## PROPOSED

TOTAL MAXIMUM DAILY LOAD (TMDL)

For

Dissolved Oxygen and Nutrients

In The Everglades

(WBIDs 3252A, 3252B, 3252C, 3260, 3263, 3265B)

Hendry, Broward, Palm Beach,

and Dade Counties, Florida

P r e p a r e d b y :

U S E P A R e g i o n 4

6 1 F o r s y t h S t r e e t S W

A t l a n t a
, G e o r g i a 3 0 3 0 3

S e p t e m b e r 2 0 0 7i TABLE OF CONTENTS

⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯

1 INTRODUCTION.............................................................................................................. 1

1.1 Purpose of Report.......................................................................................................... ... 4

1.2 Identification of Im paired Waterbodies ........................................................................... 5

1.2.1 Everglades Agricultural Area....................................................................................... 5

1.2.2 Everglades Protection Area ....................................................................................... 13

2 STATEMENT OF WATER QUALITY PROBLEM................................................... 17

2.1 Impaired Waterbody Segments ...................................................................................... 18

2.2 Pollutants of Concern...................................................................................................... .... 18

2.3 Source of Pollutants ....................................................................................................... 19

3 WATER QUALIT Y STANDARDS ............................................................................... 22

3.1 Nutrient Criteria .......................................................................................................... ... 23

3.1.1 Nutrient Criteria fo r Class III Waters........................................................................ 23

3.1.2 Nutrient Criteria for Class IV Waters ........................................................................ 23

3.2 Dissolved Oxygen Criteria............................................................................................. 23

3.2.1 DO Criteria for Class IV Canals................................................................................ 23

3.2.2 DO Criteria for Class III Canals................................................................................ 24

3.2.3 DO Site Specific Alte rnative Criteria......................................................................... 24

4 TARGET IDENTIFICATION ....................................................................................... 26

4.1 Basis and Rationale For Phosphorus Targets................................................................. 26

4.2 Phosphorus Target Development ................................................................................... 26

4.2.1 Everglades Protection Area ....................................................................................... 26

4.2.2 Everglades Agricultural Area..................................................................................... 27

4.3 DO Target.................................................................................................................. ..... 29

5 WATER QUALIT Y RESULTS...................................................................................... 31

6 SOURCE ASSESSMENT ............................................................................................... 33ii 6.1 Background Loads.......................................................................................................... 3 3

6.2 Permitted Point Sources ................................................................................................. 33

6.2.1 Traditional Point Sources........................................................................................... 33

6.2.2 Stormwater Treatment Areas (STAs).......................................................................... 33

6.2.3 Municipal Separate Storm Se wer System Permittees................................................. 34

6.3 Nonpoint Sources ........................................................................................................... 35

6.3.1 Agriculture.................................................................................................................. 36

7 TMDL ALLOCATION ................................................................................................... 37

7.1 Allocation................................................................................................................. ...... 37

7.2 Load Allocation (LA)..................................................................................................... 37

7.3 Wasteload Allocation (WLA) ........................................................................................ 38

7.4 Margin of Safety........................................................................................................... .. 38

7.5 Seasonal Variability ....................................................................................................... 40

8 TMDL IMPLEMENTATION ........................................................................................ 40

9 REFERENCES................................................................................................................. 41

APPENDIX B: Draft 2006 impairment determinations by FDEP........................................ 52

APPENDIX C: Indicators of phosphorus impairment in the EPA....................................... 54

APPENDIX D: Calculation of current water quality conditions .......................................... 56

APPENDIX E: PLOAD model, EMC values and results....................................................... 58

LIST OF TABLES

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Table 1. Planning Unit and Basin Group for Impaired WBIDs..................................................... 4

Table 2. Land use classification series for WBIDs. Data are for 1999......................................... 9

Table 3. Water Year 2002-2006 Summary of Flows, TP Loads, and Average TP Concentrations into the Refuge at WBID 3252B (WCA-1 North Sector) (from SFWMD and FDEP, 2007). ... 14

Table 4. Water Year 2002-2006 Summary of Flows, TP Loads, and Average TP Concentrations intoiii EPA WBID 3265B (WCA-2 West Sector) (from SFWMD and FDEP, 2007). ................... 16

Table 5. FDEP impairment determinations for Everglades WBIDs............................................ 18

Table 6. Years with the lowest annual STA outfl ow TP concentration across STAs from 1995 to 2006 (Pietro et al., 2007). .................................................................................................... . 28

Table 7. Annual STA inflow TP loads based on PLR of 1.0 g/m 2 /year. ..................................... 29

Table 8. WY2002 to WY 2006 TP concentration and load for EAA and EPA WBIDs.............. 32

Table 9. Permitted Facilities Discharging into impaired EPA WBIDs. ...................................... 34

Table 10. MS4 Permitees in the Drainage Basins of Impaired WBIDs....................................... 35

Table 11. TMDL allocation for Total Phosphorus ...................................................................... 39iv ABBREVIATIONS

Ac-ft acre-feet AW FWMC Farm area-weighted flow-weighted mean concentration BMP Best Management Practices DO Dissolved Oxygen EAA Everglades Agricultural Area ECP Everglades Construction Project

EMC Event Mean Concentration EPA Everglades Protection Area

FAC Florida Administrative Code FDEP Florida Department of Environmental Protection FWMC Flow-weighted mean concentration HUC Hydrologic Unit Code

LA Load Allocation Lb/day pounds per day MOS Margin of Safety MS4 Municipal Separate Storm Sewer Systems

mt metric ton NPDES National Pollutant Discharge Elimination System OFW Outstanding Florida Water PLOAD Phosphorus Load model PLR phosphorus loading rate

PLRG Pollutant Load Reduction Goal ppb parts per billion (micrograms per liter) R-EMAP Regional Environmental Monitoring and Assessment Project SFER South Florida Environmental Report SFWMD South Florida Water Management District SSAC Site-Specific Alternative Criterion

STA Stormwater Treatment Area TBEL Technology-based Effluent Limit TMDL Total Maximum Daily Load TN Total Nitrogen TP Total Phosphorus USEPA United States Environmental Protection Agency WBID Water Body Identification

WCA Water Conservation Area

WLA Wasteload allocation WMD Water Management District WQBEL Water Quality Based Effluent Limit WY Water Year (May to April)v SUMMARY SHEET

1. Florida 1998 303(d) Listed Waterbody Information

WBID Segment Name Classification Constituent County HUC

3265B* (3265F, 3265H) Everglades Water

Conservation Area 2A

Southwest Perimeter 3F Nutrients, DO, Fecal Coliform**,

Cadmium** Broward,

Palm Beach 03090202

3252B Everglades Water

Conservation Area 1 North Sector (Arthur

R. Marshall

Loxahatchee National Wildlife Refuge 3F Nutrients, DO, Fecal Coliform**, Total Suspended

Solids** Palm Beach 03090202

3263 S-7 Basin 3F Nutrients, DO, Turbidity** Palm Beach 03090202

3260 S-8 Basin 3F Nutrients, DO Palm Beach, Hendry 03090202

3252A Knight’s Farm Field 1 3F Nutrients Palm Beach 03090202

3252C ACME North Sector (formerly Knight’s Farm Field 3) 3F Nutrients Palm Beach 03090202

* This WBID is included on the 1998 303(d) list and the 1998 Consent Decree. It was redrawn and renamed by FDEP in 2006. New names are in parentheses.

** EPA has determined that TMDLs are not needed for these constituents, as water quality standards are currently achieved in the waterbody.

2. Water Quality Standards :

Class III: Waters. Recreation, propagation and maintenance of a healthy, wellbalanced population of fish and wildlife. Class IV Waters: Agricultural water supply.

Dissolved Oxygen Applies to Class III canals within the Everglades Agricultural Area (EAA) and Everglades:

DO (62-302.530(31)): Shall not be less than 5.0 mg/l. Normal daily and seasonal

fluctuations above these levels shall be maintained. Applies to the marsh throughout the Everglades Protection Area (EPA): DO Site Specific Alternative Criterion (SSAC): DO concentration can vary with water temperature and time of day to reflect natural diurnal biological processes. Applies to Class IV canals within the EAA:

DO (62-302.530(31)): Shall not average less than 4.0 mg/l in a 24-hour period and shall never be less than 3.0. Normal daily and seasonal fluctuations above these levels shall be

maintained.

Nutrients Applies to Class IV canals within the EAA and Class III waters:

Nutrients (62-302.530(48)(a)): The discharge of nutrients shall continue to be limited as needed to prevent violations of other standards contained in this chapter. Man induced nutrient enrichment (total nitrogen and total phosphorus) shall be considered degradation invi relation to the provisions of Section 62-302.300, 62-302.700, and 62-4.242, FAC. Applies to Class III canals of the EAA and the EPA: 62-302.530(48)(b) In no case shall nutrient concentrations of a body of water be altered so as to cause an imbalance in natural populations of aquatic flora or fauna. Applies to the marsh throughout the Everglades Protection Area

. The TP criterion is a long-term geometric mean of 10 ppb, as specified in Section 62- 302.540, FAC.

Natural Conditions ( 62-302.200(15)) : Florida’s water quality standards provide a definition of natural background:

“Natural Background” shall mean the condition of waters in the absence of man-induced

alterations based on the best scientific info rmation available to the Department. The establishment of natural background for an altered waterbody may be based upon a similar unaltered waterbody or on historical pre-alteration data

.

Florida’s water quality standards (62-302.300(15)) also provide that:

Pollution which causes or contributes to new violations of water quality standards or to continuation of existing violations is harmful to the waters of this State and shall not be allowed. Waters having water quality below the cr iteria established for them shall be protected and enhanced. However, the Department shall not strive to abate natural conditions.

3. TMDL Targets

Nutrients: The TMDLs target Total Phosphorus (T P) because TP is the limiting nutrient for the Everglades. For the Everglades Prot ection Area WBIDs, the numeric TP criterion of 10 ppb geometric long-term average is app lied at inflows as the equivalent annual maximum flow-weighted discharge limit of 16 ppb. For Everglades Agricultural Area (EAA) WBIDs, a TP concentration target is derived that is necessary to protect the downstream waters of the Everglades. This 100 ppb target is determined to be the concentration required at Stor mwater Treatment Area (STA) inflows in order to result in the STA outflow of 16 ppb. The 100 ppb requi rement is applied to Class III canals within the EAA. In addition, in order to protect Class III waters, this 100 ppb TP requirement is applied within the EAA to Cl ass IV agricultural pumps at the point of discharge into Class III waters. The 100 ppb-based TMDL within the EAA should protect the designated use of the Class III canal s within the EAA as well as diminish the contribution to water quality impairments in th e downstream waters of the Everglades.

Dissolved Oxygen: TMDLs for dissolved oxygen are addressed through controlling nutrients. All of the water conveyances with in the EAA are artificial canals that were constructed for flood control and water suppl y purposes. Due to gr oundwater influence, it may not be possible to consistently meet the present statewide DO standard for Class IV waters (not less than 3.0 mg/L and 24- hour average not less than 4.0 mg/L), even after controlling pollutant loadings to t hose waters. For the Everglades marsh, improvement in phosphorus condition such that the waterbody no longer is impaired for

nutrients should result in attainment of the DO SSAC.vii 4. TMDL allocation for Total Phosphorus

WBID Water

Class TMDL 1,2,3
(ppb) WLA (ppb) LA (ppb) 2,3 MOS Percent

Reduction 4

Everglades Agricultural Area or ACME Improvement District

Class III 100 0 100 Implicit 0%

3263 (S-7)

Class IV 100 0 100 (at inflow to Class III canal) Implicit 0%

Class III 100 0 100 Implicit 0%

3260 (S-8)

Class IV 100 0 100 (at inflow to Class III canal) Implicit 0%

Class III 100 0 100 Implicit 41% 3252A (Knight’s

Farm Field 1) Class IV 100 0 100 (at inflow to Class III canal) Implicit 41%

3252C (ACME North Sector) Class III 100 0 100 Implicit 13%

Everglades Protection Area

3265B (3265F, 3265H; WCA2A Southwest Sector) Class III 16 (see note 5) 16 Implicit 56%

3252B (Refuge North Sector) Class III 16 (see note 5) 16 Implicit 82%

Notes:

1. TMDL expressed as an annua l load is calculated by multiplying 16 ppb times the annual flow and conversion factors. To express th e TMDL as a daily load, the annual load is divided by 365 days per

year.

2. 100 ppb based on STA inflow need of 100 ppb to meet STA effluent of 16 ppb annual maximum.

3. Allocation given to Class IV canals is necessary to protect the downstream Class III waters and should be implemented and monitored at the point of entry into Class III waters.

4. Based on WY2002-2006 annual averages.

5. Assumes all flow into this WBID is treated by STAs with NPDES permits. TMDL is to be applied on an annual basis by multiplying 16 ppb times the annual flow and conversion factors.

5. Endangered Species (yes or blank): Yesviii 6. USEPA Lead on TMDL (USEPA or blank): USEPA

7. TMDL Considers Point Source, Nonpoint Source, or both : Both

8. Major NPDES Discharges to EPA WBIDs

9. MS4 Allocation. MS4 Permitees in th e Drainage Basins of Impaired WBIDs

County Permitee Permit ID Number MS4 Type TP target (ppb)

Palm Beach Village of Wellington FLS000018 Phase I 100

Note: The MS4 is responsible for controlling polluta nt loads from the urban areas within its jurisdiction

. Facility NPDES Permit Impacted

WBID TP (ppb)

STA-1E FL0304549 3252B

STA-1W FL0177962-001 3252B 16 applied at all

inflows to

WBID

STA-2 FL0177946-001 3265B

STA-3/4 FL0300195-001 3265B 16 applied at all

inflows to

WBIDEverglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

1 

## 1 INTRODUCTION

Section 303(d) of the Clean Water Act requires each state to list those waters within its boundaries for which technology based effluent limitations are not stringent enough to protect any water quality standard applicable to such waters. Listed wate rs are prioritized with respect to designated use classifications and the severity of pollution. In accordance with this prioritization, states are required to develop Total Maximum Daily Loads (TMDLs) for those water bodies that are not meeting water quality standards. The TMDL pr ocess establishes the allowable loadings of pollutants for a waterbody based on the relationshi p between pollution sources and in-stream water quality conditions, so that states can establish wa ter quality based controls to reduce pollution from both point and non-point sources and restore and maintain the quality of their water resources (United States Environmental Protection Agency [USEPA], 1991). The TMDLs described in this report are being proposed pursuant to USEPA co mmitments in the 1998 Consent Decree in the Florida TMDL lawsuit (Florida Wildlife Federation, et al. v. Carol Browner, et al., Civil Action No. 4: 98CV356-WS, 1998).

The Florida Department of Environmental Protec tion (FDEP) developed a statewide, watershedbased approach to water resource management. Under the watershed management approach, water resources are managed on the basis of natural boundaries, such as river basins, rather than political

boundaries. The state’s 52 basins are divided into 5 groups. Water quality is assessed in each group on a rotating five-year cycle. The Everglades Basi n is located in group 5. FDEP established five water management districts (WMD) responsib le for managing groundwater and surface water supplies in the counties encompassing the districts. Waters within the Everglades region that are addressed in this TMDL report are managed thr ough the South Florida Water Management District (SFWMD).

For the purpose of planning and management, the WM Ds divided the districts into planning units defined as either an individual primary tributar y basin or a group of adjacent primary tributary basins with similar characteristics. These pla nning units contain smaller, hydrological based units called drainage basins, which are further divided into “water segments”. Each segment is assigned a unique Waterbody IDentification (WBID) number. A water segment usually contains only one unique waterbody type (lake, canal, etc.).

The locations of WBIDs in the Everglades are s hown in Figure 1. The WB IDs that have nutrient TMDLs due September 30, 2007 as required by the C onsent Decree are shown in Figure 2. This TMDL report addresses only those Everglades TMDLs that are due by September 30, 2007.

The TMDLs are based on current available informati on. These TMDLs can be revised in the future, as the science and knowledge of the Everglades ecosy stem improves. Any significant changes to the TMDLs will be required to go through the public process.Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

2 Figure 1. Location of Everglades WBIDs (from SFWMD and FDEP, 2007).Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

3 Figure 2. Due dates required in the 1998 Consent Decree for nutrient TMDLs in the Everglades.Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

4 1.1 Purpose of Report

This document presents TMDLs for pollutants cont ributing to 1998 listed impairments (nutrients and Dissolved Oxygen (DO)) in the Everglades Protec tion Area (EPA) or the Everglades Agricultural Area (EAA). These areas were identified by FDEP in 1998 as impaired by nutrients or DO. In 2005 FDEP revisited the impairment issue and again determ ined in their draft verifi ed list that these areas are impaired for nutrients and DO (see Table 1). Because phosphorus is the limiting nutrient in the Everglades, it is the nutrient targeted in thes e TMDLs. Pollutant load reductions to Total Phosphorus (TP) should result in reduced nutrient loadings and ultimately achieve the designated use and not contribute to waterbody impairment.

Table 1. Planning Unit and Basin Group for Impaired WBIDs

WBID Segment Name Planning Unit Basin Group

3265B* (3265F, 3265H) Everglades Water

Conservation Area 2A

Southwest Perimeter Everglades Water

Conservation Area 2 5

3252B Everglades Water

Conservation Area 1 North Sector (Arthur

R. Marshall

Loxahatchee National Wildlife Refuge) Everglades Water

Conservation Area 1 5

3263 S-7 Basin Everglades Agricultural Area 5

3260 S-8 Basin Everglades Agricultural Area 5

3252A Knight’s Farm Field 1 Everglades Agricultural Area 5

3252C* ACME North Sector (formerly Knights Farm Field 3) Everglades Water

Conservation Area 1 5

* This WBID is included on the 1998 303(d) list and the Consent Decree. It was redrawn and renamed by FDEP in 2006. New names are in parentheses.Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

5 1.2 Identification of Impaired Waterbodies

1.2.1 Everglades Agricultural Area

The EAA is located on the southern tip of La ke Okeechobee and is one of the most productive agricultural regions in the State. Over 505,000 acres of the EAA are under production with sugar cane that accounts for over 80 percent of total crop coverage. Farmers also grow vegetables, sod, and rice during the winter months. Several major public canals (Miami, West Palm Beach, Hillsboro, and North New River) had been built by the 1920’s to drain and irrigate the EAA. These canals underwent major renovations and became part of the Central and Southern Florida Project (C&SF Project). These canals are Class III waters (see section 3). They are included on the 1998 303(d) list as impaired for nutrients and DO.

Florida’s 1994 Everglades Forever Act (EFA) required EAA landowners to reduce the total phosphorus in the runoff from their land by 25 percen t basin-wide (Rule 40E-63). The green labels in Figures 3, 4, 6 and 8 identify the specific farm basins permitted to discharge under this rule. Landowners are implementing Best Management Practi ces (BMPs) to manage water, sediments, and nutrients that balance water quality improvements and agricultural productivity. From water year 1996 to 2006 EAA Basin reductions were better than the 25% annual reduction required by the EFA.

There are three WBIDs in the EAA that are included on the 1998 303(d) list as impaired for nutrients and DO that have TMDLs due by Sept ember, 30, 2007 as required by the 1998 Consent Decree: WBID 3260 (S-8 Basin); 3263 (S-7 Basin); and 3252A (Knight’s Farm Field 1) (Figures 2 and 3). Land cover for all of th ese WBIDs is predominately agriculture (Table 2). All of these

WBIDs drain into Stormwater Treatment Areas (STAs, wetlands constructed and managed to remove phosphorus from stormwater) which discha rge into the downstream Everglades Protection Area (EPA). The EAA WBID delineations were drawn by FDEP in the 1980s. They do not accurately reflect current farm basins or drainages (Figures 3 to 9).Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

6 Figure 3. Location of WBIDs within the EAA (fr om SFWMD). WBIDs outlined in orange are the subject of this report. Black lines delineate farm basins. Green labels indicate permits under Florida EAA BMP Rule (Chapter 40E-63 F.A.C.).Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

7 1.2.1.1 WBID 3263

WBID 3263 (S-7 basin ) is in Palm Beach County within the EAA and is about 51,480 acres in area (Figures 4 and 5). There are th ree C & SF Project canals in the basin: the North New River Canal,

the L-6 borrow canal and the L-5 borrow canal. The North New River Canal connects Lake Okeechobee to Everglades Water Conservation Areas (WCAs) 2 and 3. The connection to WCA2 is by the S-7 pump station, and the connection to WCA3 is by the S-150 pump. Project control

structures that affect flow in the S-7 basin include S-7, S-2 (connects the North New River canal to Lake Okeechobee), S-150, and S-351 (a gated spillw ay on Lake Okeechobee) (Cooper 1989). Most of the farm discharges within this WBID are treat ed by STA 3/4 prior to discharge into the EPA. The discharges from about 1000 acres in the northeast corner are treated by STA 2, and the discharges from about 5800 acres in the southwest corner are discharged westward to the Miami

Canal. Land cover in the S-7 basin is almost en tirely agriculture (95%, Table 2). Water, wetlands and forest account for only about 2% of the land use. There are only 30 acres of urban or residential

land. The basin also includes the future 8600 acr e Compartment B STA expansion, projected for 2010. There are 12 private pumps that discharge st ormwater from agricultural land into the North New River Canal (Figure 4). The North New River Canal is designated as Class III water (recreation, propagation and maintenance of a h ealthy, well-balanced population of fish and wildlife), while the smaller canals in agricultural lands that have been constructed and managed by private interests are all Class IV canals (agricu ltural water supply). There are no NPDES permitted

facilities within this WBID.

Figure 4. WBID 3263, S-7 basin (from SFWMD). Black lines delineate farm basins. Green labels indicate permits under Florid a EAA BMP Rule (Chapter 40E-63 F.A.C.).

### Copyrighted page/s removed. Copyrighted ma terial is not available in Regulations.gov since it may not be reproduced without consent of the copyright holder.

Contact the EPA Docket Center’s P ublic Reading Room to view or receive a copy of this document.

Requests for copies may be made as follows:

In person/writing: Environmental Protection Agency, Docket Center 1301 Constitution Ave NW, 2822T, Room 3334 Washington, DC. 20004

Telephone:
202-566-1744

Fax:
202-566- 9744

Email: docket-customerservice@epa.govEverglades – Nutrient Total Maximum Daily Load US EPA Region 4 September 20079Table 2. Land use classification series for WBIDs. Data are for 1999.WBIDUrban &Residential(1100-1390)Commercial,Industrial,Public (1400,1500, 1700,1800,1900)Agriculture(2000)Rangeland(3000)Forest(4000)Water(5000)Wetlands(6000)Barren &Extractive(1600,7000)Transportation& Utilities(8000)TOTAL(acres)3252A0 167 21,562 179 0 326 68 98 0 22,3323252B0 0 0 0 0 296 17,364 65 10 17,7343252C3,169 1,602 1,885 998 81 554 230 55 240 8,81332600 0 55,787 29 0 344 27,047 709 8 83,924326330 499 48,865 97 226 387 270 531 616 51,5223265F0 0 0 0 0 144 7,411 113 323 7,9913265H0 0 0 0 0 143 58,876 68 35 59,121WBIDUrban &Residential(1100-1390)Commercial,Industrial,Public (1400,1500, 1700,1800, 1900)Agriculture(2000)Rangeland(3000)Forest(4000)Water(5000)Wetlands(6000)Barren &Extractive(1600,7000)Transportation& Utilities(8000)TOTAL(%)3252A0% 0% 97% 1% 0% 1% 0% 0% 0% 100%3252B0% 0% 0% 0% 0% 2% 98% 0% 0% 100%3252C36% 18% 21% 11% 1% 6% 3% 1% 3% 100%32600% 0% 66% 0% 0% 0% 32% 1% 0% 100%32630% 1% 95% 0% 0% 1% 1% 1% 1% 100%3265F0% 0% 0% 0% 0% 2% 93% 1% 4% 100%3265H0% 0% 0% 0% 0% 0% 100% 0% 0% 100%Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

10 1.2.1.2 WBID 3260

WBID 3260 (S-8 basin) encompasses 84,431 acres w ithin the EAA and is located in Hendry and Palm Beach Counties (Figures 5 and 6). There ar e two C&SF Project canals in the basin: the Miami

Canal and the L-4 Borrow Canal. The Miami Ca nal connects Lake Okeechobee to Everglades WCA 3A. The connection to WCA 3A is by the S-8 pum p station, and the connection to Lake Okeechobee is by the S-3 pump. Project control structures thataffect flow in the S-8 basin include S-3, S-8, S354 (a gated spillway on Lake Okeechobee), and G-88 (a culvert at the intersection of L-3 and L-4 in northwestern WCA3A) (Cooper 1989). Stormwater from this WBID is treated in STA3/4 prior to discharge into the EPA. Land cover in the S-8 basin is primarily agriculture (66%, Table 2), although the basin also includes the Rotenberg er Wildlife Management Area (a portion of Everglades managed by the State of Florida), a nd the future STA expansion (Compartment C, 8185 acres). These wetlands areas account for 32% of the basin. Several private pumps discharge stormwater from agricultural land toward or into the Miami Canal (Figure 6). The Miami and L-4 canals are designated as Class III waters, while smaller canals within the WBID are Class IV canals that drain agricultural lands. There are no NPDES permitted facilities within this WBID.

Figure 6. WBID 3260, S-8 basin (from SFWMD). Black lines delineate farm basins and green labels are permits under Florida EAA BMP Rule (Chapter 40E-63 F.A.C.).

### Copyrighted page/s removed. Copyrighted ma terial is not available in Regulations.gov since it may not be reproduced without consent of the copyright holder.

Contact the EPA Docket Center’s P ublic Reading Room to view or receive a copy of this document.

Requests for copies may be made as follows:

In person/writing: Environmental Protection Agency, Docket Center 1301 Constitution Ave NW, 2822T, Room 3334 Washington, DC. 20004

Telephone:
202-566-1744

Fax:
202-566- 9744

Email: docket-customerservice@epa.govEverglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

12 Figure 8. WBID 3252A, Knight’s Farm Field 1 (from SFWMD). Black lines delineate farm basins. Green labels indicate perm its under Florida EAA BMP Rule (Chapter 40E63 F.A.C.).

1.2.1.4 WBID 3252C

WBID 3252C (ACME Basin North Sector) is about 8813 acres to the east of the Refuge. Land use in this WBID is a mix of primarily urban and re sidential (36%), agriculture (21%), and commercial and industrial (18%). Stormwater from this WBID is treated in STA 1E prior to discharge into the Refuge. This basin includes the Village of Wellington, which has a MS4 permit (FLS000018). There are no continuous discharge municipal or industrial NPDES permitted facilities within this

WBID.

### Copyrighted page/s removed. Copyrighted ma terial is not available in Regulations.gov since it may not be reproduced without consent of the copyright holder.

Contact the EPA Docket Center’s P ublic Reading Room to view or receive a copy of this document.

Requests for copies may be made as follows:

In person/writing: Environmental Protection Agency, Docket Center 1301 Constitution Ave NW, 2822T, Room 3334 Washington, DC. 20004

Telephone:
202-566-1744

Fax:
202-566- 9744

Email: docket-customerservice@epa.govEverglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

14 may be diverted around the STAs (v ia the G300 and G301 structures) into the Refuge. Annual flow, total phosphorus loads, and flow-weighted mean TP c oncentrations at structur es discharging into the Refuge at WBID 3252B are summarized in Table 3 for the most recent five water years (WY2002- WY2006).

All water discharged into the Refuge in this WBID is to be treated by STA 1E or STA 1W. These STAs have NPDES permits (FL0304549 and FL 0177962-001, respectively). The STA1W permit predates Florida’s 2005 adoption of the 10 ppb numeric TP criterion for the Ev erglades, and as such it does not reflect current water quality standards, nor does it contain revised discharge limits. FDEP has stated that they intend to reissue this pe rmit to reflect the 10 ppb criterion, with appropriate discharge limits. A wasteload allocation for these permits is included in this TMDL document.

Table 3. Water Year 2002-2006 Summary of Flows, TP Loads, and Average TP Concentrations into the Refuge at WBID 3252B (WCA-1 North Sector) (from SFWMD and FDEP, 2007).

Year Parameter G300+G301

untreated G251 STA

1W outflow G310 STA

1W outflow S362 STA

1E outflow

WY 2002 Flow (1000 ac-ft) 11 7 261

TP Load (mt) 1.6 0.17 12.0

FWMC (ppb) 118.3 19.8 37.3
WY 2003 Flow (1000 ac-ft) 10 97 499 TP Load (mt) 2.5 5.5 33.4 FWMC (ppb) 201.9 44.1 54.2
WY 2004 Flow (1000 ac-ft) 17 55 243 TP Load (mt) 3.1 3.0 14.1 FWMC (ppb) 147.9 44.2 46.9
WY 2005 Flow (1000 ac-ft) 69.1 62.85 320.5 15.9 TP Load (mt) 27.0 7.8 38.7 7.6 FWMC (ppb) 317.1 100.4 97.8 387.3
WY 2006 Flow (1000 ac-ft) 46.8 34.2 103.7 40.5 TP Load (mt) 14.0 4.5 14.7 7.3 FWMC (ppb) 242.5 107.4 115.1 145.7

FWMC = Flow-Weighted Mean Concentration. WY2002 = May 2001 to April 2002.

There was a marked increase in TP concentrati on in WY 2005 and 2006 in the untreated discharge from G-300 and G-301, as well as in the treated disc harge from STA 1W. The increase in flows at

the G300 + G301 diversion structures seen in WY 2005 and 2006 is due to decreased capacity in STA-1W due to hurricane damage which occu rred in 2004 and STA enhancement construction activities. The decreased capacity in STA-1W, c oupled with the partial capacity in the newly constructed STA-1E, resulted in the need for increas ed diversion at the G300 and G301 structures.Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

15 1.2.2.2 WBID 3265B (WCA-2A Southwest Perimeter )

WBID 3265B encompasses 11,201 acres of Everglades Water Conservation Area 2A (Figure 2). This WBID is entirely Everglades marsh or canals. During 2006 this WBID was subdivided into WBIDs 3265F and a small portion of 3265H (Figures 1 and 2, Appendix B). WBID 3265B receives surface water discharges from the S-7 structure and a portion of STA-2 (G335) via a 3,400 foot gap in the L-6 levee. Additionally, water may flow into 3265B through sheet flow from upstream areas of the unimpacted (unimpaired) WBID 3265D. ST A-2 receives inflow waters from both the S-6 basin, WBID 3252A, and STA-1W conveyed via the L- 7 canal. The S-7 structure discharges water from the S-7 basin including wate r treated by STA-3/4. Annual flow, total phosphorus loads, and flow-weighted mean TP concentrations at struct ures discharging to WBID 3265B are summarized in

Table 3 for the most recent five water years (2002-2006). The summary for S7 was divided into preand post-STA 3/4 periods to account for the phosphorus removal provided by the STA after September 3, 2004. TP concentrations at S- 7 improved after STA 3/4 began discharging.

All water discharged into WBID 3265B is to be treated by STA 2 or STA 3/4. These STAs have NPDES permits (FL0177946-001 and FL0300195, respectivel y). The STA 2 permit was issued in September of 2007. It includes the 10 ppb criteri on and a technology-based effluent limit (TBEL) applied to the discharge that varies from 22 ppb to 39 ppb, depending upon the phosphorus loading rate (grams P per square meter of STA per y ear) to the STA and the number of flow-ways in operation (Goforth et al. 2007a). The present STA 3/4 permit predates Florida’s adoption of the 10 ppb numeric TP criterion for the Everglades, and as such it does not reflect current water quality standards, nor does it contain revised discharge limits . FDEP has stated that they intend to reissue this permit to reflect the 10 ppb criterion, with appropriate discharge limits.Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

16 Table 4. Water Year 2002-2006 Summary of Flows, TP Load s, and Average TP Concentrations into EPA WBID 3265B (WCA-2 West Sector) (from SFWMD and FDEP, 2007).

Year Parameter G335*

STA 2 outflow S7 (pre 9/3/04) S7 (post 9/3/04, from STA3/4)
WY 2002 Flow (1000 ac-ft) 241 98 TP Load (mt) 4.9 5.8 FWMC (ppb) 16.5 47.8
WY 2003 Flow (1000 ac-ft) 308 143 TP Load (mt) 6.6 9.6 FWMC (ppb) 17.4 54.5
WY 2004 Flow (1000 ac-ft) 285 156 TP Load (mt) 5.0 8.6 FWMC (ppb) 14.3 44.5
WY 2005 Flow (1000 ac-ft) 371 132.9 176.8 TP Load (mt) 9.2 3.4 2.6 FWMC (ppb) 20.1 20.8 11.8
WY 2006 Flow (1000 ac-ft) 322.3 456.7 TP Load (mt) 8.2 10.8 FWMC (ppb) 20.7 19.2 *Only a portion of the water discharged from G335 immediately effects WBID 3265B; i.e., the portion of water that is conveyed to south.Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

17 

## 2 STATEMENT OF WATER QUALITY PROBLEM

Section 303(d) of the Clean Water Ac t requires states to submit to the USEPA lists of waters that are not fully meeting their applicable water quality standards. FDEP has developed such lists, commonly referred to as § 303(d) lists, since 1992. As part of that process, FDEP included portions of the Everglades and the EAA on their 1998 § 303( d) list as impaired by excess nutrients or depressed dissolved oxygen. During 2006 FDEP revis ited these determinations and found that the waters are still impaired (Appendices A and B).

About one-half of the 4000-square mile pre-drainage Everglades has been drained and converted to agricultural or urban land uses. The remaining com ponents of the historical Everglades have been impacted by hydrologic alterations and by the introduc tion of excessive levels of nutrients, which have resulted in the ecological degradation of the system. The Everglades is naturally an oligotrophic ecosystem that evolved in response to low ambient concentrations of nutrients and seasonally fluctuating water levels. Prior to the creation of canals, nitrogen and phosphorus were primarily supplied to the Everglades in low c oncentrations in surface water sheet flow. The historical system was phosphorus limited, with am bient phosphorus concentrations in unimpacted areas generally less than 10 ppb at interior marsh sites.

The introduction of excess phosphorus to the Evergl ades has resulted in ecological changes over large areas of Everglades marsh. These change s are caused by cultural eutrophication, which is an increase in the supply of nutrients available in th e marsh. The increase in nutrients has resulted in documented impacts to several trophic levels of aquatic life —including microbial, periphyton, macrophyte, invertebrate, and vertebrate commun ities—that constitute exceed ances of the FDEP’s Class III narrative nutrient criterion (Section 62-302.530, F.A.C.).

The excessive levels of phosphorus have also caused exceedances of the FDEP’s Class III SSAC for DO in the EPA. Nutrient enrichment typically produces a variety of system changes that ultimately result in a depressed oxygen regime in the water column. The Everglades is a highly phosphorus limited system, and as phosphorus levels increase, productivity increases, as does the accumulation of organic matter in the water and sediments (i .e., increased biochemical oxygen demand [BOD] and sediment oxygen demand [SOD]). This increas ed demand for oxygen results in greater oxygen consumption in both the water column and sediments.

In addition to an altered community metabolism, changes in vegetation occur in response to eutrophication. As the degree (intensity or dura tion) of eutrophication increases, the open water slough communities are invaded by cattail ( Typha ) and other emergent vegetation (Rutchey and Vilchek, 1994; McCormick et al., 1999). The lo ss of the open water slough community and the shading (reduced light penetration) resulting from the increased growth of floating and emergent vegetation reduce the photosynthetic production of oxygen in the water column. Ultimately, the phosphorus enrichment results in an imbalance in the oxygen sources and sinks by increasing the demand for oxygen and reducing photosynthetic oxygen production. Therefore, the diel DO curves for phosphorus-enriched areas are characterized by overall lower DO levels and dampened dielEverglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

18 fluctuations (Weaver, 2004). Several segments of the EPA are identified on the FDEP’s 2006 draft Verified List of Group 5 waterbodies as not m eeting the Class III designated use due to nutrient impairment (Appendices A and B). Such impairment is based on technical evaluations performed by the FDEP, as set forth in numerous FDEP technical documents. 1

2.1 Impaired Waterbody Segments

The impaired Everglades segments that have TMDL s due in 2007 are listed in Table 5 and shown in Figure 2. FDEP determinations for impairment ar e included in Appendices A and B, and are based on information reported on the 1998 303(d) list. Initial impairment determinations made by FDEP during 2006 for Group 5 waters are also shown. Phosphorus-impacted areas are based on water phosphorus and soil phosphorus. Florida’s Everglades TP criterion rule defines impacted as where soil TP exceeds 500 milligrams TP per kilogram of soil. Cattail also can be an indicator of phosphorus enrichment (Appendix C).

Table 5. FDEP impairment determinations for Everglades WBIDs.

Segments (WBIDs) Impaired for

Nutrients Impaired for DO

1998 2006 draft 1998 2006 draft
S-7 Basin (3263) Yes Not assessed Yes Yes
S-8 Basin (3260) Yes Not assessed Yes Potentially Impaired Knight’s Farm Field 1 (3252A) Yes Not assessed No Insufficient Data

ACME North Sector (3252C) Yes Not assessed No Yes

WCA-1 North Sector (3252B) Yes Yes Yes Insufficient Data

WCA-2 Southwest Perimeter (3265B) Yes Yes Yes Insufficient Data

2.2 Pollutants of Concern

Phosphorus is the limiting nutrient in the Evergl ades (McCormick et al. 1999, McCormick et al. 2002, Noe et al. 2001). Accordingly, the TMDLs pr oposed in this document target phosphorus. Nitrogen is another plant nutrient that can contribute to eutrophication. However, because the Everglades marsh is phosphorus-limited, nitrogen has not been a concern. There is no numeric water quality criterion for total nitrogen in the Ever glades. EPA is unaware of any data indicating that nitrogen causes imbalances in flora or fauna in Class III canals within the EAA.

1 Payne, Weaver, and Xue, 2006; Payne, Weaver, and X ue, 2007; Payne, Weaver, Goforth, and Piccone, 2005.Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

19 There are two EPA WBIDs and two EAA WBIDs that are also listed for DO. DO may be depressed by excess nutrients. It may also be depressed in canals due to groundwater influence. Attaining the appropriate levels of phosphorus is expected to result in the achievement of the DO SSAC for the Everglades marsh. Controlling phosphorus is expect ed to result in an im provement in DO within EAA canals to the extent that lowered DO is due to phosphorus pollution.

2.3 Source of Pollutants

The following discussion is adapted from SFWMD and FDEP (2007). The ma jor source of nutrient pollutants to the Everglades is stormwater. The EPA is a complex system of marsh areas, canals, levees, and inflow and outflow water control st ructures covering almost 2.5 million acres (Figure 10). The predominant source of inflow to the EP A is nonpoint source runoff resulting from rainfall. The inflows are regulated by water control structures from agricultural tributaries, such as the EAA, that feed the EPA from the north. The EAA Basin is the largest tributary source to the EPA.

The EAA Basin covers approximately 700,000 acres south of Lake Okeechobee in eastern Hendry

and western Palm Beach Counties. This area of highly productive agricultural land comprises rich organic peat or muck soils and is considered to be one of Florida’s most important agricultural regions. Approximately 77 percent of the EAA is devoted to agricultural production. The major crops in the EAA include sugar cane, vegetables, and sod, with secondary crops in rice and citrus.

The EPA also receives nonpoint s ource runoff from predominantly urbanized areas to the east (Figure 10). At times it also receives surface wate r inflows originating from Lake Okeechobee to the north for water supply, flood control, saltwater intrusion control, and environmental purposes.

As part of the Everglades Construction Project (ECP), which was mandated by the Everglades Forever Act, the SFWMD constructed five Stor mwater Treatment Areas (STA-1W, STA-2, STA3/4, STA-5, and STA-6). As part of its federal partnership with the State of Florida, the U.S. Army Corps of Engineers constructed a sixth STA, STA- 1E, which along with the other STAs, is operated and maintained by the SFWMD.

In conjunction with contributing basin BMPs, th ese STAs reduce phosphorus levels via naturally occurring biological processes prior to discharg ing into the Everglades. These facilities are considered point source discharges and, therefore, are regulated through NPDES permits, pursuant to 403.088 F.S. in addition to Everglades Forever Act permits which are issued pursuant to 373.4592,

F.S.

The SFWMD owns and operates 39 water control structures discharging into, within, or from the

EPA that are not included in the ECP. These st ructures, referred to as non-ECP structures, are operated and maintained for multiple purposes, including flood control, water supply, and the management of natural systems. Only 8 of the 39 water control structures discharge stormwater and other nonpoint source runoff from agricultural and urban areas into the EPA.

In conjunction with landowners, local governments, and other agencies, the SFWMD has developed water quality improvement strategies for each of th e eight non-ECP basins that discharge into theEverglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

20 EPA. The first line of phosphorus control in these basins is through the implementation of BMPs at the source. In addition, many local and regional water resource projects are under way to further reduce TP loading into the EPA, including Criti cal Restoration Projects associated with the Comprehensive Everglades Restoration Plan and the Acceler8 Program. The Acceler8 program is a Florida initiative to accelerate specific Everglades restoration projects, including new or expanded

STAs.

The timing and distribution of surface inflows fr om the tributaries to the EPA are based on a complex set of operational decisions that acc ount for natural and environmental system requirements, aquifer recharge, flood control, a nd water supply for agriculture, urban areas and natural areas. Each year, the EPA receives va riable amounts of surface water inflows based on rainfall and resulting hydrologic variability in the ups tream basins. These inflows also contribute a certain amount of TP loading to the EPA system. In some cases, surface water inflows represent a

mixture of water from several sources as the wate r passes from one area to another before finally arriving in the EPA. For example, water disc harged from Lake Okeechobee can pass through the EAA and then through an STA before arriving in the EPA.

Some of the TP loading to the EPA is from atmospheric deposition. Annual average atmospheric deposition of TP ranges from 107 to 143 metric tons (mt) as the total contribution to the WCAs. Deposition rates are highly variable and very expens ive to monitor and, as such, atmospheric inputs of TP are not routinely monitored. The range (20 to 35 milligrams per square meter per year [mg/m 2 /yr]) is based on data obtained from long-term monitoring that was evaluated by the SFWMD, as reported in Redfield (2002).

The most common water quality problems in the Evergl ades are elevated levels of nutrients and low DO. TP levels are higher than statewide median s, and most of the DO observations fall below the 5.0 mg/l Class III water quality criterion. Many of the impaired waterbodies are canals. In

constructed waterbodies it is difficult to consistently meet DO standards developed for natural water systems such as lakes and streams. In the EAA, the impaired waterbodies are canals where low DO concentrations occur naturally.Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

21 Figure 10. The Everglades Protection Area and tributary basins (from SFWMD and FDEP, 2007).Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

22 

## 3 WATER QUALITY STANDARDS

Water quality criteria established by the State of Florida are described in the Florida Administrative Code (F.A.C.), Section 62-302.530. The individual crite ria should be considered in conjunction with other provisions in water quality standards, in cluding Section 62-302.500 F.A.C. [Surface Waters: Minimum Criteria, General Criteria] that apply to all waters unless alternative or more stringent criteria are specified in F.A.C. Section 62-302.530. In addition, the designated use and water quality

of downstream waters must be maintained.

All waters of the EPA (wetland or canal) are de signated as Class III: recreation, propagation and maintenance of a healthy, well-bala nced population of fish and wildlife. In addition, the Refuge and Everglades National Park are both designated as Outstanding Florida Waters (OFWs), under Section 62-302.700, F.A.C. This non-degradation status require s that the quality of water that existed the year prior to the 1979 designation is maintained. Class IV waters are designated for agricultural water supply.

The WBIDs within the EAA include Class III can als as well as Class IV canals. FAC 62- 302.400(12)(a): All secondary and tertiary canals who lly within agricultural areas are classified as Class IV and are not individually listed as exceptions to Class III. “Secondary and tertiary canals” shall mean any wholly artificial canal or ditch whic h is behind a control structure and which is part of a water control system that is connected to the works (set forth in Section 373.086, F.S.) of a water management district created under Section 373.069 F. S., and that is permitted by such a water management district pursuant to Section 373.414, or Section 373.416, F.S. Agricultural areas shall generally include actively used solely for the production of food and fiber which are zoned for agricultural use where county zoning is in effect.

FDEP has made no determination as to which canals within the EAA are Class III waters and which

canals are Class IV waters. For purposes of this TMDL document, it is assumed that Class III canals within the EAA are those that are constructed by the U. S. Army Corps of Engineers or SFWMD that are part of the C & SF Project, and are maintained and operated by the SFWMD, or are considered Works of the District. Agricultural canal s that have been constr ucted by and are operated by private interests are assumed to be Class IV canals with a designated use of agricultural water supply.

The Everglades BMP Regulatory Program for the EAA (Rule 40E-63, F.A.C.) requires that dischargers to the SFWMD’s Works (canals) in th e EAA basins obtain a permit for those discharges. Rule 40E-63 permits approve a BMP plan and a wa ter quality monitoring plan for TP for each subbasin or farm, as applicable. Currently, there are 33 EAA basin BMP permits, including approximately 205 sub-basins and 286 privately owned water control structures discharging into the

SFWMD canals in the EAA. Most of the sub-basi ns have muck soils and highly managed drainage systems that use pumps. The areas represented by single permits vary substantially in size, from 120 to 92,000 acres. Each permit approves an on-site implementation plan for BMPs (BMP plan) in accordance with the EFA (Subparagraph 373.4592[4][f][2][c], F.S.), which states that permits issued under the Everglades Regula tory Program require BMPs for varying crops and soil types. The BMPEverglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

23 plan includes operational programs or physical e nhancements designed to reduce phosphorus levels in water discharged to the SFWMD canals. As of 1996 the EAA basin as a whole was to have achieved a 25% TP load reduction in a given wate r year when compared to a pre-BMP baseline period of 1978 to 1988. The EAA met this requirement basin-wide from WY1996 to WY2007.

All farms within the EAA are subject to this BMP rule, and all structures discharging from these farms into the SFWMD’s works (Class III canals) have permits. Monitoring of phosphorus and discharge is required at these private pumps. A ll canals and conveyances to the upstream side of these pumps are considered Class IV canals.

3.1 

### Nutrient Criteria

3.1.1 Nutrient Criteria for Class III Waters

The designated use of Class III waters is recrea tion, propagation and maintenance of a healthy, wellbalanced population of fish and wildlife. FDEP has not adopted a numeric nutrient criterion for

Class III canals within the EAA. Therefore, the Class III narrative criterion applies to these canals:

Nutrients (62-302.530(48)(a)): The discharge of nutrients shall continue to be limited as needed to prevent violations of other standards contained in this chapter. Man induced nutrient enrichment (total nitrogen and total phosphorus) shall be considered degradation in relation to the provisions of Section 62-302.300, 62-302.700, and 62-4.242, FAC.

62-302.530(48)(b) In no case sh all nutrient concentrations of a body of water be altered so as to cause an imbalance in natural populations of aquatic flora or fauna

For the Everglades Protection Area, in 2005 Flor ida established and USEPA approved a numeric phosphorus criterion that has been determined thr ough research to be protective of the natural populations of aquatic flora and fauna of the Everglades. The phosphorus criterion is a long-term geometric mean of 10 ppb, as specified in S ection 62-302.540, F.A.C. This numeric criterion applied to the entire EPA.

3.1.2 Nutrient Criteria for Class IV Waters

The designated use of Class IV canals is agricultu ral water supply. FDEP has not adopted numeric

nutrient criteria for Class IV canals within the E AA. Therefore, the following Class IV narrative criterion applies to canals within the EAA:

Nutrients (62-302.530(48) (a)): The discharge of nutrients shall continue to be limited as needed to prevent violations of other standa rds contained in this chapter. Man induced nutrient enrichment (total nitrogen and total phosphorus) shall be considered degradation in relation to the provisions of Section 62-302.300, 62-302.700, and 62-4.242, FAC.

3.2 Dissolved Oxygen Criteria

3.2.1 DO Criteria for Class IV Canals

The DO criterion that applies to Class IV canals within the EAA is as follows:Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

24 DO (62-302.530(31)): Shall not average less th an 4.0 mg/l in a 24-hour period and shall never be less than 3.0. Normal daily and seasona l fluctuations above these levels shall be

maintained.

In applying the DO criterion in this TMDL, EPA also considered the definition of natural background and the directive not to abate natura l conditions set out in Florida’s water quality

standards. See 62-302.200(15) FAC and 62-302.300(15) FAC.

3.2.2 DO Criteria for Class III Canals

The DO criterion that applies to Class III canals within the EAA and Everglades is as follows:

DO (62-302.530(31)): Shall not be less than 5.0 mg/l. Normal daily and seasonal

fluctuations above these levels shall be maintained.

The narrative nutrient criterion is also controlli ng as it relates to dissolved oxygen [62-302.530(48) (a)].

The discharge of nutrients shall continue to be limited as needed to prevent violations of other standards contained in this chapter.

3.2.3 DO Site Specific Alternative Criteria

The 1994 EFA directed FDEP and the SFWMD to evaluate existing water quality standards applicable to the EPA. As documented in the Everglades Consolidated and Interim Reports (1999– 2003), DO concentrations in the macrophyte- and periphyton-dominated marshes of the Florida Everglades routinely fall below the state Class III water quality criterion (Section 62-302.530, F.A.C.) of 5.0 milligrams of oxygen per liter (mg O 2 /L) on a daily basis and exhibit wide daily (diel) fluctuations due to the natural processes of phot osynthesis and respiration. For example, in a pristine marsh community in the Park, with bladde rwort and an extensive calcareous periphyton mat, the DO naturally fluctuated over 24 hours from 0.8 to 11.0 mg/L, and was < 5.0 mg/L for about 50% of the day (Scheidt et al.,1985).

In recognition of these naturally occurring fluctu ations that do not meet the Class III DO criterion, the FDEP established a DO Site Specific Alterna tive Criterion (SSAC) for the marsh within the EPA; this SSAC was adopted by FDEP on Janua ry 26, 2004, and approved by the USEPA on June 16, 2004 as a revision to the Florida Water Quality Standards. Because a single-value criterion does not adequately account for the wide-ranging natural diel fluctuations obser ved in the marsh, the DO SSAC provides a mechanism to account for the ma jor factors (time of day and temperature) influencing natural background DO variation in the Everglades.

FDEP identified marsh reference s ites within WCA 2A based on TP and ecological conditions. Diel data were used to define a relationship betw een DO, time of day and water temperature. A predictive sinusoidal model was developed that de fines the average DO regime at these reference

sites. The model was cross-validated with a set of reference sites from other parts of the Everglades. The curve predicted by the model was then adjust ed to account for natural temporal (seasonal andEverglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

25 annual) and spatial variability. Since the mode l defines the average condition, lower natural fluctuations would still be expected. Therefore, the model was adjusted so that the 10% lower rejection limit is used as the SSAC assessment lim it. Compliance with the SSAC is based on a comparison between the annual average of multip le DO measurements made throughout the year, and the average of the corresponding DO values specified by the model (Weaver, 2004). The achievement of the Everglades DO SSAC is assessed annually, with the results reported in the South Florida Environmental Report (SFER) (Weaver et al., 2007).

3.2.4 Natural Conditions

Florida’s water quality standards provide a definition of natural background:

“Natural Background” shall mean the condition of waters in the absence of man-induced alterations based on the best scientific information available to the Department. The establishment of natural background for an altered waterbody may be based upon a similar unaltered waterbody or on historical pre-alteration data

.

See 62-302.200(15), FAC.

Florida’s water quality standards also provide that:

Pollution which causes or contributes to new vi olations of water quality standards or to continuation of existing violations is harmful to the waters of this State and shall not be allowed. Waters having water quality below th e criteria established for them shall be protected and enhanced. However, the Depa rtment shall not strive to abate natural

conditions.

See 62-302.300(15) FAC.Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

26 

## 4 TARGET IDENTIFICATION

TMDLs identify the maximum amount of a pollutant that can be added to a waterbody without exceeding water quality standards. Additionally, a llocations in a TMDL must not result in, or contribute to, any violation of other water qua lity standards for the waterbody or water quality

standards downstream.

4.1 Basis and Rationale For Phosphorus Targets

Numeric targets for this TMDL are required to pr ovide for a level of nutrients that will ensure protection for aquatic life for Class III waters. A dditionally, the allocations of TMDLs for waters within the EAA must not impact, but protect, downstream waters of the Everglades.

4.2 Phosphorus Target Development

4.2.1 Everglades Protection Area

Florida has adopted and USEPA ha s approved a long-term geometric mean TP criterion for the EPA of 10 ppb. This 10 ppb long-term geometric mean water quality criterion applies throughout the EPA. Walker (2005) determined that the ratio of the long-term flow-weighted mean to the long-term geometric mean across all STAs for 24 water year s is 1.18, with a standard error 0.04. The criterion has been calculated to translate into an equivale nt maximum annual flow-weighted concentration of approximately 16 ppb at discharges into the Everglades (Payne et al. 2005b, Walker 2005). Payne et al. (2005b) concluded that a TP effluent limit of 15.5 ppb expressed as a maximum annual flowweighted mean is recommended for incorporation in to permits for all discharges into the EPA to assure that the discharges do not cause or cont ribute to exceedances of the phosphorus criterion in the downstream marsh receiving waters. This target can be re-evaluated in the future as more data become available. Although the annual maximum limit has not been formally adopted by FDEP as a Water Quality Based Effluent Limit (WQBEL), at the present time it represents the direct translation of the long-term numeric criterion to the discharge such that all water delivered to the EPA would

meet the numeric criterion with a level of confidence.

The 16 ppb annual maximum concentration limit is used as the basis for the TP TMDL for discharges to WBIDs within the EP A. This approach should assure that all waters delivered to the

EPA at WBIDs 3252B and 3265B will meet the TP criterion. The TMDL is based on an annual maximum concentration-based discharge limit of 16 ppb th at applies to all discha rges into the EPA. The TMDL is applied in future years by multiplying 16 ppb TP times the annual discharge and conversion factors to determine the acceptable TP load limit for that year. For example, annual discharge into the Refuge between WY 2002 and WY2006 ranged from about 225,000 acre-feet to 606,000 acre-feet (see Appendix D). Multiplying th e 16 ppb limit by each annual discharge results in an annual maximum TP load limit for these y ears ranging from 4.4 to 12.0 metric tons per year (mt/yr). Likewise, annual discharge into 3265B at S-7 between WY 2002 and WY2006 ranged from about 98,000 to 457,000 acre-feet (Appendix D). Multiplying the 16 ppb limit by each annual discharge results in an annual maximum TP load lim it for these years ranging from 1.9 to 9.0 mt/yr.Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

27 4.2.2 Everglades Agricultural Area

Targets for TP in the EAA were derived from tw o independent approaches as described below.

4.2.2.1 Approach #1: Estimate STA inflow loads res ulting in WQS in downstream waters

In order to meet the 10 ppb criterion and protect downstream waters of the EPA, STAs must discharge an annual maximum of 16 ppb. STA performance is a function of phosphorus loading rate (PLR), expressed as grams TP per acre of ST A area per year (Kadl ec 2006, Pietro et al., 2007, Goforth et al., 2007a-2007f). PLR was used as the basis for deriving the Technology Based Effluent Limits (TBELs) that are in the NPDES permits issued in September 2007 for STA 2 , STA 5 and STA 6 (Goforth et al., 2007a, 2007b, 2007c). As PL R increases, the projected STA discharge TP concentration also increases. Relationships also have been explored for TP concentration at STA inflow versus TP outflow concentration (Pietro et al., 2007). The best predictor of STA outflow TP concentration appears to be PLR. PLR and ex isting STA acreage can be used to calculate the corresponding TP inflow load to the STA that will allow attainment of the desired effluent limits (Table 7). The inflow TP load is the product of inflow concentration and flow.

Pietro et al. (2007) summarize annual STA perfor mance across all STAs for the history of the program. From 1995 to 2006 the three years with th e lowest STA outflow concentrations (1997, 19 ppb; 1998, 20 ppb and 1999, 19 ppb) had corresponding PLRs of 0.93, 0.82 and 0.75, and inflow TP concentrations of 98 ppb, 98 ppb, and 90 ppb, respectively (Table 6). Outflow TP for the other nine years ranged from 20 ppb to 44 ppb; PLR was always greater th an 1.0, ranging from 1.26 to 3.51; and inflow TP concentrations were all great er than 100 ppb, ranging from 109 ppb to 147 ppb. The years with the performance closest to the 16 ppb discharge goal all had PLRs less than 1.0 g/m 2 /yr and inflow TP less than 100 ppb. This 100 ppb concentr ation is used as the initial STA inflow target

concentration until such time that it is demonstrat ed that the STAs can attain the maximum annual flow-weighted concentration of 16 ppb discharge goa l with a higher inflow concentration. This concentration of 100 ppb is applied as the TMDL ba sis for the Class III waters within the EAA that discharge into the STAs. The basis is the require ment that the STAs discharges meet water quality

standards for downstream waters.

In addition, since Class IV agricultural waters mu st be of adequate quality to protect downstream waters, the 100 ppb TP requirement is also applied to the private pumps within the EAA WBIDs at the point that they discharge into the Class III canals. This 100 ppb requirement is not applied throughout the Class IV canals, but only at the point where they discharge into Class III canals.Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

28 Table 6. Years with the lowest annual STA outflow TP concentration across STAs from 1995 to 2006 (Pietro et al., 2007).

WY PLR g/m2/y

r TP inflow flow-weighted mean (ppb) TP outflow flow-weighted mean (ppb)

1997 0.93 98 19

1998 0.82 98 20

1999 0.75 90 19

A TMDL must be adequate to assu re that the designated use of as waterbody will be restored. FDEP

has determined that the Class III canals within th e EAA WBIDs are impaired for nutrients, and the designated use of these waters is not being met. FDEP presently uses a TP screening concentration of 220 ppb to indicate potential impairment for waterbodies. Because the 100 ppb goal for Class III

waters within the EAA is much less than the 220 ppb screening level, th e 100 ppb goal should result in attainment of the designated use for these Class III canals. If in the fu ture FDEP changes water quality standards within the EAA for canals, such as by changing the designated use or adopting a numeric TP criterion, then this draft TMDL goal can be revisited.

Review of the adopted TBELs for STA 2, ST A 5 and STA 6 (Goforth et al. 2007a, 2007b and 2007c) and the draft TBELs for STA 2, STA 1W and STA 1E (Goforth et al. 2007c, 2007d and 2007e) also indicate that a PLR of 1.0 g/m 2 /yr or lower is necessary in order for the STA outflow concentration to approach 16 ppb. Kadlec (2006) notes that in order to achieve an STA effluent of less than 20 ppb, STA PLR less than 1.0 is necessar y. For these reasons, this TMDL assumes an

STA PLR of 1.0 or less as a requirement for attaining a maximum annual flow-weighted concentration of 16 ppb at STA outflows. This TMDL can be revised in the future if STA performance demonstrates that a higher PLR can in fact sustain a maximum annual flow-weighted STA discharge of 16 ppb.

For illustration purposes, existing STA treatment acr eages are used to calculate the corresponding STA inflow TP load that would result in a PLR of 1.0 g/m 2 /yr as follows: PLR x STA acres x unit conversion factors (Table 7). It should be noted that the 18,000 acre expansion of STAs that is underway will result in higher acceptable STA TP in flow loads while simultaneously maintaining the 1.0 PLR objective.Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

29 Table 7. Annual STA inflow TP loads based on PLR of 1.0 g/m 2 /year.

STA Downstream Impaired

WBID Treatment Area

WY2006

(acres) Inflow TP Load (metric tons)

STA 1W 3252B 4181 17.0

STA 1E 3252B 4024 16.3

STA 2 3265B/F 6430 26.2

STA 3/4 3265B/F 14,253 58.0

4.2.2.2 Approach #2: Simple modeling approach

A simple modeling approach was used where dist urbed land use was changed in the four WBIDs outside of the Everglades Protection Ar ea (3260, 3263, 3252A and 3252C) to reflect natural conditions (forest and wetlands). A spreadsheet based on USEPA’s Pollutant Load (PLOAD) model (USEPA, 2001) was used to develop TP and TN targ ets. The spreadsheet was used to calculate nonpoint source loadings for nutrients as the produc t of the water quality concentration and runoff volume associated with certain land use practices. For these four WBIDs TP target concentrations

are based on undisturbed conditions. Land uses classified as urban, agriculture, pasture, commercial, industrial, extractive or barren were considered disturbed categories and were changed to wetlands. Runoff volumes were calculated using estimates of annual average rainfall and Event Mean Concentrations (EMCs) for the various la nd uses. Annual average rainfall for the EAA is about 50.2 inches. Event Mean Concentrations (E MCs) assumed for each land use type in Florida were selected from those compiled by Harper a nd Baker (2003). Model results from the four

WBIDs indicate that the TP concentration for na tural conditions was projected to be 82 ppb to 89 ppb, with an average concentration of 87 ppb (Appendix E).

This procedure is designed to estimate loading to the Class III canal. It does not contain any water quality dynamics or a link to aqua tic life use support but assumes th at aquatic life is supported under natural conditions. The utility of this tool is best used to predict background, or undisturbed, loading

to the canal which is then used to estimate natu ral resulting concentrations. The 87 ppb average TP concentration is similar to the 100 ppb STA inflow requirement. Therefore, EPA is assuming that the 100 ppb STA inflow target will also protect the designated uses of the EAA canals.

4.3 DO Target

FDEP established a DO Site Specific Alternative Cr iterion (SSAC) for the marsh within the EPA to address the naturally occurring fluctuations in DO in the marsh that do not meet the Class III DO criterion of 5.0 mg/L. Therefore, the DO target for WBIDs within the EPA is the DO SSAC. EPAEverglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

30 anticipates that attainment of the 10 ppb long-term TP criterion in those portions of the Everglades marsh not attaining the DO SSAC (WBIDs 3252B a nd 3265B) will result in those WBIDs attaining

the SSAC.

The DO target for the remainder of the Class III wate rs in the EPA and EAA is Florida’s applicable water quality standard for DO of 5 mg/L. EPA notes , however, that it is likely that many of these waters will not attain the applicable water quality standard for DO, even if the nutrient loads established in this TMDL are met. All Everglades canals are artificial conveyances that are influenced by groundwater which contains very low DO concentrations. Even canals within the Everglades with extremely low TP concentrati ons, such as the Tamiami Canal at Everglades National Park, typically have natural DO concentr ations that are less than the 5.0 mg/L Class III criterion, especially before noon. In canals that ar e not nutrient impaired, attainment of the TP criterion does not necessarily mean that the DO crite rion will be met. EPA believes that the nutrient target for this TMDL, which is based on a considera tion of natural levels of TP as well as the level of TP that can be delivered to STAs and still pr otect the downstream Everglades marshes, limits TP so that it does not exert a negative effect on DO, as required by Florida’s narrative criterion for

nutrients. See 62-302.530(48)(a), FAC. Limiting TP beyond this point is not expected to have any

additional beneficial effect on DO. A revised DO criterion (SSAC) for canals that are not impaired by nutrients should be considered to recognize that DO is naturally low in these artificial waterbodies. FDEP is in the process of investigating revised DO criteria for canals.

The DO target for the Class IV canals in the EAA is Florida’s applicable water quality standard: shall not average less than 4.0 mg/L in a 24-hour period and shall never be less than 3.0 mg/L. Similarly to the Class III canals, EPA does not exp ect the Class IV canals to attain the DO minimum of 3.0 mg/L at all times, even if the TP goal is met. For example, WBIDs 3260 and 3263 meet the 100 ppb TP goal, yet these waters are listed as impaired for DO. As set above regarding the Class III canals, EPA believes this TMDL limits TP so th at it does not exert a ne gative effect on DO, as required by Florida’s narrative criterion for nutrients . A revised criterion should be considered by FDEP that would recognize that DO is naturally low in these artificial waterbodies.Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

31 

## 5 WATER QUALITY RESULTS

Current phosphorus conditions within the EAA are shown in Table 8. Summary data for each WBID are presented in two ways. The annual mean TP concentration for each farm discharge was summarized by WBID (see Appendix D and references). The overall arithmetic mean for the WBID was then calculated. In addition, the TP concentra tions were also weighted by the acreage of each farm (area-weighted) in order to more accurately reflect overall loading conditions for the WBID. The arithmetic mean of annual discharge data Fo r WY 2007 discharge TP concentrations by farm field post-BMP ranged from 23.5 ppb to 629 ppb (Van Horn and Pescatore 2007). During WY 2002

to WY2006 TP concentrations in the EAA WBIDs th at are the subject of this TMDL document, weighted by farm acreage, averaged 63 ppb for th e S-8 basin (WBID 3260), 94 ppb for the S-7 basin (WBID 3263) and 168 ppb for Knight’s Farm Field 1 (WBID 3252A) (Appendix D).

Figure 11. WY2006 flow-weighted mean TP con centrations in the EAA (Van Horn and Pescatore 2007).Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

32 For WY2002 to WY2006 the average TP concentration discharged into the Refuge (from STA-1W, STA-1E, G-300 and G-301) at WBID 3252B was 87 ppb, with an average annual load of 39 metric tons. For WY2002 to WY2006 the average TP concentration discharged into WBID 3265B at S-7 was 36 ppb, with an average annual load of 8 metric tons. It should be noted that once STA 3/4 came on line in 2004, TP concentrations at S- 7 decreased (see Table 4). During WY2002-WY2004, TP load data for EAA farms were not reported.

Table 8. WY2002 to WY 2006 TP concentration and load for EAA and EPA WBIDs.

WBID WY2002-WY2006

TP concentration (ppb) Area-weighted WY2002-WY2006

TP concentration (ppb) WY2002-WY2006

TP load (metric tons/year)

3263

S-7 93.8 ppb

Post-BMP 89.9 ppb

Post-BMP 45.0*

3260

S-8 62.7 ppb

Post-BMP 91.9 ppb

Post-BMP 35.2*

3252A Knights Farm Field 1 168.0 ppb

Post-BMP 164.8 ppb

Post-BMP 52.9*

3252C ACME North

Sector - 115.2 ppb 3.5

3265B

WCA 2B - 36 ppb into 8.2 into

3252B Refuge North Sector - 87 ppb into 39.4 into

EAA farm data are from Siev ers et al. 2003, McGinnes et al. 2004, McGinnes et al. 2005, Pescatore and Vega 2006, and Van Horn et al. 2007. ACME data are from Goforth et al. 2003, Piccone et al. 2004, Payne et al. 2005a, 2006, 2007.

* loads were only reported for WY2005-WY2006.Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

33 

## 6 SOURCE ASSESSMENT

An important part of the TMDL analysis is the identification of source categories and the amount of pollutant loading contributed by these sources. Sour ces are broadly classified as either point or nonpoint sources. Phosphorus originating from at mospheric deposition is allocated to background loads. Several of the WBIDs are also impaired for DO. The sources contributing to nutrient impairment can also contribute to the low DO. Low DO concentrations in canals may also be attributed to groundwater influence due to channelization.

6.1 Background Loads

A certain amount of TP loading to the EPA is from atmospheric deposition. Annual average atmospheric deposition of TP ranges from 107 to 143 metr ic tons (mt) as the total contribution to the WCAs. Deposition rates are highly variable a nd very expensive to monitor and, as such, atmospheric inputs of TP are not routinely monito red. The range (20 to 35 milligrams per square meter per year [mg/m 2 /yr]) is based on data obtained from long-term monitoring that was evaluated by the SFWMD, as reported in Redfield (2002).

6.2 Permitted Point Sources

A point source is defined as a discernable, confin ed, and discrete conveyance from which pollutants are or may be discharged to surface waters. Poin t source discharges of industrial wastewater and treated sanitary wastewater must be authorized by National Pollutant Discharge Elimination System (NPDES) permits. NPDES permitted facilities disc harging treated stormwater are typically considered primary sources of nutrients. Wast e Load Allocations (WLAs) are assigned to all NPDES permits discharging to surface waters.

6.2.1 Traditional Point Sources

Traditional point sources are defined as continuous release municipal or industrial wastewater NPDES permitted facilities. There are no traditiona l NPDES facilities discharging to surface waters in the impaired WBIDs.

6.2.2 Stormwater Treatment Areas (STAs)

Stormwater Treatment Areas (STAs) are large parcel s of wetlands planted with specific species that act as filters to remove nutrients. The STAs remove phosphorus from agricultural stormwater runoff, facilitating restoration of downstream wate rbodies. The four STAs discharging into EPA WBIDs 3252B and 3265B are subject to NPDES pe rmit requirements (Table 9). For STA-2, interim period 1 applies when three STA flow-way s are in operation, and interim period 2 applies when four flow-ways are in operation (Goforth et al., 2007a)Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

34 Table 9. Permitted Facilities Discharging into impaired EPA WBIDs.

Name of Facility Facility ID WBID Annual maximum TP limit (ppb)

STA-1E FL0304549 3238E 68 *

STA-1W FL0177962 3238C 68 *

STA-2 FL0177946 3254A

Interim Period 1 30.4 -38.9

Interim Period 2 22.4 – 28.8

STA-3/4 FL0300195 3262B 68 *

* based on the initial 1994 goal of 50 ppb, not the new criterion of 10 ppb adopted in 2005. Applies only when the STA is in the post-stabilization operations phase.

6.2.3 Municipal Separate Storm Sewer System Permittees

Like other nonpoint sources of pollution, urban stormw ater discharges are associated with land use and human activities, and are driven by rainfall a nd runoff processes leading to the intermittent discharge of pollutants in response to storms . The 1987 amendments to the Clean Water Act designated certain stormwater discharges from urbanized areas as point sources requiring NPDES stormwater permits. The three major components of the NPDES stormwater regulations are:

• Municipal Separate Storm Sewer Systems (or MS4) permits that are issued to entities that own and operate master stormwater systems, primarily local governments. Permittees are required to implement comprehensive stormwater manageme nt programs designed to reduce the discharge of pollutants from the MS4 to the maximum extent practicable.

• Stormwater Associated with Industrial Activities, which is regulated primarily by a multisector general permit that covers various types of industrial manufacturing facilities and requires the implementation of stormwater pollution prevention plans.

• Construction activity generic permits for projects that disturb one or more acres of land and which require the implementation of stormwat er pollution prevention plans to provide for erosion and sediment control during construc tion and the treatment and management of stormwater to minimize pollution and flooding.

In October 2000, USEPA authorized FDEP to impl ement the NPDES stormwater program in all areas of Florida except Indian Tribal lands. FDEP ’s authority to administer the NPDES program is set forth in Section 403.0885, Florida Statutes. The Stormwater Rule was established as a technology-based program that relies on the implemen tation of BMPs that are designed to achieve a specific level of treatment (i.e., performance standards) as set forth in Chapter 62-40, F.A.C.

The Stormwater Rule requires the state’s wate r management districts (WMDs) to establish stormwater pollutant load reduction goals (PLRGs ) and adopt them as part of a Surface WaterEverglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

35 Management Plan, other watershed plan, or rule. Stormwater PLRGs are a major component of the load allocation part of a TMDL. To date, stormw ater PLRGs have been established for Tampa Bay, Lake Thonotosassa, the Winter Haven Chain of La kes, the Everglades, Lake Okeechobee, and Lake Apopka.

The NPDES stormwater program was implemented in phases, with Phase I MS4 areas including municipalities having a population above 100,000. Because the master drainage systems of most local governments in Florida are interconnected, EPA implemented Phase 1 of the MS4 permitting program on a countywide basis, which brings in all cities, Chapter 298 urban water control districts, and the Florida DOT throughout the fifteen counties meeting the population crite ria. Phase II of the NPDES Program was expanded in 2003 and requires stormwater permits to construction sites between one and five acres, and to local governments with as few as 10,000 people.

Although MS4 discharges are technically referre d to as “point sources” for the purpose of regulation, they are still diffuse sources of polluti on that cannot be easily collected and treated by a central treatment facility. Most MS4 permits issued in Florida include a re-opener clause allowing permit revisions for implementing TMDLs once they are formally adopted by rule.

MS4 entities covering the drainage basins of the impaired WBIDs are shown in Table 10. The only MS4 permit is in WBID 3252C and is for the Village of Wellington. There ar e no urban areas in the WBIDs 3260, 3263 or 3252A of sufficient population to be covered by an MS4 permit. All future areas with populations meeting the MS4 requirement s will be required to achieve the allocations presented in the TMDL.

Table 10. MS4 Permitees in the Drainage Basins of Impaired WBIDs.

County Permit/Co-Permit Name Permit ID Number MS4 Type

Palm Beach Village of Wellington FLS000018 Phase II

6.3 Nonpoint Sources

Unlike traditional point source effluent loads, nonpoi nt source loads are diffuse sources that cannot be identified as entering a waterbody through a di screte conveyance at a single location. These sources generally, but not always, involve accumula tion of nutrients on land surfaces that wash off as a result of storm events. Nonpoint sources of phosphorus loadings in the Everglades watershed include agriculture, wildlife, and stormwater runoff. All non-point runoff that is delivered to the EPA passes through a water control structure, a nd is easily monitored for discharge volume and nutrient concentrations. A summary of anthropoge nic nonpoint sources in th e Everglades watershed is presented below.Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

36 6.3.1 Agriculture

Agricultural activities, which are the principle land uses in the impaired WBIDs, discharge large quantities of nutrients to the waterbodies through stormwater runoff.

Sugarcane has been grown commercially in the EAA since the 1920s and is one of the most economically important crops in the state. Sugarcane planting and harvesting operations are conducted during the fall and winter. During th e summer wet months area farms store water by flooding vacant sugarcane fields or by growing paddy rice. Sugarcane is planted in rotation with rice, sod, spring and fall corn, and other assorted ve getables. To maximize the efficient use of plant nutrients in the soil, a rotation from higher to lower fertility requiring crops is normally practiced. Like any other plant, sugarcane requires nutrients for optimum growth. In the EAA, nutrients are provided from rainfall, irrigation water, organic so ils, and fertilizer. Research studies based on yield responses have been used to establish guidelines cu rrently used for fertilizer rates. Studies have shown that sugarcane biomass removes more phosphorus from the soil than the amount applied as

fertilizer.Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

37 

## 7 TMDL ALLOCATION

TMDLs identify the maximum amount of nutrients that can be added to a waterbody without exceeding water quality standards so as to prot ect the listed waterbodies and the downstream Everglades Protection Area.

The TMDL process quantifies the amount of a pollu tant that can be assimilated in a waterbody, identifies the sources of the pollutant, and recomme nds regulatory or other actions to be taken to attain the applicable water quality standards based on the relationship between pollution sources and in-stream water quality conditions. The objective of a TMDL is to allocate loads among all of the known pollutant sources throughout a watershed so that appropriate control measures can be implemented and water quality standards achieved.

7.1 Allocation

A TMDL can be expressed as the sum of all point source loads (Wasteload Allocations or WLA), nonpoint source loads (Load Allocations or LA), and an appropriate margin of safety (MOS), which accounts for uncertainty concerning the relationship between effluent limita tions and water quality:

TMDL = Σ WLAs + Σ LAs + MOS

Federal regulations provide that TMDLs can be expressed in terms of mass per time (e.g. pounds per day), toxicity, or other appropriate measure ( 40 C.F.R.§ 130.2(i)). TMDLs for the EPA WBIDs are expressed as annual maximum flow-weighted TP concentration. Corresponding annual and daily loads are also presented for information purposes. However, attainment of the TMDL is based on the TP concentrations of 16 ppb (annual maximum) for waters discharged into the EPA and 100 ppb (annual average) within the EAA for waters discha rged into Class III canal s or the STAs. Annual flows in the Everglades fluctuate due to variation in annual rainfall. Flow will also vary over time as

a series of new restoration activities are cons tructed and become operational (STA expansion, conveyance canals, water control structures, etc.) Strategies implemented in the watershed to achieve the TP TMDLs should also improve DO cond itions to the extent that excess phosphorus is lowering DO.

The TMDL components are provided in Table 11 and are expressed as annual concentrations. The TMDL for EPA WBIDs is applied by multiplying 16 ppb times the annual flow and appropriate conversion factors. The target TP concentrations represent annua l values and the TMDLs should be implemented to achieve the annual concentrations. An implicit Margin of Safety (MOS) is assumed

in all of these TMDLs as described in Section 7.4. The percent reduction required to achieve water quality standards is calculated using the following equation:

% Reduction = (existing load – TMDL) / (existing load) * 100

7.2 Load Allocation (LA)

A LA is assigned to nonpoint sources in the waters hed. For the EPA WBIDs, it is assumed that allEverglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

38 inflow is treated by STAs. Therefore, there are no nonpoint sources in the WBID and the entire

TMDL is allocated to the Wasteload Allocati on. Any water that does not pass through an STA before being discharged into these EPA WBIDs is still subject to the 16 ppb flow-weighted annual maximum requirement of this TMDL.

For the EAA WBIDs, there are no traditional NPDE S facilities, MS4s or permitted STAs within these WBIDs. The entire TMDL is assigned to th e Load Allocation. The TMDL was determined by reducing the WY2002 to WY 2006 TP loads and concentrations to meet the 100 ppb inflow target.

7.3 Wasteload Allocation (WLA)

For the EPA WBIDs it is assumed that all inflow is treated by STAs. Therefore the entire load into these WBIDs is assigned to the wasteload alloca tion. In future years the TMDL is applied by multiplying 16 ppb times the annual flow and appropria te conversion factors. The WLA is to be reflected in the NPDES permits for the appropriate STAs. All future point sources discharging to surface waters impacting the impaired WBIDs w ill be required to meet the 16 ppb requirement

established in these TMDLs.

7.4 Margin of Safety

An implicit margin of safety for waterbody prot ection was provided in the TMDL analysis. The maximum annual flow-weighted TP concentration of 16 ppb is equivalent to the 10 ppb long-term geometric mean criterion for the Everglades mars h. This was based in part on STA performance data. This approach assumes that the same discha rge limit can be applied to all STAs and inflows. Application of the TP criterion at the discharg e point into the EPA assumes that there is no assimilative capacity in the receiving canals and ma rsh (i.e., any TP above the criterion would result in a phosphorus change that would be determined to be an imbalance). For the EAA WBIDs, the 100 ppb target was derived as what is necessary at STA inflows in order to protect downstream waters of the EFA. This 100 ppb target (applied to Class III canals within the EAA and Class IV discharges into Class III canals) is less than th e 220 ppb screening level presently used by FDEP for TP impairment. This results in a margin of safety for protection of the desi gnated use of these Class

III waters within the EAA.Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

39 Table 11. TMDL allocation for Total Phosphorus

Notes:

1. TMDL expressed as an averag e annual load is calculated by multiplying 16 ppb times the annual

flow and conversion factors. To express the TMDL as a daily lo ad, the annual load is divided by 365 days per year.

2. Based on STA inflow need of 100 ppb to meet STA effluent of 16 ppb annual maximum.

3. Allocation given to Class IV canals necessary to protect the downstream Class III waters and should be implemented and monitored at the point of entry into Class III waters.

4. Based on WY2002-WY2006 data

5. Assumes all flow into this WBID is treated by STAs with NPDES permits. WBID Water

Class TMDL 1,2,3
(ppb) WLA (ppb) LA (ppb) 2,3 MOS Percent

Reduction 4

Everglades Agricultural Area or ACME Improvement District

Class III 100 0 100 Implicit 0%

3263 (S-7)

Class IV 100 0 100 (at inflow to Class III canal) Implicit 0%

Class III 100 0 100 Implicit 0%

3260 (S-8)

Class IV 100 0 100 (at inflow to Class III canal) Implicit 0%

Class III 100 0 100 Implicit 41% 3252A (Knight’s

Farm Field 1) Class IV 100 0 100 (at inflow to Class III canal) Implicit 41%

3252C (ACME North Sector) Class III 100 0 100 Implicit 13%

Everglades Protection Area

3265B (3265F, 3265H; WCA2A Southwest Sector) Class III 16 (see note 5) 16 Implicit 56%

3252B (Refuge North Sector) Class III 16 (see note 5) 16 Implicit 82%Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

40 7.5 

### Seasonal Variability

Seasonal variability was addressed in the selection of the nutrient target concentrations by considering data collected during all seasons. The data used for deriving the TP targets for the EPA and EAA include many years and seasons, various rainfall conditions, and several years of STA data. The data used to determine an acceptable TP loading rate and inflow for the STAs likewise capture over 10 years that include wet and dry conditions, various rainfall conditions, and drought

and hurricanes.



## 8 TMDL IMPLEMENTATION

The Clean Water Act [Section 303(d)(2)] directs that a TMDL established by the Environmental Protection Agency be implemented by a State pursu ant to subsection 303(e). A State can establish its own procedures for implementation. Federal re gulations provide direction on implementation of TMDLs in the permitting process. At a minimum, NPDES permits must include a permit limit consistent with the assumptions of an approved wasteload allocation. Presently, STA 2 has an issued NPDES with such an initial TBEL permit lim it. STA 1W, STA 1E, and STA3/4 do not have such permits.

Implementation of these TMDLs is the responsibility of Florida. Attainment of the TMDL may necessitate a variety of measures depending upon the basin and the existing quality of water. Florida has laid out such measures in their long-term plan for achieving water quality goals for tributary

basins to the EPA. STA PLR is a function of ST A size, inflow volume and inflow TP concentration.

STA inflow concentration and flow can be a ffected by many factors including land use practices, agricultural BMP effectiveness and delivery of wa ter from Lake Okeechobee. Decisions about how to attain these TMDL targets are left to the expertise of FDEP, SFWMD and private interests.Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

41 

## 9 REFERENCES

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Florida Administrative Code (F.A.C.) 62-302.530. Criteria for Surface Water Quality

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Goforth, Gary, Tracey Piccone, Stuart Van Hor n, Doug Pescatore and Cheol Mo. 2003. Chapter 8A: achieving long-term water quality goals. 2003 Everglades Consolidated Report. South Florida Water Management District. West Palm Beach, Florida.

Goforth, Gary, Nenad Iricanin, Steve Hill, Sh i Kui Xue, Tracey Piccone, Frank Nearhoof and Ken Weaver. 2007a. Technical support document for the STA-2 TBEL. May 17, 2007.

Goforth, Gary, Nenad Iricanin, Steve Hill, Sh i Kui Xue, Tracey Piccone, Frank Nearhoof and Ken Weaver. 2007b. Technical support document for the STA-5 TBEL. June 3, 2007.

Goforth, Gary, Nenad Iricanin, Steve Hill, Sh i Kui Xue, Tracey Piccone, Frank Nearhoof and Ken Weaver. 2007c. Technical support document for the STA-6 TBEL. June 3, 2007.

Goforth, Gary, Nenad Iricanin, Steve Hill, Sh i Kui Xue, Tracey Piccone, Frank Nearhoof and Ken Weaver. 2007d. Technical support document for the STA-1W TBEL. July 5, 2007.

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2007.

Harper, H. H. and D. M. Baker. 2003. Evalua tion of alternative stormwater regulations for southwest Florida. Environmental research and design, Inc.

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McCormick, Paul C., Susan Newman, ShiLi Mia o, Ramesh Reddy, Dale Gawlik, Carl Fitz, Tom Fontaine and Darlene Marley. 1999. Ecological Needs of the Everglades. Chapter 3 in Everglades Consolidated Report. January 1, 1999. South Florida Water Management

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42 Fontaine. 2002. Effects of anthropogenic phosphorus inputs on the Everglades. pages 83-126 in J. W. Porter and K. G. Porter, eds. The Everglades, Florida Bay, and coral reefs of the Florida Keys: An ecosystem sourcebook. CRC Press LLC, Boca Raton, FL.

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Noe, G. B., D. L. Childers, and R. D. Jones. 2001. Phosphorus biogeochemistry and the impact of phosphorus enrichment: Why is the Everglades so unique? Ecosystems 4:603-624.

Payne, Grover, Kenneth Weaver, Gary Goforth a nd Tracey Piccone. 2005a. Chapter 2C: status of phosphorus and nitrogen in the Everglad es Protection Area. 2005 South Florida Environmental Report. South Florida Water Management District. West Palm Beach,

Florida.

Payne, Garry, Kenneth Weaver and Frank Nearhoof . 2005b. Draft. Derivation of the water quality based effluent limit (WQBEL) for phosphorus discharges to the Everglades Protection Area. Florida Department of Envi ronmental Protection. Tallahassee, Florida.

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Pescatore, Doug and Jose Vega. 2006. Appendix 3-1a: Water year 2005 permit-level data. 2006 South Florida Environmental Report. S outh Florida Water Management District. West Palm Beach, Florida.

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Redfield, G. 2002. Atmospheric deposition of phosphorus: concepts, constraints and publishedEverglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

43 deposition rates for ecosystem management. SFWMD (EMA) Report 403. South Florida Water Management District. West Palm Beach, Florida.

Rutchey, K., and L. Vilchek. 1994. Development of an Everglades map using SPOT image and global positioning system. Photogrammetric Engineering and Remote Sensing. 60:767-775.

Scheidt, Daniel J., David R. Walker, Ramona G. Rice and Mark D. Flora. 1985. Diel dissolved oxygen levels under experimental nutrient loading conditions in Shark Slough, Everglades National Park, Florida. Florida Scientist 48: supplement 1:36.

Scheidt, D. J. and P. I. Kalla. 2007. Everglades ecosystem assessment: water management, water quality, eutrophication, mercury contamination, soils and habitat. Monitoring for adaptive management: a R-EMAP status report. EPA 904-R-07-001. United States Environmental Protection Agency. Atlanta, Georgia.

Sievers, Pamela, Doug Pescatore, Jose Vega and Nancy Wilson. 2003. Appendix 3-1: Water year 2002 permit-level data. 2003 South Florida Environmental Report. South Florida Water Management District. West Palm Beach, Florida.

South Florida Water Management District and Fl orida Department of Environmental Protection. 2007. Reasonable assurances documentation for the Everglades Protection Area. Final. August 2007.

University of Florida. 2001. Florida water Resources. University of Florida Extension Institute of Food and Agricultural Sciences WQ101. Gainesville, Florida. April 2001.

USEPA, 1991. Guidance for Water-Quality Based Decisions: the TMDL Process. United States Environmental Protection Agency, Office of Water, Washington, DC EPA-440/4- 91-001. April 1991. Washington, D. C.

USEPA, 2000. Nutrient Criteria Technical Guidance Manual, Rivers and Streams. United States Environmental Protection Agency, O ffice of Water, Washington, DC EPA-822-B00-002. Washington, D. C.

USEPA, 2001. BASINS PLOAD Version 3.0 users manual. United States Environmental Protection Agency, Office of Water, Washington, DC.

Walker, William W. Jr. 2005. Estimation of water quality based effluent limits for measuring compliance with the Everglades phosphorus criterion. Draft for discussion purposes. 2005. 14 pages

Weaver, K. 2004. Everglades Marsh Dissolved Oxygen Site Specific Alternative Criterion Technical Support Document. Tallahassee, Florida: Florida Department of Environmental

Protection.

Weaver, K., and G. Payne. 2004. Chapter 2A: Status of Water Quality in the Everglades Protection Area. G. Redfield (Ed.). In: 2004 Everglades Consolidated Report. West Palm Beach, Florida: South Florida Water Management District.Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

44 Weaver, K., G. Payne, and S. Xue. 2007. Chapter 3A: Status of Water Quality in the Everglades Protection Area. G. Redfield (Ed.). In: 2007 South Florida Environmental Report – Volume I. West Palm Beach, Florida: South Florida Water Management District.

Van Horn, Stuart and Doug Pescatore. 2007. A ppendix 4-2: Water year 2006 permit-level data. 2007 South Florida Environmental Report. S outh Florida Water Management District. West Palm Beach, Florida.Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

45 

## APPENDIX A: Summary of Everglades WBIDs. Draft TMDLs due September 30, 2007 are shaded in yellow.Everglades – Nutrient Total Maximum Daily Load US EPA Region 4 September 200746WBIDsWBID NAME1998 303(d) WBIDWaterbody TypeEVERGLADESLONG-TERMPLAN BASINNAMENutrientTMDL on1998(d) listCD YEARNUTRIENTTMDL DUEDesignatedUseOutstandingFloridaWater?WITHIN EVERGLADES PROTECTION AREALOXAHATCHEE NATIONAL WILDLIFE REFUGE3252BWCA1 north sector AUnchangedEverglades MarshNAYES2007Class IIIYES3252DWCA1 west sectorUnchangedEverglades MarshNANONEClass IIIYES3252WCA1 center sectorUnchangedEverglades MarshNAYES2012Class IIIYES3252GWCA1 east sector AUnchangedEverglades MarshNANONONEClass IIIYES3252EWCA1 south sectorUnchangedEverglades MarshNAYES2012Class IIIYES3252HLOXA west sectorEverglades MarshNANONONEWATER CONSERVATION AREA 23265GWCA2A center sector3265A, 3265E, 3265D,3265Everglades MarshNAYES2012Class IIIYES3265HWCA2A center sector3265B, 3265E, 3265D,3265Everglades MarshNAYES2007Class IIIYES3265FWCA2A center sector3265B, 3265DEverglades MarshNAYES2007, 2012Class IIIYES3272WCA2BUnchangedEverglades MarshNAYES2012Class IIIYESWATER CONSERVATION AREA 33268HWCA3A south sector3268, 3268A, 3268B,3278AEverglades MarshNAYES2012Class IIIYES3268IWCA3A south sector3268, 3268B, 3268CEverglades MarshNAYES2012Class IIIYES3268GWCA3A south sector3268, 3268B, 3268C,3268DEverglades MarshNAYES2012Class IIIYES3268FWCA3A south sector3278AEverglades MarshNAYES2012Class IIIYES3268JWCA3A south sector3278, 3278EEverglades MarshNAYES2012Class IIIYESEVERGLADES NATIONAL PARK3289JENP L-67 culvert US 41UnchangedEverglades MarshNANONONEClass IIIYES3289ENP Shark SloughUnchangedEverglades MarshNAYES2008Class IIIYES3289KENP Taylor SloughUnchangedEverglades MarshNANONONEClass IIIYES3303C-111UnchangedEverglades MarshNANONONEClass IIIYES3261BTamiami CanalUnchangedBig CypressSwampNANONONEClass IIIYESEverglades – Nutrient Total Maximum Daily Load US EPA Region 4 September 200747WBIDsWBID NAME1998 303(d) WBIDWaterbody TypeEVERGLADESLONG-TERMPLAN BASINNAMENutrientTMDL on1998(d) listCD YEARNUTRIENTTMDL DUEDesignatedUseOutstandingFloridaWater?WBIDS DISCHARGING INTO THE EVERGLADES PROTECTION AREAFROM EAA (NORTH)3233Canal, FarmsL-8NOTMDL doneunder LOtribsClass IIINO3238EM canalCanal, FarmsS-5ANONONEClass III, IVNO3238West Palm Beach CanalCanal, FarmsS-5ANONONEClass III, IVNO3244East BeachCanal, FarmsNANONONEClass III, IVNO3247715 FarmsCanal, FarmsNANONONEClass IIINO3249East ShoreCanal, FarmsNANONONEClass IIINO3248AHillsboro CanalCanal, FarmsS-7/S-2YES2012 2006Class III, IVNO3252AKnights Farm field 1Canal, FarmsS-5AYES2007Class III, IVNO3254Hillsboro CanalCanal, FarmsS-6YES2012Class III, IVNO3253South BayCanal, FarmsNANONONEClass IIINO3248North New river canalCanal, FarmsS-2/S-7NONONEClass III, IVNO3263S-7Canal, FarmsS-7YES2007Class III, IVNO3263AHoleylandEverglades Marshnot in EPAS-7YES2012Class IIIYES3260BHoleylandEverglades Marshnot in EPAS-8NONONEClass IIIYES3250S-236Canal, FarmsNAYES2012Class IIINO3251S-3Canal, FarmsS-3/S-8NONONEClass III, IVNO3260S-8Canal, FarmsS-8YES2007Class III, IVNOFROM WEST3255Canal, FarmsC-139NONONEClass IIINO3260AL3Canal, FarmsS-8YES2012Class IIINOEverglades – Nutrient Total Maximum Daily Load US EPA Region 4 September 200748WBIDsWBID NAME1998 303(d) WBIDWaterbody TypeEVERGLADESLONG-TERMPLAN BASINNAMENutrientTMDL on1998(d) listCD YEARNUTRIENTTMDL DUEDesignatedUseOutstandingFloridaWater?3266L28 InterceptorCanal, Farms,SeminoleReservation,MiccosukeeReservationL-28YES2012FloridaClass III,MiccosukeeClassSeminoleClassNO3267Canal, FarmsFeeder BasinNONONEClass IIINO3269L-28 gapBig CypressSwampNANONONEClass IIIYES3261BBig CypressSwampNANONONEClass IIIYESFROM EAST3252CCanal, FarmsYES20073252FCanal, FarmsACME BYES2012Class IIINO3264UrbanNSIDNONONEClass IIINO3275UrbanNNRCNONONEClass IIINO3277CUrbanNNRCYES2011Class IIINO3277UrbanNNRCYES2011Class IIINO3277BUrbanNNRCNONONEClass IIINO3280UrbanNNRCNONONEClass IIINO3279UrbanC-11WYES2011Class IIINO3301UrbanNONONEClass IIINO3303AUrbanNONONEClass IIINOEverglades – Nutrient Total Maximum Daily Load US EPA Region 4 September 200749WBIDsJurisdictionalGovernmentCWA StateStructuresdischarginginto WBID?Structurepermit?Numeric TPdischargelimit inpermitEPA 4-parttest station?SoilTP >500mg/kgAnnualSW TP >15 ppbannualCattailpresentEMAP UFImpairedFloridaGroup 5?ImpairedUSEPA?WBIDS WITHIN EVERGLADES PROTECTION AREALOXAHATCHEE NATIONAL WILDLIFE REFUGE3252BDOI - USFWSFloridaG-300, G-301,STA1E,STA1WNPDES,EFA;G300,G301 NoNoImpacted 3YESYESSome5 YESYES3252DDOI - USFWSFloridaNoneNANAImpacted 1YESYESDominant5 YESYES3252DOI - USFWSFloridaNoneNANAUnimpacted 8NoNoNo2NO3252GDOI - USFWSFloridaACMENon-ECPNoImpacted 2;Unimpacted 2-YESSome5 YESYES3252EDOI - USFWSFloridaNoneNANAUnimpacted 4SomeNoSome2NO3252HDOI - USFWSFloridaNoneNANANANANANANANAWATER CONSERVATION AREA 23265GFloridaFloridaSTA2, S-10sNPDES,EFANoImpacted 3YESYESDominant5 YESYES3265HFloridaFloridaNoneNANAUnimpacted 5SomeNoSome2NO3265FFloridaFloridaS-7, STA2NPDES,EFANoNoSomeNo dataSome5 YESYES3272FloridaFloridaS-144, S-145,S-146Non-ECPNoNoNoNo dataSome2NOWATER CONSERVATION AREA 33268HFloridaFloridaS-11s, S-7,STA3/4NPDES,EFANoUnimpacted 3;Impacted 1;gap in northYESYES2YES- splitWBID3268IFloridaFloridaS-8NPDES,EFANoImpacted 2YESYESYES5 YESYES3268GFloridaFloridaNoneNANAUnimpacted 4SomeNoNo2NO3268FFloridaFloridaS-9Non-ECPNoNoNoNo dataSome2NO3268JFloridaFloridaS-9Non-ECPNoUnimpacted 3;gap in northSomeNo dataSome2YES- splitWBIDEverglades – Nutrient Total Maximum Daily Load US EPA Region 4 September 200750WBIDsJurisdictionalGovernmentCWA StateStructuresdischarginginto WBID?Structurepermit?Numeric TPdischargelimit inpermitEPA 4-parttest station?SoilTP >500mg/kgAnnualSW TP >15 ppbannualCattailpresentEMAPUFImpairedFloridaGroup 5?ImpairedUSEPA?EVERGLADES NATIONAL PARK3289JDOI - NPS,Miccosukee TribeFlorida;MiccosukeeTribeS-12A-D, S333, S-355ABNoNoNASomeNo marshdata; S!2sNoSome2NO3289DOI - NPSFloridaS-332sNon-ECPNoNASomeNoNo2NO3289KDOI - NPSFloridaS-332sNANoNoNo2NO3303DOI - NPSFloridaS-18C, S-197Non-ECPNoNASomeNoNoGroup IVYESNO3261BDOI - NPSFloridaNoneNANANANANA?WBIDS DISCHARGING INTO THEEVERGLADES PROTECTION AREAFROM EAA (NORTH)3233NAFloridaNANANANA3238ENAFloridaNANANANA3238NAFloridaNANANANA3244NAFloridaNANANANA3247NAFloridaNANANANA3249NAFloridaNANANANA3248ANAFloridaNANANANA3252ANAFloridaNANANANA3254NAFloridaNANANANA3253NAFloridaNANANANA3248NAFloridaNANANANA3263NAFloridaNANANANA3263AFloridaFloridaNANANANA3260BFloridaFloridaNANANANA3250NAFloridaNANANANA3251NAFloridaNANANANA3260NAFloridaNANANANAFROM WEST3255NANANANANA3260ANANANANANAEverglades – Nutrient Total Maximum Daily Load US EPA Region 4 September 200751WBIDsJurisdictionalGovernmentCWA StateStructuresdischarginginto WBID?Structurepermit?Numeric TPdischargelimit inpermitEPA 4-parttest station?SoilTP >500mg/kgAnnualSW TP >15 ppbannualCattailpresentEMAPUFImpairedFloridaGroup 5?ImpairedUSEPA?3266Miccosukee Tribe,Seminole TribeFlorida,MiccosukeeTribe,SeminoleTribeNANANANA3267NASeminoleTribe,FloridaNANANANA3269DOI - NPSFlorida,MiccosukeeTribe,SeminoleTribeNANANANA3261BDOI - NPSFlorida,MiccosukeeTribeNANANANAFROM EAST3252CFloridaNANANANA3252FNAFloridaNANANANA3264NAFloridaNANANANA3275NAFloridaNANANANA3277CNAFloridaNANANANA3277NAFloridaNANANANA3277BNAFloridaNANANANA3280NAFloridaNANANANA3279NAFloridaNANANANA3301NAFloridaNon-ECPNONANANANA3303ANAFloridaNon-ECPNONANANANAEverglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

52 

## APPENDIX B: Draft 2006 impairment determinations by FDEP

FDEP 2006 draft Group 5 verified list impairment determinations for phosphorus. Red indicates that the waterbody is impaired and a TMDL is required, green indicate that the waterbody is attaining all designated uses.Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

53 FDEP 2006 draft Group 5 verified list impairment determinations for dissolved oxygen. Red indicates that the waterbody is impaired and TMDL is required, green indicate that the waterbody is attaining all designated uses. Grey indicates insufficient data to make a determination, yellow indicates waterbody is potentially impaired.Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

54 

## APPENDIX C: Indicators of phosphorus impairment in the EPA.

Cattail presence throughout the EPA 2004-2005. Data ar e from the University of Florida, SFWMD and USEPA R-EMAP (Scheidt and Kalla 2007).Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

55 Soil TP concentration throughout the EPA 2004-2005. Da ta are from the University of Florida, SFWMD and USEPA R-EMAP (Scheidt and Kalla 2007).Everglades – Nutrient Total Maximum Daily Load US EPA Region 4 September 200756APPENDIX D: Calculation of current water quality conditionsDischarges into the Refuge at WBID 3252B. Acre-feet are times 1000. Data are from Table 3.WYG300+G301untreatedG251STA1W outflowG310STA1W outflowS362STA1E outflowTotalFlowTPloadFWMC FlowTPloadFWMC FlowTPloadFWMC FlowTPloadFWMC FlowTPloadFWMC*TP loadat 16 ppb(ac-ft) (mt) (ppb) (ac-ft) (mt) (ppb) (ac-ft) (mt) (ppb) (ac-ft) (mt) (ppb) (ac-ft) (mt) (ppb) (mt)2002 11 1.6 118 7 0.2 19.8 261 12 37.3 279.0 13.8 40.0 5.52003 10 2.5 202 97 5.5 44.1 499 33.454.2 606.0 41.4 55.0 12.02004 17 3.1 148 55 3 44.2 243 14.1 46.9 315.0 20.2 51.9 6.22005 69 27 317 63 7.8 100.4 320 38.7 97.815.9 7.6 387.3 467.9 81.1 140.3 9.22006 47 14 242 34 4.5 107.4 104 14.7 115.140.54 7.3 145.7 225.5 40.5 145.9 4.4Average378.7 39.4 86.6 7.5FWMC = flow-weighted mean concentration.* FWMC is weighted by structure flow.Discharges at S-7 into WBID 3265B. Data are from Table 4.WY S-7 to 9/3/04 S-7 after 9/3/04 TotalFlow TP load FWMC Flow TP load FWMC Flow TP load Average TPTP Load at16 ppb(1000 ac-ft) (mt) (ppb) (1000 ac-ft) (mt) (ppb) (1000 ac-ft) (mt) (ppb) (mt)2002 98 5.8 47.8 98.0 5.8 47.8 1.92003 143 9.6 54.5 143.0 9.6 54.5 2.82004 156 8.6 44.5 156.0 8.6 44.5 3.12005 132.89 3.4 20.8 176.8 2.6 11.8 309.7 6 15.7 6.12006 456.7 10.8 19.2 456.7 10.8 19.2 9.0Average 232.7 8.16 36.34 4.6Everglades – Nutrient Total Maximum Daily Load US EPA Region 4 September 200757Discharges from ACME basin B (WBID 3252C).Water Year TP Load (mt) Flow-weighted TP (ppb) Flow (1000 ac-ft) Data sourceACME 1 ACME 2 Total ACME 1 ACME 2 Average ACME 1 ACME 2 Total2002 1.7 3.3 5 89 152 120.5 16 18 34 Goforth et al., 20032003 0.9 1.4 2.3 80 117 98.5 9 9 18 Piccone et al., 20042004 0.9 1.2 2.1 72 101 86.5 10 10 20 Payne et al., 20052005 2 2.9 4.9 133 212 172.5 12.3 11.2 23.5 Payne et al., 20062006 1.4 1.8 3.2 80 116 98 14.2 12.8 27 Payne et al., 2007Average 3.52 115.2 24.5FWMC = flow-weighted mean concentration.TP conditions in EAA WBIDs3260 (S-8) 3263 (S-7) 3252A (Knight's Farm Field 1)WaterYearTP load FWMC AW FWMC* TP load FWMCAWFWMC*TP load FWMCAWFWMC*Data Source(mt) (ppb) (ppb) (mt) (ppb) (ppb) (mt) (ppb) (ppb)2002 105.7 63.3 82.8 74.3 120.7 131.7 Sievers et al, 20032003 78.5 55.1 79 77.5 160.4 150.3 McGinnes et al, 20042004 61.1 48.7 72.7 72.8 135 129.8 McGinnes et al, 20052005 23.6 88.6 59.9 35.7 92 98.7 56.2 203.3 200.9 Pescatore and Vega, 20062006 46.7 125.8 86.3 54.2 123.2 145.7 49.5 204.8 227.5 Van Horn and Pescatore, 2007Average 35.2 91.9 62.7 45.0 89.9 93.8 52.9 164.8 168.0* AW FWMC = Area weighted flow-weighted mean concentration.For example, TP concentration at a discharge from a 20,000 acre farm isweighted ten times the TP concentration for a 2000 acre farmEverglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

58 

## APPENDIX E: PLOAD model, EMC values and results

Average annual non-point source loads of nutrients were estimated using a spreadsheet based on EPA’s Simple Method formula from the BASINS PLOAD model (EPA, 2001):

LP = Σ u (P * PJ* RVu * Cu* Au * 2.72 / 12)

Where: LP = Pollutant load, lbs

P = Precipitation, inches/year

PJ = Ratio of storms producing runoff (default = 0.9)

RVu= Runoff Coefficient for land use type u, inches of runoff/inches of rain

RVu=0.05 + (0.009 * Iu); Iu = percent imperviousness

Cu = Event Mean Concentration for land use type u, milligrams/liter

Au = Area of land use type u, acres

This method calculates nonpoint source loadings fo r nutrients as the product of the water quality

concentration and runoff water volume associated with certain land use practices. An annual average rainfall of 50 inches was used. The de fault ratio of 0.9 for storms producing runoff was

used. Land use data entered in to the spreadsheet were based on the SFWMD land use/cover features categorized according to the Florida Land Use and Cover Classification System (FLUCCS). Event Mean Concentrations (EMCs) for each land use type in Florida were compiled by Harper and Baker (2003), and are provided below. 1999 land us e was used for WBIDs 3260 and 3263, and 2004 land

use was used for 3252A and 3252C.Everglades – Nutrient Total Maximum Daily Load US EP A Region 4 September 2007

59 PLOAD EMC values

FLUCCS

ID Land Use Total P (mg/L)

1000 Urban Open 0.09

1100 Low Density Residential 0.09

1200 Medium Density Residential 0.09

1300 High Density Residential 0.09

2000 Agriculture 0.09

3000 Rangeland 0.09

4000 Forest/Rural Open 0.046

5000 Open Water 0.07

6000 Water/ Wetlands 0.09

7000 Barren land/Transition 0.09

8000 Communication and Transportation 0.09

PLOAD TMDL condition results

WBID TP (mg/l) TP (lb/yr)

3260 0.089 5467

3263 0.088 3915

3252A 0.087 1468

3252C 0.082 127