Economic Analysis of Final Water Quality Standards for Nutrients for Lakes 

and Flowing Waters in Florida

November 2010 

U.S. Environmental Protection Agency 

Office of Water

Office of Science and Technology

1200 Pennsylvania Avenue N.W. 

Washington, D.C. 20460 
November 2010 i 

T able of C ontents

Executive Summary .................................................................................................................................... 1

1. Introduction ................................................................................................................................... 1-1

1.1 Requirement for the Rule ................................................................................................................ 1-1

1.2 Purpose and Scope of the Analysis.................................................................................................. 1-1

1.3 Organization of this Report ............................................................................................................. 1-2

2. Baseline for the Analysis ............................................................................................................... 2-1

2.1 Current Regulatory Framework ....................................................................................................... 2-1

2.1.1 Water Quality Standards ....................................................................................................... 2-1

2.1.2 Restoration of Designated Uses in Impaired Waters ............................................................ 2-3

2.1.3 Existing Regulations for Point Source Dischargers .............................................................. 2-6

2.1.4 Existing Regulations for Urban Areas .................................................................................. 2-6

2.1.5 Existing Requirements for Agriculture ................................................................................. 2-8

2.1.6 Existing Requirements for Forestry .................................................................................... 2-13

2.1.7 Existing Requirements for Septic Systems ......................................................................... 2-14

2.1.8 Existing Requirements for Air Sources ............................................................................... 2-14

2.1.9 Legacy Sources ................................................................................................................... 2-14

2.1.10Summary and Assumptions ................................................................................................ 2-14

2.2 Existing Nutrient Discharges to Freshwater Lakes and Flowing waters ....................................... 2-15

2.2.1 Wastewater Point Sources ................................................................................................... 2-15

2.2.2 Stormwater .......................................................................................................................... 2-17

2.2.3 Agriculture .......................................................................................................................... 2-19

2.2.4 Septic Systems .................................................................................................................... 2-20

2.2.5 Atmospheric Deposition ..................................................................................................... 2-21

2.2.6 Legacy Sources ................................................................................................................... 2-22

2.2.7 Summary and Assumptions ................................................................................................ 2-22

2.3 Current Water Quality ................................................................................................................... 2-22

2.3.1 Category 5 Waters on State 303(d) List .............................................................................. 2-23

2.3.2 Nutrient TMDLs ................................................................................................................. 2-23

2.3.3 Summary and Assumptions ................................................................................................ 2-28

3. Description of the Rule .................................................................................................................. 3-1

3.1 Water Quality Criteria ..................................................................................................................... 3-1

3.2 Potential Implementation ................................................................................................................. 3-4

3.2.1 Impaired Waters and TMDLs ............................................................................................... 3-5

3.2.2 Controls for Point and Nonpoint Sources ............................................................................. 3-5
November 2010 ii

4. Potential Costs for Municipal Wastewater Sources ................................................................... 4-1

4.1 Data ................................................................................................................................................. 4-1

4.2 Method ............................................................................................................................................. 4-1

4.2.1 Reasonable Potential ............................................................................................................. 4-1

4.2.2 Water Quality Based Effluent Limits .................................................................................... 4-2

4.2.3 Potential Compliance Options............................................................................................... 4-2

4.2.4 Potentially Affected Sources ................................................................................................. 4-5

4.2.5 Potential Control Costs ......................................................................................................... 4-6

5. Potential Costs for Industrial Wastewater Sources .................................................................... 5-1

5.1 Data ................................................................................................................................................. 5-1

5.2 Method ............................................................................................................................................. 5-2

5.2.1 Sample Dischargers ............................................................................................................... 5-2

5.2.2 Potential Compliance Options............................................................................................... 5-3

5.2.3 Potential Control Costs ......................................................................................................... 5-3

6. Potential Incrementally Impaired Waters and Watersheds ...................................................... 6-1

6.1 Data ................................................................................................................................................. 6-1

6.2 Method ............................................................................................................................................. 6-2

6.3 Results ............................................................................................................................................. 6-3

6.4 Land Use .......................................................................................................................................... 6-5

7. Potential Costs to Urban Stormwater Sources ........................................................................... 7-1

7.1 Data ................................................................................................................................................. 7-1

7.2 Method ............................................................................................................................................. 7-1

7.2.1 Controls for Lakes and Streams ............................................................................................ 7-1

7.2.2 Controls for Impaired Springs ............................................................................................... 7-4

7.2.3 Potential Costs....................................................................................................................... 7-4

8. Potential Costs to Agricultural Sources ....................................................................................... 8-1

8.1 Data ................................................................................................................................................. 8-1

8.2 Method ............................................................................................................................................. 8-2

8.3 Potential Costs ................................................................................................................................. 8-4

8.3.1 Lakes and Streams ................................................................................................................ 8-4

8.3.2 Springs .................................................................................................................................. 8-5

8.4 Summary of Potential Costs to Agricultural Sources ...................................................................... 8-6

9. Potential Costs for Septic Systems ............................................................................................... 9-1

9.1 Data ................................................................................................................................................. 9-1
November 2010 iii

9.2 Method ............................................................................................................................................. 9-1

9.2.1 Lakes and Streams ................................................................................................................ 9-1

9.2.2 Springs .................................................................................................................................. 9-2

9.3 Potential Costs ................................................................................................................................. 9-2

9.4 Results ............................................................................................................................................. 9-3

10. Governmental Expenditures ....................................................................................................... 10-1

10.1 New TMDLs .................................................................................................................................. 10-1

10.2 Site Specific Alternative Criteria ................................................................................................... 10-2

10.3 Ambient Monitoring ...................................................................................................................... 10-2

11. Summary of Potential Costs ....................................................................................................... 11-1

11.1 Potential Costs Associated with Incremental Impairments ........................................................... 11-1

11.2 Uncertainties of Analysis .............................................................................................................. 11-2

12. Description of Benefits of Reducing Nutrient Loads to Lakes and Flowing Waters in Florida12-1

12.1 Effect of Nutrients on Lakes and Flowing Waters ........................................................................ 12-1

12.1.1Ecological Effects ............................................................................................................... 12-1

12.1.2Primary and Secondary Eutrophication Responses ............................................................. 12-2

12.1.3Mitigating Factors ............................................................................................................... 12-4

12.2 Impacts of Nutrients on Environmental Goods and Services ........................................................ 12-5

12.2.1Impacts of HABs ................................................................................................................. 12-5

12.2.2Impacts of Aquatic Vegetation Loss ................................................................................... 12-6

12.2.3Impacts of Degraded Water Quality ................................................................................... 12-6

12.3 Types of Benefits Associated with Nutrient Reductions ............................................................... 12-6

12.3.1Human Health Improvements ............................................................................................. 12-7

12.3.2Ecological Improvements.................................................................................................... 12-8

12.4 Avoided Habitat Restoration and Treatment Costs ..................................................................... 12-15

13. Potential Incremental Benefits of the Numeric Nutrient Criteria .......................................... 13-1

13.1 Water Quality Index ...................................................................................................................... 13-1

13.1.1Relation between WQI and Suitability for Human Uses .................................................... 13-7

13.1.2Baseline Ambient Water Quality ........................................................................................ 13-7

13.1.3Estimated Changes in Water Quality from Attaining Criteria ............................................ 13-9

13.2 Willingness to Pay for Water Quality Improvements.................................................................. 13-10

13.3 Estimating Total WTP for Water Quality Improvements ............................................................ 13-14

13.4 Uncertainty and Limitations ........................................................................................................ 13-15

14. References .................................................................................................................................... 14-1
November 2010 iv

Appendix A. Potential Incremental Costs Associated with EPA’s Rule Compared to FDEP’s 2009 

Draft Numeric Nutrient Criteria................................................................................................. A-1

Appendix B. Sensitivity Analysis: Potential Impacts without DPVs for Stream Criteria ................ B-1

Appendix C. Municipal WWTP Cost Estimates .................................................................................. C-1

Appendix D. Industrial Sample Discharger Analyses ......................................................................... D-1

Appendix E. Potential Effect of Nutrient Criteria on Response Indicators and Biota ..................... E-1

Appendix F. Quantitative Analysis of Benefits: Potential Value of Improvements in DO............... F-1
November 2010 v 

L is t of E xhibits

Exhibit ES-1: Summary of Dischargers in Florida Potentially Affected by Numeric Nutrient Criteria for 

Lakes and Flowing Waters1

 .................................................................................................................. 2

Exhibit ES-2: Summary of Agricultural Lands Enrolled in FDACS BMP Program .................................... 3

Exhibit ES-3: Numeric Nutrient Criteria for Lakes and Flowing Waters in Florida .................................... 5

Exhibit ES-4: Summary of Identification of Potential Incrementally Impaired Waters ............................... 7

Exhibit ES-5: Estimates of Potential Annual Costs Associated with Numeric Nutrient Criteria (2010 

dollars) ................................................................................................................................................ 11

Exhibit ES-6: Estimated Total Average Annual Benefits for Water Quality Improvement to Freshwater 

Flowing Waters and Lakes in Florida (millions of 2010 dollars per year) ......................................... 13

Exhibit 2-1: FDEP July 2009 Draft Numeric Nutrient Criteria for Lakes and Streams ............................ 2-3

Exhibit 2-2: Summary of Completed Nutrient Basin Management Action Plans ..................................... 2-4

Exhibit 2-3: NPDES Dischargers with Numeric Effluent Limits and Monitoring Requirements for 

Nitrogen and Phosphorus in Florida1 ............................................................................................... 2-16

Exhibit 2-4: Summary of NPDES Dischargers in Florida Potentially Affected by Numeric Nutrient 

Criteria for Lakes and Flowing Waters1

 .......................................................................................... 2-17

Exhibit 2-5: MS4 Stormwater Control Projects in Florida ...................................................................... 2-18

Exhibit 2-6: Summary of Agricultural Lands Enrolled in FDACS BMP Program ................................. 2-19

Exhibit 2-7: Summary of CWA Section 303(d) Listed Impairments for Nutrients in Florida1 ............... 2-23

Exhibit 2-8: Summary of Nutrient-Related TMDLs for Lakes and Flowing Waters in Florida .............. 2-23

Exhibit 2-9: Map of Baseline Impairments in Florida ............................................................................. 2-27

Exhibit 2-10: Summary of Land Use for Baseline Impairments .............................................................. 2-28

Exhibit 3-1: Summary of Florida Waters ................................................................................................... 3-1

Exhibit 3-2: Numeric Nutrient Criteria for Lakes and Flowing Waters in Florida .................................... 3-1

Exhibit 3-3: Lake Types in Florida ............................................................................................................ 3-3

Exhibit 3-4: Numeric Nutrient Criteria Regions for Streams in Florida .................................................... 3-4

Exhibit 4-1: Summary of Applicable Criteria for Municipal WWTP Discharging to Freshwater Lakes and 

Streams............................................................................................................................................... 4-1

Exhibit 4-2: Comparison of Common BNR Configurations ...................................................................... 4-3

Exhibit 4-3: Potential Treatment Required for Municipal Wastewater Treatment Plants1 ........................ 4-6

Exhibit 4-4: BNR Capital and O&M Unit Costs (2010 dollars)1 ............................................................... 4-7

Exhibit 4-5: Treatment Level and Costs for Municipal Wastewater Treatment Plants ............................. 4-8

Exhibit 5-1: Summary of Potentially Affected Industrial Dischargers ...................................................... 5-1

Exhibit 5-2: Summary of Industrial Sample by Category .......................................................................... 5-2
November 2010 vi

Exhibit 5-3: Estimated Statewide Annual Industrial Control Costs ........................................................... 5-4

Exhibit 6-1: Potential Incrementally Impaired Waters .............................................................................. 6-3

Exhibit 6-2: Map of Potential Incrementally Impaired Waters Affected by the Rule ............................... 6-4

Exhibit 6-3: Summary of Land Use for Potential Incrementally Impaired Watersheds ............................ 6-5

Exhibit 7-1: Urban Land Area in Incrementally Impaired Watersheds ..................................................... 7-1

Exhibit 7-2: Urban Land in Incrementally Impaired Watersheds Potentially Needing Controls .............. 7-4

Exhibit 7-3: Estimated Incremental Urban Stormwater Cost Scenarios .................................................... 7-4

Exhibit 8-1: Agricultural Land Use in Incrementally Impaired Watersheds ............................................. 8-1

Exhibit 8-2: Example Agricultural BMP Program Elements for the Caloosahatchee River and St. Lucie 

River Watersheds ............................................................................................................................... 8-2

Exhibit 8-3: Potential Agricultural Control Costs Associated with Incrementally Impaired Lakes and 

Streams............................................................................................................................................... 8-4

Exhibit 8-4: Potential Agricultural Control Costs Associated with Incrementally Impaired Springs ....... 8-6

Exhibit 8-5: Potential Annual Incremental Control Costs for Agricultural Sources .................................. 8-6

Exhibit 11-1: Summary of Potential Annual Costs Associated with Numeric Nutrient Criteria (2010 

dollars) ............................................................................................................................................. 11-1

Exhibit 11-2: Uncertainties of the Analysis ............................................................................................. 11-2

Exhibit 12-1: Eutrophication Impacts and Responses for Lakes and Flowing Waters ............................ 12-2

Exhibit 12-2: Types of Benefits Associated with Environmental Policies .............................................. 12-7

Exhibit 12-3: Mean Implicit Price of a 17% Change in Water Quality ................................................. 12-12

Exhibit 12-4: Implicit Price Gradients ................................................................................................... 12-13

Exhibit 12-5: Implicit Price of Lake Water Quality in Other Studies .................................................... 12-13

Exhibit 12-6: Habitat Restoration and Treatment Costs For Upper Ocklawaha River Basin, FL ......... 12-16

Exhibit 12-7: Planning Level Estimates for Sweetwater Branch Sheetflow Restoration Project .......... 12-19

Exhibit 12-8: Examples of Costs for Regional Stormwater Treatment Facilities in Florida ................. 12-19

Exhibit 12-9: Dredging Costs for Florida Lakes .................................................................................... 12-20

Exhibit 13-1: Distribution of TN and TP Concentrations in Florida Lakes and Flowing waters and 

Corresponding Subindex (SI) Value. ............................................................................................... 13-3

Exhibit 13-2: Freshwater Water Quality Subindices1 .............................................................................. 13-4

Exhibit 13-3: TSS, TN, and TP Subindex Curve Parameters .................................................................. 13-5

Exhibit 13-4: Subindex Curves for the 6 WQI Parameters. ..................................................................... 13-6

Exhibit 13-5: Original and Revised Weights for Freshwater WQI Parameters ....................................... 13-7

Exhibit 13-6: Water Quality Classifications ............................................................................................ 13-7
November 2010 vii

Exhibit 13-7: Estimated Percentage of Freshwater Flowing Water and Spring Miles in Florida by WQI 

Classifications: Baseline Scenario ................................................................................................... 13-8

Exhibit 13-8: Estimated Percentage of Lake Area in Florida by WQI Classification: Baseline Scenario . 13-

9

Exhibit 13-9: Potential Water Quality Improvements in Flowing waters and Springs .......................... 13-10

Exhibit 13-10: Potential Water Quality Improvements in Lakes ........................................................... 13-10

Exhibit 13-11: Independent Variable Assignments ............................................................................... 13-11

Exhibit 13-12: Estimated Average Annual Household WTP for Water Quality Improvement in Florida 

(2010$) ........................................................................................................................................... 13-14

Exhibit 13-13: Potential Annual Benefits for Water Quality Improvement to Freshwater Flowing Waters 

and Lakes in Florida (Millions of 2010$ per year) ........................................................................ 13-15

Exhibit A-1. Potential Incrementally Impaired Waters under FDEP July 2009 Draft Numeric Nutrient 

Criteria .............................................................................................................................................. A-1

Exhibit A-2. Summary of Land Use for Potential Incrementally Impaired Watersheds: EPA Rule 

Compared to FDEP July 2009 Draft Numeric Nutrient Criteria1

 ..................................................... A-2

Exhibit A-3: Urban Land in Incrementally Impaired Watersheds based on FDEP’s 2009 Draft Nutrient 

Criteria Potentially Needing Controls ............................................................................................... A-2

Exhibit A-4: Estimated Urban Stormwater Cost Scenarios Associated with FDEP’s July 2009 Draft 

Nutrient Criteria (2010 dollars) ........................................................................................................ A-3

Exhibit A-5: Potential Incremental Urban Stormwater Costs: FDEP July 2009 Draft Criteria Baseline . A-3

Exhibit A-6: Potential Agricultural Control Costs Associated with Incrementally Impaired Lakes and 

Streams based on FDEP’s 2009 Draft Nutrient Criteria ................................................................... A-4

Exhibit A-7: Potential Agricultural Control Costs Associated with Impaired Springs based on FDEP’s 

2009 Draft Nitrate-Nitrite Criterion .................................................................................................. A-5

Exhibit A-8: Potential Annual Control Costs for Agricultural Sources based on FDEP’s July 2009 Draft 

Nutrient Criteria ................................................................................................................................ A-5

Exhibit A-9: Potential Incremental Agriculture Costs: FDEP July 2009 Draft Criteria Baseline ............ A-5

Exhibit A-10: Potential Incremental Costs Associated with Upgrading Septic Systems: FDEP 2009 Draft 

Criteria Baseline ............................................................................................................................... A-6

Exhibit A-11: Potential Incremental Costs Associated with EPA’s Numeric Nutrient Criteria: FDEP 2009 

Draft Criteria Baseline (2010 dollars) ............................................................................................... A-7

Exhibit B-1: Potential Incrementally Impaired Streams with and without Consideration of DPVs ......... B-1

Exhibit B-2: Estimated Incremental Urban Stormwater Costs: No DPVs ................................................ B-2

Exhibit B-3: Potential Incremental Agricultural Control Costs for Lakes and Streams: No DPVs .......... B-3

Exhibit B-4: Potential Agricultural Control Costs Associated with Incrementally Impaired Springs: No 

DPVs ................................................................................................................................................. B-4

Exhibit B-5: Potential Annual Incremental Control Costs for Agricultural Sources: No DPVs .............. B-4
November 2010 viii

Exhibit B-6: Comparison of Potential Annual Costs Associated with Numeric Nutrient Criteria (2010 

dollars) .............................................................................................................................................. B-5

Exhibit C-1: Potential Costs to Municipal WWTPs for Compliance with Numeric Nutrient Criteria ..... C-1

Exhibit D-1. Effluent Data Summary, Mosaic Fertilizer - Hopewell ....................................................... D-2

Exhibit D-2. Effluent Data Summary, Pilgrim’s Pride ............................................................................. D-4

Exhibit D-3. Effluent Data Summary, Imperial Brands – Lake Alfred .................................................... D-6

Exhibit D-4. Effluent Data Summary, Packaging Corporation of America .............................................. D-7

Exhibit D-5. Effluent Data Summary, St. Marks Powder Inc. .................................................................. D-9

Exhibit D-6. Effluent Data Summary, Aramark Uniform and Career Apparel ...................................... D-11

Exhibit D-7. Effluent Data Summary, Tampa Electric – Polk Power Station ........................................ D-13

Exhibit D-8. Effluent Data Summary, Universal Studios Florida........................................................... D-15

Exhibit F-1: Freshwater Water Quality Sub-indices for DO .................................................................... F-4

Exhibit F-2: Summary of Available %DOsat data by Waterbody Type ................................................... F-5

Exhibit F-3: Florida Annual Temperatures ............................................................................................... F-5

Exhibit F-4: Summary of DOsat for Lakes and Flowing Waters ................................................................ F-6

Exhibit F-5: Potential Improvements in Flowing Water and Spring Miles .............................................. F-9

Exhibit F-6: Potential Improvements in Lake Area .................................................................................. F-9

Exhibit F-7: Potential Average Annual Household WTP for Water Quality Improvement in Flowing 

Waters in Florida (2010$) ............................................................................................................... F-10

Exhibit F-8: Potential Average Annual Household WTP for Water Quality Improvement in Lakes in 

Florida (2010$) ............................................................................................................................... F-10

Exhibit F-9: Potential Total Benefits for Water Quality Improvement to Freshwater Flowing waters in 

Florida (Millions of 2010$) ............................................................................................................ F-11

Exhibit F-10: Estimated Total Benefits for Water Quality Improvement to Freshwater Lakes in Florida 

(Millions of 2010$) ......................................................................................................................... F-11
November 2010 ix

Ac ronyms and Abbreviations

A2

/O Anaerobic-anoxic oxidation

ANMP Agricultural nutrient management plan

BMAP Basin Management Action Plan

BMP Best management practice

BNR Biological nutrient removal

BOD Biochemical oxygen demand 

C&D Construction and development

CAFO Confined animal feeding operation

cfs Cubic feet per second 

CH Chlorophyll a 

COI Cost of illness

CREP Conservation Reserve Enhancement Program 

CRP Conservation Reserve Program

CSP Conservation Stewardship Program 

CTA Conservation Technical Assistance 

CWA Clean Water Act

DACS Department of Agriculture and Consumer Services 

DOH Department of Health

DPV Downstream protection value 

DO Dissolved Oxygen

DOF Department of Forestry

EAA Everglades Agriculture Area

EPA U.S. Environmental Protection Agency 

EQIP Environmental Quality Incentive Program 

F.A.C. Florida Administrative Code

FC Fecal coliform

FDACS Florida Department of Agriculture and Consumer Services 

FDEP Florida Department of Environmental Protection

FDOF Florida Division of Forestry

FDOH Florida Department of Health 

F.S. Florida Statutes

FWRA Florida Watershed Restoration Act 

GAC Granulated activated carbon

GIS Geographic information systems

GLCI Grazing Land Conservation Initiative 

HABs Harmful algal blooms

HUC Hydrologic unit code 

IPM Integrated pest management

IWR Impaired Waters Rule

LSJR Lower St. Johns River

MEP Maximum extent practicable

MIB 2-methylisborneol

MLE Modified Ludzack-Ettinger

MS4 Municipal separate storm sewer system
November 2010 x 

NO2 Nitrate

NO3 Nitrite

NOI Notice of intent

NRCS Natural Resource Conservation Service

NPDES National Pollutant Discharge Elimination System

NWIS National Water Information System

O&M Operation and maintenance 

OCBWG Orange Creek Basin Working Group

OIG Office of Inspector General

OSTDS Onsite sewage treatment and disposal system

PAC Powered activated carbon

PCS Permit compliance system

Pt-Co Platinum cobalt units 

RA Reasonable assurance

RBC Rotating biological contactor 

SBR Sequencing batch reactor 

SCR Selective catalytic reduction

SDT Secchi disk transparency

SDM Secchi disk measurement

SFWMD South Florida Water Management District 

SIC Standard industrial classification

SJWMD St. Johns Water Management District

SMP Strategic monitoring plans

SMZ Special Management Zone

SSAC Site specific alternative criteria

SWET Soil and Water Engineering Technology, Inc.

SWIM Surface Water Improvement and Management

SWMP Stormwater management program

TMDL Total maximum daily load

TN Total nitrogen

TP Total phosphorus 

TSD Technical Support Document for Water Quality-Based Toxics Control

TSI Trophic state index

TSS Total suspended solids

UCT University of Cape Town 

USDA United States Department of Agriculture

USGS United States Geological Survey

WAFR Wastewater facility regulation

WBID Waterbody identification

WLA Wasteload allocation

WOD Works of the District

WQBEL Water quality-based effluent limit

WQI Water quality index 

WQL Water quality ladder

WQS Water quality standards

WRF Water reclamation facility
November 2010 xi

WTP Willingness to pay

WWTP Wastewater treatment plant
November 2010 Executive Summary ES-1

Executive Summary

The U.S. Environmental Protection Agency (EPA) is promulgating numeric nutrient criteria applicable to 

freshwater lakes and flowing waters in the state of Florida. EPA’s criteria will supplement the state’s 

existing narrative nutrient criterion. Although this rule does not establish any requirements directly 

applicable to regulated entities or other sources of nutrient pollution, EPA developed this economic 

analysis to provide information on potential costs and benefits that may indirectly be associated with state 

implementation of this rule including potential requirements that may be necessary to assure attainment of 

the criteria. 

ES.1 Background and Purpose

The state of Florida currently uses a narrative criterion to protect waters from nutrient pollution. In 

January of 2009, EPA determined that new or revised WQS for nutrients in the form of numeric nutrient 

criteria are necessary in Florida to meet the requirements of the CWA (U.S. EPA, 2009a). In August of 

2009 EPA entered into a phased Consent Decree with several environmental organizations that 

challenged the Agency for not having promulgated numeric nutrient criteria for the State of Florida. In 

that Consent Decree, EPA committed to issue a final numeric nutrient rule for Florida’s inland waters by 

October 15, 2010 which was subsequently extended to November 14, 2010. This rule will satisfy that 

requirement of the Consent Decree.

EPA’s rule establishes numeric water quality criteria for nitrogen and phosphorus applicable to lakes and 

flowing waters in defined regions of Florida to ensure the attainment of State designated uses. The rule 

does not establish any requirements directly applicable to regulated entities or other sources of nutrient 

pollution to these waters. Nonetheless, state implementation of the criteria may result in new or revised 

National Pollutant Discharge Elimination System (NPDES) permit conditions for point source dischargers 

and nutrient control requirements for other sources (e.g., agriculture, urban runoff, and septic systems). 

Therefore, to provide information on such potential impacts, this report provides estimates of the potential 

costs and benefits that may be indirectly associated with the rule. 

ES.2 Baseline for the Analysis

The baseline for estimating the potential costs and benefits that may be associated with EPA’s rule is the 

conditions and requirements that would exist without EPA’s rule. These conditions include the current 

narrative nutrient criterion and procedures for identifying impaired waters, and the actions that would be 

needed to attain the narrative criterion (including those that have not yet been implemented). There are 

hundreds of lakes and flowing waters in Florida currently listed as impaired under the narrative criterion. 

FDEP has developed total maximum daily loads (TMDLs) for many of these waters, and has developed 

or is developing Basin Management Action Plans (BMAPs) to implement some of those TMDLs. Under 

TMDLs, point sources may receive revised water quality based effluent limits (WQBELs) for total 

nitrogen (TN) and/or total phosphorus (TP). Under BMAPs, nonpoint sources, including agriculture, 

urban stormwater, and septic systems, may be required to implement additional nutrient controls. 

EPA believes that current requirements represent a useful baseline from which to evaluate potential 

actions that may be associated with the criteria in the rule. However, in July 2009 the Florida Department 

of Environmental Protection (FDEP) released draft numeric nutrient criteria for lakes and flowing rivers. 

Although the state of Florida has not adopted those numeric criteria provisions, EPA believes that 
November 2010 Executive Summary ES-2

FDEP’s draft numeric nutrient criteria may also represent a useful baseline from which to evaluate EPA’s 

action. This document presents estimates under both baseline interpretations.

Point Sources

EPA’s permit compliance system (PCS) database indicates that there are 198 municipal wastewater 

dischargers and 245 industrial dischargers with individual permits.1 Some of these permittees discharge to 

estuarine waters, coastal waters, or South Florida canals that are not affected by the lakes and flowing 

waters rule. For example, of the 198 municipal wastewater treatment plants (WWTP), EPA determined 

that only 85 discharge to freshwater lakes and streams. Given the nature of influent wastewater at 

municipal WWTPs, it is likely that all WWTPs have the potential to discharge nutrients. To identify 

industrial dischargers likely to discharge nutrients, EPA identified those dischargers in PCS with either 

numeric effluent limits and/or monitoring requirements for nitrogen and phosphorus. Based on these 

industrial categories, Exhibit ES-1 summarizes the number of NPDES-permitted wastewater dischargers 

in Florida that may be affected by the rule. 

Exhibit ES-1: Summary of Dischargers in Florida Potentially Affected by Numeric 

Nutrient Criteria for Lakes and Flowing Waters1

Discharger Category Major Dischargers Minor Dischargers Total

Municipal Wastewater 43 42 85

Industrial Wastewater2 57 51 108

Total 100 93 193

Source: U.S. EPA (2010a).

Major = generally discharge greater than 1 mgd and have the potential to discharge toxics in toxic amounts

Minor = generally discharge less than 1 mgd and do not discharge toxics in toxic amounts.

SIC = Standard Industrial Classification

TMDL = total maximum daily load

1. Excludes dischargers to oceans, estuaries, bayous, wetlands, and South Florida flowing waters (identified 

based on receiving waterbody name and information contained TMDLs, permits, and laboratory reports). 

2. For majors dischargers includes SIC codes 1475, 1479, 2015, 2611, 2621, 2631, 2821, 2824, 2874, 2879, 

2892, and 4911; for minor dischargers includes SIC codes 1099, 1422, 1475, 2033, 2034, 2037, 2082, 2085, 

2491, 2499, 2611, 2869, 2873, 2874, 3582, 3679, 3699, 3822, 4011, 4226, 4931, 4941, 4952, 4953, 5146, 5169, 

5171, 5541, 7996, 8422, 8733, 9511, and 9999.

Urban Sources

Urban runoff from fertilizers applied to lawns, gardens, and golf courses, decomposition of natural rock 

and soils, air deposition from vehicle exhaust or power plants, detergents used to wash cars on the street, 

and pet waste can account for significant nutrient pollution in watersheds. There are several rules in place 

that regulate these sources. For example, the state’s Urban Turf Fertilizer Rule limits the nutrient content 

of turf fertilizers, which decreases the amount runoff from its application. Also, municipal separate storm 

sewer systems (MS4s) develop and implement management plans that include measures that may reduce 

runoff of nutrients such as public education and pollution prevention/good housekeeping activities. 

FDEP’s 1982 Stormwater Rule also requires that all stormwater from new development and 

 

1 There are also 34,508 dischargers covered under generic or general permits. FDEP regulate these dischargers based on 

categories of wastewater facilities or activities that involve the same or similar types of operations or wastes. EPA did not include 

these dischargers in its analysis.
November 2010 Executive Summary ES-3

redevelopment receive treatment prior to discharge. To date, FDEP has issued 27 Phase I (large and 

medium-sized) MS4 permits and 133 Phase II (small) MS4 permits in Florida.

Agricultural Sources

There are currently about 9.2 million acres of farmland in Florida. These lands may represent significant 

sources of nutrients from fertilizer and waste runoff, and are subject to several federal and state pollution 

control regulations. Confined animal feeding operations (CAFOs) must obtain NPDES permits. Also, the 

Florida Watershed Restoration Act (FWRA) established BMPs as the primary instrument for 

implementing Florida’s TMDL program. Under the FWRA (Section 403.067, F.S.), implementation of 

BMPs that FDEP has verified as effective and Florida Department of Agriculture and Consumer Services 

(FDACS) has adopted by rule provides a presumption of compliance with state WQS. Under the program, 

landowners must maintain records and provide documentation regarding their implementation of BMPs 

and reasons why certain BMPs are not applicable to their specific situation. Exhibit ES-2 shows the 

number of acres that farmers have enrolled in the FDACS BMP program.

Exhibit ES-2: Summary of Agricultural Lands Enrolled in FDACS

BMP Program

FDACS BMP Program Type Number of Acres

Citrus 509,553

Cow/Calf 448,602

Dairies 37,535

Equine 75

Grasses 3,271

Leatherleaf Ferns 144

Nursery 20,662

Poultry Feeding Operations 312

Row Crops 754,713

Sod Farms 33,813

Specialty Farms 306

Tri-County Agricultural Area 3,841

Total 1,812,827

Source: Based on GIS analysis of 2010 FDACS data on enrollments.

Many of these acres are in the Lake Okeechobee watershed where a number of regulations require 

farmers to implement BMPs to control dischargers of phosphorus to the watershed.

Forestry

Florida’s Division of Forestry (FDOF) controls nonpoint forestry discharges of nutrients through the 

implementation of BMPs, as developed by the BMP Technical Advisory Committee and published in the 

Silviculture Best Management Practices Manual (FDOF, 2009). According to the manual, the BMPs 

reflect “the minimum standards necessary for protecting and maintaining the State’s water quality as well 

as certain wildlife habitat values, during forestry activities,” and address many sources of pollution 

including sedimentation, nutrients, and turbidity. 

FDOF periodically conducts state-wide surveys of silviculture practices to assess compliance levels, 

identify areas and foresters in need of further education, and evaluate the effectiveness of BMPs. There 

have been 15 surveys since 1984, with the most recent in 2009. Over that period, the average compliance 

rate for all BMPs was 94%, with 84% in 1985 and 98% compliance in 2009. The 2009 survey also 
November 2010 Executive Summary ES-4

reported that the implemented BMPs are generally effective at preventing significant impacts to the 

relevant waterbodies (FDOF, 2010). 

Septic Systems

According to a Florida Department of Health database, there are a total of 935,203 septic systems in 

Florida, of which 793,697 are active (FDOH, 2010a). Most of Florida’s septic systems are over 30 years 

old and were installed under standards less stringent than current standards for septic system installations. 

As a result, Florida has identified approximately $10.3 billion in capital needs to address water quality or 

water quality-related public health problems from decentralized wastewater treatment systems (U.S. EPA, 

2010b). These costs represent capital expenditures associated with the rehabilitation or replacement of 

septic systems and clustered (community) systems.

In Florida, the Bureau of Onsite Sewage Programs in the Florida Department of Health (FDOH) and the 

environmental health section of County Health Departments regulate the use of onsite sewage treatment 

and disposal systems (OSTDSs). Unless FDOH has granted a variance, it does not permit the use of an 

OSTDS where the estimated domestic sewage flow is over 10,000 gpd or the commercial sewage flow is 

over 5,000 gpd, where there is a likelihood that the system will receive toxic, hazardous or industrial 

wastes, where a sewer system is available, or if any system or effluent is currently regulated by FDEP. 

Summary of Baseline Requirements

To estimate the potential incremental impacts that may be indirectly associated with the rule, EPA 

assumed that the following actions have been or will be implemented in the absence of the rule, and did 

not estimate costs associated with these actions as part of this analysis: 

 Actions necessary to meet existing NPDES permit conditions for municipal and industrial 

wastewater

 Actions resulting from future TMDLs of 303(d) listed waters, draft or approved TMDLs, and 

draft or approved BMAPs

 BMPs for the forestry sector

 Controls required by the FDEP Dairy Rule and EPA CAFO regulations 

 Requirements for the Lake Okeechobee watershed

 Phase I and Phase II MS4 permits. 

EPA also estimated potential costs compared to a baseline of controls that could be needed to attain 

FDEP’s July 2009 draft numeric nutrient criteria. 

ES.3 Description of the Rule

EPA’s rule establishes numeric criteria for TN, TP, and chlorophyll-a for freshwater lakes and flowing 

waters in Florida that are not to be exceeded more than once in a three year period. Exhibit ES-3

summarizes these criteria, which vary by region (for streams) and characteristics of the waters (for lakes). 
November 2010 Executive Summary ES-5

Exhibit ES-3: Numeric Nutrient Criteria for Lakes and Flowing Waters in Florida

Region/Type of Water Chlorophyll-a 

(mg/L)

TN Criteria 

(mg/L)

TP Criteria 

(mg/L)

Nitrate + Nitrite 

Criteria (mg/L)

Colored Lakes1 0.020 1.27 0.050 NA

Clear Lakes (high alkalinity)2 0.020 1.05 0.031 NA

Clear Lakes (low alkalinity)3 0.006 0.50 0.011 NA

Panhandle East Flowing Waters NA 1.03 0.18 NA

Panhandle West Flowing Waters NA 0.67 0.06 NA

North Central Flowing Waters NA 1.87 0.30 NA

West Central Flowing Waters NA 1.65 0.49 NA

Peninsula Flowing Waters NA 1.54 0.12 NA

Springs NA NA NA 0.35

Chl-a = chlorophyll-a

Pt-Co = platinum-cobalt

NA = not applicable

TN = total nitrogen

TP = total phosphorus

1. Long-term Color > 40 Pt-Co

2. Long-term Color ≤ 40 Pt-Co and Alkalinity > 20 mg/L CaCO3. 

3. Long-term Color ≤ 40 Pt-Co and Alkalinity ≤ 20 mg/L CaCO3.

EPA’s rule allows modification of lake criteria for chlorophyll a, TN and/or TP where the baseline 

chlorophyll a criterion-magnitude as an annual geometric mean has never been exceeded and sufficient 

ambient monitoring data exist for chlorophyll a and TN and/or TP for at least the three immediately 

preceding years. Sufficient data include at least four measurements per year, with at least one 

measurement between May and September and one measurement between October and April each year. 

Modified criteria are calculated as the geometric mean of all annual geometric mean concentrations from 

at least the immediately preceding three years in a particular lake. When the TN and/or TP criteria are 

modified, the chlorophyll a criterion must also be modified to reflect the same period of record for which 

TN and/or TP criteria are evaluated. Modified TP and TN criteria may not exceed criteria applicable to 

streams to which a lake discharges.

For streams that are upstream of lakes, a more stringent downstream protection value (DPV) may apply. 

The applicable DPV for TN or TP can be either a value derived from a water quality model [e.g. 

BATHTUB; USACE (2010)] or the applicable criterion of the downstream lake. For this analysis, EPA 

used the lake criteria as the DPV of applicable flowing waters. The applicable DPVs are expressed as an 

annual geometric mean value not to be exceeded more than once in a three year period. 

ES.4 Potential Costs to Municipal WWTPs 

Point source dischargers receive water quality based effluent limitations (WQBELs) in permits based on 

analysis of reasonable potential to exceed water quality criteria. Because untreated municipal wastewater 

is typically high in nutrients, for this analysis, EPA assumed that all municipal WWTPs would receive 

WQBELs consistent with no mixing zones or dilution (i.e., criteria applied end-of-pipe). Potential 

controls that would facilitate attaining these limitations include biological nutrient removal (BNR), 

chemical precipitation, and effluent reuse. 

For this analysis, EPA also assumed that WWTPs would implement advanced BNR as the most costeffective treatment option. Although other treatment options may be able to reduce TN and TP 

concentrations below the levels achieved by BNR, those options tend to be significantly more expensive. 
November 2010 Executive Summary ES-6

EPA believes that other strategies to reduce nutrient loading to the watershed would likely be 

implemented before requiring these more expensive alternatives (in some cases, requiring dischargers to 

obtain a variance from meeting the criteria). Thus, EPA estimated the potential costs to WWTPs based on 

a range of estimated unit costs for BNR (U.S. EPA, 2008a).The results of this analysis suggest that total 

capital costs could be approximately $108 million to $219 million and annual operation and maintenance 

(O&M) costs could be approximately $12 million to $18 million (based on multiplying unit costs by flow 

reported in EPA’s PCS database for those dischargers that do not already have advanced BNR). Costs 

(annualized capital at 7% over 20 years plus annual O&M) could be approximately $22 million per year 

to $38 million per year. 

Using FDEP’s 2009 draft numeric nutrient criteria as the baseline, annual incremental costs to municipal 

WWTPs would be zero because the treatment technologies needed to achieve the FDEP draft criteria are 

the same as those needed to achieve the criteria in EPA’s rule. 

ES.5 Potential Costs to Industrial Wastewater Sources

Unlike municipal WWTPs, all industrial facilities do not necessarily discharge nitrogen or phosphorus. 

Also, although some facilities may use the same treatments as WWTPs (such as BNR and chemical 

precipitation), treatment options for reducing nutrient loads from industrial sources can vary due to 

industry- or facility-specific conditions. In some cases, industrial facilities may also be able to pursue 

options such as BMPs, product substitution, process modification or optimization, or retention pond 

installation. 

To estimate the potential costs to industrial facilities that may be indirectly associated with EPA’s rule, 

EPA first assumed that costs to facilities discharging to 303(d) listed waters or waters covered under a 

TMDL are not attributable to the rule because those costs would occur in the absence of the rule. Of the 

remaining industrial facilities, EPA estimated the costs of additional nutrient controls for a representative 

sample of facilities in different industrial categories that may be necessary to meet EPA’s criteria. EPA 

then extrapolated those representative costs to estimate the cost for the total flow associated with

potentially affected dischargers in the same industrial category. The results of this analysis suggest that 

costs (annualized capital at 7% over 20 years plus annual O&M) could be approximately $25.4 million 

per year.

Using FDEP’s 2009 draft numeric nutrient criteria as the baseline, annual incremental costs to industrial 

facilities would be zero because the treatment technologies needed to achieve the FDEP draft criteria are 

the same as those needed under EPA’s rule, even if the criteria themselves differ somewhat.. 

ES.6 Identification of Incrementally Impaired Waters and Watersheds

To identify potential costs to control nutrients from urban stormwater, agriculture, and septic systems, and 

to identify the potential costs associated with developing additional TMDLs, EPA evaluated Florida’s 

water quality monitoring database to assess which waters may be identified as impaired under EPA’s rule.

EPA analyzed the most recent five years of water quality monitoring data for each waterbody represented 

as a unique waterbody identification (WBID) number with sufficient monitoring data, and identified 

freshwater lakes and flowing waters that exceeded the numeric TN, TP, or chlorophyll-a criteria (based 

on annual geometric mean values). EPA also identified springs with a monthly geometric mean nitratenitrite concentration greater than the criterion as impaired. EPA removed from the resulting list of waters 

those that are currently listed as impaired on Florida’s 303(d) list of impaired waters, resulting in those 

waters that may be identified as impaired under EPA’s rule that are not already classified as impaired 

(referred to here as incrementally impaired waters). Exhibit ES-4 summarizes this analysis. 
November 2010 Executive Summary ES-7

Exhibit ES-4: Summary of Identification of Potential Incrementally Impaired Waters

Category Number of WBIDs Total Lake Stream1 Spring

Total in State 1,310 3,901 126 5,337

Not Listed/Covered by TMDL2 1,099 3,608 119 4,826

Nutrient Data in IWR Run 403 878 1,273 72 2,223

Sufficient Data Available4 655 930 72 1,657

Potentially Exceeding Criteria5 148 153 24 325

IWR = Impaired Waters Rule

TMDL = total maximum daily load

WBID = waterbody identification

1. Includes blackwater.

2. As reported in TMDL documents and FDEP (2009c).

3. Data within last 5 years meeting data quality requirements.

4. 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.

5. Based on annual geometric mean exceeding the applicable criterion more than once in a three year period.

To estimate the urban areas, agricultural land, and septic systems that may need controls to attain the 

numeric criteria for lakes and streams, EPA used GIS analysis to identify the watersheds [10-digit 

Hydrologic Unit Code (HUC)] associated with these incrementally waters. Each WBID in the state does 

not fall completely within a single 10-digit HUC. Thus, to ensure that lands (and sources) affecting water 

quality for each WBID are accounted for in the analysis and that incidental overlapping HUCs are not 

included, EPA identified watersheds containing at least 10% of an incrementally impaired lake or stream, 

excluding those watersheds that contain at least 10% of a lake or stream that is currently impaired or 

under a TMDL (to remove baseline impaired watersheds). For springs, EPA obtained GIS data on land 

areas where groundwater aquifers supply water to springs (spring recharge areas or springsheds) from 

FDEP’s Florida Geological Survey. EPA identified spring recharge areas potentially requiring additional 

nutrient controls as the incrementally impaired spring recharge areas identified as vulnerable to surface 

sources of contamination by the Florida Geological Survey Florida Aquifer Vulnerability Assessment. 

ES.7 Potential Costs for Urban Stormwater Controls

Some areas served by MS4s in incrementally impaired watersheds may require additional nutrient 

controls. However, it is difficult to identify the additional controls that may be necessary to attain EPA’s 

numeric nutrient criteria without site specific analysis. Full implementation of existing stormwater

management programs could be sufficient to attain EPA’s numeric nutrient criteria in some watersheds. 

In others, water quality monitoring after full implementation of existing stormwater management 

programs may indicate a need for additional controls. 

Current nutrient-related TMDLs in Florida allocate between 5% and 85% nutrient load reductions from 

stormwater sources (the average is approximately 50%). Urban stormwater controls can remove up to 

51% of TN and 75% of TP (Center for Watershed Protection, 2007). FDEP’s 1982 Stormwater Rule 

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 WQS (95% reduction for outstanding natural resource waters). In its evaluation of EPA’s 

proposed numeric nutrient criteria rule, FDEP (2010b) assumed that nutrient reductions mandated in the 

1982 Stormwater Rule would be sufficient to comply with EPA’s numeric nutrient criteria. Using this 
November 2010 Executive Summary ES-8

same assumption, EPA assumed that the amount of urban land within Phase I MS4s that may require 

additional nutrient controls could range from none [current implementation of BMPs to the maximum 

extent practicable (MEP) is sufficient] to all Phase I MS4 urban land in incrementally impaired 

watersheds developed before 1982. Under these assumptions, EPA estimated through GIS analysis that 

additional stormwater controls may be needed on up to 48,100 acres of Phase I MS4 urban land. 

Because over-application of fertilizers on lawns and gardens is the primary source of nutrient pollution 

from low density urban areas, EPA assumed that sufficient nutrient reductions could be achieved from 

low density Phase II MS4 areas and other low density urban areas not covered under EPA’s NPDES 

stormwater program by full implementation of existing regulations such as the Urban Turf Fertilizer Rule. 

For higher density Phase II MS4 urban areas and other higher density urban areas not covered under 

EPA’s NPDES stormwater program, EPA assumed that additional stormwater controls could be needed in 

incrementally impaired watersheds. Again, using FDEP’s assumption that urban lands developed after 

1982 would not need additional controls, EPA used GIS analysis to estimate that 30,700 acres of urban 

land within Phase II MS4s and 30,600 acres of urban land outside MS4s may need additional controls for 

nutrients in stormwater. 

Urban runoff can be a significant source of nutrient pollution to Florida springs. However, efficient land 

application of nitrogen is the most cost-effective means of addressing nutrients from this source. The 

Urban Turf Fertilizer Rule is an example of one such source control effort. Other pollution prevention or 

source control activities include city or county-wide ordinances and public outreach and education 

campaigns (which are already required in MS4 NPDES permits). Thus, EPA assumed that 

implementation of existing (baseline) requirements would be sufficient to reduce nitrate-nitrite loads to 

springs from urban stormwater. 

Costs for stormwater controls can vary widely and depend on the type of land requiring control. For this 

analysis, EPA estimated unit costs from data on existing stormwater projects in Florida obtained from 

FDEP (2010a). The cost of these projects ranges from $62 per acre to $60,300 per acre, with a median 

cost of $6,800 per acre. Using the median cost per acre and the estimated number of acres needing 

additional controls, EPA estimated that costs for additional nutrient controls for stormwater could range 

from $60.5 million per year to $108.0 million per year.

Using FDEP’s 2009 draft numeric nutrient criteria as the baseline, annual incremental costs to urban 

stormwater could range from $13.7 million to $27.2 million. 

ES.8 Potential Costs to Agriculture

About 19% of the land surrounding incrementally impaired waters is used for agriculture. BMPs control 

nutrient loadings from agricultural sources to lakes and flowing waters. For this analysis, EPA estimated 

the BMP programs that would be needed to attain the numeric criteria based on a study of agricultural 

BMPs to help meet TMDL targets in the Caloosahatchee River, St. Lucie River, and Lake Okeechobee 

watersheds (SWET 2008a). SWET (2008a) identified three types of BMP programs: an owner 

implemented program consisting of a set of practices that land owners might implement without 

incentives; a typical program consisting of practices that land owners might implement under a 

reasonably funded cost share program; and an alternative program of more aggressive controls to 

supplement the owner and typical programs if additional reductions are necessary. The BMPs in the 

owner implemented and typical program are similar to the BMPs adopted by FDACS. The alternative 

BMP program, which includes stormwater chemical treatment, is not yet required in the study basins 

which have significant contributions from agriculture. Thus, for this analysis, EPA assumed that nutrient 

controls for agricultural sources are best represented by the owner and typical programs. 
November 2010 Executive Summary ES-9

EPA estimated potential nutrient control costs to agriculture by using GIS analysis to assess the amount 

of land used for different categories of agricultural operations in incrementally impaired watersheds, and

the category-specific unit costs of the owner and typical BMP programs estimated by SWET (2008a). 

BMPs implemented under the FDACS program represent a level of control that is similar to the owner 

implemented and typical BMP programs. However, the level of compliance with the FDACS BMP 

program in incrementally impaired watersheds is uncertain (FDACS 2008, 2009). Therefore, EPA 

estimated a range of agricultural costs by including and excluding land enrolled in the FDACS BMP 

program. Using these assumptions, EPA estimated that the cost of additional agricultural BMPs that may 

be needed to attain EPA’s numeric nutrient criteria in lakes and streams could range from $15.1 million 

per year to $18.2 million per year. 

Agricultural practices could influence the water quality of springs many miles away because the 

groundwater aquifers that supply water to springs can be large and complex (USGS, 2010). Because 

nutrient management is a cost-effective way to reduce groundwater nitrogen and may even result in cost 

savings to farmers by reducing unnecessary fertilizer application, EPA assumed that all agricultural 

operations applying fertilizer to land would implement a nutrient management program to reduce levels of 

nitrogen in groundwater aquifers. 

To estimate the additional incremental costs for nutrient management, EPA first estimated the amount of 

agricultural land where nutrient management would be applicable. EPA identified general agriculture and 

specialty crops as agricultural categories appropriate for nutrient management. EPA then used GIS 

analysis to identify the total land area used for these two agricultural categories after removing acreage in 

watersheds that are currently impaired for nutrients or under a nutrient TMDL (i.e., the baseline). EPA 

also removed land identified as within incrementally impaired watersheds to avoid double counting costs 

for BMPs to protect lakes and streams as described above. As a result of this analysis, EPA identified 

approximately 1.1 million acres of agricultural land as potentially implementing nutrient management to 

meet the new numeric criteria (approximately 1 million acres of general agriculture and approximately 

0.12 million acres of specialty crops). Using unit costs of $10 per acre for general agriculture and $20 per 

acre for specialty crops (FL EQIP, 2009a), EPA estimated the cost for nutrient management could be 

approximately $4.7 million per year. Together with the estimated costs of additional agricultural BMPs to 

protect lakes and streams described above, total agricultural costs could range from approximately $19.9

million per year to $23.0 million per year. 

Using FDEP’s 2009 draft numeric nutrient criteria as the baseline, annual incremental costs to agriculture 

could be up to $2.1 million. 

ES.9 Potential Costs for Septic Systems

Some nutrient reductions from septic systems may be necessary for incrementally impaired waters to 

meet EPA’s numeric nutrient criteria. Properly operated and maintained systems usually provide 

treatment equivalent to secondary wastewater treatment (Petrus, 2003). However, even properly 

functioning septic systems could impact water quality. Implementation strategies could include greater 

use of inspection programs and repair of failing systems, upgrading existing systems to advanced nutrient 

removal, decentralized cluster systems where a responsible management entity 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 for this analysis that the most likely 

compliance strategy to reduce nutrients loads from septic systems will be to upgrade existing convention 

septic systems to advanced nutrient removal systems.
November 2010 Executive Summary ES-10

Septic systems in close proximity to surface waters are most likely to contribute the greatest nutrient load 

to the waterbody. Most of the existing nutrient-related TMDLs identify failing septic systems as 

contributing to nutrient impairments in surface waters. The Middle St. Johns River Nutrient TMDL 

considers wastewater from failed septic tanks within 50 feet as direct discharges of untreated wastewater 

to the stream network, and for those outside of the 50-feet boundary, FDEP combined septic system loads 

with the nonpoint source loading for residential areas (Gao, 2009). In addition, Florida Administrative 

Code requires that in most cases septic systems “shall not be located laterally within 75 feet of the 

boundaries of surface waterbodies” (FAC 64E-6.005(3)). 

EPA assumed that some septic systems located near incrementally impaired lakes and streams may be 

required to upgrade to advance nutrient removal systems. However, the distance that septic systems can 

be safely located relative to these surface waters depends on a variety of site specific factors. In 

consideration of this uncertainty, EPA conservatively assumed that septic systems located within 500 feet 

of any lake or stream in incrementally impaired watersheds may require upgrading to account for some 

downstream transport of nutrients from nearby streams that may not be classified as incrementally 

impaired. GIS analysis indicates that there are 8,224 active septic systems within 500 feet of any lake or 

stream in watersheds associated with incrementally impaired waters. 

Manufacturer estimates of capital costs to upgrade a conventional septic system to an advanced nutrient 

removal system (including installation costs) range from $2,000 per system to $6,500 per system, with 

annual O&M costs of $650 per year (Chang et al., 2010). Thus, annual costs could range from 

approximately $800 to $1,300 for each upgrade (capital costs annualized at 7% over 20 years plus annual 

O&M). Multiplying these unit costs by the total number of septic systems possibly needing upgrades 

(8,224) yields a cost estimate ranging from $6.6 million per year to $10.7 million per year.

For springs, the contribution of nitrogen from septic systems is highly uncertain and likely site specific. 

For example, Brown et al. (2008) found that the preponderance of nitrogen pollution in Florida springs 

appears to be from fertilizer sources; most of the accumulated evidence from mass balance computations 

and isotopic tracer studies suggests that mineral fertilizers, and therefore, not septic tanks and wastewater 

sprayfields, are the principal sources of nitrogen pollution in Florida springs. Thus, because EPA has 

already estimated costs for nutrient management on all crop land not already being controlled for existing 

or incremental impairments, EPA assumes that no additional controls would be needed for septic systems 

to attain the nitrate-nitrite criterion.

Using FDEP’s 2009 draft numeric nutrient criteria as the baseline, annual incremental costs to septic 

systems could range from $0.2 million to $0.3 million. 

ES.10 Government Expenditures

FDEP may incur costs associated with development of additional TMDLs. Because existing TMDLs 

cover an average of two waterbodies each, FDEP may need to develop 163 new TMDLs (325

incrementally impaired WBIDs ÷ 2 = 163 TMDLs). EPA (2001) indicates that TMDL development for 

two similar pollutants costs an average of approximately $47,000. Thus, total TMDL development cost 

could be $7.7 million, or $851,000 per year assuming FDEP adheres to its 9-year TMDL development 

cycle. 

Using FDEP’s 2009 draft numeric nutrient criteria as the baseline, annual incremental costs for TMDL 

development could be approximately $0.3 million. 
November 2010 Executive Summary ES-11

ES.11 Summary of Costs

Exhibit ES-5 summarizes the estimates of potential annual incremental control costs for each source. 

Exhibit ES-5: Estimates of Potential Annual Costs Associated with Numeric Nutrient 

Criteria (2010 dollars)

Source Sector Type of Expenditure Annual Costs (millions)

Municipal Wastewater1 BNR to reduce TN and/or TP $22.3 - $38.1

Industrial Dischargers2 BNR to reduce TN and TP; chemical 

precipitation to reduce TP $25.4

Urban Stormwater4 Stormwater controls $60.5 - $108.0

Agriculture5 Owner/typical BMP program $19.9 - $23.0

Septic Systems6 Upgrade to advanced nutrient treatment $6.6 - $10.7

Government/Program 

Implementation TMDL development7 $0.9

Total -- $135.5- $206.1

Note: Detail may not add to total due to independent rounding.

BNR = biological nutrient removal; TMDL = total maximum daily load; TN = total nitrogen; TP = total 

phosphorus

1. Based on upgrading existing treatment processes to advanced BNR.

2. Based on extrapolation of average annual costs per flow for random sample of dischargers stratified by 

industrial category.

4. Based on median stormwater control costs from FDEP (2010a), and scenario of need for structural 

controls on land developed before 1982.

5. Based on implementing nutrient management on all crop land outside of incrementally and baseline 

impaired watersheds and scenarios in which all agricultural land not enrolled in the FDACS BMP program 

in incrementally impaired watersheds incurs owner/typical program costs from SWET (2008a) or all 

agricultural land in incrementally impaired watersheds incurs owner/typical costs based on SWET (2008a).

6. Based on upgrading to advanced nutrient removal active septic systems within 500 feet of water (based on 

GIS land use data) in incrementally impaired watersheds.

7. Based on average costs to complete TMDLs for incrementally impaired waters under a 9-year schedule.

Using FDEP’s 2009 draft numeric nutrient criteria as the baseline, total annual incremental costs could 

range from $17.5 million to $27.2 million. 

ES.12 Potential Benefits

Florida waters have historically provided recreational opportunities that are a vital part of the State’s 

economy. The Florida Department of Environment (2008) reported that in 2007, over 4.3 million 

residents and over 5.8 million visitors participated in recreational activities related to freshwater beaches 

in Florida. Also, over 2.7 million residents and approximately 1 million visitors that used freshwater boat 

ramps, over 3 million residents and over 900,000 visitors participated in freshwater non-boat fishing, and 

over 2.6 million residents and almost 1 million visitors participated in canoeing and kayaking. 

Tourism comprises one of the largest sectors of the Florida economy (VISIT Florida 2010). In 2006, 

Florida ranked first in the nation for the number of in-state anglers, angler expenditures, angler-supported 

jobs. In addition, Florida’s freshwater springs are an important inter- and intra-state tourist attraction. In 

2002, Blue Springs State Park estimated over 300,000 visitors per year. 

Nutrient pollution has contributed to severe water quality degradation of Florida waters. In 2010, the State 

of Florida reported approximately 1,918 miles of rivers and streams, and 378,435 acres of lakes that were 
November 2010 Executive Summary ES-12

known to be impaired by nutrient pollution (FDEP 2010; the actual number of waters impaired for 

nutrients may be higher because many waters were not assessed). As water quality declines, water 

resources have less recreational value. Waters impaired by nutrient pollution may become unsuitable for 

swimming and fishing, and in some cases unsuitable for boating. Nutrient-impaired waters also are less 

likely to support native plant and animal species, further lowering their value as tourist destinations. 

Drinking water supplies may also be more expensive to treat as a result of nutrient impairments. Also, 

Florida citizens that depend on individual wells for their drinking water may need to consider whether onsite treatment is necessary to reduce elevated nitrogen levels. Freshwater springs are particularly at risk. 

Silver Springs, the largest of Florida’s springs, has experienced reduced ecosystem health and 

productivity over the past half century, due largely to excessive nitrate and nitrite. Nutrient impairment, 

characterized by algal blooms, reduced numbers of native species, and lower water quality, in turn leads 

to reduced demand and lower values for these resources. 

Reducing excess nitrogen in water can result in significant economic benefits to Florida citizens. These 

benefits include maintenance of Florida’s valuable freshwater fishing and ecotourism industries and 

increased lakeshore and near-lakeshore property values. There could also be significant indirect economic 

benefits including reduction in healthcare costs (due to avoided harmful algal blooms), cleaner drinking 

water sources resulting in reduced water treatment costs. Other indirect economic benefits include the 

avoidance of costs associated with the need to find alternative recreational locations, enhanced 

opportunities for angling competitions, wildlife watching, and camping, and non-use values such as 

habitat protection. Numeric nutrient criteria can also result in avoidance of future restoration costs 

because numeric criteria are easily measurable qualities of water that can be used to assess whether or not 

waters are in danger of becoming impaired.

Some of the benefits of reducing nutrients can be monetized, at least in part, by translating changes in 

nutrient concentrations into an indicator of overall water quality (a water quality index, WQI) and valuing 

these improvements in terms of willingness to pay (WTP) for the types of uses that are supported by 

different water quality levels. To monetize benefits in this way EPA used an approach that links specific 

pollutant levels with suitability for particular recreational uses. The parameters used to formulate the WQI 

are based on waterbody type, scientific understanding of ecosystem response to varying conditions, and 

available data. To estimate benefits of water quality improvements associated with EPA’s criteria, EPA 

calculated the post-compliance WQI assuming that all incrementally impaired waterbodies meet the 

numeric nutrient criterion, and that there are no water quality improvements in any non-incrementally 

impaired waterbodies. The difference in WQI between baseline conditions and compliance with the 

numeric TN and TP criteria is a measure of the change in water quality that may be attributable to the 

rule. EPA then conducted a regression analysis to determine average household Willingness to Pay 

(WTP) for increases in water quality. EPA calculated the average household WTP at the WBID-level for 

both full-time and part-time residents. EPA estimated total benefits at the WBID level by multiplying 

average household WTP with the number of households in each category and the percentage of miles or 

area that comprise a given WBID. As presented in Exhibit ES-6, EPA estimated total state benefits using 

current conditions as the baseline to be approximately $28.1 million per year ($21.6 million of 

improvements in flowing waters plus $6.56 million for improvements in lakes, using midpoint estimates).

Although these monetized benefits estimates do not account for all potential economic benefits, they help 

to demonstrate the economic importance of restoring and protecting Florida waters from the impacts of 

nutrient pollution. 
November 2010 Executive Summary ES-13

Exhibit ES-6: Estimated Total Average Annual Benefits for Water Quality Improvement 

to Freshwater Flowing Waters and Lakes in Florida (millions of 2010 dollars per year)

State Resident Type Flowing Waters Lakes Total

Full Time FL Residents $21.3 $6.5 $27.8

Part Time Winter Residents $0.3 $0.1 $0.4

Total $21.6 $6.6 $28.2
November 2010 1. Introduction 1-1

1. Introduction 

The U.S. Environmental Protection Agency (EPA) is promulgating numeric nutrient criteria applicable to 

freshwater lakes and flowing waters in the state of Florida. EPA’s criteria will augment the state’s 

existing narrative nutrient criteria. Although this rule does not establish any requirements directly 

applicable to regulated entities or other sources of nutrient pollution, state implementation may result in 

new or revised National Pollutant Discharge Elimination System (NPDES) permit conditions for point 

source dischargers and/or requirements for nutrient pollution treatment controls on other sources. To 

provide information on the potential incremental costs associated with these related state actions, EPA 

conducted an analysis on the control costs and benefits associated with state actions that may be necessary 

to assure attainment of state water quality designated uses supported by the criteria in EPA’s rule. 

1.1 Requirement for the Rule

Section 303(c) of the Clean Water Act (CWA) requires states to adopt WQS for waters of the United 

States within their applicable jurisdictions. Section 303(c)(2)(A) and EPA’s implementing regulations at 

40 CFR part 131 require that state WQS include the designated use or uses to be made of the waters and 

the criteria necessary to protect those uses. EPA’s 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.”

CWA section 303(c) also requires states to review their WQS at least once every three years and, if 

appropriate, revise or adopt new standards. States must submit these new or revised WQS to EPA for 

review and approval or disapproval. Section 303(c) also directs the EPA Administrator to promulgate 

WQS to supersede state standards that it has disapproved or in cases where it determines that a new or 

revised standard is needed to meet CWA requirements.

The state of Florida currently uses a narrative criterion to protect waters from nutrient pollution. In 

January of 2009, EPA determined that new or revised WQS for nutrients in the form of numeric nutrient 

criteria are necessary in Florida to meet the requirements of the CWA (U.S. EPA, 2009a). In August of 

2009 EPA entered into a phased Consent Decree with several environmental organizations that

challenged the Agency for not having promulgated numeric nutrient criteria for the State of Florida. In 

that Consent Decree, EPA committed to issue a final numeric nutrient rule for Florida’s inland waters by 

October 15, 2010, which was subsequently extended to November 14, 2010. This rule will satisfy that 

requirement of the Consent Decree. 

1.2 Purpose and Scope of the Analysis 

The rule establishes water quality criteria applicable to lakes and flowing waters in defined regions within 

Florida. The rule does not establish any requirements directly applicable to regulated entities or other 

sources of nutrient pollution to these waters. Nonetheless, state implementation of the criteria may result 

in new or revised National Pollutant Discharge Elimination System (NPDES) permit conditions for point 

source dischargers and nutrient control requirements on other sources (e.g., agriculture, urban runoff, and 

septic systems). Therefore, the purpose of this analysis is to provide estimates (within the limits of 

uncertainties regarding implementation) of the potential costs and benefits that may ultimately be 
November 2010 1. Introduction 1-2

associated with the modified criteria to inform the public regarding these potential impacts. Actual 

impacts will depend on the particular implementation strategy pursued by the state. 

This report provides an assessment of the potential costs associated with implementation of EPA’s final 

rule above and beyond the costs that may result without the rule. EPA believes that the requirements 

currently in place represent a useful baseline from which to evaluate potential actions that may be 

necessary to attain these criteria. However, in July of 2009 the state of Florida released draft numeric 

nutrient criteria for lakes and flowing waters. Although the state of Florida subsequently did not proceed 

forward with those numeric criteria provisions, EPA evaluated the incremental impacts of its proposed 

rule in January 2010 using the Florida July 2009 draft criteria as the baseline. To similarly illustrate the 

difference between Florida’s draft approach and the provisions of this final rule, EPA has conducted the 

same evaluation as part of this economic analysis. Appendix A provides estimates of potential

incremental costs relevant to this alternative baseline. 

It is possible that implementation of the narrative criteria would eventually lead to imposition of controls

deemed necessary to comply with EPA’s numeric nutrient criteria because both criteria target the same 

endpoint of “no imbalance of flora and fauna,” such that the difference in costs is just a matter of timing. 

Under such a scenario, EPA’s rule may result in cost savings by addressing the need for controls sooner 

rather than later and avoiding more costly restoration. However, with this analysis, EPA is conveying 

information related to the potential costs and benefits of implementing its numeric nutrient criteria as an 

“increment” to the costs and benefits associated with ongoing efforts to implement the existing narrative 

criterion. EPA refers to these existing conditions and requirements (e.g., narrative nutrient criterion, 

actions required under existing nutrient-related TMDLs) as the “baseline.”

To identify the potential incremental impact above the baseline for the rule, EPA evaluated potential 

changes to NPDES permit conditions for municipal and industrial wastewater facilities since these point 

sources may receive water quality based effluent limitations (WQBELs). For nonpoint sources, EPA 

identified waters that may not meet EPA’s criteria but are not currently listed by the state as impaired for 

nutrient-related causes, and used land use data surrounding incrementally impaired watersheds (that are 

not also in baseline impaired watersheds) as an indication of the types of controls that will be needed to 

attain the criteria. EPA based its estimates of the types of controls and costs for different sources that may 

be needed on those currently being required throughout the state in watersheds impaired under the 

narrative criterion. The data and methods behind each of these components of the analysis are described 

in detail within the report and appendices. 

In addition, this analysis provides a description of the types and categories of benefits associated with 

attaining and maintaining nutrient criteria in lakes and flowing waters in Florida, and estimates of the 

potential magnitude of benefits that may be associated with the rule based on a benefits transfer approach. 

Numeric nutrient criteria provide a means of developing protective numeric effluent limits for wastewater 

point sources. Numeric nutrient criteria also provide information that may help in limiting loads from 

nonpoint sources to prevent impairment in waters that do not yet exceed the criteria. Thus, there is 

potential for benefits from attaining designated uses where such uses are impaired and protecting 

designated uses from future impairment and the associated loss of value. However, the estimates of costs 

and benefits in this report do not account for prevention of future impairments. 

1.3 Organization of this Report

The remainder of this report is organized as follows:

 Section 2 describes the baseline for estimating potential incremental compliance actions.
November 2010 1. Introduction 1-3

 Section 3 provides a description of the rule, and potential implementation. 

 Section 4 provides estimates of controls and costs for wastewater point source dischargers. 

 Section 5 provides estimates of controls and costs for industrial point sources. 

 Section 6 identifies potentially impaired waters under the rule. 

 Section 7 provides discussion of the potential for incremental controls for urban runoff. 

 Section 8 provides estimates of controls and costs for agriculture. 

 Section 9 provides estimates of controls and costs for septic systems.

 Section 10 provides estimates of government expenditures. 

 Section 11 summarizes the potential costs and describes the uncertainties of the analysis.

 Section 12 provides qualitative and quantitative analyses of potential benefits. 

 Section 13 provides monetized estimates of potential benefits. 

 Section 14 provides references.

 Appendix A provides an assessment of incremental impairments and costs of the rule compared 

to an alternative baseline represented by FDEP’s July 2009 draft numeric nutrient criteria. 

 Appendix B provides a sensitivity analysis of the potential impact on the estimated costs of 

assumptions related to the downstream protection values (DPVs) for lakes. 

 Appendix C provides discharger-level detail of estimated municipal wastewater costs.

 Appendix D provides detailed analyses for the sample of industrial dischargers.

 Appendix E provides discussion of the potential effect of nutrient criteria on response indicators 

and biota. 

 Appendix F provides an analysis of quantitative benefits associated with improvements in 

dissolved oxygen levels. 
November 2010 2. Baseline for the Analysis 2-1 

2. Baseline for the Analysis

As described in Section 1, this report conveys information related to the potential costs and benefits of 

implementing EPA’s numeric nutrient criteria as an “increment” to ongoing efforts to implement 

Florida’s existing narrative criterion. This section describes the baseline conditions, including the 

regulatory framework, pollution controls, and water quality. Because a number of existing programs and 

requirements are not fully implemented, existing water quality may not accurately represent the ultimate 

conditions that would result without the rule. This section describes the information and assumptions EPA 

used to establish the baseline for identifying the incremental requirements and costs that may be 

associated with EPA’s numeric nutrient criteria for lakes, streams, and springs in Florida. 

2.1 Current Regulatory Framework

The current regulatory framework for controlling nutrients in Florida waters includes existing WQS, and 

state and federal requirements for dischargers of nutrients.

2.1.1 Water Quality Standards

WQS include designated uses of waters (e.g., aquatic life support, recreation, drinking water), water 

quality criteria to protect the uses, and antidegradation policy. WQS also include implementation 

procedures, specifically addressing identification of impaired waters, to the extent the procedures further 

define designated uses and protective criteria.

Current Water Quality Criteria

For nutrients, FDEP water quality criteria are narrative in form: Chapter 62-302.530, Florida 

Administrative Code (F.A.C.), states that “in no case shall nutrient concentrations of a body of water be 

altered so as to cause an imbalance in natural populations of flora or fauna.” EPA’s numeric nutrient 

criteria address this aspect of the narrative criterion. The narrative criterion also states that (for all waters 

of the state) “the discharge of nutrients shall continue to be limited as needed to prevent violations of 

other standards contained in this chapter (Chapter 62-302, F.A.C.). Man-induced nutrient enrichment 

(total nitrogen or total phosphorus) shall be considered degradation in relation to the provisions of 

Sections 62-302.300, 62-302.700, and 62-4.242, F.A.C.” The principle of “other standard” referred to in 

this aspect of Florida’s narrative is dissolved oxygen (DO). EPA expects that achieving the promulgated 

numeric nutrient criteria will also maintain DO levels consistent with Florida WQS in most cases;

however, there remains the potential that the existing narrative criteria may need to be utilized to lower 

nitrogen and phosphorus levels further in specific waters.

CWA Section 303(d) Listing Procedures 

The WQS also contain procedures for identifying impaired waters. FDEP first evaluates the existing 

water quality data to determine whether waters are potentially impaired and includes these waters on a 

Planning List for further assessment. FDEP then assesses waters on the Planning List through additional 

data gathering and strategic monitoring to determine if a waterbody is impaired and if the impairment is 

caused by pollutant discharges. FDEP places these waters on the Verified List which are included in the 

CWA Section 303(d) list of impaired waters that require a TMDL. 

FDEP uses a trophic state index (TSI) and chlorophyll-a concentration as the primary means for assessing 

whether a waterbody should be assessed further for nutrient impairment. TSI measures the potential for 

algal or aquatic weed growth; its components include total nitrogen, total phosphorus, and chlorophyll.
November 2010 2. Baseline for the Analysis 2-2 

FDEP also considers other information indicating an imbalance in flora or fauna due to nutrient 

enrichment, including, but not limited to, algal blooms, excessive macrophyte growth, decrease in the 

distribution (either in density or areal coverage) of seagrass or other submerged aquatic vegetation, 

changes in algal species richness, and excessive diel oxygen swings (Chapter 62-303, F.A.C.). 

For example, a stream (which includes springs FDEP classifies as surface waters) shall be included on the 

planning list for nutrients if (Chapter 62-303.351, F.A.C.): 

 algal mats are present in sufficient quantities to pose a nuisance or hinder reproduction of a 

threatened or endangered species, or

 the annual mean chlorophyll-a concentration is greater than 20 μg/L or if data indicate that annual 

mean chlorophyll-a values have increased by more than 50% over historical values for at least 

two consecutive years.

A lake shall be included on the planning list for nutrients for any of the following (Chapter 62-303.352, 

F.A.C.): 

 for lakes with a mean color greater than 40 platinum cobalt (Pt-Co) units, the annual mean TSI 

for the lake exceeds 60, unless paleolimnological information indicates the lake was naturally 

greater than 60

 for lakes with a mean color less than or equal to 40 Pt-Co units, the annual mean TSI for the lake 

exceeds 40, unless paleolimnological information indicates the lake was naturally greater than 40 

 for any lake, data indicate that annual mean TSIs have increased over the assessment period, as 

indicated by a positive slope in the means plotted versus time, or the annual mean TSI has 

increased by more than 10 units over historical values. 

To be placed on the verified list, FDEP requires sufficient data from the last five years preceding the 

planning list assessment, combined with historical data (if needed to establish historical chlorophyll-a 

levels or historical TSIs). If data are sufficient, FDEP needs to collect additional data to meet the 

requirements. Once these additional data are collected, FDEP determines if there is sufficient information 

to develop a site specific threshold that better reflects conditions beyond which an imbalance in flora or 

fauna occurs in the water. If there is insufficient information, FDEP will reevaluate the data using the 

thresholds from the planning list. However, FDEP need not use these same thresholds in developing the 

TMDL.

Proposed Revisions to Nutrient Standards

In July 2009, FDEP published draft changes to its nutrient WQS (Chapters 62-302 and 62-303) to put in 

place numeric limits for phosphorus and nitrogen with plans to submit its numeric nutrient criteria to the 

Florida Environmental Regulation Commission by 2011 (State of Florida Numeric Nutrient Criteria 

Development Plan, FDEP 2009a). The numeric nutrient criteria for total nitrogen (TN) and total 

phosphorus (TP) are based on color for lakes and region for flowing waters (Exhibit 2-1) 
November 2010 2. Baseline for the Analysis 2-3 

Exhibit 2-1: FDEP July 2009 Draft Numeric Nutrient Criteria for Lakes and Streams

Region/Type of Water

TN Annual 

Geometric Mean 

Criteria (mg/L)

TP Annual 

Geometric Mean 

Criteria (mg/L)

Nitrate + Nitrite 

Monthly Median 

Criteria (mg/L)

Clear Lakes, < 50 mg/L CaCO3

1 0.85 0.015 NA

Clear Lakes, > 50 mg/L CaCO3 1.0 0.030 NA

Colored Lakes1 1.23 0.050 NA

Panhandle Streams 0.82 0.069 NA

Northeast Streams 1.72 0.101 NA

North Central Streams 1.72 0.359 NA

Peninsula Streams 1.72 0.119 NA

Bone Valley Streams 1.72 0.75 NA

Springs NA NA 0.35

mg/L = milligrams per liter

NA = not applicable

Pt-Co = platinum-cobalt

TN = total nitrogen

TP = total phosphorus

1. FDEP (2009b) indicates color >40 Pt-Co is a colored lake; color <40 Pt-Co is a clear lake.

2. FDEP proposed a monthly median nitrate-nitrite criterion for clear flowing waters (which includes 

springs) that applies in months when the median color is less than 40 Pt-Co and is not to be exceeded more 

than 10% of the time (unless a site specific alternative criterion has been adopted).

FDEP also proposed to adopt many TMDL targets and allocations as site specific criteria.

For lakes, impairment is based on exceeding the annual geometric mean criteria more than once in any 

three calendar year period. For streams, the draft impairment procedures refer to a section that is missing, 

making it unclear how impairment would be determined for streams. For consistency with lakes, EPA 

assumed that more than one exceedance in a three year period would result in a stream being listed as 

impaired. Ambient geometric means shall be based on at least four total measurements, with at least one 

measurement taken between May and September and one measurement taken between October and April. 

2.1.2 Restoration of Designated Uses in Impaired Waters

FDEP is implementing its current narrative nutrient criteria through TMDLs and the NPDES permit 

program (see Section 2.1.3). A TMDL is a calculation of the maximum amount of a given pollutant that a 

surface water can receive and still meet WQS, and an allocation of that amount to point and nonpoint 

source categories. Because the existing nutrient criteria are narrative, FDEP typically uses site specific

data to translate the narrative criteria into numeric concentration targets, numeric load targets, or percent 

reduction requirements. Numeric nutrient concentration targets in TMDLs for TN and TP in freshwater 

lakes and flowing waters range from 0.6 mg/L to 3.0 mg/L and 0.015 mg/L to 0.16 mg/L, respectively. 

To implement TMDLs, FDEP may develop Basin Management Action Plans (BMAPs) with local 

stakeholders. State law requires FDEP to adopt BMAPs by Secretarial Order. These Orders are 

enforceable. BMAPs set forth the strategy for achieving the pollutant reductions established in the 

TMDL, including permit limits on wastewater facilities, urban and agricultural best management practices

(BMPs), conservation programs, financial assistance, and revenue generating activities. 

FDEP has adopted five nutrient BMAPs to date (Upper Ocklawaha, Orange Creek, Long Branch, Lower 

St. John’s River (LSJR), and Lake Jesup) that address broad areas. For example, implementation of the 
November 2010 2. Baseline for the Analysis 2-4 

Upper Ocklawaha BMAP addresses surface waters throughout Lake County and part of Orange County, 

including the Clermont Chain of Lakes connected by the Palatlakaha River, Lake Apopka, Lake Griffin, 

and the Harris Chain of Lakes. Similarly, the Orange Creek Basin is a tributary of the Ocklawaha River. 

Implementation of the Orange Creek BMAP addresses surface waters in Alachua and Marion Counties, 

including Orange Lake, Lochloosa Lake, Newnans Lake, Tumblin Creek, Sweetwater Branch, Hogtown 

Creek, Lake Wauberg, Paynes Prairie/Alachua Sink, and the Ocklawaha River.

Exhibit 2-2 provides a summary of the source categories and implementation measures proposed in the 

completed BMAPs.

Exhibit 2-2: Summary of Completed Nutrient Basin Management Action Plans

BMAP (Date) Description Sources/Controls

Lake Jesup 

(2010)

No. of WBIDs: 2

Pollutants targeted: TP (actions

will achieve TN reductions)

Targets: TP = 0.096 mg/L; TN = 

1.27 mg/L

Implementation Plan: Necessary 

reductions spread over 15-year 

period; current BMAP only 

addresses reductions for the first 

5-year period. 

Municipal WWTPs: City of Samford Site 10 (only 

source) has discontinued application of biosolids and 

will reduce the use of reclaimed water on the site. 

Urban: implement BMPs through existing MS4 

permits (15 of 17 entities have MS4 permits)

Agriculture: 100% of targeted citrus, nurseries row 

crops, sod, and horse farms and cow/calf operations 

enrolled in FDACS BMP program in 5 years

Septic Systems: Studies to better determine 

contributions; remove tanks <75 feet from waters in 

certain areas

Long Branch 

(2008) 

No. of WBIDs: 1

Pollutants targeted: TN and TP

Targets: TP = 0.14 mg/L; TN = 

0.87 mg/L

Implementation Plan: Unable to 

identify specific sources. Focus on 

implementation of existing 

programs and studies to identify 

sources; as such the TMDL will 

not be achieved in the near term. 

Industrial Dischargers: Orlando Speedworld will 

identify procedures in place to ensure proper 

management of wastewater during events

Agriculture: continue implementation of FDACS 

BMP manuals

Urban: continue implementation of MS4 permits; 

Septic Systems: Sanitary survey to determine 

contributions to nutrient loads

Lower St. Johns 

River (2008) 

No. of WBIDs: 5 (freshwater); 8

(marine)

Pollutants targeted: TN and TP

Targets: concentration targets not 

specified for freshwater portion; 

TN = 5.4 mg/L for marine

Implementation Plan: Reductions 

needed from point and nonpoint 

sources; full implementation of 

BMAP and achieving TMDL will 

take many years. 

Municipal WWTPs: Allows for aggregate permits 

(combined allocations with MS4 allocations); likely 

requires upgrade to advanced water treatment. 

Industrial Dischargers: Industrial effluent monitoring 

at Seminole Electric and other industrial sources

Agriculture: Implement FDACS BMP manuals; 

regional stormwater facilities

Urban: Continue implementation of MS4 permits; 

designate certain non-MS4 areas as Phase II MS4s; 

voluntary permit trading scheme

Septic Systems: Phase-out projects
November 2010 2. Baseline for the Analysis 2-5 

Exhibit 2-2: Summary of Completed Nutrient Basin Management Action Plans

BMAP (Date) Description Sources/Controls

Orange Creek 

(2008) 

No. of WBIDs: 4

Pollutants targeted: TN and TP

Targets: 0.031 mg/L to 0.16 mg/L 

for TP; 0.97 mg/L to 1.48 mg/L 

for TN

Implementation Plan: Most 

activities recently completed or 

currently ongoing; several key 

projects/studies may extend past

first 5-year cycle, and TMDLs may 

not be achieved in the near term.

Municipal WWTPs: Gainesville Regional Utilities

(only source) to implement wastewater reuse and 

restoration of collection system to minimize releases. 

Industrial Dischargers: Small power plant will monitor 

discharges

Agriculture: Implement FDACS BMP manuals; 

cooperation with private sector for implementation 

and monitoring

Urban: Continue implementation of MS4 permit

Septic Systems: Evaluation/studies of septic tanks in 

areas where most prevalent

Upper 

Ocklawaha 

(2007) 

No. of WBIDs: 18

Pollutants targeted: TP (actions

will achieve TN reductions)

Targets: 0.02 mg/L to 0.055 mg/L 

TP; TN = 0.78 mg/L (1 TMDL) 

Implementation Plan: Most 

activities recently completed or 

currently ongoing; several key 

projects/studies may extend past

first 5-year cycle, and TMDLs may 

not be achieved in the near term.

Agriculture: Implement FDACS BMP manuals; 

Marion County Clean Farms Initiative

Urban: Continue implementation of MS4 permits 

(includes stormwater retrofits most of which were 

started or completed before final BMAP published); 

Orange County agreement with Parks Department to 

reduce use of phosphorus fertilizer and herbicide 

applications on all parklands

Septic Systems: Ordinances for tank maintenance (not 

directly addressed in first phase because relatively 

small percent of load)

Other: Nutrient reduction facility to treat releases

from Lake Apopka; harvesting gizzard shad to reduce 

recycling of nutrients; re-establishing natural water 

level fluctuations and flows; restoring aquatic/wetland 

habitats at former muck farms; most projects started 

prior to BMAP (ongoing)

BMAP = Basin management action plan

BMPs = Best management practices

FDACS = Florida Department of Agriculture and Consumer Service

MS4 = municipal separate storm sewer system

TMDL = total maximum daily load

TN = total nitrogen

TP = total phosphorus

WBID = waterbody identification

The BMAPs rely heavily on existing programs [e.g., NPDES program, BMP manuals (see Section 2.1.5)]. 

For example, existing BMAPs for the LSJR, Orange Creek watershed, and Upper Ocklawaha River rely 

on voluntary implementation of BMPs by farmers through the Florida Department of Agriculture and 

Consumer Services (FDACS) BMP program. However, Subsection 403.067(7)(b), F.S., requires that 

nonpoint pollutant sources (such as agriculture) included in a BMAP demonstrate compliance with 

pollutant reductions established to meet a TMDL either by implementing BMPs or by conducting water 

quality monitoring prescribed by FDEP or a water management district. Thus, if necessary, farmers could 

be required to implement approved BMPs. 

Note that a June 2008 FDEP Office of Inspector General (OIG) audit of the TMDL program indicated 

that the Ocklawaha River is the only waterbody currently undergoing BMAP implementation, no 
November 2010 2. Baseline for the Analysis 2-6 

waterbodies have been removed from the impaired list, and it may take a number of years before 

demonstrable effects of the program can be measured and FDEP removes waterbodies from the impaired 

waters list (FDEP OIG, 2008). Factors that may affect the progress of implementation include the time it 

takes for local governments and residents to reach consensus on difficult issues, and the time it takes to 

acquire the necessary land (FDEP OIG, 2008).

2.1.3 Existing Regulations for Point Source Dischargers

Rules 62-620.320(1) and 62-620.620(1)(g), F.A.C., establish that a permit shall be issued only if the 

applicant affirmatively provides FDEP with reasonable assurance (RA) that the construction, 

modification, or operation of the discharge facility will not discharge or cause pollution in contravention 

of WQS. As part of the permit application process, the applicant must supply data characterizing the 

pollutants that may be discharged and provide RA that the discharge will not violate water quality criteria 

in the receiving water.

FDEP’s permit writer’s guidance manual (FDEP, 2006a) indicates that at a minimum permit writers 

should include limits in permits for a parameter if there is evidence that the discharge could cause or 

contribute to instream violations. However, FDEP may include limits based on EPA’s reasonable 

potential approach, which requires sufficient effluent data as described in its Technical Support Document 

(TSD) (U.S. EPA, 1991), or based on the judgment of the permit writer that a limit is necessary to provide 

RA that the facility will operate in a way that will not cause water quality violations (FDEP, 2006a). For 

example, for the current narrative nutrient criterion, permit writers determine whether the discharge 

contains phosphorus or nitrogen and examine the ambient water quality of the receiving water and any 

other affected waters with regard to nutrient levels and biological impacts. 

Based on this analysis, permit writers determine the level of nutrients 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. If there is reasonable potential, permit writers calculate 

permit limits to ensure that such a discharge will not cause or contribute to an exceedance of the nutrient 

target levels. FDEP’s permit writer’s guidance manual (FDEP, 2006a) indicates that water quality based 

effluent limits (WQBELs) are calculated based on EPA’s TSD (U.S. EPA, 1991). If sufficient data are not 

available to determine reasonable potential, the permit can be issued with an effluent limit based on 

Florida’s water quality criteria and an administrative order attached to the permit that requires the studies 

necessary to determine RA with a schedule to return the facility to compliance with the final permit limits 

(FDEP, 2006a).

2.1.4 Existing Regulations for Urban Areas

Stormwater runoff from urban areas may contain phosphorus and nitrogen, primarily from fertilizers 

applied to lawns and golf courses, decomposition of natural rock and soils, air deposition from vehicle 

exhaust or power plants, detergents used to wash cars on the street, and pet waste. A number of rules and 

programs regulate discharges from urban areas.

Urban Turf Fertilizer Rule

To address nutrients from fertilizers, the FDACS adopted the statewide Urban Turf Fertilizer Rule, which 

limits the phosphorus and nitrogen content in fertilizers for urban turf and lawns. The rule requires that all 

fertilizer products labeled for use on urban turf, sports turf, and lawns be limited to the amount of nitrogen 

and phosphorus needed to support healthy turf maintenance. FDACS estimated a 20% to 25% reduction 
November 2010 2. Baseline for the Analysis 2-7 

in nitrogen and a 15% reduction in phosphorus in every bag of fertilizer sold to the public. The rule also 

protects water quality by restricting phosphorous and nitrogen application rates in fertilizers.2 The rule 

became effective December 31, 2007, with a requirement for fertilizer labels to reflect compliance by July 

1, 2009. 

EPA Stormwater Program

EPA’s Phase I stormwater rule covers large and medium-size MS4s [Clean Water Act Section 402(p) 

sources], and the Phase II rule covers small MS4s (systems serving less than 100,000 people). Generally, 

Phase I MS4s are covered by individual permits and Phase II MS4s are covered by a general permit.

There are 28 Phase I NPDES MS4 permits in Florida and 131 Phase II permittees. 

Each regulated MS4 is required to develop and implement a stormwater management program (SWMP) 

to reduce the contamination of stormwater runoff and prohibit illicit discharges. The MS4 Program 

contains elements called minimum control measures that when implemented should result in a significant 

reduction in pollutants discharged into receiving waters:

 Public Education/Outreach – includes educating the community on the pollution potential of 

common activities, increasing awareness of the direct links between land activities, rainfallrunoff, storm drains, and local water resources, and providing the public clear guidance on steps 

and specific actions that they can take to reduce their stormwater pollution-potential through use 

of brochures/pamphlets, mailers, posters, and training for local business employees 

 Participation/Involvement – build on community capital to help spread the message on preventing 

stormwater pollution, to undertake group activities that highlight storm drain pollution, and 

contribute volunteer community actions to restore and protect local water resources; includes 

facilitating opportunities for direct action, educational, and volunteer programs such as riparian 

planting days, volunteer monitoring programs, storm drain marking, or stream-clean up programs 

 Illicit Discharge Detection and Elimination – develop a program to detect and eliminate illicit 

discharges which primarily includes developing a storm sewer system map, an ordinance 

prohibiting illicit discharges, a plan to detect and address these illicit discharges, and an education 

program on the hazards associated with illicit discharges

 Construction Site Runoff Control – develop a program to reduce pollutants in stormwater runoff 

for construction sites disturbing one or more acres which primarily includes developing an 

ordinance, requirements to implement erosion and sediment control BMPs, requirements to 

control other waste at the construction site, procedures for reviewing construction site plans, 

procedures to receive and consider information submitted by the public, and procedures for 

inspections and enforcement of stormwater requirements at construction sites. 

 Post-Construction Runoff Control – address post-construction stormwater runoff from new 

development and redevelopments that disturb one or more acres which primarily includes 

 

2 A maximum of 0.25 lbs phosphorus oxide (P2O5) per 1000 sq. ft. per application and not to exceed 0.5 lbs P2O5 per 1000 sq. ft. 

per year. Application rates above these levels would require a soil sample of the application site to justify an increase in P2O5. A 

maximum of 0.7 lbs of readily available nitrogen per 1000 sq. ft. at any one time based on the soluble fraction of nitrogen 

formulated in the fertilizer. A maximum of 1 lb TN per 1000 sq. ft. to be applied at any one time, not exceeding the annual 

nitrogen recommendations in the Fertilizer Guidelines for Established Turf Grass Lawns in Three Regions of Florida. 

Application rates above these levels would require a turf tissue test at the application site to justify the increase in TN.
November 2010 2. Baseline for the Analysis 2-8 

developing strategies to implement a combination of structural and non-structural BMPs, an 

ordinance to address post-construction runoff, and a program to ensure adequate long-term 

operation and maintenance of BMPs. 

 Pollution Prevention/Good Housekeeping - develop inspection and maintenance procedures and 

schedules for stormwater BMPs, implement BMPs to treat pollutants from transportation 

infrastructure, maintenance areas, storage yards, sand and salt storage areas, and waste transfer 

stations, establish procedures for properly disposing of pollutants removed from the MS4, and 

identify ways to incorporate water quality controls into new and existing flood management 

projects.

Florida Stormwater Rule

Florida’s 1982 stormwater rule [as authorized in Chapter 403, Florida Statues (F.S.)] requires treatment of 

stormwater from new development and redevelopment prior to discharge. The rule is a technology-based 

program that relies on the implementation of BMPs designed to achieve a specific level of treatment (i.e., 

performance standards). 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 stormwater pollutant 

load reduction goals to be adopted as part of a Surface Water Improvement and Management (SWIM) 

plan, other watershed plan, or rule. 

In addition, Chapter 62-40, F.A.C., “Water Resource Implementation Rule,” 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 WQS (95% reduction for 

outstanding natural resource waters). The rule also states that the pollutant loading from older stormwater

management systems shall be reduced as necessary to restore or maintain the designated uses of waters.

2.1.5 Existing Requirements for Agriculture

Phosphorus and nitrogen in agricultural runoff come from application of fertilizer to crops and pastures, 

and animal wastes. A number of rules and programs address nutrient discharges from these sources.

FDEP Dairy Rule and CAFO Requirements

Chapter 62-670, F.S. requires all concentrated animal feeding operations (CAFOs) in the state of Florida 

that discharge water offsite to file an application for a NPDES permit with FDEP. It also prohibits 

discharge of process wastewater and runoff from any major egg production facility to surface waters 

except in the event of a 25-year, 24-hour storm event. In addition, dairy operations within the Lake 

Okeechobee Drainage Basin [as defined in 62-670.200(8)] and its tributaries are also required to 

implement BMPs for the purpose of reducing phosphorus inputs to the lake. Specifically, dairy farms in 

the Lake Okeechobee Drainage Basin must provide fencing to keep dairy cows away from surface water 

and have a system for waste collection, storage, and treatment, particularly in areas of high-intensity use. 

The rule also contains requirements for land application of waste, setback distance from surface water 

sources, and groundwater monitoring. The Dairy Rule does not establish a specific off-site phosphorus 

discharge concentration limitation, but rather requires BMPs to be incorporated into the operation of 

dairies. These BMPs need to provide reasonable assurances that each dairy could meet state water quality 

standards and that acceptable phosphorus levels in off-farm discharges would be achieved (Chapter 62-

670, F.A.C.). Although the Interim Lake Okeechobee SWIM Plan (SFWMD, 1989) established a 

maximum discharge limitation of 1.2 mg/L total phosphorus, the dairies are exempt from permitting and 
November 2010 2. Baseline for the Analysis 2-9 

enforcement under the Works of the District (WOD) Program3, since they are under the jurisdiction of the 

Dairy Rule.

The national CAFO rule, 40 CFR 122.23(d), requires CAFOs that have the potential to discharge be 

evaluated on a case-by-case assessment to determine whether the CAFO, due to its individual attributes, 

discharges or has potential to discharge. Discharges from the CAFO include discharges of manure, litter, 

or process wastewater from land application areas under the control of the CAFO. Agricultural 

stormwater discharges from CAFO areas (i.e., areas where animal waste has been applied in accordance 

with site specific nutrient management practices that ensure appropriate agricultural utilization of the

nutrients) are exempt. 

2.1.5.2 Agricultural BMP Manuals

In 1999, the Florida Watershed Restoration Act (FWRA) established BMPs as the primary instrument for 

implementing Florida’s TMDL program. Under the FWRA (Section 403.067, F.S.), implementation of 

BMPs that FDEP has verified as effective and FDACS has adopted by rule provides a presumption of 

compliance with state WQS. Participation in this program also provides a release from the provisions of 

Section 376.307(5), F.S. which requires that funds be paid for damages from the discharge of pollutants. 

As part of the manual development process, FDEP verifies the BMPs as effective at reducing pollutant 

loading to waters. Under the program, landowners maintain records and provide documentation regarding 

the implementation of BMPs utilized and reasons why certain BMPs are not applicable to their specific 

situation. The BMP manuals provide assessment tools to assist operators in determining the appropriate 

and applicable BMPs according to the type of farm and the basin where the farm is located. 

For example, the BMPs for cow/calf operations are divided into three levels. Level I BMPs are those that 

are largely applicable to all ranchers, and include nutrient management, alternative water sources for 

cattle, grazing management, general erosion and sediment control, water resource management, animal 

mortality disposal, conservation buffers and fences, integrated pest management (IPM), and wellhead, 

wetlands, and springs protection. Ranchers may have to implement Level II and III BMPs based on 

assessments identifying water quality risk features that require special attention or protection; these BMPs 

focus on high intensity areas, livestock use exclusion, and address the need for grade stabilization 

structures for sediment control and list situations that require comprehensive grazing management 

practices. 

For container nurseries, BMP practices include erosion control, fertilization management, irrigation 

management, pesticide management, nursery layout, waste management, and container substrate and 

planting practices. FDACS requests that nurseries assess current practices to identify which BMPs are 

already in practice and to identify any additional BMPs necessary. 

Sod growers must implement a minimum number of BMPs to establish a foundation for environmental 

protection. Depending on the farm’s site specific conditions or geographic location, the farmer could be 

exempt from implementing some of the minimum BMPs. As part of minimum BMP requirements farms 

must implement nutrient management, irrigation scheduling and maintenance, sediment and erosion 

control measures, integrated pest management, wellhead, wetlands and springs protection, ditch 

construction and maintenance, conservation buffers, stormwater management and mowing management. 

 

3 Each of the five water management districts in Florida has a WOD program. WOD represent canals, water control structures, 

rights-of-way, lakes and flowing waters and other water resources for which each district has responsibility or owns. 
November 2010 2. Baseline for the Analysis 2-10 

In addition, growers must also use the BMP decision-tree in the manual to identify other BMPs that are 

applicable to their farming operation. For example, growers who run seasonal sod farming operations may 

have fewer BMPs, while those farming in spring recharge basins or special regulatory areas may have 

additional BMPs that apply.

There are several citrus BMP manuals for different locations such as Gulf citrus, Indian and Peace River 

citrus, and Florida Ridge citrus. For citrus growers, the suggested BMPs include reducing the impact of 

pesticide use, reducing excessive nutrients, minimizing sediment transport and growth of aquatic plants, 

and reducing runoff flowing off-site. 

For vegetable and agronomic crops, farmers first must inventory current farm practices and then use the 

manual to identify additional BMPs applicable to their farming operation. These may include farm ponds, 

filter strips, flood protection, IPM, irrigation scheduling, maintenance and evaluation, fertilization 

management, riparian buffers, erosion control measures, wellhead and wetlands protection, access road 

mitigation, and ditch construction and maintenance. 

Under the FDACS program, farmers must submit a notice of intent (NOI) identifying the approved BMPs 

they intend to implement. Implementing the approved BMPs provides a presumption of compliance with 

state WQS and makes producers eligible for cost-share for certain BMPs. 

Lake Okeechobee Watershed Regulatory Program

There are several statutes and regulations governing the discharge of phosphorus in the Lake Okeechobee 

watershed.

Northern Everglades and Estuaries Protection Program 

The Northern Everglades and Estuaries Protection Program (formerly the Lake Okeechobee Protection 

Act; Section 373.4595, F.S.) is a phased watershed program to reduce phosphorus loads and implement 

long-term solutions to meet the TMDL for Lake Okeechobee and its tributaries. The initial phase of 

phosphorus load reductions is based on the District's Technical Publication 81-2 and WOD program, with 

subsequent phases of phosphorus load reductions based on the TMDLs (the TMDL boundary corresponds 

to the revised rule boundary). 

Under the statute, where FDACS adopts agricultural nonpoint source BMPs by rule, owners or operators

of agricultural nonpoint sources must either implement BMPs or demonstrate compliance with the South 

Florida Water Management District's (SFWMD) WOD program by conducting monitoring prescribed by 

the FDEP or SFWMD. For nonagricultural nonpoint sources, BMPs or interim measures adopted by 

FDEP or SFWMD must also be implemented. To verify the effectiveness of BMP implementation, 

SFWMD or FDEP is to monitor representative sites throughout the watershed. In cases where water 

quality problems persist despite the appropriate implementation of adopted BMPs, FDACS, SFWMD, or 

FDEP, in consultation with the other coordinating agencies and affected parties, can reevaluate the BMPs 

and make appropriate changes to the rule adopting BMPs.

Chapter 40E-61, F.A.C. 

SFWMD is responsible for implementing the SWIM Plan for Lake Okeechobee, establishing a program 

to protect the water quality of Lake Okeechobee and reducing the total phosphorus loading to Lake 

Okeechobee (to an average annual target load of 360 metric tons/year). Chapter 40E-61, F.A.C. addresses 

the reduction of phosphorus to Lake Okeechobee, and is based on the goals, objectives, and strategies 

contained in the SWIM Plan. According to 40E-61.041, each parcel of land within the Lake Okeechobee 

Watershed is presumed to connect to or make use of the WOD within the Lake Okeechobee Watershed, 
November 2010 2. Baseline for the Analysis 2-11 

and therefore, the rule requires them to obtain a general or individual permit, and to comply with 

applicable water quality performance limitations.

Chapter 40E-61 requires individual permits for parcels of land used for improved pasture (including 

heifer farms and dairies not covered by the FDEP Dairy Rule), vegetable farms (including row crops) and 

hog, poultry or goat farms located in certain sub-basins. Individual permit requirements include meeting 

interim annual average phosphorus limits (based on meeting the SWIM plan goal of 360 metric tons of 

phosphorus per year) and bi-weekly monitoring (performed by SFWMD until it determines compliance 

with the phosphorus limits). If the permittee exceeds the phosphorus limits, SFWMD may request that 

additional measures be taken to comply.

Parcels of land used for urban stormwater, nurseries, golf courses, land spreading of sludge, sugar cane, 

sod farms, or horse farms located in individual permit sub-basins must obtain a general permit under the 

current rule. General permit requirements include submitting an application or NOI with a statement 

indicating how phosphorus discharges will be controlled and meeting off-site phosphorus discharge 

concentration limits.

Landowners located in other sub-basins are also covered under a general permit, however, they do not 

have to submit an application/NOI assuming they do not exceed applicable phosphorus discharge limits 

(referred to as a No Notice General Permit). If monitoring data indicate that a discharger or sub-basin 

exceeds the limits, the landowner would be required to submit an application for a General or an 

Individual Permit, depending on land use. 

The current rule exempts the following entities from obtaining a permit regardless of phosphorus 

discharge levels:

 Dairy farms subject to and operated and maintained in compliance with the requirements of a 

valid permit issued pursuant to the FDEP dairy rule 

 Stationary installations regulated by the FDEP

 Activity on land units less than one-half acre in size which cannot reasonably be expected to 

discharge water in violation of the criteria in the rule

 Septic tanks, except for those that collectively create a local source of phosphorus that 

significantly impacts Lake Okeechobee as demonstrated by competent substantial evidence

 Activities exempt from permitting pursuant to Section 403.813(2), F.S., except when the District 

has a proprietary interest in the work.

Unless revoked or otherwise modified, the duration of an individual or general permit is three years from 

the date of issuance. SFWMD extends these permits automatically for another three year period, unless it 

notifies the permittee otherwise. Permits not automatically extended expire three years from the date of 

issuance unless an application for a renewal is filed. General permits remain effective until the rule is 

amended or the District notifies a permittee that the permit is revoked.

Chapter 40E-63, F.A.C. 

Chapter 40E-63 requires that any lands in the Everglades Agriculture Area (EAA) which release water 

that ultimately is discharged to the WOD (e.g., specifically named water control structures, rights-of-way, 

canals, and other water resources which the SFWMD owns) within the Everglades must have a general, 

individual, or master permit. The ultimate goal of the permits is to reduce total phosphorous loads 

discharged from the EAA by 25%. 
November 2010 2. Baseline for the Analysis 2-12 

A parcel of land qualifies for a general permit if it is a residential property less than 40 acres in size, not 

served by a central drainage system, or if it is commercial or industrial property less than 5 acres not 

served by a central drainage system. No NOI, permit application, or application fee is required for a 

general permit. 

Individual permits are required for all structures which discharge or release water to one of the WOD that 

do not qualify for a general or master permit. In the permit application, permittees must provide a 

description of BMP implementation and operation, including a description of rationale, consideration of 

BMPs provided in rule, a fertilization and water management plan for each crop, a monitoring plan to 

verify BMP effectiveness, an education and training program regarding BMPs, and a schedule for BMP 

plan implementation. Permittees must also provide a water quality monitoring plan which includes a 

description of monitoring program, and collection, sampling and testing method. 

Master permits are allowed for lands that are contiguous, have interconnected drainage systems, or 

proposed coordinated BMP plans. The requirements for a master permit are the same as those for an 

individual permit. In addition, permittees must provide information which demonstrates that the applicant 

entity or cooperating group of landowners possesses the legal, financial, and institutional authority and 

ability to carry out the terms of the permit.

Rule 5M-3, F.A.C. 

Under F.A.C. Rule 5M-3, the FDACS oversees implementation of BMPs for agricultural producers in the 

Lake Okeechobee watershed. The rule defines the phosphorus management requirements of agricultural 

producers necessary to receive a presumption of compliance with state water quality standards including 

those established under TMDLs. The following BMPs are approved for the Lake Okeechobee watershed:

 FDACS BMP manual for the Indian River Area citrus groves 

 FDACS BMP manual for cow/calf operations 

 FDACS BMP manual for vegetable and agronomic crops

 Site specific conservation plan, as defined in Rule 5M-3.002, F.A.C. 

 Site specific agricultural nutrient management plan (ANMP), as defined in Rule 5M-3.002, 

F.A.C., developed for a dairy or other concentrated animal feeding operation. 

However, farmer implementation of the BMP manuals provides a presumption of compliance with WQS

for those pollutants addressed by the practices. It also releases farmers from the provisions of Section 

376.307(5), F.S. which requires that funds be paid for damages from the discharge of pollutants.

Agricultural Assistance Programs

To encourage implementation of BMPs and various conservation measures, there are several national 

programs including: 

 Conservation Stewardship Program (CSP) – a voluntary conservation program that identifies and 

rewards through incentives those farmers and ranchers who meet the highest standards of 

conservation and environmental management on their operations 

 Conservation Reserve Enhancement Program (CREP) – program in which farmers receive 

payment to convert cropland and marginal pastureland to native grasses, trees, wetlands, and 

related conservation buffer practices to improve water quality, soil, and wildlife habitat
November 2010 2. Baseline for the Analysis 2-13 

 Conservation Technical Assistance (CTA) – program through which Natural Resource 

Conservation Service (NRCS) and its partners provide help to land users to address opportunities, 

concerns, and problems related to the use of natural resources and to help land users make sound 

natural resource management decisions on private, tribal, and other non-federal lands

 Environmental Quality Incentives Program (EQIP) – a voluntary conservation program for 

farmers and ranchers that offers financial and technical help to assist eligible participants install 

or implement structural and management practices on eligible agricultural land 

 Grazing Land Conservation Initiative (GLCI) – NRCS provides financial and technical assistance 

to landowners to support improved management of grazing land resources; successful in assisting 

landowners apply new technology to improve livestock production efficiency while maintaining 

or improving their natural resources.

2.1.6 Existing Requirements for Forestry

Florida’s Division of Forestry (FDOF) controls nonpoint forestry discharges of nutrients through the 

implementation of BMPs, as developed by the BMP Technical Advisory Committee and published in the 

Silviculture Best Management Practices Manual (FDOF, 2009). According to the manual, the BMPs

reflect “the minimum standards necessary for protecting and maintaining the State’s water quality as well 

as certain wildlife habitat values, during forestry activities,” and address many sources of pollution 

including sedimentation, nutrients, and turbidity. The manual contains 143 BMPs, within 14 categories 

organized by their application to different land types, waterbodies, activities, and special conditions. 

One of the BMPs included in the manual is the designation and management of Special Management 

Zones (SMZs), which are areas associated with particular waterbodies that are subject to specific criteria 

to protect the water from nutrient, debris, and other sources of pollution. Each waterbody type may have 

one or more applicable SMZ, including the primary zone (where some forestry activity may be allowed, 

but subject to stringent restrictions), the secondary zone (where forestry is not restricted but has some 

special requirements), and the stringer (which is a row of trees left at the bank to act as a barrier). 

The manual describes other BMPs according to the waterbody affected or the activity being performed in 

close proximity to it, and many pertain to the SMZs. The most relevant of these with regard to nutrient 

loading are those that relate to the application of fertilizer. For example, there can be no aerial application 

or transfer/loading stations in the primary zones (which are the most sensitive areas adjacent to 

waterbodies). There are also stated guidelines about how much fertilizer should be applied, and at what 

times, to minimize the potential for unintended migration of nutrients to the water, and stated maximum 

per-acre application rates.

Currently, BMPs are implemented primarily through educational outreach efforts such as workshops, 

demonstrations, and “master logger” certification classes offered through the Florida Forestry Association

(FDOF, 2010). FDOF periodically conducts state-wide surveys of silviculture practices to assess 

compliance levels, identify areas and foresters in need of further education, and evaluate the effectiveness 

of the BMPs. There have been 15 surveys since 1984, with the most recent in 2009. Over that period, the 

average compliance rate with all BMPs has been 94%, with 84% in 1985 and 98% compliance in 2009. 

The 2009 survey report also indicated that the implemented BMPs were generally effective at preventing 

significant impacts to the relevant waterbodies, although the report presented little data to support this 

conclusion (FDOF, 2010). 
November 2010 2. Baseline for the Analysis 2-14 

2.1.7 Existing Requirements for Septic Systems 

Nutrients from poorly maintained or failing septic systems or onsite sewage treatment and disposal 

systems (OSTDSs) can threaten both surface and groundwaters. In addition to runoff to surface water 

from mounded leach fields, nutrients can leach into groundwater beneath the system and be carried to 

nearby surface waters. 

In Florida, the Bureau of Onsite Sewage Programs in the Florida Department of Health (FDOH) and the 

environmental health section of County Health Departments regulate the use of OSTDSs. FDOH does not 

permit the use of an OSTDS where the estimated domestic sewage flow is over 10,000 gpd or the 

commercial sewage flow is over 5,000 gpd, where there is a likelihood that the system will receive toxic, 

hazardous or industrial wastes, where a sewer system is available, or if any system or flow is currently 

regulated by FDEP, unless a variance from these prohibitions has been granted by FDOH.

2.1.8 Existing Requirements for Air Sources 

Atmospheric deposition of nitrogen can be a significant source of nutrient loadings to lakes and flowing 

waters. However, the specific sources of atmospheric nitrogen are not typically well known and can 

originate from local, regional and international sources, including automobiles, power plants, volcanoes, 

and industrial air emissions. 

Florida Air Quality Regulations place an ambient air quality limit on nitrogen dioxide of 0.05 ppm 

(F.A.C. 62-204.240(5)). The major source of nitrogen dioxide is motor vehicle exhaust. Other sources 

include electricity generation, emissions from poultry litter, and other manufacturing processes. There are 

no other nitrogen- or phosphorus-based pollutants that have air quality standards in Florida, and 

atmospheric deposition is not considered to be a primary source of nutrient loading in the Southeastern 

United States (USGS, 2010). 

2.1.9 Legacy Sources 

Historic discharges of nutrients also provide current loadings in Florida waters. To the extent that legacy 

sources are identified and assigned load reductions in TMDLs, implementation plans identify control 

scenarios. In most cases, FDEP assumes that legacy sources will dissipate naturally, although this could 

take a long time. Consequently, BMAP controls may include temporary regional treatment systems. For 

example, in Lake Okeechobee, it may be necessary to integrate upland phosphorus control practices with 

regional treatment systems on the lower tributaries to meet the lake TMDL (SWET, 2008b). In time the 

accumulated phosphorus in these systems will wash out to establish a new equilibrium with the inflow 

phosphorus levels. Thus, the regional treatment systems would only be needed until the lakes and flowing 

waters come to equilibrium with the tributary loads. Jeppesen et al (2005; as cited in SWET 2008b) 

estimates that sloughs respond within 5 years to 20 years as compared to the larger lakes that could take 

much longer to establish a new equilibrium.

2.1.10 Summary and Assumptions

The current regulatory framework in Florida with respect to nutrients in lakes and flowing waters includes 

a narrative water quality criterion and procedures for identifying waters as exceeding the nutrient WQS. 

FDEP is addressing current impairments through requirements on a range of sources, established in 

BMAPs. In addition, regulations of specific sources (e.g., stormwater, certain agricultural producers) 

address nutrients and other pollutants in discharges, and require actions that will reduce nutrient pollution 

in lakes and flowing waters. 
November 2010 2. Baseline for the Analysis 2-15 

Because the cost of nutrient controls required by existing regulations (e.g., MS4 permit requirements, 

FDEP dairy rule) and BMAPs are expected without this rule, EPA included these costs in the baseline for 

this analysis. EPA also assumed that additional controls would not be needed for waters listed as impaired 

or covered under TMDLs for which FDEP has not completed a BMAP because nutrient reductions would 

be necessary in the absence of EPA’s rule. Thus, EPA did not include in this analysis costs associated 

with the following: 

 Actions necessary to meet existing NPDES permit conditions for municipal and industrial 

wastewater

 Control actions established in existing BMAPs

 Control actions needed to reduce nutrients in waters on the 303(d) list or covered under TMDLs 

 BMPs for the forestry sector

 Controls required by the FDEP Dairy Rule and EPA CAFO regulations 

 Requirements for the Lake Okeechobee watershed

 Phase I and Phase II MS4 Permits

 Requirements for urban areas developed after 1982 under Florida’s stormwater rule

 Urban Turf Fertilizer Rule. 

Given these requirements, EPA identified the level of new requirements that may be needed in each 

source sector to meet EPA’s numeric criteria. 

2.2 Existing Nutrient Discharges to Freshwater Lakes and Flowing waters

Sources of nutrient discharges to freshwater lakes and flowing waters include wastewater point sources 

(e.g., municipal wastewater treatment plants (WWTPs), industrial facilities), urban stormwater, 

agricultural runoff, septic systems, atmospheric deposition, and legacy sources.

2.2.1 Wastewater Point Sources 

EPA’s permit compliance system (PCS) database indicates that there are 198 municipal wastewater 

dischargers and 245 industrial dischargers with individual permits.4 Some of these permittees discharge to 

estuarine waters, coastal waters, or South Florida flowing waters and are not affected by the lakes and 

flowing waters rule. Also, not all industrial dischargers are likely to have the potential to discharge 

nutrients.

Given the nature of influent wastewater at municipal WWTPs, it is likely that all WWTPs have the 

potential to discharge nutrients. To identify industrial dischargers likely to discharge nutrients, EPA 

identified those dischargers in PCS with either numeric effluent limits and/or monitoring requirements for 

nitrogen and phosphorus (Exhibit 2-3). Based on these industrial categories, Exhibit 2-4 summarizes the 

number of NPDES-permitted wastewater dischargers in Florida that may be affected by the rule. Based on 

 

4 There are also 34,508 dischargers covered under generic or general permits. FDEP regulate these dischargers based on 

categories of wastewater facilities or activities that involve the same or similar types of operations or wastes. EPA did not include 

these dischargers in its analysis.
November 2010 2. Baseline for the Analysis 2-16 

FDEP (2010) analysis, EPA assumed that stormwater treatment areas and drinking water treatment plants 

would not be affected by the rule.5

 

Exhibit 2-3: NPDES Dischargers with Numeric Effluent Limits and Monitoring 

Requirements for Nitrogen and Phosphorus in Florida1 

SIC 

Code SIC Code Description

No. with Nutrient 

Effluent Limits1 

No. with Nutrient 

Monitoring Requirements1 

Majors2 Minors3 Majors2 Minors3 

0174 Citrus Fruits 1 0 1 0

1099 Miscellaneous Metal Ores, NEC 0 0 0 1

1422 Crushed and Broken Limestone 0 0 0 1

1475 Phosphate rock 14 1 15 5

1479 Chemical and fertilizer mineral mining, NEC 1 0 1 0

2015 Poultry slaughtering and processing 1 0 1 0

2033 Canned fruit and vegetables 1 1 1 1

2034 Dried and Dehydrated Fruits, Vegetables, 

and Soup Mixes 0 1 0 1 

2037 Frozen Fruits, Fruit Juices, and Vegetables 0 0 0 1

2082 Malt beverages 0 2 0 2

2085 Distilled and blended liquors 0 1 0 2

2491 Wood Preserving 0 0 0 2

2499 Wood Products, NEC 0 0 0 1

2611 Pulp Mills 2 3 0 0

2621 Paper Mills 0 0 1 0

2631 Paperboard Mills 0 0 2 0

2821 Plastics Materials, Synthetic Resins, and 

Nonvulcanizable Elastomers 0 0 1 0 

2824 Manmade Organic Fibers, Except Cellulosic 0 0 2 0

2869 Industrial Organic Chemicals, NEC 0 1 0 1

2873 Nitrogenous fertilizers 0 1 0 2

2874 Phosphatic fertilizers 12 16 1 1

2879 Pesticides and agricultural chemicals, NEC 1 0 1 0

2892 Explosives 1 0 1 0

3582 Commercial Laundry, Drycleaning, and 

Pressing Machines 0 0 0 1 

3679 Electronic Components, NEC 0 0 0 1

3699 Electrical machinery, equipment, and 

supplies, NEC 0 1 0 1 

3822

Automatic Controls for Regulating 

Residential and Commercial Environments 

and Appliances

0 0 0 6 

4011 Railroad haul line operating 0 2 0 2

4226 Special Warehousing and Storage, NEC 0 0 0 1

4911 Electric services 6 0 13 0

 

5 FDEP (2010) assumed that reject wastewater from drinking water facilities (SIC 4941) will be disposed by other means than 

surface water discharge and that stormwater treatment areas (SIC 3822) developed for Everglades restoration efforts within the 

Everglades Protection Area have separate criteria and are not included. 
November 2010 2. Baseline for the Analysis 2-17 

Exhibit 2-3: NPDES Dischargers with Numeric Effluent Limits and Monitoring 

Requirements for Nitrogen and Phosphorus in Florida1 

SIC 

Code SIC Code Description

No. with Nutrient 

Effluent Limits1 

No. with Nutrient 

Monitoring Requirements1 

Majors2 Minors3 Majors2 Minors3 

4931 Electric and Other Services Combined 0 0 0 1

4941 Water supply 0 8 0 20

4952 Wastewater treatment plants 78 0 46 53

4953 Refuse Systems 0 1 0 2

4959 Sanitary Services, NEC 1 0 1 0

5146 Fish and Seafoods 0 0 0 1

5169 Chemicals and Allied Products, NEC 0 0 0 1

5171 Petroleum Bulk stations and Terminals 0 0 0 1

5541 Gasoline Service Stations 0 0 0 1

7996 Amusement parks 0 4 0 6

8422 Arboreta and Botanical or Zoological 

Gardens 0 0 0 1 

8733 Noncommercial Research Organizations 0 0 0 1

9511 Air and Water Resource and Solid Waste 

Management 0 0 0 2 

9999 Nonclassifiable 0 1 0 0

Total 119 44 88 123

Source: U.S. EPA (2010a), accessed June 2010.

Major = generally discharge greater than 1 mgd and have the potential to discharge toxics in toxic amounts

Minor = generally discharge less than 1 mgd and do not discharge toxics in toxic amounts.

NEC = not elsewhere classified

SIC = Standard industrial classification

1. Including TN, ammonia, nitrate, and organic nitrogen, and TP .

Exhibit 2-4: Summary of NPDES Dischargers in Florida Potentially Affected by Numeric 

Nutrient Criteria for Lakes and Flowing Waters1

Discharger Category Major Dischargers Minor Dischargers Total

Municipal Wastewater 43 42 85

Industrial Wastewater2 57 51 108

Total 100 93 193

Source: U.S. EPA (2010a).

SIC = Standard Industrial Classification

TMDL = total maximum daily load

1. Excludes dischargers to oceans, estuaries, bayous, wetlands, and South Florida flowing waters (identified 

based on receiving waterbody name and information contained TMDLs, permits, and laboratory reports). 

2. For majors dischargers includes SIC codes 1475, 1479, 2015, 2611, 2621, 2631, 2821, 2824, 2874, 2879, 

2892, and 4911; for minor dischargers includes SIC codes 1099, 1422, 1475, 2033, 2034, 2037, 2082, 2085, 

2491, 2499, 2611, 2869, 2873, 2874, 3582, 3679, 3699, 3822, 4011, 4226, 4931, 4941, 4952, 4953, 5146, 5169, 

5171, 5541, 7996, 8422, 8733, 9511, and 9999. 

2.2.2 Stormwater

There are 27 Phase I MS4 permits and 133 Phase II MS4 permits in the state. Most of these entities have 

discharges to both fresh and marine waterbodies. Under existing permits, these entities implement 
November 2010 2. Baseline for the Analysis 2-18 

stormwater controls that target a number of pollutants including nutrients. Exhibit 2-5 shows stormwater

control projects conducted under TMDL Water Quality Restoration Grants in 2009 (FDEP, 2010a). 

Exhibit 2-5: MS4 Stormwater Control Projects in Florida

Entity Control Project 

Cost

Area 

Treated 

(acres)

TN 

Reduction 

(lbs/yr)

TP 

Reduction 

(lb/yr)

Titusville, City of Alum injection $1,655,169 114 1014.2 145.2

City of Palatka Baffle boxes $360,000 399 796.4 187

City of Ocala Dry retention +Wet pond 

(four phases) $2,536,248 738.27 3995.2 649

Lee County Offline filter marsh $2,194,520 7907 4191 220

Escambia County Wet detention pond $701,833 1375 470.8 473

Walton County Swales, wet detention pond, 

and 2nd generation baffle box $265,836 37 105.6 26.4

Maitland, City of Wet detention pond $2,586,301 120.8 237.6 228.8

Seminole County Wet detention pond $3,019,227 518.56 1606 147.4

Lake Worth Nutrient separating baffle 

boxes $1,000,000 280 2635.6 83.6

Lake County Water 

Authority Wet detention pond $1,628,699 27 501.6 77

Ocoee, City of Wet detention pond $2,600,000 124 413.6 63.8

Winter Park, City of Liquid/Solid separation

chamber $1,364,000 95 574.2 57.2

Port St Lucie, City of

Baffle boxes, stormwater

treatment area, sediment 

removal

$1,822,000 244 4083.2 1430

Martin County Wet detention, marshes, 

channel drainage improvement $2,902,518 107 286 90.2

Seminole County Wet detention pond $7,875,190 2801.61 1133 200.2

Deltona, City of Wet detention pond $2,227,448 430 481.8 167.2

Leesburg, City of Wet detention pond $1,429,000 132.4 380.6 132

Pinellas County Alum injection $2,990,533 920 2761 871.2

Lake County Dry retention pond $311,000 42 501.6 77

Jacksonville, City of Wet detention pond $4,384,800 1512 60585.8 545.6

Stuart, City of Wet detention pond, dredging $1,758,008 271 937.2 382.8

Marion County Dry retention pond $1,873,500 297 453.2 48.4

Rockledge, City of Wet detention pond expansion $931,500 685.5 4122.8 752.4

Gulfport, City of Dry retention pond $1,290,715 57.5 178.2 63.8

Port Orange, City of Wet detention pond, swales, 

plantings, $4,000,000 1720 827.2 272.8

Winter Garden, City of Wet detention pond with 

Alum treatment $3,075,127 549 2987.6 671

Sarasota, City of Wet Detention $16,873,000 3973.8 1507 723.8

Ocoee Public Work, 

City of

Wet Detention 

Ponds/Generation Baffle 

Boxes

$2,800,000 75 156.2 167.2

City of Titusville Wet Pond + Baffle Box $1,563,126 554.1 48.4 146.3

Tavares, City of NuRF Flow Data BMP'S 

Installed $7,400,000 119773 69040.4 10494
November 2010 2. Baseline for the Analysis 2-19 

Exhibit 2-5: MS4 Stormwater Control Projects in Florida

Entity Control Project 

Cost

Area 

Treated 

(acres)

TN 

Reduction 

(lbs/yr)

TP 

Reduction 

(lb/yr)

Martin County Office 

of Water Quality Wet detention ponds $6,825,000 540 1326.6 198

Martin County Office 

of Water Quality

Nutrient separating baffle 

boxes $788,000 169.29 167.2 83.6

Town of Surfside Drainage wells $1,747,000 131.8 1285.24 166.32

Atlantic Beach Wet pond $2,075,806 54.4 81.4 41.8

City of South Daytona Wet Detention/Littoral Zone $4,417,977 476 226.6 83.6

City of Maitland Exfiltration Trenches $1,098,365 20.3 37.4 8.14

Lake County Public 

Works Wet Detention Pond $2,340,000 125.5 596.2 107.8

SJRWMD Dry Retention/Wet Pond $3,000,000 8,343 33092.4 9504

Brevard County of 

Office Resources Wet Detention Pond $1,600,000 189 12.76 3.3

Lake County Wet Detention Pond $1,578,463 46.4 215.6 37.4

Source: FDEP (2010b).

2.2.3 Agriculture

The 2007 Census of Agriculture (USDA NASS, 2009) indicates that there are 47,463 farms and 9.2 

million acres of farmland in Florida. Three million of these acres are cropland, of which 1.6 million acres 

are irrigated. Livestock and poultry inventory includes 1.7 million cattle; 20,000 hogs and pigs; 11.8 

million layers; and 73 million broilers and other chickens. 

Farmers implement BMPs as part of the FDACS BMP program described in Section 2.1.5. Exhibit 2-6

shows the number of acres that farmers have enrolled in the FDACS BMP program. 

Exhibit 2-6: Summary of Agricultural Lands Enrolled in FDACS 

BMP Program

FDACS BMP Program Type Number of Acres

Citrus 509,553

Cow/Calf 448,602

Dairies 37,535

Equine 75

Grasses 3,271

Leatherleaf Ferns 144

Nursery 20,662

Poultry Feeding Operations 312

Row Crops 754,713

Sod Farms 33,813

Specialty Farms 306

Tri-County Agricultural Area 3,841

Total 1,812,827

Source: Based on GIS analysis of 2010 FDACS data on enrollments.
November 2010 2. Baseline for the Analysis 2-20 

The Florida Farm Bureau has documented a number of BMP successes throughout the state (FFB, 2010): 

 A watermelon farm achieved a farm-record yield using BMP irrigation and nutrient management 

tools; the amount of nitrogen used to grow the crop was 25% less than Institute of Food and 

Agricultural Sciences (IFAS)-recommended rates

 A strawberry farm was using three times the IFAS-recommended fertilizer rate (about 1.5 lb 

/acre/day) in order to fertilize plants because his irrigation practices led to leaching much of the 

applied nutrients; after implementing an evapotranspiration-based irrigation schedule and using 

BMP irrigation management tools, the farm’s fertilizer use is now below the IFAS-recommended 

rate (less than 0.5 lb/acre/day)

 A corn grower reduced nitrogen inputs by 30 lbs/acre on 70 acres using BMPs; this was a 

reduction of 2,100 lbs of nitrogen with no yield loss, and the grower has since reduced rates on all 

his fields

 A North Florida grower used soil moisture equipment for irrigation management as part of a 

BMP demonstration project; based on the soil moisture data, the grower modified his irrigation 

practices for perennial peanut, saving approximately 22.8 million gallons of water from one 

center pivot (reducing volume of water that runoffs off farm reduces the amount of nutrients to 

streams). 

However, farmers have submitted NOI to implement BMPs on less than 25% of all agricultural acres in 

the state, and attempts to verify implementation are limited. In the Suwannee River Basin and the Lake 

Okeechobee Watershed, dedicated staff from the Office of Agricultural Water Policy (OAWP) conduct 

site visits to ensure implementation, including follow-up visits to those farms deemed to be implementing 

BMPs unsatisfactorily (OAWP, 2009). As of October 2009, OAWP had visited 32 out of 40 enrolled 

dairies and 109 out of 119 enrolled poultry farms in the Suwannee River Basin, and about 21% of 

enrolled acres in the Lake Okeechobee Watershed. 

Due to limited resources, implementation assurance throughout the rest of the state has been primarily 

composed of mailed surveys to producers who submitted NOIs (with a response rate of about 64% for 

producers reporting citrus BMPs), as well as randomly selected site visit spot checks (OAWP, 2009). To 

date, OAWP has only done this for citrus producers, although OAWP has a schedule for implementing 

surveys and spot checks for producers enrolled in BMPs for vegetables/agronomic crops (Summer 2010), 

container nurseries (Fall 2010), sod (2011), cow/calf (2012), and equine and specialty fruit/nut (within 3-

4 years of manual adoption) (OAWP, 2009). 

2.2.4 Septic Systems

There are 935,203 septic systems in Florida, of which 793,697 are active (FDOH, 2010a). Most of 

Florida’s septic systems are over 30 years old and were installed under standards less stringent than 

current standards. In the 2008 Clean Watershed Needs Survey (U.S. EPA, 2010b), the state identified 

approximately $10.3 billion in capital need for decentralized wastewater treatment to address a water 

quality or a water quality-related public health problem existing as of January 1, 2008, or expected to 

occur within the next 20 years. These costs represent capital expenditures associated with the 

rehabilitation and replacement of septic systems and clustered (community) systems. For example, the 

LSJR TMDL Executive Committee (2008) indicates that the City of Jacksonville is implementing a 

phase-out of its septic systems by 2023. The phase out plan will address nutrients in addition to fecal 

coliform bacteria. 
November 2010 2. Baseline for the Analysis 2-21 

The relative source contribution to nutrient impairments from septic systems is often unknown or highly 

uncertain and current TMDLs use a wide variety of approaches to estimate it. For example, Petrus (2003) 

notes that in Lake County, there are about 63,000 septic systems leaking 8.59 mgd of nutrient-rich 

discharge (assuming 135 gallons per day per tank and a 1% failure rate, based on the number of repairs 

divided by the number of installed systems). TMDLs for Alachua, Newnans, and Orange Lakes use the 

methods described by the Watershed Management Model (WMM) which assumes that failing septic 

system effluent increases TN concentrations to waterbodies by up to 30 mg/L and TP loading by up to 4 

mg/L (the high end of the approximate range was used in all cases) and that 5% of septic systems are 

failing at any given time (Gao and Gilbert, 2003a; Gao and Gilbert, 2003b; Gao et al., 2006). Thus 

approximate nutrient loads from septic systems range from 2-5% for TN and 3-8% for TP (percentage is 

of the total existing nutrient load). 

The Juniper Creek TMDL assumes a higher concentration of these nutrients in untreated septic system 

effluent (50.5 mg/L for TN and 9.0 mg/L for TP; Wieckowicz et al. 2008). The authors also calculate the 

failure rate for Gadsden County using the number of septic tanks and the number of repair permits in a 

given period of time. Baniukiewicz and Gilbert (2004) also use a different approach in their development 

of a TMDL for Lake Hunter, basing their analysis on Haith et al. (1992) which calculates TN loading 

based on nutrients per person per day (12 g), plant nutrient uptake rates (1.6 g/d), the number of 

households with septic systems, and failure rate. Unlike for the other TMDLs in which researchers 

assume that failing septic systems represent a potential source of phosphorus loading, this approach 

reflects the assumption that phosphorus is adsorbed and retained by the soil and does not reach surface 

waters. 

Because of the uncertainty and inconsistency of current septic system nutrient loading estimates in many 

impaired waters, implementation plans primarily focus on septic system studies and research to better 

characterize nutrient loads and contributions. For example, preliminary data indicate that septic systems 

account for a relatively small percentage of the nutrient load in the Upper Ocklawaha River. Accordingly, 

the BMAP does not directly address septic systems during the first five years of implementation. 

However, FDEP acknowledges that the relative importance of loadings from septic tanks will increase 

after implementation of the management actions for other more significant sources (UOBWG, 2007). 

2.2.5 Atmospheric Deposition

Atmospheric deposition of nutrients from fossil fuel combustion, open pit mining, wind erosion, and other 

activities can represent a substantial source of nutrient loading to Florida’s waterbodies (Grimshaw and 

Dolske, 2002; Paerl et al. 2002). In current TMDLs, FDEP calculates deposition rates primarily by using 

published values for TN and TP rainfall concentrations throughout Florida (then multiplying by the 

precipitation volume and the surface area of the waterbody). In the nutrient budget for Lake Apopka, 

Stites et al. (2001; Gao, et al., 2006; Gao and Gilbert, 2003a; Gao and Gilbert, 2003b) found average TN 

and TP concentrations of 0.1 mg/L and 0.05 mg/L, respectively in rainwater; FDEP used these 

concentrations to calculate atmospheric nutrient loading for Alachua, Newnans, Orange, and Trout Lakes 

(Gao et al. 2006; Gao and Gilbert 2003a; Gao and Gilbert 2003b). 

Ahn and James (1999, as cited in Gao, 2006) found average concentrations of 0.630 mg/L for TN and 

0.05 mg/L for TP in agricultural areas. Because the area surrounding Lake Jesup has similar land uses, 

FDEP used these concentrations in atmospheric nutrient deposition modeling for its TMDL development 

(Gao, 2006). In developing a TMDL for Lake Hunter, regulators used rainfall samples collected from the 

nearby Winter Haven Chain of Lakes to estimate nutrient loading. Compared with the published values 

used for other TMDLs, they found similar concentrations of TN (0.680 mg/L) but lower concentrations of 
November 2010 2. Baseline for the Analysis 2-22 

TP (0.026 mg/L) (Baniukiewicz and Gilbert, 2004). Given the various deposition concentrations 

throughout Florida, it is uncertain whether such sources would be significant contributors to impairments. 

2.2.6 Legacy Sources

Some controls are in place to address legacy sources of nutrients. For example, in Lake Apopka in 

Florida, the sedimentary store of available phosphorus and the moderate hydraulic detention time (2.5 

years) resulted in a slow recovery (SJRWMD, 2003). To hasten reduction efforts, the St. Johns River 

Water Management District (SJRWMD) constructed a wetland system adjacent to the waterbody to 

remove phosphorus from lake water and permanently bury it in marsh sediments. Algae, resuspended 

sediments, and particle-bound nutrients are removed from lake water and sent through 13 independent 

marsh cells where phosphorus is removed (buried in marsh sediments). The phosphorus-reduced water 

then flows back to the lake (SJRWMD, 2003). 

The measured loads from for a particular watershed may not be fully representative of the potential 

nutrient load to the watershed. For example, in Lake Okeechobee, reducing upstream sources of 

phosphorus may not produce immediate results in downstream systems that have assimilated phosphorus 

for years because these systems may begin to release native or legacy accumulated phosphorus to come 

into equilibrium. 

2.2.7 Summary and Assumptions

Municipal WWTPs and industrial wastewater dischargers in certain sectors have a reasonable potential to 

discharge nutrients at levels that may contribute to the exceedance of EPA’s numeric nutrient criteria. 

Nonpoint sources, including urbanized and developed land, agricultural land, and septic systems are also 

possible sources of nutrients. Due to the extent of implementation of BMPs in forestry however, EPA 

assumed that loads from forest land are not likely to be substantial. Thus, this analysis is based on the 

following assumptions: 

 All municipal wastewater dischargers are potentially affected by the rule (a total of 84 

dischargers)

 Industrial dischargers in sectors that include dischargers with current effluent limits or monitoring 

requirements for nutrients are potentially affected by the rule (a total of 108 dischargers)

 Urban and agricultural land and septic systems may need controls for waters to attain standards.

EPA conducted more detailed analyses of municipal and industrial dischargers (presented in Sections 4 

and 5) to determine the potential need for additional nutrient controls by these dischargers above and 

beyond existing permit requirements (as noted in Section 2.1.3). In sections 2.1.4, 2.1.5, and 2.1.7, EPA 

similarly identifies the possible additional nutrient controls that may be needed above and beyond existing 

requirements for urban sources, agricultural sources, and septic systems, respectively. Although 

atmospheric deposition and legacy loads (e.g., sediments) may contribute measurable amounts of 

nutrients to some waters, what little data are available suggest that overall they are a relatively minor 

source. 

2.3 Current Water Quality

FDEP has previously determined that several waterbodies exceed the existing narrative nutrient WQS. 

These waters are identified on the state’s CWA Section 303(d) list. 
November 2010 2. Baseline for the Analysis 2-23 

2.3.1 Category 5 Waters on State 303(d) List

Exhibit 2-7 shows the number of waterbody segments or count of waterbody identification (WBIDs) 

labels listed as impaired for nutrients and/or dissolved oxygen (DO). TMDLs for DO impairments 

typically limit TN and/or TP concentrations as a means of achieving the DO targets, although DO

impairments could also be due to excessive biological oxygen demand or other sources not related to 

excess TN or TP. Category 5 waters are those impaired waters for which a TMDL is needed but has not 

yet been completed. Thus, the list in Exhibit 2-7 does not include WBIDs for which FDEP or EPA has 

developed a draft or final TMDL (see Section 2.3.2 for list of TMDLs). The exhibit also shows 

impairments to estuaries that are not subject to this rule because controls are often needed on upstream 

lakes and streams to achieve necessary reductions in the impaired waterbody. 

Exhibit 2-7: Summary of CWA Section 303(d) Listed Impairments for Nutrients in 

Florida1

Impairment Listing Number of WBIDs1 

Lake Stream2 Spring Estuary3 Total

Nutrients4 130 77 8 38 253

DO 12 110 3 23 148

Both (Nutrients and DO) 11 57 2 26 96

Total 153 244 13 87 497

Source: FDEP (2009d)

TSI = trophic state index

WBID = waterbody identification

1. Does not include those waterbodies for which a TMDL has already been approved.

2. Includes flowing waters and blackwater.

3. Includes estuaries, coastal waterbodies, and beaches.

4. Specific nutrient-related pollutants in the 303(d) list include TSI, chlorophyll-a, algae, algal mats, 

macrophytes, and other information.

2.3.2 Nutrient TMDLs 

There are approximately 168 WBIDs covered under TMDLs in Florida, 117 of which are for lakes and 

flowing waters. Exhibit 2-8 summarizes the approved and draft TMDLs for nutrients for lakes, streams, 

and springs. In Florida, TMDL implementation plans are developed in BMAPs and not as part of the 

TMDL. Only about 25% of the WBIDs shown below have accompanying implementation plans for 

achieving the target reductions/loads (other WBIDs covered under BMAPs do not have load allocations 

under TMDLs). 

Exhibit 2-8: Summary of Nutrient-Related TMDLs for Lakes and Flowing Waters in Florida

TMDL/Waterbo

dy

TMDL 

Year WBIDs

Total Nitrogen Total Phosphorus

TMDL 

(lbs/yr)

Percent

Reduction

Target 

(mg/L)

TMDL 

(lbs/yr)

Percent

Reduction

Target 

(mg/L)

Alachua Sink: dry 2006 2720A 204,870 46% 1.48 21,804 46% 0.16

Alachua Sink: wet 2006 2720A 256,322 45% 1.34 27,157 70% 0.15

Alligator Lake 2008 3516A 42,595 28% 1.16 3,050 61% 0.07

Butcher Creek 2005 2322 3,617 22% - - - -

Crane Strand 

Drain 2005 3014 29,828 29% 0.69 - - - 

Elevenmile Creek 2007 489 - - 0.74 - - -
November 2010 2. Baseline for the Analysis 2-24 

Exhibit 2-8: Summary of Nutrient-Related TMDLs for Lakes and Flowing Waters in Florida

TMDL/Waterbo

dy

TMDL 

Year WBIDs

Total Nitrogen Total Phosphorus

TMDL 

(lbs/yr)

Percent

Reduction

Target 

(mg/L)

TMDL 

(lbs/yr)

Percent

Reduction

Target 

(mg/L)

Fenholloway 

River 2009 3473B 3,025,850 24% - 219,000 19% 

Fishing Creek 2005 2324 39,697 22% - - - -

Imperial River 2008 3258E 18,865 25% 0.74 - - -

Gordon River 

Extension 2008 3278K, 3259C 34,822 29% 0.74 - - - 

Hendry Creek 2008 3258B 55,283 32% 0.74 - - -

Juniper Creek 2008 682 296,728 18.18% 0.72 - - -

Lake Hunter 2004 1543 6,579 80% 0.871 489 80% 0.061

Lake Jesup 2006 2981, 2981A 545,203 50% 1.27 41,888 34% 0.096

Newnans Lake 2003 2705B 85,470 74% 0.97 10,924 59% 0.062

Lake Harris 2003 2838A, 2338B - - - 18,302 32% 0.026

Lake Griffin 2003 2814A - - - 26,901 66% 0.032

Lake Eustis 2003 2817B, 2817A - - - 20,286 43% 0.025

Lake Dora 2003 2831B - - - 13,230 67% 0.031

Lake Carlton 2004 2837B - - - 195 59% 0.032

Lake Beauclair 2003 2834C - - - 7,056 85% 0.032

Lake Apopka 2003 2835D - - - 35,054 75.60% 0.055

Lake Okeechobee 2001

3212A, 3212B, 

3212C, 3212D, 

3212E, 3212F, 

3212G, 3212H, 

3212I

- - - 308,647 0.04

Lake Trafford 2008 32559W 56,617 60% 1.09 3,348 77% 0.025

Lake Wauberg 

Outlet 2003 2741 2,062 51% 1.01 374 50% 0.056

Lake Yale 2003 2807A - - - 2,844 10% 0.02

Little Weikiva 

Canal 2008 3004 42,624 45% 1.02 - - - 

Long Branch 2005 3030 10,400 17% 0.87 1,480 30% 0.14

Lower St. Johns 

River: marine 2008

2213A, 2213B,

2213C, 2213D,

2213E, 2213F,

2213G, 2213H

1,376,855 - 5.4 - - - 

Lower St. Johns 

River: freshwater 2008

2213I, 2213J, 

2213K, 2213L, 

2213M

8,571,563 - - 500,325 - - 

Munson Slough 2008 807D - 8.35% 0.72 - 17.53% 0.15

Munson Lake 2008 807C 95,074 46% 0.6 5,439 82% 0.037

New River 2008 3506 - 13% 1.3 - 38% 0.13

New River 2008 3506B - 38% 1.3 - - -

Orange Lake 2003 2749A - - - 15,262 45% 0.031

Palatlakaha River 2003 2839 16,696 5.2% - 2,207 7.2% -

Peace River above 

Bowlegs Creek 2007 1623J 24,750 30% - - - - 
November 2010 2. Baseline for the Analysis 2-25 

Exhibit 2-8: Summary of Nutrient-Related TMDLs for Lakes and Flowing Waters in Florida

TMDL/Waterbo

dy

TMDL 

Year WBIDs

Total Nitrogen Total Phosphorus

TMDL 

(lbs/yr)

Percent

Reduction

Target 

(mg/L)

TMDL 

(lbs/yr)

Percent

Reduction

Target 

(mg/L)

Suwannee Basin 2008

3422, 3422J, 

3422L, 3422R, 

3422S, 3422T, 

3422U, 3422Z, 

3605A, 3605B, 

3605C

Nitrate 

TMDL - - - - - 

Thirty Mile Creek 2004 1639 - - 3.0 - - -

Trout Lake 2006 2819A 9,733 60% - 521 80% -

Upper Lake 

Lafayette 2003 756A 34,669 - 1.0 3,946 39% 0.12

St. John's River 

above Lake 

Poinsett

2006 2893L - - - 178,000 37% 0.09

Lake Hell n' 

Blazes 2006 2893Q - - - 88,000 52% 0.09

St. Johns River ab.

Sawgrass Lake 2006 2893X - - - 114,000 32% 0.09

South Prong 

Alafia River 2009 1653 339,279 0% - 254,890 50% - 

Spring Lake 2008 2987A 8,551 30% 0.959 1,810 65% 0.021

Lake Florida 2008 2998A 8,377 34% 0.699 571 69% 0.023

Lake Orienta 2008 2998C 6,092 42% 0.814 451 74% 0.022

Lake Adelaide 2008 2998E 3,003 40% 0.711 228 72% 0.027

Lake Lawne 2008 3004C 21,692 26% 1.107 2,005 49% 0.055

Silver Lake 2008 3004D 6,241 24% 0.575 370 70% 0.015

Bay Lake 2008 3004G 1,428 39% 1.108 109 66% 0.019

Wekiva River

(u/s) 2008 2956 - - - - 61% 0.065

Wekiva River

(d/s) 2008 2956A - - - - 57% 0.065

Little Wekiva 

River 2008 2987 - - - - 78% 0.065

Black Water Creek 2008 2929A - - - - 36% 0.065

Lake Cannon 2007 1521H - - - 315 54% -

Lake Howard 2007 1521F - - - 315 62.5% -

Lake Idylwild 2007 1521J - - - 141 43% -

Lake Jessie 2007 1521K - - - 309 50% -

Lake Lulu 2007 1521 - - - 185 55% -

Lake May 2007 1521E - - - 194 57.5% -

Lake Mirror 2007 1521G - - - 121 27.5% -

Lake Shipp 2007 1521D - - - 214 65% -

C-24 Canal 2006 3197 579,620 28% 1.2 48,180 75% 0.1

Lake Parker 2006 1497B 151,684 57.4% - 30,481 57.1% -

Lake Lena 2006 1501 17,602 41% - 681 41% -
November 2010 2. Baseline for the Analysis 2-26 

Exhibit 2-8: Summary of Nutrient-Related TMDLs for Lakes and Flowing Waters in Florida

TMDL/Waterbo

dy

TMDL 

Year WBIDs

Total Nitrogen Total Phosphorus

TMDL 

(lbs/yr)

Percent

Reduction

Target 

(mg/L)

TMDL 

(lbs/yr)

Percent

Reduction

Target 

(mg/L)

Lake HancockLower Saddle 

Creek

2006 1623L, 1623K 702,167 75.2% - 224,320 75.5% - 

Lake Bonny 2006 1497E 14,523 57.7% - 1,921 57.7% -

Banana Lake 

Canal 2006 1549A, 1549B 34,717 79.4% - 56,510 79.5% - 

Saint Joe's Creek 2008 1668A 43,286 60% - 12,985 0% -

Pinellas Park 

Ditch No. 5 2008 1668B 2,541 70% - 915 0% - 

West Clark Lake 2005 1971 7,611 59.3% 1.018 1,480 10.8% -

Little Charlie 

Creek 2009 1774 19,929 61% - 4,840 61% - 

Bear Branch 2009 1948 2,705 43% - 396 43% - 

Prairie Creek 2009 1962 231,709 23.7% - 55,486 23.69% - 

Myrtle Slough 2009 1995 74,233 24.3% - 17,721 24.38% -

Hawthorne Creek 2009 1997 185,622 29.6% - 44,333 29.61% -

North Prong 

Alligator Creek 2009 2071 3,672,778 27.2% - 878,350 27.23% - 

Little Lake 2003 2838B - - - 18,302 32% 0.026

Little Gully 2009 1039 - 11% 0.63 - 11% 0.056

Lake Harney 2009 2964A 3,355,570 - 1.18 241,026 - 0.07

St. Johns River 

d/s of Lake 

Harney and above 

Lake Jesup

2009 2964, 2893F 3,741,990 - 1.18 276,141 - 0.07

St. Johns River 

above Lake 

Monroe and Lake 

Munroe

2009 2893D, 2893E 4,171,255 - 1.18 315,512 - 0.07

St. Johns River 

above Wekiva 

River

2009 2893C 4,202,340 - 1.18 318,236 - 0.07

North Prong 

Alafia River 2009 1621E - - - - 90% 0.415

Smith Canal 2009 2962 - - - 3,900 - 0.1

TMDL = total maximum daily load

WBID = waterbody identification

 “-“ = value not specified or determined in TMDL

Exhibit 2-9 provides a map of the WBIDs that are either on the state’s CWA Section 303(d) list for 

nutrients or for which a nutrient-related TMDL has been proposed or approved. 
November 2010 2. Baseline for the Analysis 2-27 

Exhibit 2-9: Map of Baseline Impairments in Florida
November 2010 2. Baseline for the Analysis 2-28 

EPA overlaid the WBIDs with 10-digit hydrologic units (HUCs) and land use/land cover data to identify

land use surrounding the baseline impaired waters [i.e., waters on the state’s CWA Section 303(d) list for 

nutrients including those covered by a TMDL].

6 Land use provides indication of the types of sources that 

will need to be controlled to remove existing impairments. Exhibit 2-10 summarizes the acres of each 

land use category for these waters.

Exhibit 2-10: Summary of Land Use for Baseline Impairments

Land Use Category Total Acres

% of Total Baseline 

Impaired Acres

Wetlands 5,523,931 25%

Agriculture 5,073,898 23%

Forest 4,433,810 20%

Urban 3,354,217 15%

Water 1,493,478 7%

Other 1,248,117 6%

Industrial 410,659 2%

Transportation Corridors 255,684 1%

Communications and Utilities 112,851 <1%

Total 21,906,645 100.0%

2.3.3 Summary and Assumptions

FDEP has already listed numerous lakes and flowing waters for nutrient-related impairment under the 

existing narrative nutrient criteria, and developed TMDLs for many of these waters. Some of these 

TMDLs established TN and TP targets, and these targets are either higher or lower than the EPA numeric 

criteria. In estimating the incremental impacts associated with the rule, EPA made the following 

assumptions with respect to current water quality: 

 The costs and benefits of nutrient controls for point and nonpoint sources that are already 

required under existing nutrient-related TMDLs for lakes and flowing waters are not attributable 

to this rule.

 Development of TMDLs for lakes, flowing waters, and springs on the current 303(d) list for 

nutrient-related impairment and the costs and benefits of nutrient controls needed to attain future 

TMDL targets associated with these impaired waters are not attributable to this rule.

 FDEP will likely pursue approval of TN and TP targets established under existing TMDLs as site 

specific alternative criteria (SSAC) such that this rule will not result in incremental costs or 

benefits to waters under existing TMDLs. 

Using these assumptions, EPA identified waters that would be identified as impaired under the rule but 

are not currently on the 303(d) list or under a TMDL. EPA refers to these waters as potential incremental 

impairments. EPA then estimated the costs and benefits of the nutrient controls needed to meet EPA’s 

numeric nutrient criteria for urban areas, agricultural land, and septic systems in surrounding watersheds; 

controls for municipal and industrial wastewater dischargers are based on attaining WQBELs reflecting 

the numeric nutrient criteria. The analysis of incrementally impaired waters is presented in Section 6, and 

 

6 Based on 10-digit hydrologic units containing at least 10% of a WBID that is listed on the state’s CWA Section 303(d) list for 

nutrients or covered by a TMDL]. 
November 2010 2. Baseline for the Analysis 2-29 

the analyses of controls for the different source sectors in Sections 4, 5, 7, 8, and 9. Note that because 

point sources receive WQBELs in NPDES permits, point sources are potentially affected regardless of the 

impairment status of the receiving waters.
November 2010 3. Description of the Rule 3-1 

3. Description of the Rule

This section describes the rule establishing numeric nutrient criteria for lakes, streams, and springs in 

Florida, and discusses potential state implementation of these criteria in NPDES permits, CWA Section 

303(d) listing and TMDLs, and requirements for nonpoint sources.

3.1 Water Quality Criteria

EPA’s rule establishes numeric criteria for TN and TP for freshwater lakes and streams in Florida, and a 

nitrate-nitrite criterion for springs. Exhibit 3-1 shows the waterbodies affected by the rule (designated by 

WBID numbers). 

Exhibit 3-1: Summary of Florida Waters

Waterbody Type Number of WBIDs Miles of Water Acres of Water

Lake 1,310 32 1,454,542

Spring 126 176 -

Stream, Excluding South Florida Streams 3,794 20,983 167,076

Total 5,230 21,191 1,621,618

Source: FGDL (2009). 

WBID = waterbody identification

EPA derived nutrient criteria for lakes on the basis of water color and alkalinity. Nutrient criteria for 

flowing waters are based of five geographically distinct regions that exclude the South Florida Region. 

The criteria are not to be exceeded more than once in a three year period. Exhibit 3-2 summarizes EPA’s 

numeric nutrient criteria for Florida lakes and flowing waters. 

Exhibit 3-2: Numeric Nutrient Criteria for Lakes and Flowing Waters in Florida

Region/Type of Water Chlorophyll-a 

(mg/L)

TN Criteria 

(mg/L)

TP Criteria 

(mg/L)

Nitrate + Nitrite 

Criteria (mg/L)

Colored Lakes1 0.020 1.27 0.050 NA

Clear Lakes (high alkalinity)2 0.020 1.05 0.031 NA

Clear Lakes (low alkalinity)3 0.006 0.50 0.011 NA

Panhandle East Flowing Waters NA 1.03 0.18 NA

Panhandle West Flowing Waters NA 0.67 0.06 NA

North Central Flowing Waters NA 1.87 0.30 NA

West Central Flowing Waters NA 1.65 0.49 NA

Peninsula Flowing Waters NA 1.54 0.12 NA

Springs NA NA NA 0.35

Chl-a = chlorophyll-a

Pt-Co = platinum-cobalt

NA = not applicable

TN = total nitrogen

TP = total phosphorus

1. Long-term Color > 40 Pt-Co

2. Long-term Color ≤ 40 Pt-Co and Alkalinity > 20 mg/L CaCO3. 

3. Long-term Color ≤ 40 Pt-Co and Alkalinity ≤ 20 mg/L CaCO3. 
November 2010 3. Description of the Rule 3-2 

EPA’s rule allows modification of lake criteria for chlorophyll a, TN and/or TP where the baseline 

chlorophyll a criterion-magnitude as an annual geometric mean has never been exceeded and sufficient 

ambient monitoring data exist for chlorophyll a and TN and/or TP for at least the three immediately 

preceding years. Sufficient data include at least four measurements per year, with at least one 

measurement between May and September and one measurement between October and April each year. 

Modified criteria are calculated as the geometric mean of all annual geometric mean concentrations from 

at least the immediately preceding three years in a particular lake. When the TN and/or TP criteria are 

modified, the chlorophyll a criterion must also be modified to reflect the same period of record for which 

TN and/or TP criteria are evaluated. Modified TP and TN criteria may not exceed criteria applicable to 

streams to which a lake discharges.

Exhibit 3-3 shows the locations of lake WBIDs in Florida and their classification under EPA’s rule. Note 

that color data are not available for several lakes. Exhibit 3-4 shows the nutrient criteria regions for 

streams under the rule.
November 2010 3. Description of the Rule 3-3 

Exhibit 3-3: Lake Types in Florida
November 2010 3. Description of the Rule 3-4 

Exhibit 3-4: Numeric Nutrient Criteria Regions for Streams in Florida

To ensure the protection of downstream lakes, EPA’s rule also requires that the applicable criteria in 

streams that discharge into lakes must be the more stringent of the instream TN and TP stream criteria and 

either the concentration of TN and TP derived to be protective of the lake [from application of 

BATHTUB (USACE, 2010) or another scientifically defensible model] or the lake criteria values for TN 

and TP. The applicable criteria are annual geometric mean values that are not to be exceeded more than 

once in a three year period.

3.2 Potential Implementation

WQS include designated use of the waters, criteria to protect those uses, and antidegradation policy. As 

described in Section 2.1.1, Florida WQS currently contain narrative nutrient criteria to protect designated 

uses, and FDEP assesses use attainment based on TSI, chlorophyll-a concentration, and other information 

indicating an imbalance in flora or fauna due to nutrient enrichment. EPA’s rule contains numeric criteria 

to protect the use; thus, assessment of impairment will also be based on numeric TN and TP 

measurements. This section discusses the potential impact of the criteria for implementing WQS in 

Florida. 
November 2010 3. Description of the Rule 3-5 

3.2.1 Impaired Waters and TMDLs

With the establishment of numeric criteria for TN and TP for lakes and flowing waters, FDEP may place 

additional waters on the state’s existing 303(d) list as impaired for nutrients. FDEP will have to develop 

TMDLs for waters that it identifies as impaired. EPA assumes that FDEP will use existing procedures for

attaining TMDLs for newly impaired waters, which consist of developing a BMAP to implement the 

TMDLs. 

Waters that exceed the new EPA criteria may also be exceeding the current narrative criteria but may not 

yet be listed for impairment because FDEP has not completed the process of identifying, verifying, and 

listing waters. In these cases, the impact of EPA’s rule could be to identify impaired waters sooner rather 

than later due to having appropriate numeric criteria for the assessment process. Implementing controls 

sooner and preventing additional degradation may result in cost savings and make restoration of 

designated uses more feasible compared to allowing excessive nutrient pollution to continue or increase.7

3.2.2 Controls for Point and Nonpoint Sources

Numeric nutrient criteria provide a basis for WQBELs in NPDES permits. Thus, FDEP may reopen 

permits for municipal and industrial wastewater sources to add WQBELs, or include WQBELs upon 

permit reissuance. Municipal WWTPs are likely to have reasonable potential to exceed the criteria and 

thus receive WQBELs; industrial dischargers may or may not have reasonable potential depending on 

industrial sector. WQBELs for point sources may require nutrient concentrations in effluent equal to the 

criteria, or allow higher nutrient concentrations in effluent because of dilution by receiving waters (e.g., in 

unimpaired waters).

Note that for impaired waters, FDEP’s TMDL Protocol (FDEP 2006b)8 establishes an initial focus of 

control efforts on nonpoint sources because FDEP believes point sources are already highly regulated. As 

illustrated by the efforts underway to reduce nutrient loadings from agriculture in the Lake Okeechobee 

watershed, such efforts have taken the form of making voluntary BMP programs mandatory, and iterative, 

performance-based approaches to attaining target watershed loadings. 

Because criteria apply to entire waterbodies and not individual dischargers, TMDLs can be implemented 

in the most cost effective manner to attain the criteria. When controls are not cost effective and would 

result in substantial and widespread economic and social impacts, implementation may include temporary 

variances from WQS that require the highest level of control that would not result in such economic 

impacts. Use attainability analyses that lead to modification of the designated use may also be appropriate 

in certain circumstances. 

 

7 Social discounting would result in costs today worth more than costs incurred in the future. However, pollution prevention is 

also less costly than restoration (if full restoration is even possible), and so more costs may need to be incurred if controls are 

initiated later.

8 FDEP (2006b) presents example standard protocols and references that may be considered for use by practitioners for 

conducting TMDL analyses and preparing TMDLs. FDEP developed the protocol report as a modular tool and reference.
November 2010 4. Potential Costs for Municipal Wastewater Sources 4-1 

4. Potential Costs for Municipal Wastewater Sources

Municipal sources of wastewater to freshwater lakes and streams receive WQBELs in NPDES permits. 

This section describes how EPA identified the municipal wastewater dischargers with the potential to 

receive revised effluent limitations for TN and TP as a result of state implementation of EPA’s rule and 

the resulting potential pollution control costs. 

4.1 Data

EPA’s permit compliance system (PCS) database contains a list of municipal WWTPs with NPDES 

permits in Florida. Receiving waterbody name and information in permits, fact sheets, and laboratory 

reports indicate whether the WWTP discharges to a freshwater lake or stream. The applicable TN and TP 

criteria depend on the receiving waterbody type (e.g., clear/colored lake or stream) and the location of the 

waterbody (e.g., for streams, criteria vary based on nutrient region). Exhibit 4-1 summarizes the number 

of WWTPs discharging to each waterbody type and criteria region (if applicable) and the applicable TN 

and TP criteria.

Exhibit 4-1: Summary of Applicable Criteria for Municipal WWTP Discharging to 

Freshwater Lakes and Streams

Criteria Region/

Lake Type

TN Criterion 

(mg/L)

TP Criterion 

(mg/L)

Major 

Dischargers1 

Minor 

Dischargers1 

Total

Dischargers

Clear Lake 0.5 – 1.0 0.01 – 0.03 1 0 1

Colored Lake 1.23 0.05 1 2 3

North Central 1.87 0.30 2 1 3

Panhandle East 1.03 0.18 4 1 5

Panhandle West 0.67 0.06 6 3 9

Peninsula 1.54 0.12 20 27 47

West Central 1.65 0.49 9 8 17

Total NA NA 43 42 85

1. As designated in EPA’s PCS database. Major dischargers are generally greater than 1 mgd and have the 

potential to discharge toxic pollutants in toxic amounts; minor discharges are typically less than 1 mgd and 

not likely to discharge toxic pollutants in toxic amounts.

4.2 Method

This section describes how EPA estimated the potential controls for municipal WWTPs to meet effluent 

limits based on EPA’s numeric nutrient criteria. 

4.2.1 Reasonable Potential

NPDES permitting authorities determine the need for WQBELs for point sources based on analysis of 

reasonable potential to exceed the water quality criteria. EPA’s rule does not include implementation 

procedures for determining reasonable potential. However, FDEP generally follows the procedures in 

EPA’s Technical Support Document for Water Quality-Based Toxics Control (TSD) for other pollutants 

with numeric criteria. For example, for aquatic life criteria, the TSD recommends finding a permittee has 

reasonable potential if it cannot be demonstrated with a high confidence level that the upper bound of the 

lognormal distribution of effluent concentrations is below the criteria at specified low-flow conditions 

(U.S. EPA, 1991). 
November 2010 4. Potential Costs for Municipal Wastewater Sources 4-2 

Medium to highly concentrated untreated domestic wastewater typically contains 40 mg/L to 70 mg/L of 

TN and 7 mg/L to 12 mg/L of TP (Metcalf and Eddy, 2003). Effluent concentrations of TN and TP in 

treated domestic wastewater depend on the treatment used. For example, activated sludge with single 

stage nitrification results in typical TN concentrations of 20 mg/L to 30 mg/L and TP concentrations of 6 

mg/L to 10 mg/L (Metcalf and Eddy, 2003). For advanced nutrient removal, technologies are available to 

reliably attain an annual average of 3 mg/L for TN and 0.1 mg/L or less for TP. (U.S. EPA, 2008). 

Effluent concentrations of 3 mg/L for TN and 0.1 mg/L for TP are the target levels of treatment for this 

analysis. 

Site specific data such as instream nutrient concentrations and low flow conditions would be required to 

precisely determine reasonable potential for each facility. However, this information was not available for 

every potentially affected WWTP. Thus, on the basis that most WWTPs are likely to discharge nutrients 

at concentrations above applicable criteria, EPA assumed that all WWTPs would have reasonable 

potential under the rule. 

4.2.2 Water Quality Based Effluent Limits

Based on TSD procedures, dischargers with reasonable potential would receive WQBELs that would take 

into account dilution, if available. Because data on water low flow conditions and other site specific data

are not available for every discharger, EPA assumed for this analysis that dischargers would receive 

effluent limits equal to the numeric nutrient criteria (i.e., assumption of no dilution). Applying criteria 

end-of-pipe would also prevent a discharger from causing an additional impairment. Furthermore, EPA 

assumed that all WWTPs would receive WQBELs of approximately 3 mg/L for TN and 0.1 mg/L for TP, 

consistent with current cost-effective nutrient removal technology. 

4.2.3 Potential Compliance Options

Potential controls to reduce TN and TP in WWTP effluents include biological nutrient removal (BNR), 

chemical precipitation, and effluent reuse. The specific level of performance achieved through 

implementation of advanced wastewater treatment systems can vary based on factors such as influent 

water quality, climate, and operator experience. For example, EPA (2008a) reports WWTPs are achieving 

average TN values ranging from 3.5 mg/L to 1.3 mg/L and TP values ranging from 0.43 mg/L to 0.09 

mg/L with advanced nutrient removal technologies that target both nitrogen and phosphorus. 

EPA recognizes that all numeric nutrient criteria for TN and the TP criteria for all lakes and streams in the 

Panhandle West regions are below the 3 mg/L TN and 0.1 mg/L TP target performance levels. In these 

cases, EPA assumed that the discharger will either implement technology consistent with levels that attain 

an annual average of 3 mg/L for TN and 0.1 mg/L or less for TP and achieve performance at levels that 

meet the WQBEL, or cannot achieve the required performance level and pursue other means of 

complying with WQS such site specific criteria, variances, or use designation modifications. In rare cases, 

where none of these mechanisms are appropriate, the state may require alternative technology or more 

costly solutions. 

BNR 

BNR removes TN and TP from wastewater through the use of microorganisms under different 

environmental conditions in the treatment process (Metcalf and Eddy, 2003). There are a number of BNR 

process configurations available. Some BNR systems are designed to remove only TN or only TP, while 

others remove both. BNR configurations vary in their sequencing of environmental conditions (i.e., 
November 2010 4. Potential Costs for Municipal Wastewater Sources 4-3 

aerobic, anaerobic, or anoxic)9 and timing (Jeyanayagam, 2005). Common BNR system configurations 

include: 

 Modified Ludzack-Ettinger (MLE) Process – continuous-flow suspended-growth process with an 

initial anoxic stage followed by an aerobic stage; used to remove TN

 Anaerobic-Anoxic Oxidation (A2

/O) Process – MLE process preceded by an initial anaerobic 

stage; used to remove both TN and TP

 Step Feed Process – alternating anoxic and aerobic stages; however, influent flow is split to 

several feed locations and the recycle sludge stream is sent to the beginning of the process; used 

to remove TN 

 Bardenpho Process (Four-Stage) – continuous-flow suspended-growth process with alternating 

anoxic/aerobic/anoxic/aerobic stages; used to remove TN

 Modified Bardenpho Process – Bardenpho process with addition of an initial anaerobic zone; 

used to remove both TN and TP 

 Sequencing Batch Reactor (SBR) Process – suspended-growth batch process sequenced to 

simulate the four-stage process; used to remove TN (TP removal is inconsistent)

 Modified University of Cape Town (UCT) Process – A2

/O Process with a second anoxic stage 

where the internal nitrate recycle is returned; used to remove both TN and TP

 Oxidation Ditch – continuous-flow process using looped channels to create time sequenced 

anoxic, aerobic, and anaerobic zones; used to remove both TN and TP. 

Exhibit 4-2 provides a comparison of the TN and TP removal capabilities of common BNR 

configurations. Because the performance of each process is dependent on site specific conditions, this 

exhibit represents only a general comparison of treatment performance among different BNR 

configurations. 

Exhibit 4-2: Comparison of Common BNR Configurations

Process Nitrogen Removal Phosphorus Removal

MLE Good None

A2/O Good Good

Step Feed Moderate None

Four-Stage Bardenpho Excellent None

Modified (Five-Stage) Bardenpho Excellent Good

SBR Moderate Inconsistent

Modified UCT Good Excellent

Oxidation Ditch Excellent Good

Source: Jeyanayagam (2005).

A2/O = anaerobic-anoxic oxidation

BNR = biological nutrient removal

MLE = Modified Ludzack-Ettinger

SBR = Sequencing Batch Reactor

UCT = University of Cape Town

 

9 Anoxic is a condition in which oxygen is available only in the combined form (e.g., NO2- or NO3-). However, anaerobic is a 

condition in which neither free nor combined oxygen is available (WEF and ASCE/EWRI, 2006).
November 2010 4. Potential Costs for Municipal Wastewater Sources 4-4 

Most large treatment plants should be able to achieve at least 3 mg/L for TN and 0.1 mg/L for TP 

(Jeyanayagam, 2005; CBP, 2002). However, site specific conditions may allow some facilities to achieve 

concentrations lower than these levels. For example, the city of Clearwater, Florida, operates two fivestage Bardenpho WWTPs. The second anoxic zone in the process provides denitrification of the nitrates 

created in the aeration zone (U.S. EPA, 2008a). TP is removed biologically in the anaerobic zone, and 

alum is fed to the second anoxic zone (the fourth reaction basin) for the dual purpose of phosphorus 

polishing and meeting the state requirement of low-level trihalomethane levels in the reuse water (U.S. 

EPA, 2008a). In addition, a gravity sand filter is used to remove phosphorus tied to suspended solids in 

the final effluent. The annual average concentrations are 2.32 mg/L TN and 0.11 mg/L TP at the Marshall 

Street plant, and 2.04 mg/L TN and 0.20 mg/L TP at the Northeast plant. Both plants operate with high 

efficiency and low variability (U.S. EPA, 2008a). In addition, the Lee County, Fiesta Village WWTP 

employs oxidation ditches with methanol addition prior to denitrification filters to achieve an annual 

average TN concentration of 1.38 mg/L (U.S. EPA, 2008a). To achieve average effluent TP 

concentrations of 0.1 mg/L, the facility uses alum addition and the denitrification filters to remove 

particulate phosphorus (U.S. EPA, 2008a).

Chemical Precipitation

Chemical precipitation primarily uses aluminum and iron coagulants or lime to form chemical flocs with 

phosphorus. These flocs then settle out to remove phosphorus from the wastewater (Viessman and 

Hammer, 1998). Compared to biological removal of phosphorus, however, chemical processes have 

higher operating costs, produce more sludge, and result in added chemicals in sludge (Metcalf and Eddy, 

2003). When TP levels close to 0.1 mg/L are required, a combination of biological and chemical 

processes may be less costly than either process by itself. In addition, chemical precipitation can be 

coupled with filtration to achieve levels at or below 0.1 mg/L. For example, EPA (2008a) provides the 

following examples of WWTPs with low TP effluent concentrations:

 Lee County, Florida: Oxidation ditch with denitrification filter with alum, TP = 0.098 mg/L 

 Chelsea, Michigan: Chemical addition with flocculating clarifier, TP = 0.09 mg/L (full-year data)

 McMinnville, Oregon: Chemical addition with tertiary clarifier and filter, TP = 0.058 mg/L 

(seasonal, 6 months of data) 

 Pinery, Colorado: 5-Stage Bardenpho with chemical and filter, TP = 0.031 mg/L 

 Breckenridge, Colorado: Enhanced biological phosphorus removal with chemical addition and 

filter, TP = 0.01 mg/L (literature report) 

 Brighton, Michigan: Chemical addition with tertiary filter and infiltration basin, TP = 0.01 mg/L 

(full year data)

Effluent Reuse

Effluent reuse does not reduce the concentration of nutrients in the effluent. However, partial effluent 

reuse (e.g., a portion of the wastewater is discharged to the receiving water and a portion is used in reuse 

applications) can decrease the volume of nutrient-containing wastewater discharged, decreasing the total 

nutrient load to the receiving water sufficient to meet the WQS. If the waterbody has no assimilative 

capacity, only 100% effluent reuse (i.e., no discharge to the receiving water) would be allowable. 

Effluent water can be reused for several nonpotable purposes including agricultural and landscape 

irrigation, industrial uses, and groundwater recharge. Costs associated with reuse applications include 

conveyance systems and storage tanks for reuse water as well as additional treatment that may be needed 
November 2010 4. Potential Costs for Municipal Wastewater Sources 4-5 

to meet reuse standards (e.g., low bacteria and turbidity concentrations). FDEP has adopted reused water 

standards that ensure protection of human health, such as the APRICOT Act of 1994 that contains 

provisions for backup water discharges and groundwater injection. However, the feasibility of effluent 

reuse as a control option for reducing nutrient loads to receiving waters depends on demand for reuse 

water. 

Site Specific Alternative Criteria 

If the characteristics of a receiving water allow attainment of designated uses with nutrient concentrations 

higher than EPA’s numeric nutrient criteria, site specific alternative criteria (SSAC) may be developed 

that could result in less stringent effluent limitations. Because dischargers may be required to obtain

additional data to assess the appropriateness of SSAC, the extent to which dischargers use this mechanism 

to obtain regulatory relief is uncertain. However, there may be a greater likelihood of pursuing SSAC in 

cases where using data and scientific evaluations associated with previous TMDL development efforts 

can result in significant cost savings.

Variance

Section 120.542, F.S. indicates that FDEP is authorized to grant variances to requirements of their rules 

or to rules required by EPA with approval of the variance from EPA. Under Chapter 62-110.104, F.A.C. a 

discharger must demonstrate that any hardship asserted as a basis for the need to receive a specific

variance is peculiar to the affected property and not self-imposed, and that the grant of a variance will be 

consistent with the general intent and purpose of Chapter 403, F.S. (Environmental Control Chapter of 

Florida Statutes), as applicable. 

To demonstrate the need for a variance under these statutes and procedures, dischargers would likely 

prepare documentation of the conditions warranting the variance. For example, to evaluate the potential 

for control costs to cause economic and social hardship, dischargers are likely to follow EPA’s (1995) 

Interim Economic Guidance for Water Quality Standards Workbook which provides worksheets and 

instructions for public and private sector entities. Following EPA (1995), dischargers conduct a two-step 

analysis, first determining whether the control costs would have a substantial adverse financial impact 

and, if so, whether that impact would cause widespread adverse impacts on the surrounding community. 

4.2.4 Potentially Affected Sources

Completed TMDLs for lakes and flowing waters provide wasteload allocations (WLAs) for both TN and 

TP for 18 municipal WWTPs, for only TN for 7, and for only TP for 2. EPA assumed that FDEP would 

likely seek to adopt the current TMDL nutrient targets as SSAC because scientific analysis has 

determined that they represent the maximum allowable nutrient concentrations for these waters. Because 

these dischargers are currently required to meet allowable nutrient discharge requirements, EPA assumed 

that additional treatment would not be needed for dischargers under a nutrient-related TMDL.

In addition, EPA also identified 12 municipal WWTPs discharging to waters listed as impaired for 

nutrients and/or DO on Florida’s current 303(d) list. EPA assumed that in the absence of its rule, these 

dischargers would be given WLAs under a TMDL. Thus, costs to reduce nutrients at these WWTPs 

would be attributable to the existing impairment and not EPA’s rule. 

The FDEP’s Wastewater Facility Regulation (WAFR) database and electronically available permits 

indicate that there are several WWTPs in Florida already operating treatment processes capable of 

achieving the targeted levels of 3 mg/L for TN and 0.1 mg/L for TP. For example, dischargers operating 

treatment processes that remove both TN and TP to the target levels of treatment (e.g., A2

/O, modified 

Bardenpho, modified UCT, oxidation ditches or other BNR coupled with chemical precipitation) would 
November 2010 4. Potential Costs for Municipal Wastewater Sources 4-6 

likely be in compliance with WQBELs based on numeric nutrient criteria. Dischargers operating 

treatment processes that remove only TN to levels consistent with performance of MLE and four-stage 

Bardenpho processes or TP to levels consistent with chemical precipitation without BNR would likely be 

in compliance with WQBELs based on numeric criteria for TN and TP, respectively. Municipal WWTPs 

without these configurations or those not operating BNR would likely need to retrofit or expand existing 

treatment to reduce nutrients to the necessary levels. 

Exhibit 4-3 summarizes the varying levels of treatment that could be required by municipal WWTPs 

under EPA’s rule on the basis of existing TMDL WLAs and effluent treatments. 

Exhibit 4-3: Potential Treatment Required for Municipal Wastewater Treatment Plants1

Discharge 

Category

Number of Dischargers

Reduce TN 

and TP1 

Reduce TN 

Only2 

Reduce TP 

Only3 

No 

Reductions4 Total

Major 11 2 9 21 43

Minor 19 1 3 19 42

Total 30 3 12 40 85

Source: Based on treatment train descriptions in FDEP (2009c) and permits and WLA in TMDLs, assuming 

dischargers would have to install advanced BNR for compliance under the rule. 

A2/O = anaerobic-anoxic oxidation

BNR = biological nutrient removal

MLE = Modified Ludzack-Ettinger

TMDL = total maximum daily load

TN = total nitrogen

TP = total phosphorus

UCT = University of Cape Town

WLA = wasteload allocation

1. 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. 

2. Includes dischargers with chemical precipitation only and those with WLA under a TMDL for TP only.

3. Includes dischargers with MLE, four-stage Bardenpho, and BNR specified to achieve less than 3 mg/L 

and those with WLA under a TMDL for TN only.

4. Includes dischargers with A2/O, modified Bardenpho, modified UCT, oxidation ditches, or other BNR 

coupled with chemical precipitation and those with WLAs under a TMDL for both TN and TP. 

4.2.5 Potential Control Costs

On the basis of the above estimates of potentially affected WWTPs and their current treatment processes, 

EPA estimated potential costs required for all municipal WWTPs to implement advanced BNR associated 

with EPA’s numeric nutrient criteria. EPA (2008a) provides unit cost estimates for BNR retrofits and 

expansions for various TN and TP performance levels. Exhibit 4-4 shows retrofit and expansion costs for 

estimates EPA (2008a) derived from wastewater treatment cost estimating software (CAPDETWorks).

Note that EPA excluded site specific estimated project costs from areas outside of Florida because costs 

for colder climate facilities (especially those in the Northeast) could be much greater than those for 

warmer climate facilities. Also, the costs for those facilities represent estimated design costs and not 

actual installed process costs. 
November 2010 4. Potential Costs for Municipal Wastewater Sources 4-7 

Exhibit 4-4: BNR Capital and O&M Unit Costs (2010 dollars)1

Source of Costs Flow 

(mgd) Description Capital Unit Cost ($/gpd)

O&M Unit 

Cost 

($/MG)

Annual Unit 

Cost 

($/gpd/yr)

TN Less than 3 mg/L

CAPDETWorks 10 Phased oxidation ditch retrofit $0.52 $49 $0.07

CAPDETWorks 10 MLE retrofit $0.79 $91 $0.11

CAPDETWorks 10 Step-feed retrofit $0.72 $101 $0.10

CAPDETWorks 10 Denitrification filter retrofit $0.79 $173 $0.14

Average $0.70 $103 $0.11

TP Less Than 0.1 mg/L

CAPDETWorks 10 Fermenter, sand filtration, and 1-

pt chemical addition retrofit $0.52 $118 $0.09

CAPDETWorks 10 2-pt chemical addition and filter 

retrofit $0.32 $238 $0.12

CAPDETWorks 10 2-pt chemical addition and filter

expansion $0.32 $238 $0.12

CAPDETWorks 10 A/O with fermenter, filter, and 

chemical addition expansion $1.72 $431 $0.32

Average $0.72 $256 $0.16

TN Less Than 3 mg/L and TP Less Than 0.1 mg/L

CAPDETWorks 10 PID retrofit with 1-pt chemical 

addition, clarifier, and filter $0.99 $221 $0.17

CAPDETWorks 10 5-stage Bardenpho and chemical 

addition retrofit $1.44 $284 $0.24

CAPDETWorks 10 Nitrification, chemical addition, 

and denitrification filter retrofit $0.83 $497 $0.26

CAPDETWorks 10

Nitrification with 1-point 

chemical addition and 

denitrification filter expansion $0.75 $448 $0.23

CAPDETWorks 10 5-stage Bardenpho, chemical 

addition, and filter expansion $2.48 $477 $0.41

Average $1.30 $385 $0.26

Source: U.S. EPA (2008a)

A/O = anaerobic/oxic

gpd = gallons per day

MG = million gallons

mgd = million gallons per day

mg/L = milligrams per liter

O&M = operation and maintenance

TN = total nitrogen

TP = total phosphorus

WWTP = wastewater treatment plant

1. Capital and O&M costs updated from original reported year dollars (May 2007 and July 2007) to June 

2010 dollars using the Engineering News Record Construction Cost Index (index values of 7942, 7959, and 

8566 for May 2007, July 2007, and June 2010, respectively).

The treatment level needed is based on the required pollutants reductions (Exhibit 4-3). Exhibit 4-5

summarizes the range of costs applicable to each type of discharger [the low end represents the average of 
November 2010 4. Potential Costs for Municipal Wastewater Sources 4-8 

unit costs and the high end represents costs for treatment processes that results in the highest annualized 

costs, based on annualizing capital at 7% over 20 years plus operation and maintenance (O&M) costs]. 

Exhibit 4-5: Treatment Level and Costs for Municipal Wastewater Treatment Plants

Reductions Needed Proposed Treatment Level Capital Cost 

($/gpd)1 

O&M Cost 

($/MG)1 

Both TN and TP TN <3 mg/L; TP <0.1 mg/L $1.30 - $2.48 $385 - $477

TP only TP <0.1 mg/L $0.72 - $1.72 $256 - $431

TN only TN <3 mg/L $0.70 - $0.79 $103 - $173

None None No costs No costs

mg/L = milligrams per liter

O&M = operation and maintenance

TN = total nitrogen

TP = total phosphorus

1. Low end represents average of unit costs; high end represents costs for treatment processes that results in 

the highest annualized costs, based on annualizing capital at 7% over 20 years plus O&M. 

Assuming the range of control costs shown in Exhibit 4-5 are indicative of those that similar facilities in 

Florida would incur to retrofit or expand existing treatment trains to implement advanced BNR, total 

capital costs could range between approximately $108 million to $219 million and annual O&M costs 

could range between approximately $12 million to $18 million. Total annual costs could range between

approximately $22 million to $38 million (annualized capital at 7% over 20 years plus annual O&M). 

These estimates reflect the unit costs multiplied by total flows contained in EPA’s PCS database, as 

shown in Appendix C. Note that the total does not include costs for three master reuse systems classified 

as municipal WWTPs in PCS. These systems receive inflow from several WWTPs which have or could 

need to install advanced BNR; thus, any discharges to surface waters from the master reuse systems 

should meet numeric nutrient criteria. 

Under the FDEP 2009 draft nutrient criteria baseline, annual incremental costs to municipal WWTPs 

could be zero because the treatment technologies needed to achieve the FDEP draft criteria are the same 

as those needed under EPA’s rule.
November 2010 5. Potential Costs for Industrial Wastewater Sources 5-1 

5. Potential Costs for Industrial Wastewater Sources

Industrial sources of wastewater to lakes and streams receive WQBELs in NPDES permits on the basis of 

their potential to discharge pollutants at levels that could cause or contribute to exceedance of a WQS. 

Unlike municipal WWTPs, however, not all industrial dischargers are likely to discharge nutrients

because industrial processes, treatments, and waste stream compositions vary widely. This section 

describes how EPA identified industrial wastewater with the potential to receive revised effluent 

limitations for TN and TP as a result of state implementation of EPA’s rule and the resulting potential

pollution control costs. 

5.1 Data

EPA’s PCS database provides information on numeric effluent limits and permit monitoring requirements 

for industrial dischargers in Florida (Exhibit 2-3). EPA assumed that any discharger (both major and 

minor) with a standard industrial classification (SIC) matching that of other dischargers with either a 

numeric effluent limit or monitoring requirement for nutrients has the potential to discharge nutrients. 

This analysis resulted in identification of 108 industrial dischargers that discharge to freshwater lakes and 

streams potentially affected by the rule. 

Completed nutrient and DO TMDLs for lakes and flowing waters indicate that 38 of the 108 potentially 

affected dischargers have WLAs for nutrients. As with municipal WWTPs, EPA assumed that FDEP 

would likely seek to adopt the current TMDL nutrient targets as SSAC because scientific analysis has 

determined that they represent the maximum allowable nutrient concentrations for these waters. Because 

these dischargers are currently required to meet allowable nutrient discharge requirements, EPA assumed 

that additional treatment would not be needed for dischargers under a nutrient-related TMDL. In addition, 

EPA also identified 14 industrial dischargers out of the 108 potentially affected facilities that discharge to 

waters listed as impaired for nutrients and/or DO on Florida’s current 303(d) list. EPA assumed that in the 

absence of its rule, these dischargers would be given WLAs under a TMDL. Thus, costs to reduce 

nutrients at these facilities would be attributable to the existing impairment and not EPA’s rule.

Exhibit 5-1 provides a summary of the number of dischargers of the remaining 56 possibly subject to 

WQBELs as a result of EPA’s criteria in each industrial sector that EPA identified as having the potential 

to discharge nutrients and incur incremental costs under the rule. 

Exhibit 5-1: Summary of Potentially Affected Industrial Dischargers

SIC Industrial Category Major 

Dischargers

Minor 

Dischargers

Total

Dischargers

1099 Mining - 2 2

1422 Mining - 4 4

1475 Mining 3 - 3

1479 Mining 1 - 1

2015 Food 1 - 1

2033 Food - 2 2

2037 Food - 1 1

2082 Food - 1 1

2085 Food - 1 1

2491 Pulp and Paper - 2 2

2499 Pulp and Paper - 1 1
November 2010 5. Potential Costs for Industrial Wastewater Sources 5-2 

Exhibit 5-1: Summary of Potentially Affected Industrial Dischargers

SIC Industrial Category Major 

Dischargers

Minor 

Dischargers

Total

Dischargers

2631 Pulp and Paper 1 - 1

2824 Chemicals and Allied Products 1 - 1

2869 Chemicals and Allied Products - 3 3

2874 Chemicals and Allied Products 2 1 3

2879 Chemicals and Allied Products 1 - 1

2892 Chemicals and Allied Products 1 - 1

3582 Other - 1 1

3679 Other - 1 1

3699 Other - 1 1

4011 Other - 2 2

4911 Electric Services 9 - 9

4931 Other - 2 2

4953 Other - 3 3

5146 Food - 1 1

5171 Other - 5 5

7996 Other - 1 1

8422 Other - 1 1

9511 Other - 1 1

Total -- 20 36 56

U.S. EPA (2010a).

5.2 Method

Treatment to reduce nutrient levels from industrial sources is facility-specific and varies on the basis of 

process operations, existing treatment train, and composition of waste streams. Thus, EPA evaluated the 

potential for control costs for a sample of dischargers and then applied these representative costs to all 

potentially affected dischargers. 

5.2.1 Sample Dischargers

EPA selected a random sample of dischargers not already covered under nutrient-related TMDLs 

stratified by industrial category. Exhibit 5-2 shows the number of sample dischargers selected compared 

to the total number in each industrial category. 

Exhibit 5-2: Summary of Industrial Sample by Category

Industrial Category Major Dischargers Minor Dischargers

Total Sample Total Sample

Chemicals and Allied Products 5 2 4 0

Electric Services 9 2 0 0

Food 1 1 6 1

Mining 4 1 6 1

Other 0 0 17 3

Pulp and Paper 1 1 3 0

Total 20 7 36 5

To estimate potential control costs, EPA first determined whether each sample discharger has reasonable 

potential to cause or contribute to an exceedance of the numeric TN and TP criteria using effluent data for 
November 2010 5. Potential Costs for Industrial Wastewater Sources 5-3 

discharge flows, TN, and TP from EPA’s PCS database and other information in the NPDES permits. For 

those with reasonable potential, EPA analyzed effluent data to determine compliance with potential

revised WQBELs for TN and TP (calculated based on available dilution, if any). If current data indicated 

that the facility would not be in compliance with the potential revised WQBEL, EPA determined the 

pollution controls most likely necessary for compliance and the cost of those controls. Appendix D

provides the detailed analysis for each sample discharger. 

5.2.2 Potential Compliance Options

Potential controls to reduce TN and TP in industrial effluents may include BNR, chemical precipitation 

with or without filtration, and source control. BNR, chemical precipitation, site specific criteria, and 

variances are discussed in Section 4.2.3. 

Source control targets reductions in pollutants at the source of entry into the wastewater system or within 

a specific treatment process rather than targeting reductions in total effluent. In most cases, it is more cost 

effective for industrial dischargers to control the source of nutrients in the effluent through BMPs, product 

substitution, process modifications, or process optimization than to treat the entire effluent prior to 

discharge. For example, in the Chesapeake Bay most industrial dischargers have reduced nutrient loads 

through pollution prevention (CBP, 2004). 

Source control can include a wide variety of activities. For example, to meet its WLA under the LSJR 

TMDL, Anheuser Busch improved pond nutrient removal with hyacinth management, a baffle system to 

improve retention time, and the use of aeration in some zones at its Lem Turner location. At its Main 

Street location, the discharger reduced the nutrient load by improving/modifying the site nutrient 

management plan and increasing the crop area to which they land applied a portion of the wastewater to 

reduce the nutrient load per acre (personal communication with T. Busby, Wildwood Consulting, August 

2009). Similarly as a result of the LSJR TMDL, Georgia Pacific reduced the amount of nutrients added to 

its treatment ponds (personal communication with T. Busby, Wildwood Consulting, August 2009). 

5.2.3 Potential Control Costs

To estimate total statewide costs, EPA calculated the average treatment unit cost in dollars per mgd of 

flow treated for each industrial category by dividing the total costs for the sample facilities in each 

industrial category by the total flow of the sample facilities in that group. EPA then multiplied the average

unit cost by the flow reported in PCS for each of the potentially affected facilities in the applicable 

category. For those facilities for which flow is not reported in PCS, EPA used the average flow of the 

other major or minor facilities in that industrial category (as shown in Appendix D). Exhibit 5-3 shows 

EPA’s estimate of potential statewide industrial discharger costs. 
November 2010 5. Potential Costs for Industrial Wastewater Sources 5-4 

Exhibit 5-3: Estimated Statewide Annual Industrial Control Costs

Industrial 

Category

Total Annual 

Sample Cost

($/yr)

Flow of Sample 

Dischargers

(mgd)

Average Unit

Cost

($/mgd/yr)1 

Total Flow of 

Affected 

Dischargers (mgd)2 

Total Annual 

Costs ($/yr)3 

Chemicals and 

Allied Products $206,800 14.7 $14,100 79.3 $1,116,800

Electric Services $0 133 $0 929 $0

Food $394,700 3.2 $123,300 11.3 $1,390,000

Mining $1,092,400 6.8 $160,600 102 $16,442,300

Other $0 1.2 $0 17.1 $0

Pulp and Paper $6,454,100 55 $117,300 55.1 $6,466,800

Total NA 214 NA 1,194 $25,415,900

Note: Detail may not add to total due to independent rounding.

NA = not applicable

1. Calculated by dividing total annual sample discharger costs by total sample discharger flow. Note that 

where flow for a sample discharger is not available, EPA used the average flow for dischargers in that 

category and discharger type (i.e., major or minor).

2. For the 34% of dischargers with no flows reported in PCS, EPA used the average flow for dischargers in 

the same category and discharger type (i.e., major or minor).

3. Represents average sample discharger unit cost multiplied by total flow of dischargers affected by the rule 

in each industrial category.

Under the FDEP 2009 draft nutrient criteria baseline, annual incremental costs to industrial dischargers 

could be zero because the treatment technologies needed to achieve the FDEP draft criteria are the same 

as those needed under EPA’s rule.
November 2010 6. Potential Impaired Waters 6-1 

6. Potential Incrementally Impaired Waters and Watersheds

To estimate the potential incremental impact of the rule on nonpoint sources, EPA first identified 

freshwater lakes, streams, and springs that may exceed the numeric nutrient criteria in the rule. Next, EPA 

identified land areas associated with these incrementally impaired waters to estimate the controls and 

costs that could be indirectly associated with attaining WQS. This section describes EPA’s analysis to 

identify potentially incrementally impaired waters and watersheds under the rule. 

6.1 Data

FDEP maintains a database of ambient water quality monitoring data for waters across the state and 

periodically updates this database under the impaired waters rule (IWR). The IWR database does not 

contain data for every WBID potentially affected under the rule because FDEP has not monitored all 

waters. However, the IWR database is the most extensive source of nutrient monitoring data available.

In 1996, FDEP redesigned its watershed monitoring approach, segregating water quality monitoring into 

three tiers:

 Tier 1 includes regular monitoring, using a probabilistic monitoring design to estimate water 

quality across the state on the basis of a representative subsample of waterbodies. 

 Tier 2 provides more intensive monitoring of waterbodies identified as impaired or at risk; FDEP 

implements it through strategic monitoring plans (SMPs) at the state water management district 

level. 

 Tier 3 monitoring is intensive monitoring for the development of TMDLs or the investigation of 

variances or site specific alternative criteria (SSAC).

Tier 1 is implemented through two mechanisms: the Status Network and the Trend Network. There are 52 

basins in Florida, divided into 5 districts. Through the Status Network, one basin from each district is 

assessed each year. FDEP established the ordering of these assessments on the basis of various priority 

factors such as whether the water includes surface water drinking sources, whether a TMDL must be 

developed for the water, or whether SWIM plans are underway. FDEP divides waterbodies into categories 

(large lakes, small lakes, large rivers, small rivers, confined aquifers, and unconfined aquifers) and 

randomly chooses a selection of each for monitoring. 

Surface water monitoring through the Trend Network consists of 75 fixed location sites in flowing waters 

that are sampled on a monthly basis. These sites enable FDEP to obtain chemistry, discharge, and loading 

data at the point where land use activities may have a large effect on the watershed. In addition, some 

sites are located at or near the Florida State boundary with Alabama and Georgia to obtain chemistry and 

loading data for major streams entering Florida. The sites are not designed to monitor point sources of 

pollution and are specifically located away from known outfalls or other regulated point source 

dischargers.

Special monitoring is also done on a subset of waterbodies that are identified as impaired or potentially 

impaired. After regular monitoring, FDEP identifies data gaps regarding these waterbodies and 

determines the number of samples for each parameter that are needed to allow assessment using the IWR 

process as described in Section 2.1.1. FDEP then prioritized these needs according to EPA’s categories 

for identifying monitoring needs:
November 2010 6. Potential Impaired Waters 6-2 

 Any WBID on the 1998 303(d) list of impaired waters. 

 Potentially impaired waters for which additional data are needed, including those identified by the 

IWR.

 Waters for which verified impaired threshold has been met, but monitoring must be maintained. 

 Waters for which data are insufficient.

 Waters for which there are no data.

FDEP tracks (but does not necessarily monitor) each waterbody it identifies as needing special monitoring 

every quarter to ensure sufficient data to conduct IWR assessment.

The IWR Run 40 database (made available May 2010) contains measurements of TN, TP, and/or 

chlorophyll-a from January 2005 through February 2010 for 877 lakes and 1,346 streams in Florida. It 

also contains nitrate-nitrite data for 72 springs for the same time period. 

6.2 Method

Compared to current conditions, potential incrementally impaired waters under the rule represent those 

waters that exceed EPA’s criteria that FDEP has not already developed a TMDL or listed as impaired for 

nutrients and DO (because TMDLs for DO often target nutrient reductions). [Appendix A provides an 

assessment of incremental impairments compared to numeric nutrient criteria representative of what could 

have been adopted in the absence of the rule (FDEP July 2009 draft numeric nutrient criteria baseline).] 

Using the last 5 years of data (2005-2010) from IWR Run 40, the method for identifying potential 

incrementally impaired lakes, streams, and springs entailed: 

 Identifying all state WBIDs

 Excluding WBIDs for which this rule is not applicable (e.g., estuaries, beaches, coastal 

waters, and streams in South Florida) 

 Excluding WBIDs for waters on the 303(d) list or for which there is a draft or approved 

nutrient-related TMDL (because EPA assumes controls to reduce nutrients already required 

in the absence of EPA’s rule would be sufficient)

 Excluding monitoring data flagged for quality concerns (e.g., result codes indicating QA/QC 

issues) 

 Identifying specifically applicable criteria for each WBID on the basis of waterbody type 

(lake, stream, spring), location (nutrient criteria region for streams), and color (assuming the 

more stringent clear lakes criteria apply if color is not available)

o Identifying WBIDs adjacent to lakes to which DPVs could apply (because DPVs 

will not apply to all waters intersecting lakes, including those flowing out of lakes;

Appendix B provides a sensitivity analysis of the impact of this conservative 

assumption on costs). 

 Calculating the annual geometric mean of TN, TP, and chlorophyll-a values and monthly 

geometric mean nitrite-nitrate concentrations, and comparing to the applicable criteria. 

EPA used FDEP’s 2009 draft data requirements for calculating annual geometric means and excluded 

data from years that did not contain at least four samples, with at least one in the summer season (May to 

September) and at least one in the winter season (October to April). This requirement ensures that 
November 2010 6. Potential Impaired Waters 6-3 

assessments represent seasonal variations in nutrient concentration. In comparison, monthly geometric 

mean values can be based on a single sample result. EPA assigned nondetects a value of one-half of the 

detection level in these calculations. This procedure ensures that waters with nutrient concentrations 

below the detection level are not erroneously categorized as not assessed due to insufficient data. For this 

analysis, EPA did not evaluate lake water quality monitoring data to determine the applicability of the 

lake criteria modification procedures specified in the rule. 

More than one annual geometric mean greater than the applicable numeric criterion for TN, TP, or 

chlorophyll-a in a three year period represents a potential impairment. For springs, any monthly geometric 

mean nitrate-nitrite concentration greater than the applicable criterion represents a potential impairment. 

FDEP’s assessment methodology specifies that waters with insufficient data are not to be listed as 

impaired. EPA followed this same methodology and did not consider waters with insufficient data as 

potentially impaired. 

6.3 Results

Exhibit 6-1 summarizes the potential incrementally impaired waters under the rule. 

Exhibit 6-1: Potential Incrementally Impaired Waters

Category Number of WBIDs Total Lake Stream1 Spring

Total in State 1,310 3,901 126 5,337

Not Listed/Covered by TMDL2 1,099 3,608 119 4,826

Nutrient Data in IWR Run 403 878 1,273 72 2,223

Sufficient Data Available4 655 930 72 1,657

Potentially Exceeding Criteria5 148 153 24 325

IWR = Impaired Waters Rule

TMDL = total maximum daily load

WBID = waterbody identification

1. Includes blackwater.

2. As reported in TMDL documents and FDEP (2009c).

3. Data within last 5 years meeting data quality requirements.

4. Annual geometric means based on at least 4 samples with one sample from May to September and one 

sample from October to April in a given year. For monthly geometric mean, there are no data requirements.

5. Based on annual geometric mean exceeding the applicable TN, TP, or chlorophyll-a criterion more than 

once in a three year period; for springs, based on more than one exceedance of the monthly nitrate-nitrite 

geometric mean criterion.

Note that some lake and stream WBIDs are impaired for TN, TP, and chlorophyll-a while others are only 

impaired for a single pollutant. For the purpose of estimating controls for nonpoint sources, EPA did not 

distinguish among the pollutants causing the impairment and assumed that controls to reduce TN, TP and 

chlorophyll-a are the same. Exhibit 6-2 shows the locations of incrementally impaired lakes and flowing 

waters in Florida.
November 2010 6. Potential Impaired Waters 6-4 

Exhibit 6-2: Map of Potential Incrementally Impaired Waters Affected by the Rule
November 2010 6. Potential Impaired Waters 6-5 

6.4 Land Use

Land use surrounding the potential incrementally impaired waters provides information on the types of

controls that may be needed to attain EPA’s criteria. EPA used 10-digit hydrologic unit codes (HUCs) to 

represent the watersheds for each impaired WBID. However, each WBID does not fall completely within 

a single 10-digit HUC. Thus, to ensure that lands (and sources) affecting water quality for each WBID are 

accounted for in the analysis, EPA identified watersheds containing at least 10% of an incrementally 

impaired lake or stream, excluding those watersheds that contain at least 10% of a lake or stream that is 

currently impaired or under a TMDL (to remove baseline impaired watersheds). EPA chose the 10% 

overlap factor to screen the incidental boundary mismatch type of overlap from real watershed overlaps.

Exhibit 6-3 summarizes the area of land in different use categories that surround potential incrementally 

impaired waters. 

Exhibit 6-3: Summary of Land Use for Potential Incrementally Impaired Watersheds

Land Use Category Total Acres Percent of Total

Forest 1,851,396 43%

Wetlands 1,171,382 27%

Agriculture 805,793 19%

Urban 263,499 6%

Water 83,790 2%

Other 48,765 1%

Industrial 31,951 1%

Transportation Corridors 18,544 <1%

Communications and Utilities 15,837 <1%

Total 4,290,958 100%

Note: Detail may not add to total due to independent rounding.

For springs, 10-digit HUC watersheds may not reflect the area influencing water quality. Rather, spring 

water quality is dominated by groundwater and surrounding aquifers which generally do not correspond 

to watershed boundaries. Spring recharge areas can be much larger than surface watersheds, and are much 

more complex, with great variability in distances that water travels to the outlet (USGS, 1999; 2010). 

Several factors tend to impede the precise delineation of spring recharge areas, often times making it 

difficult or impossible to distinguish a spring recharge area for a single outlet from a larger cluster of 

springs (Cohen, 2008; Upchurch, et al., 2008). For example, spring recharge area delineation is based on 

groundwater elevation, which is much flatter than the terrain used to delineate surface watersheds. Also, 

the boundaries of spring recharge areas can be dynamic, shifting based on rainfall patterns and recharge 

rates (USGS, 1999; Cohen, 2008). 

Florida spring recharge areas are especially difficult to delineate given the area’s karstic geology, which is 

characterized by sinkholes, cavities, siphons, conduits, uneven limestone topography, disappearing 

springs, and many other features that create a dynamic system of surface and groundwater flows (USGS, 

1999; Cohen, 2008). Some underground conduit systems can spread out for many kilometers (USGS, 

1999; 2010) and these (along with surface waters) can carry rainwater out of one spring recharge area into 

another in a distant location, often very rapidly (Cohen, 2008; Upchurch, 2008). Given these 

complexities, EPA determined potentially relevant nutrient sources for springs based on the individual 

source category rather than by utilizing 10-digit HUCs as in the case of surface waters.
November 2010 7. Potential Costs to Urban Stormwater 7-1

7. Potential Costs to Urban Stormwater Sources

State implementation of EPA’s numeric nutrient criteria may affect urban stormwater dischargers through 

changes to NPDES permit requirements, and the development of TMDLs and BMAPs. This section 

provides estimates of potential control actions and costs. These estimates are only approximate and for 

informational purposes only because actual control actions, if any, will depend on site specific conditions 

and control strategies. 

7.1 Data

As shown in Exhibit 6-3, urban land use (excluding industrial land, mine land, and inactive/undeveloped 

land) accounts for approximately 6% of the land use in the incrementally impaired watersheds. Under the 

baseline, a number of urban areas are already required to control nutrients in stormwater discharges 

through BMP implementation under MS4 NPDES permits. As described in Section 6.3, EPA identified 

potentially affected urban land by overlaying land use data with the 10-digit HUCs EPA determined to be 

near incrementally impaired waters. EPA further identified MS4 permit boundaries around this urban land 

by analyzing these data using GIS permit boundary data from the Florida Geographic Data Library 

(FGDL). Exhibit 7-1 summarizes EPA’s analysis identifying urban areas in incrementally impaired 

watersheds. Note this land use data may not be applicable to incrementally impaired springs.

Exhibit 7-1: Urban Land Area in Incrementally Impaired Watersheds

NPDES Permit Type Estimated Land Areas

Phase I MS4 61,800

Phase II MS4 93,000

No permit (Non-MS4) 112,000

Total 266,800

Note: Detail may not add to total due to independent rounding.

7.2 Method

The incremental controls that may be necessary based on state implementation of EPA’s numeric nutrient 

criteria will depend on existing permit requirements and regulations dictating BMP implementation, as 

well as the relative contribution of nutrients to impaired waters from urban runoff.

7.2.1 Controls for Lakes and Streams

This section describes how EPA estimated the potential cost of additional controls that may be required to 

meet EPA’s numeric nutrient criteria in incrementally impaired lakes and streams based on the baseline 

permit requirements noted in Section 2.1.4. 

Phase I MS4 Urban Land

Under existing regulations, NPDES permits for Phase I MS4s require implementation of BMPs to the 

maximum extent practicable (MEP) and do not generally require compliance with numeric effluent limits. 

For example, the Seminole County MS4 permit does not contain numeric effluent limits. In fact, EPA’s 

PCS database indicates that none of the Phase I MS4s in Florida have numeric effluent limits. While 

states have the authority to include numeric limits in MS4 permits, most rely solely on implementation of 

BMPs. The Seminole County MS4 permit indicates that each permittee must implement a comprehensive 

stormwater management plan that includes pollution prevention measures, treatment or removal 
November 2010 7. Potential Costs to Urban Stormwater 7-2

techniques, stormwater monitoring, and use of legal authority and other appropriate means to control the 

quality of stormwater discharged from the MS4. The Seminole County MS4 permit requires that any 

stormwater structural controls (e.g., controls that reduce volume and pollutants by the capture and reuse 

of stormwater, the infiltration of stormwater into porous surfaces, and the evaporation of stormwater) 

shall be operated in a manner to reduce the discharge of pollutants to the MEP. However, it is unclear 

what level of treatment the MEP represents. Thus, it is uncertain whether current stormwater pollution 

controls to the MEP are fully implemented in Phase I MS4 areas. 

Although urban runoff is currently regulated under the statutes and rules described above, EPA’s numeric 

nutrient criteria may result in changes to MS4 NPDES permit requirements or additional TMDLs and 

BMAPs that require additional pollution controls for urban runoff through state implementation. 

However, the combination of additional pollution controls necessary will likely depend on the specific 

nutrient reduction targets, the BMPs already in place, and the relative amounts of nutrients contained in 

the urban runoff at each particular location. As a result, stormwater programs usually use an iterative 

approach for assessing compliance that begins with implementation of BMPs followed by monitoring and 

re-evaluation. Estimating the complete set of pollution controls required to meet a particular water quality 

target would usually require site specific analysis. 

Although it is difficult to predict the complete set of potential additional urban runoff BMPs that may be 

needed to meet EPA’s numeric nutrient criteria, EPA estimated potential costs for additional treatment by 

assessing the amount of urban land in incrementally impaired watersheds on which additional pollution 

controls for stormwater could be implemented based on land use data from the FGDL using GIS analysis. 

FDEP’s existing stormwater rules already require at least an 80% reduction in pollutant loads from urban 

areas developed after 1982, and FDEP (2010b) indicated that stormwater runoff from this land should be 

in compliance with EPA’s numeric nutrient criteria. FDEP (2010b) also estimated that approximately 

78% of all urban land in the state was developed prior to 1982. Furthermore, nutrient reductions 

associated with previous completed nutrient-related TMDLs in Florida indicate that, on average, nonpoint 

source pollution load reductions of approximately 50% are necessary to meet TMDL targets for nutrients 

(range of 5% to 85%; see Exhibit 2-8). In the absence of site specific analysis, the type and location of 

pollution controls capable of achieving a 50% reduction are uncertain. However, urban stormwater

controls can remove up to 51% of TN and 75% of TP (Schueler, et al., 2007). Thus, EPA assumed that 

installation of stormwater pollution controls would result in the nutrient reductions necessary to attain 

EPA’s numeric nutrient criteria.

Using FDEP’s assumptions that all urban land developed after 1982 would not need to implement 

additional stormwater controls to comply with EPA’s numeric nutrient criteria, EPA estimated that 

between 0 acres (current controls to the MEP are sufficient) to 48,100 acres (61,800 acres of urban land in 

incrementally impaired watersheds × 78% of urban land developed before 1982) of Phase I MS4 urban 

land may require additional stormwater pollution controls. 

Phase II MS4 Urban Land

NPDES permits for Phase II MS4s require development of a stormwater management plan and 

implementation of BMPs based on six minimum control measures detailed in Section 2.1.4. For example, 

the Phase II Okaloosa MS4 stormwater management plan details BMPs the City plans to implement or 

that are already being implemented under each of the minimum control measures. Most of the BMPs in 

the stormwater management plan are nonstructural; thus, implementation of structural BMPs (e.g., baffle 

boxes, detention basins) may not be prevalent throughout Phase II MS4 areas. 
November 2010 7. Potential Costs to Urban Stormwater 7-3

GIS analysis of land use data from the state of Florida (as described in Section 7.1) indicates that 

approximately 58% of land in Phase II MS4 areas is low density residential (based on land use codes 

identifying low density residential land). The primary source of nutrients from low density residential 

land is from over-application of fertilizers on lawns and gardens. Thus, full implementation of the Urban 

Turf Fertilizer Rule should result in further reductions in nutrient loadings to surface waters (existing 

ambient monitoring data may not yet fully reflect nutrient reductions because the rule has only been in 

effect since July 2009). Other BMPs that target quantity of stormwater runoff from low density residential 

land may not be as cost-effective as the Urban Turf Fertilizer Rule which reduces the source of nutrients

in stormwater runoff. 

For the urban land that is not low density residential (42% in Phase II MS4s), some additional structural 

BMPs may be necessary to comply with EPA’s numeric nutrient criteria (existing TMDLs indicate that 

needed reductions in nonpoint source pollutant loads range from 5% to 85%, with an average of 50%; see 

Exhibit 2-8). Because nutrient reductions from low density residential land under the existing Urban Turf 

Fertilizer Rule are likely sufficient, and the state of Florida asserts that urban land developed after 1982 is

already in compliance with EPA’s numeric nutrient criteria, EPA estimated that approximately 30,700 

acres of Phase II MS4 urban land may require additional stormwater control [93,000 acres of Phase II 

MS4 land × (100% - 58%) of Phase II MS4 land not low density residential × 78% of urban land 

developed before 1982]. 

Urban Land Outside MS4s

Some urban land is not covered under EPA’s NPDES stormwater program. However, regulations such as 

the Urban Turf Fertilizer Rule are applicable, although existing ambient monitoring data may not yet 

reflect nutrient reductions related to this regulation because it has only be fully in effect since July 2009. 

GIS analysis of land use data from the state of Florida (as described in Section 7.1) indicate that 

approximately 65% of non-MS4 urban land is low density residential. The primary source of nutrients 

from low density residential land is the over-application of fertilizers on lawns and gardens. Thus, full 

implementation of the Urban Turf Fertilizer Rule should result in further reductions in nutrient loadings to 

surface waters. Other BMPs that target quantity of runoff from low density residential land may not be as 

cost-effective as the Urban Turf Fertilizer Rule which reduces the source of nutrients in stormwater

runoff. 

Because nutrient reductions from low density residential land under the existing Urban Turf Fertilizer 

Rule are likely sufficient, and the state of Florida asserts that urban land developed after 1982 are already 

in compliance with EPA’s numeric nutrient criteria, EPA estimated that approximately 30,600 acres of 

urban land outside of MS4 areas may possibly require additional stormwater controls to meet EPA’s 

numeric nutrient criteria [112,000 acres of non-MS4 land × (100% - 65%) of non MS4 land that is not 

low density residential × 78% of urban land developed before 1982]. Note that under TMDLs, FDEP may 

designate areas that are outside of MS4s and are significant contributors to pollutant loads as Phase II 

MS4s, and require those areas to obtain NPDES permits. 

Summary of Potentially Affected Area

Exhibit 7-2 summarizes the acres of urban land in the incrementally impaired watersheds for lakes and 

streams that could potentially need incremental controls based on the assumptions described above.
November 2010 7. Potential Costs to Urban Stormwater 7-4

Exhibit 7-2: Urban Land in Incrementally Impaired Watersheds Potentially Needing 

Controls

Land Type Estimated Acres in Incrementally 

Impaired Watersheds

Estimated Acres Potentially 

Needing Controls1 

MS4 Phase I Urban 61,800 0 – 48,100

MS4 Phase II Urban 93,000 30,700

Non-MS4 Urban 112,000 30,600

Total 266,800 61,300 – 109,400

Note: Detail may not add to total due to independent rounding

1. 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.

7.2.2 Controls for Impaired Springs

Reducing or eliminating land applications of nitrogen is the most cost-effective means of addressing 

potential nitrogen contributions from urban runoff in springs. The Urban Turf Fertilizer Rule is an 

example of one such source control effort. Other pollution prevention or source control activities include 

city or county-wide ordinances and public outreach and education campaigns for fertilizer BMP (both of 

which are already required in MS4 NPDES permits). Thus, EPA did not estimate costs for stormwater

controls for urban areas surrounding incrementally impaired springs, and assumed that implementation of 

existing (baseline) requirements would be sufficient for reducing nitrogen (including nitrate-nitrite) loads 

from urban runoff.

7.2.3 Potential Costs

Unit costs for stormwater treatment controls may vary based on the type of land needing controls (e.g., 

pervious versus impervious, high density versus low density). FDEP (2010a) provides unit costs in dollars 

per acre treated for completed stormwater retrofit projects throughout the state. Costs range from $62 per 

acre treated to $60,300 per acre treated depending on site specific characteristics, with a median cost of 

$6,800 per acre. Specific information regarding the characteristics of land potentially requiring controls is 

not available. Thus, EPA estimated control costs based on median unit costs from FDEP (2010a), with 

O&M costs equal to 5% of capital costs [consistent with FDEP (2010b) assumption of O&M equal to 5% 

of capital costs]. These estimates are shown in Exhibit 7-3. 

Exhibit 7-3: Estimated Incremental Urban Stormwater Cost Scenarios

Land Type Acres Needing 

Controls1 

Capital Cost

(millions $)2 

O&M Cost

(millions $)3 

Annual Cost

(millions $)4

MS4 Phase I Urban 0 – 48,100 $0 - $329.1 $0 - $16.4 $0 - $47.5

MS4 Phase II Urban 30,700 $210.0 $10.5 $30.3

Non-MS4 Urban 30,600 $208.8 $10.4 $30.2

Total 61,300 – 109,400 $418.8 - $747.9 $20.9 - $37.4 $60.5 - $108.0

1. See Exhibit 7-2. 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.

2. Represents acres needing controls multiplied by median unit costs of stormwater retrofit costs from 

FDEP (2010b).

3. Represents 5% of capital costs.

4. Capital costs annualized at 7% over 20 years plus annual O&M costs.
November 2010 7. Potential Costs to Urban Stormwater 7-5

Under the FDEP 2009 draft nutrient criteria baseline, annual incremental costs to urban stormwater could 

range from $13.7 million to $27.2 million, as described in Appendix A. 
November 2010 8. Potential Costs to Agricultural Sources 8-1

8. Potential Costs to Agricultural Sources

Agricultural dischargers in Florida do not generally receive discharge permits unless specific regulations 

require them (e.g., the South Florida Water Management District WOD program). However, state 

implementation of EPA’s numeric nutrient criteria may result in additional BMP requirements for these 

dischargers through the identification of additional nutrient-impaired waters and subsequent TMDLs and 

BMAPs. Existing nutrient TMDLs and BMAPs indicate that wastewater point sources may not be the 

primary source of nutrients to impaired waters. FDEP’s TMDL Protocol (2006b) asserts that most point 

source dischargers are already providing a high level of wastewater treatment and that initial control 

strategies may focus generally on stormwater and nonpoint sources. Thus, it is possible that controls on 

nonpoint sources such as agriculture may be needed to meet EPA’s numeric nutrient criteria.

This section describes provides estimates of agricultural land that may require additional nutrient controls 

as a result of state implementation of EPA’s rule and potential control costs. These estimates are only 

approximations for informational purposes; actual costs will depend on site specific conditions and 

control strategies. 

8.1 Data

As shown in Exhibit 6-3, EPA estimated that agricultural land accounts for approximately 19% of land 

near potential incrementally impaired waters (excluding land near existing baseline impaired waters).

Exhibit 8-1 shows the agricultural acreage near potential incrementally impaired waters subdivided into 

the specific type of agricultural operation that presently occurs there. 

Exhibit 8-1: Agricultural Land Use in Incrementally Impaired Watersheds

Agricultural Land Use Area (acres) % of Total Area

Animal Feeding 1,846 <1%

Citrus Crop 27,343 3%

Cow Calf Production, Improved Pastures 168,665 21%

Cow Calf Production, Rangeland and Wooded Pasture 51,057 6%

Cow Calf Production, Unimproved Pastures 75,790 9%

Cropland and Pasture Land (general) 160,814 20%

Dairies 621 <1%

Field Crop (Hayland) Production 215,168 27%

Horse Farms 1,632 <1%

Ornamental Nursery 840 <1%

Row Crop 9,808 1%

Sod/Turf Grass 2,007 <1%

Other 67,364 8%

Land not in production 22,839 3%

Total 805,793 100%

Source: Based on GIS analysis of land use data from five water management districts in Florida.

Note: Detail may not add to total due to independent rounding.
November 2010 8. Potential Costs to Agricultural Sources 8-2

8.2 Method

When developing nutrient TMDLs for impaired waters, site specific analysis is generally needed to 

determine the nutrient reductions required from agricultural nonpoint sources and to identify the 

appropriate agricultural BMPs capable of attaining the necessary reductions. For example, EPA’s 

Chesapeake Bay Program Office developed detailed watershed modeling of sources of nutrients and 

sediment affecting water quality in the Chesapeake Bay that it used to identify control scenarios for 

attaining water quality standards (U.S. EPA, 2003a). The reductions obtained from any one practice will 

vary with onsite conditions including soils and proximity to waters, BMP implementation, and nutrients 

used or produced. 

Because this type of analysis for incrementally impaired watersheds is beyond the scope of this analysis, 

EPA estimated the potential incremental costs of additional agricultural BMPs that may be necessary to 

meet EPA’s numeric nutrient criteria using a study of BMP requirements and costs performed by Soil and 

Water Engineering Technology, Inc. (SWET, 2008a) in the development of nutrient TMDLs for the 

Caloosahatchee River and St. Lucie River (SWET, 2008a). SWET (2008a) develops three types of BMP 

programs: the set of BMPs that land owners would likely implement without incentives (owner program); 

the set of BMPs that would be implemented under a reasonably funded cost share program or modest 

regulatory approach (typical program); and more aggressive and costly controls (alternative program) that 

could be needed if additional nutrient reductions are required. 

The BMPs in SWET’s (2008a) owner and typical programs are similar to the BMPs adopted in FDACS 

BMP manuals (Section 2.1.5) and those detailed in existing BMAPs [although it is uncertain whether the 

mix of BMPs farmers are implementing under the FDACS BMP manuals reflect the same level of control 

as the SWET (2008a) owner/typical program in all cases]. Exhibit 8-2 shows the BMP program 

components SWET (2008a) estimated would be appropriate for each type of agricultural activity.

Exhibit 8-2: Example Agricultural BMP Program Elements for the Caloosahatchee River 

and St. Lucie River Watersheds

Land Use Owner/Typical Program

Citrus Reduced fertilization/nutrient management, grass management between trees, 

additional stormwater retention, and limited wetland restoration/retention

Cow Calf, Improved 

Pastures

P reduced to zero/nutrient management, rotational grazing, new water facilities, 

retention basin by working pens, improved grass management, feed placement, 

critical area fencing, and moderate wetland restoration/retention

Cow Calf, Unimproved 

Pastures

Some rotational grazing, new water facilities, retention basin by working pens, 

improved grass management, feed placement, and moderate wetland 

restoration/retention

Cow Calf, Rangeland and 

Wooded Pasture 

Some rotational grazing, new water facilities, retention basin by working pens, 

improved grass management, feed placement, and moderate wetland 

restoration/retention

Dairies Stormwater R/D and wetland restoration feed management

Field Crop (Hayland) 

Production/Other Areas

P reduced to zero/nutrient management, rotational grazing, new water facilities, 

retention basin by working pens, improved grass management, feed placement, 

critical area fencing, and moderate wetland restoration/retention

Ornamental Nursery Reduced P fertilization, water management, additional stormwater retention, 

cover crop, and limited wetland restoration/retention

Row Crop Reduced P fertilization, water management, additional stormwater retention, 

cover crop, and limited wetland restoration/retention
November 2010 8. Potential Costs to Agricultural Sources 8-3

Exhibit 8-2: Example Agricultural BMP Program Elements for the Caloosahatchee River 

and St. Lucie River Watersheds

Land Use Owner/Typical Program

Sod/Turf Grass Reduced P fertilization, water management, additional stormwater retention, and 

limited wetland restoration

Horse Farms

P reduced to zero/nutrient management, rotational grazing, new water facilities, 

retention basin by working pens, improved grass management, feed placement, 

critical area fencing, and moderate wetland restoration/retention

R/D = retention/detention

Source: SWET (2008a).

SWET (2008a) estimates costs for an alternative program which it indicates may be necessary if 

additional nutrient reductions are needed beyond what the owner/typical program could obtain. However, 

these alternative practices, which include stormwater chemical treatment are not yet required in 

historically nutrient impaired watersheds with significant contributions from agriculture (e.g., Lake 

Okeechobee). Thus, it is highly uncertain whether such controls would ever be required. Therefore, for 

this analysis, EPA believes it is reasonable to assume that costs to the agricultural sector are best 

represented by the owner and typical BMP program unit costs described above. 

FDEP must verify that FDACS BMPs are reasonably expected to be effective [Section 403.067(7)(c)(3), 

F.S.]. However, it is unclear whether all necessary BMPs are implemented in all cases because individual 

agricultural operators apply the FDACS BMP manuals with little state oversight. Therefore, EPA 

estimated potential incremental costs by applying unit costs only to agricultural acres near incrementally 

impaired waters that are not currently enrolled in the FDACS BMP program (assuming that acreage 

currently enrolled in FDACS BMP program do not require additional BMPs) and by applying costs to all 

agricultural acres near incrementally impaired waters whether or not they are currently enrolled in the 

FDACS BMP program (assuming that acreage currently enrolled in FDACS BMP program may require 

additional BMPs, although such an estimate may double count some costs). 

Agricultural practices, particularly the application of mineral fertilizers, can be substantial contributors to 

nitrate loads in springs (USGS, 1999; 2010; Cohen, 2008). The risk of nutrient contamination to spring 

recharge areas is especially high where the aquifer underlying the surface application is unconfined and 

there is a high degree of hydraulic connectivity between the surface and the aquifer (Cohen, 2008; USGS, 

2010). Nitrate concentrations of over 100 mg/L have been observed just downgradient from row crops 

and dairy farms (Cohen, 2008), and groundwater nitrate concentrations are generally the highest in 

shallow wells below agricultural sources (USGS, 2010). 

Fertilizer application and other agricultural practices can significantly increase nitrate loadings to springs, 

especially those with relatively large source water aquifers (USGS, 2010). For example, over 2,000 

square miles of land provide the source of water to the portion of the Floridan Aquifer that discharges to

Wakulla Spring (and its neighboring springs) (Chelette, et al., 2002). In land areas most immediately 

draining to the spring (over 700 square miles in Wakulla and Leon Counties), at least 40,300 acres 

(16,300 hectares) of fertilized farmland overlie unconfined and semi-confined portions of the aquifer, 

contributing 25% of anthropogenic nitrate to Wakulla Spring (Chelette, et al., 2002). Thus, farms many 

miles away can significantly affect spring water quality. 

Because nutrient management is a cost-effective way to reduce groundwater nitrogen and may even result 

in cost savings to farmers by reducing unnecessary fertilizer application (see Section 2 for examples),
November 2010 8. Potential Costs to Agricultural Sources 8-4

EPA assumed that all agricultural operations applying fertilizer to land would implement a nutrient 

management program to reduce levels of nitrogen in groundwater aquifers. Nutrient management reduces 

over application of fertilizers by determining realistic yield expectations and the nutrient requirements 

necessary to obtain those yields, and adjusting application methods and timing to minimize nutrient 

pollution (USDA, 1998; U.S. EPA, 1993). Fertilization requirements vary by crop across the state 

(UF/IFAS, 2009). 

8.3 Potential Costs

This section describes how EPA estimated potential incremental costs to agricultural operations that may 

be required as a result of state implementation of EPA’s numeric nutrient criteria.

8.3.1 Lakes and Streams

Exhibit 8-3 shows estimates of the potential incremental costs to agriculture that may be needed to reduce 

nutrients to levels that attain EPA’s criteria. EPA derived these estimates by multiplying the number of 

potentially affected acres in each category of agricultural operation with the unit costs of the owner plus 

typical programs from SWET (2008a). 

Exhibit 8-3: Potential Agricultural Control Costs Associated with Incrementally 

Impaired Lakes and Streams

Agricultural BMP Category Area (acres)1 

Owner plus

Typical 

Program 

Unit Cost 

($/ac/yr)2

Total Owner plusTypical 

Program Costs ($/yr) 

Animal Feeding 1,814 - 1,846 $18.56 $33,700 - $34,300

Citrus 15,482 - 27,343 $156.80 $2,427,700 - $4,287,300

Cow Calf Production, Improved 

Pastures 153,978 - 168,665 $15.84 $2,439,000 - $2,671,700

Cow Calf Production, Unimproved 

Pastures 49,054 - 51,057 $4.22 $207,200 - $215,700

Cow Calf Production, Rangeland and 

Wooded 74,449 - 75,790 $4.22 $314,500 - $320,100

Row Crop 7,846 - 9,808 $70.40 $552,400 - $690,500

Cropland and Pastureland (general)3 152,976 - 160,814 $27.26 $4,169,500 - $4,383,100

Sod/Turf Grass 2,007 $35.20 $70,600

Ornamental Nursery 840 $70.00 $58,800

Dairies 583 - 621 $334.40 $194,800 - $207,800

Horse Farms 1,632 $15.84 $25,900

Field Crop (Hayland) Production 194,181 - 215,168 $18.56 $3,604,000 - $3,993,500

Other Areas4 54,499 - 67,364 $18.56 $1,011,500 - $1,250,300

Total5 709,340 - 782,954 -- $15,109,400 - $18,209,500
November 2010 8. Potential Costs to Agricultural Sources 8-5

Exhibit 8-3: Potential Agricultural Control Costs Associated with Incrementally 

Impaired Lakes and Streams

Agricultural BMP Category Area (acres)1 

Owner plus

Typical 

Program 

Unit Cost 

($/ac/yr)2

Total Owner plusTypical 

Program Costs ($/yr) 

Note: Detail may not add to total due to independent rounding.

1. Based on GIS analysis of land use data from five water management districts (for entire state) and 

FDACS BMP program NOI GIS data layer. Low end reflects acres in incrementally impaired HUCs (that 

are not included in HUCs for baseline impairment) that are not enrolled in BMPs under FDACS; high end 

reflects all acres in incrementally impaired HUCs, regardless of FDACS BMP enrollment.

2. Cost estimates from SWET (2008a); representative of 2010 prices (personal communication with D. 

Bottcher, 2010).

3. Owner/typical BMP unit costs based on average costs for improved pastures, unimproved/wooded 

pasture, row crops, and field crops.

4. Includes FLUCCS Level 3 codes 2160, 2200, 2230, 2400, 2410, 2500, 2540, and 2550.

5. Excludes land not in production.

 

8.3.2 Springs

Florida’s Environmental Quality Incentive Program (EQIP) provides 100% cost share payments for the 

installation of BMPs (FL EQIP, 2009a). The payment amounts reflect statewide average costs of 

implementing the practices on a scale and scope typical in Florida (personal communication with J. 

Bartine, USDA NRCS Florida State Office, July 2009). Payments for nonstructural practices reflect a one 

year practice lifespan (e.g., one year of rotating crop, maintaining records). For nutrient management, 

EQIP provides a payment of $10 per acre for general agriculture and $20 per acre for specialty crop (FL 

EQIP, 2009a).10 EQIP (2009b) notes that this amount is an incentive payment which includes the cost of 

soil sampling, testing and monitoring; the rate is established to encourage the participant to adopt the 

management practice. Note that these costs do not include any cost savings associated with decreased 

fertilizer use or cost of potential crop loss due to under fertilization, and thus EPA may be overstating 

costs. Nutrient management plans may need to be developed every three years.

EPA estimated the cost of nutrient management on land categorized as general agriculture and specialty 

crop. EPA’s GIS analysis of land use data for the state of Florida indicate that these two categories of 

agricultural operations account for approximately 5.9 million acres (4.9 million acres categorized as 

general agriculture plus 1 million acres categorized as specialty crop). Additional analysis of these 5.9 

million acres indicates that 4.2 million acres are in watersheds that are already impaired for nutrients or 

under a TMDL leaving 1.7 million acres potentially affected by EPA’s rule. Furthermore, approximately 

0.6 million of these 1.7 million acres are within incrementally impaired watersheds and thus costs for 

additional BMPs for this land has already been estimated as described in Section 8.3.1. Therefore, EPA 

estimates that at most 1.1 million additional agricultural acres in Florida may potentially require nutrient 

management to attain EPA’s numeric nutrient criteria for springs. 

 

10 FDACS defines specialty crops as fruits, vegetables, tree nuts, dried fruits, horticulture (including floriculture and turfgrass 

sod). 
November 2010 8. Potential Costs to Agricultural Sources 8-6

Exhibit 8-4 shows EPA’s estimate of the potential incremental cost of additional nutrient management 

to protect Florida springs that may result from implementation of EPA’s numeric nutrient criteria. EPA 

estimated these costs by multiplying the number of potentially affected agricultural acres with the unit 

costs described above. Note that this estimate does not account for the actual locations of incrementally 

impaired springs, and may exceed actual costs. 

Exhibit 8-4: Potential Agricultural Control Costs Associated with Incrementally Impaired 

Springs

Nutrient Management 

Program Type

Total Acres 

in Florida1 

Acres Needing 

Nutrient 

Management2 

Unit Cost 

($/acre)3 Total Cost Annual Cost($/year)4 

General Agriculture 4,885,643 1,003,973 $10 $10,039,700 $3,825,700

Specialty Crop5 1,057,107 120,558 $20 $2,411,200 $918,800

Total 5,942,750 1,124,531 -- $12,450,900 $4,744,400

1. Excludes unimproved and woodland pastures, abandoned groves, aquaculture, tropical fish farms, open 

rural lands, and fallow cropland.

2. Calculated by subtracting agricultural land in incrementally impaired watersheds needing controls and 

agricultural land types participating in FDACS BMP program (assuming all Tri-county agricultural area land 

is regular nutrient management land) from total land use area in Florida.

3. Source: FL EQIP (2009a). 

4. Costs annualized at 7% over 3 years.

5. Specialty crop land use types include row crops, citrus groves, fruit orchards, other groves, nurseries and 

vineyards, sod farms, and floriculture.

8.4 Summary of Potential Costs to Agricultural Sources

Exhibit 8-5 summarizes the estimated costs to agricultural operations that could potentially be indirectly 

associated with EPA’s numeric nutrient criteria.

Exhibit 8-5: Potential Annual Incremental Control Costs for Agricultural Sources

Waterbody Type Acres Needing BMPs Annual Costs1 

Lakes and Streams 709,340 - 782,954 $15,109,400 - $18,209,500

Springs 1,124,531 $4,744,400

Total 1,833,871 – 1,907,485 $19,853,900 - $22,953,900

1. For lakes and flowing waters, low cost reflects owner/typical BMP program estimated by SWET (2008a) 

for the Caloosahatchee River and St. Lucie River watersheds for all acres in incrementally impaired 

watersheds not enrolled in FDACS BMP program; high cost represents a more aggressive level of control 

on all agricultural acres in the incrementally impaired watersheds based on the alternative program from 

SWET (2008a). For springs, costs represent implementation of nutrient management on all farms in the 

state not located in a baseline or incrementally impaired watershed.

 

Under the FDEP 2009 draft nutrient criteria baseline, annual incremental costs to agricultural sources 

could be up to $2.1 million, as described in Appendix A.
November 2010 9. Potential Costs to Septic Systems 9-1

9. Potential Costs for Septic Systems 

Discharges from septic systems in Florida do not require surface water discharge permits. However, state 

implementation of EPA’s numeric nutrient criteria may affect these systems through the identification of 

additional impaired waters and subsequent TMDLs and BMAPs. This section provides estimates of 

potential controls and costs that may be needed to attain EPA’s criteria. These estimates are only 

approximations for informational purposes; actual costs will depend on site specific conditions and 

control strategies. 

9.1 Data

EPA obtained the locations of septic systems in Florida from the FDOH GIS data file of OSTDSs

inspected by the Department’s Bureau of Onsite Sewage (FDOH, 2010a). Although FDOH published 

these data in April 2010, the FGDL metadata indicate that they represent septic systems as of 2007. These

data indicate that there are 935,203 septic systems in Florida, of which 793,697 are active. However, 

FDOH also reports that 2.67 million permit applications for new septic systems have been cumulatively 

received (FDOH, 2009). Because the cumulative number of new septic system permits does not reflect

septic systems taken out of service, and the FDOH does not provide the locations of these systems, EPA 

used the data from the 793,697 active septic systems provided by FDOH (2010a) to estimate the septic 

systems near incrementally impaired waters. 

9.2 Method

Nutrient reductions from septic systems could be necessary under EPA’s rule. Implementation strategies 

could include upgrading existing systems to advanced nutrient removal and connecting households and 

businesses that use septic systems to centralized wastewater treatment. The feasibility of connecting to 

centralized treatment compared to septic upgrades would depend on existing wastewater treatment 

capacity and the costs of the connections. For example, Monroe County estimates that it would cost 

approximately $15,000 per household to connect to a sewer system, including costs for connection and 

sewer piping, septic tank destruction, and treatment plant construction and upgrades. 

Because of the cost, time, and issues associated with new wastewater treatment plant construction, EPA 

assumed that upgrading septic systems would in most cases be the lower cost and more feasible 

compliance strategy for nutrients. In areas where existing centralized treatment capacity is available, 

typical connection costs are also likely to exceed average septic system upgrade costs. For example, the 

City of Jacksonville (2003) estimates that connection costs average $17,840 per house ($15,000 in 2003 

dollars, updated to 2010 dollars using Southern Region CPI), while the Florida Government Utility 

Authority (2009) estimates a range of $5,130 to $15,140 per house for 188 houses in Lehigh Acres. These 

costs are significantly higher than upgrading existing septic systems as described in Section 9.3. 

9.2.1 Lakes and Streams

Most of the existing nutrient-related TMDLs for lakes and streams identify failing septic systems as 

contributing to nutrient impairments in surface waters. Those septic systems in close proximity to surface 

waters are likely to contribute the greatest load to the waterbody. For example, for the Middle St. Johns 

River Nutrient TMDL, FDEP included wastewater from failed septic tanks within 50 feet as direct 

discharges of untreated wastewater to the stream network; for those outside of the 50-feet boundary, 

FDEP combined septic system loads with the nonpoint source loading for residential areas (Gao, 2009). 
November 2010 9. Potential Costs to Septic Systems 9-2

Properly operated and maintained systems usually provide treatment equivalent to secondary wastewater 

treatment (Petrus, 2003). However, even properly functioning septic systems could impact water quality, 

depending on septic system location. Site specific data would be needed to determine which septic 

systems are contributing to nutrient impairments and the magnitude of that contribution. In the absence of 

site specific data on the contributions of septic systems to nutrient loadings in the incrementally impaired 

watersheds, EPA assumed that systems located within 500 feet of waterbodies in the incrementally 

impaired watersheds may need to reduce nutrient loads. The GIS analysis indicates that there are 

approximately 8,224 septic systems within 500 feet of water in the incrementally impaired watersheds.

9.2.2 Springs

The contribution of nitrogen from septic systems to springs is highly uncertain and likely site specific. For 

example, Brown et al. (2008) found that the preponderance of nitrogen pollution in Florida springs 

appears to be from fertilizer sources; most of the accumulated evidence from mass balance computations 

and isotopic tracer studies suggests that mineral fertilizers, and therefore, not septic tanks and wastewater 

sprayfields, are the principal sources of nitrogen pollution in Florida springs. Thus, because EPA has 

already estimated costs for nutrient management on all crop land not already being controlled for existing 

or incremental impairments, EPA assumes that no additional controls would be needed for septic systems 

to attain the nitrate-nitrite criterion for springs. 

9.3 Potential Costs 

Repair of failed septic systems would be necessary with or without EPA’s numeric nutrient criteria

(system failure is generally manifest by failure of wastes to be discharged from interior pipes). However, 

these repairs would not necessarily include upgrades to systems that could reduce nutrient loadings to 

surface and groundwater. Therefore, EPA estimated the cost to upgrade conventional septic systems to 

advanced nutrient-reducing systems regardless of existing functionality. 

Biomicrobics manufactures the RetroFAST system as a retrofit of existing septic systems to improve 

nutrient removal (the system is added to existing septic tank and drainfield systems). The system is a 

fixed-film activated sludge process and ranges from $1,650 plus an additional $400 to $500 for 

installation (Wastewater Technologies, 2010). Capital cost for the upgrade could range from 

approximately $2,000 to $2,100. Anderson et al (1998) indicated that the system can achieve average TN 

concentrations less than 11 mg/L and TP concentrations of 5.4 mg/L. SeptiTech also manufactures an 

onsite wastewater treatment system utilizing fixed film biological filters. The system costs approximately 

$3,000 to $4,000 to install (Everhart, 2009) and can consistently achieve effluent TN concentrations less 

than 10 mg/L in warmer weather (14 mg/L average over 12 month study period in Massachusetts) (U.S. 

EPA, 2003c). 

Aquapoint manufactures the Bioclere onsite wastewater treatment system which uses a fixed film 

biological trickling filter and clarifier to remove organics and nutrients from domestic wastewater. EPA 

(2003b) indicated that TN concentrations from a Bioclere system averaged 16 mg/L over a 13-month 

study period of residential wastewater in Massachusetts. During warmer months effluent concentrations 

were consistently below 10 mg/L. Installation of the system for a single family home to a new or existing 

conventional septic system costs approximately $6,500 (this cost does not include the septic tank and 

drainfield that are already present with existing systems) (McNeer, 2009). 

Pursuant to section 369.318, F.S., the Department of Health (DOH) studied onsite disposal system 

standards needed to achieve nitrogen reductions protective of groundwater quality within the Wekiva 

Study Area. DOH (2004) reported that a conventional septic tank and drainfield costs from $5,500 to 
November 2010 9. Potential Costs to Septic Systems 9-3

$7,000 for a three-bedroom home, and a comparable nitrogen-reducing system with a drip irrigation 

drainfield costs from $7,500 to $9,000 (based on estimates from licensed contractors and engineers that 

design and install nutrient-reducing systems in the area). However, details on the nitrogen-reducing 

system components are insufficient to estimate the incremental costs of upgrading to nitrogen removal. 

For example, it is not clear whether the existing septic tank could be used and the nitrogen-reducing 

technology could be retrofitted or whether the entire system would need to be replaced.

Based on this information, EPA estimated that capital costs for upgrading existing septic systems to 

achieve nutrient removal could range from $2,000 (approximate cost of RetroFAST system for 250 

gallons/day) to $6,500 (cost of fixed film biological trickling filter). For O&M costs, EPA relied on a 

study that compared the annual costs associated with various septic system treatment technologies 

including conventional OSTDS and fixed film activated sludge systems similar to those described above 

(Chang et al., 2010). Chang et al. (2010) estimated the incremental O&M costs for an advanced system to 

be $650 per year. Thus, based on annual O&M costs of $650 and annualizing capital costs at 7% over 20 

years, annual costs could range from approximately $800 to $1,300 for each upgrade. 

9.4 Results

EPA estimated that there are 8,224 active septic systems within 500 feet of water in 10-digit HUCs in 

watersheds that could be identified as impaired based on FDEP’s narrative criterion. The potential annual 

costs associated with upgrading septic systems for attainment of EPA’s criteria may range between 

approximately $6.6 million to $10.7 million. 

Under the FDEP 2009 draft nutrient criteria baseline, annual incremental costs to septic systems could 

range between $1.3 million and $2.2 million, as described in Appendix A.
November 2010 10. Governmental Expenditures 10-1

10. Governmental Expenditures

State implementation of EPA’s numeric nutrient criteria may result in additional costs related to the 

development of TMDLs for waters added to Florida’s 303(d) list of impaired waters. This section 

describes how EPA estimated potential incremental costs associated with increased government

expenditures to develop additional TMDLs. 

10.1 New TMDLs

EPA determined that existing nutrient-related TMDLs in Florida address an average of approximately two 

WBIDs each. Using the average number of WBIDs per TMDL, EPA estimated that 163 additional 

nutrient TMDLs may be required (e.g., 325 incrementally impaired WBIDs ÷ 2 WBIDs per TMDL). 

The process for developing TMDLs in Florida includes (FDEP, 2005): 

 gathering and analysis of data

 meeting quality assurance specifications

 computer modeling

 adoption through state’s public rulemaking process 

 public hearing before adoption 

 development of a BMAP with detailed implementation strategies (1-2 year process after adoption 

with additional public meetings).

FDEP may also hold public meetings after data collection and prior to development of a draft TMDL. 

EPA had previously estimated the cost of developing TMDLs based on performing eight basic steps (U.S. 

EPA, 2001): 

 characterizing the watershed 

 modeling and analyzing the waterbody and its pollutants to determine the reduction in the 

pollutant load that would eliminate the impairment

 allocating load reductions to the appropriate sources

 preparing an implementation plan 

 developing a TMDL support document for public review 

 performing public outreach 

 conducting formal public participation and responding to it 

 management (including tracking, planning, legal support, etc.). 

EPA (2001) indicates that the average cost per cause of impairment is approximately $28,000 nationally, 

but can typically range from about $6,000 to $154,000. The lower end of the range ($6,000) reflects the 

typical cost associated with TMDLs that are the easiest to develop and also have the benefit of maximum 

efficiencies (e.g., a TMDL for another pollutant in the same waterbody). The higher end of the range 

represents the cost associated with TMDLs that are most difficult to develop, and for which there is no 

benefit of related work done on other TMDLs for the waterbody or the watershed. Although the 
November 2010 10. Governmental Expenditures 10-2

establishment of numeric nutrient criteria may reduce these higher end TMDL costs, EPA did not account 

for these reductions in this analysis. 

Because most incrementally impaired waters exceed both TN and TP criteria, EPA assumed that both 

pollutants would be addressed in the TMDL analyses for each set of impaired WBIDs. Thus EPA 

estimated the total cost of TMDLs for each set of impaired WBIDs as the cost of a TMDL for one nutrient 

plus the cost of a second TMDL for the second nutrient. Using this method, EPA estimated TMDL costs 

for each set of impaired WBIDs as approximately $34,000 (the average TMDL cost of $28,000 for the 

first nutrient, plus the low end TMDL cost of $6,000 for the second nutrient). Escalating this cost to June 

2010 dollars11, average per TMDL costs could be approximately $47,000. Multiplying the average cost 

per TMDL ($47,000) by an 163 additional TMDLs results in an estimated total cost of approximately 

$7.7 million. 

Currently, FDEP operates its TMDL schedule based on a five-phase cycle that rotates through the five 

basins over five years (FDEP, 2003). Under this schedule, completion of TMDLs for high priority waters 

will take 9 years; it will take an additional 5 years to complete the process for medium priority waters.

Thus, assuming all the incremental impairments are high priority and FDEP develops the new TMDLs 

over a 9-year period schedule, annual costs would be approximately $851,000. 

Under the FDEP 2009 draft nutrient criteria baseline, annual incremental costs to develop additional 

TMDLs could be approximately $0.3 million, as described in Appendix A. 

10.2 Site Specific Alternative Criteria

As part of FDEP’s 2009 proposed nutrient criteria revisions, FDEP proposed to adopt many nitrogen and 

phosphorus TMDLs as SSAC. Under EPA’s rule, the state could adopt TMDL targets as SSAC as part of 

its triennial review process for minimal costs. Furthermore, costs to develop SSAC under EPA’s rule are 

likely to be similar to what SSAC development costs have been under Florida’s current narrative nutrient 

criteria. Thus, EPA assumed that incremental costs associated with SSAC, if any, would be minimal. 

10.3 Ambient Monitoring

Existing TMDLs and the “Comment” field in the current 303(d) list indicate that state and local agencies 

are regularly monitoring TN and TP in ambient waters. Florida monitors TN and TP levels even though 

the existing criterion is narrative because Florida’s nutrient impairment listing method uses a TSI that is 

calculated based on TN, TP, and chlorophyll-a concentrations. These nutrient criteria data are the basis of 

the extensive IWR database FDEP maintains and which provided baseline water quality data for the 

analyses in this report. Because Florida is currently monitoring TN, TP, and chlorophyll-a concentrations

in many waters, EPA’s rule is unlikely to have a significant cost impact on monitoring activities 

throughout the state. 

 

11 Escalated using the Bureau of Labor Statistics Employment Cost Index for state and local government workers (2001 Index = 

83.6; 2010 Index = 115.4).
November 2010 11. Summary of Potential Costs 11-1

11. Summary of Potential Costs 

The potential costs that may be associated with state implementation of EPA’s numeric nutrient criteria 

for freshwater lakes and flowing waters in Florida may include incremental compliance and government 

resource costs. This section provides a summary of EPA’s estimates of these potential costs. Note that 

these estimates may be overstated because some waters identified as incrementally impaired under EPA’s 

numeric criteria may be currently impaired but unidentified as such under existing narrative criteria. 

11.1 Potential Costs Associated with Incremental Impairments

Exhibit 11-1 summarizes EPA’s estimates of potential annual incremental costs for both point and 

nonpoint sources. For point sources, costs reflect upgrading existing treatment to meet WQBELs based on 

EPA’s numeric nutrient criteria. Urban stormwater costs reflect a scenario of implementing stormwater

controls on all land developed prior to 1982. Agriculture costs reflect implementing owner/typical BMP 

programs developed by SWET (2008a) on all applicable lands in watersheds containing incrementally 

impaired lakes and streams, and costs of applying nutrient management on crop land throughout the state 

(where such activities are not already needed or occurring) to address nitrate-nitrite concentrations in 

springs. Costs for septic systems represents costs of upgrading septic systems within 500 feet of water in 

incrementally impaired watersheds and septic systems located in the most vulnerable incrementally 

impaired spring recharge areas. Government expenditures reflect developing additional TMDLs.

Exhibit 11-1: Summary of Potential Annual Costs Associated with Numeric Nutrient 

Criteria (2010 dollars)

Source Sector Type of Expenditure Annual Cost (millions)

Municipal Wastewater1 BNR to reduce TN and/or TP $22.3 - $38.1

Industrial Dischargers2 BNR to reduce TN and TP; chemical 

precipitation to reduce TP $25.4

Urban Stormwater4 Stormwater controls $60.5 - $108.0

Agriculture5 Owner/typical BMP program $19.9 - $23.0

Septic Systems6 Upgrade to advanced nutrient treatment $6.6 - $10.7

Government/Program Implementation TMDL development7 $0.9

Total -- $135.5 - $206.1

Note: Detail may not add to total due to independent rounding.

BNR = biological nutrient removal; TMDL = total maximum daily load; TN = total nitrogen; TP = total 

phosphorus

1. Based on upgrading existing treatment processes to advanced BNR.

2. Based on extrapolation of average annual costs per flow for random sample of dischargers stratified by 

industrial category.

4. Based on median stormwater control costs from FDEP (2010a), and scenario of need for structural 

controls on land developed before 1982.

5. Based on implementing nutrient management on all crop land outside of incrementally and baseline 

impaired watersheds and scenarios in which all agricultural land not enrolled in the FDACS BMP program in 

incrementally impaired watersheds incurs owner/typical program costs from SWET (2008a) or all 

agricultural land in incrementally impaired watersheds incurs owner/typical costs based on SWET (2008a).

6. Based on upgrading to advanced nutrient removal active septic systems within 500 feet of water (based on 

GIS land use data) in incrementally impaired watersheds.

7. Based on average costs to complete TMDLs for incrementally impaired waters under a 9-year schedule.
November 2010 11. Summary of Potential Costs 11-2

Under the FDEP 2009 draft nutrient criteria baseline, total annual incremental costs could range from 

$17.5 million to $27.2 million, as described in Appendix A. 

11.2 Uncertainties of Analysis 

The estimates of potential incremental costs associated with state implementation of EPA’s numeric 

nutrient criteria for lakes and flowing waters in Florida are based on several assumptions that may over- 

(+) or underestimate (-) actual costs. Exhibit 11-2 provides a summary of the key uncertainties.

Exhibit 11-2: Uncertainties of the Analysis

Uncertainty/Assumption

Potential Impact

on Cost 

Estimates

Comment

Waters under nutrient-related TMDLs and

on the 303(d) list of impaired waters due to

nutrient-related causes represent all waters 

currently impaired for nutrients.

+ 

Some currently impaired waters that are 

as yet unidentified could eventually be 

identified as impaired under Florida’s 

narrative criteria absent EPA’s rule. Costs 

associated with these impairments are 

attributed to EPA’s rule in the current 

analysis.

Inadequate information on treatment train 

for all WWTPs. + 

Assumed need upgrade if information

was inadequate. These WWTPs may in 

fact already have treatment capable of 

achieving TN and/or TP levels equal to 

advanced BNR. 

Costs for urban runoff are based on 

installing structural controls on all pre-1982 

land potentially needing reductions.

+ 

Many baseline requirements under other 

regulations have not been fully 

implemented (e.g., MS4 SWMPs). Thus, 

additional reductions from pre-1982 land 

may not be necessary. 

Costs of nutrient management not 

reflective of potential cost savings. + Nutrient management may result in net cost savings.

Costs for municipal WWTPs based on 

upgrade to advanced BNR. – More costly controls could be required.

Costs estimated only to dischargers in 

Florida. – 

Dischargers in upstream states could 

potentially receive revised effluent limits 

on the basis of EPA’s numeric nutrient 

criteria for Florida. 

Identification of incrementally impaired 

WBIDs are based on FDEP’s 2009 

proposed data requirements for calculating 

annual geometric means (i.e., at least 4 

observations per year, one from each 

season).

? 

The listing method ultimately adopted is 

uncertain. If less stringent data 

requirements are used to determine 

impairments, the number of impairments

could change. 

Agricultural costs include scenario of farms 

implementing owner and typical BMP 

programs on all acres in incrementally 

impaired watersheds.

? 

In some watersheds, point source 

controls may be sufficient to achieve the 

necessary reductions. In other watersheds, 

a more aggressive level of controls for 

agriculture may be needed.
November 2010 11. Summary of Potential Costs 11-3

Exhibit 11-2: Uncertainties of the Analysis

Uncertainty/Assumption

Potential Impact

on Cost 

Estimates

Comment

Costs to industrial dischargers are based on 

random sample of dischargers stratified by 

industrial sector.

? 

Discharger sample may not be 

representative of all dischargers in each 

sector. Actual costs may be higher or 

lower than average sample costs.

Costs for urban runoff are based on 

average load reductions needed from urban 

sources in existing TMDLs (50%). 

? 

Actual reductions and acres needing 

controls in incrementally impaired waters 

could be lower or higher (based on 

existing TMDLs, the contribution of 

urban sources to total nutrient loadings 

varies from 5% to 85%).

Costs for municipal WWTPs are based on 

design flow despite only portion of effluent 

discharging to surface waters.

? 

Dischargers may only need to size 

treatment to discharge flow if a portion of 

the effluent is used for reuse applications.

TMDL costs do not reflect reduced efforts 

provided by the establishment of numeric 

criteria.

+ 

Numeric criteria may reduce costs 

associated with modeling and analysis to

determine the reduction in the pollutant 

loads required.

BMPs = best management practices

BNR = biological nutrient removal

FDEP = Florida Department of Environmental Protection

MS4 = municipal separate storm sewer system

TN = total nitrogen

TP = total phosphorus

WBID = waterbody identification

WWTP = wastewater treatment plant

Key:

“+” = impacts likely overstated

“–“ = impacts like understated

“?” = direction of impact is uncertain
November 2010 12. Benefits of Reducing Nutrient Loads to Lakes and Flowing Waters in Florida 12-1

12. Description of Benefits of Reducing Nutrient Loads to Lakes and 

Flowing Waters in Florida

Elevated concentrations of nutrients in lakes and flowing waters in Florida may result in adverse 

ecological effects, and, as a result, decrease provision of environmental goods and services and impair 

designated uses. Conversely, reduction in nutrient concentrations to meet numeric standards will improve 

ecological function and enhance provision of environmental goods and services and help to attain or 

maintain designated uses. The following sections discuss the general effects of nutrients on lakes and 

flowing waters and qualitatively assess the potential for benefits from nutrient reductions and future 

limitation that may result from implementation of the rule. 

12.1 Effect of Nutrients on Lakes and Flowing Waters

The influence of growth-limiting chemical or nutrients, particularly nitrogen and phosphorus, on water 

quality, biota, and habitats of freshwater aquatic ecosystems is profound. When supplied in excess 

amounts by man’s activities, elevated nutrient concentrations can lead to a series of predictable changes in 

the chemical and physical environment with resultant shifts in water quality and aquatic communities, a 

process which is commonly referred to as anthropogenic eutrophication (Smith 1999, Wetzel, 2001). The 

following sections provide general information on the ecological impacts of nutrients and the 

eutrophication process on lakes and flowing waters.

12.1.1 Ecological Effects

Eutrophication is defined as an increase in organic carbon to an aquatic ecosystem caused by primary 

production stimulated by excess nutrients, typically compounds containing nitrogen or phosphorus (U.S. 

EPA, 2010c). Eutrophication is a major concern for many lakes and flowing waters within the United 

States and is particularly severe for many Florida inland waters. Florida’s 2008 Integrated Report reported 

approximately 1,000 miles of flowing water and 350,000 acres of lakes impaired for nutrients, with

nutrients ranked as the fourth most common source of impairment (FDEP, 2008). 

For most freshwater environments, the growth-limiting nutrient (i.e., the chemical which largely controls 

the rate of primary production) is phosphorus such that it is the reduction in the supply of phosphorus that 

is the primary focus of most freshwater nutrient TMDLs. Nitrogen can be growth-limiting under certain 

circumstances and may play an important seasonal role in freshwater production and shifts in algal taxa 

dominance (e.g., in late summer), but nitrogen is generally more important in estuaries or marine coastal 

waters. 

Eutrophication can lead to a predictable sequence of ecological effects and ultimately to environmental 

degradation, including increases in the occurrence and intensity of water column phytoplankton, including 

harmful algal blooms (e.g., nuisance and/or toxic species), loss of critical submerged rooted aquatic plants 

(or macrophytes), and reduced and/or diurnally variable DO. In turn, ecological degradation can lead to 

significant losses in environmental goods and services provided by the affected waterbodies (e.g., reduced 

recreational fishing and swimming opportunities and reduced quality of drinking water sources). Exhibit 

12-1 provides a conceptual model of the potential ecosystem response to nutrients and how the resulting 

ecological effects translate into impacts to benefits and services. 

As illustrated in Exhibit 12-1, external nutrient loads are the driving factor in the ecological impacts, but 

their relative impact can be significantly affected by mitigating factors of light (color, turbidity), river and 
November 2010 12. Benefits of Reducing Nutrient Loads to Lakes and Flowing Waters in Florida 12-2

lake hydrodynamics (hydraulic residence time, depth), and biotic interactions (e.g., zooplankton grazing). 

It is typically the interplay between nutrients and the mitigating factors that produces a site specific

response for a particular lake or river, such that equal amounts of phosphorus may have quite variable 

growth responses in different environmental settings. 

Exhibit 12-1: Eutrophication Impacts and Responses for Lakes and Flowing Waters 

Source: Adapted from Dodds et al. (2009).

Exhibit 12-1 shows the primary responses of eutrophication, categorized as algal dominance changes, 

decreased light availability, and increased organic decomposition. As nutrients increase, the primary 

responses can lead to more severe and problematic secondary responses, which are typically the more 

readily observable manifestations of ecosystem degradation. These secondary responses include harmful 

algal blooms, loss of submerged aquatic macrophytes, and low DO. In flowing wadeable or shallow 

waters, nutrient enrichment can lead to increases of attached benthic algae (i.e., periphyton); whereas 

deeper or slow-flowing waters will develop phytoplankton blooms more similar to lakes. The sections 

below provide additional discussion of these primary and secondary responses to eutrophication;

Appendix C contains specific details on the quantitative relationship between nutrients and some of the 

primary and secondary responses.

12.1.2 Primary and Secondary Eutrophication Responses 

Increases in the supply of phosphorus and nitrogen can lead to increased amounts of primary production 

in the form of phytoplankton in the water column. The strong positive relationship between phosphorus 

supply and increased algal growth (often measured as concentrations of the primary photopigment 

chlorophyll-a) has been well-developed and modeled for lakes (e.g., Vollenweider, 1968; Dillon and 

External 

Nutrients Mitigating Factors Primary Responses

Secondary 

Responses Impacts on Human Life

Nitrogen and 

Phosphorus

Color

Residence time

Depth

Turbidity

Grazing

Algal Dominance 

Changes

Shift to blue-green 

algae

Benthic Dominance 

to Pelagic 

Dominance

Harmful Algae

Nuisance Blooms

Toxic Blooms

Increase of Algal Toxins

Drinking Water 

Human Health 

Contact Recreation 

Agricultural Water Supply 

Tourism 

Recreational Fishing .

Decreased Light 

Availability

Extreme Chl-a 

Concentrations

Reduced 

Periphyton Growth

Loss of Aquatic 

Macrophytes

Spatial Coverage

Species Diversity

Loss of Habitat

Recreational Fishing 

Tourism 

Increased Organic 

Decomposition

Extreme Chl-a 

Concentrations

Bacterial 

Respiration

Low Dissolved 

Oxygen

Anoxia/Hypoxia

Altered Redox 

Chemistry

Biological Stress

Fish Kills

Recreational Fishing 

Tourism

Impacts on Aquatic 

Life

Increase of Algal 

Toxins

Diversity

Organism condition

Ecosystem function

Loss of Habitat

Diversity

Organism condition

Ecosystem function

Fish Kills

Diversity

Organism Condition 

Ecosystem function

Aesthetics

Tourism

Smell/Taste (Drinking Water)
November 2010 12. Benefits of Reducing Nutrient Loads to Lakes and Flowing Waters in Florida 12-3

Riegler, 1974; Schindler, 1974; Smith et al., 1999), including Florida lakes (Brown et al., 2000). As 

nutrient loading increases, lake trophic state can change from a poorly-fertilized, low productivity 

waterbody (termed oligotrophic) to a moderately-fertilized, moderately productive (mesotrophic) to a 

well-fertilized, highly productive (eutrophic) system, or even an extremely productive, highly degraded 

(hyper-eutrophic) system (Wetzel 2001). 

Eutrophic lake systems typically maintain high concentrations of phytoplankton (i.e., algal blooms) 

during the growing season, which for Florida is essentially year-round. Increasing eutrophication often 

shifts the water column phytoplankton community to one dominated by bloom-forming blue-green algae 

species (e.g., Anabaena, Anacystis, Aphanizomenon, Microcystis) which often have physiological 

advantages over other phytoplankton taxa under conditions of low light, high grazing, warm temperatures, 

and low nitrogen to phosphorus supply ratios (Smith, 1999). High concentrations of blue-green algae 

(cyanobacteria) constitute harmful algal blooms (HABs) due to their potential to form nuisance surface 

scums, sharply reduce light penetration into the water, provide poor grazing material for zooplankton and 

young-of-year fish, and produce irritating or toxic compounds (e.g., cyanotoxins). High concentrations of 

cyanotoxins have been found to cause acute and chronic health problems in humans and fatal poisoning in 

other animals, fish, and birds (Williams et al., 2001). Florida lake systems which contain persistent 

cyanobacterial blooms include Lake Okeechobee, the Harris chain of lakes (Apopka, Griffin, Eustis, and 

Harris) and the St. Johns, St. Lucie, and Caloosahatchee rivers (FWRI, 2009). 

The relationship between nutrients, algal dominance and flowing waters is more complicated since, in 

some systems, other limiting factors such as light availability, substrate type, and hydrologic regime are 

more critical for growth. However, Smith et al. (1999) considered nutrient limitation in flowing waters to 

be common and widespread. Nutrient enrichment of flowing waters can lead to increases in the biomass 

of suspended and attached algae or periphyton (Dodds et al. 1998). McCormick et al. (1996) looked at the 

relationship between periphyton growth and water quality along a nutrient gradient in waterways in the 

northern Florida everglades. These investigators noted reductions in algal growth potential and 

bioaccumulation best statistically explained by decreasing levels of total phosphorus. 

In shallow or wadeable waters, nutrients can lead to accumulation of thick, filamentous green algae (e.g., 

Cladophora), which can adversely affect stream metabolism and biotic communities or decrease the 

aesthetic appeal of the waters (Smith, 2003). In deeper and slower flowing river systems, nutrient-fueled 

phytoplankton accumulation in the upper waters may be more similar to lake settings and can reduce the 

growth of attached periphyton due to light limitation. This light limitation shifts the location of major 

primary production from the bottom (benthic) to the water column (pelagic) environment. 

The reduction of light levels (i.e., decreased depth to which light penetrates or eutrophic zone) due to 

water column algal blooms and turbidity also can adversely affect submerged aquatic macrophytes in a 

lake, including their spatial coverage, species composition, and amount of primary production. The depth 

of maximum depth of macrophyte colonization is dependent on the water clarity, as indicated by Secchi 

disk transparency (SDT) depth, in Florida lakes and elsewhere (Canfield et al. 1985). Eutrophication can 

cause a shift in shallow lakes from a clear water, aquatic vegetation-dominated lake (i.e., most of primary 

production coming from rooted aquatic plants) to a highly turbid, phytoplankton-dominated lake with 

little or no submerged aquatic vegetation (Scheffer, 2001). In addition to the loss in primary production 

and reduced food for herbivorous wildlife (e.g., muskrats, manatees), the loss of the aquatic vegetation 

has the additional ecosystem effect of reducing refuge habitat for zooplankton against fish predators. This 

condition may exacerbate the turbidity of the water, as the reduced herbivorous zooplankton population 

no longer controls phytoplankton biomass by grazing. 
November 2010 12. Benefits of Reducing Nutrient Loads to Lakes and Flowing Waters in Florida 12-4

Eutrophication can lead to increased levels of organic carbon accumulations in the water column (Smith, 

2003). When the algal blooms die, sink, and decay, the decomposition of the excess organic carbon leads 

to increased bacterial respiration, particularly in the lower depths of lakes or in the sediments. This 

increased oxygen demand can greatly reduce DO resulting in conditions of hypoxia (reduced DO) below 

water quality standards or even anoxia (lack of DO) in the deep or overlying waters. Shallow eutrophic 

waters may also be subject to large diurnal swings in DO as highly productive waters produce excess 

oxygen via photosynthesis during daylight hours which is driven to low levels at night by elevated 

respiratory demand. These diurnally variable conditions can lead to biological stress with alteration or 

complete elimination of aquatic biota (e.g., fish kills). 

In addition to the biological stress it produces, reduced or absent DO can also lead to altered reductionoxidation (redox) chemistry. Low redox conditions can result in increased ammonia concentrations in the 

water column and internal recycling of phosphorus from the sediment. The former can be toxic to aquatic 

life under certain temperature and pH conditions and the latter can be problematic to lake restoration since 

reduction in nutrient concentrations in the incoming water (due to the numeric criteria) may not be 

sufficient to overcome internal recycling of accumulated phosphorus in the sediment for many years, 

unless the latter input is treated. 

12.1.3 Mitigating Factors

As indicated in Exhibit 12-1, there are several mitigating factors that will potentially influence the degree 

or magnitude of response of a waterbody to eutrophication. The amount of color in the water (i.e., the tint 

due to dissolved substances, independent of suspended material) influences the potential nutrient-based 

productivity. Highly colored waters will not be as susceptible to nutrient addition as the depth of light 

penetration will be attenuated and primary productivity lessened. This is one of the bases for 

distinguishing between color and clear waterbodies with regard to nutrient criteria (U.S. EPA, 2010c). 

Turbidity due to suspended inorganic particles (silts and clays) will also tend to reduce productivity due to 

both light limitation and the adsorption of phosphorus to the clay particles. 

Hydraulic residence time (sometimes expressed as its reciprocal, the flushing rate) can mitigate the effect 

of nutrients, particularly in flowing waters. If the residence time is sufficiently short, algal blooms will 

not develop as the growing cells are quickly washed downstream and do not accumulate in the water 

column. At the same time, where such nutrient-laden flowing waters are detained by impoundments, 

residence time increases, and significant algal blooms may develop. 

Depth is an important factor in determining the level of production since deeper lakes tend to be less 

productive than shallow lakes. This is due to the euphotic zone (i.e., depth to which light penetrates) 

occupying a greater proportion of the volume of a shallow lake, as well as the greater probability for 

thermal stratification to occur in deeper lakes. Algae sinking in a thermally stratified lake are much less 

likely to be re-suspended than in a shallow one. 

Grazing refers to the ingestion of the phytoplankton by herbivorous zooplankton. Zooplankton can be an 

important controlling mechanism for preventing algal blooms to develop. In flowing waters and river, 

grazing is conducted by benthic macroinvertebrates feeding off the accumulated periphyton. In either 

setting, the fish community can greatly influence the biomass and effectiveness of the grazers in 

controlling the primary producers. This influence is the basis for lake restoration through the technique of 

biological manipulation. 
November 2010 12. Benefits of Reducing Nutrient Loads to Lakes and Flowing Waters in Florida 12-5

12.2 Impacts of Nutrients on Environmental Goods and Services

Eutrophication of lakes and flowing water may have a significant impact on the value of environmental

goods and services provided by the affected waterbodies. Dodds et al. (2009) estimated that the potential 

annual value of losses to recreational water usage, waterfront real estate, spending on recovery of 

threatened and endangered species, and drinking water treatment due to eutrophication of freshwaters in 

the United States is about $2.2 billion per year. 

In Florida’s environment and economy, the goods and services provided by springs are particularly 

valuable. The state has more first-magnitude springs than any other state or country, and these are used 

for a variety of recreational activities including swimming, tubing, kayaking, scuba diving, camping, 

canoeing, and snorkeling (Bonn and Bell, 2003). They also serve as critical habitat for manatees, and as 

such are popular manatee-watching destinations. These characteristics make spring water quality 

maintenance particularly important to Florida’s economy. For example, Bonn and Bell (2003) conducted 

an economic valuation study of four of Florida’s largest springs (Wakulla, Ichetuknee, Homosassa, and 

Volusia Blue Springs). They found that spending by visitors at each of these springs ranged from $10 

million to over $23 million in 2002 (see Section 12.3.2 for a more detailed discussion of tourism sector 

impacts).

12.2.1 Impacts of HABs

Exhibit 12-1 shows the link between eutrophication in lakes and flowing waters and the provision of 

environmental goods and services. For example, the occurrence of nuisance or toxic HABs adversely 

affects a number of designated water uses including: drinking water supply, contact recreational activities, 

fishing, and agricultural water supply, and may also pose human health risks. Reductions in recreational 

opportunities (e.g., decrease in catch rates), decline in aesthetic value, adverse public perceptions of the 

safety of polluted water, and potential exposure to health risks may also adversely affect tourism, both 

locally and at the state level. 

The major HAB group of concern for lakes and flowing waters are the blue-green algae (Cyanophyta) 

which pose a toxic risk to mammalians including wildlife, livestock, pets, and humans due to the presence 

of cyanotoxins and other toxic compounds released when the algae decay. Blue-green algae toxins are 

classified according to mode of action and include hepatotoxins (e.g., microcystins), neurotoxins (e.g., 

anatoxins), skin irritants, and others (WHO, 2003). Microcystins, in particular, have been associated with 

acute liver damage and possibly liver cancer in laboratory animals. Severe morbidity and mortality in 

domestic animals due to toxin-contaminated drinking water has been documented (WHO, 2003). 

Researchers are identifying increasing numbers of cyanotoxins (over 70 and growing), and the potential 

implications to human health are not fully understood at this time (WHO, 2003). 

Contact recreation includes swimming and other activities (e.g., jet-skiing, kayaking) where direct 

exposure of skin to water is likely. Swimmers’ direct contact with water makes them susceptible to 

irritants or toxins associated with certain types of HABs that may occur with nutrient pollution (Fleming 

and Stephan 2001). A massive blue-green bloom in the St. Lucie River (probably associated with 

discharge of nutrient-rich water from Lake Okeechobee) led to the posting of health warning signs by the 

Martin County Health Department cautioning the public to avoid contact with the affected water 

(Earthjustice, 2006; U.S. EPA, 2010d). 

Williams et al. (2001) surveyed the levels of toxins occurring in a large number of Florida’s lakes. The 

study sampled 167 sites throughout the state, and found that the phytoplankton community in 88 of the 

samples, taken from 75 different bodies of water, were dominated by toxigenic (toxin-producing) 
November 2010 12. Benefits of Reducing Nutrient Loads to Lakes and Flowing Waters in Florida 12-6

cyanobacteria. Decreased levels of nutrients associated with the numeric nutrient criteria would reduce 

the number of HABs and thus reduce toxin levels and health risk to swimmers. 

Elevated nutrient levels can also significantly affect the potability of water for livestock, particularly if 

they facilitate the growth of high concentrations of blue-green algae. Numerous occasions of livestock 

poisoning have been noted from Australia (Stewart et al, 2008) but the earliest record of algal toxins in 

Florida were reported in association with the death of cattle near Lake Okeechobee in the 1980s 

(Carmichael, 1992). Dead cattle, toxic responses in laboratory mice, and contact irritation were found in 

association with Anabaena and Microcystis blooms. The Florida Cooperative Extension notes that cattle 

will avoid drinking from ponds overgrown with algae in favor of other water sources. If no other sources 

exist, cattle will decrease their water intake, resulting in poorer growth and lactation (IFAS Extension, 

undated). 

12.2.2 Impacts of Aquatic Vegetation Loss

The loss of aquatic vegetation macrophytes may reduce habitat for zooplankton and young-of-year fish, 

and may shift the fish community towards open-water pelagic species rather than benthic fish species 

typically associated with bottom or weed beds. Investigation of fish and trophic states in Florida lakes 

suggested that fish biomass of recreationally important species may be less affected by increases in 

nutrients than in northern temperate lakes, but that community shifts do occur (Bachmann et al., 1996). 

12.2.3 Impacts of Degraded Water Quality

Low ambient DO concentrations or anoxia adversely affects fish growth and reproductive success and can 

result in shifts in a fish community to low DO tolerant species, reduced growth rates, and more frequent 

fishkills. In stratified lakes with an anoxic bottom layer (i.e., hypolimnion), the available volume of open 

water habitat for fish and zooplankton is reduced. Excess, decaying organic material and low DO often 

lead to unsightly or aesthetically-unpleasing shorelines (sight and/or odor) that discourage beach 

recreational activities and tourism. Unsightly or aesthetically-unpleasing shorelines may also affect 

property values of lakefront housing. 

As noted in Exhibit 12-1, the combination of the presence of HABs, loss of aquatic macrophytes, and low 

DO conditions will impact ecological services such as biodiversity (i.e., the number of species and 

habitats present), organism health (i.e., population viability and reproduction), and ecosystem function 

(e.g., carbon sequestration, nutrient cycling, waste assimilation). The effects of eutrophication in altering 

these types of ecological functions are well-documented (e.g., Smith 2003; Dodds et al. 2009). 

12.3 Types of Benefits Associated with Nutrient Reductions

Implementing nutrient criteria and reducing nutrient concentrations in lakes and flowing waters should 

reduce or prevent the adverse effects of eutrophication and, as a result, enhance the environmental goods 

and services that these waters provide. For impaired lakes and flowing waters, the restoration goal is to 

move these waters from a nutrient-rich, eutrophic state to a mesotrophic or oligotrophic state closer to the 

natural condition of the waterbody. For unimpaired waters, the criteria establish benchmarks for limiting 

loads and preventing a loss of designated uses in the future, thus maintaining beneficial uses. 

Exhibit 12-2 shows the types of benefits often associated with environmental policies, including 

improvements in water quality, and the types of methods that can be used to assign value to such benefits. 

Categories that may be applicable to nutrient reductions in Florida include human health, ecological, and 

other benefits. The sections below discuss the potential for benefits in these categories.
November 2010 12. Benefits of Reducing Nutrient Loads to Lakes and Flowing Waters in Florida 12-7

Exhibit 12-2: Types of Benefits Associated with Environmental Policies

Category Examples Valuation Methods

Human Health Improvements

Mortality risk reductions Reduced risk of fatality from 

cancer and acute risks

Averting behavior, hedonics, 

stated preference

Morbidity risk reductions Reduced risk of nonfatal illness Averting behavior, hedonics, 

stated preference

Ecological Improvements

Market products Harvests or extraction of food, 

fuel, fiber, timber, fur, and leather Production function

Recreation activities and aesthetics Wildlife viewing, fishing, boating, 

swimming, hiking, scenic views

Production function, averting 

behaviors, hedonics, recreation 

demand, stated preference

Valued ecosystem functions

Climate moderation, flood 

moderation, groundwater recharge, 

sediment trapping, soil retention, 

nutrient cycling, pollination by 

wild species, biodiversity, water 

filtration, soil fertilization, pest 

control

Production function, averting 

behaviors, stated preference

Nonuse values Relevant species populations, 

communities, or ecosystems Stated preference

Other Benefits

Aesthetic improvements Visibility, taste, odor Averting behaviors, hedonics, 

stated preference

Reduced materials damage Reduced soiling and corrosion Averting behaviors, production 

function, cost function

Source: U.S. EPA (2000)

Note that there may be a lag (5 to 15 years) between nutrient reductions and associated benefits in lakes 

and flowing waters. Jeppesen et al. (2005) evaluated the long-term effects of reduced nutrient loading in 

35 lake restoration case studies from around the world, separating the effects for shallow (less than 5m) 

and deep (greater than 5m) lakes. Florida lakes are largely shallow and polymictic (i.e., non-seasonally 

stratified). For shallow lakes, Jeppesen et al. (2005) predicted that 10 to 15 years are typically needed to 

have TP concentrations move to a new steady state reflective of the reduced nutrient loads while TN 

response time is faster (typically less than 5 years). 

12.3.1 Human Health Improvements

High concentrations of HABs can pose potential health risk associated with irritants, gastrointestinal 

diseases, and other concerns. Several Florida freshwater areas appear to have chronic cyanobacteria 

blooms, including Lake Okeechobee, the Harris Chain of Lakes (Apopka, Griffin, Eustis and Harris) and 

the St. John and St. Lucie Rivers (Burns, 2008). In May 2010 a health warning was issued to all 

recreational users of the St John River, because of large scale fishkills resulting from toxic cyanobacteria 

in the river. Exposure to the water or dead fish may result in burning eyes, respiratory irritation, or skin 

rash (FDOH, 2010b). To the extent that the criteria and associated nutrient reductions reduce current 

exposures and illness and prevent future exposures and illness, society values these types of reduced

health risks. The cost of illness (COI), including treatment costs and lost wages, can provide a lower 

bound on societal value as a measure of avoided costs (rather than the preferred willingness-to-pay 
November 2010 12. Benefits of Reducing Nutrient Loads to Lakes and Flowing Waters in Florida 12-8

measure of benefits that includes the value of avoided pain and suffering as well as out-of-pocket costs). 

COI values represent a lower bound value because these costs do not include the value of avoiding pain 

and suffering. 

12.3.2 Ecological Improvements

Ecological benefits that may arise from nutrient reductions include market benefits, including those 

associated with withdrawal uses, such as drinking water supplies and agricultural use, and benefits to 

other markets such as ecotourism; recreational uses, such as boating, fishing, and swimming; ecosystem 

functions, such as nutrient cycling and biodiversity; and benefits that are not associated with use of the 

resources (nonuse benefits), such as preservation of species for future generations (existence and bequest 

values).

Market Products

Impacts on Drinking Water Supplies 

Reduced nutrient loading to the lakes and moving waters of Florida should improve potable water supply 

by reducing adverse impacts associated with toxins from blue-green algal (Cyanophyta) species (e.g., 

Microcystis, Cylindrospermum) and the costs of drinking water treatment processes needed to eliminate 

these toxins. The drinking water treatment technology or processes employed to remove cyanotoxins 

depend on the total concentration of the algal toxins, the form of the toxin, and whether it is intracellular 

or extracellular (Westbrick, 2008). Conventional water treatment (coagulation/sedimentation/filtration) is 

generally sufficient to deal with removal of intact algal cells and intracellular toxins. However, removal 

of extracellular toxins due to lysed cells often requires more extensive or advanced treatment processes 

such as application of powered activated carbon (PAC) or granulated activated carbon (GAC), ultraviolet 

light (UV) treatment, and membrane filtration (Westbrick, 2008). 

The temporary or permanent installation of these additional treatments will increase the capital and 

operating costs for the water treatment plant (Steffensen, 2008). For example, Burns (2008) reports that 

PAC during a cyanobacterial bloom costs an average of $10,000 per day, and such blooms typically last 

several weeks. In June 2008, a water treatment plant serving 30,000 people was shut down after a toxic 

blue-green algae bloom on the Caloosahatchee River in Florida threatened the plant’s water supply 

(Earthjustice 2006, U.S. EPA, 2010d).

Other algal blooms may not be directly harmful to humans but may still affect drinking water treatment 

costs. For example, the increased levels of organic material arising from algal blooms of any taxa can also 

increase treatment costs and the resulting concentrations of chlorination disinfection by-products (DBPs), 

including haloacetic acids and trihalomethanes, in treated drinking water (U.S. EPA, undated). 

DBPs are particularly challenging for water treatment operators since they occur at the end of the water 

treatment process and there are often few practicable alternatives to chlorine disinfection for many plants. 

The primary strategies for reducing DBPs are reducing precursor organic material (particularly humic and 

fulvic acids) in the raw water source through watershed protection, reducing nutrients, or in-reservoir use 

of algaecides (Kitchell, 2001). The numeric nutrient criteria will help reduce the amount of phytoplankton 

organic carbon, reduce generation of DBPs, and decrease treatment costs. 

Increased levels of organic material associated with algal blooms can also clog drinking water intakes and 

cause unpleasant tastes and odors in drinking water (Boyd, 1990). Geosmin and 2-methylisborneol (MIB) 

are organic compounds released by cyanobacteria that impart taste and odor to waters at low 

concentrations, and which are not addressed by conventional drinking water treatment. Chronic taste and 

odor problems can require advanced water treatment such as ozonation, which can be costly. 
November 2010 12. Benefits of Reducing Nutrient Loads to Lakes and Flowing Waters in Florida 12-9

The benefits of reducing algal blooms (both HABs and non-HABs) are the reduction in health risk, 

reduced water treatment costs (both algaecides in the raw water supply and post-intake treatments), and 

the avoided need to develop alternative raw water sources. If adequate water treatment is not available, a 

temporary water source will need to be substituted (if available). If an alternative water supply is not at 

hand, urban areas may need to be supplied with bottled or tankered water, as has been the case in 

Australia and elsewhere (Steffensen, 2008). Long-term solutions might require the development of new 

raw water supplies, which would involve investments for acquisition of land (if available), regulatory 

review and permitting, development of infrastructure (dams, pumps, pipes), and watershed protection. 

Impacts on Agricultural Water Use 

Florida’s freshwaters provide irrigation water for crops and livestock watering supplies. While elevated 

nutrient concentrations in irrigation water would not adversely affect its usefulness for plants (in fact, a 

slight benefit might occur), concerns exist for potential residual effects due to contaminants entering the 

food chain. More importantly, eutrophication sponsors cyanobacterial blooms that can kill livestock and 

wildlife that drink the contaminated surface water. 

The reduction of nutrients due to adoption of the numeric criteria would provide benefits in increased 

cattle production or avoided cost due to cattle sickness or death. However, it would be difficult to 

attribute benefits to the adoption of nutrient criteria since the ultimate source of the water and the 

nutrients in the livestock water supply may be difficult to trace due to the presence of fertilizers or cattle 

manure in fields adjacent to the water source or from the groundwater (i.e., related BMPs for manure 

control or fertilization may provide the bulk of benefits). 

Impacts on Tourism Sector 

High concentrations of HABs can lead to public health department posting of water quality advisories due 

to potential health risk associated with irritants, gastrointestinal diseases, and other concerns. Reductions 

in inland beach closures due to reducing the magnitude and duration of HABs linked to excess nutrients 

will prevent losses to local economies. Several Florida freshwater areas appear to have chronic 

cyanobacteria blooms, including Lake Okeechobee, the Harris Chain of Lakes (Apopka, Griffin, Eustis 

and Harris) and the St. John and St. Lucie Rivers (Burns, 2008). Although analysis of the cost of an 

inland beach closure in a Florida lake is not available, the impact of HABs in other parts of the country 

has been significant.12 Since lake and beach closures are highly localized and substitute swimming beach 

locations may be available, additional information would be necessary to estimate the economic benefits 

(of avoided lost recreational revenue, monitoring and response activities, health care, etc.) of preventing 

HAB outbreaks in freshwater waters.

Freshwater fishing is a major attraction for both native Floridians and tourists and is a substantial boon to 

the Florida economy. Over three million Floridians and over 900,000 out of state tourists partook in 

freshwater nonboat (i.e., shoreline) fishing in 2007 (FDEP, 2008). Another nearly 2.8 million Floridians 

and nearly one million tourists utilized freshwater boat ramps in 2007, and some of these users are also 

 

12 For example, Seewer (2010) reports that outbreaks of blue-green algae blooms in Grand Lake St. Marys, the largest inland lake 

in Ohio, is adversely affecting the local economy as tourism in the area declines, falling from 737,000 visitors per year to 

687,000 visitors last year. Tourism, in particular visitors to the lake, contributes an estimated $216 million to the local economy. 

The poor water quality has resulted in lost jobs and income at marinas and restaurants, and reduced demand for camp sites, 

cottages, and property. Ohio Department of Natural Resources warned people to avoid contact with the water. Those at greatest 

risk are swimmers who accidentally ingest the water, and people on Jet Skis and boats that are splashed repeatedly.
November 2010 12. Benefits of Reducing Nutrient Loads to Lakes and Flowing Waters in Florida 12-10

anglers. Florida ranks number one nationwide in number of in-state anglers, angler-supported 

expenditures, and angler-supported jobs (FWC, 2010). 

Another source of fishing-related economic impact is tournament fishing. Freshwater fishing 

tournaments, particularly for largemouth bass, are common and widespread in Florida (Florida 

Sportsman, 2010) and can generate substantial revenues. While no Florida-specific dollar estimates were 

available, values are available for bass tournaments in a neighboring state which may be comparable. The 

Georgia Department of Natural Resources (2008) estimates that a major bass tournament can have a $4 to 

$5 million dollar impact on the community in which it is held, and that a championship can have an 

impact of as much as $27 million. Improving water quality in Florida’s freshwater fisheries will increase 

their appeal as tournament sites and may bring additional tournament revenue to Florida. 

Ecotourism is an important sector in Florida’s economy and one which is highly vulnerable to the adverse 

impacts of eutrophication. Water quality aesthetics are directly linked to ecotourism, since tourists are 

drawn by the untouched natural beauty or uniqueness of a particular ecosystem. Florida has many unique 

environments and species which are attractions including major spring areas and manatee congregation 

areas. Thus, the principal benefits to ecotourism are avoiding loss of tourist dollar arising from declining 

attendance at natural attractions or income generated by increased tourism to natural attractions where 

water quality has been restored.

These natural attractions are vulnerable to increased nutrients as documented in springs where water 

clarity has declined so far that glass-bottom boat tours are no longer run. For example the poor water 

quality in Wakulla Spring resulting from increased nitrogen levels and algal blooms has stopped all glassbottom boat tours in the state park (Florida Geological Survey, 2010). Vegetation favored by manatees 

has been shaded out by nuisance epiphytes or phytoplankton. There is a strong indication that elevated 

nitrogen (nitrate levels) is the major nutrient stressor for many of these springs (UFWI, 2008), based on 

experimental laboratory data and field evaluations that document the response of nuisance algae to 

nitrate-nitrite concentrations. Controls that reduce nutrient levels in surface waters and applied to the 

watershed (e.g., fertilizer reductions, septic system upgrades) may also reduce nutrients that seep into 

groundwater as well as reduce runoff directly into springs (see Section 8.3.2 and 9.3). 

Preventing deterioration of water quality will avoid the costs associated with a loss of tourism dollars 

associated with reduced clarity and wildlife presence. For example, Bonn (2004) estimated total annual 

direct spending by visitors at 8 different springs at $65 million, generating over $13 million in wages 

created by 1,100 jobs. Bonn and Bell (2003) reported direct economic income from four major Florida 

springs which ranged from $10 million to $23 million, with visitors spending between $19/day to 

$89/day. Freshwater springs are a major attraction for tourists in Florida. There are an estimated 700 

freshwater springs in Florida including 33 major springs where upwelling groundwater flowing at greater 

than 100 cubic feet per second (cfs) provides water of exceptional clarity, fairly constant temperature, and 

ecological richness (FGS, 2004). These properties have created some unique attractions such as glassbottom boat tours, kayaking tours, and snorkeling “with the manatees.”13

Impacts on Property Value 

Due to population growth and development, there has been significant development of lakeshore and 

riverfront properties in Florida. This access to natural waterbodies has been increased by the development 

 

13 See http://www.swimwithmanatees.com/ and http://www.snorkelwithmanatees.com/ for examples.
November 2010 12. Benefits of Reducing Nutrient Loads to Lakes and Flowing Waters in Florida 12-11

of marinas and canal systems that provide boating access in many residential areas. Previous studies 

suggest that waterfront property is more desirable when located near unpolluted water, and therefore 

property values increase with improved water quality and decreased algal blooms and vice versa. 

Improvement of water quality following implementation of the numeric nutrient criteria should result in 

improved water quality and increase waterfront property values. 

Researchers use hedonic property valuation models to quantify the precise difference in property value for 

a given change in water quality in a particular locale. Hedonic models allow estimation of the implicit 

price of a characteristic, which expresses the impact of a unit change in the characteristic on property 

prices. Since water quality in local lakes is a property characteristic, hedonic models can estimate its 

implicit price. For example, Walsh et al. (forthcoming) estimated the property price impacts of changes in 

TN, TP, chlorophyll a (CH), and a compound indicator of water quality, trophic state index (TSI), in lakes 

in Orange County, Florida. The results indicate that improvements in water quality could be worth 

thousands of dollars to individual Orange County properties. It is important to note, however, that this 

method does not account for nonuse values and that there may be some overlap with other values. 

Walsh et al. (forthcoming) used a data set of 55,000 property sales in Orange County during the time 

period 1996-2004, and includes all property sales within 1,000 meters of 146 lakes in the analysis. Walsh

et al. (forthcoming) merged the property sales data with several GIS layers to control for spatial 

characteristics, as well as census block socio-economic data, and matched water quality data from EPA’s 

STORET database and several local municipalities to the lakes using GIS. These multiple data sets allow 

a thorough analysis of the determinants of property prices. In addition to the three variables from the 

numeric standards, Walsh et al. (forthcoming) included the compound indicator TSI, a non-continuous 

combination of TN, TP, and chlorophyll that accounts for the nutrient limiting concept.14 The state of 

Florida uses TSI in several lake regulations. 

Walsh et al. (forthcoming) specified the following econometric model: 

01 2 3 4 5

6

* *

* ' ' ''

P WP WF WQ WF WQ Distance Distance WQ

Area WQ S N

ρ ββ β β β β

β γ φ ψδε

= ++ + + + +

+ + + +++ l t

In the model, 

P = property value 

ρWP = spatially lagged variable

WF = waterfront indicator

Distance = distance to the nearest lake

Area = lake area

WQ = quality indicator

S = property structural attributes

N = location and neighborhood variables 

 

14 Concerns with correlation between the three indicators prevent their simultaneous use in a single hedonic model. The use of 

TSI theoretically allows for a more complete representation of water quality than any of the other individual indicators.
November 2010 12. Benefits of Reducing Nutrient Loads to Lakes and Flowing Waters in Florida 12-12

T = vector of time dummy variables

l = vector of lake dummy variables. 

All continuous variables enter in their natural log form; Walsh et al. (forthcoming) found this to be the 

best functional form for the data. Water quality enters several places in the model; this allows the implicit 

price of water quality to vary over lakefront and non-lakefront homes, distance to the nearest lake, and 

lake area. Finally, Walsh et al. (forthcoming) estimated the full model as a spatial lag model, illustrated 

by the spatially lagged variable (ρWP) on the right side of the equation. This model controls for detected 

spatial dependence in the property prices, which can arise from appraisal practices, neighborhood codes 

and covenants, and similar builders (see LeSage (1998) for more information).

Lakefront homes have the highest implicit prices; nonetheless, sales of non-lakefront homes as far as 600 

meters from a lake can be affected by nutrients. Implicit prices are found to increase with lake size and 

decrease with distance to the nearest lake. Exhibit 12-3 contains the average implicit prices of lakefront 

and non-lakefront homes (represented by homes 250 meters from the lake, a midpoint of distances at 

which non-lakefront homes show property value effects). The values correspond to a 17% change in the 

water quality variable.15 TSI has the highest average lakefront implicit price, while TN has the highest 

average non-lakefront implicit price. 

Exhibit 12-3: Mean Implicit Price of a 17% Change in Water Quality

Pollutant Lakefront1 Non-Lakefront (250 m)1 

TSI $9,761.59 $766.36

TN $8,066.43 $941.21

TP $5,883.09 $256.23

Chlorophyll $3,261.50 $222.35

1. Price in 2002 dollars

To better illustrate the impact of water quality, Exhibit 12-4 contains graphs of the non-lakefront implicit 

price gradients, which show average implicit prices at different distances from the lake.

 

15 A 17% change in average Secchi disk transparency (a popular visibility water quality indicator) for Orange County lakes 

corresponds to a one foot improvement. To compare these results with other studies, this was chosen as the marginal change.
November 2010 12. Benefits of Reducing Nutrient Loads to Lakes and Flowing Waters in Florida 12-13

Exhibit 12-4: Implicit Price Gradients

These results imply that the water quality improvements mandated by the nutrient standards could yield 

considerable property benefits throughout Florida. Although the present results are specific to Orange 

County, it is likely that they are at least similar to other metropolitan areas with comparable population 

density and real estate markets. Exhibit 12-5 contains implicit prices from past hedonic studies of lake 

water quality, representing much less populated areas than Orange County. The results in Exhibit 12-5 

suggest that rural areas in Florida could also see gains in property prices from the nutrient standards. For 

example, Poor et al. (2001) estimate that a one-meter improvement in secchi disk measurement (SDM) is 

worth $3,069 - $10,606 to rural Maine properties. For the same change in SDM, Gibbs et al. (2002) find a 

range of implicit prices of $1,497 - $13,096 (varying over town) in small New Hampshire Towns. 

Overall, a consistent link between water quality and property sales has been found in the literature. 

Exhibit 12-5: Implicit Price of Lake Water Quality in Other Studies

Paper Implicit Price Range1 Location Units Setting

Michael, et al. (2000) $-1,035 - $12,312 ME SDM – 1 m Rural

Boyle and Taylor (2001) $2,361 - $9,444 ME SDM – 1 m Rural

Poor, et al. (2001) $3,069 - $10,606 ME SDM – 1 m Rural

Gibbs, et al. (2002) $1,497 - $13,096 NH SDM – 1 m Small Towns

1. All prices have been adjusted to 2002 dollars using the CPI, obtained from www.bea.gov

Nonmarket Benefits

Recreation and Aesthetics 

The degradation of water resources resulting from high nutrient concentrations may negatively impact 

recreational opportunities. As stated above, high levels of HABs can lead to beach closures, because of 

potential health risk, reducing the occurrence or quality of recreational activities. In addition to health and 

safety concerns, eutrophication may lead to the aesthetic degradation of water resources. Algal and 

cyanobacterial blooms, and particularly surface scums are unsightly and can have unpleasant odors, 

causing beachgoers to go elsewhere even when a beach is not closed, diminishing recreational values. The 

0

500

1000

1500

2000

2500

100 150 200 250 300 350 400 450 500 550 600 650

Dollars

Distance From Lake (m)

Non-Lakefront Implicit Price of 17% 

Change in Water Quality

TSI

TN

TP

CH
November 2010 12. Benefits of Reducing Nutrient Loads to Lakes and Flowing Waters in Florida 12-14

color, clarity, and taste of water adversely impact many recreational activities, including recreational 

fishing, boating, and swimming. 

Eutrophication reduces the amount of DO in a waterbody, leading to fish kills. This in turn leads to fewer 

and smaller fish, and a reduction of the game fish population. Florida ranks number one nationwide in 

number of in-state anglers, angler-supported expenditures, angler-supported jobs, and state and local tax 

revenues derived from fishing (FWC, 2010). In 2007, approximately 3.0 million residents participated in 

non-boat freshwater fishing (FWC, 2010). Approximately 2.8 million Floridians use freshwater boat 

ramps (FWC, 2010). In addition, 2.6 million state residents use non-motorized boats such as kayaks or 

canoes (FWC, 2010). 

Activities that take place near water, such as hiking, jogging, picnicking, wildlife watching, camping and 

hunting, may also be adversely affected by nutrient discharges into the water. While these activities do 

not involve contact with the water, murky and visually unpleasant water and odors may greatly detract 

from the enjoyment gained through these activities. Decreases in fish populations may cause a reduction 

in wildlife near the resource, affecting wildlife viewing and hunting. Additionally, toxic cyanobacteria 

may poison birds and mammals, greatly reducing the wildlife population near a waterbody. For example, 

alligator and bird mortality events during cyanobacterial blooms in Florida lakes may be due to exposure 

to neurotoxic compounds produced during the bloom (Burns, 2008). Pollutants may negatively affect 

local flora and fauna, reducing the aesthetic appeal of the area near the resource and negatively impacting 

wildlife viewing. 

Improved water quality from reducing nutrient discharges will enhance the recreational uses of water 

resources, thereby resulting in welfare gain to recreational users of these resources. Improved water 

quality from reducing nutrient concentrations may translate into three components of recreational 

benefits: (1) an increase in the value of a recreational trip resulting from a more enjoyable experience, (2) 

an increase in recreational participation, and (3) and increase in the available recreational sites. 

Valued Ecosystem Functions 

Attainment of the nutrient criteria should improve ecological functions such as biodiversity and protection 

of sensitive species. Since eutrophication tends to drive ecosystems to physical and chemical conditions 

(turbidity, low DO, highly organic sediments) which are tolerated by a smaller suite of biota, reduction in 

nutrients will likely allow the re-invasion of pollution-intolerant species and increase overall biodiversity 

of species. The reduction of selected fish species due to increasingly more eutrophic states was shown in 

65 Florida lakes (Bachmann et al., 1996). Increased species diversity is often linked to ecological 

resistance to disturbance. 

Richter et al. (1997; as reported in Dodds et al., 2009) reviewed 135 threatened, endangered or special 

concern freshwater species nationwide and found that elevated nutrients were a major stressor in about 

30% of historical and 25% of current cases. Working on the assumption that 25% of all aquatic special 

concern species are nutrient-impacted and, thus, 25% of the cost of species recovery (i.e., restoration) 

costs are due to anthropogenic eutrophication, Dodds et al. (2009) postulated that $44 million per year 

was spent to prevent eutrophication-linked loss of aquatic biodiversity. Information is not available on the 

quantity of threatened, endangered or special concern freshwater species that are found in Florida to 

apportion a percentage of the annual national cost to the state. 

Attempting to isolate the effects of nutrients from other stressors of special concern in Florida and 

elsewhere is difficult. Symbolic threatened and endangered species such as the Florida manatee and 

Florida snail kite are affected somewhat by water quality and nutrient conditions as they affect food items 
November 2010 12. Benefits of Reducing Nutrient Loads to Lakes and Flowing Waters in Florida 12-15

(e.g., aquatic macrophytes, apple snails), although other factors (e.g., water temperature, hydrological 

variation) are also important. 

In the case of the Florida manatee, preferred manatee habitat is characterized by the availability of good 

quality SAV (Smith 1993). In springs, manatees feed primarily on submerged aquatic macrophytes such 

as Myriophyllum spp. and hydrilla (Hydrilla verticillata). As described above, nutrient loading (e.g., 

nitrates) from residential and agricultural sources to springs has promoted the growth of epiphytic algae 

and decreased light transparency, thus reducing available winter forage for manatee in these refuges 

(USFWS 2001). Reduced watershed loadings (see Sections 8 and 9) to meet the nitrate criterion will 

improve the quality of the preferred habitat for this keystone species.

Losses of sensitive species are generally linked to loss of their habitat, either by outright modification or 

elimination or by the alteration of the highly specific combination of physical, chemical or biological

factors that provide the specialized niche. These changes can be attributed to a variety of causes but 

eutrophication can be a major factor since changes in the nutrient regime can lead to differences in the 

way competitive interactions occur between species and shifting dominant species can lead to major 

shifts. 

Nonuse Values 

Even if no human activities or uses are affected by environmental changes caused by nutrient runoff, such 

environmental changes may still affect social welfare. For a variety of reasons, including bequest, 

altruism, and existence motivations, individuals may value the knowledge that water quality is being 

maintained, that ecosystems are being protected, and that populations of individual species are healthy 

independent of any use. It is often difficult to quantify the relationship between changes in pollutant 

discharges and the improvements in societal well-being that are not associated with current use of the 

affected ecosystem or habitat. That these values exist, however, is indisputable, as evidenced, for 

example, by society’s willingness to contribute to organizations whose mission is to purchase and 

preserve lands or habitats to avert development (although some portion of these donations may be 

motivated by use values). Notwithstanding challenges involved in estimation of nonuse values, there is a 

substantial literature devoted to such issues (Bateman et al., 2006). This literature provides insight into 

analysts’ ability to estimate nonuse values within various types of policy contexts, and for various types 

of resources

Various studies have found that individuals are willing to pay for water quality improvements, including 

nutrient reductions affecting wildlife habitat regardless of whether or not they are direct uses (e.g., 

anglers). Shrestha and Alavapati (2004) found that Floridians WTP for water quality improvements in the 

form of phosphorus runoff reductions was $30.24 per household for a “moderate” improvement (31% to 

60%) and $71.17 for a “high” improvement (61% to 90% percent). The authors found values of $49.68 

and $41.06, respectively, for qualitative improvements in wildlife habitat. A recent EPA study found that 

households in EPA Region 4 (which includes Florida) were willing to pay between $4.39 and $7.87 per 

household for water quality improvements resulting from reductions in sediment and nutrient runoffs in 

flowing waters (U.S. EPA, 2009b).

12.4 Avoided Habitat Restoration and Treatment Costs

Establishing numeric nutrient criteria implies that efforts will need to be made to restore waters that 

exceed the criteria. For those waters that do not exceed criteria, the numeric values provide targets with 

which to establish effluent limits and controls on nonpoint sources such that criteria are not exceeded in 

the future. Experience suggests that pollution prevention is less costly than restoration and clean up. Thus, 
November 2010 12. Benefits of Reducing Nutrient Loads to Lakes and Flowing Waters in Florida 12-16

in addition to the benefits associated with attaining WQS in the incrementally impaired waters, the 

benefits of the rule include the impact of the controls in reducing restoration and clean up costs in the 

future. 

In addition, reductions in watershed application of fertilizers to help meet the nitrate criterion (e.g., 

springs) should also reduce the amount of nitrogen that is deposited atmospherically over the landscape in 

the relevant airshed (NADP, undated). Nitrogen derived from volatilization of ammonia into gaseous 

forms that fall associated with wet precipitation or nitrates transported in dust and fine airborne particles 

that are deposited as dryfall should be reduced by stricter fertilizer management, even though the precise 

level of reduction may not be measurable. This reduction in landscape-scale nitrogen deposition should 

help decrease general eutrophication. 

This section describes the cost of efforts that have occurred or are underway to restore waters that are 

impaired under the current narrative criteria. To the extent that such costs are avoided in incrementally 

impaired waters, they represent benefits of implementing numeric nutrient criteria.

Restoration activities and instream or in-lake water treatment can also be used to reduce nutrients loads 

from historical or controlled sources. For example, in Lake Apopka in Florida, the sedimentary store of 

available phosphorus and the moderate hydraulic detention time (2.5 years) resulted in a slow recovery 

(SJRWMD, 2003). To hasten reduction efforts, the SJWMD constructed a wetland system adjacent to the 

waterbody reportedly to remove phosphorus from lake water and permanently bury it in marsh sediments. 

Algae, resuspended sediments, and particle-bound nutrients are removed from lake water as it flows 

through 13 independent marsh cells and returns to the lake (SJRWMD, 2003). 

Another restoration effort that may improve water quality in certain lakes is rough fish harvesting (e.g., 

filter feeding species such as gizzard shad). The presence of filter-feeding species that thrive in turbid, 

algal-dominated water helps to maintain poor water quality conditions by increasing the rate at which 

phosphorus in the water is made available for algal growth, by stirring up loose bottom sediments, and 

removing the larger zooplankton grazers that more efficiently feed on blue-green algae (SJRWMD, 

2003). Removal of the rough fish can significantly improve water quality, including reductions in total 

phosphorus, nitrogen, suspended solids, turbidity, and chlorophyll a concentrations and increased water 

clarity measured by Secchi disk (SJRWMD, 2003). 

Exhibit 12-6 shows TP load reductions and project costs (i.e., potential avoided costs) for habitat 

restoration projects in the Upper Ocklawaha River Basin in Florida. 

Exhibit 12-6: Habitat Restoration and Treatment Costs For Upper Ocklawaha River 

Basin, FL

Project Description TP Reduced 

(lb/yr) Project Cost 

LCWA Nutrient 

Reduction Facility

Water in Apopka-Beauclair Canal 

treated off-line with alum to removes 

TP from Lake Apopka discharge.

5,000 $5,200,000

Suction dredging of 

Western Lake 

Beauclair

Suction dredging to remove 1 million 

cubic yards of sediment in western end 

of Lake Beauclair

Unknown $12,000,000
November 2010 12. Benefits of Reducing Nutrient Loads to Lakes and Flowing Waters in Florida 12-17

Exhibit 12-6: Habitat Restoration and Treatment Costs For Upper Ocklawaha River 

Basin, FL

Project Description TP Reduced 

(lb/yr) Project Cost 

Lake Beauclair 

gizzard shad harvest

Harvest of gizzard shad by commercial 

fishermen removes nutrient from lake, 

reduces recycling of nutrients from 

sediments, reduces sediment 

resuspension, and stabilizes bottom to 

reduce TSS.

Unknown $150,000 (per year in 

2005 and 2006)

Lake Dora gizzard 

shad harvest

Harvest of gizzard shad by commercial 

fishermen removes nutrient from lake, 

reduces recycling of nutrients from 

sediments, reduces sediment 

resuspension, and stabilizes bottom to 

reduce TSS.

Unknown $150,000 (per year in 

2005 and 2006)

Pine Meadows 

Restoration Area

Reduce TP loading from former muck 

farm; restore aquatic, wetland, and 

riverine habitat; chemical treatment of 

soil (alum) to bind phosphates; reduce 

nutrient outflow to feasible level of 1.1 

kg/ha/yr of TP.

1,487 Lake Eustis; 

726 Trout Lake

$1,300,000 (for both 

lakes)

Lake Griffin 

Emeralda Marsh 

Restoration

Wetland restoration, planting, alum 

treatment to bind phosphates in 

sediments; manage excess nutrient 

outflow.

41,450 $15,000,000 (for land 

acquisition)

Lake Griffin gizzard 

shad harvest

Harvest of gizzard shad by commercial 

fishermen removes nutrient from lake, 

reduces recycling of nutrients from 

sediments, reduces sediment 

resuspension, and stabilizes bottom to 

reduce TSS.

Unknown $1,000,000 (spent since 

2002 harvest)

Lake Harris 

Conservation Area

Restoration of former muck farm; 

chemical treatment of soil (alum) to bind 

phosphates for nutrient control; aquatic 

and wetland habitat restoration; reduce 

and manage nutrient outflow to Lake 

Harris to feasible loading of 1.1 

kg/ha/yr, or about 1 lb per acre.

6,665 $550,000

Harris Bayou 

Conveyance Project

Modification of hydrodynamics to 

accommodate higher flows of water. Unknown $5,000,000

Lake Apopka 

Constructed Marsh 

flow-away Phase 1

Lake water pumped through marsh to 

remove particulates and nutrients from 

lake water; designed to treat about 150 

cfs.

External: 4,864; 

flow-away: 17,640 

to 22,050

$19,320,000 ($15 million 

in land acquisition; 

$4.32 million Phase 1 

flow-away construction)

Lake Apopka North 

Shore Restoration

Wetland habitat restoration; remediate 

pesticide "hot spots" in soil. 99,960 $100,000,000 (mostly land acquisition)
November 2010 12. Benefits of Reducing Nutrient Loads to Lakes and Flowing Waters in Florida 12-18

Exhibit 12-6: Habitat Restoration and Treatment Costs For Upper Ocklawaha River 

Basin, FL

Project Description TP Reduced 

(lb/yr) Project Cost 

Lake Apopka 

Habitat Restoration

Planting of wetland vegetation in littoral 

zone, largely north shore to improve 

fishery, to improve water quality, and 

possibly reduce nutrient levels, stabilize 

bottom, and reduce TSS.

Unknown $10,000 (annually)

Lake Apopka 

removal of gizzard 

shad

Harvest of gizzard shad by commercial 

fishermen removes nutrient from lake, 

reduces recycling of nutrients from 

sediments, reduces sediment 

resuspension, and stabilizes bottom to 

reduce TSS.

Unknown $500,000 (annually)

Source: UOBWG (2007)

cfs = cubic feet per second

FWC = Florida Fish and Wildlife Conservation Commission

LCWA = Lake County Water Authority

SJRWMD = St. Johns River Water Management District

Wetlands can also reduce nutrient loadings to waterbodies from upstream tributaries and runoff sources. 

For example, as a result of discharges from the Main Street water reclamation facility (WRF) and 

Gainesville stormwater, there is an increased nutrient load to Paynes Prairie. There has also been a loss of 

the natural sheetflow in Sweetwater Branch, which shortens the hydroperiod. Both of these actions have 

adversely affected Alachua Sink, located downstream of Sweetwater Branch. The City has proposed to 

remove nutrients from water in Sweetwater Branch with a proposed project to return sheetflow to Paynes 

Prairie and creation of a wetland treatment system that involves (Wetland Solutions, Inc., 2007): 

 Upgrades to the Main Street WRF – chemical alum treatment to reduce TP and mechanical 

equipment upgrades to optimize TN removal

 Construction of Sweetwater Branch enhancement wetland – 122-acre area with a channel 

diversion structure and sediment pond, four cells in two trains, and emergent marsh/open water 

 Construction of a sheetflow distribution channel – 5,000 ft in length, 40-ft bottom width, and 11 

outlet spillways

 Backfilling the Sweetwater Branch Canal – backfill 10,000 ft of existing Sweetwater Branch 

Canal, replant 33 acres with native wetland vegetation, and eliminate direct connection to 

Alachua Sink.

Exhibit 12-7 provides the planning level estimates for the various project components. The OCBWG 

(2008) estimates that the project will result in the point source reductions needed for compliance with the 

Alachua Sink TMDL.
November 2010 12. Benefits of Reducing Nutrient Loads to Lakes and Flowing Waters in Florida 12-19

Exhibit 12-7: Planning Level Estimates for Sweetwater Branch Sheetflow Restoration 

Project

Project Component Construction Mobilization, Contingency, 

Engineering1 Total Capital O&M

Main Street WRF 

Upgrades $1,300,000 $650,000 $1,950,000 $640,000

Sweetwater Branch 

Channel Improvements $831,600 $415,800 $1,247,400 - 

Sweetwater Branch 

Sediment Forebay/ 

Trashrack/Weir Diversion

Structure/Sediment 

Removal

$485,450 $242,725 $728,175 $150,000

Sweetwater Branch 

Constructed Wetland $7,320,600 $3,660,300 $10,980,900 $150,000

Sheetflow Distribution 

Channel $2,898,702 $1,449,351 $4,348,053 $75,000

Sweetwater Branch Canal 

Restoration $657,890 $328,945 $986,835 - 

Public Use Amenities $1,850,000 $925,000 $2,775,000 $150,000

Project Monitoring $14,000 $7,000 $21,000 $100,000

Total $15,538,242 $7,679,121 $23,037,363 $1,265,000

Source: PPPSP (2007)

1. Mobilization, contingency, engineering calculated as 50% of construction cost.

Also, in Florida, regional stormwater treatment facilities or areas combine stormwater BMPs such as wet 

detention ponds with habitat restoration projects such as constructed wetlands. Costs for these treatment 

controls vary based on influent quality, treatment area size, and location. Exhibit 12-8 provides examples 

of regional treatment facilities throughout Florida. 

Exhibit 12-8: Examples of Costs for Regional Stormwater Treatment Facilities in Florida

Project Name Purpose Area treated Project 

Completion Cost Source

Seminole County

Navy Canal RSF Nutrient reduction 820 acres Late 2006 $2.1 million Williams, et al.

(2007)

Cameron Ditch RSF Nutrient reduction 344 acres Early 2007 $1.6 million Williams, et al.

(2007)

Crane Strand 

Stormwater

Treatment Pond

Flood control and 

water quality 2,300 acres Dec-07 $1.53 million Seminole 

County (2007)

Lockhart Smith RSF Flood control and 

water quality - Construction in 2007 $2.33 million Seminole County (2007)

Elder Creek RSF Flood control and 

water quality - Mar-08 $5.46 million Seminole County (2007)

Cassell Creek RSF Flood control and 

water quality 830 acres Sep-10 $2.4 million through FY2010

Seminole 

County (2007)
November 2010 12. Benefits of Reducing Nutrient Loads to Lakes and Flowing Waters in Florida 12-20

Exhibit 12-8: Examples of Costs for Regional Stormwater Treatment Facilities in Florida

Project Name Purpose Area treated Project 

Completion Cost Source

Club II RSF Flood control and 

water quality - Jun-07

$2.97 million 

through 

FY2007; 

$286,332 for 

FY2008.

Seminole 

County (2007)

Midway RSF Flood control and 

water quality - Dec-08 $2.6 million Seminole County (2007)

City of Ocoee

Pioneer Key Regional 

Stormwater Pond Nutrient reduction 124 acres

Funded in 

FY 

2003/2004

$850,000 FL DEP 

(2006)

Sarasota County

Catfish Creek RSF Water quality 810 acres Aug-09 $4 million Sarasota 

County (2008)

Another alternative to constructed wetlands and regional stormwater treatment facilities is the Algal Turf 

Scrubber®. The system uses attached, primarily filamentous algae to capture the energy of sunlight and 

build algal biomass from carbon dioxide. Nutrients such as TN and TP are assimilated into the biomass 

during cellular production. In addition, precipitated pollutants and filtered particles are recovered within 

the algal turf, while ammonia may be volatilized and lost to the atmosphere. A major advantage of the turf 

scrubber is that pollutants are removed from the system on a regular basis through harvesting or recovery 

of biomass. Treatment performance is maintained since there is no build-up of pollutants within the 

system to reduce its effectiveness. 

The Taylor Creek Algal Turf Scrubber® Nutrient Recovery Facility is designed to treat 15 mgd of water 

rerouted from Taylor Creek, a tributary to Lake Okeechobee. The facility is expected to remove 4,000 lbs 

of total phosphorus per year with capital costs of $3.05 million in capital and first year O&M costs of 

$281,610 (SFWMD, 2007). 

In certain lakes, significant phosphorus reductions can be slowed by internal phosphorus loading from 

lake sediments. However, dredging of these sediments removes the legacy phosphorus pollution, resulting 

in more measurable load reductions from controls on point and nonpoint sources. MacTech (2007) 

indicates that dredging unit costs generally range from $1 to $25 per cubic meter of sediment removed for 

uncontaminated sediments and $5 to more than $25 per cubic meter for contaminated sediments. Exhibit 

12-9 provides examples of dredging project and unit costs for lakes in Florida. 

Exhibit 12-9: Dredging Costs for Florida Lakes

Lake Project 

Year

Volume 

Removed 

(m3)

Total Cost

(million $)

Unit Cost 

($/m3) Source

Lake Hancock 2005 19,956,060 $107 to $128 $5.36 to $6.41 Madrid Engineering 

(2005)

Lake 

Hollingsworth 1996-2001 2,217,340 $10.95 $4.94 City of Lakeland (2005)

Lake Panasoffkee 2004 6,116,800 $26 $4.25 MacTech (2007)
November 2010 13. Potential Incremental Benefits of the Numeric Nutrient Criteria 13-1

13. Potential Incremental Benefits of the Numeric Nutrient Criteria

As discussed in Section 12, excessive nutrient concentrations may have a wide range of effects on water 

resources located in the state of Florida. These environmental changes affect environmental services 

valued by humans, such as recreational uses of the waters, and nonuse values. This section describes the 

potential magnitude of the benefits of reducing nutrient concentrations as a result of the rule. The 

magnitude of the potential benefits is quantified by translating these changes into an indicator of overall 

water quality (water quality index) and valuing these improvements. Water quality is calculated for both 

the baseline scenario and post compliance scenario, to calculate the improvements in water quality. This 

change in water quality is then valued in terms of WTP, based on a meta-analysis of valuation studies, for 

the types of uses that are supported by different water quality levels. 16

13.1 Water Quality Index

To link potential water quality changes from reduced nutrient concentrations to effects on human uses and 

support for aquatic and terrestrial species habitat, EPA employed a water quality index (WQI) approach. 

The WQI translates water quality measurements, gathered for multiple parameters that are indicative of 

various aspects of water quality, into a single numerical indicator. The parameters used in formulating the 

WQI are determined based on waterbody type, scientific understanding of ecosystem response to varying 

conditions, and available data. 

Most importantly for the present analysis, the WQI provides the link between specific pollutant levels, as 

reflected in individual parameters within the index, and the presence of aquatic species and suitability for 

particular recreational uses. For this analysis, EPA used an index composed of six parameters to represent 

major stream impairment categories: DO, biochemical oxygen demand (BOD), fecal coliform (FC), TN, 

TP, and total suspended solids (TSS). The WQI value, which is measured on a scale of 0 to 100, reflects 

varying water quality, with 0 for poor quality and 100 for excellent.17

For this analysis, EPA adjusted the index it had previously used in its analysis of the Construction and 

Development (C&D) regulation (U.S. EPA, 2009b) to more closely reflect Florida conditions and to be 

consistent with the nutrient regions and waterbody types used in formulating the criteria. EPA adapted an 

approach used by Cude (2001) to develop region-specific subindex curves for TN and TP and used it to 

develop a series of curves for clear and colored lakes and for the stream criteria regions. Implementing the 

WQI methodology involves three key steps described below: (1) obtaining water quality measurements 

for each parameter included in the WQI; (2) transforming measurements to subindex values expressed on 

a common scale; and (3) weighting and aggregating the individual parameter subindices to obtain an 

overall WQI value that reflects waterbody conditions across the parameters. 

 

16 This analysis follows an approach used by EPA in the Environmental Impact and Benefits Assessment for Final Effluent 

Guidelines and Standards for the Construction and Development Category (U.S. EPA 2009). Technical details involved in the 

meta-analysis discussed in this chapter can be found in EPA (2009) as well as in sources such as Bateman and Jones (2003), 

Johnston et al. (2005, 2006), Shrestha et al. (2007), and Rosenberger and Phipps (2007).

17 Numerous water quality indices have been developed and documented in the literature since the 1960s. A history of these 

studies is outlined in the Environmental Impact and Benefits Assessment for Final Effluent Guidelines and Standards for the 

Construction and Development Category (U.S. EPA, 2009c). 
November 2010 13. Potential Incremental Benefits of the Numeric Nutrient Criteria 13-2

The first step involves gathering water quality data. EPA compiled water quality data for each parameter 

from three sources (in order of priority): FDEP IWR database, United States Geological Survey (USGS) 

National Water Information System, and EPA’s Storage and Retrieval. This step of the methodology is 

described in greater detail in Section 13.1.2. 

The second step in the implementation of the WQI involves the transformation of parameter 

measurements into subindex values that express water quality conditions on a common scale of 0 to 100. 

As mentioned above, EPA developed customized TN and TP curves for this analysis to convert nutrient 

concentrations into the subindex scores for each relevant category of waterbody (i.e., for lakes, the 

waterbody types, clear or colored; for flowing waters, the nutrient regions). The approach involved 

reviewing the distribution of the geometric mean of nutrient concentrations for waterbodies within a given 

region or waterbody type, and based on this distribution and nutrient criteria values, assigning the 

appropriate score. 

In developing the curves, EPA assigned a score of 70 for the criterion and a score of 100 for the 10th 

percentile of the distribution corresponding to the “cleanest” waterbodies within each population. EPA 

assigned the numeric criteria a score of 70 to represent a high level of water quality, but not the pristine 

level of water quality that would correspond to a WQI score of 100. As indicated by the water quality 

ladder (Exhibit 13-6) that relates WQI values to designated uses, a WQI score of 70 corresponds to waters 

that are of sufficient quality to meet all human uses (boating, rough fishing, game fishing, and 

swimming), with the exception of drinking without treatment. Exhibit 13-1 relates graphically the 

distribution of TN and TP concentrations for each relevant category of waterbody and selected threshold 

levels for the corresponding subindices. 

EPA used a similar approach to adjust the DO transformation curve to reflect Florida conditions by tying 

the DO concentrations generally expected in Florida, based on approximate DO concentrations associated 

with waters supporting, partially supporting, or failing to support designated water uses. EPA assumed 

that DO concentrations of 3.1 mg/L or lower correspond to a score of 10, 6.3 mg/L corresponds to 70, and 

8.5 mg/L or greater correspond to 100. For the other parameters, EPA used the curves as specified in the 

C&D analysis [U.S. EPA, 2009b, including TSS curves specific to the three U.S. EPA Level III 

ecoregions intersected by Florida]. 
November 2010 13. Potential Incremental Benefits of the Numeric Nutrient Criteria 13-3

Exhibit 13-1: Distribution of TN and TP Concentrations in Florida Lakes and Flowing waters and 

Corresponding Subindex (SI) Value. 

Exhibit 13-2 presents parameter-specific functions used for transforming water quality data into water 

quality subindices for freshwater waterbodies. The equation parameters for each TSS, TN, and TP 

subindex curves are provided in Exhibit 13-3. Exhibit 13-4 shows the subindex curves for the six 

parameters graphically, including the several curves for TSS, TN, and TP. 

-

1.02.03.04.05.06.07.08.0

TN-Clear

TN-Colored

TP-Clear

TP-Colored

TN-Bone Valley

TN-North Central

TN-Panhandle East

TN-Panhandle West

TN-Peninsula

TP-Bone Valley

TP-North Central

TP-Panhandle East

TP-Panhandle West

TP-Peninsula

Parameter - Ecoregion or Waterbody Type

TN or TP Concentration (mg/L)

Criterion Max

100 70

Min 10th

percentile

Subindex Score 10

[TN] or [TP]

KEY:
November 2010 13. Potential Incremental Benefits of the Numeric Nutrient Criteria 13-4

Exhibit 13-2: Freshwater Water Quality Subindices1

Parameter Concentrations Concentratio

n Unit Subindex

DO

DO saturation ≤100% ≤ 3.1 mg/L 10

DO saturation ≤100% 3.1 < DO < 8.5 mg/L -0.947*DO2 + 27.652*DO - 66.619

DO saturation ≤100% ≥8.5 mg/L 100

100% < DO saturation ≤ 

275% N/A mg/L 100 * exp((DOsat - 100) *-1.197 E-2)

275% < DO saturation N/A mg/L 10

Fecal Coliform

FC ≤ 50 CFU/100 mL 98

FC 50 < FC ≤ 1,600 CFU/100 mL 98 * exp((FC - 50) * -9.9178 E-4)

FC > 1,600 CFU/100 mL 10

Total Nitrogen

TN ≤ TN10 mg/L 10

TN TN10 < TN ≤ TN100 mg/L

a * exp(TN*b); where a and b are 

waterbody type or nutrient regionspecific values

TN > TN100 mg/L 100

Total Phosphorus

TP ≤ TP10 mg/L 10

TP TP10 < TP≤ TP100 mg/L

a * exp(TP*b); where a and b are 

waterbody type or nutrient region--

specific values

TP > TP70 mg/L 100

Total Suspended Solids

TSS ≤ TSS10 mg/L 10

TSS TSS10 < TSS ≤ TSS100 mg/L a * exp(TSS*b); where a and b are EPA 

Level III ecoregion-specific values

TSS > TSS100 mg/L 100

Biochemical Oxygen Demand, 5-day

BOD ≤ 8 mg/L 100 * exp(BOD * -0.1993)

BOD > 8 mg/L 10

BOD = biochemical oxygen demand

DO = dissolved oxygen

FC = fecal coliform

TSS = total suspended solids

1. TSS10, TSS100, TN10, TN100, TP10, and TP100 are region or waterbody type-specific TSS or nutrient 

concentration values that correspond to subindex scores of Val10 and Val100, respectively.

Source: BOD and FC: Cude (2001); TSS, TN, TP, and DO: U.S. EPA, based on Cude's methodology.
November 2010 13. Potential Incremental Benefits of the Numeric Nutrient Criteria 13-5

Exhibit 13-3: TSS, TN, and TP Subindex Curve Parameters

Region/Waterbody Type a b Val100 Val10

TSS

Southeastern Plains 205.300 -0.009 84.659 355.516

Southern Coastal Plain 138.62 -0.0144 22.6564 182.58

Southern Florida Coastal 

Plain 116.95 -0.0405 3.86341 60.7200

TN

Lakes

Clear Lakes 267.9 -2.6843 0.367 1.225 

Colored Lakes 138.26 -0.5359 0.604 4.901 

Flowing waters and Springs

Bone Valley 141.87 -0.4281 0.817 6.196 

North Central 120.47 -0.2903 0.641 8.573 

Panhandle East 119.03 -0.5154 0.338 4.806 

Panhandle West 148.83 -1.1258 0.353 2.398 

Peninsula 126.12 -0.3823 0.607 6.630 

TP

Lakes

Clear Lakes 232.35 -109.07 0.008 0.029 

Colored Lakes 113.14 -9.6029 0.013 0.253 

Flowing waters and Springs

Bone Valley 114.02 -0.9957 0.132 2.444 

North Central 105.81 -1.377 0.041 1.713 

Panhandle East 102.75 -2.132 0.013 1.093 

Panhandle West 104.31 -6.6485 0.006 0.353 

Peninsula 110.05 -3.7706 0.025 0.636 

1. “a” and “b” are ecoregion specific values that are used in the TSS, TN, and TP subindex equations. 
November 2010 13. Potential Incremental Benefits of the Numeric Nutrient Criteria 13-6

Exhibit 13-4: Subindex Curves for the 6 WQI Parameters.

The final step in implementing the WQI involves combining the individual parameter subindices into a 

single WQI value that reflects the overall water quality across the parameters. Following McClelland’s 

(1974) approach, EPA calculated the overall WQI for a given reach using a weighted geometric mean 

function: 

∏=

=

n

i

Wi WQIr Qi

1

 (Eq. 13-1) 

Where:

WQIr = the multiplicative water quality index (from 0 to 100) for reach r 

0

10

20

30

40

50

60

70

80

90

100

0 1 2 3 4 5 6 7 8 9 10

Dissolved Oxygen (mg/L)

Subindex Value

DO (DO saturation less or equal to 100%)

0

10

20

30

40

50

60

70

80

90

100

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Fecal Coliform (Colony Forming Units/100 ml)

Subindex Value

Fecal Coliform

0

10

20

30

40

50

60

70

80

90

100

0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00

Total Nitrogen (mg/L)

Subindex Score

Clear Lakes Colored Lakes Bone Valley North Central

Panhandle East Panhandle West Peninsula

0

10

20

30

40

50

60

70

80

90

100

0.00 0.50 1.00 1.50 2.00 2.50

Total Phosphorus (mg/L)

Subindex Score

Clear Lakes Colored Lakes Bone Valley North Central

Panhandle East Panhandle West Peninsula

0

10

20

30

40

50

60

70

80

90

100

0 50 100 150 200 250 300 350 400

Total Suspended Solids (mg/L)

Subindex Score

Southeastern Plain Southern Coastal Plain Southern Florida Coastal Plain

0

10

20

30

40

50

60

70

80

90

100

0 1 2 3 4 5 6 7 8 9 10

Biochemical Oxygen Demand, 5-days (mg/L)

Subindex Value

BOD
November 2010 13. Potential Incremental Benefits of the Numeric Nutrient Criteria 13-7

Qi = the water quality subindex measure for parameter i

Wi = the weight of the i-th parameter

n = the number of parameters 

Exhibit 13-5 provides the weights used in aggregating the individual subindex values for the six 

parameters into the overall WQI. EPA (2009b) revised the weights originally developed by McClelland 

(1974) by redistributing the weights to the six parameters retained in the EPA WQI so that the ratio 

among the parameters is maintained and the weights sum to 1. 

Exhibit 13-5: Original and Revised Weights for Freshwater WQI Parameters

Parameters Weights 

DO (% saturation and mg/L) 0.24

Fecal coliform (colony forming units/100 mL) 0.22

Biochemical oxygen demand, 5-day (mg/L) 0.15

Total nitrogen (mg/L) 0.14

Total phosphorus (mg/L) 0.14

Total suspended solids (mg/L) 0.11

Total 1.00

Source: U.S. EPA (2009b)

13.1.1 Relation between WQI and Suitability for Human Uses

Once an overall WQI value is calculated, it can be related to suitability for potential uses. Vaughan (1986) 

developed a water quality ladder (WQL) that can be used to indicate whether water quality is suitable for 

various human uses (i.e., boating, rough fishing, game fishing, swimming, and drinking without 

treatment). Vaughan identified “minimally acceptable parameter concentration levels” for each of these 

five potential uses. Water quality is deemed acceptable for each use if none of the six subindex values 

exceeds the threshold concentration levels. EPA converted Vaughan’s scale of zero to 10 to a WQI scale 

of zero to 100 to classify water quality based on its suitability for potential uses. Exhibit 13-6 presents 

water use classifications and the corresponding WQL and WQI values.

Exhibit 13-6: Water Quality Classifications

Water Quality Classification WQL Value1 WQI Value2

Drinking without treatment 9.5 95

Swimming 7.0 70

Game fishing 5.0 50

Rough fishing 4.5 45

Boating 2.5 25

1. Source: Vaughan (1986).

2. Equals Vaughan’s (1986) WQL value times 10. 

13.1.2 Baseline Ambient Water Quality 

For lakes and flowing waters, EPA used the following data sources to obtain ambient concentrations for 

the six parameters included in the WQI:

 FDEP IWR database (Run 40) (all parameters). 

 USGS National Water Information System (NWIS) (FC, DO, and BOD concentrations for 

WBIDs for which the IWR does not contain data)
November 2010 13. Potential Incremental Benefits of the Numeric Nutrient Criteria 13-8

 EPA’s Storage and Retrieval (STORET) (additional FC counts and BOD data (USEPA 2008b) 

for WBIDs for which NWIS does not contain data). 

The IWR database contains baseline data for at least one WQI parameter for 2,048 of the 5,211 

freshwater WBIDs in the state. While the IWR data includes TN, TP, and TSS values for most of these 

2,048 WBIDs, there are only limited data for the other three WQI parameters.18 For example, FC data are 

only available for two WBIDs. In cases where FC, DO, or BOD data are not available for a given WBID 

from FDEP IWR, EPA used the average of ambient concentrations reported by NWIS or STORET for 

waterbodies within the same 6-digit HUC level watershed to impute missing values to the WBID.19 This 

approach assumes that waterbodies located in the same watershed generally share similar characteristics. 

Using this imputation approach, EPA was able to compile the necessary water quality data for the WQIbased benefits analysis for 2,153 freshwater WBIDs in the state, including 313 of the 325 incrementally 

impaired WBIDs (representing approximately 96% of all incremental impaired WBIDs in the state). 

EPA calculated the WQI separately for lakes and flowing waters for several reasons. The first is that the 

fundamental differences between lakes and flowing waters may make it difficult to compare 

improvements in the different types of waterbodies. Flowing waters tend to be shallow, whereas lakes are 

relatively still and deep. In addition, the two waterbody categories differ in how their size is expressed --

lakes are reported based on area, whereas flowing waters are reported based on length. Exhibit 13-7

shows the distribution of flowing waters by WQI value for the baseline scenario (existing conditions). 

Exhibit 13-8 contains the baseline distribution of lakes by WQI value. 

As shown below, under the baseline scenario the majority of flowing waters and springs have high water

quality, with approximately 65% being classified as swimmable (WQI > 70). In comparison, the majority 

of lakes have low water quality under the baseline scenario, with approximately 52% of lakes being

classified as suitable for boating, but not suitable for game fishing or swimming (25<WQI<50). This is to 

be expected because the stillness of lakes often results in eutrophication being a larger problem than in 

flowing waters where nutrients do not as readily accumulate in one place. 

Exhibit 13-7: Estimated Percentage of Freshwater Flowing Water and Spring Miles in 

Florida by WQI Classifications: Baseline Scenario

Baseline WQ Total Miles Percent of Total

WQI<25 0 0.00%

25≤WQI<50 961 9.70%

50<WQI<70 2,466 24.90%

70<WQI 6,475 65.39%

Total Miles1 9,901 100.00%

1. Includes 1,280 of 34,027 flowing water and spring WBIDs for which data for all six WQI parameters is 

available or can be imputed from other sources.

 

18 Average concentrations over a 5-year period were generally used for each WQI parameter, with the exception of TN and TP 

for which EPA used the average of annual geometric means, consistent with the criteria specifications. In the case of 

incrementally impaired WBIDs, EPA used the average of geometric means for years during which the annual geometric means 

exceed the criteria.

19 EPA did not impute TN or TP in cases where the FL IWR database did not provide sufficient information because EPA 

assumed that where data are insufficient to assess impairment, the water is not impaired (see Section 4.2). 
November 2010 13. Potential Incremental Benefits of the Numeric Nutrient Criteria 13-9

Exhibit 13-8: Estimated Percentage of Lake Area in Florida by WQI Classification: 

Baseline Scenario

Baseline WQ Total Acres Percent of Total

WQI<25 147 0.01%

25≤WQI<50 623,815 52.23%

50<WQI<70 319,344 26.74%

70<WQI 251,125 21.02%

Total Area1 1,194,431 100.00%

1. Includes 873 of 1,310 lake WBIDs for which data for all six WQI parameters is available or can be 

imputed from other sources.

13.1.3 Estimated Changes in Water Quality from Attaining Criteria

To estimate benefits of water quality improvements associated with the criteria, EPA calculated the postcompliance WQI assuming that all incrementally impaired waterbodies meet the numeric nutrient 

criterion, and there are no water quality improvements in any waters that are not incrementally impaired 

under the rule. Although these nutrient reductions may also change the levels of other water quality 

parameters, such as DO, that are included in the WQI, these ancillary improvements are not reflected in 

the change in index value. The potential effects of considering changes in DO are discussed in Appendix 

F. 

Rather than establishing criteria for TN in springs, the rule establishes criteria for nitrate-nitrite

concentrations (NO2 + NO3) in these waterbodies. To calculate the benefits associated with attaining these 

standards, EPA calculated the proportion of NO2+NO3 that comprises TN for each incrementally impaired 

spring WBID. EPA then calculated the post-compliance TN concentrations for each incrementally 

impaired WBID by reducing the NO2+NO3 concentrations to 0.35 mg/L (the EPA criterion) and assuming 

the ratio of NO2+NO3 to TN remains unchanged. 

The difference in WQI (hereafter denoted as ΔWQI) between baseline conditions and compliance with 

the numeric TN and TP criteria is a measure of the change in water quality that may be attributable to the 

rule. To monetize benefits of the regulation, EPA calculated the improvement in water quality for all 

incrementally impaired waterbodies where ΔWQI is greater than de minimus (0.01 WQI units). 

As shown in Exhibit 13-9 and Exhibit 13-10, a total of 1,502 miles of flowing waters and springs and 

150,438 acres of lake area, respectively, are potentially incrementally impaired under the numeric criteria 

and thus may attain higher water quality by coming into compliance with the criteria. These miles account 

for 6.1% of all freshwater stream and spring miles in the state and 1.5% of all water area in the state (all 

lake, beach, coastal, and estuary area). A total of 325 individual WBIDs may show improved water 

quality; however EPA was able to calculate possible improvements for 313 incrementally impaired 

WBIDs (96% of impaired WBIDs) where data for all six water quality parameters are available. 
November 2010 13. Potential Incremental Benefits of the Numeric Nutrient Criteria 13-10

Exhibit 13-9: Potential Water Quality Improvements in Flowing waters and Springs

Change in WQI No. of WBIDs 

Improved

Total Miles 

Improved

Percent of Total Miles 

in Analysis

Percent of Total Water 

Miles in State1

0.01 < ΔWQI < 1.0 35 321 3.24% 1.31%

1.0 < ΔWQI < 5.0 84 897 9.06% 3.65%

5.0 < ΔWQI 47 284 2.87% 1.15%

Total 166 1,502 15.17% 6.10%

WBID = waterbody identification

WQI = water quality index

1. Percentage taken out of total river, blackwater, and spring miles in Florida (24,603 miles).

Exhibit 13-10: Potential Water Quality Improvements in Lakes

Change in WQI No. of WBIDs 

Improved

Acres 

Improved

Percent of Total Area 

in Analysis

Percent of Total Water 

Area in State1

0.01 < ΔWQI < 1.0 6 20,262 1.70% 0.20%

1.0 < ΔWQI < 5.0 40 75,458 6.32% 0.74%

5.0 < ΔWQI 101 54,717 4.58% 0.54%

Total 147 150,438 12.59% 1.48%

WBID = waterbody identification

WQI = water quality index

1. Water area includes lake, coastal, beach, and estuary area (10,179,200 acres).

13.2 Willingness to Pay for Water Quality Improvements 

To estimate nonmarket benefits of water quality improvements resulting from the rule, EPA used a 

benefits transfer function based on meta-analysis results presented in EPA (2009b). The general approach 

follows standard methods used by EPA (2009b), Johnston et al. (2005) and Shrestha et al. (2007), among 

many others (see Rosenberger and Phipps, 2007). This function provides a means of forecasting WTP

based on estimated values for model variables chosen to represent potential water quality improvements. 

The meta-analysis results imply a benefit function of the following general form: 

ln(WTP) = intercept +∑ nt(coefficie )(Independ Variableent Values ) i i (Eq. 13-2) 

Here, ln(WTP) is the dependent variable in the meta-analysis—the natural log of WTP for water quality 

improvements. The metadata include independent variables characterizing specific details of the resources 

valued, such as the baseline resource conditions; the extent of resource improvements and whether they 

occur in estuarine or freshwater; the geographic region and scale of resource improvements (e.g., the 

number of waterbodies); resource characteristics (e.g., baseline conditions, the extent of water quality 

change, and ecological services affected by resource improvements); characteristics of surveyed 

populations (e.g., users, nonusers); and other specific details of each study. Exhibit 13-11 provides the 

estimated regression equation intercept (5.71), variable coefficients (coefficienti), and the corresponding 

independent variable names. EPA (2009b) provides detail on the metadata, model specification, and 

justification for the functional form.

EPA assigned a value to each model variable corresponding with theory, characteristics of the water 

resources, and sites affected by the regulation and the policy context. Exhibit 13-11 presents a complete 

list of assigned variable values. 

EPA followed Johnston et al. (2006) in assigning values for methodological attributes (i.e., variables 

characterizing the study methodology used in the original source studies), which are set at mean values 
November 2010 13. Potential Incremental Benefits of the Numeric Nutrient Criteria 13-11

from the metadata except in cases where theoretical considerations dictate alternative specifications. This 

approach follows general guidance from Bergstrom and Taylor (2006) that meta-analysis benefit transfer 

should incorporate theoretical expectations and structures, at least in a weak form. In this instance, three 

of the methodology variables, discrete, WQI_study, and outlier_bids are all included with an assigned 

value of one. Year_index is given the value of 9.68, which corresponds to the mean year that the studies 

were conducted, 2002. Nonparam is set to zero because most studies included in metadata used 

parametric methods to estimate WTP values. Other study and methodology variables (volunt, mail, 

lump_sum, non_reviewed, median_WTP) are assigned a zero value. 

EPA used state-specific median household income, as provided by the U.S. Census Bureau’s 2006 

American Communities Survey (U.S. Census Bureau 2006a), to assign a value for the income variable 

(income) for all full time residents in Florida. The annual income for seasonal residents is taken from 

Smith and House (2006). EPA used the Consumer Price Index to adjust the value from the 2006 survey 

and the 2006 study to 2010 dollars. The variable nonusers was set to zero because water quality 

improvements resulting from nutrient reductions would benefit both users and nonusers of the affected 

resources (See Section Exhibit 13-11). 

The regulation is expected to affect water quality at the state level because the impaired waterbodies are 

located throughout the entire state. The dummy variable denoting multiple regions (mr) is set to zero 

because the water quality improvement will only be in the state of Florida. The Mountain Plain regional 

dummy variable (mp) is also set to zero because the magnitude of the regional effect suggests that 

spurious or otherwise unexplained effects (e.g., the effect of specific researchers who appear more than 

once in the data) may drive their overall magnitude. EPA (2009b) provides more detail on regression 

results.

To account for the regional scale of the water quality effect in fresh waterbodies resulting from the 

regulation, the variable regional_fresh is assigned a value of one. Other variables relating to waterbody 

type (i.e., single_lake, single_river, salt_pond, multiple_river, num_riv_pond) are set to zero. 

Water quality improvements resulting from the regulation are likely to enhance a variety of water 

resource uses, including fishing, swimming, and boating. Therefore, variables denoting multiple uses 

(allmult) and recreational fishing (fish_use) are assigned a value of one, while the variable denoting 

nonspecified uses (nonspec) is set to zero. However, the variable fishplus is given a value of zero because 

it is unlikely that the regulation will cause more than a 50% increase in the fish population. Baseline 

water quality (baseline) and change in water quality (quality_ch) are assigned WBID-specific values as 

described in Sections 13.1.2 and 13.1.3. For a broader discussion of issues involved in the specification of 

variable levels for meta-analysis benefit transfer, see Johnston et al. (2005, 2006), among others. 

Exhibit 13-11: Independent Variable Assignments

Variable Coefficient Assigned 

Value Explanation

Study and Methodology Variables

intercept 5.7109 N/A N/A

year_index -0.08043 9.68 Set to 9.68 to reflect the mean year that the studies in the data 

set were conducted. 

discrete -0.1248 1 

Set to one to reflect survey efforts that employed discrete 

choice elicitation methods, which are preferred over other 

approaches, such as open-ended and payment card methods.
November 2010 13. Potential Incremental Benefits of the Numeric Nutrient Criteria 13-12

Exhibit 13-11: Independent Variable Assignments

Variable Coefficient Assigned 

Value Explanation

volunt -1.3233 0 

Set to zero because hypothetical voluntary payment 

mechanisms are not even potentially incentive compatible 

(Mitchell and Carson 1989).

mail -0.2013 0 Set to zero because mail surveys may be of less quality than 

in-person interviews.

lump_sum 0.5569 0 Set to zero because the policy option will be paid for over a 

period of years.

WQI -0.3275 1 Set to one because of the methodological use of the WQI in 

the meta-analysis.

nonparam -0.6698 0 Set to zero because most studies used in the meta analysis 

used regression analysis to calculate willingness to pay values.

non_reviewed -0.2718 0 Set to zero to reflect a preference for studies published in 

peer-reviewed journals.

median_WTP -0.5358 0 

Set to zero because only average or mean WTP values in 

combination with the number of affected households will 

mathematically yield total benefits if the distribution of WTP 

is not perfectly symmetrical.

outlier_bids -0.8837 1 

Set to one because survey data that exclude such responses 

are preferable; outlier bids are often excluded from the 

analysis of stated preference data because these bids (often 

identified as greater than a certain percentage of a 

respondent’s income) may indicate that 

a respondent did not consider his or her budget constraints 

and or supplementary goods.

Surveyed Population

income 0.0000027 Varies

Median annual household income data from the 2006 

American Communities Survey and Smith et al (2006); 

median household income values assigned separately for full 

time state residents and part time seasonal residents (U.S. 

Census Bureau 2006a and Smith ea al. 2006).

nonusers -0.4036 0 

Set to zero in order to estimate the total value for aquatic 

habitat improvements, including both use and nonuse values; 

for nonuser population, the total value of water resource 

improvements includes nonuse values only (Freeman 2003). 

Waterbody Type Variables

single_river -0.4279 0

The criteria are only for fresh waterbodies, therefore 

regional_fresh is set to one because multiple fresh waterbodies

within the state will be affected by the regulation. 

single_lake -0.06316 0

multiple_river -1.4752 0

regional_fresh 0.1588 1

salt_pond 0.9849 0

Geographic Region and Scale Variables

num_riv_

pond 0.1173 0 

Indicates the number of rivers or salt ponds affected by a 

policy, and is set to zero because the criteria affect the entire 

state; this variable assignment is constant across study 

regions.

mr -0.8846 0 Regional variables are omitted from the predictive portion of 
November 2010 13. Potential Incremental Benefits of the Numeric Nutrient Criteria 13-13

Exhibit 13-11: Independent Variable Assignments

Variable Coefficient Assigned 

Value Explanation

mp 1.6337 0 

the analysis (i.e., set to zero) because the regression results 

suggest that these variables may be picking spurious or other 

unexplained effects (e.g., author’s effect).

Resource Improvement Variables

allmult -0.3728 1 Set to one because multiple species may benefit from water 

quality improvements

nonspec -0.4042 0 Set to zero because multiple species may benefit from water 

quality improvements. 

lnquality_ch 0.4065 Varies Set to the natural log of the change in the WQI for a given 

WBID.

fish_use -0.3317 1 Set to one because a variety of aquatic species may benefit , 

therefore enhancing recreational fishing opportunities.

fishplus 0.4432 0 Set to zero because a fish population change of 50% or 

greater is unlikely.

lnbase 0.02610 Varies Set to the natural log of the base WQI for a given WBID

N/A means not applicable 

Using this function, EPA calculated the estimated economic values of water quality improvements by 

WBID. For each WBID, coefficient estimates for each variable, taken from meta-analysis results (Exhibit 

13-11, column 3) are multiplied by the variable levels chosen above (Exhibit 13-11, column 4). The sum 

of these products represents the predicted natural log of WTP (ln_WTP) for a given WBID, as indicated 

by Equation 13-2. The final step uses a standard formula to transform this predicted natural log into the 

desired WTP estimate. This formula is given by: 

WTP = exp(ln_WTP + σe2/2) (Eq. 13-3) 

Where: 

exp(∙) = the exponential operator 

ln_WTP = the predicted natural log of WTP for WQ improvements in a given WBID

σe

2

 = the model residual variance (0.1876) taken from EPA (2009b).

The total WTP regression model presented above can be used to predict WTP for each of the studies in 

the database; however, estimates derived from regression models are subject to some degree of error and 

uncertainty. To better characterize the uncertainty or error bounds around predicted WTP, EPA used a 

procedure described by Krinsky and Robb (1986). The procedure involves sampling the variance–

covariance matrix of the estimated coefficients, which is a standard output of the statistical package used 

to estimate the meta-analysis model. WTP values are then calculated for each drawing from the variance–

covariance matrix and an empirical distribution of WTP values is constructed. By varying the number of 

drawings, it is possible to generate an empirical distribution with a desired degree of accuracy (Krinsky 

and Robb, 1986). The low and high estimate of WTP values is then identified based on the 10th and 90th 

percentile of WTP values from the empirical distribution. These bounds may help decision-makers 

understand the uncertainty associated with the benefit results. 

EPA used the Krinsky and Robb (1986) procedure to estimate the 10th, 50th, and 90th percentiles of total 

WTP for both full time and part time seasonal residents, based on the results of the total WTP regression 
November 2010 13. Potential Incremental Benefits of the Numeric Nutrient Criteria 13-14

model. It is estimated that seasonal residents will live in the state for approximately 4 months of the year, 

therefore household WTP value for seasonal residents were weighted by 25%. WTP to pay is calculated 

separately for both flowing waters and lakes, because of the different size units for the two categories 

(i.e., miles and acres). Exhibit 13-12 presents the results of these calculations. Although the confidence 

limits for WTP estimates related to the covariance matrix of meta-analysis parameter estimates can be 

estimated, these limits do not assess the sensitivity of results to changes in meta-regression model 

assumptions or specifications (cf. Johnston et al., 2005; 2006) or assumptions implied in benefit 

aggregation (cf. Loomis, 1996; Loomis et al., 2000; Bateman et al., 2006). As noted above, however, a 

number of assumptions and specifications lead to conservative benefit estimates.

Exhibit 13-12: Estimated Average Annual Household WTP for Water Quality 

Improvement in Florida (2010$)

State Resident Type

Flowing waters Lakes

10th 

Percentile

50th 

Percentile

90th 

Percentile

10th 

Percentile

50th 

Percentile

90th 

Percentile

Full Time Resident $1.52 $2.94 $4.71 $0.49 $0.89 $1.32

Part Time Winter Resident $0.39 $0.78 $1.28 $0.13 $0.24 $0.38

WTP = willingness to pay

As shown in Exhibit 13-9 and Exhibit 13-10, a total of 15.2% of water miles in the analysis (6.1% water 

miles in the state) and 12.6% of water area in the analysis (1.5% of all water area in the state) may 

improve as a result of the numeric nutrient criteria. Average annual household WTP for full time residents 

for these improvements may be approximately $2.94 (mid-point estimate) for improvements in flowing 

waters and $0.89 (mid-midpoint estimate) for improvements in lakes. Part time residents have smaller 

average annual household WTP, with mid-point estimates ranging from $0.24 per household for 

improvements in lakes to $0.78 for improvements in flowing waters and springs. 

13.3 Estimating Total WTP for Water Quality Improvements

To calculate WBID-level WTP, EPA estimated mean per-household WTP for both full-time and part-time 

residents and both lakes and flowing waters by WBID, and then multiplied by the number of households 

in each category in 2006 and the percentage of miles or area that comprise a given WBID. EPA calculated 

the number of full time households in the state by dividing the population estimates by the average 

number of people per household (U.S. Census Bureau, 2006a; 2006b), and the number of part-time 

households by dividing the number of seasonal residents from Smith and House (2006) by the average 

number of people per household (U.S. Census Bureau, 2006b). The total WTP equation for each reach is 

provided below (Equation 13-4): 

TWTP WQIWTP WQI),( StateHH PercentMiles) WBID = baseline ×∆ × (Eq. 13-4) 

Where:

TWTPWBID = the WBID-level welfare change from improved water quality 

WTP = the estimated WTP for water quality improvement for a given WBID based on 

baseline WQI (WQI baseline) and the expected change in water quality under the 

post-compliance scenario (ΔWQI)

StateHH = the number of full-time or seasonal households in Florida
November 2010 13. Potential Incremental Benefits of the Numeric Nutrient Criteria 13-15

PercentMiles = the percentage of total miles (for flowing water) or total miles squared (for lakes) 

in the state of Florida that are comprised of a given WBID. 

Finally, EPA aggregated WBID-level benefits to the state level for full time and part time households. As 

presented in Exhibit 13-13, full time resident annual benefits range from $6.48 million (mid-point 

estimate) for improvements in lakes to $21.31 million (mid-point estimate) for improvements in flowing 

waters. Seasonal resident annual benefits are much smaller, with mid-point estimates of $0.26 and $0.08 

million for improvements in flowing waters and lakes, respectively. Total state benefits are approximately 

$28.12 million per year ($21.56 million of improvements in flowing waters and $6.56 million for 

improvements in lakes). 

Exhibit 13-13: Potential Annual Benefits for Water Quality Improvement to Freshwater 

Flowing Waters and Lakes in Florida (Millions of 2010$ per year)

State Resident 

Type

Flowing waters Lakes

10th 

Percentile

50th 

Percentile

90th 

Percentile

10th 

Percentile

50th 

Percentile

90th 

Percentile

Full Time Residents $11.04 $21.31 $34.14 $3.58 $6.48 $10.02

Part Time Winter 

Residents $0.13 $0.26 $0.42 $0.04 $0.08 $0.12

Total $11.17 $21.56 $34.56 $3.62 $6.56 $10.14

Note that a portion of these benefits would be attributable to baseline controls for urban stormwater that 

are not yet fully implemented but would result in reductions in nutrient concentrations. It is not possible 

to identify the water quality that would result after full implementation of such controls. Thus, the portion 

of benefits attributable to controls not included in the cost analysis (because they are part of the baseline 

and required in the absence of the rule) is uncertain. 

13.4 Uncertainty and Limitations

A number of issues are common to all benefit transfers. Benefit transfer involves adapting research 

conducted for another purpose in the available literature to address the policy questions at hand. Because 

benefits analysis of environmental regulations rarely affords enough time to develop original stated 

preference surveys that are specific to the policy effects, benefit transfer is often the only option to inform 

a policy decision. As a result, they are nearly universal in benefit-cost analyses (Smith et al., 2002). 

Benefit transfers are by definition characterized by a difference between the context in which resource 

values are estimated and that in which benefit estimates are desired (Rosenberger and Phipps, 2007). The 

ability of meta-analysis to adjust for the influence of study, economic, and resource characteristics on 

WTP can minimize, but not eliminate, potential biases (Smith et al., 2002; Rosenberger and Stanley, 

2006; Rosenberger and Phipps, 2007). As is typical in applied benefit transfers, the meta-analysis model 

used in this analysis provides an imperfect match to the context in which values are desired. Therefore, 

some beneficial effects may not be accounted for while others may be overestimated. 

Some related and additional limitations inherent to the meta-analysis model and the subsequent benefit 

transfer include the numerous uncertainties and associated assumptions required to aggregate WTP across 

spatial jurisdictions, as detailed by Loomis (1996), Loomis et al. (2000) and Bateman et al. (2006), among 

others. While these uncertainties are well known, the literature does not agree on appropriate, 

standardized guidance for benefit aggregations, and applied benefit-cost analysis almost universally 

requires simplifying assumptions in order to generate defensible welfare aggregations. In an ideal context, 
November 2010 13. Potential Incremental Benefits of the Numeric Nutrient Criteria 13-16

analysts would have information necessary to estimate spatially referenced distance decay relationships 

for all changes resulting from policies under consideration (cf. Bateman et al., 2006). However, even the 

most advanced literature provides only simple illustrations of such issues, and none methodologically 

sufficient to support regulatory analysis. 

In analyzing benefits of the rule, EPA estimated benefits from nutrient reductions to Florida households 

only. Although residents of other states may hold values for water resources outside of their home state, if 

such resources have personal, regional, or national significance, EPA did not have sufficient information 

to estimate WTP for water quality improvements in Florida for out of state residents. As a result, the 

population considered in the benefits analysis of the rule does not represent all the households that are 

likely to hold values for water resources in the state of Florida. Even if per household WTP for out-ofstate residents are small they can be substantial in the aggregate if these values are held by a substantial 

fraction of the population. 

Some resource valuation studies have found that respondents in the typical contingent market situation 

may overstate their WTP compared to their likely behavior in a real-world situation. However, the 

magnitude of hypothetical bias on the estimated WTP is uncertain. Following standard benefit transfer 

approaches, including Meta-analysis transfers, this analysis reflects the assumption that each source study 

provides a valid, unbiased estimate of the welfare measure under consideration (cf. Moeltner et al., 2007; 

Rosenberger and Phipps, 2007). To minimize potential hypothetical bias, EPA set independent variable 

values to reflect best benefit transfer practices. 

The estimation of WTP may be sensitive to differences in the environmental water quality measures. 

Studies that did not use the WQI were mapped to the WQI so a comparison could be made across studies. 

The dummy variable (WQI) captures the effect of a study using (WQI=1) or not using the WQI (WQI=0). 

It was found that studies that did not use the WQI had lower WTP values. This may indicate that there 

may have been some systematic biases in the mapping of studies that did not use the WQI. In analyzing 

the benefits of this regulation, EPA set the WQI to one to reduce uncertainty in WTP estimates associated 

with studies that did not include WQI as a native survey instrument. EPA (2009b) provides a detailed 

discussion of water quality measures used in the original studies included in the meta-analysis. 

Transfer error may occur when benefit estimates from a study site are adopted to forecast the benefits of a 

policy site. Rosenberger and Stanley (2006) define transfer error as the difference between the transferred 

and actual, generally unknown, value. While meta-analysis is fairly accurate when estimating benefit 

function, transfer error may be a problem in cases where the sample size is small. While meta-analyses 

have been shown to outperform other function-based transfer methods in many cases, this result is not 

universal (Shrestha et al., 2007). This notwithstanding, results reviewed by Rosenberger and Phipps 

(2007) are “very promising” for the performance of meta-analytic benefit transfers relative to alternative 

transfer methods.

Additional limitations and uncertainties are associated with the use of the WQI to link water quality 

changes from reduced nutrient discharges to effects on human uses and support for aquatic and terrestrial 

species habitat. These include, for example, that the estimated changes in WQI reflect only water quality 

improvements resulting directly from reductions in nutrient loadings but do not include potential 

improvements in water quality indicators indirectly associated with nutrient loadings (e.g., DO). This 

omission is likely to result in the underestimation of the expected water quality changes resulting from the 

rule because the combined impact of several pollutants on ambient water quality is likely to be greater 

than the sum of the individual impacts of reducing concentrations of nutrients. Appendix D provides a 

comparative analysis that considers improvements in DO. 
November 2010 13. Potential Incremental Benefits of the Numeric Nutrient Criteria 13-17

Benefits attributed to improvements in springs are likely to be over estimates because of the length of 

time it may take for springs to improve as a result of the nutrient criteria. Due to the high porosity of the 

karst geology in the area, the Floridian Aquifer has highly accessible storage, meaning that flows to 

springs are only weakly responsive to short-term weather patterns, and it takes a long time for water from 

the massive aquifer to reach the springs. This implies that changes in nutrient loading may take decades to 

affect water quality in the springs. The WTP values above are all annual present values and have been 

calculated under the assumption that reductions in nutrient loadings will result in immediate 

improvements in water quality. Because the improvements in springs may take decades, these benefits are 

likely overstated because empirical evidence suggests that people value immediate or near-term benefits 

at higher levels than those acquired in the distant future. However, because the proportion of benefits 

resulting from water quality improvements in springs is so small (approximately 2% of total benefits), it 

is likely this overestimation has a very small impact on total benefits. 

In addition, there is uncertainly surrounding the water quality measurements used to calculate the WQI 

values. Specifically, the use of 6-digit HUC averages may over or underestimate the values of a given 

WQI parameter for a particular WBID, as these averages are based on data from many waterbodies within 

the HUC, as water quality may very greatly between waterbodies within the fairly large 6-digit HUC 

level. There is also additional uncertainty surrounding all water quality data because of possible sampling 

or human reporting error. 

Finally, the methodology used to translate instream sediment and nutrient concentrations into sub-index 

scores employs nonlinear transformation curves. Water quality changes that fall outside of the sensitive 

part of the transformation curve (i.e., above/below the upper/lower bounds) yield no benefit in the 

analysis.
November 2010 14. References 14-1

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November 2010 Appendix A. Incremental Costs of EPA’s Criteria Compared to FDEP’s 2009 Draft Criteria A-1

Appendix A. P otential Inc remental C os ts As s oc iated with E PA’s R ule 

C ompared to F DE P ’s 2009 Draft Numeric Nutrient C riteria

This Appendix provides an estimate of the potential incremental costs of attaining EPA’s numeric nutrient 

criteria compared to a baseline of the FDEP’s July 2009 draft nutrient criteria. 

A.1 Incrementally Impaired Waters

EPA used the same data and method described in Section 6.1 and 6.2 to identify potential incremental 

impairments under the FDEP’s July 2009 draft numeric nutrient criteria. The one exception to this method 

relates to evaluation of FDEP’s 2009 draft nitrate-nitrite criterion for clear streams and springs. This 

criterion is based on a monthly median that only applies in months when the median color is less than 40 

Pt-Co. Due to limited color data corresponding to the months for which nutrient data are available, EPA 

did not identify springs that would be impaired under the FDEP’s draft July 2009 criteria. 

Exhibit A-1 summarizes the potential incremental impairments under based on FDEP’s July 2009 draft 

numeric nutrient criteria. 

Exhibit A-1. Potential Incrementally Impaired Waters under FDEP July 2009 Draft 

Numeric Nutrient Criteria

Category Number of WBIDs

Lake Stream1 Spring Total

Total in State 1,310 3,901 126 5,337

Not Listed/Covered by TMDL2 1,099 3,608 119 4,826

Nutrient Data in IWR Run 403 878 1,273 72 2,223

Sufficient Data Available4 655 930 -- 1,585

Potentially Exceeding Criteria5 114 111 -- 225

IWR = Impaired Waters Rule

TMDL = total maximum daily load

WBID = waterbody identification

1. Includes blackwater.

2. As reported in TMDL documents and FDEP (2009c).

3. Data within last 5 years meeting data quality requirements.

4. Annual geometric means based on at least 4 samples with one sample from May to September and one 

sample from October to April in a given year. For monthly geometric mean, there are no data requirements.

5. Based on annual geometric mean exceeding the applicable TN or TP criterion more than once in a three 

year period.

Of the 225 waters shown in Exhibit A-1, 220 would also be impaired based on EPA’s numeric nutrient 

criteria. Thus, the incremental number of impairments associated with EPA’s rule that are over and above 

those that would be associated with FDEP’s July 2009 draft criteria as the baseline is 325 – 220 = 105 

(the difference between those shown in Exhibit 6-1 and the waters that would be impaired under the 

FDEP draft criteria as well as under EPA’s rule).

Exhibit A-2 shows the land use surrounding these waters based on the method described in Section 6.4 of 

this report (acreage within 10-digit HUCs that include at least 10% of incrementally impaired waters that 

are not also included in the watersheds of waters already impaired under the narrative criterion). 
November 2010 Appendix A. Incremental Costs of EPA’s Criteria Compared to FDEP’s 2009 Draft Criteria A-2

Exhibit A-2. Summary of Land Use for Potential Incrementally Impaired Watersheds: 

EPA Rule Compared to FDEP July 2009 Draft Numeric Nutrient Criteria1

Land Use Category Land Use Area Percent of Total

Forest 1,114,155 38%

Wetlands 713,525 24%

Agriculture 736,024 25%

Urban 206,513 7%

Other 51,949 2%

Water 64,530 2%

Industrial 14,493 <1%

Transportation Corridors 13,259 <1%

Communications and Utilities 9,480 <1%

Total 2,923,929 100%

Note: Detail may not add to total due to independent rounding.

1. Represents 10-digit HUCs containing at least 10% of the 225 waters that are impaired under FDEP’s July 

2009 draft numeric nutrient criteria.

A.2 Municipal and Industrial Dischargers

Both FDEP’s 2009 draft criteria and EPA’s nutrient criteria are at or below the target treatment levels for 

TN and TP for municipal wastewater treatment plants (WWTPs) and industrial dischargers. Based on the 

methods described in Sections 4 and 5, EPA estimated that the cost to municipal and industrial 

dischargers to meet FDEP 2009 draft criteria are the same as the costs to municipal and industrial 

discharger to meet EPA’s nutrient criteria, even though the criteria themselves are different. Thus, the 

incremental cost of meeting EPA’s criteria would be zero compared to a baseline of the FDEP’s July 

2009 draft nutrient criteria. 

A.3 Urban Stormwater

Based on the data and methods described in Section 7, EPA estimated acres of urban land in the 

incrementally impaired watersheds for lakes and streams based on FDEP’s July 2009 draft nutrient 

criteria that could potentially need incremental controls. Exhibit A-3 summarizes this analysis.

Exhibit A-3: Urban Land in Incrementally Impaired Watersheds based on FDEP’s 2009 

Draft Nutrient Criteria Potentially Needing Controls

Land Type Estimated Acres in Incrementally 

Impaired Watersheds

Estimated Acres Potentially 

Needing Controls1 

MS4 Phase I Urban 44,300 0 - 34,500

MS4 Phase II Urban 72,700 22,200

Non-MS4 Urban 91,200 25,100

Total 208,200 47,300 - 81,900

Note: Detail may not add to total due to independent rounding

1. 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.

Using the median cost for stormwater controls from FDEP (2010b) of $6,800 per acre and O&M costs 

equal to 5% of capital costs [consistent with FDEP (2010b) assumption of O&M equal to 5% of capital 
November 2010 Appendix A. Incremental Costs of EPA’s Criteria Compared to FDEP’s 2009 Draft Criteria A-3

costs], EPA estimated the cost of controls for the acres potentially needing controls. These estimates are 

shown in Exhibit A-4. 

Exhibit A-4: Estimated Urban Stormwater Cost Scenarios Associated with FDEP’s July 

2009 Draft Nutrient Criteria (2010 dollars)

Land Type Acres Needing 

Controls1 

Capital Cost

(millions $)2 

O&M Cost

(millions $)3 

Annual Cost

(millions $)4

MS4 Phase I Urban 0 - 34,500 $0 - $236.0 $0 - $11.8 $0 - $34.1

MS4 Phase II Urban 22,200 $151.8 $7.6 $21.9

Non-MS4 Urban 25,100 $171.8 $8.6 $24.8

Total 47,300 - 81,900 $323.6 - $559.7 $16.2 - $28.0 $46.7 - $80.8

1. See Exhibit 7-2. 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.

2. Represents acres needing controls multiplied by median unit costs of stormwater retrofit costs from 

FDEP (2010b).

3. Represents 5% of capital costs.

4. Capital costs annualized at 7% over 20 years plus annual O&M costs.

Exhibit A-5 shows the calculation of incremental costs of EPA’s rule compared to these baseline costs. 

Exhibit A-5: Potential Incremental Urban Stormwater Costs: FDEP July 2009 Draft 

Criteria Baseline

Scenario Total Annual Costs ($/yr)

Cost to Attain EPA’s Rule1 $60.5 - $108.0

Costs to Attain FDEP 2009 Draft Criteria1 $46.7 - $80.8

Difference2 $13.7 - $27.2

1. Compared to baseline reflecting current impairments. 

2. Represents difference between incremental costs needed for compliance with EPA’s rule compared to the 

baseline reflective of current impairments and costs needed for compliance with FDEP’s 2009 draft nutrient 

criteria compared to the baseline reflective of current impairments. 

A.4 Agriculture

EPA used the data and methods described in Section 8 to estimate potential costs to agricultural 

operations associated with meeting FDEP’s July 2009 draft nutrient criteria. Exhibit A-6 shows estimates 

of the potential incremental costs to agriculture that may be needed to reduce nutrients to levels that attain 

FDEP’s criteria for lakes and streams. EPA derived these estimates by multiplying the number of 

potentially affected acres in each category of agricultural operation with the unit costs of the Owner plus 

Typical programs from SWET (2008a). 
November 2010 Appendix A. Incremental Costs of EPA’s Criteria Compared to FDEP’s 2009 Draft Criteria A-4

Exhibit A-6: Potential Agricultural Control Costs Associated with Incrementally Impaired 

Lakes and Streams based on FDEP’s 2009 Draft Nutrient Criteria

Agricultural BMP Category Area (acres)1 

Owner plus

Typical 

Program Unit 

Cost ($/ac/yr)2

Total Owner 

plusTypical Program 

Costs ($/yr) 

Animal Feeding 1,300 - 1,312 $18.56 $24,131 - $24,348

Citrus 17,637 - 53,962 $156.80 $2,765,475 - $8,461,215

Cow Calf Production, Improved 

Pastures 163,128 - 212,480 $15.84 $2,583,953 - $3,365,685

Cow Calf Production, Unimproved 

Pastures 44,484 - 51,883 $4.22 $187,902 - $219,154

Cow Calf Production, Rangeland 

and Wooded 67,796 - 79,109 $4.22 $286,369 - $334,155

Row Crop 14,637 - 18,859 $70.40 $1,030,446 - $1,327,700

Cropland and Pastureland (general)3 58,756 - 64,860 $27.26 $1,601,448 - $1,767,826

Sod/Turf Grass 2,063 $35.20 $72,624

Ornamental Nursery 849 - 993 $70.00 $59,413 - $69,483

Dairies 588 - 627 $334.40 $196,576 - $209,550

Horse Farms 1,190 - 1,191 $15.84 $18,854 - $18,860

Field Crop (Hayland) Production 168,271 - 195,878 $18.56 $3,123,114 - $3,635,491

Other Areas4 30,430 - 37,251 $18.56 $564,784 - $691,386

Total5 571,130 - 720,467 -- $12,515,087 - $20,197,475

Note: Detail may not add to total due to independent rounding.

1. Based on GIS analysis of land use data from five water management districts (for entire state) and FDACS 

BMP program NOI GIS data layer. Low end reflects acres in incrementally impaired HUCs (that are not 

included in HUCs for baseline impairment) that are not enrolled in BMPs under FDACS; high end reflects all 

acres in incrementally impaired HUCs, regardless of FDACS BMP enrollment.

2. Cost estimates from SWET (2008a); representative of 2010 prices (personal communication with D. 

Bottcher, 2010).

3. Owner/typical BMP unit costs based on average costs for improved pastures, unimproved/wooded 

pasture, row crops, and field crops.

4. Includes FLUCCS Level 3 codes 2160, 2200, 2230, 2400, 2410, 2500, 2540, and 2550.

5. Excludes land not in production.

 

In addition to agricultural controls to control lakes and streams, controls may also be needed on other 

agricultural land to meet FDEP’s draft nitrate-nitrite criterion for clear streams and springs. Thus, based 

on the method described in Section 8.3.2, EPA assumed that nutrient management would be appropriate 

on all land categorized as general agriculture and specialty crop that is not impaired under the narrative 

criterion or would need controls to meet the draft lakes and streams criteria (1.2 million acres). Exhibit 

A-7 shows the estimate of the potential cost of additional nutrient management to protect Florida springs. 
November 2010 Appendix A. Incremental Costs of EPA’s Criteria Compared to FDEP’s 2009 Draft Criteria A-5

Exhibit A-7: Potential Agricultural Control Costs Associated with Impaired Springs

based on FDEP’s 2009 Draft Nitrate-Nitrite Criterion

Nutrient Management 

Program Type

Total Acres 

in Florida1 

Acres Needing 

Nutrient 

Management2 

Unit Cost 

($/acre)3 Total Cost Annual Cost ($/year)4 

General Agriculture 4,885,643 1,137,931 $10 $11,379,311 $4,336,105

Specialty Crop5 1,057,107 113,366 $20 $2,267,323 $863,967

Total 5,942,750 1,251,297 -- $13,646,634 $5,200,073

1. Excludes unimproved and woodland pastures, abandoned groves, aquaculture, tropical fish farms, open 

rural lands, and fallow cropland.

2. Calculated by subtracting agricultural land in incrementally impaired watersheds needing controls and 

agricultural land types participating in FDACS BMP program (assuming all Tri-county agricultural area land 

is regular nutrient management land) from total land use area in Florida.

3. Source: FL EQIP (2009a). 

4. Costs annualized at 7% over 3 years.

5. Specialty crop land use types include row crops, citrus groves, fruit orchards, other groves, nurseries and 

vineyards, sod farms, and floriculture.

Exhibit A-8 summarizes the estimated costs to agricultural operations that could potentially be associated 

with FDEP’s 2009 draft nutrient criteria. 

Exhibit A-8: Potential Annual Control Costs for Agricultural Sources based on FDEP’s 

July 2009 Draft Nutrient Criteria

Waterbody Type Acres Needing BMPs Annual Costs1 

Lakes and Streams 571,130 - 720,467 $12.5 - $20.2

Springs 1,251,297 $5.2

Total 1,822,427 – 1,971,764 $17.7 - $25.4

1. For lakes and flowing waters, low cost reflects owner/typical BMP program estimated by SWET (2008a) 

for the Caloosahatchee River and St. Lucie River watersheds for all acres in incrementally impaired 

watersheds not enrolled in FDACS BMP program; high cost represents a more aggressive level of control 

on all agricultural acres in the incrementally impaired watersheds based on the alternative program from 

SWET (2008a). For springs, costs represent implementation of nutrient management on all farms in the 

state not located in a baseline or incrementally impaired watershed.

 

Exhibit A-9 shows the calculation of incremental costs of EPA’s rule compared to these baseline costs. 

Exhibit A-9: Potential Incremental Agriculture Costs: FDEP July 2009 Draft Criteria 

Baseline

Scenario Total Annual Costs ($/yr)

Cost to Attain EPA’s Rule1 $19.9 - $20.3

Costs to Attain FDEP 2009 Draft Criteria1 $17.7 - $25.4

Difference2 (-$2.4) - $2.1

1. Compared to narrative criterion baseline. 

2. Represents difference between incremental costs needed for compliance with EPA’s rule compared to the

narrative criterion baseline and costs needed for compliance with FDEP’s 2009 draft nutrient criteria 

compared to the narrative criterion.
November 2010 Appendix A. Incremental Costs of EPA’s Criteria Compared to FDEP’s 2009 Draft Criteria A-6

A.5 Septic Systems

Based on the method described in Section 9, EPA estimated that there are 6,541 active septic systems 

within 500 feet of water in 10-digit HUCs in watersheds that could be identified as impaired based on 

FDEP’s 2009 draft numeric nutrient criteria (that are not already on the 303(d) list for nutrients or under a 

TMDL). Thus, potential annual costs associated with FDEP’s July 2009 draft nutrient criteria may range 

from $5.3 million to $8.5 million. 

Exhibit A-10 shows the calculation of incremental costs of EPA’s rule compared to these baseline costs. 

Exhibit A-10: Potential Incremental Costs Associated with Upgrading Septic Systems: 

FDEP 2009 Draft Criteria Baseline

Scenario Total Annual Costs ($/yr)

Cost to Attain EPA’s Rule1 $6.6 - $10.7

Costs to Attain FDEP 2009 Draft Criteria1 $5.3 - $8.5

Difference2 $1.3 - $2.2

1. Compared to narrative criterion baseline. 

2. Represents difference between incremental costs needed for compliance with EPA’s rule compared to the 

narrative criterion baseline and costs needed for compliance with FDEP’s 2009 draft nutrient criteria 

compared to the narrative criterion.

A.6 Government Costs

FDEP may incur costs associated with development of additional TMDLs. Because existing TMDLs 

cover an average of two waterbodies each, FDEP may need to develop 113 new TMDLs (225 impaired

WBIDs ÷ 2 = 113 TMDLs). EPA (2001) indicates that TMDL development for two similar pollutants 

costs an average of approximately $47,000. Thus, total TMDL development cost associated with FDEP’s 

draft nutrient criteria could be $5.3 million, or $590,000 per year assuming FDEP adheres to its 9-year 

TMDL development cycle. The incremental costs of TMDL development under EPA’s rule compared to 

the FDEP draft numeric nutrient criteria baseline is approximately $0.3 million per year ($0.9 million - 

$0.6 million). 

A.7 Summary and Comparison

Exhibit A-11 summarizes the incremental costs of EPA’s rule based on the FDEP baseline, calculated as 

the difference between potential annual incremental costs of attaining EPA’s criteria based on the 

narrative criterion baseline and the estimated incremental costs based on attaining FDEP’s 2009 draft 

nutrient criteria compared to the narrative criterion baseline. 
November 2010 Appendix A. Incremental Costs of EPA’s Criteria Compared to FDEP’s 2009 Draft Criteria A-7

Exhibit A-11: Potential Incremental Costs Associated with EPA’s Numeric Nutrient 

Criteria: FDEP 2009 Draft Criteria Baseline (2010 dollars)

Source Sector

Annual Cost (millions)

Cost to Attain 

EPA’s Rule

Costs to Attain FDEP 

2009 Draft Criteria Difference

Municipal Wastewater1 $22.3 - $38.1 $22.3 - $38.1 $0.0

Industrial Dischargers2 $25.4 $25.4 $0.0

Urban Stormwater4 $60.5 - $108.0 $46.7 - $80.8 $13.7 - $27.2 

Agriculture5 $19.9 - $23.0 $17.7 - $25.4 $2.1 - (-$2.4)

Septic Systems6 $6.6 - $10.7 $5.3 - $8.5 $1.3 - $2.2

Government/Program Implementation $0.9 $0.6 $0.3

Total $135.5 - $206.1 $118.0 - $178.9 $17.5 - $27.2

Note: Detail may not add to total due to independent rounding.

BNR = biological nutrient removal; FDEP = Florida Department of Environmental Protection; TMDL = 

total maximum daily load; TN = total nitrogen; TP = total phosphorus

1. Based on upgrading existing treatment processes to advanced BNR.

2. Based on extrapolation of average annual costs per flow for random sample of dischargers stratified by 

industrial category.

4. Based on median stormwater control costs from FDEP (2010a), and scenario of need for structural 

controls on land developed before 1982.

5. Based on implementing nutrient management on all crop land outside of incrementally and baseline 

impaired watersheds and scenarios in which all agricultural land not enrolled in the FDACS BMP program in 

incrementally impaired watersheds incurs owner/typical program costs from SWET (2008a) or all 

agricultural land in incrementally impaired watersheds incurs owner/typical costs based on SWET (2008a).

6. Based on upgrading to advanced nutrient removal active septic systems within 500 feet of water (based on 

GIS land use data) in incrementally impaired watersheds.

7. Based on average costs to complete TMDLs for incrementally impaired waters under a 9-year schedule.
November 2010 Appendix B. Sensitivity Analysis: Potential Impacts without No DPVs for Streams Criteria B-1

Appendix B . S ens itivity Analys is : P otential Impac ts without DP V s for 

S tream C riteria

This Appendix provides analysis of the sensitivity of incremental impairments and costs to the 

assumption that downstream protection value (DPV) criteria are applicable to all WBIDs intersecting 

lakes. 

B.1 Incrementally Impaired Streams

EPA’s estimates of incremental impairments and potential costs reflect the assumption that DPVs for 

lakes would apply in all streams intersecting lake WBIDs. However, the WBID data does not include 

information on direction of flow, and some stream segments may be downstream rather than upstream of 

lakes. Thus, the assumption that the DPV would apply to downstream WBIDs will overstate potential 

incremental impairments and costs. Also, even for upstream WBIDs, there may be instances in which the 

DPVs would not be relevant to the entire stream (some WBIDs are much larger than others). 

To estimate the change in incremental impairments associated with exceedances of stream criteria without 

consideration of DPVs, EPA used the same data and method described in Section 6.1 and 6.2. Exhibit B1 summarizes the potential incremental impairments with and without considering DPVs. 

Exhibit B-1: Potential Incrementally Impaired Streams with and without Consideration of

DPVs

Category

Number of Stream WBIDs

DPVs Apply to Streams 

Intersecting Lakes1 

DPVs Do Not Apply 

to Streams Difference

Total in State 3,901 3,901 0

Not Listed/Covered by TMDL2 3,608 3,608 0

Nutrient Data in IWR Run 403 1,273 1,273 0

Sufficient Data Available4 930 930 0

Potentially Exceeding Criteria5 153 121 32

IWR = Impaired Waters Rule

TMDL = total maximum daily load

WBID = waterbody identification

1. Based on meeting applicable DPV in all WBIDs intersecting lakes, without consideration of direction of 

flow or site specific modeling, which may overstate incremental impairments under the rule.

2. As reported in TMDL documents and FDEP (2009c).

3. Data within last 5 years meeting data quality requirements.

4. Annual geometric means based on at least 4 samples with one sample from May to September and one 

sample from October to April in a given year.

5. Based on annual geometric mean exceeding the applicable TN or TP criterion more than once in a three 

year period.

B.2 Municipal and Industrial Point Source Dischargers

The estimated costs to municipal WWTP and industrial dischargers remain the same with the exclusion of 

DPVs from the analysis. 
November 2010 Appendix B. Sensitivity Analysis: Potential Impacts without No DPVs for Streams Criteria B-2

B.3 Urban Stormwater

To estimate costs to urban stormwater sources, EPA used the methods described in Section 7 based on 

GIS analysis of urban land use surrounding waters impaired based on EPA’s numeric nutrient criteria not 

accounting for DPVs for streams. Exhibit B-2 shows the estimated number of acres, the acres potentially 

needing stormwater controls, and the annual costs of those controls. 

Exhibit B-2: Estimated Incremental Urban Stormwater Costs: No DPVs

Land Type Urban Acres Acres Needing 

Controls1 

Capital Cost

(millions $)2 

O&M Cost

(millions $)3 

Annual Cost

(millions $)4

MS4 Phase I Urban 60,600 0 – 47,200 $0 - $322.5 $0 - $16.1 $0 - $46.6

MS4 Phase II Urban 86,700 29,600 $202.2 $10.1 $29.2

Non-MS4 Urban 95,700 26,500 $178.4 $8.9 $25.8

Total 243,000 55,700 – 103,200 $380.6 - $703.1 $19.0 - $35.2 $55.0 - $101.5

1. 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.

2. Represents acres needing controls multiplied by median unit costs of stormwater retrofit costs from 

FDEP (2010b).

3. Represents 5% of capital costs.

4. Capital costs annualized at 7% over 20 years plus annual O&M costs.

Compared to the results obtained considering potential applicability of DPVs, costs for control of urban 

sources may be on the order of $5.5 million to $6.5 million less if DPVs do not apply ($60.5 million - $55 

million = $5.5 million; $108 million - $101.5 million = $6.5 million).

B.4 Agriculture

To estimate the costs to agriculture associated with EPA’s numeric nutrient criteria not accounting for 

DPVs for streams, EPA used the methods described in Section 8. Exhibit B-3 shows estimates of the 

potential costs to agriculture of implementing owner plus typical BMP programs from SWET (2008a) for 

the St. Lucie and Caloosahatchee TMDLs. The range of potentially affected acres represent 1) agricultural 

acres near incrementally impaired waters that are not currently enrolled in the FDACS BMP program and 

2) all agricultural acres near incrementally impaired waters whether or not they are currently enrolled in 

the FDACS BMP program.
November 2010 Appendix B. Sensitivity Analysis: Potential Impacts without No DPVs for Streams Criteria B-3

Exhibit B-3: Potential Incremental Agricultural Control Costs for Lakes and Streams: No 

DPVs

Agricultural BMP Category Area (acres)1 

Owner plus

Typical 

Program Unit 

Cost ($/ac/yr)2

Total Owner

plusTypical Program 

Costs ($/yr) 

Animal Feeding 1,575 - 1,607 $18.56 $29,228 - $29,817

Citrus 15,429 - 27,290 $156.80 $2,419,333 - $4,279,024

Cow Calf Production, Improved 

Pastures 135,594 - 150,185 $15.84 $2,147,805 - $2,378,928

Cow Calf Production, Unimproved 

Pastures 43,481 - 45,483 $4.22 $183,664 - $192,121

Cow Calf Production, Rangeland 

and Wooded 66,310 - 67,572 $4.22 $280,093 - $285,425

Row Crop 7,488 - 9,449 $70.40 $527,139 - $665,240

Cropland and Pastureland (general)3 152,976 - 160,814 $27.26 $4,169,512 - $4,383,135

Sod/Turf Grass 1,977 $35.20 $69,587

Ornamental Nursery 840 $70.00 $58,783

Dairies 583 - 621 $334.40 $194,803 - $207,777

Horse Farms 1,285 $15.84 $20,359

Field Crop (Hayland) Production 173,070 - 193,357 $18.56 $3,212,186 - $3,588,706

Other Areas4 53,275 - 66,140 $18.56 $988,775 - $1,227,556

Total5 653,881 - 726,620 -- $14,301,260 - $17,386,457

Note: Detail may not add to total due to independent rounding.

1. Based on GIS analysis of land use data from five water management districts (for entire state) and FDACS 

BMP program NOI GIS data layer. Low end reflects acres in incrementally impaired HUCs (that are not 

included in HUCs for baseline impairment) that are not enrolled in BMPs under FDACS; high end reflects all 

acres in incrementally impaired HUCs, regardless of FDACS BMP enrollment.

2. Cost estimates from SWET (2008a); representative of 2010 prices (personal communication with D. 

Bottcher, 2010).

3. Owner/Typical BMP unit costs based on average costs for improved pastures, unimproved/wooded 

pasture, row crops, and field crops.

4. Includes FLUCCS Level 3 codes 2160, 2200, 2230, 2400, 2410, 2500, 2540, and 2550.

5. Excludes land not in production.

EPA estimated the costs of nutrient management to reduce nitrate-nitrite in springs as described in 

Section 8.3.2. As shown in Exhibit B-4, the nutrient management costs increase slightly when excluding 

DPVs from the analysis because fewer acres would need BMPs for lake and stream impairments.
November 2010 Appendix B. Sensitivity Analysis: Potential Impacts without No DPVs for Streams Criteria B-4

Exhibit B-4: Potential Agricultural Control Costs Associated with Incrementally 

Impaired Springs: No DPVs

Nutrient Management 

Program Type

Total Acres 

in Florida1 

Acres Needing 

Nutrient 

Management2 

Unit Cost 

($/acre)3 Total Cost Annual Cost ($/year)4 

General Agriculture 4,885,643 1,044,085 $10 $10,440,846 $3,978,502

Specialty Crop5 1,057,107 122,070 $20 $2,441,409 $930,303

Total 5,942,750 1,166,155 -- $12,882,255 $4,908,805

1. Excludes unimproved and woodland pastures, abandoned groves, aquaculture, tropical fish farms, open 

rural lands, and fallow cropland.

2. Calculated by subtracting agricultural land in incrementally impaired watersheds needing controls and 

agricultural land types participating in FDACS BMP program (assuming all Tri-county agricultural area land 

is regular nutrient management land) from total land use area in Florida.

3. Source: FL EQIP (2009a). 

4. Costs annualized at 7% over 3 years.

5. Specialty crop land use types include row crops, citrus groves, fruit orchards, other groves, nurseries and 

vineyards, sod farms, and floriculture.

Exhibit B-5 summarizes the estimated costs to agricultural operations that could potentially be indirectly 

associated with EPA’s numeric nutrient criteria not accounting for DPVs for streams.

Exhibit B-5: Potential Annual Incremental Control Costs for Agricultural Sources: No 

DPVs

Waterbody Type Acres Needing BMPs Annual Costs1 

Lakes and Flowing waters 653,881 - 726,620 $14,301,260 - $17,386,457

Springs 1,166,155 $4,908,805

Total 1,820,036 – 1,892,775 $19,210,065 - $22,295,261

1. For lakes and flowing waters, low cost reflects owner/typical BMP program estimated by SWET (2008a) 

for the Caloosahatchee River and St. Lucie River watersheds for all acres in incrementally impaired 

watersheds not enrolled in FDACS BMP program; high cost represents a more aggressive level of control 

on all agricultural acres in the incrementally impaired watersheds based on the alternative program from 

SWET (2008a). For springs, costs represent implementation of nutrient management on all farms in the 

state not located in a baseline or incrementally impaired watershed.

Compared to the results obtained considering potential applicability of DPVs, agricultural control costs 

associated with attaining the criteria may be $0.6 million to $0.7 million less if DPVs are not applicable 

to streams intersecting lakes ($19.9 million - $19.2 million = $0.6 million; $23.0 million - $22.3 million = 

$0.7 million). 

B.5 Septic Systems

EPA estimated that there are 8,043 active septic systems within 500 feet of water in 10-digit HUCs in 

watersheds that could be identified as impaired based on EPA’s numeric nutrient criteria, not considering 

DPVs for streams intersecting lakes based on the method described in Section 9. Total potential annual 

costs could range from $6.4 million to $10.5 million. 

Compared to the results obtained considering potential applicability of DPVs, septic system control costs 

associated with attaining the criteria if DPVs are not applicable to streams intersecting lakes are
November 2010 Appendix B. Sensitivity Analysis: Potential Impacts without No DPVs for Streams Criteria B-5

approximately $0.1 million to $0.2 million less per year ($6.6 million - $6.4 million = $0.1 million; $10.7 

million - $10.5 million = -$0.2 million). 

B.6 Government Costs

EPA determined that existing nutrient-related TMDLs in Florida address an average of two WBIDs each. 

Using the average number of WBIDs per TMDL, EPA estimated that 155 additional nutrient TMDLs

may be required under the scenario in which DPVs for streams are excluded from the analysis (e.g., 309 

incrementally impaired WBIDs ÷ 2 WBIDs per TMDL). Multiplying the average per TMDL cost of 

$47,000 by EPA’s estimate of 155 additional TMDLs results in an estimated total cost of approximately 

$7.3 million, or approximately $809,000 per year based on a 9-year TMDL development schedule. 

Compared to the results obtained considering potential applicability of DPVs, annual government costs

for TMDL development may be $0.1 million less if DPVs are not applicable to streams intersecting lakes 

($0.9 million - $0.8 million = $0.1 million).

B.7 Summary and Comparison

Exhibit B-6 summarizes EPA’s estimates of potential annual incremental costs associated with excluding 

DPVs for streams from the analysis compared to the estimated incremental costs based on application of 

DPVs to any stream intersecting a lake. 

Exhibit B-6: Comparison of Potential Annual Costs Associated with Numeric Nutrient 

Criteria (2010 dollars)

Source Sector Annual Cost (millions)

No DPV Scenario DPV Scenario

Municipal Wastewater1 $22.3 - $38.1 $22.3 - $38.1

Industrial Dischargers2 $25.4 $25.4

Urban Stormwater4 $55.0 - $101.5 $60.5 - $108.0

Agriculture5 $19.2 - $22.3 $19.9 - $23.0

Septic Systems6 $6.4 - $10.5 $6.6 - $10.7

Government/Program Implementation $0.8 $0.9

Total $129.1 - $198.6 $135.5 - $206.1

Note: Detail may not add to total due to independent rounding.

BNR = biological nutrient removal; DPV = downstream protection value; TMDL = total maximum daily 

load; TN = total nitrogen; TP = total phosphorus

1. Based on upgrading existing treatment processes to advanced BNR.

2. Based on extrapolation of average annual costs per flow for random sample of dischargers stratified by 

industrial category.

4. Based on median stormwater control costs from FDEP (2010a), and scenario of need for structural 

controls on land developed before 1982.

5. Based on implementing nutrient management on all crop land outside of incrementally and baseline 

impaired watersheds and scenarios in which all agricultural land not enrolled in the FDACS BMP program in 

incrementally impaired watersheds incurs owner/typical program costs from SWET (2008a) or all 

agricultural land in incrementally impaired watersheds incurs owner/typical costs based on SWET (2008a).

6. Based on upgrading to advanced nutrient removal active septic systems within 500 feet of water (based on 

GIS land use data) in incrementally impaired watersheds.

7. Based on average costs to complete TMDLs for incrementally impaired waters under a 9-year schedule.
November 2010 Appendix B. Sensitivity Analysis: Potential Impacts without No DPVs for Streams Criteria B-6

As shown in the exhibit, excluding DPVs for streams from the analysis results in total annual costs 

approximately $6.4 million to $7.4 million less than the incremental costs EPA estimated taking DPVs for 

streams intersecting lakes into account. 
November 2010 Appendix C. Municipal WWTP Cost Estimates C-1

Appendix C. Munic ipal WWT P C os t E s timates

Exhibit C-1 shows the cost estimates for municipal WWTP discharging to lakes or flowing waters in 

Florida. 

Exhibit C-1: Potential Costs to Municipal WWTPs for Compliance with Numeric Nutrient 

Criteria

NPDES

No. Discharger Name Flow (mgd)

Nutrient

Region/ 

Lake Type

Reductions 

Needed Total Capital 

Costs

Annual 

O&M 

TN TP Costs

Majors

FL0037966 Orlando-Iron Bridge 40 Peninsula No No $0 $0

FL0040436 Pinellas Co - S. Cross 

Bayou 33 West Central No No $0 $0 

FL0039772 W. Carl Dicks WWTP 13.7 Peninsula No No $0 $0

FL0128937 Clearwater City of 

Northeast 13.5 West Central No No $0 $0 

FL0033251 Altamonte 

Springs/Swofford 12.5 Peninsula No No $0 $0

FL0038849 Orange Cty-East Svc Area 

WWTP 11.2 Peninsula No No $0 $0

FL0027821 River Oaks AWWTP 10 West Central Yes Yes $13.0 – 24.8 $1.4 – 1.7

FL0026557 Plant City STP 8 West Central Yes No $5.6 – 6.3 $0.3 – 0.5

FL0023493 JEA - Mandarin WWTF 7.5 Peninsula No Yes $5.4 – 12.9 $0.7 – 1.2

FL0027251 Gainesville-Main St WTP

1 and 2 7.5 Peninsula No Yes $5.4 – 12.9 $0.7 – 1.23

FL0020303 Deland/Wiley M. Nash 

Water 7.37 Peninsula No Yes $5.3 – 12.7 $0.7 – 1.2

FL0020141 Sanford-Municipal WTP 7.3 Colored No No $0 $0

FL0021369 Bradenton WTP 6 West Central Yes Yes $7.8 – 14.9 $0.8 – 1.0

FL0040983 Hillsborough Cty Valrico 

WWTP 6 West Central Yes Yes $7.8 – 14.9 $0.8 – 1.0 

FL0036820 Hillsborough Cty - Dale 

Mabry 6 West Central No Yes $4.3 – 10.3 $0.6 – 1.0

FL0025151 Clay Cty Miller St WWTP 5 Peninsula No Yes $3.6 – 8.6 $0.5 – 0.8

FL0036048 Winter Haven #3 

Wahneta 5 Peninsula No No $0 $0 

FL0043834 Fleming Island Reg.

WWTF 4 Peninsula No Yes $2.9 – 6.9 $0.4 – 0.6

FL0028061 Hillsborough CoSouthwest WTP 3.95 West Central Yes Yes $5.1 – 9.8 $0.6 – 0.7

FL0041441 Venice - Eastside WWTP 3 West Central Yes Yes $3.9 – 7.4 $0.4 – 0.5

FL0040061 Palatka WWTF 3 Peninsula No No $0 $0

FL0036251 Wekiva Hunt Club STP 2.9 Peninsula No No $0 $0

FL0023922 Orange Park-Ash St STP 2.5 Peninsula No Yes $1.8 – 4.3 $0.2 – 0.4

FL0021903 Milton City of (STP) 2.5 Panhandle

West No Yes $1.9 – 4.3 $0.2 – 0.4

FL0042625 Seminole Cty Dept of 2.5 Peninsula No No $0 $0
November 2010 Appendix C. Municipal WWTP Cost Estimates C-2

Exhibit C-1: Potential Costs to Municipal WWTPs for Compliance with Numeric Nutrient 

Criteria

NPDES

No. Discharger Name Flow (mgd)

Nutrient

Region/ 

Lake Type

Reductions 

Needed Total Capital 

Costs

Annual 

O&M 

TN TP Costs

Evio Srv

FL0027511 William Tyson WWTP 2 Peninsula No No $0 $0

FL0020109 Winter Garden STP 2 Clear No No $0 $0

FL0039721 Clay Cty Ridaught 

Landing WWTP 1.875 Peninsula No No $0 $0 

FL0028126 Starke-Municipal STP 1.65 Peninsula Yes Yes $2.1 – 4.1 $0.2 – 0.3

FL0026867 Blountstown-STP 1.5 Panhandle

West Yes No $1.1 – 1.2 $0.06 – 0.1

FL0029033 City of Quincy WWTP 1.5 Panhandle

East No Yes $1.1 – 2.6 $0.1 – 0.2

FL0027731 Bonifay STP 1.4 Panhandle

West Yes Yes $1.8 – 3.5 $0.2

FL0040495 MacClenny WTP 1.3 North 

Central Yes Yes $1.7 – 3.2 $0.2

FL0031402 FL State Hospital 1.3 Panhandle

East Yes Yes $1.7 – 3.2 $0.2

FL0026387 Perry STP 1.25 Panhandle 

East No No $0 $0 

FL0027880 Jasper-WWTP 1.2 North 

Central No No $0 $0

FL0038555 Fac1 of Graceville WWTP 1.1 Panhandle

West Yes Yes $1.4 – 2.7 $0.2

FL0103349 Titusville South – Blue 

Heron 4 Peninsula No No $0 $0

FL0428523 North Bay WWTP 1.5 Panhandle 

West No No $0 $0

FL0043214 Martin County 

Consolidated 1.97 Peninsula No No $0 $0

FL0102679 BCUD/South Central 5.5 Peninsula No No $0 $0

FL0038857 Apalachicola City 1 Panhandle 

West No No $0 $0

FL0027839 Monticello-STP 1 Panhandle

East Yes Yes $1.3 – 2.5 $0.1 – 0.2

Majors Total $85.9 – 173.9 $9.6 – 13.9

Minors

FL0186261 City of Clearwater -

Master Reuse System 40 West Central No No $0 $0

FL0127272 Pasco County Master 

Reuse System

26.75 West Central No No $0 $0

FL0112895 G.R.U. STP #5-Kanapaha 10 Colored No Yes $7.2 – 17.2 $0.9 – 1.6

FL0134589 Dolomite Utilities 

Fruitville 1.5 West Central Yes Yes $1.9 – 3.7 $0.2 – 0.3

FL0043591 JEA - Julington Creek 

WWTF 1 Peninsula No Yes $0.7 – 1.7 $0.1 – 0.2

FL0022853 USA Nat Guard Camp 0.9 Peninsula Yes Yes $1.2 – 2.2 $0.1 – 0.2
November 2010 Appendix C. Municipal WWTP Cost Estimates C-3

Exhibit C-1: Potential Costs to Municipal WWTPs for Compliance with Numeric Nutrient 

Criteria

NPDES

No. Discharger Name Flow (mgd)

Nutrient

Region/ 

Lake Type

Reductions 

Needed Total Capital 

Costs

Annual 

O&M 

TN TP Costs

Blanding

FL0020338 Mulberry STP 0.75 West Central Yes No $0.5 – 0.6 $0

FL0020915 Green Cove Springs WTP 0.75 Peninsula No No $0 $0

FL0021466 Auburndale Allred 

WWTP 0.65 Peninsula No No $0 $0

FL0030210 Green Cove SpgsReynolds 0.5 Peninsula No No $0 $0

FL0027669 Chattahoochee City of

(STP) 0.5 PanhandleEast No No $0 $0

FL0040029 Avon Park Correctional 

Inst 0.5 Peninsula Yes Yes $0.6 – 1.2 $0.07 – 0.09

FL0102202 Pace Water System Inc. 

WWTP #1 0.45 PanhandleWest No No $0 $0

FL0027812 Baldwin WWTF 0.4 Peninsula Yes Yes $0.5 – 1.0 $0.06 – 0.07

FL0027791 Cross City-STP #1 0.4 North 

Central Yes Yes $0.5 – 1.0 $0.06 – 0.07

FL0039896 Pebble Creek Village 

WWTF 0.4 West Central No No $0 $0

FL0040291 Charlotte Co Util - East 

Port 0.385 Peninsula No No $0 $0

FL0021610 Crescent City STP 0.35 Colored No No $0 $0

FL0043079 Hilliard 0.32 Peninsula Yes Yes $0.4 – 0.8 $0.04 – 0.06

FL0038407 Callahan Town of 0.3 Peninsula Yes Yes $0.4 – 0.7 $0.04 – 0.05

FL0020907 Bunnell WTP 0.3 Peninsula No No $0 $0

FL0117471 SJCUD - State Road 207 

WWTF 0.25 Peninsula Yes Yes $0.3 – 0.6 $0.04

FL0122076 Rice Creek Utility 

Company 0.225 West Central No No $0.0 $0

FL0020125 Wewahitchka City of

(STP) 0.2 PanhandleWest Yes Yes $0.3 – 0.5 $0.03

FL0042315 Hastings STP 0.12 Peninsula No Yes $0.09 – 0.2 $0.01 – 0.02

FL0119644 Lake Suzy Utility WWTP 0.087 West Central Yes Yes $0.1 – 0.2 $0.01 – 0.02

FL0040215 Brittany Estates MHP

WWTP 0.06 Peninsula No No $0 $0

FL0043389 Hiawatha Condominiums 0.036 Peninsula No No $0 $0

FL0040207 Noma STP 0.025 Panhandle

West Yes Yes $0.03 – 0.06 $0.003 –0.004

FL0043419 Study Estates 0.017 Peninsula No No $0 $0

FL0043150 Napoli's Trailer Park 0.015 Peninsula Yes Yes $0.02 – 0.04 $0.002 –

0.003

FL0042617 Point Buena Vista MHP 0.015 Peninsula Yes Yes $0.02 – 0.04 $0.002 –

0.003

FL0023426 Ideal Mobile Home Park 

WWTF 0.011 Peninsula No No $0 $0
November 2010 Appendix C. Municipal WWTP Cost Estimates C-4

Exhibit C-1: Potential Costs to Municipal WWTPs for Compliance with Numeric Nutrient 

Criteria

NPDES

No. Discharger Name Flow (mgd)

Nutrient

Region/ 

Lake Type

Reductions 

Needed Total Capital 

Costs

Annual 

O&M 

TN TP Costs

FL0113743 Middleburg Bluffs 0.009 Peninsula No No $0 $0

FL0043842 Cypress Landing WWTP 0.007 Peninsula No No $0 $0

FL0032662 Goodbread MHP 0.005 Peninsula Yes Yes $0.006 – 0.01 $0.0001

FL0043176 Paradise Point STP 0.005 Peninsula Yes Yes $0.006 – 0.01 $0.0001

FL0117951 JEA – Ponte Vedra 0.5 Peninsula Yes Yes $0.6 – 1.2 $0.07 – 0.09

FL0105066 Leesburg STP 3.5 Peninsula Yes Yes $4.5 – 8.7 $0.5 – 0.6

FL0034789 Mid-County Services 0.9 West Central No No $0 $0

FL0043109 State Road 16 WWTP 1.32 Peninsula Yes Yes $1.7 – 3.3 $0.2

FL0115231 Bailey's MHP 0.003 Peninsula Yes Yes $0.003 – 0.007 $0.0001

Minors Total $21.8 – 45.1 $2.5 – 3.6

BNR = biological nutrient removal

mgd = million gallons per day

MHP = mobile home park

NPDES = National Pollutant Discharge Elimination System

O&M = operation and maintenance

STP = sewage treatment plant

TMDL = total maximum daily load

TN = total nitrogen

TP = total phosphorus

WWTF = wastewater treatment facility

WWTP = wastewater treatment plant
November 2010 Appendix D: Industrial Sample Discharger Analyses D-1

Appendix D. Indus trial S ample Dis c harger Analys es

F lorida R oc k Indus tries- Gulf Hammock Quarry

NPDES permit number: FL0044300 

Major/minor: Minor

SIC code: 1422 (Crushed and Broken Limestone) 

Industrial Category: Mining

Design Flow: Not reported 

Average Flow: 1.8 mgd (October 2004 through September 2005) 

Receiving Water: Wekiva River

Description

The facility processes excavated limestone by crushing, screening, and washing. Process wastewater 

generated from the washing of limestone and on-site stormwater are discharged to settling ponds. The 

settling ponds provide for evaporation, percolation, and recycling of the wastewater for processing 

limestone. Discharge of wastewater from the settling ponds through Outfall D-001 to an unnamed 

tributary of the Class III freshwaters of the Wekiva River is intermittent and rainfall dependent.. 

Summary of Effluent Data and Limits

There are no nitrogen or phosphorus effluent data in EPA’s PCS database for the facility. However, a 

2005 bioassay report indicates that TN and TP concentrations were <0.42 mg/L and 0.013 mg/L, 

respectively.

Incremental Controls 

The discharger is located in the Peninsula region, with TN and TP criteria of 1.54 mg/L and 0.12 mg/L, 

respectively. Based on effluent data from the 2005 bioassay report, the facility is likely discharging below 

these levels. Thus, incremental costs are zero for this discharger.
November 2010 Appendix D: Industrial Sample Discharger Analyses D-2

Mos aic F ertilizer - Hopewell

NPDES permit number: FL0032590 

Major/minor: Major

SIC code: 1475 (Phosphate rock)

Industrial Category: Mining

Design Flow: 1.3 mgd 

Average Flow: 5.24 mgd (average of monthly flows; no discharge since Sept. 2008) 

Receiving Water: Medard Reservoir

Description

Operations include phosphate mining and beneficiation facilities, phosphatic clay settling areas, sand 

tailings disposal areas, and a mine water recirculation system. Wastewater treatment consists of gravity 

settling sands, clays, and other suspended solids within earthen-diked settling areas. Clarified water is 

decanted to the mine water recirculation system for reuse. The recirculation system discharges when the 

storage capacity is exceeded due to excess rainfall contributions to the system and inflow of groundwater 

into mining cuts. 

Summary of Effluent Data and Limits

Exhibit D-1 summarizes average monthly effluent data for TN and TP from 2005 to 2010. 

Exhibit D-1. Effluent Data Summary, Mosaic Fertilizer - Hopewell

Pollutant Number of Observations Average Effluent 

(mg/L)1

Permit Limit 

(mg/L) Total Nondetect 2

Total nitrogen 25 0 0.66 3

Total phosphorus 26 0 0.77 5

Source: EPA (2010a)

1. TN and TP effluent data from 2005 to 2010. TN data represent average of maximum monthly values; TP 

data represent average of average monthly values.

2. TN and TP (mg/L) permit limit based on monthly maximum; average monthly TP limit is 3 mg/L. 

Incremental Controls 

There are no color data available in FDEP’s IWR database for Medard Reservoir. Information from the 

Southwest Florida Water Management District report on the Alafia Basin (1996) indicates that the 

Medard Reservoir is a colored lake. Thus, EPA’s criterion for TN is 1.0 mg/L and for TP is 0.05 mg/L. 

However, there are not sufficient data for TN and TP in FDEP’s IWR database (only one data point for 

each pollutant) from which to determine impairment under the rule. Thus, under the scenario of no 

dilution (e.g., receiving water is incrementally impaired or discharge flow is too large to allow a mixing 

zone), the discharger would likely receive effluent limits based on criteria end-of-pipe. Effluent data 

indicate that the discharger is likely discharging TN at concentrations below the applicable criterion; for 

TP, the discharger is likely discharging above applicable criteria and may need to implement some 

incremental level of control for compliance with potential effluent limits under the rule.

EPA (2008a) provides evidence of WWTPs meeting TP concentrations at or below 0.05 mg/L using a 

combination of chemical precipitation and filtration (see Section 4.2.3). Assuming similar treatment 

controls could allow the discharger to meet effluent limits based on meeting the TP criterion of 0.05 
November 2010 Appendix D: Industrial Sample Discharger Analyses D-3

mg/L, EPA estimated the cost of chemical precipitation and filtration. Flow data from EPA’s PCS 

database indicate that discharge flows vary greatly among discharge periods/events. Thus, control costs 

are based on the average discharge flow over the last 5 years (not accounting for months in which there 

was no discharge); this likely overestimates system size requirements, although costs for equalization 

basins or additional storage are not included. Based on average treatment costs for chemical precipitation 

and filtration expansion systems capable of achieving the necessary levels from EPA (2008a) for 

wastewater treatment plants, capital costs to treat approximately 5 mgd could be approximately $5.1 

million and annual O&M costs could be approximately $0.61 million (unit costs for chemical 

precipitation for this industrial category are not readily available). Total annual control costs could be 

approximately $1.1 million (based on annualizing capital costs at 7% over 20 years plus annual O&M). 
November 2010 Appendix D: Industrial Sample Discharger Analyses D-4

Pilgrim’s Pride, Live Oak Proces s ing

NPDES permit number: FL0001465 

Major/minor: Major

SIC code: 2015 (Poultry Slaughtering and Processing) 

Industrial Category: Food 

Design Flow: 1.5 mgd 

Average Flow: 1.42 mgd (based on average monthly flows from 2005 to 2010) 

Receiving Water: Suwannee River

Description

The discharger operates a poultry processing, hatching, and poultry by-product processing (into meal) 

facility. Wastewater treatment consists of dissolved air flotation, anaerobic lagoon/equalization basin, 

activated sludge (anoxic basin followed by aeration basin), secondary clarification, facultative polishing 

pond, denitrification filters, pH adjustment, and chlorination/dechlorination. Solids are aerobically 

digested and land applied by spray irrigation.

Summary of Effluent Data and Limits

Exhibit D-2 summarizes average monthly effluent data for TN and TP from June 2006 to 2010; the 

company installed new treatment technologies targeting nitrate reductions in June 2006, so data prior to 

that period is not representative of current discharge levels.

Exhibit D-2. Effluent Data Summary, Pilgrim’s Pride

Pollutant Number of Observations Average Effluent

(mg/L)1 Permit Limit2 

Total Nondetect

Total nitrogen 46 0 18 None

Total phosphorus 46 0 13 None

Source: EPA ( 2010a)

1. TN and TP effluent data from June 2006-2010. TN data represents average of average monthly values.

TP data represents value of monthly maximum values. 

2. Facility has an annual average load-based TN limit.

Incremental Controls 

EPA’s numeric TN and TP criteria are 1.87 mg/L and 0.30 mg/L, respectively. Analysis of ambient data 

for Suwannee River near the outfall indicates that the waterbody likely would not be impaired for either 

TN or TP under the rule. Thus, the discharger could receive a mixing zone for calculation of effluent 

limits which would result in effluent limits above criteria end-of-pipe. In addition, the waterbody was 

previously listed as impaired for DO and nutrients due to the presence of algal mats. FDEP delisted the 

water after acceptance of the Suwannee River Reasonable Assurance Document, which moved the water 

to EPA Category 4c, meaning no TMDL is necessary because proposed pollution control measure(s) 

provide reasonable assurance that designated uses will be restored in the future. In this instance, 

agricultural BMPs will be implemented to restore the waterbody. In this case, based on WLAs for point 

sources in TMDLs in which nonpoint sources are the main contributors to nutrient pollution, the 

discharger is likely to receive effluent limits that reflect existing loads. 
November 2010 Appendix D: Industrial Sample Discharger Analyses D-5

However, to err on the side of overestimating potential costs, EPA assumed that the discharger may need 

to implement some level of incremental control to meet effluent limits under EPA’s rule that reflect some 

level of dilution (due to a lack of existing implementation procedures for calculating effluent limits for 

nutrients in Florida, it is uncertain how to estimate available dilution ratios for the facility). Because the 

discharger is already operating activated sludge with denitrification (comparable to treatment found at a 

municipal WWTP), expanding/retrofitting the existing treatment train to advanced BNR is likely a 

feasible control option that would provide substantial reductions in effluent TN and TP concentrations. 

Based on unit costs for WWTPs, capital costs to treat 1.5 mgd with advanced BNR would be 

approximately $1.6 million and annual O&M costs would be approximately $0.2 million; annual control

costs could be approximately $0.34 million (based on annualizing capital costs at 7% over 20 years plus 

annual O&M). 
November 2010 Appendix D: Industrial Sample Discharger Analyses D-6

Imperial B rands Inc – Lake Alfred

NPDES permit number: FL0029017 

Major/minor: Minor

SIC code: 2085 (Distilled and Blended Liquors) 

Industrial Category: Food 

Design Flow: 1.4 mgd (Outfall 003)

Average Flow: 0.26 mgd (Outfall 003; average of monthly average flows)

Receiving Water: Lake Haines

Description

The facility generates a maximum of 0.163 mgd of wastewater from distillation stills, fermenters, bottling 

operations, and boiler blowdown. Under its NPDES permit, the discharger may dispose of up to 0.103 

mgd of treated wastewater onsite. Wastewater treatment consists of pH adjustment, extended aeration, 

and clarification. Treated wastewater is either spray-irrigated in 5.36 acres of sprayfield or discharged to a 

0.51-ac percolation pond. The facility also discharges a maximum of 0.06 mgd offsite to the City of Lake 

Alfred. In addition to the process wastewater, the facility produces once through and recirculating noncontact cooling water (1.4 MGD), which is combined with stormwater and discharges to Lake Haines via

Outfall 003.

Summary of Effluent Data and Limits

Exhibit D-3 summarizes average monthly effluent data for TN and TP from 2005 to 2010. 

Exhibit D-3. Effluent Data Summary, Imperial Brands – Lake Alfred

Pollutant Number of Observations Average Effluent

(mg/L)1 Permit Limit Total Nondetect

Total nitrogen 16 0 0.41 None

Source: EPA (2010a)

1. TN and TP effluent data from March 2005 to March 2010. Represents average of average monthly values. 

Incremental Controls 

Based on color data from FDEP’s IWR database (Run 40), Lake Haines is a colored lake; applicable EPA 

criteria are TN of 1.27 mg/L and TP of 0.05 mg/L. TN effluent data indicate that the facility is likely 

discharging below the applicable TN criterion. There are no TP criteria available, however, given that the 

facility is discharging noncontact cooling water it is unlikely that TP concentrations would be above the 

applicable criterion. Thus, incremental control costs are zero for this facility.
November 2010 Appendix D: Industrial Sample Discharger Analyses D-7

P ac kaging C orporation of America

NPDES permit number: FL0000281 

Major/minor: Major

SIC code: 2631 (Paperboard mills)

Industrial Category: Pulp and Paper 

Design Flow: 55 mgd

Average Flow: 55 mgd (average of average monthly flows)

Receiving Water: Withlachoochee River

Description

Current wastewater treatment system consists of a mechanical bar screen, primary clarifier, and 7 ponds 

covering 850 acres (with nutrient addition in the first and fourth ponds, coagulation at the discharge of the 

sixth pond for color reduction, and 4 anaerobic facultative ponds followed by an aeration basin). The 

facility dischargers treated effluent from Outfall 001 to Withlachoochee River. The facility treats process 

and non-process wastewater from mill manufacturing operations and stormwater. 

Summary of Effluent Data and Limits

Exhibit D-4 summarizes average monthly effluent data for TN and TP from 2005 to 2010. 

Exhibit D-4. Effluent Data Summary, Packaging Corporation of America

Pollutant Number of Observations Average Effluent

(mg/L)1 Permit Limit Total Nondetect

Total nitrogen 20 0 2.75 None

Total phosphorus 6 0 0.74 None

Source: EPA (2010a)

1. TN and TP effluent data from June 2005 to June 2010. Represents average of average monthly values. 

Incremental Controls 

The discharger is located in the North Central region with an EPA TN criterion of 1.87 mg/L and TP 

criterion of 0.03 mg/L. Based on available data in FDEP’s IWR database, the receiving water would not 

be impaired under EPA’s rule. In addition, the facility’s existing permit allows mixing zones in the 

calculation of effluent limits for dissolved oxygen, specific conductance, zinc, toxicity, pH, turbidity, 

ammonia, lead, transparency, and oil and grease. The permit specifies that the discharge is not to exceed 

20% of the receiving water flow and data from PCS indicates that on average the discharge is about 12% 

of ambient flow. Thus, given available dilution and effluent TN and TP concentrations it is likely that the 

facility would be in compliance projected effluent limits for TN but may need to reduce TP 

concentrations to as low as 0.1 mg/L (reflects approximately a 3:1 dilution ratio). EPA (2008a) provides 

unit costs for chemical addition and filtration retrofits and expansion to reduce TP concentrations to 0.1 

mg/L at WWTPs (see Exhibit 4-4). Assuming costs would be similar for this facility, capital costs could 

be approximately $17.7 million and O&M costs could be approximately $4.8 million per year; total 

annual costs could be $6.5 million (capital costs annualized at 7% over 20 years plus annual O&M). 
November 2010 Appendix D: Industrial Sample Discharger Analyses D-8

Mos aic F ertilizer, New Wales North S tac k

NPDES permit number: FL0178527

Major/minor: Major

SIC code: 2874 (Phosphatic Fertilizers)

Industrial Category: Chemicals and Allied Products

Design Flow: Not reported 

Average Flow: No discharge from Outfall 002 since 2001 

Receiving Water: George Allen Branch 

Description

The facility is responsible for an unlined closed phosphogypsum stack which received phosphogypsum 

from 1975 through 2000. The current closed stack has a base area of approximately 377 acres. The top 

surface of the closed stack is comprised of two lined emergency surge ponds constructed with 60-mil 

thick HDPE which store either surplus process water from the active system or surplus stormwater

collected within the closed stack system. Effluent is discharged to a natural wetland system prior to 

discharging to George Allen Branch through Outfall 002. 

Summary of Effluent Data and Limits

The facility has not discharged to the receiving water since 2001. Thus, there are not effluent TN and TP 

data available.

Incremental Controls 

Given the lack of discharge from the facility, it is unlikely the facility would incur incremental control 

costs associated with EPA’s rule. 
November 2010 Appendix D: Industrial Sample Discharger Analyses D-9

S t. Marks Powder, Inc . 

NPDES permit number: FL0002518

Major/minor: Major

SIC code: 2892 (Explosives) 

Industrial Category: Chemicals and Allied Products

Design Flow: 0.786 mgd 

Average Flow: 0.79 mgd (based on average monthly flows from 2005 to 2010) 

Receiving Water: Big Boggy Branch Creek 

Description

The facility manufactures small and intermediate arms propellant, and operates a 0.786 mgd design 

capacity industrial wastewater treatment system consisting of primary and secondary treatment. The 

primary treatment system includes dual high rate grit separators and a 750,000 gallon equalization tank to 

remove grit and equalize organic loading and hydraulic flows. The secondary treatment system includes 

an extended aeration unit, dual clarification, chlorination, digester, a belt filter press, four acre polishing 

pond, final chlorination with pH adjustment by carbon dioxide injection at the polishing pond discharge, 

and an eight acre spray irrigation field with overland flow to the plant ditch. 

The treated effluent is normally processed through a reclaimed water system and pumped to the Purdom 

Generating Station. When the Purdom Generating Station cannot accept the reclaimed water, the treated 

effluent is pumped to a spray field with the runoff from the spray field (Outfall 003) going into the plant 

ditch. The v-notch weir in the plant ditch is the final discharge point (Outfall 002); it discharges to Big 

Boggy Branch Creek, which in turn empties into the Wakulla River. The discharge at Outfall 002 is made 

up of runoff from the spray field (Outfall 003), non-contact cooling water and stormwater runoff. The 

facility installed carbon filters at the polishing pond to remove nitroglycerin if detected in the clarifier

effluent.

Summary of Effluent Data and Limits

Exhibit D-5 summarizes average monthly effluent data for TN from 2005 to 2010 for Outfall 002. Data 

from the facility’s fact sheet indicate that the long term average TP concentration for Outfall 002 is 0.33 

mg/L.

Exhibit D-5. Effluent Data Summary, St. Marks Powder Inc.

Pollutant Number of Observations Average Effluent

(mg/L)1 Permit Limit Total Nondetect

Total nitrogen 51 0 8.9 None

Source: EPA (2010a)

1. TN effluent data from 2005-2010 representing average of average monthly values for Outfall 002. 

Incremental Controls 

The facility is located in the Panhandle East region with an EPA TN criterion of 1.03 mg/L and TP 

criterion of 0.18 mg/L. There is not sufficient data in FDEP’s IWR (run 40) database to determine 

impairment status for Big Boggy Branch Creek. However, data from 2006 indicate that the geometric 

mean TN and TP concentrations are well below the applicable criteria (TN = 0.61 mg/L and TP = 0.019 

mg/L). Thus, it is unlikely that the discharger would be required to meet effluent limits based on meeting 
November 2010 Appendix D: Industrial Sample Discharger Analyses D-10

criteria end-of-pipe due to the likely presence of assimilative capacity in the receiving water. Given the 

relatively high average effluent TN concentrations, EPA assumed that the discharger would need to 

implement controls to significantly reduce nutrient concentrations in the effluent to meet projected 

effluent limits under the rule.

Outfall 002 may or may not contain runoff from the spray field in addition to non-contact cooling water 

and stormwater runoff. In the months in which there is no discharge from the spray field (Outfall 003), 

average TN concentrations at Outfall 002 are 0.87 mg/L which is below the applicable TN criterion. 

Although there are no data from PCS for Outfall 002 for TP to determine the average concentration 

without contributions from Outfall 003, given the range of TP values for Outfall 003 (1.7 mg/L to 0.1 

mg/L), the same relationship between concentrations and outfall contributions for TN may hold true for 

TP. Thus, assuming that the Purdom Generating Station cannot increase its reuse water demand from the 

facility, it would likely need to reduce TN and TP concentrations in Outfall 003 to prevent exceedances of 

projected effluent limits for Outfall 002 under EPA’s rule. 

The facility already has extended aeration and clarification units which could be retrofitted or expanded to 

accommodate advanced BNR treatment. Assuming average advanced BNR unit costs for WWTPs 

associated with achieving 3 mg/L TN and 0.1 mg/L TP are applicable to this facility’s wastewater, capital 

costs to treat 0.786 mgd of wastewater from Outfall 003 may be approximately $1 million and O&M may 

be approximately $110,000 per year; annual costs may be $207,000 (annualizing capital costs at 7% over 

20 years plus annual O&M). 
November 2010 Appendix D: Industrial Sample Discharger Analyses D-11

Aramark Uniform and Career Apparel

NPDES permit number: FL0178845

Major/minor: Minor

SIC code: 3582 (Commercial Laundry, Drycleaning, and Pressing Machines) 

Industrial Category: Other

Design Flow: 0.096 mgd 

Average Flow: 0.029 mgd (June 2005 through June 2010) 

Receiving Water: Stormwater drain

Existing Impairment: None

Description

The facility is the site of a groundwater remediation system for petroleum products and dry cleaning 

solvents. Discharge from the site is intermittent. Groundwater is treated by air stripping and filtration. The 

purpose of filtration is to remove suspended particulate matter in order to meet the total recoverable iron 

standard at the point of discharge. Treated effluent is discharged through Outfall D-001 to a storm drain 

then to the Class III freshwaters of Deer Creek and then to the Class III waters of the St. Johns River.

Summary of Effluent Data and Limits

There are no phosphorus effluent data in EPA’s PCS database for the facility. However, data from 2005 

and 2009 bioassay reports indicate that TP concentrations range from <0.02 mg/L to 0.041 mg/L. Exhibit 

D-6 summarizes TN data.

Exhibit D-6. Effluent Data Summary, Aramark Uniform and Career Apparel

Pollutant Number of Observations Average Effluent

(mg/L) 1 Permit Limit Total Nondetect

Total nitrogen 20 0 3.2 None

Source: EPA (2010a)

1. TN and TP effluent data from 2005 to 2010. TN data represent average of maximum monthly values; TP 

data represent average of average monthly values. 

Incremental Controls 

Given that the facility is discharging a relatively small volume treated of groundwater and is not adding 

nutrients prior to discharge (i.e., nutrients in effluent are from the groundwater), it is unlikely that 

additional controls would be needed under EPA’s rule. Thus, incremental control costs are zero for this 

discharger.
November 2010 Appendix D: Industrial Sample Discharger Analyses D-12

Gulf Power, S cholz G enerating Plant

NPDES permit number: FL0002283 

Major/minor: Major

SIC code: 4911 (Electric Services)

Industrial Category: Electric Services

Design Flow: 129.6 mgd

Average Flow: 105.5 mgd (based on average monthly flows from 2005 to 2010) 

Receiving Water: Apalachicola River

Description

The facility consists of two coal fired steam electric generating units with a total nameplate rating of 80 

MW and a gross generating capacity of 98 MW. After chlorination, the facility discharges non-contact 

once-through condenser cooling water to an onsite discharge canal which flows to Apalachicola River. 

All other industrial (ash sluice water, water softener regeneration wastewater, boiler blowdown, and air 

preheater wash) and domestic wastewater streams discharge into an onsite ash pond. Overflow from the 

ash pond discharges to the onsite discharge canal.

Summary of Effluent Data and Limits

There are no nitrogen or phosphorus effluent data in EPA’s PCS database for the facility. 

Incremental Controls 

The majority of the discharge is once-through cooling water from Apalachicola River. Thus, it is unlikely 

that the facility is increasing TN and TP loads to the receiving water. Thus, EPA assumed that the 

discharger would not likely incur incremental costs under EPA’s rule.
November 2010 Appendix D: Industrial Sample Discharger Analyses D-13

T ampa E lec tric – P olk P ower S tation

NPDES permit number: FL0043869 

Major/minor: Major

SIC code: 4911 (Electric Services)

Industrial Category: Electric Services

Design Flow: 3.1 mgd

Average Flow: 1.05 mgd (Outfall 001 based on average flows from 2005 to 2010) 

Receiving Water: Little Payne Creek

Description

The facility is an electric generating plant with a total nominal generating capacity of 920 MW comprised 

of 5 electric generating units. The facility uses a recirculating cooling pond for heat dissipation with 

makeup from groundwater and continuous discharge to Little Payne Creek via an unnamed reclaimed 

lake. The industrial wastewater treatment system treats the slag pile leachate and treated water from the 

oily water separator using an oil/water separator, dissolved air flotation tank, equalization basin, slag 

runoff retention basins, and a sand filter. The cooling reservoir receives the treated effluent from the 

onsite industrial wastewater treatment system in addition to precipitation, groundwater seepage, reject 

from the reverse osmosis unit, boiler blowdown, laboratory wastes, washdown from materials storage 

areas, stormwater runoff, and recirculating cooling water. Effluent from the cooling pond is mixed and 

aerated in a sulfuric acid mixing sump and monitored in a pH monitoring sump prior to discharge via 

Outfall 001 to the unnamed reclaimed lake. 

Summary of Effluent Data and Limits

Exhibit D-7 summarizes monthly effluent data for TN and TP from 2005 to 2010 for Outfall 001. 

Exhibit D-7. Effluent Data Summary, Tampa Electric – Polk Power Station

Pollutant Number of Observations Average Effluent

(mg/L)1 Permit Limit (mg/L)2 

Total Nondetect

Total nitrogen 14 0 1.5 2.93

Total phosphorus 46 4 0.13 None

Source: EPA (2010a)

1. TN effluent data from 2009-2010, representing average of maximum monthly values. TP effluent data 

from 2005-2010, representing average of monthly average values.

2. Represents both an average monthly and daily maximum effluent limit. Limit is based 1991 

preconstruction monitoring Conditions of Certification PA 92-32 under the Power Plant Siting Act.

 

Incremental Controls 

The facility dischargers in the West Central region with TN criterion of 1.65 mg/L and TP criterion of 

0.49 mg/L. Both TN and TP average effluent concentrations are below the applicable criteria. Thus, the 

facility would not likely incur incremental costs under EPA’s rule.
November 2010 Appendix D: Industrial Sample Discharger Analyses D-14

S t. L uc ie C ounty L andfill

NPDES permit number: FL0041483

Major/minor: Minor

SIC code: 4953 (Refuse Systems)

Industrial Category: Other

Design Flow: Not reported 

Average Flow: No discharge from 1998-2010 

Receiving Water: Canal 96

Description

The landfill is a 331 acre site that receives and processes solid waste products from residents and 

commercial properties in St. Lucie County. The leachate from the Class I sanitary landfills at the facility 

is conveyed to two lined leachate storage ponds - Ponds No. 3 and No. 4. Leachate disposal is achieved 

by natural evaporation loss, and by pumping into the sanitary sewer system controlled by Fort Pierce 

Utility Authority (FPUA.) The discharger is allowed under an agreement (discharge permit renewed 

annually) with FPUA, to discharge 70 gpm or 100,800 gpd to their sewer system. In emergency 

situations, leachate can also be pumped out directly from the ponds to private tanker trucks, to be 

transported to FPUA, or other licensed wastewater recovery or disposal facilities. The discharger is only 

permitted to discharge to surface waters when rainfall depth exceeds that of a 25-year/72-hour storm 

event at 10.19 inches; leachate discharge first flows into an onsite stormwater management system that 

comprised a 2,400 foot long drainage ditch and a 16.5 acre retention pond, before being discharged. 

Summary of Effluent Data and Limits

There are no nitrogen or phosphorus effluent data in EPA’s PCS database for the facility. 

Incremental Controls 

Because there has been no discharge in over 10 years, it is unlikely that additional controls would be 

needed as a result of EPA’s rule. Thus, incremental costs are zero for this discharger.
November 2010 Appendix D: Industrial Sample Discharger Analyses D-15

Univers al S tudios F lorida

NPDES permit number: FL0168581

Major/minor: Minor

SIC code: 7996 (Amusement Parks) 

Industrial Category: Other

Design Flow: 0.05 mgd

Average Flow: Flow data not reported since 2003 

Receiving Water: Shingle Creek

Description

The Jaws attraction is a water-based themed ride constructed in a concrete-lined basin that transports 

guests in ride vehicles shaped like boats. The facility filters the water in the attraction Lagoon and 

regulates the level of water when needed. The treatment system consists of an Actiflow filtration unit and 

draws water from the Lagoon, filters that water and returns it to the Lagoon. The filter system produces 

backwash at a rate of 15 gpm. The backwash is discharged to the City of Orlando sanitary sewer. Due to 

this change of operation the facility is reclassified as an intermittent discharger.

The facility is allowed to discharge from Lagoon to Shingle Creek after excessive accumulation of water 

in the attraction due to rainfall, to allow infrequent scheduled drawdowns of the Lagoon for maintenance, 

and for addressing emergency/unscheduled maintenance events. During maintenance events the Lagoon 

water is transferred to Pond A. The water in Pond A is then treated by aeration and tested. The water is 

then transferred to Pond C in a gravity pipe. At the completion of the Lagoon maintenance, the Jaws 

Lagoon is refilled by pumping water from Pond C. 

Summary of Effluent Data and Limits

Exhibit D-8 summarizes average monthly effluent data for TP from 2005 to 2010. There are no TN data 

in EPA’s PCS database from 2005 to 2010. 

Exhibit D-8. Effluent Data Summary, Universal Studios Florida

Pollutant Number of Observations Average Effluent

(mg/L)1 Permit Limit Total Nondetect

Total phosphorus (Outfall 002) 37 0 0.04 None

Source: EPA (2010a)

1. TP effluent data from 2005 to 2010. Represents average of maximum monthly values.

Incremental Controls 

The discharge is located in the Peninsula region with TN criterion of 1.54 mg/L and TP criterion of 0.12 

mg/L. Data from FDEP’s IWR (run 40) database indicate that Shingle Creek (WBID 3169A) would not 

be impaired under EPA’s rule for TN or TP. Thus, the discharger would likely receive dilution in 

calculation of effluent limits. Effluent TP data indicate that the facility is likely discharging below the 

applicable criterion and would not need additional controls. There are no TN data, however given the 

potential for dilution in calculating effluent limits and the fact that the facility’s fact sheet indicates that 

nutrient concentrations are extremely low and as permitted it is not reasonably expected to significantly 

impact Shingle Creek, EPA assumed that the facility would not incur incremental costs of meeting 

effluent limits for TN. 
November 2010 Appendix D: Industrial Sample Discharger Analyses D-16

Exhibit D-9 shows the potentially affected facilities and their applicable flows for the analysis of 

potential costs.

Exhibit D-9: Potentially Affected Industrial Dischargers and Applicable Flows

NPDES

No.

SIC

Code Discharger Name Discharger Type

Sample

Discharger

Nutrient 

Criteria Region

Flow

(mgd)

Chemicals and Allied Products

FL0002488 2824 Solutia Inc. Major No Panhandle West 27

FL0177130 2874 Riverview Closed 

Phosphogypsum Major No West Central 13.9* 

FL0178527 2874 IMC-Igrico Company Major Yes West Central 13.9*

FL0034657 2879 Coronet Industries Inc Major No West Central 13.9*

FL0002518 2892 St. Marks Powder Inc. Major Yes Panhandle East 0.786

FL0000884 2869 Millennium Specialty 

Chemical Minor No Peninsula 5 

FL0001040 2869 IFF Chemical Holdings Inc Minor No Peninsula 2.34*

FL0037800 2869 Montco Research Products

Inc Minor No Peninsula 0.012

FL0187313 2874 CF Industries Inc.-Tampa

Ammonia Terminal Minor No West Central 2.5

Electric Services

FL0000183 4911 FL Power Corp-Suwannee 

Riv Steam Major No North Central 342

FL0002283 4911 Gulf Power Scholz Steam Major Yes Panhandle East 129.6

FL0032166 4911 FL Power and Light-Putnam 

Steam Major No Peninsula 125

FL0002275 4911 Gulf Power Co-Crist Steam Major No Panhandle West 18

FL0025518 4911 Arvah B. Hopkins 

Generating Station Major No Panhandle East 1.87

FL0025526 4911 Sam O. Purdom Gen Station Major No Panhandle East 103*

FL0030988 4911 FL Power and Light-Martin 

County Steam Major No Peninsula 103* 

FL0032174 4911 FL Power and Light-Manatee 

Steam Major No West Central 103* 

FL0043869 4911 Tampa Electric-Polk Power 

Station Major Yes West Central 3.1

Food

FL0001465 2015 Goldkist Inc - Live Oak 

Processing Major Yes North Central 1.5

FL0175412 2033 Silver Springs Citrus/Spray

Fields Minor No Peninsula 1 

FL0105643 2033 Florida's Natural Growers Minor No Peninsula 0.8

FL0105619 2037 Cutrale Citrus Juice USA Inc. Minor No Peninsula 0.9

FL0041556 2082 Anheuser Busch - New Sod 

Farm Minor No Peninsula 1.7

FL0029017 2085 Imperial Brands Inc-Lake

Alfred Minor Yes Peninsula 1.7

FL0278076 5146 Anguilla Fish Farm Minor No Peninsula 3.67

Mining

FL0032590 1475 IMC-Agrico Co - Hopewell Major Yes West Central 5
November 2010 Appendix D: Industrial Sample Discharger Analyses D-17

Exhibit D-9: Potentially Affected Industrial Dischargers and Applicable Flows

NPDES

No.

SIC

Code Discharger Name Discharger Type

Sample

Discharger

Nutrient 

Criteria Region

Flow

(mgd)

FL0027600 1475 Mosaic Fertilizer - Ft 

Green/Payne Creek Mine Major No West Central 16* 

FL0033294 1475 Mosaic Fertilizer – Hookers 

Prairie Mine Major No West Central 16* 

FL0000655 1479 PCS Phosphate-White 

Springs, Suwannee Complex Major No Peninsula 27.8**

FL0002119 1099 Iluka Resources Inc. Minor No Peninsula 8

FL0435490 1099 Dupont North Maxville 

Expansion

Minor No Peninsula 5 

FL0101192 1422 Dolomite Inc. Minor No Panhandle West 9.7

FL0025569 1422 Dixie Lime and StoneSumterville Minor No Peninsula 6.1* 

FL0044300 1422 FL Rock Ind. - Gulf 

Hammock Minor Yes Peninsula 1.8

FL0322890 1422 Mazak Limerock Mine Minor No Peninsula 6.1*

Other

FL0178845 3582 Aramark Uniform and

Career Apparel Minor Yes Peninsula 0.096

FL0552208 3679 Honeywell International -

Sarasota

Minor No West Central 0.029

FL0171565 3699 Sprague Electronics GW

Remediation Minor No Peninsula 0.028

FL0032581 4011 CSX Transportation Inc. Minor No West Central 0.05

FL0166154 4011 Csx Transportation

Inc/Rockport Bulk Terminal Minor No West Central 1.1* 

FL0183750 4931 Indiantown Generating Plant Minor No Peninsula 0.05

FL0039951 4931 Telogia Power Minor No Panhandle East 1.1*

FL0037133 4953 Orange County Sanitary 

Landfill Minor No Peninsula 3.7

FL0037877 4953 Volusia County San Landfill Minor No Peninsula 0.11

FL0041483 4953 St. Lucie County - Landfill 

Site Minor Yes Peninsula 1.1* 

FL0001350 5171 Coastal Terminals Minor No Peninsula 0.5

FL0032441 5171 Murphy Oil USA Inc –

Freeport Terminal Minor No Panhandle West 1.1* 

FL0034622 5171 Amerada Hess Corp.-Tampa 

Terminal Minor No West Central 1.1* 

FL0123366 5171 Martin Gas Sales Inc. Minor No West Central 1.1*

FL0343498 5171 Transmontaigne Product 

Services Tampa Minor No Peninsula 1.1

FL0168581 7996 Universal Studios 

Florida/Jaws Lagoon Minor Yes Peninsula 0.05

FL0569071 9511 Usace - Kissimmee River 

ASR Pilot Project Minor No Peninsula 5 

Pulp and Paper

FL0000281 2631 Tenneco Packaging Corp. Major Yes North Central 55
November 2010 Appendix D: Industrial Sample Discharger Analyses D-18

Exhibit D-9: Potentially Affected Industrial Dischargers and Applicable Flows

NPDES

No.

SIC

Code Discharger Name Discharger Type

Sample

Discharger

Nutrient 

Criteria Region

Flow

(mgd)

FL0000221 2491 Southern Wood Piedmont 

Company Minor No Peninsula 0.022

FL0133132 2491 Universal Forest Products 

Eastern Division Minor No Peninsula 0.036* 

FL0043567 2499 Cochran Forest Products Minor No North Central 0.05

* Represents average flow for major/minor facilities in each industrial category because flow not available in 

EPA’s PCS database.

**Flow in PCS reported as 200 mgd, but flow in permit reported as 27.8 mgd; EPA used flow as reported in 

permit.
November 2010 Appendix E. Potential Effect of Nutrient Criteria on Response Indicators and Biota E-1

Appendix E . P otential E ffec t of Nutrient C riteria on R es pons e 

Indicators and B iota

The expected changes due to reduction of nutrients can be predicted with the relationships used to link the 

nutrients (TP, TN) with the response indicators [chlorophyll-a, Secchi disk transparency (SDT), 

probability of HABs] and other parameters. The expected changes in the response indicators to nutrient 

reduction can be used to infer improvements in provision of environmental goods and services and 

designated use attainment. Some of these useful relationships have been investigated for Florida 

waterbodies and are identified and described below. 

 Water column chlorophyll-a vs. TP concentrations; 

 Water clarity (e.g., SDT depth) vs. TP or TN concentrations; 

 Coverage of aquatic macrophytes (% areal coverage) vs. SDT depth; 

 Frequency of HABs vs. TP concentrations; and 

 Fish production as a function of TP. 

Brown et al. (2000) investigated the relationship between nutrients and chlorophyll-a in Florida lakes 

using data from 273 lakes collected over 10 years to develop several predictive relationships between TP 

and chlorophyll-a. A simple linear regression model between the annual average nutrient concentration 

and monthly chlorophyll-a (CHL) concentrations with reasonable fit (r2 = 0.76) was: 

log(CHL) = -0.369 + 1.052log(TP) 

This equation was essentially equivalent to a third-order polynomial regression model with a slightly 

better statistical fit (0.78) over the total phosphorus range from 3 μg/L to 160 μg/L. Thus, the simple 

regression model is useful because it holds for the range of TP concentrations observed for 93% of the 

Florida lakes (273) studied. Use of this equation can provide an estimate of the amount of chlorophyll-a 

reduction that might be predicted for a reduction in TP due to the numeric criteria in most lakes (may be 

less accurate for high levels of TP in hyper-eutrophic lakes). 

Bachmann et al. (2002) developed an equation predicting SDT as a function of nutrients (TN, TP), the 

mean depth (MD) and the percent area of bottom covered by macrophytes (PAC). Since inclusion of PAC 

data provided only a marginally better fit (r2 increased 0.03); the equation can be simplified to the 

following: 

log(SDT) = 1.13 -0.355 log(TP) – 0.274 log(TN) + 0.407 log (MD)

Use of this equation can provide an estimate of increase in SDT that might be predicted for a reduction in 

TP and TN due to the numeric numeric criteria. For mean depth, the geometric mean (2.7 m) derived 

from 318 study lakes by (Bachmann 2002) may be assumed as a generic waterbody characteristic to look 

at the increase in SDT just due to nutrients.

The maximum depth of macrophytes colonization (MDC) in Florida lakes as a function of available light 

(estimated as SDT depth) was studied by Canfield et al. (1985). They developed the empirical regression 

line predicting limiting depth of plant growth as (all units in meters):

log(MDC) = -0.42 log(SDT) + 0.41 
November 2010 Appendix E. Potential Effect of Nutrient Criteria on Response Indicators and Biota E-2

A more recent review of macrophyte biomass and trophic indicators in 318 Florida lakes found that the 

abundance of submerged aquatic macrophytes was only weakly determined by TP, TN, chlorophyll-a, or 

Secchi disk depth (Bachmann et al. 2002). The authors suggested that submerged macrophytes are absent 

only at very high chlorophyll-a concentrations in the water column. Overall, they found no predictable 

relationship between macrophyte abundance and trophic state in the lakes studied. However, they did note 

that all lakes with a water color value above 150 platinum-cobalt (PCU) units showed a distinct 

depression in both macrophyte and phytoplankton biomass. This is additional support for the separation 

of waterbodies into clear and colored classifications for numeric criteria application (75 FR 4174; January 

26, 2010) such that colored lakes have higher baseline criteria for TP and TN then clear lakes. 

Another benefit of nutrient reduction due to the implementation of the numeric numeric criteria is the 

reduced frequency of occurrence of HABs. Havens and Walker (2002) evaluated the frequency of 

occurrence of moderate (chl-a > 40 μg/L) and severe (chl-a >60 μg/L) blooms when considering target inlake TP concentrations as part of the TMDL process for Lake Okeechobee. For example, they found that 

if TP averaged < 30 μg/L then the probability of a moderate bloom was < 3% and that for severe bloom < 

1%. Therefore, application of the numeric TP criteria for clear lakes (10μg/L for clear acidic; 30 μg/L for 

clear, alkaline) could result in lowered frequency of HAB events. 

One of the commonly predicted impacts of eutrophication is a change in the fish community due to the 

increasing turbidity of the waters and altered DO regimes (Smith et al. 1999). Investigation of the 

relationship between fish production and trophic state indicators by Bachmann et al. (1996) found that 

species numbers were positively correlated to lake size but not trophic state. The authors concluded that 

trophic state is less influential to fish community composition in Florida lakes than elsewhere, since the 

lakes are shallow, lack colder bottom layers, and their major recreationally important game fish are 

warmwater species (e.g., sunfish and bass). Therefore, reduced nutrient concentrations due to the numeric 

criteria are not likely to significantly change the game fish species although there could be a reduction in 

total fish biomass.
November 2010 Appendix F. Potential Value of Improvements in Dissolved Oxygen F-1

Appendix F. Quantitative Analys is of B enefits : P otential Value of 

Improvements in DO

Section 13 presents estimates of the potential magnitude of benefits from attaining the numeric criteria 

using a water quality index (WQI) approach to link changes in total nitrogen (TN) and total phosphorus 

(TP) to the corresponding improvements in designated uses and ecological benefits, and quantify those 

benefits based on WTP for improved water quality and function. This approach only values benefits 

derived from improvements in TN and TP. However, reductions in TN and TP may also have broader 

water quality effects and indirectly reduce ambient concentrations of other WQI parameters, particularly 

dissolved oxygen (DO). 

As discussed in Section 13, nutrient levels may have an indirect effect on DO levels. As shown in Exhibit 

13-5, DO has the highest weight or importance of all the parameters in the calculation of the WQI. While 

it is possible to insert reduced TN and TP values in the WQI based on numeric criteria, there is no similar 

simple mechanism for predicting DO changes. This appendix describes an approach to incorporating 

potential changes in DO that may be associated with improved TN and TP levels in the WQI and thus 

better reflect the total environmental benefit from attaining criteria, and the potential quantitative estimate 

of total benefits.20 

F.1 Factors Affecting DO Concentration in Water 

Maximum DO concentrations in water are based on the solubility of oxygen in equilibrium with the 

atmospheric concentration of oxygen. The solubility of oxygen at equilibrium (also known as 100% 

saturation) is dependent on three primary physical and chemical factors (Wetzel, 2001):

 Temperature – the solubility of oxygen is affected nonlinearly by temperature and increases 

markedly in cold waters;

 Pressure – the solubility of oxygen is dependent on the atmospheric partial pressure at the 

waterbody surface and decreases with decreasing atmospheric pressure (i.e., saturation 

concentrations decrease with increasing altitude); and 

 Salinity – the solubility of oxygen in water is affected by salinity and salinity may therefore need 

to be considered in analyses of DO in inland saline or brackish waters. 

While these factors are critical to estimating the expected DO in the water, they are not directly linked to 

ambient nutrient concentrations and thus would be largely neutral for purposes of estimating WQI 

changes following nutrient criteria implementation. Temperature is the most influential factor (i.e., has 

the most quantitative effect) for DO concentration in lakes and flowing waters. Accordingly, some 

investigators prefer to use the temperature-corrected percent DO saturation (% DOsat) (i.e., a relative term 

indicating how much DO is present to that expected at atmospheric equilibrium) instead of, or combined 

with, the absolute DO concentration (mg/L). When DO is present in quantities > 100% saturation, the 

waterbody is termed “supersaturated.” 

Concentrations of DO in lakes and flowing water are also affected by additional factors, working either 

singly or in a combination, which may be highly significant at the local level: 

 

20 Reductions in ambient nutrient concentrations could also lead to estimated reductions in chlorophyll-a levels, although this 

parameter is currently only used in the WQI for estuaries.
November 2010 Appendix F. Potential Value of Improvements in Dissolved Oxygen F-2

 Flow velocity and turbulence – higher turbulence increases the atmospheric transfer of oxygen 

across the air-water interface and can entrain addition DO into the water. Waters below high 

waterfalls may be supersaturated for some distance downstream;

 Stratification – thermally stratified (i.e., layered) lakes will have distinctly different DO 

conditions in top and bottom layers as a function of thermal differences and the greater amount of 

BOD and microbial metabolism in the lower layer as organic carbon sinks out of the productive 

upper layer (e.g., decaying algal remains);

 Groundwater inputs – waterbodies which receive a significant hydrologic input from 

groundwater (which is often at low DO levels) may have reduced DO levels in areas where the 

groundwater discharges to the waterbody; 

 BOD – BOD is a functional water quality parameter that refers to the amount of DO that organic 

carbon and nitrogenous materials (e.g., wastewater discharges, manure inputs) could take up if 

the water sample were incubated in the laboratory under standard conditions, sealed from the 

atmosphere. BOD is generally identified by the length of the incubation (e.g. BOD5 is the amount 

of DO consumed over a 5 day period). Thus, as BOD increases, the receiving waterbody DO 

should decrease, although in flowing system the expression of lowest DO may be some distance 

downstream from the original BOD input; 

 Dissolved Organic Carbon (DOC) – dissolved organic substances in the water can also exert an 

oxygen demand such that highly colored waters (i.e., with high levels of humic and fulvic acids) 

arising in wetlands or slowing moving waterbodies will not reach fully 100% DO saturation (i.e., 

fully saturated) conditions;

 Microbial metabolism – the breakdown of organic carbon by bacterial communities consumes 

DO and may be responsible for areas of low or even absent DO at or near the sediment surface;

 Photosynthesis – oxygen generation by photosynthetic organisms (phytoplankton, periphyton, 

aquatic macrophytes) can increased local supplies of DO during daylight hours. Under eutrophic 

conditions, photosynthesis of actively growing plants can lead to DO supersaturation; and 

 Dark respiration – respiratory activities from primary producers and consumers at night reduces 

DO. The cycle of high photosynthetic activity leading to elevated DO coupled with heavy dark 

respiration at night (coupled with accompanying changes in temperature) can lead to a highly 

variable diurnal (day-night) pattern.

F.2 Response of DO to Nutrient Reduction due to Numeric Nutrient Criteria

The response of DO to changes in nutrient concentrations resulting from compliance with the numeric 

numeric criteria is likely to be complex. Changes in DO concentration may not be directly linked to 

changes in TP and TN concentrations, even though highly elevated or depressed DO levels and high 

spatial and temporal variability are considered diagnostic symptoms of eutrophication. Eutrophic waters 

often have large internal difference in DO concentrations such as supersaturated conditions in the upper 

waters, low DO in bottom waters, as well as a high diurnal variability. [Note: some degree of diurnal 

variation in DO is normal and based on the variation in water temperature over the day]. 

Reducing ambient nutrient levels would theoretically be expected to reduce the frequency and magnitude 

of extreme DO conditions and lessen the diurnal variation. However, it is very difficult to produce a 

predictive relationship between DO concentrations and/or diurnal variability and nutrients that can be 
November 2010 Appendix F. Potential Value of Improvements in Dissolved Oxygen F-3

applied to multiple waterbodies, due to potential influence of the many factors described in Section 0. 

Some of the factors that tend to “uncouple” DO concentrations from nutrient levels include: 

 DO measurements reflect instantaneous spatial and temporal conditions and not the averaged 

nutrient conditions over time;

 DO concentrations are a product of daily temperature, wind/wave action, and streamflow 

conditions which are unrelated to average nutrient concentrations; 

 The potential for resupply from atmospheric transfers often makes DO deficits very transient; 

 DO concentrations in clear and colored waterbodies could be quite different for the same amount 

of nutrients due to the influence of DOC; 

 Data on DO diurnal variability (e.g., pre-dawn minimum, mid-day maximums) will likely not be 

available for many locations due to sampling program limitations (data may be available on wellstudied lakes); and 

 Local watershed inputs that consume DO (e.g., BOD) may be present and unrelated to average 

nutrient conditions. 

Based on these difficulties, it would not be possible to predict DO improvement on the basis of reductions 

in TP and TN concentrations alone. 

F.3 Alternative Approach for Estimating DO Response to Nutrient Criteria

An alternative approach to estimating DO response to the numeric nutrient criteria would be to assume a 

DO concentration based on the trophic state achieved by the numeric criteria. Ranges of TP and TN 

concentrations that are associated with various trophic states reflecting increasing fertilization stages (i.e., 

oligotrophic, mesotrophic, eutrophic, and hyper-eutrophic) are available (Wetzel 2001). The nutrient 

criteria may generally approximately delineate the mesotrophic-eutrophic boundary, where compliance 

with the nutrient criteria (or less) would shift a waterbody to a mesotrophic condition that is fully 

supportive of its designated water uses and that avoids the adverse effects associated with severe 

eutrophication. 

Due to the various influencing factors described above, there are no recognized ranges of DO associated 

with a particular trophic state similar to those for TP and TN. However, it might be possible to a priori

assume that nutrient compliance will result in mesotrophic waterbodies where DO conditions support all 

designated water uses to a satisfactory degree. It would be necessary to assume that compliance with such 

mesotrophic conditions meets the more stringent DO requirements for Class I and III waters under FAC 

Section 62-302.530. “Criteria for surface water quality classification” of 5 mg/L DO with normal 

variability allowed. 

Thus, the alternative approach would be to simply assume a concentration of 5 mg/L for waters that 

exceed the criteria and then compare pre- and post-WQI values, with post WQI values calculated using 

changes in three parameters (DO, TN, and TP). This approach would result in an increase in the DO subindex score within the WQI when ambient DO is currently < 5.0 mg/L. This assumption is highly 

conservative since the 5.0 mg/L requirement is based on a short-term minimum DO value while the actual 

average DO levels in mesotrophic waters could be significantly higher. If ambient DO already exceeds 

5.0 mg/L, no change in the DO sub-index score would be calculated and the WQI would only reflect the 

reduced TP and TN concentrations. 
November 2010 Appendix F. Potential Value of Improvements in Dissolved Oxygen F-4

As indicated by Exhibit F-1, the current EPA sub-index for DO assumes a curvilinear relationship 

between a highest score of 100 at 10.5 mg/L DO and a lowest score of 10 at 3.3 mg/L. The substitution of 

5.0 mg/L for the DO concentration may not result in a sub-index score above 50. Based on the WQI 

definition, an overall WQI score below “50” may indicate water quality not supportive of game fish 

and/or inconsistent with an achievement of a “fishable” condition (EPA, 2009). This suggests that the DO 

sub-index curve may need to specific for Florida conditions. EPA used a FL specific curve in its WQI 

analysis found in Section 13 of this report. 

Exhibit F-1 also considers the effects of supersaturation (% DOsat > 100%) with declining water quality as 

% DO sat reach up to 275%. However, it is rare to see field readings where % DOsat > 150 % except as 

transient mid-day readings at the peak of algal photosynthesis. Further, if conditions where % DOsat > 150 

% are consistently measured, this would likely reflect physical aeration and entrainment such as below a 

waterfall or passage through a hydroelectric turbine and not be due to nutrient-related impairment.

Exhibit F-1: Freshwater Water Quality Sub-indices for DO

Parameter DO Concentration (mg/L) Subindex

DOsat ≤100%

≤3.3 10

3.3<DO<10.5 -80.29+31.88*DO-1.401*DO2

10.5≤DO 100

100% < DOsat ≤275% N/A 100 * exp((DOsat - 100) *-1.197 E-2)

275% < DOsat N/A 10

Source: Based on EPA (2009).

DOsat = dissolved oxygen saturation.

To get a better assessment of the potential for application of the assumed DO concentration of 5.0 mg/L 

to Florida waterbodies, EPA considered DO concentration data representative of ambient conditions 

(calculated as geometric annual means) for incrementally impaired waters. However, this inspection 

indicates that DO concentration data are only available for a small number of waters (16 WBIDs) for 

which current monitoring data are available and thus does not provide sufficient data for a meaningful 

application. 

However, review of the monitoring database (Exhibit F-2) indicates that sufficient data are available for 

the calculation of geometric means of WBIDs for % DOsat for many lakes (148 or 11.3% of the lake 

WBIDs) and flowing waters (148 or 10.7% of the stream WBIDs). As noted above, % DOsat provides an 

alternative parameter for relative DO availability and, if temperature is considered, may be used as a 

surrogate for compliance with minimum DO concentration requirements21. 

 

21 Absolute concentrations of DO can be back-calculated from % DOsat value through appropriate correction based on the 

ambient temperature recorded in the field. However, this would require extensive individual value-specific comparison to field 

data and is not considered critical for the purposes of this preliminary analysis.
November 2010 Appendix F. Potential Value of Improvements in Dissolved Oxygen F-5

Exhibit F-2: Summary of Available %DOsat data by Waterbody Type

Category Lake WBIDs Stream WBIDs

Total WBID Category in State 1,310 3.901

# WBIDs with %DOsat data 148 418

% WBIDs with %DOsat data 11.3% 10.7%

Total WBID Category in State identified as 

incrementally-impaired 147 330

# WBIDs with %DOsat data identified as 

incrementally-impaired 28 126

#%WBIDs with %DOsat data identified as 

incrementally-impaired 19.0% 38.2%

DOsat = dissolved oxygen saturation

WBID = waterbody identification

F.3.1 Minimum DO Criterion

There is no Florida water quality standard for % DOsat, but if the likely ambient water temperatures are

considered, it may be possible to estimate the approximate level of % DOsat that would be required to 

meet the minimum 5.0 mg/L DO criterion. 

Due to the inverse relationship with temperature, the critical period to check for DO compliance is during 

the summer. The range of average annual maximum air temperature for selected locations throughout 

Florida is shown in Exhibit F-3 and indicates a range approximately of 77 to 85o Fahrenheit (or about 25 

to 30o Celsius (About.com 2010)). Due to the shallow nature of most Florida flowing waters and lakes it 

is reasonable to assume that water temperatures are in approximate equilibrium with air temperatures. The 

corresponding full saturated (i.e., 100% DOsat) DO concentrations range from 8.26 to 7.56 mg/L (Wetzel, 

2001). To meet a DO criterion of 5.0 mg/L at these water temperatures would require a minimum % DOsat

ranging from 60 to 66%.

Exhibit F-3: Florida Annual Temperatures

Location Low Temp (°F) High Temp (°F)

Daytona Beach 61 80

Fort Lauderdale 67 84

Fort Myers 64 84

Gainesville 58 82

Jacksonville 59 79

Key West 73 83

Lakeland 64 82

Melbourne 63 81

Miami 69 83

Naples 64 85

Ocala 59 83

Orlando 62 83

Pensacola 59 77

St. Petersburg 66 82

Sarasota 62 83

Tallahassee 56 79

Tampa 63 82

West Palm Beach 67 83

Source: About.com. Florida Climate and Weather
November 2010 Appendix F. Potential Value of Improvements in Dissolved Oxygen F-6

F.3.2 DO Threshold for Meeting Beneficial Uses

In addition to the minimum DO criterion, a secondary DO threshold for Florida flowing waters is 

attainment of a DO concentration judged sufficient to meet all beneficial uses. Florida Department of 

Environmental Protection (FDEP), as part of earlier CWA Section 305(b) assessments, has used its own

water quality index to determine the quality of Florida's flowing waters, blackwaters, and springs. Index 

parameters include: water clarity, DO, BOD, nutrients, bacteria, and macroinvertebrate diversity. Looking 

only at the categorization of DO, the Florida index considers a DO value of 6.3 mg/L as fully meeting all 

uses; a DO value of 5.8 mg/L as partially meeting all uses; and a DO value of 5.3 mg/L as not meeting all 

uses (FL DEP, undated). Using the assumed Florida air and water temperature range discussed above, 

fully meeting all uses would require an approximate minimum % DOsat ranging from 73 to 83%. 

Other water quality indices explicitly include % DOsat. For example, the San Francisco Bay Water Quality 

Index indicates that % DOsat below 60% to 80% can be harmful to aquatic organisms in marine or 

brackish water environments (BISF, 2003). In freshwater situations, Said et al (2004) cited a % DOsat

value of 75% as a benchmark and Kaurish and Younos (2007) considered % DOsat values from 70% to 

79.9 % indicative of “fair” water quality and those from 80% to 89.9% indicative of “good” water quality. 

Considering these factors, EPA considers a % DOsat value of 80% an appropriate value to use assuming 

compliance with the numeric nutrient criteria will result in full attainment of all beneficial uses. Applying 

the % DOsat of 80% to the range of annual high temperatures yields DO concentrations ranging from 6.0 

to 6.6 mg/L; with a statewide average of 6.3 mg/L. This value is consistent with meeting both the Florida 

minimum DO criterion of 5.0 mg/L and reaching full attainment of beneficial uses under the stream WQI. 

F.3.3 Potential Impact of DO Threshold on WQI values

Exhibit F-4 summarizes % DOsatfor WBIDs with available data. Low DO in colored lakes and 

blackwater flowing waters is attributable to the presence of natural organic compounds and acids and not 

necessarily a function of excess nutrients (Crisman et al., 1998). Clear lakes generally meet the 80% mean 

% DOsat threshold. In contrast, flowing waters are more likely not to meet the mean % DOsat threshold of 

80%. Based on this assessment, the assumption of attaining the mean % DOsat threshold of 80% after 

nutrient reduction would not greatly improve the WQI for most lakes, but could be a significant factor in 

increasing WQI values for flowing waters. However, these judgments are based on the assuming that the 

small percentage of incrementally-impaired WBIDs for which % DOsat data are available is representative 

of the larger set for which we do not have DO data. Additional uncertainty factors are discussed below. 

Exhibit F-4: Summary of DOsat for Lakes and Flowing Waters

Category No. WBIDs with 

%DOsat data

# Incrementally Impaired 

WBIDs (DOsat < 80%)

% of WBIDs with 

DOsat <80%

Lakes

Clear 12 2 17%

Unknown (treated as clear) 9 0 0%

Colored 7 2 29%

Total 28 4 14%

Flowing Waters

Flowing waters (excludes blackwater) 117 83 71%

Blackwater 9 7 78%

Total Flowing waters 126 90 71%

DOsat = dissolved oxygen saturation

WBID = waterbody identification
November 2010 Appendix F. Potential Value of Improvements in Dissolved Oxygen F-7

F.3.4 Uncertainties Associated with Assumption of 80% DOsat following Nutrient 

Reduction

The assumption of a mean % DOsat value of 80% as the expected DO condition following attainment of 

nutrient criteria should be treated as a “best-case” scenario and not a realistic expectation for all 

incrementally-impaired waterbodies meeting the criteria. As detailed in Section 13, there are numerous 

factors that can contribute or determine the actual DO concentration in a given waterbody at any given 

time, and many of those are not related to nutrients. 

What this assumption provides is an upper bound estimate of the potential range of improvement in DO 

that might be possible following nutrient criteria implementation. However, there is no means presently 

available to estimate what fraction of this upper bound is expressed in situ in the waterbodies of interest. 

The actual level of water quality improvement arising from increasing DO is subject to significant 

uncertainty from a number of sources, including, but not limited to: 

 Lack of DO water quality monitoring data for approximately 89-90% of the Florida lakes and 

inland waters so that any extrapolation of the results of this analysis to expected potential WQI 

benefits for these uncharted waters will be based on a limited sample size

 Recognition that DOsat levels in incrementally-impaired waters may exceed 80% and may not 

realize any additional WQI improvement from criteria implementation (other than nutrient 

reductions) 

 Use of annual average summer temperature to estimate the range of maximum water temperatures

– instantaneous daily maximum temperatures would likely exceed 30o

C on some days 

 Use of average water temperatures to assess compliance with minimum DO standards (5.0 mg/L), 

instead of assessing compliance based on the number and length of instantaneous temperature 

excursions over a period 

 Recognition that there are numerous anthropogenic factors which lead to DO-consumption and 

that are not related to nutrients or which may not easily respond to a reduction in nutrients 

 Recognition that there are numerous natural factors (e.g., dissolved organic compounds (DOC)) 

which lead to DO-consumption and that are not related to nutrients or which may not easily 

respond to a reduction in nutrients 

 Exclusion of blackwater flowing waters and colored lakes in estimating DO-related benefits.

F.4 Evaluation of WQI-based Benefits with Changes in DO 

Section 13 provides WQI-based estimates of potential benefits from attaining TN and TP criteria in lakes 

and flowing waters without accounting for any associated improvements in DO. This section provides 

estimates incorporating potential improvements in DO in the WQI value.

F.4.1 Improvements in Water Quality

As a preliminary estimate, EPA assumed a “best case” scenario that incrementally impaired WBIDs for 

which DO is below 6.3 mg/L will experience an increase in DO to 6.3 mg/L as a result of attaining TN 
November 2010 Appendix F. Potential Value of Improvements in Dissolved Oxygen F-8

and TP criteria (excluding colored lakes and blackwater flowing waters, for which low DO is natural).22

As stated above, FDEP considers a DO value of 6.3 mg/L as fully meeting all beneficial uses. While the 

same number of total of miles and area is expected to improve when changes in DO are considered, large 

improvements in the WQI value results for a greater number of WBIDs when DO improvement is taken 

into account. Exhibit F-5 and Exhibit F-6 show these results. 

 

22 EPA did not estimate improvements in DO for WBIDs with current DO levels above, 6.3 mg/L as these high DO levels are not 

a result of the proposed criteria.
November 2010 Appendix F. Improvements in Dissolved Oxygen F-9

Exhibit F-5: Potential Improvements in Flowing Water and Spring Miles

Change in WQI 

Total number of WBIDs

Improved Total Miles Improved Percent of Total Miles in Analysis

Percent of Total Water 

Miles in State1

Nutrient 

Improvement

Only

Improvement

in Nutrients 

and DO 2 

Nutrient 

Improvement

Only

Improvement

in Nutrients 

and DO 2

Nutrient 

Improvement

Only

Improvement

in Nutrients 

and DO 2

Nutrient 

Improvement

Only

Improvement

in Nutrients 

and DO 2

0.01 < ΔWQI < 1.0 35 25 321 159 3.24% 1.61% 1.31% 0.65%

1.0 < ΔWQI < 5.0 84 76 897 798 9.06% 8.06% 3.65% 3.24%

5.0 < ΔWQI 47 65 284 545 2.87% 5.50% 1.15% 2.21%

Total 166 166 1,502 1,502 15.17% 15.17% 6.10% 6.10%

DO = dissolved oxygen

WQI = water quality index

1. Percentage taken out of total river, blackwater, and spring miles in Florida (24,603 miles)

2. Improvements in blackwater flowing waters do not consider a change in DO, as blackwater flowing waters are naturally impaired for DO.

Exhibit F-6: Potential Improvements in Lake Area

Change in WQI 

Total number of WBIDs

Improved

Total Square Miles 

Improved

Percent of Total Area in the 

Analysis

Percent of Total Water Area 

in the State1

Nutrient 

Improvement

Only

Improvement

in Nutrients 

and DO 2

Nutrient 

Improvement 

Only

Improvement

in Nutrients 

and DO 2

Nutrient 

Improvement

Only

Improvement

in Nutrients 

and DO 2

Nutrient 

Improvement

Only

Improvement

in Nutrients 

and DO 2

0.01 < ΔWQI < 1.0 6 5 32 31 1.70% 1.66% 0.20% 0.20%

1.0 < ΔWQI < 5.0 40 30 118 109 6.32% 5.85% 0.74% 0.69%

5.0 < ΔWQI 101 112 85 95 4.58% 5.08% 0.54% 0.60%

Total 147 147 235 235 12.59% 12.59% 1.48% 1.48%

DO = dissolved oxygen

WQI = water quality index

1. Percentage taken out of water area in Florida, including lake, coastal, beach, and estuary area (10,179,200 acres).. 

2. Improvements in colored lakes do not consider a change in DO, as colored lakes are naturally impaired for DO.
November 2010 Appendix F. Improvements in Dissolved Oxygen F-10

F.4.2 WTP for Improvements in Water Quality

Following the method described in Section 13, Exhibit F-7 shows the estimated average household WTP 

for flowing waters and Exhibit F-8 contains the average household WTP for lakes. Average annual 

household WTP for full time residents for attaining nutrient criteria may be approximately $3.61 

(midpoint estimate) for improvements in flowing waters and springs, and $0.97 (midpoint estimate) for 

improvements in lakes, when improvements in DO are taken into consideration. Part time residents have 

smaller average annual household WTP, with mid-point estimates ranging from $0.26 per household for 

improvements in lakes to $0.96 for improvements in rivers and springs. Because people are willing to pay 

more for larger improvements in water quality, average household WTP is more when both improvements 

in DO and nutrients are taken into consideration than when only TN and TP reductions are considered, 

despite the fact that the same amount of water is improved in both scenarios. 

Exhibit F-7: Potential Average Annual Household WTP for Water Quality Improvement in 

Flowing Waters in Florida (2010$)

State 

Resident 

Type

10th Percentile 50th Percentile 90th Percentile

Nutrient 

Improvement

Only

Improvement

in Nutrients 

and DO 1

Nutrient 

Improvement

Only

Improvement

in Nutrients 

and DO 1

Nutrient 

Improvement

Only

Improvement

in Nutrients 

and DO 1

Full Time

Resident $1.52 $1.97 $2.94 $3.61 $4.71 $5.63

Part Time

Winter 

Resident

$0.39 $0.50 $0.78 $0.96 $1.28 $1.53

DO = dissolved oxygen

WTP = willingness to pay

1. Improvements in blackwater flowing waters do not consider a change in DO, as blackwater flowing waters are 

naturally impaired for DO.

Exhibit F-8: Potential Average Annual Household WTP for Water Quality Improvement in 

Lakes in Florida (2010$) 

State 

Resident 

Type

10th Percentile 50th Percentile 90th Percentile

Nutrient 

Improvement 

Only

Improvement 

in Nutrients 

and DO 2

Nutrient 

Improvement 

Only

Improvement

in Nutrients 

and DO 2

Nutrient 

Improvement 

Only

Improvement 

in Nutrients 

and DO 2

Full Time

Resident $0.49 $0.54 $0.89 $0.97 $1.38 $1.49

Part Time

Winter 

Resident

$0.13 $0.14 $0.24 $0.26 $0.38 $0.41

DO = dissolved oxygen

WTP = willingness to pay

1. Improvements in colored lakes do not consider a change in DO, as colored lakes are naturally impaired for 

DO.

Exhibit F-9 and Exhibit F-10 present the estimated total state benefits for improvements in WQ in rivers 

and lakes, when improvements in DO, TN, and TP are taken into consideration. Full-time resident 

benefits range from $7.03 million (midpoint estimate) for improvements in lakes to $26.50 million 
November 2010 Appendix F. Improvements in Dissolved Oxygen F-11

(midpoint estimate) for improvements in flowing waters and springs. Seasonal resident benefits are much 

smaller, with mid-point estimates of $0.31 and $0.08 million for improvements in rivers and lakes 

respectively. Total state benefits may be approximately $26.50 million of improvements in rivers and 

springs when change in DO is considered. This is a 23% increase in benefits from the total of $21.56 

million when only nutrient improvements were taken into account. Total benefits for lakes increase from 

$6.56 million to $7.12 million (approximately 9% increase) when improvement in DO concentrations is 

taken into account. 

Exhibit F-9: Potential Total Benefits for Water Quality Improvement to Freshwater Flowing 

waters in Florida (Millions of 2010$)

State 

Resident 

Type

10th Percentile 50th Percentile 90th Percentile

Nutrient 

Improvement

Only

Improvement

in Nutrients 

and DO 1

Nutrient 

Improvement

Only

Improvement

in Nutrients 

and DO 1

Nutrient 

Improvement

Only

Improvement

in Nutrients 

and DO 1

Full Time

FL Resident $11.04 $14.27 $21.31 $26.18 $34.14 $40.81 

Part Time

Winter 

Resident

$0.13 $0.16 $0.26 $0.31 $0.42 $0.50 

Total $11.17 $14.43 $21.56 $26.50 $34.56 $41.31

DO = dissolved oxygen

1. Improvements in blackwater flowing waters do not consider a change in DO, as blackwater flowing waters are 

naturally impaired for DO.

Exhibit F-10: Estimated Total Benefits for Water Quality Improvement to Freshwater Lakes 

in Florida (Millions of 2010$)

State 

Resident 

Type

10th Percentile 50th Percentile 90th Percentile

Nutrient 

Improvement

Only

Improvement

in Nutrients 

and DO 2

Nutrient 

Improvement

Only

Improvement

in Nutrients 

and DO 2

Nutrient 

Improvement

Only

Improvement

in Nutrients 

and DO 2

Full Time

FL Resident $3.58 $3.91 $6.48 $7.03 $10.02 $10.83

Part Time

Winter 

Resident

$0.04 $0.05 $0.08 $0.08 $0.12 $0.13

Total $3.62 $3.96 $6.56 $7.12 $10.14 $10.96

DO = dissolved oxygen

1. Improvements in colored lakes do not consider a change in DO, as colored lakes are naturally impaired for 

DO.

F.5 References

About.com. 2010. Florida’s Climate and Weather - Annual Average Temperatures for Select Locations. 

Available electronically at: http://goflorida.about.com/od/floridaweather/ss/weather_2.htm 

Bay Institute of San Francisco (BISF). 2003. San Francisco Bay Water Quality Index. Indicator Analysis 

and Evaluation. Cude, C.G. 2001. Oregon Water Quality Index: A Tool for Evaluation Water Quality 

Management Effectiveness. J. Am. Water Resourc. Assoc. 37:125-137. 
November 2010 Appendix F. Improvements in Dissolved Oxygen F-12

Crisman, T.J. Chapman, L.J. and C.A. Chapman. 1998. Predictors of seasonal oxygen levels in small 

Florida lakes: the importance of color. Hydrobiologia 368:149-155. 

Cude, C.G. 2001. Oregon Water Quality Index: A tool for evaluation water quality management 

effectiveness. J. Am. Water Res. Assoc. 37: 125-137. 

Florida Department of Environmental Protection (undated) Presentation on 305(b) methodology 

electronically accessible at: 

http://www.sarasota.wateratlas.usf.edu/upload/documents/305b_methodlogy.pdf 

Kaurish, F.W. and T. Younos. 2007. Developing a standardized water quality index for evaluating surface 

water quality. J. Am. Water Res. Assoc. 43:533-545. 

Said, A., Stevens, D. and G. Sehlke. 2004. An innovative index for evaluating water quality in flowing 

waters. Environ. Management 34:406-414. 

U.S. Environmental Protection Agency. 2002. Estimate of National Economic Benefits Using the 

National Water Pollution Control Assessment Model to Evaluate Regulatory Options for 

Concentrations Animal Feeding Operations. (EPA-821-R-03-009). U.S. EPA, Office of Water, 

Washington, D.C. December 2002. 

U.S. Environmental Protection Agency. 2009. Environmental Impact and Benefits Assessment for Final 

Effluent Limitations Guidelines and Standards for the Construction and Development Category 

(EPA-821-R-03-012). U.S. EPA, Office of Water, Washington, D.C. November 2009. 

Wetzel, R. 2001. Limnology – Lake and River Ecosystems. 3rd edition. Academic Press, NY.