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 EN VIRONMENTAL 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 33607F K R A D Florida Department of Environmental Protection REASONABLE ASSURANCE DOCUMENTATION SOUTH-CENTRAL KEYS AREA December 2008

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## 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

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## 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

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## 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 4-24F K R A D Florida Department of Environmental Protection REASONABLE ASSURANCE DOCUMENTATION SOUTH-CENTRAL KEYS AREA December 2008

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### 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 MONI TORING 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 DOCU MENT (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

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## 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 .................................................... 6-6F K R A D Florida Department of Environmental Protection REASONABLE ASSURANCE DOCUMENTATION SOUTH-CENTRAL KEYS AREA December 2008

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## 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 ............ 6-1F K R A D Florida Department of Environmental Protection REASONABLE ASSURANCE DOCUMENTATION SOUTH-CENTRAL KEYS AREA December 2008

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## Technical Information Document (Separate Volume) A. Governing Regulations B. Water Quality C. Living Resources
D. Models and Simulations E. Public Involvement Program F. References/BibliographyF K R A D Florida Department of Environmental Protection REASONABLE ASSURANCE DOCUMENTATION SOUTH-CENTRAL KEYS AREA December 2008

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# E XECUTIVE 

# S UMMARY

In accordance with Section 62-303.600 FAC, th is 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 approx imately 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, accordi ng 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 pr actices (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 drainf ield 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 degreeF 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, Missi ssippi 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 ZoneF 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%

NutrientModel Natural Conditions Concentration (μg/l) 1999 Baseline Concentration @ 500 meters (μg /l) Concentration After Management Actions @ 500 meters (μg /l) Water Quality Target ( μ g /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 7F 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 havebeen 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 theF 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 MA NAGEMENT 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 fa cility 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 fa cility 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 2010F 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 fa cility 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 fa cility 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 fa cility 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

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# Section 1.0 

# B ACKGROUND

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 D epartment can document there is reasonable assurance that the impairment will be effectiv ely 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 Departm ent decides to not list an impaired water segment for a given pollutant. This document ation 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 (incl uding state and local government) will prepare the necessary documentation to demonstrate reasonable assurance that their proposed control mechanisms will restore a given wate r 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 onF 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 implementat ion 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 approx imately 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 (BMP s). Also, the BMPs can generally be Figure 1-1 Florida Ke y sF 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 drainf ield 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 historica lly 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 AreaF 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 r epresentative 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 reasonabl e 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 Assuranc e 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 Na tional 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


# I DENTIFICATION OF 

# T HE 

# I MPAIRED 

# W ATERS

2.1 UNDERSTANDING OF IMPAIR MENT 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 Maintenanc e 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 s ources 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 Na tional 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, salinit y, 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 Ou tstanding 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 atte mpt 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 impac ts of farfield sources in the Bubble WBIDs and nearshore waters of the Florida Keys. Farfi eld sources include outfl ow 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 propertiesF 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 usi ng 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 th is 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 

# D ESCRIPTION OF 

# W ATER 

# Q UALITY 

# T ARGETS

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 μ g/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 Targ ets 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 reproducti on and mortality. Inadequate methods for determining conch age, variable fe cundities, 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 pullingnutrients 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 comm unities 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 ac tivities for touris ts 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 speciesF 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 quant itative 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 conditi on 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 r easonable 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 ( μ g/l) Water Quality Target Concentration @ 500 meters ( μ g/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 7F 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 Standard s 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 9F 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 condi tion 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 diffe rent 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 Ev erglades, 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 

# D ESCRIPTION OF 

# P ROPOSED 

# M ANAGEMENT 

# A CTIONS 

# T O 

# B E 

# U NDERTAKEN

4.1 NAMES OF THE RESPONSIBL E 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 Represent ative, 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 incrementa lly 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 di scharged 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 managemen t 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)

I MPLEMENTED /O PERATIONAL M ANAGEMENT A CTIONS

 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%

P LANNED F UTURE M ANAGEMENT A CTIONS

 Elimination of Cesspits* 439 3.8%

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

 Elimination of Privat e 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 Fo rmal 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 INDIVI DUAL 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 collectivel y achieve a significant reduction of nutrient discharges to the halo zone waters. Baseline nutrient loading, reductions attributable toF 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 discu ssed 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 Pro posed 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 ofF 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 info rmation 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 MA NAGEMENT 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 fa cility 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 fa cility 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 2010F 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 fa cility 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 fa cility 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 fa cility 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 t he 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 ( μ g /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 7F 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
2010F 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
2010F 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 2010F 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 2010F 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 2010F 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 2010F 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 c ould 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 Flor ida Keys Carrying Capacity Study (FKCCS).

The residential canals that were previously model ed 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 ort hographic 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 t able [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 theF 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 LocationsF 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 ModelF 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 attr ibutable to identified management actions. Changes in Canal 50 are summarized as an ex ample 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 approximately1,600 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 μ g/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, approximat ely 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 μ g/l 130 μ g/l -70 μ g/l 35% End of Branch A 340 μ g/l 160 μ g/l -180 μ g/l 53% End of Branch B 280 μ g/l 170 μ g/l -110 μ g/l 39% End of Branch C 420 μ g/l 180 μ g/l -240 μ g/l 57% End of Main Branch 480 μ g/l 220 μ g/l -260 μ g/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 levelsF 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 μ g/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, approximat ely 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 μ g/l 8 μ g/l -20 μ g/l 83% End of Branch A 68 μ g/l 10 μ g/l -58 μ g/l 85% End of Branch B 44 μ g/l 14 μ g/l -30 μ g/l 68% End of Branch C 86 μ g/l 16 μ g/l -70 μ g/l 81% End of Main Branch 99 μ g/l 22 μ g/l -77 μ g/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 c anal 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 or thographic 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 bei ng “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 redevel opment 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 resour ces. 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 t he number of permits issued for new residential development in each ROGO area to 255 per year. The interim system limits the number of newF 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 Progr am. Each year the Administra tion 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 thr ough 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, challe nge development orders which are inconsistent with these requirements and impose development moratoriums. NOTE: Additional discussion of the underlyin g 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 millio n. Dedicated funding for new management actions, as well as the ongoing operation and maintenance of already implemented management actions, will be essential for the ex pected 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 ORDI NANCES FOR NON-VOLUNTARY STRATEGIES

Enforcement of existing ordinances by State, regional and local agencies will achieve theimplementation of the wastewater and stormwater management actions included in the nonvoluntary strategies previously discussed in th is 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 devel oped 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 identif ies specific responsibilitie s 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 spec ial 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 limit ed number of responsibilities for regionalF 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-vo luntary stormwater management actions basically focuses onF 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 rela te 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 c ooperative 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 t hat 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 ac tions 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 subs tantial 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 acti ons 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 LFF 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 acti ons 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 

# S CHEDULE 

# T O 

# A CHIEVE 

# W ATER 

# Q UALITY TARGETS

5.1 ACHIEVING WATER QUALITY TARGETS

As defined previously, the nutri ent concentrations in the Halo Zone and nearshore waters of the Florida Keys are dominated by farfield effects and anthropogenic sour ces 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 afte r 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 

# P ROCEDURES FOR 

# M ONITORING AND 

# R EPORTING 

# R ESULTS

6.1 DESCRIPTION OF PROCED URES FOR MONITORING AND REPORTING RESULTS

Monitoring and reporting activities will provide the basis for establishing the water quality improvements that will be achieved thr ough implementation of the proposed management actions. Monitoring, including both the sampling of water quality in the receiving waters and the oversight of management action implement ation and operation, will provided the data and information required to assess improvement s 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 th is 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 t he 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 st arts 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 finis hed effluent that is discharged to shallow disposal wells.

Measurement of the total number of physi cal 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 metersF 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 envir onment 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.

M ONITORING OF V IOLATIONS AND E XCEPTIONS
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, t heir contractor (currently FIU/SERC) and reported to FKNMS Steering Committee.


## 6.2 QUALITY ASSURANCE/QUALI TY 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 m onitoring 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 REPORTIN G 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 R EPORTING 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


# P ROPOSED 

# C ORRECTIVE 

# A CTIONS

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 m anagement 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 Flor ida 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 PROC ESS FOR CORREC TIVE 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 w ill 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 

# L IST OF 

# A BBREVIATIONS AND 

# A CRONYMS

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 BOD 5 Five-Day Biochemical Oxygen Demand BST Bacterial Source Tracking CaCO 3 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 QuadrangleF 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 Agri culture 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 DistrictF 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
NH 4 Ammonia
Ni Nickel NO 2 Nitrite NO 3 Nitrate NO x 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 PesticideF 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 NitrogenF 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