their effluent 

data and estimated potential revised water quality based effluent limits (WQBELs) 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 designated uses and the costs of those 

controls. EPA then calculated the flow-based cost of compliance for the facilities in each 

industrial category (see economic analysis support document for more information). 
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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.210 EPA believes that should state-of-the-art BNR 

technology, together with other readily available and effective physical and chemical 

treatment, fall short of 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, non-point source 

reductions, site-specific alternative criteria, variances, and designated use modifications.

Using this method, EPA estimated that the potential costs for industrial 

dischargers could be approximately $7.6 million annually (2010 dollars).

Table VI(A)(2): Potential Incremental Costs for Industrial Dischargersa

Industrial Category Total Number of 

Facilities

Total Annual Costs 

(million 2010$/yr)

Chemicals and Allied 

Products 3 $0.3

Electric Services 12 $0 

Food 3 $0.2

Mining 2 $0.04

Other 18 $0

Pulp and Paper 3 $7.1

Total 41 $7.6

mgd = million gallons per day

a May not add due to rounding

 210 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.
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C. Non-point Source Costs

To estimate the potential incremental costs associated with controlling nitrogen 

and phosphorus pollution from non-point sources, EPA identified land areas near 

incrementally impaired waters using GIS analysis. EPA identified all the 10-digit 

hydrologic units (HUCs) in Florida that drain to an incrementally impaired WBID 

(WBIDs are GIS polygons for water assessment), and excluded those HUCs that are 

considered baseline or already costed for in the inland rule. With the remaining HUCs 

identified by their drainage to an incrementally impaired WBID for estuarine, coastal and 

south Florida inland flowing waters, EPA then identified land uses using GIS analysis of 

data obtained from the State of Florida. 

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 56,000 – 87,000 acres (or 8.4%) 

of the land near incrementally impaired waters. EPA’s analysis also indicates that urban 

runoff is already regulated on a portion of this land under EPA’s stormwater program 

requiring municipal separate 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 fewer 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.
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In addition to EPA’s stormwater 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 stormwater rule (Chapter 403 of 

Florida statues) requires stormwater 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 stormwater 

pollutant load reduction goals. In addition, the “Water Resource Implementation Rule” 

(Chapter 62-40, F.A.C.) establishes that stormwater 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 water quality standards (95% 

reduction for outstanding natural resource waters). The rule also states that the pollutant 

loadings from older stormwater 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 earlier, this proposed rule may indirectly result in changes to MS4 NPDES 

permit requirements for urban runoff so that Florida waters meet the proposed criteria. 

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 and phosphorus pollution contained in urban runoff at each 

particular location. Because stormwater programs are usually implemented using an 

iterative approach – with the installation of controls followed by monitoring and re-
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evaluation – estimating the complete set of pollution controls required to meet a 

particular water quality target would require detailed 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 

stormwater controls. FDEP has previously assumed that all urban land developed after 

adoption of Florida's 1982 stormwater rule would be in compliance with this proposed 

rule.211 Using this same assumption, EPA used GIS analysis of land use data obtained 

from the State of Florida212 to identify the amount of remaining urban land located near 

incrementally impaired waters. For Phase I MS4s, EPA used a range of acres with 31,200 

acres as the upper bound and zero acres as the lower bound because Phase I MS4 urban 

areas already must implement controls to the “maximum extent practicable.” As such, 

these municipalities may not need to achieve additional reductions if existing 

requirements are already fully implemented. Using this procedure, EPA estimated that 

55,900 - 87,100 acres may require additional storm water controls.

The cost of stormwater pollution controls can vary widely. FDEP has assessed the 

cost of completed stormwater projects throughout the State in terms of dollars per acre 

treated.213 Capital costs range from $62 to $60,300 per acre treated, with a median cost of 

$6,800 per acre. EPA multiplied the median capital cost per acre by the number of acres 

 211 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.

212 Florida Geological Data Library, 2009. 213 Florida Department of Environmental Protection, 2010, appendix 3.
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potentially requiring controls to estimate the potential incremental stormwater control 

costs associated with the proposed rule. EPA also used FDEP's estimate of operating and 

maintenance (O&M) costs (5% of capital costs), and annualized capital costs using 

FDEP's discount rate of 7% over 20 years. This analysis indicates that urban runoff 

control costs could range from approximately $55.2 to $86.0 million. Table VI(C)(1) 

summarizes these estimates. 

Table VI(C)(1). Potential Incremental Urban Storm Water Cost Scenarios e

Land Type Acres 

Needing 

Controlsa

Capital Cost 

(millions 

2010$)b

O&M Cost

(millions 

2010$)c

Annual Cost

(millions 

2010$)d

MS4 Phase I 0 - 31,000 $0 - $213.3 $0 - $10.7 $0 - $30.8

MS4 Phase II 35,000 $235.9 $11.8 $34.1

Non-MS4 21,000 $146.5 $7.3 $21.2

Total 56,000 -

87,000

$382.4 -

$595.7

$19.1 -

$29.8 $55.2 - $86.0

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 potentially needing controls multiplied by median per-acre 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.

e May not add due to rounding

2. Agricultural Costs 

EPA’s GIS analysis of land use indicates that agriculture accounts for about 

16,600 to 16,619 acres (or 1.3%) of the land near incrementally impaired waters. 

Agricultural runoff can be a source of nitrogen and phosphorus to estuaries, coastal 

waters and south Florida inland flowing waters through the application of fertilizer to 

crops and pastures and from animal wastes. For waters impaired by nitrogen and 

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 the proposed rule may result in 
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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. 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. 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 BMP program,” is a more expensive program designed to supplement 

the “Owner Implemented BMP program” and “Typical BMP program” if additional 

reductions are necessary.

The BMPs in the “Owner Implemented BMP Program” and “Typical BMP 

Program” are similar to the BMPs verified as effective by FDEP and adopted by FDACS. 

EPA has found no indication that the “Alternative BMP Program,” which includes storm 

water chemical treatment, has been required in 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 

combination of the “Owner Implemented BMP Program” and “Typical BMP Program.” 
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Table VI(C)(2) summarizes the potential incremental costs of BMPs on 

agricultural lands in the watersheds of incrementally impaired estuaries, coastal waters 

and southern inland flowing waters for each agricultural category. This analysis indicates 

that incremental agricultural costs resulting from the proposed numeric nutrient criteria 

may be estimated at $0.3 million.

Table VI(C)(2). Potential Incremental Agricultural BMP Costs 

Agricultural 

Category

Area 

Potentially 

Needing 

Controls 

(acres)a

“Owner 

Implemented BMP 

Program” plus 

”Typical BMP 

Program” Unit Costs 

(2010$/ac/yr)e

Total “Owner 

Implemented BMP 

Program” and 

”Typical BMP 

Program” Costs 

(2010$/yr)

Animal Feeding 19 $18.56 $400

Citrus 26 $156.80 $4,000

Cow Calf Production 

(Improved Pastures) 7,449 $15.84 $118,000

Cow Calf Production 

(Unimproved 

Pastures)

1,511 $4.22 $6,400

Cow Calf Production 

(Rangeland and 

Wooded)

2,001 $4.22 $8,500

Row Crop 253 $70.40 $17,800

Cropland and 

Pastureland 

(general)b

38 $27.26 $1,000

Sod/Turf Grass 0 $35.20 $0

Ornamental Nursery 256 $70.00 $18,000

Horse Farms 61 $15.84 $1,000

Field Crop (Hayland) 

Production 4,648 $18.56 $86,300

Other Areas c 358 $18.56 $6,600

Total d 16,619 -- $267,800 a Based on GIS analysis of land use data and FDACS BMP program NOI GIS data layer. 

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.
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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 proposed rule. Several 

nutrient-related TMDLs in Florida identify septic systems as a significant source of 

nitrogen and phosphorus pollution. Although properly operated and maintained systems 

can provide treatment equivalent to secondary wastewater treatment,214

even properly 

functioning septic systems can be expected to contribute to nitrogen and phosphorus 

pollution at some locations.215 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 Florida, EPA assumed that the most likely 

strategy to reduce nutrient loads from septic systems would be to upgrade existing 

conventional septic systems to advanced nutrient removal systems.

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 at least 75 feet from surface waters (F.A.C. 

 214 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. 215 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
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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 waters 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 WBID in 

watersheds associated with incrementally impaired estuaries, coastal waters or south 

Florida inland flowing waters may be identified for upgrade from conventional to 

advanced nutrient removal systems.

EPA identified the number of septic systems within 500 feet of waters in the 

watersheds associated with incrementally impaired estuaries, coastal waters, and South 

Florida inland flowing waters using GIS analysis on data obtained from the Florida 

Department of Health 216 that provides the location of active septic systems in the State. 

This analysis yielded 7,663 active septic systems that may be affected by the proposed 

rule.

EPA evaluated the cost of upgrading existing septic systems to advanced nutrient 

removal systems. Upgrade capital 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. This study 

 216 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.
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estimated the incremental O&M costs for an advanced system to be $650 per year.217

Thus, based on annual O&M costs of $650 and annualizing capital costs at 7% over 20 

years, total 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 in incrementally impaired 

watersheds could range from $5.9 to $9.5 million.

D. Governmental Costs

The proposed rule may result in the identification of incrementally impaired 

waters that would require the development of additional TMDLs. As the principal State 

regulatory agency implementing water quality standard, FDEP may incur costs associated 

with developing additional TMDLs. As described earlier, EPA’s analysis identified 230 

incrementally impaired waters (WBIDs). 

Because current TMDLs for estuaries and coastal waters in Florida include an 

average of approximately four WBIDs each, EPA estimates that the State of Florida may 

need to develop and adopt approximately 58 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 $28,000.218,219 The low end of the range reflects 

the typical cost associated with TMDLs that are the easiest to develop and/or have the 

 217 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).

218 U.S. EPA, 2001, “The National Costs of the Total Maximum Daily Load Program (Draft Report),” 

(EPA-841-D-01-003).

219 EPA did not adjust these estimates to account for potential reductions in resources required to develop 

TMDLs given that scientifically based numeric targets were developed as part of this proposed rule.
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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. 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 

adjusted to 2010 dollars). For 58 TMDLs, total costs for incremental TMDL development 

could be $2.7 million.

FDEP currently operates its TMDL schedule on a five-phase cycle that rotates 

through Florida’s 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. Assuming all the incremental impairments are high 

priority and FDEP develops the new TMDLs over a 9-year period, annual costs could be 

$0.3 million.

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 maintained by the State 

of Florida. Because Florida is currently monitoring TN, TP, and chlorophyll a
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concentrations in many waters, EPA assumed that the rule is unlikely to have a 

significant impact on costs related to water quality monitoring activities.

E. Summary of Costs

Table VI(E) summarizes EPA's estimates of potential incremental costs associated 

with additional State requirements to meet the numeric criteria supporting 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(E). Summary of Potential Annual Costs (millions of 2010 dollars per year)

Source Sector Potential Annual Costs

Municipal Waste Water Treatment Plants $94.2 - $117.5

Industrial Dischargers $7.6

Urban Storm Water $55.2 - $86.0

Agriculture $0.3 

Septic Systems $5.9 - $9.5

Government/Program Implementation $0.3

Total $163.5 – $221.2

F. Benefits

Since elevated concentrations of nutrients in surface waters can result in adverse 

ecological effects and negative economic impacts, EPA expects the proposed numeric 

nutrient criteria to result in significant ecological and economic benefits to Florida. For 

example, excess nutrients in water can cause eutrophication, which can lead to harmful 

(sometimes toxic) algal blooms, loss of rooted plants, and decreased dissolved oxygen. In 

turn, these results can lead to adverse impacts on aquatic life, fishing, swimming, wildlife 

watching, camping, and drinking water. Excess nutrients can also cause nuisance surface 
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scum, reduced food for herbivorous wildlife, fish kills, alterations in fish communities, 

and unsightly shorelines that can decrease property values. 

Nutrient impairment is currently a major concern for many bays, estuaries, and coasts 

within the United States, and is particularly severe for many Florida waters. Florida’s 

2008 Integrated Report stated that 94 estuaries encompassing approximately 900 square 

miles of water are impaired for nutrients, with nutrients ranked as the second most 

common source of impairment. These impairments may have a significant impact on the 

value of environmental goods and services provided by the affected waterbodies. For 

example, the losses of submerged aquatic vegetation resulting from eutrophication can 

have profound economic impacts; FDEP has estimated that each acre of seagrass is worth 

over $20,000 to Florida’s economy annually or $44 billion statewide.220 In 2009, Florida 

seagrass communities supported an estimated harvest of $23 million for just six species 

of commercial fish and shellfish.221

In Florida’s environment and economy, the tourism-focused goods and services 

provided by its bays, estuaries, and coastal waters are particularly valuable. The tourism 

industry of Florida’s nearshore counties contributes approximately $12.4 billion (2004 

dollars) to the state’s economy annually.222 Coral reefs are especially important 

contributors to Florida’s tourism sector. Reef-related recreational expenditures on 

activities such as snorkeling, scuba diving, fishing, and glass bottom boating in four 

 220 Carlson, P. and L. Yarbro. 2008. Seagrass Mapping and Monitoring: Big Bend and Beyond. Presented at 

Florida Water Resources Monitoring Council Meeting, St. Petersburg, FL, September 24-25, 2008. 221 Crist, C. 2010. Seagrass Awareness Month. Statement by the Governor of the State of Florida. 222 National Ocean Economics Program (NOEP). 2006. Coastal Economy Data.
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counties in southeastern Florida for a one year period in 2000-2001 totaled $5.4 

billion.223

The proposed rule will help reduce nitrogen and phosphorus concentrations in 

Florida’s estuaries, coastal waters and south Florida inland flowing waters. In turn, this 

reduction will improve ecological function and prevent further degradation that can result 

in substantial economic benefits to Florida citizens. EPA's economic analysis document 

describes in detail many of the potential benefits associated with meeting the numeric 

criteria in the proposed rule for nitrogen and phosphorus, including reduced human health 

risks, ecological benefits and functions, improved recreational opportunities, aesthetic 

enhancements and others. 

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 individual 

willingness to pay (WTP) for the types of uses that are supported by different water 

quality levels. EPA calculated the baseline water quality index value three ways, using 

each of TN, TP and Ch-a as the determinant of baseline water quality. The baseline 

water quality relied on the percentage difference from proposed criteria levels as a 

measure of exceedances, with the baseline index value set as being inversely related to

exceedances. Lacking information to prefer one baseline method over the others, EPA 

used all three descriptions of baseline water quality to calculate a range of benefits. EPA 

estimated potential changes that would result from implementation of this proposed rule 

 223 Johns, G.M., V.R. Leeworthy, F.W. Bell, and M.A. Bonn. 2001. Socioeconomic Study of Reefs in 

Southeast Florida. Final Report by Hazen and Sawyer for Broward County, Palm Beach County, 

Miami-Dade County, Monroe County, Florida Fish and Wildlife Conservation Commission, and 

National Oceanic and Atmospheric Administration. 
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and their value to a distribution of full-time and part-time 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 $83.7 - $100.1 million as shown in 

Table VI(F). Although these monetized benefits estimates do not account for all potential 

economic benefits arising from the proposed rule, they help to partially demonstrate the 

economic importance of restoring and protecting Florida waters from the impacts of 

nitrogen and phosphorus pollution. 

Table VI(F): Potential Annual State Benefits Associated with the Proposed Criteria (Millions of 2010$)

Baseline WQI Based on % of 

TN Exceedance

Baseline WQI Based on % of 

TP Exceedance

Baseline WQI Based on % of 

Ch-a Exceedance

$100.1 $86.8 $83.7

Ch-a = chlorophyll a

TN = total nitrogen

TP = total phosphorus

WQI = water quality index

VII. Statutory and Executive Order Reviews 

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

Regulation and Regulatory Review) 

Under Executive Order 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 Executive Orders 12866 and 13563 

(76 FR 3821, January 21, 2011) and any changes made in response to OMB 

recommendations have been documented in the docket for this action. This proposed rule 

does not establish any requirements directly applicable to regulated entities or other 

sources of nitrogen and phosphorus pollution. Moreover, existing narrative water quality 
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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 

estuaries and coastal waters in Florida and in south Florida inland flowing waters.

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). This action 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-forprofit enterprise that is independently owned and operated and is not dominant in its 

field.
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Under the CWA water quality standards program, states must adopt water 

quality standards for their waters and must submit those water quality standards to EPA 

for review and approval or disapproval; 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 and regulatory requirements. EPA also 

has the authority to promulgate water quality standards in any case where the 

Administrator determines that a new or revised standard is necessary to meet the 

requirements of the CWA. State standards approved by EPA (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 water quality standards.

Thus, under the CWA, EPA’s promulgation of water quality standards

establishes standards that the State of Florida implements through the NPDES permit 

process. The State has discretion in developing discharge limits, as needed to meet the 

standards. This proposed rule 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 (e.g., relating to compliance schedules, 

variances, etc.). 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 
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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 that include a ”Federal mandate” 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. A “Federal mandate,” is any 

provision in federal statute or regulation that would impose an enforceable duty on State, 

local or Tribal governments or the private sector.224 Before promulgating an EPA rule for 

which a written statement is needed under section 202, 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(a) do not apply 

when they are inconsistent with law. Moreover, section 205(b) 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 

 224 A “Federal mandate” does not include conditions of Federal assistance and generally does not include 

duties arising from participation in a voluntary Federal program.
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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 proposed 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. As these water quality criteria are not self-implementing, EPA’s proposed rule 

does not regulate or affect any entity. Because this proposed rule does not regulate or 

affect any entity, it therefore is not subject to the requirements of sections 202 and 205 of 

UMRA.

EPA determined that this proposed rule contains no regulatory requirements 

that might significantly or uniquely affect small governments. Moreover, water quality 

standards, including those promulgated here, apply broadly to dischargers and are not 

uniquely applicable to small governments. Thus, this proposed 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 
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promulgate Federal water quality standards 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 proposed rule would 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 proposed rule would not alter Florida’s 

considerable discretion in implementing these water quality standards. Further, this

proposed rule would not preclude Florida from adopting water quality standards that EPA 

concludes meet the requirements of the CWA, either before or after promulgation of the 

final rule, which would eliminate the need for Federal standards. Thus, Executive Order 

13132 does not apply to this proposed rule.

Although section 6 of Executive Order 13132 does not apply to this action, EPA 

communicated with the State of Florida to discuss the Federal rulemaking process. In the 

spirit of Executive Order 13132, and consistent with EPA policy to promote 

communications between EPA and State and local governments, EPA specifically solicits 

comment on this proposed rule from State and local officials.

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 
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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 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 water quality standards in their 

respective jurisdictions. These tribes are not subject to this proposed rule. However, this 

rule may impact the tribes because the numeric criteria for Florida will apply to waters 

adjacent to the tribal waters.

EPA has contacted the tribes to inform them of the potential future impact this 

proposal could have on tribal waters. A meeting with tribal officials has been requested to 

discuss the draft proposed rule and potential impacts on the tribes. EPA specifically 

solicits additional comment on this proposed rule from tribal officials.

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 believes 

that 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)
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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 proposed 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 
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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 proposed rule does not have disproportionately high 

and adverse human health or environmental effects on minority or low-income 

populations because it would afford a greater level of protection to both human health 

and the environment if these numeric criteria are promulgated for Class I, Class II and 

Class III waters in the State of Florida.

List of Subjects in 40 CFR Part 131

Environmental protection, Water quality standards, Nitrogen and phosphorus pollution,

Nutrients, Florida.

Dated: March 15, 2012.

Lisa P. Jackson,

Administrator.

For the reasons set out in the preamble, EPA proposes to amend 40 CFR Part 131 as 

follows:

PART 131 – WATER QUALITY STANDARDS 

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

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

Subpart D-[Amended]

2. Section 131.43 is amended as follows:
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a. Revise paragraph (b)(5),

b. Add paragraph (b)(14); and

c. Revise paragraph (c)(2)(i).

3. Section 131.45 is added to read as follows:

§ 131.43 Florida.

* * * * *

(b) * * * 

(5) Lake means a slow-moving or standing body of freshwater or marine water 

that occupies an inland basin that is not a stream, spring, or wetland.

* * * * *

(14) Tidal creek means a portion of a stream that is affected by the ebb and flow 

of ocean tides.

(15) Predominantly marine waters means surface waters in which the chloride 

concentration at the surface is greater than or equal to 1,500 mg/L.

(c) * * * 

(2) * * * 

(i) The applicable instream protection value (IPV) criteria for total nitrogen (TN) 

and total phosphorus (TP) for streams and predominantely freshwater tidal creeks within 

each respective nutrient watershed region are shown on Table 2.

* * * * *

§ 131.45 Water Quality Standards for the State of Florida’s Estuaries, Coastal 

Waters, and South Florida Inland Flowing Waters
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(a) Scope. This section promulgates numeric criteria for nitrogen and phosphorus 

pollution for Class I, Class II 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) Coastal water means all marine waters extending to three nautical miles from 

shore that are not classified as estuaries.

(3) Estuary means predominantly marine regions of interaction between rivers 

and nearshore ocean waters, where tidal action and river flow mix fresh and salt water. 

Such areas include bays, mouths of rivers, and lagoons.

(4) Estuaries and coastal waters means surface waters that have been classified as 

Class II (Shellfish Propagation or Harvesting) 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 marine 

waters.

(5) Everglades Agricultural Area (EAA) means those lands described in Florida 

Statute Section 373.4592 (1994) subsection (15).

(6) Everglades Protection Area (EvPA) means Water Conservation Areas 1

(which includes the Arthur R. Marshall Loxahatchee National Wildlife Refuge), 2A, 2B, 

3A, and 3B, and the Everglades National Park.

(7) Inland flowing waters means inland surface waters that have been classified as 

Class I (Potable Water Supplies) or Class III (Recreation, Propagation and Maintenance 
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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.

(8) Predominantly fresh waters means surface waters in which the chloride 

concentration at the surface is less than 1,500 milligrams per liter.

(9) Predominantly marine waters means surface waters in which the chloride 

concentration at the surface is greater than or equal to 1,500 mg/L.

(10) South Florida inland flowing waters means inland flowing waters in the 

South Florida Region.

(11) South Florida marine waters means predominantly marine waters located in 

the South Florida Region.

(12) 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.

(13) 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.

(14) 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.

(15) 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.
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(16) Tidal creek means a portion of a stream that is affected by the ebb and flow 

of ocean tides.

(c) Criteria for Florida waters.

(1) Criteria for estuaries.

The applicable criteria for total nitrogen (TN), total phosphorus (TP), and 

chlorophyll a for estuaries and predominately marine tidal creeks are shown in Table 1.

 

Table 1. EPA’s Numeric Criteria for Florida’s Estuaries (in geographic order Northwest

to Northeast)

Proposed Criteria

Perdido Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Upper Perdido Bay 0101 0.59 0.042 5.2

Big Lagoon 0102 0.26 0.019 4.9

Central Perdido 

Bay 0103 0.47 0.031 5.8

Lower Perdido Bay 0104 0.34 0.023 5.8

Pensacola Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Blackwater Bay 0201 0.55 0.022 3.9

Upper Escambia

Bay 0202 0.43 0.025 3.7

East Bay 0203 0.50 0.021 4.2

Santa Rosa Sound 0204 0.31 0.018 4.1
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Lower Escambia 

Bay 0205 0.42 0.024 3.9

Upper Pensacola 

Bay 0206 0.40 0.021 3.9

Lower Pensacola 

Bay 0207 0.34 0.020 3.6

Santa Rosa Sound 0208 0.33 0.020 4.1

Santa Rosa Sound 0209 0.36 0.020 5.2

Choctawhatchee 

Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Eastern 

Choctawhatchee 

Bay

0301 0.61 0.035 4.1

Central 

Choctawhatchee 

Bay

0302 0.48 0.017 3.9

Western 

Choctawhatchee 

Bay

0303 0.41 0.015 3.5

St. Andrews Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

East Bay 0401 0.31 0.014 4.6

St. Andrews Sound 0402 0.14 0.009 2.3

Eastern St. Andrews 

Bay 0403 0.24 0.021 3.9

Western St. 

Andrews Bay 0404 0.19 0.016 3.1

Southern St. 

Andrews Bay 0405 0.15 0.013 2.6

North Bay 1 0406 0.22 0.012 3.7

North Bay 2 0407 0.22 0.014 3.7

North Bay 3 0408 0.21 0.016 3.4

West Bay 0409 0.23 0.022 3.8

St. Joseph Bay SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)
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St. Joseph Bay 0501 0.43 0.020 3.0

Apalachicola Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

St. George Sound 0601 0.53 0.019 3.6

Apalachicola Bay 0602 0.51 0.019 2.7

East Bay 0603 0.76 0.034 1.7

St. Vincent Sound 0605 0.52 0.016 12

Apalachicola /

Offshore 0606 0.30 0.008 2.3

Alligator Harbor

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Alligator Harbor 0701 0.36 0.011 2.8

Alligator / Offshore 0702 0.33 0.009 3.1

Alligator / Offshore 0703 0.33 0.009 2.9

Ochlockonee Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Ochlockonee-St. 

Marks Offshore 0825 0.79 0.033 2.7

Ochlockonee

Offshore 0829 0.47 0.019 1.9

Ochlockonee Bay 0830 0.66 0.037 1.8

Ochlockonee Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

St. Marks River 

Offshore 0827 0.51 0.022 1.7

St. Marks River 0828 0.55 0.030 1.2

Big Bend/ 

Apalachee Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Econfina Offshore 0824 0.59 0.028 4.6

Econfina 0832 0.55 0.032 4.4

Big Bend/ 

Apalachee Bay SEGMENT SEGMENT ID TN*(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)
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Fenholloway 0822 1.15 0.44 1.9

Fenholloway 

Offshore 0823 0.48 0.034 10.3

Big Bend/ 

Apalachee Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

SteinhatcheeFenholloway 

Offshore 

0821 0.40 0.023 4.1

Big Bend/ 

Apalachee Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Steinhatchee River 0819 0.67 0.077 1.0

Steinhatchee 

Offshore 0820 0.34 0.018 3.5

Big Bend/ 

Apalachee Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Steinhatchee 

Offshore 0818 0.39 0.032 4.8

Suwannee River

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Suwannee Offshore 0817 1.1 0.090 3.7

Springs Coast

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Waccasassa River 

Offshore 0814 0.38 0.019 3.9

Waccasassa River 

Offshore 0815 0.32 0.019 4.1

Springs Coast

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Crystal River 0812 0.35 0.013 1.3

Crystal-Homosassa 

Offshore 0813 0.36 0.013 2.1

Springs Coast SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)
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Weeki Wachee 

River 0808 0.32 0.010 1.6

Weeki Wachee 

Offshore 0809 0.30 0.010 2.1

Springs Coast

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Pithlachascotee 

River 0806 0.50 0.022 2.4

Pithlachascotee 

Offshore 0807 0.32 0.011 2.5

Springs Coast

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Anclote River 0804 0.48 0.037 4.7

Anclote Offshore 0805 0.31 0.011 3.2

Clearwater 

Harbor/ St. 

Joseph Sound

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Clearwater Harbor 0801 0.47 0.029 5.7

St. Joseph Sound 0802 0.46 0.029 5.5

Clearwater HarborSt. Joseph Offshore 0803 0.29 0.008 2.6

Tampa Bay

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Hillsborough Bay 0901 0.49 0.175 7.7

Old Tampa Bay 0902 0.44 0.172 12.9

Upper Tampa Bay 0903 0.44 0.152 7.9

Middle Tampa Bay 0904 0.37 0.116 6.3

Lower Tampa Bay 0905 0.31 0.074 4.9

Manatee River 0906 0.62 0.115 7.4

Boca Ciega 0907 0.30 0.086 5.3

Sarasota Bay SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Sarasota Bay 1001 0.28 0.119 7.7
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Palm Sola Bay 1002 0.34 0.141 7.2

Roberts Bay 1003 0.34 0.131 8.6

Little Sarasota Bay 1004 0.30 0.123 8.3

Blackburn Bay 1005 0.28 0.118 7.0

Dona Bay 1006 0.24 0.115 4.2

Charlotte Harbor

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Upper 

Caloosahatchee 1101 1.11 0.110 9.9

Lower 

Caloosahatchee 1102 0.61 0.083 3.5

Estero Bay 1103 0.65 0.072 2.3

Matlacha Pass 1104 0.57 0.076 1.6

San Carlos Bay 1105 0.57 0.060 2.4

Peace Estuary 1106 0.79 0.303 3.5

Myakka Estuary 1107 0.71 0.176 3.8

Upper Charlotte 

Harbor 1108 0.71 0.177 2.9

Lower Charlotte 

Harbor 1109 0.61 0.105 2.1

Pine Island Sound 1110 0.56 0.062 2.1

Lake Worth 

Lagoon

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

North Lake Worth 

Lagoon 1201 0.55 0.067 4.7

Central Lake 

Worth Lagoon 1202 0.57 0.089 7.6

South Lake Worth 

Lagoon 1203 0.48 0.034 6.8

Loxahatchee

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Lower Loxahatchee 1301 0.64 0.027 2.9

Middle 

Loxahatchee 1302 0.90 0.041 3.8

Upper Loxahatchee 1303 1.2 0.068 2.8

St. Lucie SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)
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Lower St. Lucie 1401 0.58 0.045 5.3

Middle St. Lucie 1402 0.90 0.12 8.4

Upper St. Lucie 1403 1.22 0.197 8.9

Indian River 

Lagoon

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Upper Mosquito 

Lagoon 1501 1.1 0.05 3.6

Lower Mosquito 

Lagoon 1502 1.3 0.06 7.0

Banana River 1503 1.6 0.06 9.9

Upper Indian River 

Lagoon 1504 1.4 0.06 10

Upper Central 

Indian River 

Lagoon 

1505 1.3 0.06 11

Lower Central 

Indian River 

Lagoon

1506 0.8 0.08 8.0

Lower Indian River 

Lagoon 1507 0.8 0.07 5.6

Halifax River

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Upper Halifax 

River 1601 1.1 0.18 8.8

Lower Halifax 

River 1602 0.85 0.2 9.7

Guana, Tolomato, 

Matanzas, 

Pellicer

SEGMENT SEGMENT ID TN*

(mg/L)

TP 

(mg/L)

Chl-a

1

(μg/L)

Pablo Creek 1701

0.6 0.09 6.6

Cabbage Creek 1702

Guana River 1703

Upper Tolomato 

River 1704

Lower Tolomato 

River 1705

Upper Matanzas 

River 1706
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Central Matanzas 

River 1707

Lower Matanzas 

River 1708

Lower St. Johns 

River

SEGMENT SEGMENT ID TN*

(mg/L) TP (mg/L) Chl-a

1

(μg/L)

Lower St. Johns 

River 1801 0.75 0.095 2.5

Trout River 1802 1.09 0.108 3.6

Trout River 1803 1.15 0.074 7.7

Nassau

SEGMENT SEGMENT ID TN*

(mg/L) TP (mg/L) Chl-a

1

(μg/L)

Lower Nassau 1901 0.33 0.113 3.2

Middle Nassau 1902 0.40 0.120 2.4

Upper Nassau 1903 0.75 0.125 3.4

St. Marys River

SEGMENT SEGMENT ID TN*

(mg/L) TP (mg/L) Chl-a

1

(μg/L)

Lower St. Marys 

River 2002 0.27 0.045 3.0

Middle St. Marys 

River 2003 0.44 0.036 2.7

1 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.

* For a given water body, 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.

(2) Criteria for coastal waters.

The applicable criteria for chlorophyll a for coastal waters are shown in Table 2.

Table 2. EPA’s Numeric Criteria for Florida’s Coastal Waters

Coastal Region Coastal 

Segment225 Approximate Location ChlorophyllRS-a1

* (mg/m3)

 225 Please see TSD for location of Coastal Segments
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Coastal Region Coastal 

Segment225 Approximate Location ChlorophyllRS-a1

* (mg/m3)

Panhandle

1 AL border 2.41

2 Pensacola Bay Pass 2.57

3 1.44

4 1.16

5 1.06

6 1.04

7 1.14

8 Choctawhatchee Bay Pass 1.23

9 1.08

10 1.09

11 1.11

12 1.18

13 1.45

14 St. Andrew Bay Pass 1.74

15 St. Joseph Bay Pass 2.75

16 2.39

17 Southeast St. Joseph Bay 3.47

West Florida 

Shelf

18 5.43

19 4.80

20 4.24

21 3.96

22 Tampa Bay Pass 4.45

23 3.37

24 3.25

25 2.95

26 2.79

27 2.98

28 3.24

29 Charlotte Harbor 4.55

30 4.22

31 3.67

32 4.16

33 5.70

34 4.54

35 4.03

36 Fort Myers 4.61

Atlantic Coast

37 Biscayne Bay 0.92

38 0.26

39 0.26

40 0.24

41 0.21

42 0.21

43 0.20

44 0.20

45 0.21

46 0.25

47 0.57

48 St. Lucie Inlet 1.08

49 1.42

50 1.77

51 1.55
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Coastal Region Coastal 

Segment225 Approximate Location ChlorophyllRS-a1

* (mg/m3)

52 1.44

53 1.53

54 1.31

55 1.40

56 1.80

57 Canaveral Bight 2.73

58 2.33

59 2.28

60 2.06

61 1.92

62 1.76

63 1.72

64 2.04

65 1.92

66 1.86

67 1.95

68 2.41

69 2.76

70 2.80

71 3.45

72 Nassau Sound 3.69

73 3.78

74 Georgia border 4.22 1 ChlorophyllRS-a is remotely sensed calculation of chlorophyll a concentrations. 

* For a given water body, the annual geometric mean of the chlorophyll a concentration shall not exceed 

the applicable criterion concentration more than once in a three-year period.

(3) Criteria for south Florida marine waters.

The applicable criteria for total nitrogen (TN), total phosphorus (TP), and 

chlorophyll a for south Florida marine waters are shown in Table 3.

Table 3. EPA’s Numeric Criteria for South Florida Marine Waters

S. Coastal System Segment 

Code Segment Name TN* (mg/L)

TP* 

(mg/L)

Chlorophyll 

a*1 (μg/L)

Biscayne Bay

NNB Northern North Bay 0.33 0.012 1.82

SNB Southern North Bay 0.31 0.010 1.04

NCI North Central Inshore 0.33 0.008 0.47

SCI South Central Inshore 0.53 0.008 0.41

SCM South Central Mid-Bay 0.40 0.008 0.36

SCO South Central Outer-Bay 0.27 0.007 0.28

CS Card Sound 0.38 0.007 0.38

Florida Bay

MBS Manatee-Barnes Sound 0.74 0.010 0.77

ECFB East Central Florida Bay 0.89 0.009 0.69

CFB Central Florida Bay 1.47 0.025 3.17
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SFB South Florida Bay 0.89 0.011 1.35

WFBN West Florida Bay-North 0.45 0.024 2.98

WFBC West Florida Bay-Central 0.63 0.020 2.06

WFBS West Florida Bay-South 0.34 0.012 1.04

NFB North Florida Bay 0.87 0.015 1.09

CL Coastal Lakes 1.61 0.050 10.22

Florida Keys

FKN Florida Keys-North 0.20 0.007 0.28

FKT Florida Keys-Transition 0.21 0.008 0.34

FKS Florida Keys-South 0.23 0.008 0.37

KWOS Key West-Offshore 0.21 0.008 0.39

BKB Back Bay 0.29 0.009 0.39

BKS Back Shelf 0.26 0.012 0.74

MAR Marquesas 0.24 0.009 0.63

DT Dry Tortugas 0.22 0.008 0.43

Whitewater Bay/ 

Ten Thousand 

Islands

WWB Whitewater Bay 1.05 0.029 4.58

PD Ponce de Leon 0.67 0.026 3.06

SRM Shark River Mouth 1.15 0.027 2.49

CTHB Coastal Harney-Broad River 0.85 0.041 5.44

LMB Lostman Bay 0.90 0.027 4.02

IWW Internal Waterways 0.77 0.037 5.02

GI Gulf Islands 0.54 0.040 3.81

BLK Black River 0.47 0.056 4.21

Pine Island/ 

Rookery Bay

MARC Marco Island 0.37 0.048 5.95

NPL Naples Bay 0.38 0.052 5.22

COCO Cocohatchee 0.55 0.059 6.35

Gulf Shelf GS Gulf Shelf 0.40 0.021 2.88 1 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.

* For a given water body, 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.

(4) Criteria for south Florida flowing waters.

The applicable criteria for South Florida flowing waters that flow into 

downstream estuaries include the downstream protection value (DPV) for total nitrogen

(TN), and total phosphorus (TP) derived pursuant to the provisions of §131.45(c)(5).

These criteria are not applicable to waters within the Everglades Protection Area (EvPA) 

or the Everglades Agricultural Area (EAA).

(5) Criteria for protection of downstream estuaries. (i) A downstream protection 

value (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 estuaries is the allowable 
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Page 188 of 191

concentration of total nitrogen (TN) and/or total phosphorus (TP) applied at the point of 

entry into the estuary. The applicable DPV for any stream flowing into a downstream 

estuary shall be determined pursuant to paragraphs (c)(5)(ii), (iii), or (iv) 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 estuary. If the DPV is not attained 

at the point of entry into the estuary, 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 estuary. 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).

(ii) In instances where available data and/or resources provide for use of a 

scientifically defensible and protective estuary-specific application of water quality 

simulation models that protect the estuary’s designated uses and meet all applicable 

criteria for the estuary, the State or EPA may derive the DPV for TN and/or TP from use 

of an estuary-specific application of water quality simulation models. 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 estuary’s 

designated uses and meet all applicable criteria for the estuary.

(iii) When the State or EPA has not derived a DPV for a stream pursuant to 

paragraph (c)(5)(ii) of this section, and where the downstream estuary attains the 

applicable chlorophyll a criterion and the applicable TP and/or TN criteria, then the DPV 
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for TN and/or TP is the associated ambient instream levels of TN and/or TP at the point 

of entry to the estuary. 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)(5)(ii) of this section.

(iv) When the State or EPA has not derived a DPV pursuant to paragraph 

(c)(5)(ii) of this section, and where the downstream estuary 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 estuary as described in §131.45(c)(1).

(v) The State and EPA shall maintain a record of DPVs they derive based on the 

methods described in paragraphs (c)(5)(ii) and (iii) 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)(5)(ii) or (iii) of this section.

(d) Applicability. (1) The criteria in paragraphs (c)(1) through (5) of this section 

apply to all Class I, Class II and Class III waters in Florida, 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
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(iii) The State adopts and EPA approves a water quality standards variance to the 

Class I, Class II, or Class III designated use pursuant to §131.13 that meets the applicable 

provisions of State law and the applicable Federal regulations at §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 

§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 estuary criteria in paragraph (c)(1) or 

(c)(3) of this section. 

(ii) Replicate the process for developing the coastal criteria in paragraph (c)(2) or 

(c)(3) of this section.
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(iii) Replicate the process for developing the flowing water criteria in paragraph 

(c)(4) of this section.

(vi) Conduct a biological, chemical, and physical assessment of water body 

conditions. 

(vii) 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 [INSERT DATE 60 DAYS AFTER 

PUBLICATION IN THE FEDERAL REGISTER].