F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

F K R A D

South-Central Keys Area Reasonable 

Assurance Documentation 

FKRAD Program 

December 2008 

Prepared for 

FLORIDA DEPARTMENT OF ENVIRONMENTAL PROTECTION 

Watershed Management Bureau 

Tallahassee, Florida 

Prepared by 

Camp, Dresser & McKee, Inc. 

1715 N. Westshore Boulevard 

Tampa, Florida 33607

URS Corporation Southern 

7650 Courtney Campbell Causeway 

Tampa, Florida 33607
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Prelim TOC.doc

ACKNOWLEDGEMENTS 

The South-Central Keys Area Reasonable Assurance Document was developed under 

the direction of Mr. Fred Calder and Mr. Pat Fricano of the Florida Department of 

Environmental Protection (FDEP) with the assistance of the following stakeholder’s 

representatives: 

Mr. Edward Barham, Environmental Director, Naval Air Station Key West; 

Ms. Elizabeth Wood, P.E., Wastewater Section Chief, Monroe County; and 

Mr. Jaime Barrera, FDOT District IV. 

The authors gratefully acknowledge the comments review comments of the 

Stakeholders technical representatives and Mr. Gus Rios, Manager of FDEP’s Marathon 

Service Office. The document was developed a collaborative effort led by Mr. Scott 

McClelland of CDM Inc. and Mr. Stephen Lienhart of URS Corporation. 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Prelim TOC.doc ii 

South-Central Keys Area Stakeholders Agreements 

As a measure of reasonable assurance and support of this document, the stakeholders in 

the South-Central Keys Area (US Navy, Monroe County, and FDOT) have provided signed 

documents confirming that the management activities identified in this document indeed 

reflect the commitments of the stakeholders. The signed documents are contained in 

Exhibit 1. 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Prelim TOC.doc iii 

Table of Contents 

Executive Summary 

1. BACKGROUND 

1.1 Purpose of the Document 1-1 

1.2 Reasonable Assurance Process 1-2 

1.3 Uniqueness of the Florida Keys 1-3 

1.4 Geographic Extent of the South-Central Keys Area 1-4 

1.5 Stakeholder Group Process 1-5 

1.5.1 Stakeholder Group Membership 1-5 

1.5.2 Technical Working Group 1-5 

2. DESCRIPTION OF THE IMPAIRED WATERS 

2.1 Understanding of Impairment in the Florida Keys 2-1 

2.1.1 Problem Definition 2-1 

2.1.2 Historical Water Quality Information 2-1 

2.1.3 Impacts of External/Far Field Sources 2-3 

2.2 Impaired Waters 2-5 

3. DESCRIPTION OF THE WATER QUALITY TARGETS 

3.1 Water Quality Targets 3-1 

3.1.1 Florida Water Quality Standards 3-1 

3.1.2 Water Quality Targets for Aquatic Resources 3-1 

3.1.3 Water Quality Targets Based on Insignificant Anthropogenic 

 Increases 3-4 

3.1.4 Water Quality Targets Based on OFW Designation 3-5 

3.1.5 Water Quality Standards for Hawaii as Comparison 3-5 

3.2 Restoration of the Designated Uses of the Impaired Waters 3-7 

4. DESCRIPTION OF THE PROPOSED MANAGEMENT 

ACTIONS TO BE UNDERTAKEN 

4.1 Names of the Responsible Participating Entities 4-1 

4.2 Proposed Management Activities Designed to 

 Restore Water Quality 4-1 

4.3 Scope of Management Activities 4-2 

4.4 Estimated Pollutant Load Reduction from the Implementation 

 of Individual Management Actions 4-3 

4.4.1 Baseline Nutrient Loading 4-4 

4.4.2 Nutrient Removals by Proposed Management Activities 4-5 

4.4.3 Estimated Nutrient Load Reductions 4-6 

4.4.4 Assessment of Water Quality Benefits 4-8 

4.5 Other Benefits Anticipated from Implementation of 

 Individual Management Actions 4-16 

 4.5.1 Modeled Canals 4-16 

 4.5.2 Additional Benefits 4-24 

4.6 Agreements Committing Participants to the Management Actions 4-24 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Prelim TOC.doc iv 

4.7 Assessment of Future Growth and New Sources 4-25 

4.7.1 Future Growth Potential 4-25 

4.7.2 New Pollutant Sources 4-26 

4.8 Confirmed Sources of Funding 4-28 

4.9 Implementation Schedule 4-28 

4.10 Enforcement Programs and Local Ordinances for Non-Voluntary 

 Strategies 4-29 

4.10.1 Local Focus Regulatory Program Elements 4-29 

4.10.2 State Agency Enforcement Responsibilities 4-29 

5. STATE SCHEDULE TO ACHIEVE WATER QUALITY 

TARGETS 

5.1 Achieving Water Quality Targets 5-1 

5.2 Schedule to Achieve Targets 5-1 

6. PROCEDURES FOR MONITORING AND REPORTING 

RESULTS 

6.1 Description of Procedures for Monitoring and Reporting Results 6-1 

6.1.1 Monitoring Networks 6-1 

6.1.2 Procedures for Monitoring and Reporting Results 6-2 

6.2 Quality Assurance/Quality Control Elements 6-4 

6.3 Procedures for Entering all Appropriate Data into FL-STORET 6-5 

6.4 Responsible Monitoring and Reporting Entity 6-5 

6.5 Frequency and Reporting Format for Reporting Monitoring Results 6-6 

6.6 Frequency and Reporting Format for Implementation of Proposed 

 Management Activities 6-6 

6.7 Methods for Evaluating Progress Towards Goals 6-6 

7. PROPOSED CORRECTIVE ACTIONS 

7.1 Corrective Actions for Non-Improvement of Water Quality 7-1 

7.2 Corrective Actions for Schedule Non-Attainment of 

 Management Actions 7-1 

7.3 FDEP Notification Process for Corrective Action Implementation 7-3 

ACRONYMS AND ABBREVIATIONS 

EXHIBITS 

1. Stakeholder Agreements 

2. Stakeholder Contact Information 

3. Wastewater Management Practices 

4. Stormwater Management Practices 

5. Estimated Nutrient Load Reductions 

6. Assessment of Water Quality Benefits 

7. Confirmed Sources of Funding 

TECHNICAL INFORMATION DOCUMENT (This is a separate 

document containing referenced detail reports and information) 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Prelim TOC.doc v 

List of Tables 

Table 

1-1 FKRAD List of Stakeholders and Interested Parties ....................................... 1-7 

2-1 Issues Impacting Living Resources and Water Quality 

 In the Florida Keys .......................................................................................... 2-4 

3-1 Summary of Hawaiian Nutrient Standards (Chapter 11-54, HAR) .................. 3-6 

3-2 1985 FDEP OFW Water Quality Data ............................................................. 3-6 

3-3 1999 Baseline Nutrient Concentrations ........................................................... 3-6 

3-4 2020 Simulated Nutrient Condition with Implemented Management Actions .. 3-6 

4-1 General Management Actions ......................................................................... 4-2 

4-2 South-Central Keys Area Management Actions .............................................. 4-3 

4-3 Estimated Nutrient Loadings in South-Central Keys Area ............................... 4-4 

4-4 Baseline Annual Nutrient Loadings ................................................................. 4-5 

4-5 Summary of Estimated Nutrient Load Reductions For Proposed and 

 Implemented Management Practices .............................................................. 4-7 

4-6 Simulated Concentrations in the South-Central Keys Area Halo Zone ........... 4-9 

4-7 Modeled Canals and Model Zones ................................................................ 4-17 

4-8 Total Nitrogen Concentrations and Differences in Canal 50 ......................... 4-21 

4-9 Total Phosphorus Concentrations and Differences in Canal 50 .................... 4-22 

4-10 Modeled Canals and Model Zones ................................................................ 4-24 

4-11 Aggregate Funding Commitment for the South-Central Keys Area .............. 4-28 

6-1 Monitoring Network Reporting Frequencies .................................................... 6-6 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Prelim TOC.doc vi 

List of Figures 

Figure 

1-1 Florida Keys .................................................................................................... 1-3 

1-2 South-Central Keys Area ................................................................................. 1-4 

4-1 Simulated Nutrient Concentrations: South-Central Keys (Model 2N) ............ 4-10 

4-2 Simulated Nutrient Concentrations: South-Central Keys (Model 2S) .. .........4-11 

4-3 Simulated Nutrient Concentrations: South-Central Keys (Model 3N) ............ 4-12 

4-4 Simulated Nutrient Concentrations: South-Central Keys (Model 3S) ............ 4-13 

4-5 Simulated Nutrient Concentrations: South-Central Keys (Model 4N) ............ 4-14 

4-6 Simulated Nutrient Concentrations: South-Central Keys (Model 4S) ............ 4-15 

4-7 Model Canal Locations .................................................................................. 4-17 

4-8 Example Canal Model ................................................................................... 4-18 

4-9 Modeled Canals (Upper Keys) ...................................................................... 4-19 

4-10 Modeled Canals (Mid/Lower Keys) ............................................................... 4-19 

4-11 Configuration of Canal 50 .............................................................................. 4-20 

4-12 Total Nitrogen Concentrations in Canal 50 ................................................... 4-21 

4-13 Total Phosphorous Concentrations in Canal 50 ............................................ 4-22 

6-1 FKNMS Monitoring Stations Located in the South-Central Keys Area ............ 6-1 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Prelim TOC.doc vii 

Technical Information Document (Separate Volume) 

A. Governing Regulations 

B. Water Quality 

C. Living Resources 

D. Models and Simulations 

E. Public Involvement Program 

F. References/Bibliography 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Executive Summary.doc Page ES-1 

EXECUTIVE SUMMARY

In accordance with Section 62-303.600 FAC, this document provides reasonable assurance 

that stakeholders in the South-Central Keys Area have provided or will implement sufficient 

control mechanisms to return the area’s nearshore waters to the water quality targets. The 

South-Central Keys Area is generally described as the island of Boca Chica. The 

stakeholders include the US Navy, Monroe County, and Florida Department of 

Transportation (FDOT). 

To provide reasonable assurance, the following elements are provided: 

 Description of the Impaired Water 

 Description of the Water Quality and Aquatic Ecological Goals 

 Description of the Proposed Management Actions to Be Undertaken 

 Description of Procedures for Monitoring and Reporting Results 

 Description of Proposed Corrective Actions 

The Florida Keys is a chain of islands approximately 220 miles long, extending from the end 

of the Florida peninsula curving southwest toward the Dry Tortugas. Consisting of 822 

islands, of which about 30 are inhabited, the Florida Keys are traversed by U.S. Highway 1 

(a.k.a., US 1 or Overseas Highway) with 19 miles of bridges. The Keys are entirely within 

Monroe County and includes the municipalities of Islamorada, Key Colony Beach, Layton 

Marathon and Key West. Key West represents about 30 percent (24,000 people) of the 

population of Monroe County, which, according to the 2000 Census, is about 79,600 people. 

In general, Florida watersheds are characterized by a large land mass that concentrates 

and directs runoff to a relatively small waterbody. Thus, runoff is discharged to receiving 

waters wherein pollutants are concentrated. Soils allow infiltration and percolation slowing 

down nutrient runoff and soils facilitate the treatment of nutrients due the availability of land 

for conventional stormwater best management practices (BMPs). Also, the BMPs can be 

monitored using a relatively small number of sampling points. Similarly, with the large 

watersheds, wastewater can be controlled using septic tanks and large regional treatment 

facilities. Septic discharges through a drainfield can be absorbed into the soils and regional 

treatment discharges can be via reuse, storage, land application, deep well injection and in 

some cases, surface water discharge to receiving waters. As a result of all these factors, a 

conventional approach to pollutant controls is warranted and usually followed. 

The Florida Keys, in contrast, is a 220 miles-long string of small narrow linear islands 

surrounded by a very large receiving waterbody. As a result, local runoff is not focused and 

pollutants are dispersed in the Gulf of Mexico and Straits of Florida. Soils are such that 

infiltration and percolation are relatively enhanced, moving infiltrated runoff and its pollutants 

to nearshore waters quickly, yielding little or no nutrient entrapment or treatment in the soils 

matrix. The limited size of the land area limits the ability to place land intensive stormwater 

BMPs (such as detention or retention ponds). Also unique to the Florida Keys is the degree 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Executive Summary.doc Page ES-2 

to which external farfield pollutants circulating in marine waters impact local waters. For 

wastewater, due to the soils, high water table and tides, septic tanks have limited treatment 

capability and “regional” systems are historically limited to small package plants. Finally, 

pollutant sources outside of the control of the local governments provide the dominant 

influence on the receiving waters of the area. In this case, unconventional approaches to 

pollutant controls are required. 

Additionally, because they represents a unique terrestrial and aquatic ecosystem, Florida 

Keys have been the subject of significant regional, State and Federal scrutiny and 

regulatory oversight with most aspects of growth and development reviewed at all levels of 

government. The extent to this scrutiny will be discussed in other sections of this report 

since it is this oversight is an important element of reasonable assurance that pollution 

control activities have been, are and will be accomplished in the Florida Keys. 

Impaired Waters: Halo zone waters surrounding the South-Central Keys Area are up 

to 500 meters offshore and nearshore waters up to 12,100 meters 

offshore; these waters are Class III (Recreation, Propagation and 

Maintenance of a Healthy, Well Balanced Population of Fish and 

Wildlife) and Outstanding Florida Waters (OFW). Waters are 

impaired based on 1998 303(d) List. WBIDs include 6014C, 

6013A, 6013B, 6013C, 6013D, 6012A, 6012B, 6012C, 6012D, and 

6018, which are the Halo Zone WBIDs surrounding the islands of 

Boca Chica Key, Saddlebunch Key, Sugarloaf Key, Cudjoe Key, 

Summerland Key, Ramrod Key, Big Torch Key, Big Pine Key, Long 

Beach, No Name Key and Bahia Honda Key. 

Pollutants: Nutrients (in particular, nitrogen and phosphorus) 

Suspected Sources: Halo Zone and nearshore waters are dominated by farfield sources 

such as the natural and regulated discharges from the Everglades, 

regulated discharges from Lake Okeechobee through the Peace 

River, Caloosahatchee River, Mississippi River, etc. Anthropogenic 

sources from the South-Central Keys Area are superimposed on 

this condition. Local sources include wastewater and stormwater 

originating in the U.S. Navy Facilities in Boca Chica, 

unincorporated areas of Monroe County, and the Florida 

Department of Transportation District Six. 

Applicable Standard: Chapter 62-302.530(47) (b) – “in no case shall nutrient 

concentrations of a water body be altered so as to cause an 

imbalance of natural populations of flora and fauna.” No 

scientifically supported nutrient thresholds have been defined for 

aquatic resources in the area. 

Water Quality Target: Since the farfield sources dominate the nutrient concentrations in 

nearshore waters, the target is defined to be an insignificant 

concentration at 500 meters increase above natural background; 

insignificant means less than 10 μg/l for Total Nitrogen and 2 μg/l 

for Total Phosphorus and background means the Halo Zone 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Executive Summary.doc Page ES-3 

condition in the absence of anthropogenic loads. Another target is 

that the nearshore ambient nutrient concentrations at 500 meters 

average less than the ambient concentrations measured for the 

OFW designation. 

Management Actions: The list of completed and proposed management actions are 

provided in Table ES-1. Included are wastewater projects, 

stormwater programs and regulatory requirements. 

Load Reductions: The management actions provide the following nutrient load 

reductions: 

Water Quality Result: The predicted nearshore nutrient concentrations as a result of the 

committed management actions are provided below (within 

nearshore modeled segment 500 meters from shore): 

Nutrient Anthropogenic 

Loading 

(lb/year) 

Loading After 

Mgmt Actions 

(lb/year) 

% Loading 

Reduction 

Total Nitrogen 200,668 125,785 37% 

Total Phosphorus 46,628 24,778 47% 

Nutrient 

Model 

Natural 

Conditions 

Concentration 

(μg/l) 

1999 Baseline 

Concentration 

@ 500 meters 

(μg /l) 

Concentration 

After 

Management 

Actions @ 500 

meters (μg /l) 

Water 

Quality 

Target 

(μg /l) 

Total Nitrogen 

2N 195 206 203 205 

2S 125 141 137 135 

3N 205 207 206 215 

3S 128 133 130 138 

4N 211 214 212 221 

4S 131 132 131 141 

Total 

Phosphorus 

2N 10 13 12 12 

2S 6 10 8 8 

3N 10 11 11 12 

3S 6 7 6 8 

4N 10 10 10 12 

4S 5 6 5 7 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Executive Summary.doc Page ES-4 

Schedule: Water quality targets (insignificant increase above farfield 

concentrations) are expected to be achieved by 2020, when all 

committed wastewater and stormwater management activities are 

completed. 

Monitoring of WQ: Monitoring will be completed via a number of ongoing ambient 

water quality and biological assessment stations throughout the 

Florida Keys; monitoring will be implemented by FDEP, SFWMD, 

and the Florida Keys National Marine Sanctuary (FKNMS); results 

are report to the FKNMS Sanctuary Advisory Council with studies 

by the Florida Marine Research Institute (FMRI) and the Florida 

International University (FIU) via the Water Quality Protection 

Program (WQPP). Monitoring will be reported to the FKNMS 

Steering Committee. 

Monitoring Progress Monitoring for success will include identification of physical 

connections to the central wastewater system; number of onsite 

systems (OSTDSs) eliminated; total nutrients in wastewater 

effluent discharged to deep well; number of stormwater systems 

installed; and decrease in nearshore nutrient concentrations in 

comparison to background. Management activities will be reported 

by stakeholders to the FKNMS Steering Committee. 

Corrective Actions None are recommended at this time. However, provisions have 

been identified for corrective actions that may be required for nonattainment of management actions. 

In Summary: 

The management actions proposed in the South-Central Keys Area have, to a significant 

degree, already been implemented and are in operation. 

 Collectively, the implemented and proposed wastewater management actions will 

virtually eliminate the baseline wastewater nutrient loads that were identified for the 

area and significantly reduce the nutrient loads in the remainder (unincorporated 

county portions) of the South-Central Keys Area. 

 Similarly, the implemented and proposed stormwater management actions 

represent a significant effort for removing the baseline anthropogenic stormwater 

nutrient load that was identified for the South-Central Keys Area. 

 Finally, state, regional and local regulatory controls of growth provide limits on 

increases to pollutant loading due to uncontrolled development. 

The Stakeholders are confident that this plan provides reasonable assurance that water 

quality criteria will be met in the watersheds in the South-Central Keys Area because this 

plan specifically removes or significantly reduces the known anthropogenic sources of the 

nutrient loads to result in concentrations increases above background such that the 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Executive Summary.doc Page ES-5 

increases are below the practical quantification limits for nitrogen and phosphorus as 

defined by FDEP. 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Executive Summary.doc Page ES-6 

Table ES-1 

Summary of Estimated Nutrient Load Reductions for 

Proposed and Implemented Management Practices 

WBID Management Action 

Estimated Total 

Nitrogen Load 

Reduction 

(lbs/year) 

Estimated Total 

Phosphorous 

Load Reduction 

(lbs/year) 

Actual or 

Anticipated 

Operational Date 

IMPLEMENTED MANAGEMENT PRACTICES 

6013A-N 

Construction of the Bay Point central sanitary sewer 

system to serve 66 EDUs on with an AWT (5-5-3-1) 

treatment facility and nominal 90-foot effluent 

disposal well [Monroe County/FKAA] 

408 120 2007 

6013A-S 

Construction of the Bay Point central sanitary sewer 

system to serve 346 EDUs on with an AWT (5-5-3-

1) treatment facility and nominal 90-foot effluent 

disposal well [Monroe County/FKAA] 

2,147 632 2007 

PROPOSED FUTURE MANAGEMENT PRACTICES 

6013B-N 

Construction of the Middle Lower Keys central 

sanitary sewer system to serve 66 EDUs on with an 

AWT (5-5-3-1) treatment facility and nominal 90-foot 

effluent disposal well [Monroe County/FKAA] 

538 103 June 2009 

6013C-N 

Construction of the Middle Lower Keys central 

sanitary sewer system to serve 565 EDUs on with 

an AWT (5-5-3-1) treatment facility and nominal 90-

foot effluent disposal well [Monroe County/FKAA] 

4,580 1,116 June 2009 

6013C-S 

Construction of the Middle Lower Keys central 

sanitary sewer system to serve 2,860 EDUs on with 

an AWT (5-5-3-1) treatment facility and nominal 90-

foot effluent disposal well [Monroe County/FKAA] 

19,521 5,665 June 2009 

6013D-N 

Construction of the Middle Lower Keys central 

sanitary sewer system to serve 9 EDUs on with an 

AWT (5-5-3-1) treatment facility and nominal 90-foot 

effluent disposal well [Monroe County/FKAA] 

70 21 June 2009 

6014C-N 

Construction of the South Lower Keys central 

sanitary sewer system to serve 936 EDUs on with 

an AWT (5-5-3-1) treatment facility and nominal 90-

foot effluent disposal well [Monroe County/FKAA] 

7,605 2,124 June 2009 

6014C-S 

Construction of the South Lower Keys central 

sanitary sewer system to serve 686 EDUs on with 

an AWT (5-5-3-1) treatment facility and nominal 90-

foot effluent disposal well [Monroe County/FKAA] 

4,027 1,557 June 2009 

6014C-N 

Upgrading of the existing Boca Chica Airfield 

Secondary WWTP to AWT (5-5-3-1) treatment 

facility [U. S. Navy] 

4,714 1,387 No Later Than 

June 30, 2010 

6014C-S 

Upgrading of the existing Boca Chica Airfield 

Secondary WWTP to AWT (5-5-3-1) treatment 

facility [U. S. Navy] 

4,113 1,209 No Later Than 

June 30, 2010 

6012A-N 

Construction of the North Lower Keys central 

sanitary sewer system to serve 2,815 EDUs on with 

an AWT (5-5-3-1) treatment facility and nominal 90-

foot effluent disposal well [Monroe County/FKAA] 

19,640 5,737 December 2010 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Executive Summary.doc Page ES-7 

WBID Management Action 

Estimated Total 

Nitrogen Load 

Reduction 

(lbs/year) 

Estimated Total 

Phosphorous 

Load Reduction 

(lbs/year) 

Actual or 

Anticipated 

Operational Date 

6012A-S 

Construction of the North Lower Keys central 

sanitary sewer system to serve 813 EDUs on with 

an AWT (5-5-3-1) treatment facility and nominal 90-

foot effluent disposal well [Monroe County/FKAA] 

5,876 1,724 December 2010 

6012C-N 

Construction of the North Lower Keys central 

sanitary sewer system to serve 24 EDUs on with an 

AWT (5-5-3-1) treatment facility and nominal 90-foot 

effluent disposal well [Monroe County/FKAA] 

164 48 December 2010 

6012D-S 

Construction of the North Lower Keys central 

sanitary sewer system to serve 43 EDUs on with an 

AWT (5-5-3-1) treatment facility and nominal 90-foot 

effluent disposal well [Monroe County/FKAA] 

291 84 December 2010 

6012E-N 

Construction of the North Lower Keys central 

sanitary sewer system to serve 94 EDUs on with an 

AWT (5-5-3-1) treatment facility and nominal 90-foot 

effluent disposal well [Monroe County/FKAA] 

1,003 286 December 2010 

SOUTHCENTRAL 

KEYS AREA 

TOTAL NUTRIENT REDUCTIONS 74,697 21,813 

  
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 1.doc Page 1-1 

Section 1.0 

BACKGROUND

1.1 PURPOSE OF THE DOCUMENT 

The Impaired Waters Rule (IWR), Chapter 62-303, Florida Administrative Code 

(Identification of Impaired Surface Waters), establishes a formal mechanism for identifying 

surface waters in Florida that are impaired (do not meet applicable water quality standards) 

by pollutants. Most waters that are verified as being impaired by a pollutant will be listed on 

the state’s 303(d) list pursuant to the Florida Watershed Restoration Act (FWRA) and 

Section 303(d) of the Clean Water Act. Once listed, Total Maximum Daily Loads (TMDLs) 

will be developed for the pollutants causing the impairment of the listed waters. However, 

as required by the FWRA, the Department will evaluate whether existing or proposed 

pollution control mechanisms will effectively address the impairment before placing a water 

body on the state’s verified list. If the Department can document there is reasonable 

assurance that the impairment will be effectively addressed by the control measure(s), then 

the water will not be listed on the final verified list. 

The rule text addressing the evaluation of proposed pollution control mechanisms is as 

follows: 

62-303.600 Evaluation of Pollution Control Mechanisms 

(1) Upon determining that a water body is impaired, the Department shall 

evaluate whether existing or proposed technology-based effluent limitations 

and other pollution control programs under local, state, or federal authority 

are sufficient to result in the attainment of applicable water quality standards. 

(2) If, as a result of the factors set forth in (1), the water segment is expected 

to attain water quality standards in the future and is expected to make 

reasonable progress towards attainment of water quality standards by the 

time the next 303(d) list is scheduled to be submitted to EPA, the segment 

shall not be listed on the verified list. The Department shall document the 

basis for its decision, noting any proposed pollution control mechanisms and 

expected improvements in water quality that provide reasonable assurance 

that the water segment will attain applicable water quality standards. 

It is ultimately the Department’s responsibility to assure adequate documentation in the 

administrative record whenever the Department decides to not list an impaired water 

segment for a given pollutant. This documentation will be very important because verified 

lists will be adopted by Order of the Secretary and third parties will be provided an 

opportunity to challenge, via an administrative hearing, all listing decisions. However, the 

Department expects local stakeholders (including state and local government) will prepare 

the necessary documentation to demonstrate reasonable assurance that their proposed 

control mechanisms will restore a given water body. The Department will provide guidance 

to stakeholders on what information is needed and how it should be submitted. 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 1.doc Page 1-2 

The purpose of this document is to provide reasonable assurance that stakeholders in 

the South-Central Keys Area have provided or will provide sufficient control mechanisms 

in place to return the area’s near shore water quality to the targets set for total nitrogen 

and total phosphorus. For the purpose of this document, the stakeholders include the 

US Navy, Monroe County, and Florida Department of Transportation (FDOT). 

1.2 REASONABLE ASSURANCE PROCESS 

To provide reasonable assurance that existing or proposed pollution control mechanisms 

will restore designated uses, the following information should be evaluated and documented 

for the Administrative Record: 

(a) A Description of the Impaired Water - name of the water listed on the verified list, 

the location of the water body and watershed, the watershed/8-digit cataloging unit 

code, the NHD identifier (when they become available), the type (lake, stream, or 

estuary) of water, the water use classification, the designated use not being 

attained, the length (miles) or area (acres) of impaired water, the pollutant(s) of 

concern (those identified as causing or contributing to the impairment), and the 

suspected or documented source(s) of the pollutant(s) of concern. 

(b) A Description of the Water Quality or Aquatic Ecological Goals - a description 

of the water quality-based targets or aquatic ecological goals (both interim and final) 

that have been established for the pollutant(s) of concern, the averaging period for 

any numeric water quality goals, a discussion of how these goals will result in the 

restoration of the water body’s impaired designated uses, a schedule indicating 

when interim and final targets are expected to be met, and a description of 

procedures (with thresholds) to determine whether additional (back-up) corrective 

actions are needed. 

(c) A Description of the Proposed Management Actions to be Undertaken – names 

of the responsible participating entities (government, private, others), a summary 

and list of existing or proposed management activities designed to restore water 

quality, the geographic scope of any proposed management activities, 

documentation of the estimated pollutant load reduction and other benefits 

anticipated from implementation of individual management actions, copies of written 

agreements committing participants to the management actions, a discussion on 

how future growth and new sources will be addressed, confirmed sources of 

funding, an implementation schedule (including interim milestones and the date by 

which designated uses will be restored), and any enforcement programs or local 

ordinances, if the management strategy is not voluntary. 

(d) A Description of Procedures for Monitoring and Reporting Results – a 

description of the water quality monitoring program to be implemented (including 

station locations, parameters sampled, and sampling frequencies) to demonstrate 

reasonable progress; quality assurance/quality control elements that demonstrate 

the monitoring will comply with Chapter 62-160, F.A.C.; procedures for entering all 

appropriate data into STORET; the responsible monitoring and reporting entity; the 

frequency and format for reporting results; the frequency and format for reporting on 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 1.doc Page 1-3 

the implementation of all proposed management activities; and methods for 

evaluating progress towards goals. 

(e) A Description of Proposed Corrective Actions – a description of proposed 

corrective actions [and any supporting document(s)] that will be undertaken if water 

quality does not improve after implementation of the management actions or if 

management actions are not completed on schedule, and a process for notifying the 

Department that these corrective actions are being implemented. 

Note: The above information regarding reasonable assurance is based on a draft 

memorandum issued by FDEP in 2006 and represents the latest guidance available from 

the State. Additional guidance has been issued by the US Environmental Protection 

Agency (USEPA) in October 12, 2007, by the Office of Wetlands, Oceans, and Watersheds 

(OWOW). The USEPA document added one element to the demonstration: “an estimate or 

projection of the time when [water quality standards] will be met,” addressed in Section 5 of 

this report. Both of these documents are provided in Appendix A. 

1.3 UNIQUENESS OF THE FLORIDA KEYS 

The Florida Keys is a chain of islands approximately 220 miles long, extending from the end 

of the Florida peninsula curving southwest toward the Dry Tortugas (see Figure 1-1). 

Consisting of 822 islands, of which about 30 are inhabited, the Florida Keys are traversed 

by U.S. Highway 1 (a.k.a., 

US 1 or Overseas 

Highway) with 19 miles of 

bridges. The Keys are 

entirely within Monroe 

County and includes the 

municipalities of 

Islamorada, Key Colony 

Beach, Layton Marathon 

and Key West. Key West 

represents about 30 

percent (24,000 people) of 

the population of Monroe 

County, which, according 

to the 2000 Census, is 

about 79,600 people. 

In general, Florida 

watersheds are 

characterized by a large 

land mass with runoff 

flowing to a small (in 

surface area, at least) 

water body. Runoff is focused to receiving waters wherein pollutants are concentrated. 

Soils allow infiltration and percolation slowing down nutrient runoff and as well, soils can 

facilitate the treatment of nutrients due the availability of available land for common 

stormwater best management practices (BMPs). Also, the BMPs can generally be 

Figure 1-1 

Florida Keys 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 1.doc Page 1-4 

monitored using a relatively small number of sampling points. Similarly, with the large 

watersheds, wastewater can be controlled using septic tanks and large regional treatment 

facilities. Septic discharges through a drainfield can be absorbed into the soils and regional 

treatment effluent can be discharged via reuse, storage, land application, deep well injection 

and in some cases, surface water discharge to receiving waters. As a result of all these 

factors, a conventional approach to pollutant controls is warranted and usually followed. 

The Florida Keys, in contrast, is a 220 miles long string of small islands surrounded by a 

very large receiving water body. As a result, runoff is not focused and pollutants are 

dispersed. Soils are such that infiltration and percolation is relatively enhanced, moving 

infiltrated runoff to nearshore waters quickly, yielding little or no nutrient entrapment or 

treatment in the soils matrix. The limited size of the land area limits the ability to place land 

intensive stormwater BMPs (such as detention or retention ponds). For wastewater, due to 

the soils, high water table and tides, septic tanks have limited treatment capability and 

“regional” systems are historically limited to small package plants. Finally, pollutant sources 

outside of the control of the local governments provide the dominant influence on the 

receiving waters of the area. In this case, unconventional approaches to pollutant controls 

are required. Additionally, because they represents a unique terrestrial and aquatic 

ecosystem, the Florida Keys have been the subject of significant regional, state and federal 

scrutiny with most aspects of growth and development reviewed at all levels. The extent to 

this scrutiny will be expanded in other sections of this report since it is this oversight that 

provides reasonable assurance that pollution control activities will be accomplished in the 

Florida Keys. 

1.4 GEOGRAPHIC EXTENT OF THE SOUTH-CENTRAL KEYS 

AREA 

The South-Central Keys Area is generally described as the islands of Boca Chica Key, 

Saddlebunch Key, Sugarloaf Key, Cudjoe Key, Summerland Key, Ramrod Key, Big Torch 

Key, Big Pine Key, Long Beach, No Name Key and Bahia Honda Key. These islands are 

within the following WBIDs: 6014C, 6013A, 6013B, 6013C, 6013D, 6012A, 6012B, 6012C, 

6012D, and 6018. Figure 1-2 illustrates the area, which is approximately 27,150 acres 

(42.4 sq miles) in size. 

For the purposes of this 

document, three receiving water 

areas are defined: 

 Bubble WBID or Halo 

Zone – from the 

coastline to 500 meters, 

within which the 

impairment has been 

defined; 

 Nearshore waters – 

those modeled waters 

from 500 meters to 

12,100 meters; and, 

Figure 1-2 

South-Central Keys Area 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 1.doc Page 1-5 

 Farfield waters – those waters beyond 12,100 meters from the coastline, the water 

quality of which is controlled by outside influences. 

1.5 STAKEHOLDER GROUP PROCESS 

In order to prepare the FKRAD, a stakeholder process was used starting in late 2006. The 

stakeholder process provided an opportunity for local, regional, state and federal 

governments (as well as other third party interest) to: understand the reasonable assurance 

process; provide data and research input into the development of the FKRAD 

documentation; and confirm that the FKRAD reasonably expresses the committed activities 

of the stakeholders. A brief description of the group is provided below. 

1.5.1 Stakeholder Group Membership 

The stakeholder group consisted of all of the local, regional, state and federal agencies as 

well as environmental and local groups interested in the Florida Keys. Table 1-1 provides a 

list of the invited stakeholder group. Each stakeholder was contacted by e-mail periodically 

to identify upcoming meetings and provide meeting presentation material, minutes of 

meetings, and other material useful to the understanding of the program. 

1.5.2 Technical Working Group 

The Technical Working Group is comprised of representative of stakeholders who are party 

to the FKRAD and technical contributors. The Technical Working Group mission statement 

is: “The mission of the Florida Keys Reasonable Assurance Documentation (FKRAD) 

Program’s Technical Working Group is to obtain information on existing and pending 

stakeholder programs required to describe and document regional water quality 

management actions that will provide reasonable assurance that existing programs will 

meet identified local goals for restoring nutrient impaired water bodies. “ 

The purpose of the Technical Working Group was to: 

1. Define guiding principles to be adopted by stakeholders for achieving the mission 

of the FKRAD; 

2. Identify nutrient impaired water bodies and the causes of impairment, document 

existing and pending stakeholder programs for reducing anthropogenic impacts 

in receiving water bodies; 

3. Identify local and regional water quality targets and aquatic ecological goals, 

describe ongoing local and regional management actions to achieve nutrient load 

reductions in the impaired water bodies; 

4. Identify procedures for monitoring and reporting the results of the management 

actions, describe proposed corrective actions, gather local information and data 

required to fill key knowledge gaps; 

5. Identify necessary education, outreach, and implementation measures for 

moving the impaired water bodies toward meeting regional goals and achieving 

FDEP water quality standards; and, 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 1.doc Page 1-6 

6. Assist in securing participation of all interested groups, individuals, and agencies 

and involving the public throughout the process. 

Copies of presentation and meeting minutes for the Technical Working Group are provided 

in Appendix H. 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 1.doc Page 1-7 

Table 1-1 

Florida Keys Reasonable Assurance Documentation (FKRAD) 

List of Stakeholders and Interested Parties 

Stakeholders – NPDES Regulated Entities 

City of Key Colony Beach * 

City of Key West * 

City of Marathon * 

Florida Department of Transportation 

Florida Keys Aqueduct Authority * 

Islamorada, Village of Islands * 

Key Largo Wastewater Treatment District * 

Monroe County * 

Monroe County Aviation Authority 

National Oceanic and Atmospheric Administration – Aerostat Facility 

U. S. Navy 

Regulatory Agencies 

Florida Department of Health – Bureau of Onsite Sewage Programs * 

Florida Department of Community Affairs * 

Florida Department of Environmental Protection * 

U. S. Army Corps of Engineers * 

U.S. Environmental Protection Agency - Region IV * 

South Florida Water Management District * 

Programs 

Everglades & Dry Tortugas National Parks * 

Florida Department of Health * 

Florida Keys Environmental Fund * 

Florida Keys National Marine Sanctuary (FKNMS) * 

Florida Keys National Wildlife Refuges – USF&WS * 

Florida Fish and Wildlife Conservation Commission 

National Marine Sanctuaries Program - NOAA * 

FKNMS Sanctuary Advisory Council * 

Other Interested Parties 

Earth Justice 

Florida Audubon Society 

Florida Keys Visitors and Convention Bureau 

Monroe County Commercial Fishermen * 

Sandra Walters Consultants, Inc. * 

Sierra Club 

Southeast Environmental Research Center (SERC) – FIU * 

South Florida/Florida Keys Program – The Nature Conservancy * 

Thousand Friends of Florida 

Isaak Walton League of America 

* Note: Member of Florida Keys National Marine Sanctuary Steering Committee 

  
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 2.doc Page 2-1 

Section 2.0 

IDENTIFICATION OF THE IMPAIRED WATERS

2.1 UNDERSTANDING OF IMPAIRMENT IN FLORIDA KEYS 

This section provides a description of the impaired waters, historical and recent information 

showing the waters to be impaired, and a consideration of the pollutants and suspected 

sources. 

2.1.1 Problem Definition 

The Bubble WBID and nearshore waters within the South-Central Keys Area are designated 

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

of Fish and Wildlife) and Outstanding Florida Waters (OFW, excluding canals). The 

operative criteria are listed, therefore, in Chapter 62-302.530(47), FAC (criteria for Class III) 

and Chapter 62.4-242(2), FAC (criteria for OFW). The 1998 303(d) Impaired Waters List 

lists “the Florida Keys” as impaired for nutrients, with no other specificity. To clarify the 

listing for impairment, more recent and other sources of data and information are considered 

below. 

2.1.2 Historical Water Quality Information 

The most comprehensive consideration of historical water quality and impairment 

information is provided by “Water Quality Concerns in the Florida Keys: Sources, Effects, 

and Solutions” (Kruczynski, Sept. 1999). Three key points made in this document on page 

2: 

“The survival of the existing Florida Keys marine ecosystem is dependent 

upon clear, low-nutrient waters...” 

“The data demonstrate that the cumulative effects of continued discharges of 

nutrient-rich wastewater and stormwater into confined and some other 

adjacent nearshore waters have degraded the water quality of those 

waters...” 

“There is evidence that the degraded water quality has adversely impacted 

other nearshore communities.” 

There are extensive references to research done in Florida Keys waters, including 

manmade canals, and the document concludes that: 

“Scientists agree that canal and other nearshore waters are affected by 

human-derived nutrients from sewage” (Executive Summary) 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 2.doc Page 2-2 

Documents related to the Florida Keys National Marine Sanctuary (e.g., Final Management 

Plan/Environmental Impact Statement, 1996) and more recent documents from the Florida 

Keys Water Quality Improvement Program (US Army Corps of Engineers, USEPA and 

SFWMD) refer to similar statements. However, none of these documents provide evidence 

that nutrient concentrations exceed a certain threshold criteria thereby yielding measurable 

impairment. 

In 1985, when the Florida Keys were made an Outstanding Florida Waters, water quality 

data were collected to define the existing ambient water quality at the point of designation. 

Data were collected at 165 stations from January to February 1985 in three areas: Bayside 

(49 stations north and northwest of the islands), Oceanside (46 stations south and 

southeast of the islands, and Canal (70 stations within the artificial waterways interior to the 

islands in canals, boat basins and marinas). Parameters measured included dissolved 

oxygen, pH, temperature, conductivity, salinity, nitrogen species, total phosphorus, and fecal 

coliform. The detection limits for total nitrogen and total phosphorus were recorded as 20.5 

μg/l and 2 μg/l, respectively. For the Bayside and Oceanside, the results for nutrients are 

provided in the insert. 

1985 FDEP OFW Water Quality Data 

Total Nitrogen (μg/l) Total Phosphorus (μg/l) 

Location Average Minimum Maximum Average Minimum Maximum

Bayside 370 130 697 14 1 54 

Oceanside 288 145 489 15 4 80 

According to Chapter 62-302.700 (Special Protection, Outstanding Florida Waters, 

Outstanding National Resource Waters): 

“(1) It shall be the Department policy to afford the highest protection to 

Outstanding Florida Waters and Outstanding National Resource Waters. No 

degradation of water quality, other than that allowed in Rule 62-4.242(2) and 

(3), F.A.C., is to be permitted in Outstanding Florida Waters and Outstanding 

National Resource Waters, respectively, notwithstanding any other 

Department rules that allow water quality lowering.” 

In practice, FDEP has defined “degradation of water quality” as noted in this rule as 

reduction of the ambient water quality identified at the time of designation. Therefore, in 

practice, the above table represents the range of nutrient water quality at the time of 

designation and the water quality that needs to be protected according to the OFW 

designation. The following table provides the estimated nutrient concentrations as a result 

of the nutrient models prepared for this document. These concentrations represent the 

ambient nutrient content of the nearshore waters in 1999. 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 2.doc Page 2-3 

1999 Baseline Nutrient Concentrations 

Total Nitrogen (μg/l) Total Phosphorus (μg/l) 

Location Average Minimum Maximum Average Minimum Maximum

Bayside 381 211 782 19 10 50 

Oceanside 159 119 275 15 6 48 

It can be seen that average total nitrogen and total phosphorus values (except Oceanside) 

exceed those of the 1985 OFW data, indicating, according to OFW criteria, a degradation of 

nutrient concentrations. 

Other information was also considered in an attempt to identify nutrient water quality targets. 

Anecdotal information and observations from FDEP staff, scientists and engineers working 

in the Keys, and other observers point out increasing problems with water clarity, 

proliferation of macrophytic and epiphytic algae in the Halo Zone and nearshore waters 

which can be linked to nutrient enrichment. 

Existing primary monitoring networks, which were designed and implemented for the 

purpose of documenting long-term water quality trends on a quarterly basis, have 

documented instances of elevated nutrient levels. However, the quarterly data, when 

combined with the marine circulation and net flow patterns in the nearshore waters of the 

Keys, cannot be used to provide data identifying a continuing or a consistent location. 

2.1.3 Impacts of External/Far Field Sources 

Historical and recent documents refer to the impacts of farfield sources in the Bubble WBIDs 

and nearshore waters of the Florida Keys. Farfield sources include outflow from the Florida 

Everglades into Florida Bay, flows from the Peace and Caloosahatchee Rivers including 

discharges from Lake Okeechobee, waters of the Gulf of Mexico (via the Loop Current 

which is impacted by nutrients from the Mississippi River),the Florida Current (between the 

Keys and Cuba) and periodic deep ocean upwelling. Table 2-1 provides a list of 

anthropogenic and non-anthropogenic sources of nutrients in the Bubble WBIDs and 

nearshore waters of the Florida Keys in comparison to those controlled by Keys 

communities. Clearly the farfield sources are not controlled by the local governments in the 

Florida Keys. 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 2.doc Page 2-4 

Table 2-1 

Issues Impacting Living Resources and 

 Water Quality in the Florida Keys 

Non-Anthropogenic 

Uncontrollable Sources 

Impacting the Keys 

Anthropogenic Sources 

Associated with Non-Keys 

Communities 

Anthropogenic Sources 

Controllable by 

Florida Keys Communities 

 Deposition of African dust 

that contains micronutrients 

and pathogens 

 Normal atmospheric 

deposition of nutrients and 

toxins 

 Deep ocean upwelling that 

creates high nitrogen loads 

at low concentrations in the 

water column 

 El Nino Cycles 

 Elevated water temperature 

that exacerbate normal 

zooxanthellae expulsion 

rates causing coral bleaching 

 Depressed water 

temperatures that cause 

hypothermic die-off of living 

coral cover 

 Lower annual rainfall that 

causes natural hypersaline 

conditions in Florida Bay 

 Boating discharges 

 Gulf of Mexico flow-through 

 Okeechobee waterway 

discharges 

 Stormwater management 

practices and discharges 

from certain public 

properties (FDOT, military 

and SFWMD parcels) 

 Wastewater management 

practices and discharges 

from certain public 

properties (FKAA, KLWTD 

and Military parcels) 

 Regional water resource 

management and flood 

control practices and 

discharges from certain 

public properties (USACE, 

SFWMD, and military 

parcels) 

 Water controls leading to 

reduced freshwater 

influences exacerbating 

hypersalinity 

 Higher annual rainfall that 

necessitates USACE to 

initiate the flood 

management discharges 

from Lake Okeechobee via 

the Okeechobee Waterway 

(a/k/a Caloosahatchee River)

 Stormwater 

management practices 

and discharges from 

private properties 

 Stormwater 

management practices 

and discharges from 

some public properties 

 Wastewater 

management practices 

and discharges from 

private properties 

 Wastewater 

management practices 

and discharges from 

some public properties 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 2.doc Page 2-5 

2.2 IMPAIRED WATERS 

The following subsections were developed using the available information on impaired 

waters in the Florida Keys. The subsections are ordered in accordance with the FDEP and 

EPA guidelines. 

Name of Waters Listed: The waters subject to this reasonable assurance document are 

the near shore waters in the South-Central Keys Area (see Figure 1-2). For the purposes of 

this document, nearshore waters include those waters that are within a boundary of 100 ± 

meters from the coastline of each island. Water Body Identification (WBID) numbers 

include: 6014C, 6013A, 6013B, 6013C, 6013D, 6012A, 6012B, 6012C, 6012D and 6018 

which are the Halo Zone WBIDs surrounding the island of Boca Chica Key, Saddlebunch 

Key, Sugarloaf Key, Cudjoe Key, Summerland Key, Ramrod Key, Big Torch Key, Big Pine 

Key, Long Beach, No Name Key and Bahia Honda Key. 

Location of Waters/Watersheds: The waters are located in Monroe County, on the 

southwestern tip of the Florida Keys. These water bodies are located within the FDEP 

South District and the South Florida Water Management District (SFWMD). 

Watershed Unit Code: Waters in the Florida Keys have been assigned a HUC code of 

03090203. 

Water Body Type: The waters subject to this document are marine, more specifically the 

Halo Zone WBIDs surrounding the islands of Boca Chica Key, Saddlebunch Key, Sugarloaf 

Key, Cudjoe Key, Summerland Key, Ramrod Key, Big Torch Key, Big Pine Key, Long 

Beach, No Name Key and Bahia Honda Key. 

Water Use Classification: The waters are classified by the state of Florida as Class III - 

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

and Wildlife. Also, excluding interior canals, all of the waters in the Florida Keys are 

considered Outstanding Florida Waters as indicated in Chapter 62-302.700(12). 

Designated Uses Not Attained: The designated use not attained for the near shore 

waters of the Florida Keys is “Propagation and Maintenance of a Healthy, Well-Balanced 

Population of Fish and Wildlife” through the violation of the nutrient rule Chapter 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 and fauna.” However, as 

noted above, the definition of impairment in this area is based on historical and anecdotal 

information as well as stakeholder experience.

Length of Impaired Waters: The South-Central Keys Area is a series of islands of 

approximately 23 miles long by about 6 miles at the widest point. The impaired waters are 

the Bubble WBIDs or Halo Zone waters surrounding the islands consisting of the first 500 

meters off the shoreline. 

Pollutant(s) of Concern: The pollutants of concern are nutrients; in particular, total 

nitrogen and total phosphorus. 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 2.doc Page 2-6 

Suspected/Documented Sources: Documented sources of nutrient enrichment in the 

near shore waters of the South-Central Keys Area include: stormwater runoff and indirect 

wastewater discharges (nonpoint sources) from two separate sources: 

 Farfield Nutrient Loads: include outflow from the Florida Everglades into Florida 

Bay, flows from the Peace and Caloosahatchee Rivers including discharges from 

Lake Okeechobee, waters of the Gulf of Mexico (via the Loop Current which is 

impacted by nutrients from the Mississippi River), the Florida Current (between the 

Keys and Cuba) and periodic deep ocean upwelling. 

 Local Nutrient Loads: Stormwater runoff is discharged to near interior canals and 

shore waters during rainfall events from existing developed areas. Wastewater 

discharges to canals and near shore waters from cesspits (failed septic tanks), 

onsite treatment facilities and small wastewater treatment facilities.

  
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 3.doc Page 3-1 

Section 3.0 

DESCRIPTION OF WATER QUALITY TARGETS

3.1 WATER QUALITY TARGETS 

This section defines the water quality targets used to evaluate the degree to which 

management activities with result in the attainment of the narrative nutrient water quality 

criterion (“an imbalance of aquatic flora and fauna”). The applicable water quality standards, 

resource targets and selected targets are discussed below. 

3.1.1 Florida Water Quality Standards 

The nearshore waters in the South-Central Area are classified as Class III (Recreation, 

Propagation and Maintenance of a Healthy, Well-Balanced Population of Fish and Wildlife) 

and Outstanding Florida Waters (OFW). These designations are discussed further in the 

Technical Information Document, Appendix A. 

For these waters, the applicable water quality standard is §62-302.530(47), FAC, which 

states: 

“(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 or total phosphorus) shall be considered 

degradation in relation to the provisions of Sections 62-302.300, 62-302.700, 

and 62-4.242, FAC.” 

(b) In no case shall nutrient concentrations of a water body be altered so as to 

cause an imbalance of natural population of aquatic flora and fauna.” 

To define impairment, Subpart (b) was the focus of the Impaired Water Rule (§62-303.353, 

FAC) in cases where nutrients are used to consider impairment: 

“Estuaries, or estuary segments, or open coastal waters shall be included on 

the planning list for nutrients if their annual mean chlorophyll a for any year is 

greater than 11 μg/l or if data indicate annual mean chlorophyll a values have 

increased by more than 50% over historical values for at least two consecutive 

years.” 

The threshold identified in this rule was not to be used as a target (§62-303.450, FAC). 

Therefore, with the nearshore waters in Florida Keys identified as impaired for nutrients, the 

applicable target was researched. 

3.1.2 Water Quality Targets for Aquatic Resources 

In an attempt to define water quality targets based on the protection or enhancement of 

aquatic resources, recent research was consulted and numerous personal contacts were 

made, the results of which are summarized by resource below. 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 3.doc Page 3-2 

Queen Conch 

The queen conch is a large marine gastropod harvested intensively 

throughout the Caribbean for its meat and shell. Conch, in the Florida Keys, 

once supported commercial and recreational fisheries, but over-harvesting 

depleted the population. Though the harvesting of conch was banned in 

Florida in 1985, conch populations have not recovered to levels that support 

exploitation. Conch tend to occur in two spatially assemblages throughout 

the Florida Keys: nearshore assemblages that congregate in nearshore 

seagrass beds and hard bottom communities, and offshore assemblages 

that occupy soft bottom communities. 

Recent studies have tried to identify stressors affecting the reproduction and 

mortality of queen conch. These studies observed that nearshore and 

offshore queen conch in the Florida Keys are subjected to oxidative stress. 

Furthermore, studies have observed retarded reproductive activity among 

nearshore queen conch. Yet, these studies failed to link the effects of 

increased nutrient levels on reproduction and mortality. Inadequate methods 

for determining conch age, variable fecundities, and studies conducted over 

long timescales are problematic variables for conch studies that do not yield 

conclusive results regarding the significance of nutrient levels on conch 

populations. 

Coral Reefs 

Reports on the Florida Keys coral reef species have raised concern about 

the continued decline of the coral reefs in nearshore and offshore waters, 

and the need to understand the causes of decline of coral populations. 

Coral reef communities, habitats for hundreds of marine species of fish and 

marine invertebrates, occur in rocky bottoms areas and are dominated by 

several species of stony corals, such as Acropora (branching corals), 

Montastrea (star corals), and Diploria (brain corals). Coral reefs also 

comprise soft corals, sponges, tunicates, and algae. Factors affecting coral 

reef development, growth, and sustenance include light transitivity, substrate 

availability, nutrient levels, salinity, temperature, sedimentation/turbidity, 

disease, and physical damage. 

Recent studies on coral reef decline have focused on the effects of 

increased nutrient levels from runoff, outfalls, and septic systems on coral 

reef development. Nitrogen levels throughout the coral reef study areas are 

adequate to sustain proper coral reef development, although the nitrogen 

cycle in coral reef systems is not well understood and should not be used to 

indicate pollution levels in coral reefs. In addition, high concentrations of 

chlorophyll-a in coral tissue are thought to be an adaptive response resulting 

from decreased light levels caused by turbidity and increased algae 

productivity. 

It is difficult to determine if there has been a conclusive decline in coverage 

of coral species because of a lack of continuity in monitoring specific sites. 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 3.doc Page 3-3 

Documented coverage estimates and trends over time were obtained from 

varying samples sizes, therefore results are not representative of coral 

species throughout the Keys. 

Sea Grasses 

Seagrass provide a number of ecological functions in the Florida Keys. 

They maintain water clarity by stabilizing benthic sediments and pulling 

nutrients out of the water column. They also provide a habitat for seadwelling creatures like fish and shellfish, provide food for many marine 

animals, and provide a nursery area for Florida’s important marine life. 

Species of seagrass found in the Florida Keys include turtle-grass (Thalassia 

testudinum), manatee-grass (Syringodium), shoal-grass (Halodule wrightii), 

paddle-grass (Halophila decipiens), star-grass (Halophila englemanni), and 

widgeon-grass (Ruppia maritima). 

As part of the Florida Keys Carrying Capacity Study, nearshore seagrass 

communities were studied to determine if temporal or spatial variation in 

seagrass communities were associated with human land use activity in the 

Florida Keys. Despite significant land development in the Florida Keys over 

the past 40 years, nearshore seagrass communities exhibited little variation. 

The results provided little evidence to support a relationship between land 

use and spatial or temporal variation of nearshore seagrass communities 

and their associated nutrient regimes throughout the Florida Keys. Despite 

visual evidence of anthropogenic effects on the near shore and offshore 

aquatic environment of the Florida Keys (prop scars and coral damage, 

among others), available reports and data are insufficient to establish a 

scientifically defensible nutrient target related to human land development, 

nutrient regimes, and nutrient effects on the seagrass communities. 

Coral Reef Fish 

Reef fishes are an essential component to the Florida Keys marine 

ecosystem that provides recreational activities for tourists and residents, and 

supports important commercial and recreational fisheries. Reef fishes 

include hundreds of species that vary in size, shape, and color, which can 

make the identification and quantification of species very difficult. One 

example of a reef fish is the parrotfish, which has become the dominant 

grazer on Caribbean reefs since the mass disease-induced die-off of the 

urchin Diadema antillarum in 1983. 

Although monitoring programs remain the best source of information about 

changes in fish species in the Florida Keys, they are not specifically linked to 

the identification of stressors, such as nutrients concentrations, and overall 

health of fish populations. Rather, studies on fish populations through the 

Florida Keys have been focused on establishing biodiversity indices that 

provide the richness and evenness of species or on the potential effects of 

fishing pressure on fish populations. Neither of these types of studies 

establishes thresholds for evaluating anthropogenic impacts on fish species 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 3.doc Page 3-4 

development. The limited data linking water quality stressors to fish 

populations and the uncertainty associated with fish biodiversity assessment 

highlight the difficulty in providing quantitative decisions regarding the effects 

of nutrient levels on fish in the Florida Keys. 

Based on this research, no aquatic resource based targets or thresholds are scientifically 

supported to define a preferred nutrient condition in the halo zone of the South-Central Area 

waters. 

3.1.3 Water Quality Targets Based on Insignificant Anthropogenic 

Increases 

The previous subsection indicated that scientifically supported targets related to the 

protection of aquatic resources are not available for the significant aquatic flora or fauna in 

the halo zone waters of the Florida Keys. For this reason, a surrogate target is considered 

for the definition of targets – that the anthropogenic loads after the achievement of the 

management activities defined by this reasonable assurance documentation cause an 

“insignificant” increase in nutrient concentrations in the halo zone above the farfield 

concentration. 

For the purposes of this document, “insignificant” means 10 μg/l for Total Nitrogen and 2 

μg/l for Total Phosphorus above natural background at 500 meters from the shore. Natural 

background is the predicted model result in the Halo Zone with all of the urban land uses 

changed to natural conditions (e.g., residential and commercial changed to forested land 

uses with no change to land uses that are already wetlands, water or forested). According 

to the model, the targets are defined as follows: 

Parameter Natural Background 

Concentration (μg/l) 

Water Quality 

Target Concentration 

@ 500 meters (μg/l) 

Total Nitrogen 

2N 195 205 

2S 125 135 

3N 205 215 

3S 128 138 

4N 211 221 

4S 131 141 

Total 

Phosphorus 

2N 10 12 

2S 6 8 

3N 10 12 

3S 6 8 

4N 10 12 

4S 5 7 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 3.doc Page 3-5 

3.1.4 Water Quality Targets Based on OFW Designation 

As noted in Section 2.0, the Florida Keys have been designated Outstanding Florida Waters 

and as such, the water quality defined at the point of designation becomes the condition 

below which degradation is not allowed (Ch. 62-302.700, F.A.C). Data from the 1985 

designation are provided below – the data and ranges represent nutrient thresholds as do 

the insignificant increases discussed above. 

1985 FDEP OFW Water Quality Data 

Total Nitrogen (μg/l) Total Phosphorus (μg/l) 

Location Average Minimum Maximum Average Minimum Maximum

Bayside 370 130 697 14 1 54 

Oceanside 288 145 489 15 4 80 

3.1.5 Water Quality Standards for Hawaii As Comparison 

Comparison of the situation in the Florida Keys to that in the State of Hawaii was considered 

as part of this program since Hawaii is the only potentially similar set receiving waters and 

watershed/hydrologic settings. 

 Common Factors include their tropical settings, lack of “upstream” flows, 

relatively small watershed areas (islands) discharging to large receiving waters. 

 Significant Differentiating Factors include the larger relative scale of the Hawaiian 

islands relative to the Keys (Kauai is about 25 miles in diameter while Key West is 

about 4 by 2 miles), the relatively farther distance to other anthropogenic nutrient 

sources, and the more pristine farfield water quality of the Pacific Ocean providing 

the boundary condition for the Hawaiian Islands. 

Chapter 11-54, Hawaii Administrative Rules, were reviewed to consider nutrient water 

quality standards for Hawaii. For the various types of waters in the Hawaiian Islands, the 

standards are listed below. 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 3.doc Page 3-6 

Table 3-1 

Summary of Hawaiian Nutrient Standards (Chapter 11-54, HAR) 

 Total Nitrogen Total Phosphorus 

Water Type Geometric 

Mean 

< 10% of 

Time 

< 2% of 

time 

Geometric 

Mean 

< 10% of 

Time 

< 2% 

of time 

Island Waters 250 520 800 50 100 150 

Estuaries 

(except Pearl 

Harbor) 

200 350 500 25 50 75 

Pearl Harbor 300 550 750 60 130 200 

Embayments 150 250 350 20 40 60 

Open Coastal 

Waters 

110 180 250 20 40 60 

Oceanic Waters 50 80 100 10 18 25 

It should be noted that according to Chapter 11-54(c) Ocean Waters, the boundary of such 

waters is outside of the 183-meter (600-foot) depth contour. For most locations within the 

Hawaiian Islands, this is about 1,600 meters (1 mile) from the coast. 

In comparison, the nutrient data for the Keys are summarized in the following tables, starting 

with the 1985 OFW data, the 1999 boundary condition data, and the 2020 Implemented 

Management Activities condition data (modeled, described in more detail in Section 4.0). 

Table 3-2 

1985 FDEP OFW Water Quality Data 

 Total Nitrogen (pg/l) Total Phosphorus (pg/l) 

Location Average Minimum Maximum Average Minimum Maximum

Bayside 370 130 697 14 1 54 

Oceanside 288 145 489 15 4 80 

Table 3-3 

1999 Baseline Nutrient Concentrations 

 Total Nitrogen (pg/l) Total Phosphorus (pg/l) 

Location Average Minimum Maximum Average Minimum Maximum

Bayside 381 211 782 19 10 50 

Oceanside 159 119 275 15 6 48 

Table 3-4 

2020 Simulated Nutrient Condition with Implemented Management Actions 

 Total Nitrogen (pg/l) Total Phosphorus (pg/l) 

Location Average Minimum Maximum Average Minimum Maximum

Bayside 346 172 756 9 7 12 

Oceanside 126 114 140 6 5 9 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 3.doc Page 3-7 

In comparison, the mean or average total nitrogen values are slightly larger than the Pearl 

Harbor values, with the 1987 OFW values also larger than the Pearl Harbor. The total 

phosphorus values for the OFW and Baseline condition are slightly larger than the Hawaiian 

open ocean standard (but less than any other listed) and for the 2020 condition, are less 

than the Hawaiian open ocean values. From this limited comparison, the total nitrogen 

targets are similar to Hawaii and the total phosphorus targets are lower than Hawaii, even 

though the Keys represent a different background condition (not pristine). Further, the Keys 

targets are set at 500 meters from the coast and Hawaii’s are set at 183 meters of depth 

(not experienced in the Florida Keys) which translates in Hawaii to a minimum of 1,600 

meters (1 mile) away from the island. 

3.2 RESTORATION OF THE DESIGNATED USES OF THE 

IMPAIRED WATERS 

The nutrient concentrations of the Bubble WBIDs (or Halo Zone) and nearshore waters are 

dominated by the farfield anthropogenic and natural nutrient loading, outside of the 

influence of the agencies in the Florida Keys. The participants in this reasonable assurance 

documentation, as shown below, will significantly reduce the additive anthropogenic 

nutrients due to wastewater and stormwater loads. As a result, the additive concentration in 

the Halo Zone will be insignificant once the management activities defined herein are 

completed. While the influences of the islands of the Florida Keys will be minimized by 

these activities, continuing work on the Everglades, Peace River, Caloosahatchee River, 

Mississippi River and other outside controlling factors is needed to return the water quality in 

the Keys to historical conditions. 

  
Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-1 

Section 4 

DESCRIPTION OF PROPOSED MANAGEMENT

ACTIONS TO BE UNDERTAKEN

4.1 NAMES OF THE RESPONSIBLE PARTICIPATING ENTITIES 

There are a total of five stakeholders participating in the South-Central Keys Area Reasonable 

Assurance documentation process including: 

 Monroe County (WBIDs 6012A1A/B/C/D, 6013A/B/C/D, 6014C, and 6018) 

 United States Navy (WBID 6014C) 

 Florida Department of Transportation (WBIDs 6012A1A/B/C/D, 6013A/B/C/D, 6014C, 

and 6018) 

 Florida State Parks System (WBID 6018) 

Exhibit 4-1 at the end of this section provides a brief summary of each of these stakeholders 

and contains the contact information for the individual who has executed their stakeholder 

agreement, their Technical Working Group Representative, and in some cases their facility 

manager. 

4.2 PROPOSED MANAGEMENT ACTIVITIES DESIGNED TO 

RESTORE WATER QUALITY 

As previously discussed, the Florida Keys are unlike any other watershed in Florida in terms of 

the relationship of watersheds to receiving waterbodies, dispersion vs. concentration of 

nutrients, and the predominance of farfield sources on local water quality. Consequently, there 

are a number of important concepts that need to be understood relative to the management 

actions being proposed in the South-Central Keys Area: 

 Water quality in the nearshore waters (those areas seaward of a point approximately 

100 meters off the shoreline) is dominated by farfield sources which are a combination 

of naturally occurring nutrient loads and anthropogenic sources located outside of the 

Florida Keys. 

 Farfield sources are not within the control of the residents of the Florida Keys. 

 Water quality in the Halo Zone waters (the area from the beach to a line approximately 

100 meters off the shoreline) are incrementally affected by a combination of natural 

stormwater discharges originating on undeveloped areas and anthropogenic discharges 

from developed land with loads attributable to wastewater and stormwater management 

practices from developed properties. 

 Water quality in the Halo Zone waters is also incrementally affected, though to a much 

lesser degree, by nutrients discharged via stormwater from existing natural areas. 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-2 

 Management actions being proposed in this document focus specifically on the 

reduction or elimination of the anthropogenic nutrient loads being discharged to the Halo 

Zone waters in the defined “bubble” WBIDs. 

 No attempt to reduce farfield impacts has been incorporated into this document as those 

strategies are outside of the implementation abilities of the governments of the Florida 

Keys. 

Management activities have been classified into three different categories: wastewater 

management practices; stormwater management practices; and regulatory programs. The 

implemented and anticipated management actions are summarized in Table 4-1. 

Table 4-1 

General Management Actions 

Wastewater Management 

Practices 

Stormwater Management 

Practices Regulatory Programs 

 Elimination of Cesspits 

 Centralized Wastewater 

Services 

 Upgraded Privately Owned 

Wastewater Systems 

 Class V Deep Injection Well 

for Disposal of Wastewater 

Effluent (Replacing Existing 

Ocean Outfall) 

 Marine Pump-Out Service for 

Moored Boats to Reduce 

Illicit Discharges 

 Retrofitting Existing Drainage 

Systems with Stormwater 

Treatment prior to Outfall to 

Halo Zone Waters 

 Retrofitting Existing Drainage 

Systems with Stormwater 

Treatment and Stormwater 

Disposal Wells (No Direct 

Outfall to Halo Zone) 

 Incorporation of Treatment 

Components in New 

Transportation Projects 

 Designation as an “Area of 

Critical State Concern” 

 Local Development and 

Redevelopment Regulations 

 Enforcement of Chapter 99-

395 Requirements by FDEP 

and FDOH 

Refer to Exhibit 3 Refer to Exhibit 4 Refer to Appendix A 

Cumulative Nutrient Loading Reduction Potential: The collective effect of the proposed and 

pending wastewater and stormwater management actions represent a significant effort for 

removing the 1999 baseline anthropogenic stormwater nutrient load that was identified for the 

South-Central Keys Area. Continuing application of proposed management actions will also limit 

the additional nutrient loading associated with the anticipated future new growth and 

redevelopment within the South-Central Keys Area. 

4.3 SCOPE OF MANAGEMENT ACTIVITIES 

Management actions associated with provision of central wastewater collection, treatment and 

disposal are targeted across the entire South-Central Keys Area. 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-3 

Table 4-2 

South-Central Keys Area Management Actions 

Management Action EDUs 

Served 

% of Total 

EDUs 

(11,526 EDUs) 

Area 

Served 

(Acres) 

IMPLEMENTED/OPERATIONAL MANAGEMENT ACTIONS

 Centralized Wastewater Services 3,423 29.7% 

 Class V Deep Injection Well for Disposal 

of Wastewater Effluent (Replacing 

Existing Ocean Outfall) 

0 0.0% 

 Marine Pump-Out Service for Moored 

Boats to Reduce Illicit Discharges 0 0.0% 

PLANNED FUTURE MANAGEMENT ACTIONS

 Elimination of Cesspits* 439 3.8% 

 Elimination of Septic Tank Systems** 6,401 55.5% 

 Elimination of Private WWTPs*** 3,384 29.4% 

 Centralized Wastewater System with BAT 

Treatment Facilities 355 3.1% 

 Centralized Wastewater System with 

AWT Treatment Facilities 10,753 91.7% 

 * Conversion to ATUs or Centralized Wastewater Services 

** Connection to Central Sewer System and Formal Abandonment of Septic Tank System 

*** Connection to Central Sewer System with BAT or AWT Treatment 

All of the implemented/operational management actions identified in Table 4-2 have been, or 

will be, implemented through the direct involvement of individual stakeholders or the collective 

actions of multiple stakeholders working together as shown by participation in the plan as a 

signatory member. 

4.4 ESTIMATED POLLUTANT LOAD REDUCTION FROM THE 

IMPLEMENTATION OF INDIVIDUAL MANAGEMENT ACTIONS 

Nutrient loading to the Halo Zone waters has continued to increase with growth of residential 

and commercial properties through 2007. A number of Monroe County projects, being 

implemented through a collaborative agreement with the Florida Keys Aqueduct Authority, will 

eliminate many of the baseline OSTDS discharges through connection with the central facilities. 

Similarly, the Navy has committed to upgrading its existing secondary WWTP to produce AWT 

quality effluent. These actions will collectively achieve a significant reduction of nutrient 

discharges to the halo zone waters. Baseline nutrient loading, reductions attributable to 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-4 

improved and new management practices and current and future nutrient loading estimates are 

generally shown in Table 4-3 and discussed in the following subsections. 

Table 4-3 

Estimated Nutrient Loadings in the South-Central Keys Area 

Total Anthropogenic Nutrient Loads 

Total 

Nitrogen 

(lbs/year) 

Total 

Phosphorus 

(lbs/year) 

1999 Baseline 

Condition 200,668 46,628 

July 1, 2007 200,668 46,628 

July 1, 2010 125,785 24,778 

July 1, 2020 14,835 4,945 

* Includes reductions from existing and anticipated stormwater management BMPs

4.4.1 Baseline Nutrient Loading 

Benchmark annual nutrient loadings for the South-Central Keys Area, calculated from the 

CCIAM* GIS coverages, are based upon the number of EDUs, their estimated daily flows 

and the effluent characteristics of their wastewater treatment methods as summarized in 

Exhibits 4-2 and 4-3. These individual nutrient loads have been aggregated by WBID and 

source type, and are summarized in Table 4-4: 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-5 

Table 4-4 

Baseline Annual Nutrient Loadings 

WBID 

Estimated Annual Wastewater 

Load (lbs/year) 

Estimated Annual 

Anthropogenic Stormwater 

Load (lbs/year) 

Total 

Nitrogen 

Total 

Phosphorous 

Total 

Nitrogen 

Total 

Phosphorous 

6012A 30,009 8,943 21,362 3,353 

6012C 193 58 2,842 460 

6012D 346 104 1,280 205 

6012E 1,175 343 3,113 511 

6013A 11,971 3,558 22,724 3,806 

6013B 632 188 843 132 

6013C 28,183 8,162 15,223 2,449 

6013D 82 25 787 128 

6014C 25,498 7,532 23,910 4,566 

6018 2,388 716 3,085 480 

TOTALS 209,218 64,609 30,645 4,427 

Source: Florida Keys Carrying Capacity Study, Deliverable 8, Water Module, CCIAM GIS 

coverages for wastewater management practices and land uses 

Note: * indicates loads to WBIDs along 7-mile Bridge 

4.4.2 Nutrient Removals by Proposed Management Activities 

Nutrient removal rates for the proposed management practices are based on a combination of 

local performance data from facilities that have been installed and operated in the Florida Keys, 

treatment characteristic that have been adopted in previous wastewater and stormwater master 

plans, and available data from outside the Keys. 

 Wastewater Treatment – The treatment characteristics for the wastewater management 

practices, discussed in Exhibit 4-2, are generally based on local monitoring data 

collected at facilities in the Florida Keys and the findings and recommendations of the 

Monroe County Sanitary Wastewater Master Plan. 

 Stormwater Treatment – A wide variety of structural and nonstructural stormwater 

management practices were identified for potential use in the Monroe County 

Stormwater Management Master Plan, and are summarized in Exhibit 4-3. 

 Disposal Wells – The “polishing” benefit of the shallow (at least 90 deep and cased to a 

minimum 60 foot depth) effluent disposal wells is based upon limited in-situ testing of 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-6 

their treatment characteristics in the Florida Keys. The Key Colony Beach investigation 

(Pennsylvania State University, 1999) indicates that there is virtually no attenuation of 

Total Nitrogen concentrations, a limited reduction of Total Phosphorus concentrations, 

and suggests that this reduction would disappear as the receptor sites in the limestone 

are saturated. Conversely, investigation of deep (cased to a minimum of 2,000 foot 

depth) effluent wells (FDEP UIC Section, 2007) indicated virtually zero detectable return 

flows. 

 Other Management Actions – A number of other non-structural management actions 

(public education activities, consumer information programs, land use planning, vehicle 

use reduction and sharing programs, and routine pavement surface maintenance) are 

recognized as being beneficial with respect to reducing anthropogenic nutrient loads 

discharged to the halo zone waters. However, these practices have not been included in 

Table 4-5 as their nutrient reduction benefits have not been quantified. 

4.4.3 Estimated Nutrient Load Reductions 

Documentation of the estimated pollutant load reduction and other benefits are anticipated from 

implementation of individual management actions. Specific pollutant reductions have been 

documented for some of the individual management actions developed in response to water 

quality issues in the watershed, as well as established water resource management actions. 

The Stakeholders Group is confident that this document provides reasonable assurance that 

water quality target will be met in the watershed because the plan specifically removes/reduces 

the known anthropogenic sources of the pollutants of concern. 

Table 4-5 presents a summary of the proposed and implemented management actions: 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-7 

Table 4-5 

Summary of Estimated Nutrient Load Reductions for 

Proposed and Implemented Management Practices 

WBID Management Action 

Estimated Total 

Nitrogen Load 

Reduction 

(lbs/year) 

Estimated Total 

Phosphorous 

Load Reduction 

(lbs/year) 

Actual or 

Anticipated 

Operational Date 

IMPLEMENTED MANAGEMENT PRACTICES 

6013A-N 

Construction of the Bay Point central sanitary sewer 

system to serve 66 EDUs on with an AWT (5-5-3-1) 

treatment facility and nominal 90-foot effluent 

disposal well [Monroe County/FKAA] 

408 120 2007 

6013A-S 

Construction of the Bay Point central sanitary sewer 

system to serve 346 EDUs on with an AWT (5-5-3-

1) treatment facility and nominal 90-foot effluent 

disposal well [Monroe County/FKAA] 

2,147 632 2007 

PROPOSED FUTURE MANAGEMENT PRACTICES 

6013B-N 

Construction of the Middle Lower Keys central 

sanitary sewer system to serve 66 EDUs on with an 

AWT (5-5-3-1) treatment facility and nominal 90-foot 

effluent disposal well [Monroe County/FKAA] 

538 103 June 2009 

6013C-N 

Construction of the Middle Lower Keys central 

sanitary sewer system to serve 565 EDUs on with 

an AWT (5-5-3-1) treatment facility and nominal 90-

foot effluent disposal well [Monroe County/FKAA] 

4,580 1,116 June 2009 

6013C-S 

Construction of the Middle Lower Keys central 

sanitary sewer system to serve 2,860 EDUs on with 

an AWT (5-5-3-1) treatment facility and nominal 90-

foot effluent disposal well [Monroe County/FKAA] 

19,521 5,665 June 2009 

6013D-N 

Construction of the Middle Lower Keys central 

sanitary sewer system to serve 9 EDUs on with an 

AWT (5-5-3-1) treatment facility and nominal 90-foot 

effluent disposal well [Monroe County/FKAA] 

70 21 June 2009 

6014C-N 

Construction of the South Lower Keys central 

sanitary sewer system to serve 936 EDUs on with 

an AWT (5-5-3-1) treatment facility and nominal 90-

foot effluent disposal well [Monroe County/FKAA] 

7,605 2,124 June 2009 

6014C-S 

Construction of the South Lower Keys central 

sanitary sewer system to serve 686 EDUs on with 

an AWT (5-5-3-1) treatment facility and nominal 90-

foot effluent disposal well [Monroe County/FKAA] 

4,027 1,557 June 2009 

6014C-N 

Upgrading of the existing Boca Chica Airfield 

Secondary WWTP to AWT (5-5-3-1) treatment 

facility [U. S. Navy] 

4,714 1,387 No Later Than 

June 30, 2010 

6014C-S 

Upgrading of the existing Boca Chica Airfield 

Secondary WWTP to AWT (5-5-3-1) treatment 

facility [U. S. Navy] 

4,113 1,209 No Later Than 

June 30, 2010 

6012A-N 

Construction of the North Lower Keys central 

sanitary sewer system to serve 2,815 EDUs on with 

an AWT (5-5-3-1) treatment facility and nominal 90-

foot effluent disposal well [Monroe County/FKAA] 

19,640 5,737 December 2010 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-8 

WBID Management Action 

Estimated Total 

Nitrogen Load 

Reduction 

(lbs/year) 

Estimated Total 

Phosphorous 

Load Reduction 

(lbs/year) 

Actual or 

Anticipated 

Operational Date 

6012A-S 

Construction of the North Lower Keys central 

sanitary sewer system to serve 813 EDUs on with 

an AWT (5-5-3-1) treatment facility and nominal 90-

foot effluent disposal well [Monroe County/FKAA] 

5,876 1,724 December 2010 

6012C-N 

Construction of the North Lower Keys central 

sanitary sewer system to serve 24 EDUs on with an 

AWT (5-5-3-1) treatment facility and nominal 90-foot 

effluent disposal well [Monroe County/FKAA] 

164 48 December 2010 

6012D-S 

Construction of the North Lower Keys central 

sanitary sewer system to serve 43 EDUs on with an 

AWT (5-5-3-1) treatment facility and nominal 90-foot 

effluent disposal well [Monroe County/FKAA] 

291 84 December 2010 

6012E-N 

Construction of the North Lower Keys central 

sanitary sewer system to serve 94 EDUs on with an 

AWT (5-5-3-1) treatment facility and nominal 90-foot 

effluent disposal well [Monroe County/FKAA] 

1,003 286 December 2010 

SOUTHCENTRAL 

KEYS AREA 

TOTAL NUTRIENT REDUCTIONS 74,697 21,813 

4.4.4 Assessment of Water Quality Benefits 

Quantification of the actual water quality benefits achieved in the receiving waters directly 

attributable to the reduction of the wastewater and anthropogenic stormwater nutrient loads, 

expressed in terms of water column and groundwater concentrations of nutrients, is technically 

difficult due to flushing characteristics of the surficial aquifers and the canal systems and the 

dynamic circulation patterns in the nearshore waters as discussed in Exhibit 4-4. Specific 

modeling procedures are presented in detail in Appendix F. 

Simulated Nutrient Concentrations 

WBID models zones 2, 3 and 4 were used to estimate relative nutrient concentrations in the 

South-Central Keys Area for the 1999 Baseline and projected June 30, 2010 nutrient loading 

conditions for the Halo Zone (Bubble WBID) waters and the 15 progressive cells that 

cumulatively extend to 12,100 meters off the shoreline. Simulation results are presented in 

Figures 4-1 and 4-2 where the dashed red lines represent 1999 Baseline nutrient loading 

conditions and the solid black lines represent the projected June 30, 2010 conditions. 

Nutrient Concentration Improvements 

The initial assessment of these simulation results focused on the changes between the model 

boundary and Halo Zone values for both the baseline and proposed the relationships between 

the baseline and projected June 30, 2010 loadings. The relative nutrient concentrations indicate 

that the proposed management actions will potentially produce: 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-9 

 Significant Total Nitrogen concentration reductions in the Halo Zone waters that 

represent:

 A reduction of 1-4 μg/l (approximately 1.5%) from 1999 conditions; 

 A future TN condition that is only 1-14 μg/l above the external TN boundary 

conditions of the WBID model; and 

 The net increase in TN above the natural background concentration within 500 

meters of the coastline is less than the water quality target increase of 10 μg/l for 

all of the models in the South Central Keys Area. 

 Significant Total Phosphorus concentration reductions in the Halo Zone waters that 

represent:

 A reduction of 0 - 2 μg/l (approximately 9.8%) from 1999 conditions; and 

 A future TP condition that is only 0 - 2 μg/l above the external TN boundary 

conditions of the WBID model and 

 The net increase in TP above the natural background concentration within 500 

meters of the coastline is equal to or less than the water quality target increase 

of 2 μg/l for all of the models in the South Central Keys Area. 

The results of this analysis are summarized in Table 4-6. 

Table 4-6 

Simulated Concentrations in the South-Central Keys Area Halo Zone 

Nutrient Model 

Halo Zone 

Natural 

Conditions 

Concentration 

(μg/l) 

1999 

Baseline 

Concentration 

at 500 meters 

(μg /l) 

Concentration 

After 

Management 

Actions at 

500 meters 

(μg /l) 

Water Quality 

Target 

(μg /l) 

Total 

Nitrogen 

2N 195 206 198 205 

2S 125 141 134 135 

3N 205 207 206 215 

3S 128 133 130 138 

4N 211 214 212 221 

4S 131 132 131 141 

Total 

Phosphorus 

2N 10 13 12 12 

2S 6 10 8 8 

3N 10 11 11 12 

3S 6 7 6 8 

4N 10 10 10 12 

4S 5 6 5 7 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-10 

Figure 4-1 

Simulated Nutrient Concentrations 

South-Central Keys (Model 2N) 

Model 2N - TN Profile

0.150

0.170

0.190

0.210

0.230

0.250

0.270

0.290

-2,000 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000

Distance from Shoreline WBID (meters)

TN (mg/l)

1999

2010

Model 2N - TP Profile

0.000

0.010

0.020

0.030

0.040

-2,000 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000

Distance from Shoreline WBID (meters)

TP (mg/l)

1999

2010
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-11 

Figure 4-2 

Simulated Nutrient Concentrations 

South-Central Keys (Model 2S) 

Model 2S - TN Profile

0.00

0.05

0.10

0.15

0.20

-2,000 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000

Distance from Shoreline WBID (meters)

TN (mg/l)

1999

2010

Model 2S - TP Profile

0.000

0.005

0.010

0.015

0.020

0.025

-2,000 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000

Distance from Shoreline WBID (meters)

TP (mg/l)

1999

2010
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-12 

Figure 4-3 

Simulated Nutrient Concentrations 

South-Central Keys (Model 3N) 

Model 3N - TN Profile

0.18

0.19

0.20

0.21

0.22

0.23

0.24

-2,000 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000

Distance from Shoreline WBID (meters)

TN (mg/l)

1999

2010

Model 3N - TP Profile

0.006

0.007

0.008

0.009

0.010

0.011

0.012

-2,000 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000

Distance from Shoreline WBID (meters)

TP (mg/l)

1999

2010
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-13 

Figure 4-4 

Simulated Nutrient Concentrations 

South-Central Keys (Model 3S) 

Model 3S - TN Profile

0.10

0.11

0.12

0.13

0.14

0.15

0.16

-2,000 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000

Distance from Shoreline WBID (meters)

TN (mg/l)

1999

2010

Model 3S - TP Profile

0.000

0.002

0.004

0.006

0.008

0.010

0.012

-2,000 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000

Distance from Shoreline WBID (meters)

TP (mg/l)

1999

2010
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-14 

Figure 4-5 

Simulated Nutrient Concentrations 

South-Central Keys (Model 4N) 

Model 4N - TN Profile

0.16

0.17

0.18

0.19

0.20

0.21

0.22

0.23

0.24

-2,000 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000

Distance from Shoreline WBID (meters)

TN (mg/l)

1999

2010

Model 4N - TP Profile

0.006

0.007

0.008

0.009

0.010

0.011

0.012

0.013

0.014

-2,000 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000

Distance from Shoreline WBID (meters)

TP (mg/l)

1999

2010
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-15 

Figure 4-6 

Simulated Nutrient Concentrations 

South-Central Keys (Model 4S) 

Model 4S - TN Profile

0.10

0.11

0.12

0.13

0.14

0.15

0.16

0.17

0.18

-2,000 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000

Distance from Shoreline WBID (meters)

TN (mg/l)

1999

2010

Model 4S - TP Profile

0.002

0.003

0.004

0.005

0.006

0.007

0.008

0.009

0.010

-2,000 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000

Distance from Shoreline WBID (meters)

TP (mg/l)

1999

2010
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-16 

4.5 OTHER BENEFITS ANTICIPATED FROM IMPLEMENTATION 

OF INDIVIDUAL MANAGEMENT ACTIONS 

4.5.1 Modeled Canals 

To consider the potential improvements that could be experienced in the canals of the Florida 

Keys as a result of the management activities, ten representative canals were modeled using 

the simulation techniques used in the Florida Keys Carrying Capacity Study (FKCCS). 

The residential canals that were previously modeled in the FKCCS project in 2002 were revised 

to incorporate newer data and results from the WTFM. This included the following ten canals 

scattered throughout the Keys: 

 50 Key Largo 

 69 Rock Harbor 

 70 Rock Harbor 

 117 Plantation Key 

 152 Lower Matecumbe Key 

 204 Marathon 

 208 Marathon 

 246 Marathon 

 288 Big Pine Key 

 339 Little Torch Key 

In the FKCCS work, canal segments were defined for each canal based upon geometry, 

connectivity and tidal connection. Canals were divided into segments of approximately equal 

length (roughly 150 feet, more or less), but segment lengths were varied to accommodate 

canal geometry, branches and turns. 

Canal segment drainage areas were delineated based on the previously defined canal 

segments overlaid on the 1999 digital orthographic quarter-quads (DOQQs) aerials. Roads 

were frequently used to delineate drainage divides and the proximity of adjacent canals or 

other water bodies were often used to estimate split areas between the canal of interest and 

the adjacent canal/water body. Unfortunately, the original delineations had been developed 

using the GIS parcel coverage which suffers from projection errors as discussed earlier in 

this report. The original delineations could still be used for the wastewater load assessment 

and are stored in the Access database as a table [Canal_EDU]. A second set of delineations 

was developed based on the FLUCCS coverage and aerials for land use/stormwater loading 

assessment and is stored in the MS Access© database as a table [Canal_LU]. 

In the FKCCS project, receiving water discharge zone segments (mixing zones) were 

defined for each of the 10 representative canals. Those discharge zones were developed 

using a 250-foot radial distance from the outlet of each canal. The radial line was trimmed 

where it intersected the shoreline or other obstruction and was used to represent the 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-17 

boundary between the nearshore water and the end of the discharge zone associated with 

the canal. It was assumed that the canal would not affect water quality beyond 250 feet from 

its outlet. The water quality at that boundary (Cell 0 of the large scale model) was used to 

characterize the quality of the source water during flood tides. The nearshore values for TN 

and TP were selected for each canal by taking the value computed by the large scale model 

for Cell 0 of the appropriate Model Zone. Table 4-7 below lists the modeled canals and their 

associated Model Zone from the large scale model.

Table 4-7 

Modeled Canals and Model Zones 

Canal ID Canal Location 

Model 

Zone 

50 Key Largo 9S 

69 Rock Harbor 9S 

70 Rock Harbor 9N 

117 Plantation Key 8N 

152 Lower Matecumbe Key 8N 

204 Marathon 5S 

208 Marathon 5S 

246 Marathon 5S 

288 Big Pine Key 4N 

339 Little Torch K 4S 

Figure 4-7 

Modeled Canal Locations 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-18 

Canals were modeled with the same algorithm implemented in the larger scale WTFM, and 

were taken from the FKCCS project essentially unaltered with the exception of the loading 

data which was updated based on the Access database load projections. The predicted 

concentrations from the large scale model for Cell 0 were used as the boundary 

concentrations at the edge of the mixing zone for each canal model. An example of a 

modeled canal is shown in Figure 4-8. 

Figure 4-8 

Example Canal Model 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-19 

Figure 4-9 

Modeled Canals (Upper Keys) 

Figure 4-10 

Modeled Canals (Mid/Lower Keys) 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-20 

The ten canal models were run with both 1990 and projected 2020 nutrient loads to evaluate 

how nutrient concentrations within the canal segments are expected to change due to the 

proposed management actions. Generally, all of the canal models show significant 

improvements in nutrient concentrations attributable to identified management actions. 

Changes in Canal 50 are summarized as an example of anticipated improvements. The 

results for all ten canal models are presented in the Technical Reference Document.

Canal 50 Case Study 

 

Canal 50 is located on the Atlantic 

side of Key Largo and has relatively 

simple canal geometry. The main 

canal segment is approximately 

1,600 feet long with a general northsouth orientation. The canal 

includes three short lateral branches 

on the east side of the main canal as 

shown in Figure 4-11. 

Figure 4-11: 

Configuration of Canal 50 

Comparison of the 1990 vs. 2010 Total Nitrogen profiles in the canal, as shown in Figure 

4-12 and summarized in Table A4-8. Differences in the modeling results between the two 

scenarios include: 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-21 

 Changes at the mouth of the canal is minimal, approximately 200 μg/l, because this is 

the area of the canal where the tidal exchange occurs and where maximum flushing 

rates are observed 

 The largest improvements in of TN, approximately 55% reductions, occur at the ends of 

the canal segments where marginal flushing typically occurs. 

 In Canal 50 the improvement at the end of branch B is about 40% reduction in TN, 

which is comparable to the improvement in the midpoint of the main branch of the canal. 

Table 4-8 

Total Nitrogen Concentrations and Differences in Canal 50 

Location 1999 Scenario 

Concentration 

2010 Scenario 

Concentration 

Concentration 

Change 

Percent TN 

Reduction 

Canal Mouth 200 μg/l 130 μg/l -70 μg/l 35% 

End of Branch A 340 μg/l 160 μg/l -180 μg/l 53% 

End of Branch B 280 μg/l 170 μg/l -110 μg/l 39% 

End of Branch C 420 μg/l 180 μg/l -240 μg/l 57% 

End of Main Branch 480 μg/l 220 μg/l -260 μg/l 55% 

Figure 4-12: 

Total Nitrogen Concentrations in Canal 50 

Similarly, comparison of the 1990 vs. 2010 Total Phosphorus profiles in the canal is shown 

in Figure 4-13 and summarized in Table 4-9. Differences in the modeling results between 

the two scenarios indicate similar the same general trends as the TP, but at significantly 

elevated improvement levels 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-22 

 Changes at the mouth of the canal is minimal, approximately 20 μg/l, because this is the 

area of the canal where the tidal exchange occurs and where maximum flushing rates 

are observed 

 The largest improvements in of TN, approximately 80% reductions, occur at the ends of 

the canal segments where marginal flushing typically occurs. 

 In Canal 50 the improvement at the end of branch B is about 70% reduction in TN, 

which is comparable to the improvement in the midpoint of the main branch of the canal. 

Table 4-9 

Total Nitrogen Concentrations and Differences in Canal 50 

Location 1999 Scenario 

Concentration 

2010 Scenario 

Concentration 

Concentration 

Change 

Percent TN 

Reduction 

Canal Mouth 28 μg/l 8 μg/l -20 μg/l 83% 

End of Branch A 68 μg/l 10 μg/l -58 μg/l 85% 

End of Branch B 44 μg/l 14 μg/l -30 μg/l 68% 

End of Branch C 86 μg/l 16 μg/l -70 μg/l 81% 

End of Main Branch 99 μg/l 22 μg/l -77 μg/l 78% 

Figure 4-13 

Total Phosphorous Concentrations in Canal 50 

The Simple transport models were developed for the ten canals that were previously 

modeled in the Florida Keys Carrying Capacity Study (URS Corporation, 2002) in order to 

assess the accumulation of nutrients in canals in the Keys and to estimate their transport 

within the canals and subsequent discharge to nearshore waters. 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-23 

 Canal segments were defined for each canal based upon geometry, connectivity and 

tidal connection. Canals were divided into segments of approximately equal lengths, 

roughly 150 feet, and segment lengths were varied to accommodate canal geometry, 

branches and turns. 

 Canal segment drainage areas were delineated based on the previously defined canal 

segments overlaid on the 1999 digital orthographic quarter-quads (DOQQs) aerials. 

Roads were frequently used to delineate drainage divides and the proximity of adjacent 

canals or other water bodies were often used to estimate split areas between the canal 

of interest and the adjacent canal/water body. 

 Unfortunately, the original delineations were developed using the GIS parcel coverage 

which suffers from projection errors as discussed earlier in this report. The original 

delineations could still be used for the wastewater load assessment and are stored in 

the Access database as a table [Canal_EDU]. 

 These models focused on nutrient mass and calculated concentrations based on the 

nutrient mass and the simulated model segment volumes at any time step. Following 

the “conservative dictum” of the study, the nutrients were treated as conservative, 

neutral buoyant substances that did not change chemical forms and were assumed to 

be adequately represented as TN and TP. 

 Receiving water discharge zone segments (mixing zones) were defined for each of the 

10 representative canals using a 250-foot radial distance from the outlet of each canal. 

The radial line was trimmed where it intersected the shoreline or other obstruction and 

was used to represent the boundary between the nearshore water and the end of the 

discharge zone associated with the canal. 

 It was assumed that the canal would not affect water quality beyond 250 feet from its 

outlet. The water quality at that boundary (Cell 0 of the large scale model) was used to 

characterize the quality of the source water during flood tides. The nearshore values for 

TN and TP were selected for each canal by taking the value computed by the large 

scale model for Cell 0 of the appropriate Model Zone. Table # below lists the modeled 

canals and their associated Model Zone from the large scale model. 

The ten canals selected by Monroe County as being “representative” of the majority of the 

canals scattered throughout the Keys included: 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-24 

Table 4-10 

Modeled Canals and Model Zones 

Monroe County 

Canal Inventory Number 

Key on which 

Canal is Located 

FKRAD 

Model Zone 

50 Key Largo 9S 

69 Rock Harbor 9S 

70 Rock Harbor 9N 

117 Plantation Key 8N 

152 Lower Matecumbe Key 8N 

204 Marathon 5S 

208 Marathon 5S 

246 Marathon 5S 

288 Big Pine Key 4N 

339 Little Torch Key 4S 

4.5.2 Additional Benefits 

The physical and operational nature of the proposed management actions will provide 

additional benefits, beyond reduction of nutrient concentrations, which are anticipated to 

include: 

 Ancillary reduction of other (non-nutrient) pollutants 

 Trash collection/removal 

 Leaf collection and net pollutant load reduction 

 Potential reduction of Inflow to the wastewater collection system 

 Improvement of ambient Halo Zone water quality 

 Improvement of ambient Canal water quality 

4.6 AGREEMENTS COMMITTING PARTICIPANTS TO THE 

MANAGEMENT ACTIONS 

Copies of the written agreements committing participants to the management actions described 

in this section are contained in the South-Central Keys Area Stakeholders Agreement.

The stakeholders identified in this agreement have the ability to reduce the anthropogenic loads 

generated within their service areas that discharge to the Halo Zone waters in the bubble 

WBIDs adjacent to their service area. It is important to note that these stakeholders have no 

ability to – or responsibility for – regulating or reducing the farfield pollutant sources or otherwise 

moderating the water quality of the nearshore waters. 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-25 

4.7 ASSESSMENT OF FUTURE GROWTH AND NEW SOURCES 

The potential for growth of anthropogenic sources is generally believed to be limited due to the 

regulatory overlay of multiple Federal, State regional and local programs and plans, combined 

with the lack of raw land and the overall cost of living in the Florida Keys. 

4.7.1 Future Growth Potential 

Growth is limited in South-Central Keys Area by a number of factors including: 

 Available Developable Land 

 Availability of Utilities 

 Growth Management Elements of the Comprehensive Plan 

 Rate of Growth Ordinance (ROGO) 

AVAILABLE DEVELOPABLE LAND 

An obvious constraint on growth potential in the South-Central Keys Area is the availability of 

developable raw land. Most of the developable land has already been developed but a limited 

opportunity exists with the redevelopment of existing properties. 

AVAILABILITY OF UTILITIES 

There are no local supplies of raw water in the South-Central Keys Area and the areas water is 

pumped from Florida Keys Aqueduct Authority’s well field located in the southern tip of 

peninsular Florida. Consumptive use allocation of available raw water supplies has recently 

been capped by SFWMD. Water supply availability from SFWMD is not an absolute constraint 

to future development in the South-Central Keys Area. Growth can be facilitated by much more 

expensive treatment of brackish and saline waters. 

Wastewater service, through the identified joint Monroe County/FKAA projects, can 

accommodate limited additional raw land development and redevelopment activities. The 

existing facilities have provided a limited additional capacity. 

GROWTH MANAGEMENT CONTROLS 

The Future Land Use element of the Monroe County comprehensive plan includes a goal (Goal 

101) providing that the County must manage growth in a way which enhances the quality of life, 

ensures safety, and protects valuable natural resources. One of the policies critical to achieving 

this goal is development and implementation of the Permit Allocation System which limits the 

number of permits the County may issue for new residential development. 

RATE OF GROWTH ORDINANCE 

The Rate of Growth Ordinance ("ROGO") limits the number of permits issued for new residential 

development in each ROGO area to 255 per year. The interim system limits the number of new 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-26 

residential developments in each ROGO area to the number of cesspits replaced within each 

ROGO area. If less than 255 cesspits are replaced in a year, then 255 permits for development 

cannot be issued. If more than 255 cesspits are replaced in a ROGO area within a year, the 

associated development permits cannot be issued until the following year. These provisions apply 

to the unincorporated areas of Monroe County. 

Allocation of permits is based not only on the number of cesspits eliminated but also on progress 

made on the Five Year Work Program. Each year the Administration Commission will review the 

County's progress on the program, and, if it determines substantial progress has not been made, 

the cap on new residential development will be reduced by at least 20% for the next year. 

Implementation of the interim system requires that FDEP, FDOH, FDCA, Monroe County 

coordinate their permitting procedures so that the state agencies do not issue wastewater 

disposal permits that allow development beyond the number of permits Monroe County may 

issue. The County may not issue development permits in excess of those that DEP or DOH may 

issue. 

4.7.2 New Pollutant Sources 

New pollutant sources can be expected with growth in the South-Central Keys Area. However, 

programs and management practices are already in place that will limit nutrient discharges to 

the Halo Zone WBIDS in the Florida Keys through minimum treatment standards and regulation 

of nutrient levels in new discharges. 

WASTEWATER MANAGEMENT RULES 

Current wastewater management programs will limit or preclude any significant increase in 

annual nutrient loading in the Halo Zone waters through the following provisions: 

 Elimination of Cess Pits and conventional septic tank systems through the Chapter 99-

395 requirements; 

 Requirement that all new and existing WWTPs with average daily flows (ADF) of 

100,000 GPD achieve BAT (10-10-10-1) standards and dispose of their finished in a 

shallow (at least 90 foot deep) Class V injection well pursuant to the Chapter 99-395 

requirements ; 

 Requirement that all new and existing WWTPs with average daily flows (ADF) of greater 

than 100,000 GPD achieve AWT (5-5-3-1) standards and dispose of their finished in a 

deep Class I injection well pursuant to the Chapter 99-395 requirements; 

 Requirements for submission of monthly discharge monitoring reports that will allow 

FDEP staff to identify and address non-complying WWTPs; and, 

 Authority for FDEP and FDOH to undertake enforcement actions for non-complying 

wastewater treatment practices. 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-27 

STORMWATER MANAGEMENT RULES 

Current stormwater management programs will limit any significant increase in annual nutrient 

loading in anthropogenic stormwater discharged to the Halo Zone waters through the 

following provisions: 

 Existing on-site stormwater management requirements of SFWMD related to new 

development activities; 

 Authority for FDEP and SFWMD to undertake enforcement actions for non-complying 

stormwater management practices; 

 Local Monroe County land development regulations governing the development of raw 

land and the redevelopment of properties that establish on-site stormwater attenuation 

and treatment requirements prior to discharge; 

 Ability of Monroe County to undertake authorized enforcement actions for noncomplying stormwater management practices; and 

 Navy rules and procedures which govern military uses of Boca Chica Airfield. 

OTHER RULES 

FDCA, through the designation of the Florida Keys as an Area of Critical State Concern, has 

additional authority to: 

 Require communities in the Florida Keys to modify their comprehensive plans to: 

 Protect shoreline and marine resources (including mangroves, coral reef 

formations, sea grass beds, fish and habitat 

 Limit the adverse impacts on the quality of water throughout the Florida Keys 

related to development activities; and 

 Protect existing and proposed major public investments related to public 

infrastructure; State parks, recreation facilities, aquatic preserves, and other 

publicly owned properties. 

 To limit the adverse impacts of public investments on the environmental resources of 

the Florida Keys. 

 To protect the public health, safety, and welfare of the citizens of the Florida Keys and 

maintain the Florida Keys as a unique Florida resource. 

To accomplish this responsibility, FDCA can compel local communities to modify their 

regulations to achieve these mandates, review all development orders issued by communities 

that are subject to these requirements, challenge development orders which are inconsistent 

with these requirements and impose development moratoriums. 

NOTE: Additional discussion of the underlying regulations and authority of agencies is 

summarized in more detail in Appendix A. 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-28 

4.8 CONFIRMED SOURCES OF FUNDING 

The Reasonable Assurance program for the South-Central Keys Area has an estimated 

aggregate cost of approximately $183.7 million. Dedicated funding for new management 

actions, as well as the ongoing operation and maintenance of already implemented 

management actions, will be essential for the expected reduction of nutrients in the Halo Zone 

waters. 

Funding is being provided by the individual stakeholders and State agencies, working 

individually and collectively where appropriate. No other funding sources are currently 

designated or committed to provide funds for completion of the wastewater and stormwater 

infrastructure in the South-Central Keys Area. Multiple sources of funding are confirmed for the 

reduction of nutrient loads entering the Halo Zone waters in the South-Central Keys Area. Table 

4-11 presents these commitments by participant and then summarizes the aggregate 

commitment in the South-Central Keys Area. 

Table 4-11 

Aggregate Funding Commitment 

For the South-Central Keys Area 

Stakeholder Implemented 

Funding 

Planned 

Funding 

Total Funding 

Commitment 

Monroe County $55,399,850 $128,277,000 $183,676,850 

United States Navy 

(Boca Chica Airfield) 

Undetermined 

Amount 

Undetermined 

Amount 

Undetermined 

Amount 

Florida Department of 

Transportation 

Ongoing 

Maintenance 

No Identified 

Joint Project 

Agreements 

Undetermined 

Amount 

Total Committed Funding for 

South-Central Keys Area $55,399,850* *128,277,000* $183,676,850* 

* Total amounts do not include U. S. Navy or FDOT funding. 

The largest investment to date has been made by the Monroe County in the Bay Point and 

South Lower Keys projects. 

4.9 IMPLEMENTATION SCHEDULE 

An integrated implementation schedule, previously summarized in Table 4-5, identifies specific 

management actions to be undertaken individually and collectively in the South-Central Keys 

Area by the participating stakeholders. The activities presented in that table are segmented in 

order to identify those management actions intended to achieve an interim milestone of 

measurable decreases in the concentrations of TN and TP by July 1, 2010 as well as 

subsequent management actions designed to assist in achieving the overall goal of this 

program by 2020. 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-29 

4.10 ENFORCEMENT PROGRAMS AND LOCAL ORDINANCES FOR 

NON-VOLUNTARY STRATEGIES 

Enforcement of existing ordinances by State, regional and local agencies will achieve the 

implementation of the wastewater and stormwater management actions included in the nonvoluntary strategies previously discussed in this section. Two types of enforcement programs 

cover the Florida Keys including: 

 Broad Scale Programs with general applicability to the South-Central Keys Area 

(summarized in Appendix A of this document) including: 

 Statewide Programs administered by FDCA, FDEP and FDOH which regulate 

land use, resource protection, wastewater and stormwater activities Statewide; 

and 

 Regional regulatory programs administered by SFWMD that focus on 

stormwater management and water quality issues, and which are applicable 

throughout South Florida. 

 Local Focus Programs which have been developed to meet the special needs of the 

Florida Keys and are applicable in the South-Central Keys Area (discussed in 

subsequent paragraphs of this subsection). 

Finally, the last portion of this subsection identifies specific responsibilities of State, regional and 

local agencies in enforcing non-voluntary strategies and management actions. 

4.10.1 Local Focus Regulatory Program Elements 

Recognizing the delicate nature and special needs of the Florida Keys, Florida has enacted 

legislation that focus on the specific needs of the Keys. These acts, intended to provide State 

agencies (FDCA, FDEP and FDOH) with special authority to manage and regulate those 

aspects of land use, wastewater treatment and effluent disposal practices to better protect local 

water quality the and fragile marine habitats of the Keys, include: 

 Areas of Critical State Concern Designation 

 Chapter 99-395 FS, Laws of Florida 

Both of these were previously discussed in Subsection 4-7. 

While the regulatory agencies mainly responsible for enforcement by Chapter 99-395 LF, local 

participants (eg. Monroe County and the cities) will enforce hook-ups and upgrades to 

applicable residential and non-residential wastewater sources. 

4.10.2 State Agency Enforcement Responsibilities 

Enforcement programs, as applied to this program, are primarily the responsibility of the FDEP 

and FDOH for wastewater management actions, and FDEP and SFWMD for Stormwater 

management actions. The FDCA also has a limited number of responsibilities for regional 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-30 

implementation of wastewater and stormwater management actions through its comprehensive 

planning responsibilities and its Areas of Critical State Concern designation for the Florida Keys. 

FDEP ENFORCEMENT RESPONSIBILITIES 

FDEP’s focus in the South-Central Keys Area for providing State enforcement and oversight 

activities to provide reasonable assurance for implementation non-voluntary wastewater 

management actions. 

Wastewater Activities

 Existing facilities in the Southern Central Keys Area are permitted by FDEP and have 

approved treatment and disposal systems 

 Boca Chica Airfield and its adjacent facilities is served by a central wastewater 

system, which will go through a planned upgrade to produce AWT effluent with 

disposal in a nominal 90-foot deep effluent disposal well in order to meet the 

higher wastewater treatment standards mandated by Chapter 99-395. 

 Monroe County has constructed central wastewater systems to serve the Bay 

Point area and the southern portion of the Lower Keys with AWT treatment and 

subsequent effluent with disposal in a nominal 90-foot deep. 

 

 Monroe County is designing and will begin construction in the near future of central 

wastewater systems to serve the Middle and northern sections of the Lower Keys and 

Lower Sugarloaf Key. These systems feature AWT treatment and subsequent effluent 

with disposal in a nominal 90-foot deep. 

 FDEP’s focus for this area of the keys is two-fold: 

 Review monthly DMRs to assure that the existing plants are operating in such a 

manner that they produce effluent that complies with the operating permits; 

 Assurance that the proposed new facilities will meet current State requirements 

(particularly Chapter 99-395 LF) by 

 Reviewing the design drawings to determine that the new facilities are 

capable of producing adequate treatment to achieve permit conditions, 

and subsequently issuing construction permits; 

 Inspecting these facilities during construction to ensure that they are built 

in compliance with their approved designed, and subsequently issuing 

operating permits. 

 Reviewing the each plant’s first year of monthly DMRs to assure that the 

existing plants are achieving the design effluent quality. 

Stormwater Activities

FDEP’s enforcement and oversight activities that will provide reasonable assurance of regional 

enforcement for achieving non-voluntary stormwater management actions basically focuses on 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-31 

Florida’s NPDES and TMDL programs as they relate to the improvement of the impaired Halo 

Zone waters: 

 FDEP also has provided strong guidance and support in the development of this RA 

plan, which indicates their support of the cooperative nature of the solutions to improve 

surface water quality in this region. 

 The City of Marathon’s stormwater management facilities are regulated under a 

Municipal Separate Storm Sewer System (MS4) Permit that contains sanctions and 

fines, as well as civil and criminal penalties, that can be used to compel compliance with 

permit requirements. 

FDOH ENFORCEMENT RESPONSIBILITIES 

FDOH’s enforcement and oversight activities that will provide reasonable assurance of regional 

enforcement for achieving non-voluntary wastewater management actions on the private facility 

level is anchored in the requirements and provisions of Chapter 99-395 Laws of Florida (LF) 

which requires FDOH to conduct enforcement actions against private owners of cesspits and 

non-complying septic tanks and OSTDS who have failed by July 1, 2010, to either: 

 Connect to a central wastewater system that complies with higher standards mandated 

by Chapter 99-395 LF; or 

 Upgrade their non-complying treatment practices to achieve Chapter 99-395 LF 

requirements. 

This requirement of State Law provides substantial authority and capability for reducing the 

discharge of nutrients from on-site wastewater treatment systems to the impaired Halo Zone 

waters from the any developed areas of the unincorporated area of Monroe County that are not 

being served by the County’s new central wastewater systems that have cesspits, septic tanks, 

and ATUs which will need to be eliminated/upgraded to achieve the mandated higher 

wastewater treatment standards. 

 Cesspit Elimination is mandated by Chapter 99-395 LF as part of the Keys-wide 

initiative to improve Halo Zone water quality. FDOH’s focus for this responsibility will 

include the following: 

 Initial Focus (prior to July 1, 2010): Verification that the existing substandard 

WWTPs are being upgraded to meet the Chapter 99-395 LF deadline; and 

 Subsequent Focus (after July 1, 2010): Routine regulatory oversight activities 

including timely review of the facility’s monthly DMRs to assure permit 

compliance and conducting enforcement actions if required to eliminate any noncompliance conditions. 

 Non-complying On-Site Systems require their owners to undertake one of the following 

actions to avoid violating Chapter 99-395 LF: 

 Initial Focus (prior to July 1, 2010): Verification that the existing substandard onsite systems have been eliminated or upgrade to meet the Chapter 99-395 LF 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 4.doc Page 4-32 

deadline, or commencement of enforcement activities to compel elimination or 

upgrading to achieve compliance; and 

 Subsequent Focus (after July 1, 2010): Routine regulatory oversight activities 

including timely review of the facility’s monthly DMRs to assure permit 

compliance and conducting enforcement actions if required to eliminate any noncompliance conditions. 

SFWMD ENFORCEMENT RESPONSIBILITIES 

SFWMD, through its Environmental Resource Permit program, provides key enforcement 

activities for new development and redevelopment activities in the Florida Keys that discharge 

stormwater to impaired halo zone waters. District enforcement and oversight activities that will 

provide reasonable assurance of regional enforcement for achieving non-voluntary 

management actions and strategies include: 

 Require construction permits and conduct inspection of construction activities which 

limits the short-term impacts during construction. 

 Require operating permits that focus on maximizing the treatment benefit of the 

stormwater facilities during the post-construction period. 

 Require field-verification the construction of permitted activities regulated through with 

Environmental Resource Permits by District enforcement staff. 

 Require oversight for the operations of permitted facilities to assure that facilities are 

achieving their target water quality concentrations in discharged flows (while operating 

permits are in effect) to assure that permit requirements are met and that the overall 

water quality goals of the facilities obtained. 

 Semi-annual helicopter and airplane aerial reconnaissance in some cases to identify 

activities that may not be visible during traditional land surveillance when it is 

determined that a potential violation exists to enable staff to conduct a site visit to 

determine the nature and extent of the possible violation and make determinations if 

additional enforcement is necessary. 

  
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 5.doc Page 5-1 

Section 5.0 

SCHEDULE TO ACHIEVE WATER QUALITY 

TARGETS

5.1 ACHIEVING WATER QUALITY TARGETS 

As defined previously, the nutrient concentrations in the Halo Zone and nearshore waters of 

the Florida Keys are dominated by farfield effects and anthropogenic sources of nutrients in 

the Keys incrementally add loads with increases in the Halo Zone concentrations that will be 

minimized through management actions (see Section 4). The target to be achieved is an 

insignificant increase to farfield (boundary) concentrations. Also, as the 1999 ambient 

nutrient concentrations average greater than those measured for the OFW designation and 

are expected to improve, the OFW ambient concentrations are expected to be restored. 

5.2 SCHEDULE TO ACHIEVE TARGETS 

The management actions to be completed by the signatories will be completed in 2020 for 

wastewater activities and stormwater activities. Based on modeling of the predicted impacts 

of the management actions superimposed on the farfield, the insignificant increase to the 

farfield concentration will be achieved soon after the management activities are completed. 

However, due to the nature of environmental processes, it is expected that the target 

conditions can be achieved in the Halo Zone waters for all of the Florida Keys by 2020. 
F K R A D

Florida Department of Environmental Protection 

KEYS REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 6.doc Page 6-1 

Section 6 

PROCEDURES FOR MONITORING 

AND REPORTING RESULTS

6.1 DESCRIPTION OF PROCEDURES FOR MONITORING AND 

REPORTING RESULTS 

Monitoring and reporting activities will provide the basis for establishing the water quality 

improvements that will be achieved through implementation of the proposed management 

actions. Monitoring, including both the sampling of water quality in the receiving waters and 

the oversight of management action implementation and operation, will provided the data 

and information required to assess improvements and compliance with the plan. Reporting 

activities will maintain a continuing flow of performance information that will support adaptive 

management efforts as may be required to achieve the anticipated benefits. 

6.1.1 Monitoring Networks 

A number of monitoring networks that have been designed and implemented to document 

the effectiveness of the various management actions, demonstrate reasonable progress in 

the South-Central Area watersheds, and provide quantifiable results for the annual progress 

report (submitted to the FDEP) associated with this plan. Examination of STORET identified 

3,744 stations in the general Florida Keys that collect beach, canal, estuary, operating 

facility, lake, ocean, river/stream, stormwater and well samples for a broad range of 

investigational and regulatory purposes. 

These water quality monitoring networks are operated by a combination of stakeholders, 

interested parties, agencies. Many of these stations are associated with the Florida Keys 

National Marine Sanctuary’s ongoing monitoring programs focused on long-term water 

quality and seagrass studies. 

 The primary network of interest for the South-Central Area is the FKNMS Water 

Quality Monitoring Program network, operated by FIU’s SERC. The westernmost 

portion of this network includes a number of “local” stations that have 10 years of 

quarterly data. These stations can be used to define long-term nutrient 

concentration trends in the waters that are most immediate to the WBIDs of interest 

including the Halo Zone and the more immediate nearshore waters. 

 Other stations, including the westernmost Florida Bay network stations, provide 

useful information on the more distant nearshore and marine waters outside of the 

immediate area of interest. 

Figure 6-1 presents a map indicating the location of the 17 FKNMS monitoring stations 

located within the South-Central Area and identifies the boundaries of WBID 6014C, 6013A, 

6013B, 6013C, 6013D, 6012A, 6012B, 6012C, 6012D, and 6018. 

F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 6.doc Page 6-2 

6.1.2 Procedures for Monitoring and Reporting Results 

Procedures to be used in the South-Central Area for monitoring implementation progress 

and water quality improvements must focus on the elimination of substandard wastewater 

treatment practices (pursuant to Chapter 99-395, LF) and corresponding changes in 

ambient water quality in the canals, halo zone and nearshore waters. 

MONITORING PROCEDURES 

The monitoring program for the South-Central Area primarily requires the efforts of the 

central wastewaters system operators and the operator of the operators of the existing 

FKNMS and Florida Bay ambient water quality monitoring networks. 

The monitoring program, which starts upon EPA’s approval of the South-Central Area RAD, 

focuses upon immediate measurement of the benefits being produced by implementation of 

the proposed management activities: 

1. Total Wastewater Service Level which is the basic measure of net nutrient 

reductions being achieved in the South-Central Area. Specific measures of 

progress include: 

A. Total number of physical connections to the central wastewater system; 

B. Total number of cess pit EDUs eliminated by connection; 

C. Total number of substandard septic tank system EDUs eliminated by 

connection; 

D. Total number of sub-BAT/BAT treatment facilities eliminated by connection; 

E. Total number of sub-BAT/BAT treatment facilities upgraded; 

F. Total number of connected EDUs; and 

G. Total pounds of nutrients in the finished effluent that is discharged to shallow 

disposal wells. 

Measurement of the total number of physical connections and eliminated cess pits, 

septic tanks and sub-BAT/BAT facilities will be tracked as part of the ongoing 

records of the central wastewater treatment system. Quarterly nutrient loads 

discharged in the finished effluent to shallow disposal wells will be calculated from 

the monthly Discharge Monitoring Reports (DMRs) routinely submitted to FDEP as 

part of ongoing operations. Nutrients discharged to deep disposal wells will be not 

be tracked as they are not expected to be measurable due to the depth at which 

they are being discharged. 

2. Ambient Bubble WBID Water Quality Trends, measured in the halo zone WBID 

waters and the more immediate nearshore waters (at distances up to 5,600 meters 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 6.doc Page 6-3 

off the shoreline), which demonstrate localized water quality improvement in the 

“backyard” of the Florida Keys. Specific measures of progress include: 

A. Quarterly measurement of Total Nitrogen and Total Phosphorus 

concentrations at the existing stations in the existing FKNMS and Florida 

Bay monitoring networks (currently operated by FIU/SERC) that are 

generally located inside of the halo zone WBIDs at distances up to 5,600 

meters off the shoreline. This includes 9 existing FKNMS stations adjacent 

to the Service Area. 

These open water stations are considered most important in the monitoring program 

due to their location in the “backyard waters” of the Florida Keys and their intimate 

and immediate interaction with the anthropogenic loads being discharged by the 

South-Central Area. 

3. Nearshore Water Quality Trends, measured in the existing FKNMS and Florida Bay 

nearshore waters monitoring stations located outside of the halo zone WBIDs (at 

distances greater than 5,600 meters off the shoreline), which generally indicate the 

water quality changes in the marine environment outside the general impact of Keys 

discharges that are attributable to changing farfield loadings. Specific measures of 

progress include: 

A. Quarterly measurement of Total Nitrogen and Total Phosphorus 

concentrations at the existing stations in the existing FKNMS and Florida 

Bay monitoring networks (currently operated by FIU/SERC) that are 

generally located outside of the halo zone WBIDs at distances greater than 

5,600 meters off the shoreline. This includes 8 FKNMS and 1 SFCWQ 

stations in the proximity of the Service Area. 

MONITORING OF VIOLATIONS AND EXCEPTIONS

A significant and parallel element of the monitoring program, which is currently in 

place irrespective of the receipt of EPA’s approval of the South-Central Area RAD, is 

the monitoring of violations and exceptions. FDEP currently reviews DMR for all 

permitted wastewater treatment facilities in the Florida Keys to check for violations 

of permitted flow rates and discharge concentration limits, as well as exceptions 

which typically include instances where the operator of a permitted facility fails to 

submit their DMR in a timely manner. 

Both of these monitoring activities provide additional assurance that facilities, once 

implemented, are properly operated so as not to exceed their permit limits and to 

ultimately achieve their planned nutrient load reductions. 

REPORTING PROCEDURES 

The following procedures and timing will be utilized to accomplish timely reporting of 

monitoring results in the South-Central Area: 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 6.doc Page 6-4 

1. Quarterly compilation of the total number of physical system connections 

and eliminated cess pits, septic tanks and sub-BAT/BAT facilities will be 

tracked as part of the ongoing records of the central wastewater treatment 

system. 

2. Nutrient loads discharged in the finished effluent to shallow disposal wells 

will be calculated on a quarterly basis using the flow and nutrient 

concentration values documented in the monthly Discharge Monitoring 

Reports (DMRs) routinely submitted to FDEP as part of ongoing wastewater 

facility operations. 

3. Values for each of the metrics will be reported to FKNMS Steering 

Committee on a quarterly basis by each central wastewater system. 

4. Annually halo zone and nearshore waters nutrient concentration results will 

be summarized by EPA or, alternately, their contractor (currently FIU/SERC) 

and reported to FKNMS Steering Committee. 

6.2 QUALITY ASSURANCE/QUALITY CONTROL ELEMENTS 

Quality assurance and quality control are important to the success of monitoring activities as 

they provide assurances that the data was collected using proper techniques to assure that 

it is representative and reliable. 

 A Quality Assurance (QA) Plan is the planning process to confirm that a process is 

properly completed and checked to achieve a valid result. 

 Quality Control is the actual process of implementing the QA plan. 

 Quality Management (QM) refers to both and is necessary, especially for monitoring 

programs, to ensure that the inferences made from the results are scientifically 

justified and valid. 

Spurious results oftentimes occur in monitoring programs due to improperly sampling 

ambient waters, poorly storing and transporting the samples, extended storage of the 

sample beyond proper holding times, and contaminated laboratory procedures, to name a 

few. For the FKRAD, ambient sampling and biological assessments will be done under 

contract to the State or EPA. 

 State contracted monitoring will be conducted pursuant to FDEP’s Quality 

Assurance Rule (Chapter 62-160, FAC). 

 Federal monitoring is accomplished via the Florida Keys National Marine Sanctuary 

monitoring programs under the United States Environmental Protection Agency and 

National Oceanic and Atmospheric Administration (NOAA). 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 6.doc Page 6-5 

Monitoring is implemented through studies by the Florida Marine Research Institute (FMRI) 

and the Florida International University (FIU) via the Water Quality Protection Program 

(WQPP) and is governed by Federal quality management requirements. 

ELEMENTS THAT DEMONSTRATE MONITORING AND LABORATORY 

ANALYSIS ACTIVITIES WILL COMPLY WITH CHAPTER 62-160, F.A.C. 

Laboratories conducting field data collection and/or laboratory analyses in conjunction with 

this RAD program will comply with the following quality assurance protocols: 

State Agencies programs involved in monitoring activities as part of this RAD 

program will comply with the following rules and/or have the following documents: 

 Current State-approved Quality Assurance Plan on file that complies with 

FDEP's Quality Assurance rule, Chapter 62-160 F.A.C.; 

 Analyzing laboratory will be NELAC certified; and 

 FDEP approved Standard Operating Procedures will be used as required. 

Federal Agencies, including USEPA , DOD and their Contractors, conducting field 

monitoring and laboratory activities as part of this RAD program, will comply with 

USEPA quality assurance protocols. 

6.3 PROCEDURES FOR ENTERING ALL APPROPRIATE DATA 

INTO FL-STORET 

Agencies involved in entering all appropriate data into FL-STORET include the following: 

 The FIU/SERC will upload all surface water quality data for the monitoring networks 

to the EPA National STORET Database. 

 The FDEP Tallahassee STORET section also receives a copy of these uploads. The 

District currently has a contractor developing programming methodologies using 

ADaPT / EDMS formatting, which will allow STORET uploads to occur directly from 

the District laboratory LIMS system. Ground water quality data will also accompany 

the STORET uploads when the new data-flow convention is completed. 

6.4 RESPONSIBLE MONITORING AND REPORTING ENTITY 

The stakeholders, interested parties and contractors previously described in Subsection 

5.1.2 are responsible for the collection of water quality data for their respective monitoring 

programs. All data collected for the management actions and projects listed in Section 4 will 

be utilized for reporting the status and progress of the South-Central Area program. 

FIU/SERC will be responsible for compiling the water quality monitoring data on an annual 

basis. All data collected for the monitoring networks will be checked for quality assurance 

and reviewed internally on either a monthly or quarterly basis. 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 6.doc Page 6-6 

6.5 FREQUENCY AND REPORTING FORMAT FOR REPORTING 

MONITORING RESULTS 

Reporting will be submitted in written or digital form in any of customary and/or contractual 

formats including reports, spreadsheets, databases, GIS coverages and other graphical 

formats. Frequency of reporting results by monitoring network/management activity is 

summarized in the following table: 

Table 6-1 

Monitoring Network Reporting Frequencies 

Monitoring Networks Operator Reporting 

Frequency 

FKNMS Ambient Water Quality Network Florida Keys National 

Marine Sanctuary Annually 

Florida Bay Ambient Water Quality Network FIU/SERC Annually 

6.6 FREQUENCY AND REPORTING FORMAT FOR 

IMPLEMENTATION OF PROPOSED MANAGEMENT 

ACTIVITIES 

The individual stakeholders will report on the implementation of management activities 

through an annual summary report generated each January. FDEP will update stakeholders 

on the progress and results of the collective monitoring networks at periodic stakeholder 

group meetings. 

6.7 METHODS FOR EVALUATING PROGRESS TOWARDS GOALS 

FDEP will use water quality data results from the networks previously described, as 

available and appropriate, to evaluate the progress of the implemented management 

actions toward meeting water quality management goals. Aggregated data will be 

interpreted using graphical and statistical methodologies. 

  
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL KEYS AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 7.doc Page 7-1 

Section 7 

PROPOSED CORRECTIVE ACTIONS

7.1 CORRECTIVE ACTIONS FOR NON-IMPROVEMENT OF 

WATER QUALITY 

It is anticipated that corrective actions will not be necessary as applied to the water quality 

impairment associated with the South-Central Area watersheds. Unlike many other areas of 

Florida that have been identified as impaired under the IWR, the causes of the impairment 

in this area originate from three known sources: 

 Wastewater 

 Anthropogenic Stormwater 

 Farfield Effects 

The management actions previously described in Section 4 are largely focused on the 

elimination or reduction of the local anthropogenic sources (primarily wastewater 

discharges) associated with existing human population in the Florida Keys. Therefore, 

direct improvement to the groundwater based nutrient discharges to local receiving waters 

(canals and the Halo Zone surface waters), can be reasonably predicted to occur. 

In addition, the communities support the management actions that have been implemented 

and/or proposed due to the anticipated improvement in water quality, the marine 

environment and aesthetics which directly relate to their quality of life. These changes are 

also expected to directly benefit the local and regional tourist driven economies. 

7.2 CORRECTIVE ACTIONS FOR SCHEDULE NON-ATTAINMENT 

OF MANAGEMENT ACTIONS 

Reducing water quality impairments in the Florida Keys, due to the fragile nature of the 

nearshore waters and the numerous pollutant sources that act upon them, will require a 

concerted National, Regional and local effort for many years to come. 

 The potential exists that the management actions implemented currently and 

proposed for implementation through summer of 2010 and subsequently over the 

next ten years will not correct locally-originated nutrient based water quality 

impairments in the Halo Zone waters as quickly as proposed (stated goal of no 

impairment by 2020). 

 It is apparent that the cumulative effects of anthropogenic effects originating in the 

Gulf region and portions of peninsular Florida documented in terms of the ambient 

nutrient concentrations of the marine waters surrounding and circulating through the 

Florida Keys, will not likely be solved in the next few decades. 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 7.do Page 7-2 

 It is sheer folly to believe that Man will be able to control or ameliorate the larger 

farfield effects of Nature such as deep ocean upwelling, African dust or global 

warming in the near future. 

Of these concerns, the Keys communities can only work towards reducing the nutrient loads 

generated by anthropogenic activities occurring on the islands of the Florida Keys. They 

have no ability to control or reduce nutrient sources occurring naturally in the Keys or 

originating outside their local area. 

CORRECTIVE ACTIONS 

The provisions of Chapter 99-395 LF provide the basis for any corrective actions that may 

be required for schedule non-attainment of management actions. More specifically, this law 

requires: 

 FDOH to conduct enforcement actions against owners cess pits to eliminate their 

cess pits and either: 

 Connect to a central wastewater system that meets the Chapter 99-395 LF 

standards; or 

 Secure a permit, install an acceptable OSTDS, and thereafter operate and 

maintain the OSTDS in such a manner that it complies with the requirements 

of Chapter 99-395 LF. 

 FDOH to conduct enforcement actions against owners of non-complying OSTDSs 

as required have them: 

 Connect to a central wastewater system that meets the Chapter 99-395 LF 

standards; 

 Upgrade/repair their existing OSTD to meet the Chapter 99-395 LF 

standards, and thereafter operate and maintain their OSTDS in such a 

manner that it complies with the requirements of Chapter 99-395 LF; or 

 Secure a permit, install an acceptable new OSTDS, and thereafter operate 

and maintain the OSTDS in such a manner that it complies with the 

requirements of Chapter 99-395 LF. 

 FDEP to conduct enforcement actions against public and privately owned WWTPs 

that do not produce an effluent and/or dispose of its effluent in a manner compliant 

with the requirements of Chapter 99-395 LF, in order to have them: 

 Connect to a central wastewater system that meets the Chapter 99-395 LF 

standards; or 

 Upgrade their existing WWTP to meet the Chapter 99-395 LF standards, 

and thereafter operate and maintain their WWTP in such a manner that it 

complies with the requirements of Chapter 99-395 LF. 
F K R A D

Florida Department of Environmental Protection 

REASONABLE ASSURANCE DOCUMENTATION 

SOUTH-CENTRAL AREA 

December 2008 

S:\FDEP\South-Central Keys RAD\FKRAD SC Section 7.do Page 7-3 

7.3 FDEP NOTIFICATION PROCESS FOR CORRECTIVE ACTION 

IMPLEMENTATION 

FDEP is an active member in the South-Central Area Watershed Management Plan 

Stakeholders group and will be aware of all actions of the group, including the status of the 

implementation of corrective management actions. 

The annual report will be the formal mechanism for reporting the progress of various 

management actions, the overall success of the plan, and the need for corrective actions. 

This annual report will be transmitted to the FDEP – Tallahassee as well as the local 

Marathon and South Florida District offices. 

 Corrective actions that are implemented will be documented in the annual report as 

a separate category to ensure the FDEP is provided sufficient information on the 

plans implementation and success. 

 If a corrective action is deemed overly significant, such as the introduction of a new 

management action to address the failure of an existing management action, the 

FDEP will be notified formally through written correspondence of this significant 

change to the plans implementation. In addition, this plan will be updated and 

resubmitted to the FDEP-Tallahassee and the local FDEP offices to address the 

proposed changes. 

  
F K R A D

Florida Department of Environmental Protection 

FLORIDA KEYS REASONABLE ASSURANCE DOCUMENTATION 

December 2008 

S:\FDEP\South-Central Keys RAD\List of Acronyms.doc LAA-1 

LIST OF ABBREVIATIONS AND ACRONYMS

ac-ft Acre-feet 

ACSC Area of Critical State Concern 

Al Aluminum 

Alk Alkalinity 

AMC Annual Mean Concentration 

As Arsenic 

ATT Advanced Treatment Technology 

AWT Advanced Wastewater Treatment 

BAPRT Best Available Phosphorus Reduction Technology 

BAT Best Available Technology 

BMAP Basin Management Action Plan 

BMP Best Management Practice 

BOD5 Five-Day Biochemical Oxygen Demand 

BST Bacterial Source Tracking 

CaCO3 Calcium Carbonate 

Cd Cadmium 

CDM Camp Dresser & McKee, Inc 

CERP Comprehensive Everglades Restoration Plan 

Chl-A Chlorophyll – A 

CIP Capital Improvement Program 

cm Centimeter 

cm/day Centimeters Per Day 

COD Chemical Oxygen Demand 

Cond Conductivity 

CPP Continuing Planning Process 

Cr Chromium 

CREP USDA Conservation Reserve Enhancement Program 

Cu Copper 

CWA Clean Water Act 

DCIA Directly Connected Impervious Area 

DIN Dissolved Inorganic Nitrogen 

Diss- DissolvedDO Dissolved Oxygen 

DOQQ Digital Orthographic Quartersection Quadrangle 
F K R A D

Florida Department of Environmental Protection 

FLORIDA KEYS REASONABLE ASSURANCE DOCUMENTATION 

December 2008 

S:\FDEP\South-Central Keys RAD\List of Acronyms.doc LAA-2 

EDU Equivalent Dwelling Unit 

EMC Event Mean Concentration 

EMS Emergency Management Services 

ENP Everglades National Park 

ERU Equivalent Residential Unit 

ESC Erosion and Sediment Control 

F.A.C. Florida Administrative Code 

F.S. Florida Statutes 

FAC Florida Administrative Code 

FAW Florida Administrative Weekly 

FC Fecal Coliform Bacteria 

FDACS Florida Department of Agriculture and Consumer Services 

FDCA Florida Department of Community Affairs 

FDEP Florida Department of Environmental Protection 

FDOH Florida Department of Health 

FDOR Florida Department of Revenue 

FDOT Florida Department of Transportation 

FIU Florida International University 

FKAA Florida Keys Aqueduct Authority 

FKNMS Florida Keys National Marine Sanctuary 

FKRAD Florida Keys Reasonable Assurance Documentation 

FS Fecal Streptococcus Bacteria 

FY Fiscal Year 

g/m2/yr grams per square meter per year 

GIS Geographic Information System 

GWLF Generalized Watershed Loading Functions 

ha Hectare 

Hg Mercury 

HLR Hydraulic Loading Rate 

HSG Hydric Soil Group 

HSPF Hydrologic Simulation Programs in FORTRAN 

HUC Hydrologic Unit Code 

IP Implementation Plan 

IWR Impaired Waters Rule 

kac-ft Thousand acre-feet 

kg Kilograms 

KLWTD Key Largo Wastewater Treatment District 
F K R A D

Florida Department of Environmental Protection 

FLORIDA KEYS REASONABLE ASSURANCE DOCUMENTATION 

December 2008 

S:\FDEP\South-Central Keys RAD\List of Acronyms.doc LAA-3 

km Kilometer 

LA Load Allocation 

LF Laws of Florida 

LIMS Laboratory Information Management System 

LUC Land Use Characterization 

MFR Multi-Family Residential 

μg/l Micrograms per Liter 

mg/l Milligram Per Liter 

mg/L Milligrams Per Liter 

MLUS Mixed Land Use Site 

MS4 Municipal Separate Storm Sewer System 

mt Metric ton 

NAD88 North American Datum of 1988 

NAPP National Aerial Photography Program 

NAWQA National Atmospheric Water Quality Assessment 

NCDC National Climactic Data Center 

NGVD National Geodetic Vertical Datum 

NH4 Ammonia 

Ni Nickel 

NO2 Nitrite 

NO3 Nitrate 

NOx Nitrite + Nitrate 

NOAA National Oceanic and Atmospheric Administration 

NPDES National Pollutant Discharge Elimination System 

NPS Nonpoint source 

NRCS Natural Resources Conservation Service 

NTU Nephelometric Turbidity Unit 

NURP Nationwide Urban Runoff Program 

O&G Oil and Grease 

O&M Operation and Maintenance 

OFW Outstanding Florida Water 

OP Ortho-Phosphorus 

OSTDS On-Site Treatment and Disposal System 

P Phosphorus 

Pb Lead 

PCU Platinum cobalt unit 

Pest Pesticide 
F K R A D

Florida Department of Environmental Protection 

FLORIDA KEYS REASONABLE ASSURANCE DOCUMENTATION 

December 2008 

S:\FDEP\South-Central Keys RAD\List of Acronyms.doc LAA-4 

pH Logarithm of the Reciprocal of the Hydrogen Ion Concentration 

PLR Phosphorus Loading Rate 

PLRG Pollution Load Reduction Goals 

Ppb Parts per Billion 

PPM Pollution Prevention Measure 

PS Point Source 

PY Permit Year 

QA Quality Assurance 

QAP Quality Assurance Plan 

QBEL Quality-Based Effluent Limitation 

QC Quality Control 

QM Quality Management 

RAD Reasonable Assurance Documentation 

RPD Relative Percent Difference 

SAV Submerged Aquatic Vegetation 

SERC Southeast Environmental Research Center 

SFR Single Family Residential 

SFUE Single Family Unit Equivalent 

SFWMD South Florida Water Management District 

SOD Sediment Oxygen Demand 

SPPM Stormwater Pollutant Prediction Modeling 

SSAC Site Specific Alternative Criteria 

SWAMP Surface Water Assessment and Monitoring 

SWAP Source Water Assessment Program 

SWCD Soil and Water Conservation District 

SWIM Surface Water Improvement and Management 

SWM Stormwater Management 

SWMM Storm Water Management Model 

SWQ Stormwater Quality 

SWU Stormwater Utility 

TBEL Technology-Based Effluent Limitation 

TC Total Coliform Bacteria 

Temp Temperature 

TF Fecal Coliform Bacteria 

TKN Total Kjeldahl Nitrogen 

TMDL Total Maximum Daily Load 

TN Total Nitrogen 
F K R A D

Florida Department of Environmental Protection 

FLORIDA KEYS REASONABLE ASSURANCE DOCUMENTATION 

December 2008 

S:\FDEP\South-Central Keys RAD\List of Acronyms.doc LAA-5 

TP Total Phosphorus 

TS Total Solids 

TSI Trophic State Index 

TSS Total Suspended Solids 

Turb Turbidity 

TWG Technical Working Group 

UAA Use Attainability Analysis 

URS URS Corporation 

USACE U.S. Army Corps of Engineers 

USDA United States Department of Agriculture 

USEPA United States Environmental Protection Agency 

USGS U.S. Geological Survey 

USLE Universal Soil Loss Equation 

VS Volatile Solids 

VSS Volatile Suspended Solids 

WBID Waterbody identification number 

WCA Water Conservation Area 

WLA Waste Load Allocation 

WMP Watershed Management Plan 

WQ Water Quality 

WQIP Water Quality Improvement Plan 

WQMP Water Quality Management Plan 

WQPP Water Quality Protection Program 

WS Watershed 

WSPP Watershed Protection Plan 

WWTP Wastewater Treatment Plant 

WY Water year 

Zn Zinc 
EXHIBITS