FLORIDA DEPARTMENT OF ENVIRONMENTAL PROTECTION 

Division of Water Resource Management, Bureau of Watershed Management

NORTHEAST DISTRICT • UPPER EAST COAST BASIN 

Final TMDL Report 

Dissolved Oxygen and Nutrient 

TMDL for 

Spruce Creek, 

WBID 2674A 

Wayne Magley, Ph.D., P.E. 

April 2008 
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Acknowledgments 

Editorial assistance provided by: Jan Mandrup-Poulsen and Linda Lord. 

Geographic information assistance (GIS) provided by: Janis Paulsen and Latrincy 

Whitehurst. 

For additional information on the watershed management approach and impaired waters 

in the Upper East Coast Basin, contact: 

Jennifer Gihring 

Florida Department of Environmental Protection 

Bureau of Watershed Management 

Watershed Planning and Coordination Section 

2600 Blair Stone Road, Mail Station 3565 

Tallahassee, FL 32399-2400 

Email: jennifer.gihring@dep.state.fl.us

Phone: (850) 245–8418 

Fax: (850) 245–8434 

Access to all data used in the development of this report can be obtained by contacting: 

Wayne Magley 

Florida Department of Environmental Protection 

Bureau of Watershed Management 

Watershed Assessment Section 

2600 Blair Stone Road, Mail Station 3555 

Tallahassee, FL 32399-2400 

Email: wayne.magley@dep.state.fl.us

Phone: (850) 245–8463 

Fax: (850) 245–8444 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Contents 

Chapter 1: INTRODUCTION___________________________________1

1.1 Purpose of Report ______________________________________________1

1.2 Identification of Waterbody_______________________________________1

1.3 Background ___________________________________________________5

Chapter 2: DESCRIPTION OF WATER QUALITY PROBLEM ________6

2.1 Statutory Requirements and Rulemaking History ____________________6

2.2 Information on Verified Impairment ________________________________6

Chapter 3. DESCRIPTION OF APPLICABLE WATER QUALITY 

STANDARDS AND TARGETS _______________________9

3.1 Classification of the Waterbody and Criteria Applicable to the TMDL ____9

3.2 Applicable Water Quality Standards and Numeric Water Quality 

Target_________________________________________________________9

3.2.1 Dissolved Oxygen Criterion __________________________________9

Chapter 4: ASSESSMENT OF SOURCES_______________________11

4.1 Types of Sources ______________________________________________11

4.2 Potential Sources of Nutrients in the Spruce Creek Watershed ________11

4.2.1 Point Sources _____________________________________________11

4.2.2 Land Uses and Nonpoint Sources _____________________________13

4.3 Source Summary ______________________________________________22

4.3.1 Summary of Nutrient Loadings to Spruce Creek from Various 

Sources __________________________________________________22

Chapter 5: DETERMINATION OF ASSIMILATIVE CAPACITY_______25

5.1 Determination of Loading Capacity________________________________25

5.1.1 Data Used in the Determination of the TMDL_____________________26

5.1.2 TMDL Development Process _________________________________32

5.1.3 Critical Conditions/Seasonality ________________________________39

Chapter 6: DETERMINATION OF THE TMDL ____________________41

6.1 Expression and Allocation of the TMDL ___________________________41

6.2 Load Allocation _______________________________________________42

6.3 Wasteload Allocation___________________________________________42

6.3.1 NPDES Wastewater Discharges ______________________________42

6.3.2 NPDES Stormwater Discharges_______________________________42

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

6.4 Margin of Safety _______________________________________________42

Chapter 7: NEXT STEPS: IMPLEMENTATION PLAN 

DEVELOPMENT AND BEYOND _____________________43

7.1 Basin Management Action Plan __________________________________43

References _______________________________________________44

Appendices _______________________________________________45

Appendix A: Background Information on Federal and State Stormwater 

Programs_____________________________________________________45

Appendix B: Historical DO, Corrected Chla, TN, and TP Observations in 

Spruce Creek, 1991–2006 _______________________________________46

Appendix C: Kruskal–Wallis Analysis of DO, DOSAT, Corrected Chla, 

TN, and TP Observations versus Season in Spruce Creek ____________60

Appendix D: Kruskal–Wallis Analysis of DO, DOSAT, Corrected Chla, 

TN, and TP Observations versus Month in Spruce Creek _____________62

Appendix E: Chart of DO, DOSAT, Corrected Chla, TN, and TP 

Observations by Season, Station, and Year in Spruce Creek __________65

Appendix F: Chart of Rainfall for Daytona International Airport, 1948–

2006 _________________________________________________________75

Appendix G: Spearman Correlation Matrix Analysis for Water Quality 

Parameters in Spruce Creek _____________________________________76

Appendix H: Linear Regression Analysis of DO and Corrected Chla 

Observations versus Nutrients and BOD in Spruce Creek ____________80

Appendix I: Monthly and Annual Precipitation at Daytona International 

Airport, 1948–2006 _____________________________________________85

Appendix J: Annual and Monthly Average Precipitation at Daytona 

International Airport ____________________________________________87

Appendix K: Response to Comments Following the January 15, 2008 

Public Meeting ________________________________________________88

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

List of Tables 

Table 2.1. Summary of DO Data by Month for the Verified Period 

(January 1, 1999 – June 30, 2006) _____________________________7

Table 2.2. Summary of DO Data by Season for the Verified Period 

(January 1, 1999 – June 30, 2006) _____________________________7

Table 2.3. Summary of DO Data by Year for the Verified Period 

(January 1, 1999 – June 30, 2006) _____________________________7

Table 2.4. Summary of Annual Average Corrected Chla for the 

Verified Period (January 1, 1999 – June 30, 2006) _________________8

Table 4.1. Classification of Land Use Categories in the Spruce Creek 

Watershed _______________________________________________14

Table 4.2. Description of Hydrologic Soil Classes from the SSURGO 

Database ________________________________________________17

Table 4.3. Estimated Average Household Size in the Spruce Creek 

Watershed _______________________________________________21

Table 4.4. Estimated Nitrogen and Phosphorus Annual Loading from 

Septic Tanks in the Spruce Creek Watershed ____________________21

Table 4.5. Estimated Loading from Wastewater Collection Systems 

in the Spruce Creek Watershed_______________________________21

Table 4.6. Estimated Annual Average TN and TP Loads from 

Agriculture in the Spruce Creek Watershed______________________22

Table 4.7. Estimated Urban and Built-up Annual Nitrogen and 

Phosphorus Loading in the Spruce Creek Watershed______________23

Table 4.8. Estimated Annual Nitrogen and Phosphorus Loading to 

WBID 2674A from WBID 2674, 1991–2005______________________23

Table 4.9. Summary of Estimated Potential Annual Nitrogen and 

Phosphorus Loading from Various Sources in the Spruce 

Creek Watershed __________________________________________24

Table 5.1. Physical and Statistical Summaries for USGS Gaging 

Sites in the Spruce Creek Watershed __________________________26

Table 5.2. Sampling Station Summary for the Spruce Creek 

Watershed _______________________________________________27

Table 5.3. Statistical Summary of Historical Data for Spruce Creek____________28

Table 5.4. Calculation of TP Reductions for the DO TMDL for Spruce 

Creek ___________________________________________________35

Table 5.5. Calculation of BOD Reductions for the DO TMDL for 

Spruce Creek _____________________________________________39

Table 5.6. Monthly and Seasonal Exceedance Rates for DO_________________40

Table 6.1. TMDL Components for Spruce Creek __________________________42

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

List of Figures 

Figure 1.1. Location of Spruce Creek and Major Geopolitical Features 

in the Upper East Coast Basin_________________________________2

Figure 1.2. Spruce Creek, WBID 2674A __________________________________3

Figure 1.3. WBIDs in the Halifax River Planning Unit ________________________4

Figure 4.1. Location of Permitted Facilities in the Spruce Creek 

Watershed _______________________________________________12

Figure 4.2. Jurisdictional Areas of Phase II NPDES MS4 Permits in 

the Spruce Creek Watershed_________________________________13

Figure 4.3. Principal Land Uses in the Spruce Creek Watershed ______________16

Figure 4.4. Hydrologic Soil Groups Distribution in the Spruce Creek 

Watershed _______________________________________________18

Figure 5.1. Daily Discharge Recorded at USGS Gage 02248053: 

Spruce Creek Near New Smyrna Beach ________________________25

Figure 5.2. Historical Sampling Sites in the Spruce Creek Watershed __________29

Figure 5.3. Historical DO Observations for Spruce Creek ____________________30

Figure 5.4. Historical Corrected Chla Observations for Spruce Creek___________30

Figure 5.5. Historical TN Observations for Spruce Creek ____________________31

Figure 5.6. Historical TP Observations for Spruce Creek ____________________31

Figure 5.7. Relationship Between DO and TP Observations for 

Spruce Creek _____________________________________________33

Figure 5.8. Relationship Between DO and BOD Observations for 

Spruce Creek _____________________________________________34

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Florida Department of Environmental Protection 

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Websites 

Florida Department of Environmental Protection, Bureau of 

Watershed Management 

TMDL Program 

http://www.dep.state.fl.us/water/tmdl/index.htm

Identification of Impaired Surface Waters Rule 

http://www.dep.state.fl.us/water/tmdl/docs/AmendedIWR.pdf

STORET Program 

http://www.dep.state.fl.us/water/storet/index.htm

2006 305(b) Report 

http://www.dep.state.fl.us/water/tmdl/docs/2006_Integrated_Report.pdf

Criteria for Surface Water Quality Classifications 

http://www.dep.state.fl.us/water/wqssp/classes.htm

Basin Status Report for the Upper East Coast Basin 

http://www.dep.state.fl.us/water/basin411/uppereast/status.htm

U.S. Environmental Protection Agency, National STORET Program 

http://www.epa.gov/storet/

Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Chapter 1: INTRODUCTION 

1.1 Purpose of Report 

This report presents the Total Maximum Daily Load (TMDL) for dissolved oxygen (DO) and 

nutrients for Spruce Creek in the Halifax River Planning Unit of the Upper East Coast Basin. 

The creek was verified as impaired for both DO and nutrients, and was included on the Verified 

List of impaired waters for the Upper East Coast Basin that was adopted by Secretarial Order in 

December 2007. This TMDL establishes the allowable loadings to Spruce Creek that would 

restore the waterbody so that it meets its applicable water quality criteria for both DO and 

nutrients. 

1.2 Identification of Waterbody 

Spruce Creek is located in Volusia County, in east-central Florida, near New Smyrna Beach. It 

forms in wetlands west of New Smyrna Beach and flows north, then turns east and discharges 

to the Intracoastal Waterway (ICWW) (Figures 1.1 and 1.2). Spruce Creek is approximately 

20.1 miles long and is a second-order stream that is tidally influenced in its lower reaches. 

Additional information about the creek’s hydrology and geology are available in the Basin Status 

Report for the Upper East Coast Basin (Florida Department of Environmental Protection 

[Department], 2005). 

Spruce Creek and certain tributaries were designated as Outstanding Florida Waters (OFWs) in 

1991. Volusia County initiated a study in May 1994 to evaluate the impact of stormwater on 

overall water quantity and water quality in the designated OFW areas of Spruce Creek and 

Rose Bay (Volusia County, 1996). OFW provisions require 50 percent greater treatment for the 

direct discharge of stormwater to an OFW. Volusia County is currently working on an update to 

the Spruce Creek/Rose Bay master plan. 

 

For assessment purposes, the Department has divided the Upper East Coast Basin into water 

assessment polygons with a unique waterbody identification (WBID) number for each 

watershed or stream reach. Spruce Creek consists of two segments, WBIDs 2674 and 2674A, 

as shown in Figure 1.1; this TMDL addresses the DO and nutrient impairments in WBID 2674A. 

The combined drainage area of WBIDs 2674 (17.67 square miles) and 2674A (13.10 square 

miles) is 30.77 square miles. Note that the USGS gaging site on Spruce Creek (Gage 

02248053) discussed in Chapter 5 has a drainage area of 60.7 square miles and represents 

additional contributions outside these two WBIDs. 

Spruce Creek is part of the Halifax River Planning Unit. Planning units are groups of smaller 

watersheds (WBIDs) that are part of a larger basin unit, in this case the Upper East Coast 

Basin. The Halifax River Planning Unit consists of 53 WBIDs. Figure 1.3 shows the locations 

of these WBIDs, Spruce Creek’s location in the planning unit, and a list of the other WBIDs in 

the planning unit. Since both WBIDs are listed as Spruce Creek, for clarity a number of the 

figures refer to WBID 2674A as Spruce Creek North. 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Figure 1.1. Location of Spruce Creek and Major Geopolitical 

Features in the Upper East Coast Basin 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Figure 1.2. Spruce Creek, WBID 2674A 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Figure 1.3. WBIDs in the Halifax River Planning Unit 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

1.3 Background 

This report was developed as part of the Department’s watershed management approach for 

restoring and protecting state waters and addressing TMDL Program requirements. The 

watershed approach, which is implemented using a cyclical management process that rotates 

through the state’s 52 river basins over a 5-year cycle, provides a framework for implementing 

the TMDL Program–related requirements of the 1972 federal Clean Water Act and the 1999 

Florida Watershed Restoration Act (FWRA) (Chapter 99-223, Laws of Florida). 

A TMDL represents the maximum amount of a given pollutant that a waterbody can assimilate 

and still meet water quality standards, including its applicable water quality criteria and its 

designated uses. TMDLs are developed for waterbodies that are verified as not meeting their 

water quality standards. They provide important water quality restoration goals that will guide 

restoration activities. 

This TMDL Report will be followed by the development and implementation of a Basin 

Management Action Plan, or BMAP, to reduce the amount of nutrients that caused the verified 

impairment of Spruce Creek. These activities will depend heavily on the active participation of 

the St. Johns River Water Management District (SJRWMD), Volusia County, local governments, 

local businesses, and other stakeholders. The Department will work with these organizations 

and individuals to undertake or continue reductions in the discharge of pollutants and achieve 

the established TMDLs for impaired waterbodies. 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Chapter 2: DESCRIPTION OF WATER QUALITY 

PROBLEM 

2.1 Statutory Requirements and Rulemaking History 

Section 303(d) of the federal Clean Water Act requires states to submit to the U.S. 

Environmental Protection Agency (EPA) a list of surface waters that do not meet applicable 

water quality standards (impaired waters) and establish a TMDL for each pollutant causing 

impairment of these waters on a schedule. The Department has developed such lists, 

commonly referred to as 303(d) lists, since 1992. The list of impaired waters in each basin, 

referred to as the Verified List, is also required by the FWRA (Subsection 403.067[4], Florida 

Statutes [F.S.]), and the state’s 303(d) list is amended annually to include basin updates. 

Florida’s 1998 303(d) list included 15 waterbodies and 50 parameters in the Upper East Coast 

Basin. However, the FWRA (Section 403.067, F.S.) stated that all previous Florida 303(d) lists 

were for planning purposes only and directed the Department to develop, and adopt by rule, a 

new science-based methodology to identify impaired waters. After a long rule-making process, 

the Environmental Regulation Commission adopted the new methodology as Rule 62-303, 

Florida Administrative Code (F.A.C.) (Identification of Impaired Surface Waters Rule, or IWR), in 

April 2001; the rule was revised in 2006 and 2007. 

2.2 Information on Verified Impairment 

The Department used the IWR to assess water quality impairments in Spruce Creek and has 

verified that the creek is impaired for DO and nutrients, based on data in the Department’s IWR 

database. Tables 2.1 through 2.3 summarize the DO data for the verification period, which for 

Group 5 waters was January 1, 1999, through June 30, 2006, by month, season, and year, 

respectively. 

There is a 23.4 percent overall exceedance rate for DO in Spruce Creek during the verified 

period. Exceedances occur in all seasons and in all months except March (Tables 2.1 and 2.2). 

During the verified period, samples ranged from 0.01 to 9.20 milligrams per liter (mg/L). As DO 

solubility is influenced by both salinity and water temperature, ranges in DO saturation were 

also evaluated. DO saturation ranged from 0.1 to 120.9 percent, with fewer than 10 percent of 

the saturation values greater than 100 percent. Fewer than 10 percent of the DO saturation 

values were less than 34 percent. 

When aggregating data by season, the lowest percentage of exceedances occurred in the 

winter and the highest in spring. Possible relationships between DO and other water quality 

parameters will be further assessed using the complete historical dataset in Chapter 5. 

Of the 17 sites with historical data, 10 were sampled during the verified period. Section 5.1

discusses the sampling stations further. 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Table 2.1. Summary of DO Data by Month for the Verified Period 

(January 1, 1999 – June 30, 2006) 

Month N Minimum Maximum Median Mean No. of 

Exceedances 

% 

Exceedance 

Mean 

Precipitation 

January 11 2.43 8.72 6.64 5.70 4 36.36% 2.51 

February 21 0.01 8.97 5.73 5.75 3 14.29% 2.89 

March 12 1.83 9.2 7.13 6.78 1 8.33% 3.61 

April 15 4.13 7.72 6.38 6.03 0 0.00% 2.35 

May 15 0.53 7.18 4.92 4.19 6 40.00% 2.86 

June 17 0.95 7.1 3.76 4.11 9 52.94% 6.15 

July 7 0.79 6.03 4.10 3.96 2 28.57% 5.65 

August 24 0.22 6.93 4.33 4.45 3 12.50% 6.48 

September 7 0.28 6.69 4.40 3.85 3 42.86% 6.92 

October 11 2.77 6.17 3.54 4.06 6 54.55% 4.9 

November 16 2.64 7.4 5.74 5.51 2 12.50% 2.66 

December 15 3.51 9.2 6.42 6.21 1 6.67% 2.48 

DO units are mg/L. 

Mean precipitation is for Daytona Beach International Airport, in inches. 

Table 2.2. Summary of DO Data by Season for the Verified Period 

(January 1, 1999 – June 30, 2006) 

Season N Minimum Maximum Median Mean No. of 

Exceedances 

% 

Exceedance 

Mean Total 

Precipitation 

Winter 44 0.01 9.2 6.22 6.020568 8 18.18% 9.01 

Spring 47 0.53 7.72 5.19 4.750213 15 31.91% 11.36 

Summer 38 0.22 6.93 4.33 4.248026 8 21.05% 19.05 

Fall 42 2.64 9.2 5.46 5.382143 9 21.43% 10.04 

DO units are mg/L. 

Mean total precipitation is for Daytona Beach International Airport, in inches. 

Table 2.3. Summary of DO Data by Year for the Verified Period 

(January 1, 1999 – June 30, 2006) 

Year N Minimum Maximum Median Mean No. of 

Exceedances 

% 

Exceedance 

Total 

Precipitation 

1999 44 0.22 8.31 4.39 4.46 14 31.82% 46.37 

2000 14 0.79 8.14 4.22 4.41 6 42.86% 40.16 

2001 16 0.01 8.97 4.84 4.28 5 31.25% 58.27 

2002 7 4.69 7.73 7.02 6.43 0 0.00% 59.94 

2003 27 2.53 8.5 5.28 5.23 7 25.93% 57.3 

2004 14 3.08 9.2 5.56 5.71 3 21.43% 62.97 

2005 43 3.68 8.52 5.95 5.64 5 11.63% 65.77 

2006 6 5.34 8.72 6.45 6.74 0 0.00% 31.36 

DO units are mg/L. 

Total precipitation is for Daytona Beach International Airport, in inches. 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Table 2.4 summarizes annual average corrected chlorophyll a (chla) concentrations based on 

the IWR. During the verified period, the 11 micrograms per liter (μg/L) threshold was exceeded 

in 2003. In 2002, 2004, and 2006, there were insufficient data to calculate an annual average. 

Table 2.4. Summary of Annual Average Corrected Chla for the 

Verified Period (January 1, 1999 – June 30, 2006) 

Year Mean Exceedance 

1999 5.30 no 

2000 3.82 no 

2001 5.96 no 

2002 

2003 12.05 yes 

2004 

2005 2.95 no 

2006 

Corrected chla units are ug/L. 

Historical threshold is 5.60 μg/L based on the 1991–1995 period. 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Chapter 3. DESCRIPTION OF APPLICABLE WATER 

QUALITY STANDARDS AND TARGETS 

3.1 Classification of the Waterbody and Criteria Applicable to the TMDL 

Florida’s surface waters are protected for five designated use classifications, as follows: 

Class I Potable water supplies 

Class II Shellfish propagation or harvesting 

Class III Recreation, propagation, and maintenance of a healthy, wellbalanced population of fish and wildlife 

Class IV Agricultural water supplies 

Class V Navigation, utility, and industrial use (there are no state 

waters currently in this class) 

Spruce Creek (WBID 2674A) is a Class III marine waterbody, with a designated use of 

recreation, propagation, and the maintenance of a healthy, well-balanced population of fish and 

wildlife. The Class III water quality criteria applicable to the impairment addressed by this TMDL 

are for DO and nutrients. 

3.2 Applicable Water Quality Standards and Numeric Water Quality Target 

3.2.1 Dissolved Oxygen Criterion 

Numeric criteria for DO are expressed in terms of minimum and daily average concentrations. 

The water quality criterion for the protection of Class III marine waters, as established by Rule 

62-302, F.A.C., states the following: 

Dissolved Oxygen Criteria: 

Shall not average less than 5.0 in a 24-hour period and shall never be less 

than 4.0. Normal daily and seasonal fluctuations above these levels shall be 

maintained. 

The nutrient criterion in Rule 62-302, F.A.C., is expressed as a narrative: 

Nutrients: 

In no case shall nutrient concentrations of a body of water be altered so as 

to cause an imbalance in natural populations of aquatic flora or fauna [Note: 

For Class III waters in the Everglades Protection Area, this criterion has 

been numerically interpreted for phosphorus in Section 62-302.540, F.A.C.]. 

To assess whether this narrative criterion was being exceeded, the IWR provides thresholds for 

nutrient impairment in estuaries based on annual average chla levels. The following language 

is found in Rule 62-303, F.A.C.: 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

62-303.353 Nutrients in Estuaries and Open Coastal Waters. 

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

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

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

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

consecutive years. 

62-303.450 Interpretation of Narrative Nutrient Criteria. 

(1) A water shall be placed on the verified list for impairment due to nutrients 

if there are sufficient data from the last five years preceding the planning list 

assessment, combined with historical data (if needed to establish historical 

chlorophyll a levels or historical TSIs), to meet the data sufficiency 

requirements of subsection 62-303.350(2), FA.C. If there are insufficient 

data, additional data shall be collected as needed to meet the requirements. 

Once these additional data are collected, the Department shall determine if 

there is sufficient information to develop a site-specific threshold that better 

reflects conditions beyond which an imbalance in flora or fauna occurs in the 

water segment. If there is sufficient information, the Department shall reevaluate the data using the site-specific thresholds. If there is insufficient 

information, the Department shall re-evaluate the data using the thresholds 

provided in Rules 62-303.351-.353, F.A.C., for streams, lakes, and 

estuaries, respectively. In any case, the Department shall limit its analysis to 

the use of data collected during the five years preceding the planning list 

assessment and the additional data collected in the second phase. If 

alternative thresholds are used for the analysis, the Department shall 

provide the thresholds for the record and document how the alternative 

threshold better represents conditions beyond which an imbalance in flora or 

fauna is expected to occur. 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Chapter 4: ASSESSMENT OF SOURCES 

4.1 Types of Sources 

An important part of the TMDL analysis is the identification of pollutant source categories, 

source subcategories, or individual sources of pollutants in the watershed and the amount of 

pollutant loading contributed by each of these sources. Sources are broadly classified as either 

“point sources” or “nonpoint sources.” Historically, the term “point sources” has meant 

discharges to surface waters that typically have a continuous flow via a discernable, confined, 

and discrete conveyance, such as a pipe. Domestic and industrial wastewater treatment 

facilities (WWTFs) are examples of traditional point sources. In contrast, the term “nonpoint 

sources” was used to describe intermittent, rainfall-driven, diffuse sources of pollution 

associated with everyday human activities, including runoff from urban land uses, agriculture, 

silviculture, and mining; discharges from failing septic systems; and atmospheric deposition. 

However, the 1987 amendments to the Clean Water Act redefined certain nonpoint sources of 

pollution as point sources subject to regulation under the EPA’s National Pollutant Discharge 

Elimination System (NPDES) Program. These nonpoint sources included certain urban 

stormwater discharges, including those from local government master drainage systems, 

construction sites over five acres, and a wide variety of industries (see Appendix A for 

background information on the federal and state stormwater programs). 

To be consistent with Clean Water Act definitions, the term “point source” will be used to 

describe traditional point sources (such as domestic and industrial wastewater discharges) AND 

stormwater systems requiring an NPDES stormwater permit when allocating pollutant load 

reductions required by a TMDL (see Section 6.1). However, the methodologies used to 

estimate nonpoint source loads do not distinguish between NPDES stormwater discharges and 

non-NPDES stormwater discharges, and as such, this source assessment section does not 

make any distinction between the two types of stormwater. 

4.2 Potential Sources of Nutrients in the Spruce Creek Watershed 

4.2.1 Point Sources 

There are no NPDES wastewater facilities located in the watershed. Figure 4.1 shows the 

location of a state-permitted industrial facility along with partial coverage of septic tanks. The 

Volusia County Department of Public Works Spruce Creek Reverse Osmosis Facility 

(FLA0185086) discharges demineralization concentrate to a land application system (a 2.3-acre 

impoundment). It has a monthly design discharge flow of 0.15 million gallons per day (mgd). 

As shown in Figure 4.1, the city of Port Orange provides sewer service to portions of the 

watershed. There are currently approximately 4,700 households connected to the city’s 

wastewater system in WBID 2674A, and there are also private sewer lines in the Spruce Creek 

Fly-In subdivision (a portion of which is included in this WBID) (C. Craig, city of Port Orange, 

personal communication). 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Figure 4.1. Location of Permitted Facilities in the Spruce Creek 

Watershed 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Municipal Separate Storm Sewer System Permittees 

Volusia County, Port Orange, Ponce Inlet, and New Smyrna Beach have Phase II NPDES 

municipal separate storm sewer system (MS4) permits (FLR04E033, FLR04E014, FLR04E071, 

and FLR04E035, respectively) that may cover portions of the Spruce Creek watershed. Figure 

4.2, provided by BCI Engineers & Scientists, Inc. (C. Farmer, personal communication), 

illustrates the juridictional areas for each permittee.

Figure 4.2. Jurisdictional Areas of Phase II NPDES MS4 Permits in 

the Spruce Creek Watershed 

4.2.2 Land Uses and Nonpoint Sources 

Nutrient loadings to Spruce Creek are generated from nonpoint sources in the watershed. 

These potential sources include loadings from surface runoff, ground water inflow, leakage from 

collection systems, and septic tanks. 

Land Uses 

The spatial distribution and acreage of different land use categories were identified using the 

2004 land use coverage contained in the Department’s geographic information system (GIS) 

library, initially provided by the SJRWMD. Land use categories and acreages in the watershed 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

were aggregated using the Level 3 codes tabulated in Table 4.1. Figure 4.3 shows the 

principal land uses in the watershed aggregated to the Level 1 land use codes. 

The Spruce Creek watershed is an area that is facing increased development pressures. As 

Table 4.1 shows, urban and built-up areas represent 38.4 percent of the area (medium-density 

residential, 14.7 percent) followed by forest (22.2 percent), and wetlands (21.3 percent). 

Table 4.1. Classification of Land Use Categories in the Spruce Creek 

Watershed 

Level 3 

Land Use Code Attribute Acres % of Total 

1200 Residential, medium density–2-5 dwelling units/acre 1,174.93 14.73 

4110 Pine flatwoods 786.93 9.87 

4340 Upland mixed coniferous/hardwood 782.61 9.81 

6420 Saltwater marshes 752.96 9.44 

1100 Residential, low density–less than 2 dwelling units/acre 593.39 7.44 

1300 Residential, high density–6 or more dwelling units/acre 398.58 5.00 

6170 Mixed wetland hardwoods 384.12 4.82 

5300 Reservoirs–pits, retention ponds, dams 251.94 3.16 

1820 Golf courses 233.09 2.92 

1180 Rural residential 227 2.85 

2130 Woodland pastures 187.42 2.35 

6300 Wetland forested mixed 176.85 2.22 

8140 Roads and highways (divided 4-lanes with medians) 174.32 2.19 

1290 Medium density under construction 170.21 2.13 

2110 Improved pastures (monoculture, planted forage crops) 167.94 2.11 

6120 Mangrove swamps 151.72 1.90 

3200 Shrub and brushland (wax myrtle or saw palmetto, 

occasionally scrub) 126.83 1.59 

5100 Streams and waterways 123.03 1.54 

1400 Commercial and services 109.41 1.37 

3300 Mixed upland nonforested 106.02 1.33 

3100 Herbaceous upland nonforested 91.91 1.15 

8110 Airports 86.42 1.08 

6460 Mixed scrub-shrub wetland 85.51 1.07 

6210 Cypress 70.64 0.89 

4200 Upland hardwood forests 69.52 0.87 

1700 Institutional 57.13 0.72 

4130 Sand pine 53.55 0.67 

4410 Coniferous pine 52.89 0.66 

2510 Horse farms 48.97 0.61 

1390 High density under construction 40.1 0.50 

1190 Low density under construction 30.79 0.39 

Florida Department of Environmental Protection 

14
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Level 3 Attribute Acres % of Total Land Use Code 

6410 Freshwater marshes 30.16 0.38 

4430 Forest regeneration 25.28 0.32 

1900 Open land 22.73 0.28 

1850 Parks and zoos 19.87 0.25 

6250 Hydric pine flatwoods 19.59 0.25 

5200 Lakes 18.06 0.23 

6440 Emergent aquatic vegetation 13.98 0.18 

7430 Spoil areas 12.03 0.15 

2430 Ornamentals 9.63 0.12 

6180 Cabbage palm hammock 7.62 0.10 

1860 Community recreational facilities 7.52 0.09 

8330 Water supply plants 4.81 0.06 

5400 Bays and estuaries 4.62 0.06 

8310 Electrical power facilities 4.57 0.06 

6430 Wet prairies 3.38 0.04 

8370 Surface water collection basins 3.29 0.04 

4400 Tree plantations 2.32 0.03 

TOTAL: 7,976.19 100.00% 

Florida Department of Environmental Protection 

15
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Figure 4.3. Principal Land Uses in the Spruce Creek Watershed 

Florida Department of Environmental Protection 

16
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Soil Characteristics 

The Soil Survey Geographic Database (SSURGO) in the Department’s GIS database from the 

SJRWMD was accessed to provide coverage of hydrologic soil groups in the Spruce Creek 

watershed (Figure 4.4). Table 4.2 briefly describes the major hydrology soil classes. Soil 

groups A and B/D are the most common in the watershed, with type D found in the lower portion 

of the watershed and along the stream corridor. 

Table 4.2. Description of Hydrologic Soil Classes from the SSURGO 

Database 

Hydrology Class Description 

A High infiltration rates. Soils are deep, well-drained 

to excessively drained sands and gravels.

A/D Drained/undrained hydrology class of soils that can 

be drained and are classified.

B

Moderate infiltration rates. Deep and moderately 

deep, moderately well- and well-drained soils that 

have moderately coarse textures.

B/D Drained/undrained hydrology class of soils that 

have moderately coarse textures. 

C

Slow infiltration rates. Soils with layers impeding 

downward movement of water, or soils that have 

moderately fine or fine textures.

C/D Drained/undrained hydrology class of soils that can 

be drained and classified.

D

Very slow infiltration rates. Soils are clayey, have a 

high water table, or are shallow to an impervious 

layer.

Population 

According to the U.S Census Bureau, census block population densities in the Spruce Creek 

watershed in 2000 ranged from 0 to 12,019 persons per square mile, with an average of 600 

persons per square mile (Figure 4.5). Based on this average, the estimated population in the 

Spruce Creek watershed is 7,472. A more detailed analysis was completed by obtaining 

population and housing unit information from the 2000 Census at the block level and using GIS 

to estimate the fraction of each block in the watershed. The fractional area was then applied to 

the block information to estimate the population and number of housing units. Based on Table 

4.3, the population in the watershed is estimated at 8,587 along with 3,666 housing units. 

The Census Bureau reports that, for all of Volusia County, the total population for 2000 was 

approximately 443,343, with 211,938 housing units and an average occupancy rate of 87.2 

percent (184,723 units). For all of Volusia County, the bureau reported a housing density of 192 

houses per square mile. Thus Volusia County ranks 13th in housing densities and population in 

Florida (U.S. Census Bureau Website, 2000). The estimated average housing density in 

Spruce Creek is 280 residences per square mile, based on population. 

Florida Department of Environmental Protection 

17
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Figure 4.4. Hydrologic Soil Groups Distribution in the Spruce Creek 

Watershed 

Florida Department of Environmental Protection 

18
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Figure 4.5. Population Density in the Spruce Creek Watershed 

 

Florida Department of Environmental Protection 

19
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Septic Tanks 

Based on the 2000 Census figure of 211,938 housing units and the Florida Department of 

Health (FDOH) estimate of 96,633 permitted septic tanks in Volusia County, approximately 45 

percent of the households in the county are using septic tanks. FDOH reports that as of fiscal 

year 2005–06, there were 96,633 permitted septic tanks in Volusia County (FDOH Website, 

2006). From fiscal years 1991–2006 (missing 1992–93), 13,436 permits for repairs were 

issued, for an average of approximately 960 repairs annually (FDOH Website, 2006) 

countywide. Simply dividing the number of septic tank repairs by the total number of septic 

tanks yields an estimated failure rate of 13.9 percent. Assuming that this failure rate is 

representative of the 14-year period for which data are available, this suggests a rate of 1 

percent per year. 

As noted previously, there were an estimated 8,587 persons and 3,666 households in the 

Spruce Creek watershed. The average household in the watershed has 2.34 persons (see 

Table 4.3). There are no permitted domestic wastewater facilities in the watershed; however, 

the city of Port Orange provides sewer service to portions of the watershed. Since the city is 

experiencing rapid population growth, information on its gravity sewer lines (C. Craig, personal 

communication) was overlaid on a 2004 aerial of the watershed to obtain an estimate of the 

number of households connected to the city wastewater system for comparison with the 2000 

Census data. The number of residences connected to the city wastewater system was 

approximately 3,050. 

Using this estimate, along with the 2000 Census calculation of 3,666 households, suggests that 

approximately 616 residences are using septic tanks (the partial coverage in Figure 4.1

included 219 septic tanks). This indicates that approximately 17 percent of the households are 

using septic tanks, or about one-third of the countywide estimate. Using 70 gallons/day/person 

(EPA, 1999), and drainfield total nitrogen (TN) and total phosphorus (TP) concentrations of 36 

mg/L and 15 mg/L, respectively, potential annual ground water loads of TN and TP were 

calculated. As in the case of earlier estimates, this is a screening level calculation, and soil 

types, the age of the system, vegetation, proximity to a receiving water, and other factors will 

influence the degree of attenuation of this load (Table 4.4). 

Leaking or Overflowing Wastewater Collection Systems 

Earlier it was estimated that approximately 3,050 households in the watershed are connected to 

the city of Port Orange wastewater facility. Using 2.34 people per home and a 70 gallon per 

person per day discharge, a daily flow of approximately 1.89 x 105

 L is transported through the 

collection system. An EPA Region 4 memorandum on estimating water quality loadings from 

MS4 areas (EPA, 2002) suggests that a 5 percent leakage rate from collection systems is 

realistic. This information and EPA values for nitrogen and phosphorus concentrations in raw 

sewage yield potential annual loadings of nitrogen and phosphorus of 2,739 lbs/yr and 1,141 

lbs/yr, respectively (Table 4.5). 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Table 4.3. Estimated Average Household Size in the Spruce Creek 

Watershed 

Tract Block Population Housing Units 

824.10 1 0 0 

825.05 1 617 213 

825.05 2 2188 757 

825.05 3 835 225 

825.07 1 101 51 

828 1 744 397 

829.01 1 65 22 

832.04 3 4337 2001 

Total 8,587 3,666 

AVERAGE HOUSEHOLD SIZE: 2.34 

Data from U.S. Census Bureau Website, 2005, based on Volusia County blocks that are present in the Spruce Creek watershed. 

Table 4.4. Estimated Nitrogen and Phosphorus Annual Loading from 

Septic Tanks in the Spruce Creek Watershed 

Estimated 

No. 

Households 

on Septic 

Estimated 

No. 

Persons 

Per 

Household1

Gallons/ 

Person/ 

Day2

TN in 

Drainfield 

(mg/L) 

TP in 

Drainfield 

(mg/L) 

Estimated 

Annual TN 

Load 

(lbs/yr) 

Estimated 

Annual TP 

Load 

(lbs/yr) 

616 2.34 70 36 15 11,065 4,611 

1

 U.S Census Bureau; see Table 4.3 for more information on this estimate. 2

 EPA, 1999. 

Table 4.5. Estimated Loading from Wastewater Collection Systems 

in the Spruce Creek Watershed 

Parameter 

Estimated 

Homes on 

Central 

Sewer 

Estimated 

Daily Flow 

(L)

Daily 

Leakage 

(L) 

Raw Sewage 

(mg/L) 

Estimated 

Load 

(lbs/yr) 

Nitrogen 3,050 1.89 x 106 9.45 x 104 36 2,739 

Phosphorus 3,050 1.89 x 106 9.45 x 104 15 1,141 

Florida Department of Environmental Protection 

21
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

4.3 Source Summary 

4.3.1 Summary of Nutrient Loadings to Spruce Creek from Various 

Sources 

Agriculture 

Aggregating land use to Level 1 for the Spruce Creek watershed yields 414 acres in agriculture. 

Harper et al. (2003) summarized a number of stormwater studies conducted in Florida, and 

based on those studies provided mean stormwater water quality parameters and hydrologic 

characteristics for a variety of land uses, including pastureland. According to Harper et al. 

(2003), mean stormwater concentrations for TN, TP, and biochemical oxygen demand (BOD) 

from pastureland are 2.48 mg/L, 0.476 mg/L, and 5.1 mg/L, respectively. The report also gave 

a mean runoff coefficient of 0.355. 

A more detailed loading analysis could be performed based on soil types, annual rainfall 

amounts, and specific agricultural activities in the watershed. However, as a screening 

analysis, annual loads taken from the BASINS 3.0 User Manual, Appendix IV (EPA, 2001), for 

pasturelands in Florida were used as preliminary estimates (Table 4.6). 

Table 4.6. Estimated Annual Average TN and TP Loads from Agriculture in 

the Spruce Creek Watershed 

Agricultural 

Acreage TN (lbs/ac/yr) TN load (lbs/yr) TP (lbs/ac/yr) TP load (lbs/yr) 

414 5.60 2,318 0.60 248 

Source: EPA, 2001. 

Urban Areas 

There are 3,085 acres in the Level 1 category of urban and built-up in the watershed and 174 

acres of highways. According to Harper et al. (2003), mean stormwater concentrations for TN, 

TP, and BOD from single-family residential lands are 2.18 mg/L, 0.335 mg/L, and 7.4 mg/L, 

respectively. The report also gave a mean runoff coefficient of 0.33. Mean stormwater 

concentrations for TN, TP, and BOD from multifamily residential lands are 2.42 mg/L, 0.49 

mg/L, and 11.0 mg/L, respectively. The report also gave a mean runoff coefficient of 0.675. 

A more detailed loading analysis could be performed based on soil types, annual rainfall 

amounts, and specific agricultural activities in the watershed. However, as a screening 

analysis, annual loads taken from the BASINS 3.0 User Manual, Appendix IV (EPA, 2001), for 

pasturelands in Florida were used (Table 4.7). Medium- and high-density land uses were 

combined into the multifamily category, and some land uses in Level 1 were not included in the 

loading estimate (for example, golf courses). 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Table 4.7. Estimated Urban and Built-up Annual Nitrogen and 

Phosphorus Loading in the Spruce Creek Watershed 

Urban 

Category Acreage TN 

(lbs/ac/yr) 

TN load 

(lbs/yr) 

TP 

(lbs/ac/yr) 

TP load 

(lbs/yr) 

Low-Density 

residential 851.2 4.43 3,771 0.47 400 

Multifamily 

residential 1,783.8 7.07 12,612 1.97 3,514 

Commercial 109.4 9.48 1,037 2.05 224 

Highway 174.3 6.25 1,089 2.50 436 

Open Lands 22.7 2.32 53 0.16 4 

Totals 2,941.4 18,562 4,578 

Source: BASINS 3.0 Users Manual, Appendix IV. 

Upstream Drainage Area of Spruce Creek 

As discussed earlier, Spruce Creek is divided into two WBIDs, and this TMDL focuses on the 

lower WBID (2674A). A simple estimate of annual TN and TP loading from the upper WBID 

was obtained by multiplying annual average flows from U.S. Geological Survey (USGS) Gage 

02248000 and nutrient concentrations (Table 4.8). 

Table 4.8. Estimated Annual Nitrogen and Phosphorus Loading to 

WBID 2674A from WBID 2674, 1991–2005 

Year # TN 

Samples 

Mean TN 

(mg/L) 

# TP 

Samples 

Mean TP 

(mg/L) 

Avg. Flow 

(cfs) 

TN Load 

(lbs/yr) 

TP Load 

(lbs/yr) 

1991 7 1.49 7 0.159 53.9 158,420.3 16,827.4 

1992 5 1.42 5 0.152 23 64,301.3 6,883.0 

1993 3 0.98 3 0.147 13.2 25,373.2 3,811.6 

1995 40 1.23 40 0.213 41.1 99,911.6 17,261.9 

1996 42 0.92 42 0.188 37.7 67,960.2 13,957.7 

1997 43 0.99 43 0.141 15.3 29,759.2 4,241.0 

1998 43 1.23 43 0.119 47.1 114,184.1 11,035.0 

1999 43 1.00 42 0.118 41 80,790.7 9,515.5 

2000 41 0.88 41 0.085 4.6 7,937.9 770.5 

2001 42 1.08 42 0.120 63.7 135,359.7 15,048.1 

2002 42 0.92 42 0.095 25.3 45,609.0 4,740.3 

2003 42 1.08 42 0.101 39.1 82,778.6 7,805.3 

2004 37 1.07 37 0.112 42.3 88,931.1 9,321.5 

2005 50 1.32 50 0.141 50.5 131,241.9 14,020.9 

Average 1.08 0.131 80,897 9,660 

cfs – Cubic feet per second. 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Table 4.9 summarizes the various estimates from various anthropogenic sources. It is 

important to note that this is not a complete list and represents estimates of potential loadings. 

In addition, proximity to the waterbody, soil characteristics, and rainfall frequency and 

magnitude are just a few of the factors that could influence and determine the actual loadings 

from these sources that reach Spruce Creek. For example, where are the improved pasture 

and high-density residential areas relative to Spruce Creek, and is there a riparian buffer area 

between these land uses and the stream? What types of best management practices (BMPs), 

both structural and nonstructural, have been implemented for specific land uses in the 

watershed that reduce the actual nutrient loads delivered to Spruce Creek? Finally, what is the 

age and condition of the septic and collection systems and drainage characteristics in the 

watershed compared with the county overall that could affect assumptions about the 

assimilation and/or retention of nutrients? 

Table 4.9. Summary of Estimated Potential Annual Nitrogen and 

Phosphorus Loading from Various Sources in the Spruce 

Creek Watershed 

Source Total Nitrogen 

(lbs/yr) 

Total Phosphorus 

(lbs/yr) 

Septic Tanks 11,065 4,611 

Urban and Built-up 18,562 4,578 

Leaking Collection Systems 2,739 1.141 

Agriculture 2,318 248 

Upstream WBID 80,897 9,660 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Chapter 5: DETERMINATION OF ASSIMILATIVE 

CAPACITY 

5.1 Determination of Loading Capacity 

A USGS gaging site on Spruce Creek (02248053) has daily discharge data over the period from 

December 27, 2000, to September 30, 2006. As seen in Figure 5.1, the stream is tidally 

influenced at this location, with over 70 percent of the daily flows suggesting upstream transport. 

Another USGS gaging site farther upstream on Spruce Creek (02248000) has operated since 

1951 and is not tidally influenced. Table 5.1 provides physical and streamflow statistics for 

these two gages. 

Due to the tidal influence and limited period of record, annual nutrient loads were not estimated 

for WBID 2674A based on flow and instream nutrient measurements. The upstream gage flows 

were paired with observations as part of the correlation analysis and for the calculation of 

nutrient loads contributed from WBID 2674 to WBID 2674A. To determine the TMDL, 

relationships between DO and nutrients were examined to identify the reductions that would be 

required to meet applicable criteria. 

Figure 5.1. Daily Discharge Recorded at USGS Gage 02248053: 

Spruce Creek Near New Smyrna Beach 

USGS 02248053

-500

0

500

1000

1500

2000

2500

3000

3/15/2000

1/9/2001

11/5/2001

9/1/2002

6/28/2003

4/23/2004

2/17/2005

12/14/2005

10/10/2006

DATE

DISCHARGE (CFS)

Florida Department of Environmental Protection 

25
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Table 5.1. Physical and Statistical Summaries for USGS Gaging Sites 

in the Spruce Creek Watershed 

USGS Gages 

Gage # 02248000 02248053 

Drainage Area (square miles) 33.4 60.7 

Period of Record 10/2/1951 – Present 12/27/2000 – 9/30/2006 

Mean Basin Elevation (feet) 28 

Stream slope (feet/mile) 0.6 

Flow Duration 

1% (cfs) 372 1,102.6 

5% (cfs) 160 379.3 

10% (cfs) 83 255.7 

20% (cfs) 35 180 

25% (cfs) 25 154 

50% (cfs) 6.3 47.5 

70% (cfs) 2.4 -18 

75% (cfs) 1.9 -36.5 

90% (cfs) 0.92 -106.4 

95% (cfs) 0.59 -138.3 

99% (cfs) 0.29 -208.8 

5.1.1 Data Used in the Determination of the TMDL 

Seventeen sampling stations on Spruce Creek have historical DO observations (Figure 5.2). 

Five of the Department stations were established and sampled during 2005. Table 5.2 contains 

summary information on each of the stations. Table 5.3 provides a statistical summary of DO 

observations at each station, and Appendix B contains historical DO, corrected chla, TN, and 

TP observations from the sites for the planning and verified periods for WBID 2674A. Figure 

5.3 displays the historical observations of DO over time. DO exceedance rates by station range 

between 20 and 60 percent. A linear regression of DO versus sampling date in Figure 5.3

indicates no significant trend over time (R2

 = 0.0009). Appendix E contains plots of DO by 

season, station, and year. 

Figures 5.4 through 5.6 present historical corrected chla, TN, and TP observations, 

respectively. Linear regressions of each parameter versus sampling date indicate no significant 

trend over time (R2

 values for each < 0.08). Appendix E contains additional plots. 

Florida Department of Environmental Protection 

26
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Table 5.2. Sampling Station Summary for the Spruce Creek Watershed 

Station STORET ID Station Owner Years 

With Data N 

Spruce Creek Center Bridge on U.S. Hwy 1 21FLVEMDSC01 Volusia County 1991–98 77 

Spruce Creek West of SSC Railroad 21FLVEMDSC02 Volusia County 1991–98 77 

Spruce Creek West of Airport Rd 21FLVEMDSC04 Volusia County 1991–98 78 

Spruce Creek at Dock at Gamble Place 21FLVEMDSC05 Volusia County 1991–98 78 

Spruce Creek 100 M Upstream from ICWW 21FLSJWMSPRCR SJRWMD 1992 1 

Spruce Creek at Airport Rd 21FLSJWMUEC014 SJRWMD 1992–93 5 

Spruce Creek, from W. Side of Center 

Bridge on U.S. 1 21FLVEMDVC-071 Volusia County 1999–2006 35 

Spruce Creek, from Dock at Riverwood, 

W. of SCL Railroad 21FLVEMDVC-072 Volusia County 1999–2006 39 

Spruce Creek, from W. Side of Moody 

Bridge on Airport Rd 21FLVEMDVC-073 Volusia County 1999–2006 35 

Spruce Creek, from Dock at Gamble Place 21FLVEMDVC-074 Volusia County 1999–2005 28 

Spruce Creek @ Cypress Head 

Development 21FLWPB 20010737 Department 2003 6 

Spruce Creek @ Airport Rd 21FLWPB 20010738 Department 2003 6 

Spruce Creek @ 675M Upstream of 

RR Bridge 21FLCEN 27010193 Department 2005 5 

Spruce Creek @ 0.68 Miles Upstream 

of RR Bridge 21FLCEN 27010194 Department 2005 6 

Spruce Creek @ 0.87 Miles Upstream 

of RR Bridge 21FLCEN 27010195 Department 2005 5 

Spruce Creek @ 1.07 Miles Upstream 

of RR Bridge 21FLCEN 27010196 Department 2005 5 

Spruce Creek @ 1.3 Miles Upstream 

of RR Bridge 21FLCEN 27010197 Department 2005 6 

Florida Department of Environmental Protection 

27
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Table 5.3. Statistical Summary of Historical Data for Spruce Creek 

Station N Minimum Maximum Median Mean Exceedances % 

Exceedance 

Spruce Creek Center Bridge 

on U.S. Hwy 1 77 3.69 9.99 6.20 6.37 2 2.60% 

Spruce Creek West of SSC Railroad 77 3.59 8.36 5.51 5.79 2 2.60% 

Spruce Creek West of Airport Rd 78 0.07 7.99 3.23 3.29 49 62.82% 

Spruce Creek at Dock 

at Gamble Place 78 0.15 7.99 3.96 3.78 42 53.58% 

Spruce Creek 100 M Upstream from 

ICWW 1 5.1 5.1 5.10 5.10 0 0.00% 

Spruce Creek at Airport Rd 5 1.7 6.4 2.70 3.48 3 60.00% 

Spruce Creek, from W. Side of 

Center Bridge on U.S. 1 35 0.53 9.20 6.48 6.48 1 2.86% 

Spruce Creek, from Dock at 

Riverwood, W. of SCL Railroad 39 3.34 9.2 5.99 6.00 2 5.13% 

Spruce Creek, from W. Side of 

Moody Bridge on Airport Rd 35 0.04 7.09 4.16 3.86 16 45.71% 

Spruce Creek, from Dock 

at Gamble Place 28 0.01 6.42 3.56 3.45 15 53.57% 

Spruce Creek @ Cypress Head 

Development 6 6.17 7.505 6.93 6.89 0 0.00% 

Spruce Creek @ Airport Rd 6 2.53 5.88 4.05 4.10 3 50.00% 

Spruce Creek @ 675M Upstream 

of RR Bridge 5 3.68 6.5 6.05 5.34 1 20.00% 

Spruce Creek @ 0.68 Miles 

Upstream of RR Bridge 6 3.7 6.38 5.82 5.35 1 16.67% 

Spruce Creek @ 0.87 Miles 

Upstream of RR Bridge 5 3.72 6.44 5.65 5.29 1 20.00% 

Spruce Creek @ 1.07 Miles 

Upstream of RR Bridge 5 3.76 6.42 5.73 5.27 1 20.00% 

Spruce Creek @ 1.3 Miles 

Upstream of RR Bridge 6 3.7 6.54 4.73 5.06 1 16.67% 

DO concentrations are mg/L. 

Florida Department of Environmental Protection 

28
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Figure 5.2. Historical Sampling Sites in the Spruce Creek Watershed 

Florida Department of Environmental Protection 

29
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

DO VERSUS SAMPLE DATE

0

2

4

6

8

10

12

SAMPLE DATE

DISSOLVED 

OXYGEN (MG/L)

CEN 27010193 CEN 27010194 CEN 27010195 CEN 27010196 VEMDSC01 VEMDSC02

VEMDSC04 VEMDSC05 SJWMSPRCR SJWMUEC014 VEMDVC-072 VEMDVC-073

VEMDVC-074 WPB 20010737 WPB 20010738 CEN 27010197 CRITERION VEMDVC-071

Figure 5.3. Historical DO Observations for Spruce Creek 

CORR CHLA VERSUS SAMPLE DATE

0

5

10

15

20

25

30

35

40

45

50

1/1/911/1/921/1/931/1/941/1/95

1/1/96

1/1/971/1/98

1/1/99

1/1/001/1/011/1/021/1/03

1/1/04

1/1/05

1/1/06

1/1/07

SAMPLE DATE

CORR CHLA (UG/L)

VEMDSC01 VEMDSC02 VEMDSC04 VEMDSC05 SJWMSPRCR SJWMUEC014

VEMDVC-072 VEMDVC-073 VEMDVC-074 WPB 20010737 WPB 20010738 CEN 27010193

CEN 27010194 CEN 27010195 CEN 27010196 CEN 27010197

Figure 5.4. Historical Corrected Chla Observations for Spruce Creek 

Florida Department of Environmental Protection 

30
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

TN VERSUS SAMPLING DATE

0.00

0.40

0.80

1.20

1.60

2.00

2.40

2.80

3.20

3.60

4.00

1/1/911/1/921/1/931/1/941/1/95

1/1/96

1/1/97

1/1/98

1/1/991/1/00

1/1/011/1/02

1/1/03

1/1/041/1/05

1/1/061/1/07

SAMPLING DATE

TOTAL NITROGEN 

(MG/L)

VEMDSC01 VEMDSC02 VEMDSC04 VEMDSC05 SJWMSPRCR SJWMUEC014

VEMDVC-072 VEMDVC-073 VEMDVC-074 WPB 20010737 WPB 20010738 CEN 27010193

CEN 27010194 CEN 27010195 CEN 27010196 CEN 27010197

Figure 5.5. Historical TN Observations for Spruce Creek 

TP VERSUS SAMPLING DATE

0

0.2

0.4

0.6

0.8

5/7/90

9/19/911/31/93

6/15/94

10/28/95

3/11/977/24/9812/6/99

4/19/01

9/1/02

1/14/04

5/28/05

10/10/06

2/22/08

SAMPLE DATE

TOTAL 

PHOSPHORUS 

(MG/L)

VEMDSC01 VEMDSC02 VEMDSC04 VEMDSC05 SJWMSPRCR SJWMUEC014

VEMDVC-072 VEMDVC-073 VEMDVC-074 WPB 20010737 WPB 20010738 CEN 27010193

CEN 27010194 CEN 27010195 CEN 27010196 CEN 27010197

Figure 5.6. Historical TP Observations for Spruce Creek 

Florida Department of Environmental Protection 

31
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

5.1.2 TMDL Development Process 

A Spearman correlation matrix was used to assess potential relationships between DO and 

other water quality parameters (Appendix G). At an alpha (α) level of 0.05, correlations 

between DO and TP, nitrogen ammonia (NH4), and BOD were significant. Figure 5.7 illustrates 

the relationship and the regression equation between DO and TP. As discussed in the 

standards section of the report, the DO criterion for Class III marine waters allows a minimum 

concentration of 4.0 mg/L, as long as a daily average of 5.0 mg/L is maintained. Although the 

impairment decision was based on exceedances below the 4.0 mg/L minimum, the TMDL target 

for TP was selected as the level predicted to achieve a minimum DO of 5.0 mg/L in order to add 

an implicit margin of safety and ensure that both components of the criteria are met. Based on 

the regression equation, DO concentrations of 5.0 mg/L or greater would be related to TP 

concentrations less than 0.16 mg/L. For each individual observation of TP greater than 0.16 

mg/L, an individual required reduction was calculated using the following: 

[(observed value) – (0.15)] x 100

(observed value) 

After the individual results were calculated, the median of the individual values was calculated, 

which is 27 percent (Table 5.4). Use of the median was considered adequately protective since 

the calculations were based only on measurements above 0.16 mg/L and half of the 

observations were already at or below 0.16 mg/L. 

Although the correlation between DO and NH4 was significant at an alpha (α) level of 0.05 

(68 paired samples), the correlation between DO and TN was not significant (p = 0.172, 

343 paired samples). Ammonia represented 7 percent or less of the TN in 80 percent of the 

available observations. Consequently, requiring reductions in NH4 as part of the TMDL would 

have minimal effects on improving DO or reducing algal biomass. 

Figure 5.8 illustrates the relationship and the regression equation between DO and BOD. As in 

the case with TP, the TMDL considered BOD reductions necessary to achieve a DO 

concentration of 5.0 mg/L. Based on the regression equation, DO concentrations of 5.0 mg/L or 

greater would be related to BOD concentrations less than 2.17 mg/L. For each individual 

observation of BOD greater than 2.17 mg/L, an individual required reduction was calculated 

using the following: 

[(observed value) – (2.17)] x 100

(observed value) 

After the individual results were calculated, the median of the individual values was calculated, 

which is 25 percent (Table 5.5). Note there were only 27 measurements of BOD, and all of the 

samples were collected during 2005 over 7 sampling dates; where 5 stations were sampled on 

the same day for 5 of the 7 sampling dates. Additional BOD monitoring is recommended to 

augment the TMDL. 

Spruce Creek was also impaired for nutrients based on an annual chlorophyll of 12.05 μg/l in 

2003. Comparing the 2003 average with the 11 μg/L threshold suggests that less than a 9 

percent reduction in the annual average is necessary to meet the threshold. A cumulative 

frequency distribution of corrected chlorophyll can be found in Appendix E. Ninety percent of 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

the nearly 400 chlorophyll observations are less than 11.7 μg/L. The Spearman correlation 

between DO and corrected chla was negative (inverse relationship), and the linear regression 

was significant at an alpha (α) level of 0.05. A 27 percent reduction of total phosphorus to 

Spruce Creek will result in lower algal biomass and is believed to be sufficient to result in an 

annual average chla concentration below the 11 μg/L threshold. 

Figure 5.7. Relationship Between DO and TP Observations for 

Spruce Creek 

DISSOLVED OXYGEN VERSUS TP

y = -8.9405x + 6.389

R2

 = 0.1785

0

2

4

6

8

10

12

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

TOTAL PHOSPHORUS (MG/L)

DISSOLVED OXYGEN 

(MG/L)

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

DISSOLVED OXYGEN VERSUS BOD

y = -0.8918x + 6.9383

R2

 = 0.6848

0

1

2

3

4

5

6

7

012345

BOD (MG/L)

DISSOLVED OXYGEN 

(MG/L)

Figure 5.8. Relationship Between DO and BOD Observations for 

Spruce Creek 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Table 5.4. Calculation of TP Reductions for the DO TMDL for Spruce 

Creek 

Sample Date Station Observed TP Value 

(mg/L) % Reduction 

1/6/1992 VEMDSC05 0.21 23.81% 

3/2/1992 VEMDSC04 0.19 15.79% 

3/2/1992 VEMDSC05 0.22 27.27% 

4/6/1992 VEMDSC04 0.18 11.11% 

4/6/1992 VEMDSC05 0.27 40.74% 

5/4/1992 VEMDSC02 0.22 27.27% 

5/4/1992 VEMDSC04 0.24 33.33% 

5/4/1992 VEMDSC05 0.25 36.00% 

6/1/1992 VEMDSC05 0.25 36.00% 

7/6/1992 VEMDSC02 0.19 15.79% 

7/6/1992 VEMDSC01 0.19 15.79% 

7/6/1992 VEMDSC04 0.22 27.27% 

8/3/1992 VEMDSC01 0.26 38.46% 

8/3/1992 VEMDSC05 0.27 40.74% 

8/3/1992 VEMDSC02 0.35 54.29% 

9/9/1992 VEMDSC02 0.17 5.88% 

9/9/1992 VEMDSC02 0.17 5.88% 

10/5/1992 VEMDSC05 0.22 27.27% 

10/5/1992 VEMDSC01 0.28 42.86% 

10/5/1992 VEMDSC02 0.33 51.52% 

1/4/1993 VEMDSC04 0.18 11.11% 

1/4/1993 VEMDSC02 0.2 20.00% 

5/4/1993 VEMDSC04 0.69 76.81% 

6/8/1993 VEMDSC02 0.21 23.81% 

6/8/1993 VEMDSC04 0.3 46.67% 

6/8/1993 VEMDSC05 0.3 46.67% 

7/7/1993 VEMDSC04 0.23 30.43% 

7/7/1993 VEMDSC05 0.26 38.46% 

7/7/1993 VEMDSC01 0.27 40.74% 

8/2/1993 VEMDSC02 0.18 11.11% 

8/2/1993 VEMDSC05 0.28 42.86% 

8/2/1993 VEMDSC04 0.4 60.00% 

9/8/1993 VEMDSC04 0.66 75.76% 

10/4/1993 VEMDSC02 0.17 5.88% 

10/4/1993 VEMDSC05 0.22 27.27% 

10/4/1993 VEMDSC04 0.24 33.33% 

11/1/1993 VEMDSC05 0.23 30.43% 

1/3/1994 VEMDSC04 0.3 46.67% 

1/3/1994 VEMDSC05 0.375 57.33% 

4/4/1994 VEMDSC05 0.17 5.88% 

4/4/1994 VEMDSC04 0.22 27.27% 

5/2/1994 VEMDSC01 0.17 5.88% 

5/2/1994 VEMDSC02 0.245 34.69% 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Observed TP Value Sample Date Station % Reduction (mg/L) 

5/2/1994 VEMDSC04 0.27 40.74% 

5/2/1994 VEMDSC05 0.36 55.56% 

6/6/1994 VEMDSC02 0.205 21.95% 

6/6/1994 VEMDSC05 0.28 42.86% 

6/6/1994 VEMDSC04 0.38 57.89% 

7/6/1994 VEMDSC04 0.17 5.88% 

7/6/1994 VEMDSC02 0.23 30.43% 

8/1/1994 VEMDSC02 0.265 39.62% 

8/1/1994 VEMDSC05 0.53 69.81% 

8/1/1994 VEMDSC04 0.61 73.77% 

9/6/1994 VEMDSC05 0.19 15.79% 

9/6/1994 VEMDSC04 0.22 27.27% 

10/3/1994 VEMDSC04 0.19 15.79% 

10/3/1994 VEMDSC05 0.22 27.27% 

10/3/1994 VEMDSC02 0.29 44.83% 

11/1/1994 VEMDSC01 0.19 15.79% 

11/1/1994 VEMDSC02 0.25 36.00% 

11/1/1994 VEMDSC05 0.42 61.90% 

11/1/1994 VEMDSC04 0.625 74.40% 

12/5/1994 VEMDSC04 0.17 5.88% 

1/9/1995 VEMDSC04 0.2 20.00% 

5/1/1995 VEMDSC02 0.22 27.27% 

5/1/1995 VEMDSC01 0.23 30.43% 

5/1/1995 VEMDSC04 0.34 52.94% 

6/5/1995 VEMDSC02 0.2 20.00% 

6/5/1995 VEMDSC05 0.26 38.46% 

6/5/1995 VEMDSC04 0.275 41.82% 

6/5/1995 VEMDSC01 0.32 50.00% 

7/10/1995 VEMDSC02 0.2 20.00% 

7/10/1995 VEMDSC04 0.32 50.00% 

8/7/1995 VEMDSC05 0.2 20.00% 

8/7/1995 VEMDSC02 0.24 33.33% 

8/7/1995 VEMDSC01 0.25 36.00% 

9/5/1995 VEMDSC01 0.2 20.00% 

9/5/1995 VEMDSC05 0.2 20.00% 

9/5/1995 VEMDSC02 0.22 27.27% 

9/5/1995 VEMDSC04 0.255 37.25% 

10/2/1995 VEMDSC04 0.17 5.88% 

10/2/1995 VEMDSC01 0.19 15.79% 

10/2/1995 VEMDSC02 0.23 30.43% 

11/6/1995 VEMDSC02 0.25 36.00% 

11/6/1995 VEMDSC01 0.3 46.67% 

2/5/1996 VEMDSC04 0.24 33.33% 

3/4/1996 VEMDSC01 0.2 20.00% 

3/4/1996 VEMDSC04 0.41 60.98% 

4/1/1996 VEMDSC05 0.165 3.03% 

4/1/1996 VEMDSC04 0.22 27.27% 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Observed TP Value Sample Date Station % Reduction (mg/L) 

4/1/1996 VEMDSC02 0.24 33.33% 

4/1/1996 VEMDSC01 0.34 52.94% 

5/6/1996 VEMDSC04 0.175 8.57% 

6/3/1996 VEMDSC01 0.23 30.43% 

6/3/1996 VEMDSC02 0.33 51.52% 

7/8/1996 VEMDSC01 0.2 20.00% 

7/8/1996 VEMDSC05 0.235 31.91% 

7/8/1996 VEMDSC04 0.34 52.94% 

7/8/1996 VEMDSC02 0.4 60.00% 

8/5/1996 VEMDSC04 0.17 5.88% 

9/3/1996 VEMDSC01 0.17 5.88% 

9/3/1996 VEMDSC04 0.26 38.46% 

10/7/1996 VEMDSC01 0.23 30.43% 

10/7/1996 VEMDSC02 0.29 44.83% 

10/7/1996 VEMDSC05 0.43 62.79% 

10/7/1996 VEMDSC04 0.53 69.81% 

1/6/1997 VEMDSC05 0.2 20.00% 

1/6/1997 VEMDSC01 0.22 27.27% 

2/3/1997 VEMDSC04 0.2 20.00% 

3/3/1997 VEMDSC01 0.17 5.88% 

4/7/1997 VEMDSC02 0.17 5.88% 

4/7/1997 VEMDSC04 0.17 5.88% 

4/7/1997 VEMDSC05 0.2 20.00% 

6/2/1997 VEMDSC05 0.17 5.88% 

6/2/1997 VEMDSC04 0.19 15.79% 

7/7/1997 VEMDSC04 0.21 23.81% 

7/7/1997 VEMDSC05 0.35 54.29% 

8/4/1997 VEMDSC05 0.21 23.81% 

8/4/1997 VEMDSC04 0.21 23.81% 

9/8/1997 VEMDSC05 0.18 11.11% 

9/8/1997 VEMDSC02 0.21 23.81% 

9/8/1997 VEMDSC04 0.22 27.27% 

10/6/1997 VEMDSC04 0.19 15.79% 

11/3/1997 VEMDSC02 0.26 38.46% 

11/3/1997 VEMDSC05 0.27 40.74% 

11/3/1997 VEMDSC04 0.44 63.64% 

3/2/1998 VEMDSC02 0.17 5.88% 

3/2/1998 VEMDSC04 0.2 20.00% 

5/4/1998 VEMDSC05 0.19 15.79% 

6/1/1998 VEMDSC04 0.17 5.88% 

6/1/1998 VEMDSC05 0.51 68.63% 

7/6/1998 VEMDSC01 0.175 8.57% 

7/6/1998 VEMDSC02 0.18 11.11% 

7/6/1998 VEMDSC04 0.43 62.79% 

7/6/1998 VEMDSC05 0.64 75.00% 

8/3/1998 VEMDSC02 0.19 15.79% 

8/3/1998 VEMDSC05 0.44 63.64% 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Sample Date Station Observed TP Value 

(mg/L) % Reduction 

8/3/1998 VEMDSC04 0.51 68.63% 

9/8/1998 VEMDSC02 0.165 3.03% 

9/8/1998 VEMDSC05 0.24 33.33% 

9/8/1998 VEMDSC04 0.35 54.29% 

10/6/1998 VEMDSC02 0.18 11.11% 

10/6/1998 VEMDSC05 0.23 30.43% 

10/6/1998 VEMDSC04 0.24 33.33% 

11/2/1998 VEMDSC04 0.17 5.88% 

11/2/1998 VEMDSC05 0.17 5.88% 

12/2/1998 VEMDSC05 0.18 11.11% 

2/1/1999 VEMDVC-072 0.17 5.88% 

2/1/1999 VEMDVC-074 0.18 11.11% 

3/1/1999 VEMDVC-072 0.4 60.00% 

4/5/1999 VEMDVC-074 0.24 33.33% 

5/3/1999 VEMDVC-071 0.19 15.79% 

5/3/1999 VEMDVC-072 0.19 15.79% 

5/3/1999 VEMDVC-073 0.21 23.81% 

5/3/1999 VEMDVC-074 0.3 46.67% 

6/7/1999 VEMDVC-072 0.17 5.88% 

6/7/1999 VEMDVC-074 0.29 44.83% 

6/7/1999 VEMDVC-073 0.3 46.67% 

7/7/1999 VEMDVC-073 0.18 11.11% 

7/7/1999 VEMDVC-071 0.19 15.79% 

7/7/1999 VEMDVC-072 0.21 23.81% 

8/2/1999 VEMDVC-072 0.18 11.11% 

8/2/1999 VEMDVC-073 0.43 62.79% 

9/7/1999 VEMDVC-074 0.25 36.00% 

10/4/1999 VEMDVC-071 0.2 20.00% 

10/4/1999 VEMDVC-072 0.28 42.86% 

10/4/1999 VEMDVC-073 0.32 50.00% 

11/1/1999 VEMDVC-072 0.19 15.79% 

11/1/1999 VEMDVC-071 0.19 15.79% 

4/3/2000 VEMDVC-074 0.19 15.79% 

4/3/2000 VEMDVC-071 0.2 20.00% 

4/3/2000 VEMDVC-073 0.22 27.27% 

4/3/2000 VEMDVC-072 0.25 36.00% 

7/10/2000 VEMDVC-074 0.24 33.33% 

7/10/2000 VEMDVC-073 0.24 33.33% 

10/2/2000 VEMDVC-073 0.2 20.00% 

2/5/2001 VEMDVC-073 0.25 36.00% 

2/5/2001 VEMDVC-074 0.41 60.98% 

8/6/2001 VEMDVC-072 0.22 27.27% 

8/6/2001 VEMDVC-071 0.22 27.27% 

8/6/2001 VEMDVC-073 0.31 48.39% 

8/6/2001 VEMDVC-074 0.31 48.39% 

11/5/2001 VEMDVC-071 0.19 15.79% 

9/9/2002 VEMDVC-071 0.2 20.00% 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Observed TP Value 

(mg/L) Sample Date Station % Reduction 

5/5/2003 VEMDVC-071 0.18 11.11% 

8/4/2003 VEMDVC-071 0.19 15.79% 

8/13/2003 WPB 20010738 0.236 32.20% 

8/26/2003 WPB 20010738 0.325 50.77% 

10/9/2003 WPB 20010738 0.195 17.95% 

6/13/2005 CEN 27010195 0.27 40.74% 

6/13/2005 CEN 27010194 0.29 44.83% 

6/13/2005 CEN 27010193 0.315 49.21% 

8/8/2005 CEN 27010195 0.31 48.39% 

8/8/2005 CEN 27010193 0.35 54.29% 

8/8/2005 CEN 27010194 0.36 55.56% 

4/3/2006 VEMDVC-071 0.22 27.27% 

10/3/2006 VEMDVC-073 0.21 23.81% 

MEDIAN: 27.27% 

Table 5.5. Calculation of BOD Reductions for the DO TMDL for 

Spruce Creek 

Sample Date Station 

Observed BOD 

value 

(mg/L) 

% Reduction 

8/8/2005 CEN 27010194 2.3 5.65 

8/8/2005 CEN 27010193 2.4 9.58 

8/8/2005 CEN 27010195 2.5 13.20 

4/5/2005 CEN 27010194 2.6 16.54 

8/8/2005 CEN 27010196 2.8 22.50 

8/8/2005 CEN 27010197 2.9 25.17 

6/13/2005 CEN 27010196 3 27.67 

6/13/2005 CEN 27010197 3 27.67 

6/13/2005 CEN 27010193 3.1 30.00 

6/13/2005 CEN 27010195 3.5 38.00 

6/13/2005 CEN 27010194 4.2 48.33 

MEDIAN: 25.17 

5.1.3 Critical Conditions/Seasonality 

A nonparametric test (Kruskal-Wallis) was applied to the DO, DO saturation (DOSAT), corrected 

chla, TN, and TP datasets to determine whether there were significant differences among 

months or seasons. At an alpha (α) level of 0.05, there were significant differences among 

seasons or months for all the parameters (Appendices C and D). As seen in Table 5.6, all 

seasons had at least a 21 percent exceedance rate. All months had exceedance rates of at 

least 11 percent, while June, July, and September had the highest exceedance rates. 

Consequently, the percent reductions were calculated throughout the year and covered all 

months and seasons. 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Rainfall records for Daytona Beach International Airport (Appendices F and I) were used to 

determine rainfall amounts associated with individual sampling dates. Rainfall recorded on the 

day of sampling (PRECIP) and the cumulative total for the day of and the previous two days 

(RAINDAY3) were paired with the respective DO observation. The simple correlations (r values 

in the Spearman correlation table) between both DO and the PRECIP and RAINDAY3 rainfall 

totals were negative (inverse relationship); however, they were not significant at an alpha (α) 

level of 0.05. 

Table 5.6. Monthly and Seasonal Exceedance Rates for DO 

# of Observations # of Exceedances % Exceedance 

Month 

January 36 10 27.8% 

February 45 8 17.8% 

March 33 6 18.2% 

April 36 4 11.1% 

May 30 9 23.3% 

June 43 21 48.8% 

July 32 14 43.8% 

August 34 11 32.3% 

September 24 12 50.0% 

October 36 10 27.8% 

November 36 8 22.2% 

December 38 11 28.9% 

# of Observations # of Exceedances % Exceedance 

Season 

Winter 114 24 21.0% 

Spring 109 34 31.2% 

Summer 90 37 41.1% 

Fall 110 29 26.4% 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Chapter 6: DETERMINATION OF THE TMDL 

6.1 Expression and Allocation of the TMDL 

The objective of a TMDL is to provide a basis for allocating acceptable loads among all of the 

known pollutant sources in a watershed so that appropriate control measures can be 

implemented and water quality standards achieved. A TMDL is expressed as the sum of all 

point source loads (Wasteload Allocations, or WLAs), nonpoint source loads (Load Allocations, 

or LAs), and an appropriate margin of safety (MOS), which takes into account any uncertainty 

concerning the relationship between effluent limitations and water quality: 

TMDL = ∑ WLAs + ∑ LAs + MOS

As discussed earlier, the WLA is broken out into separate subcategories for wastewater 

discharges and stormwater discharges regulated under the NPDES Program: 

TMDL ≅ ∑ WLAswastewater + ∑ WLAsNPDES Stormwater + ∑ LAs + MOS 

It should be noted that the various components of the revised TMDL equation may not sum up 

to the value of the TMDL because (a) the WLA for NPDES stormwater is typically based on the 

percent reduction needed for nonpoint sources and is also accounted for within the LA, and (b) 

TMDL components can be expressed in different terms (for example, the WLA for stormwater is 

typically expressed as a percent reduction, and the WLA for wastewater is typically expressed 

as mass per day). 

WLAs for stormwater discharges are typically expressed as “percent reduction” because it is 

very difficult to quantify the loads from MS4s (given the numerous discharge points) and to 

distinguish loads from MS4s from other nonpoint sources (given the nature of stormwater 

transport). The permitting of stormwater discharges also differs from the permitting of most 

wastewater point sources. Because stormwater discharges cannot be centrally collected, 

monitored, and treated, they are not subject to the same types of effluent limitations as 

wastewater facilities, and instead are required to meet a performance standard of providing 

treatment to the “maximum extent practical” through the implementation of BMPs. 

This approach is consistent with federal regulations (40 CFR § 130.2[I]), which state that TMDLs 

can be expressed in terms of mass per time (e.g., pounds per day), toxicity, or other 

appropriate measure. TMDLs for Spruce Creek are expressed in terms of a percent reduction 

in total phosphorus, to meet both the DO and nutrient criteria (Table 6.1).

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Table 6.1. TMDL Components for Spruce Creek 

WLA 

WBID Parameter TMDL 

(mg/L) Wastewater 

(mg/L) 

NPDES 

Stormwater 

(% Reduction)1

LA 

(% 

Reduction)1 MOS 

2674A TP 0.16 N/A 27% 27% Implicit 

2674A BOD 2.17 NA 25% 25% Implicit 

1

 As the TMDL represents a percent reduction, it also complies with EPA requirements to express the TMDL on a daily basis. 

6.2 Load Allocation 

A TP reduction of 27 percent and a 25 percent reduction in BOD are required from nonpoint 

sources. It should be noted that the load allocation includes loading from stormwater 

discharges that are not part of the NPDES Stormwater Program. 

6.3 Wasteload Allocation 

6.3.1 NPDES Wastewater Discharges 

There are currently no permitted NPDES discharges in the Spruce Creek watershed; however, 

any future discharge permits issued in the watershed will also be required to meet the state’s 

Class III criterion for DO and contain appropriate discharge limitations on phosphorus that will 

comply with the TMDL as well as existing state requirements related to discharges to OFWs. 

 6.3.2 NPDES Stormwater Discharges 

Volusia County (FLR04E033), Port Orange (FLR04E014), Ponce Inlet (FLR04E071), and New 

Smyrna Beach (FLR04E035) have Phase II MS4 permits that may include portions of the 

Spruce Creek watershed and would be responsible for a 27 percent reduction in current 

anthropogenic TP loading and a 25 percent reduction in current anthropogenic BOD loading. It 

should be noted that any MS4 permittee is only responsible for reducing the loads associated 

with stormwater outfalls that it owns or otherwise has responsible control over, and it is not 

responsible for reducing other nonpoint source loads in its jurisdiction. 

6.4 Margin of Safety 

Consistent with the recommendations of the Allocation Technical Advisory Committee 

(Department, 2001), an implicit MOS was used in the development of this TMDL. An MOS was 

included in the TMDL by not allowing any exceedances of the state criteria, even though 

intermittent natural exceedances of the criteria would be expected and would be taken into 

account when determining impairment. Additionally, the TMDL calculated for DO was based on 

meeting a DO of 5.0 mg/L, rather than the marine minimum of 4.0 mg/L. 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Chapter 7: NEXT STEPS: IMPLEMENTATION PLAN 

DEVELOPMENT AND BEYOND 

7.1 Basin Management Action Plan 

Following the adoption of this TMDL by rule, the next step in the TMDL process is to develop an 

implementation plan for the TMDL, referred to as the BMAP. This document will be developed 

over the next year in cooperation with local stakeholders, who will attempt to reach consensus 

on detailed allocations and on how load reductions will be accomplished. The BMAP will 

include, among other things: 

• Appropriate load reduction allocations among the affected parties, 

• A description of the load reduction activities to be undertaken, including structural 

projects, nonstructural BMPs, and public education and outreach, 

• A description of further research, data collection, or source identification needed in order 

to achieve the TMDL, 

• Timetables for implementation, 

• Confirmed and potential funding mechanisms, 

• Any applicable signed agreement(s), 

• Local ordinances defining actions to be taken or prohibited, 

• Any applicable local water quality standards, permits, or load limitation agreements, 

• Milestones for implementation and water quality improvement, and 

• Implementation tracking, water quality monitoring, and follow-up measures. 

An assessment of progress toward the BMAP milestones will be conducted every five years, 

and revisions to the plan will be made as appropriate, in cooperation with basin stakeholders. 

Earlier in the document a Spruce Creek/Rose Bay Watershed Master Plan (Volusia County, 

1996) was referenced, along with current plans for the county to update the document. 

Implementation measures that reduce stormwater impacts to both water quantity and water 

quality in the Spruce Creek watershed should be recognized in the BMAP. In addition, as noted 

in Chapter 5, the relationship developed between BOD and DO was based on measurements 

collected in a single year. Additional monitoring as part of the BMAP could improve the 

understanding of sources of BOD from the contributing watershed and impacts on DO. Chapter 

4 summarized potential contributions of TN and TP from various sources in WBID 2674A and 

the upstream portion of Spruce Creek (WBID 2674). Elements of the BMAP can also focus 

efforts to better quantify the actual loads from the sources identified as well as evaluate 

contributions from the drainage area outside the two Spruce Creek WBIDs. As noted in Chapter 

5, the USGS gage located on Spruce Creek near the railroad bridge (Gage 02248053) had an 

estimated drainage area of 60.7 square miles and was tidally influenced. 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Florida Department of Environmental Protection 

44

References

Florida Administrative Code. Rule 62-302, Surface water quality standards.

———. Rule 62-303, Identification of impaired surface waters.

Florida Department of Environmental Protection. February 2001. A report to the Governor and 

the Legislature on the allocation of Total Maximum Daily Loads in Florida. Tallahassee, 

Florida: Bureau of Watershed Management. 

———. 2005. Upper East Coast Basin status report. Tallahassee, Florida. Available: 

http://www.dep.state.fl.us/water/basin411/uppereast/status.htm. 

Florida Department of Health Website. 2006. Available: http://www.doh.state.fl.us/. 

———. 2006. Available: 

http://www.doh.state.fl.us/environment/OSTDS/statistics/newInstallations.pdf. 

———. 2006. Available: http://www.doh.state.fl.us/environment/OSTDS/statistics/repairs.pdf. 

Florida Watershed Restoration Act. Chapter 99-223, Laws of Florida. 

Harper, H.H., and D.M. Baker. 2003. Evaluation of alternative stormwater regulations for 

southwest Florida. Orlando, Florida: Environmental Research & Design, Inc. 

U. S. Census Bureau Website. 2000. Available: http://www.census.gov/. 

U. S. Environmental Protection Agency. 1999. Protocol for developing nutrient TMDLs. First 

Edition. EPA 841–B–99–007. 

———. June 2001. BASINS Version 3.0 user manual. Office of Water. Available: 

http://www.epa.gov/waterscience/basins/bsnsdocs.html. 

U. S. Environmental Protection Agency Region 4. 2002. Estimating water quality loadings from 

MS4 areas.

Volusia County. April 1996. Spruce Creek/Rose Bay OFW watershed master plan. Prepared 

by Marshall, Provost & Associates. 
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Appendices 

Appendix A: Background Information on Federal and State Stormwater 

Programs 

In 1982, Florida became the first state in the country to implement statewide regulations to 

address the issue of nonpoint source pollution by requiring new development and redevelopment 

to treat stormwater before it is discharged. The Stormwater Rule, as authorized in Chapter 403, 

F.S., was established as a technology-based program that relies on the implementation of BMPs 

that are designed to achieve a specific level of treatment (i.e., performance standards) as set 

forth in Rule 62-40, F.A.C. In 1994, the Department’s stormwater treatment requirements were 

integrated with the stormwater flood control requirements of the water management districts, 

along with wetland protection requirements, into the Environmental Resource Permit regulations. 

Rule 62-40 also requires the state’s water management districts to establish stormwater pollutant 

load reduction goals (PLRGs) and adopt them as part of a Surface Water Improvement and 

Management (SWIM) plan, other watershed plan, or rule. Stormwater PLRGs are a major 

component of the load allocation part of a TMDL. To date, stormwater PLRGs have been 

established for Tampa Bay, Lake Thonotosassa, the Winter Haven Chain of Lakes, the 

Everglades, Lake Okeechobee, and Lake Apopka. 

In 1987, the U.S. Congress established Section 402(p) as part of the federal Clean Water Act 

Reauthorization. This section of the law amended the scope of the federal NPDES permitting 

program to designate certain stormwater discharges as “point sources” of pollution. The EPA 

promulgated regulations and began implementing the Phase I NPDES stormwater program in 

1990. These stormwater discharges include certain discharges that are associated with industrial 

activities designated by specific standard industrial classification (SIC) codes, construction sites 

disturbing 5 or more acres of land, and master drainage systems of local governments with a 

population above 100,000, which are better known as MS4s. However, because the master 

drainage systems of most local governments in Florida are interconnected, the EPA implemented 

Phase I of the MS4 permitting program on a countywide basis, which brought in all cities 

(incorporated areas), Chapter 298 urban water control districts, and the Florida Department of 

Transportation throughout the 15 counties meeting the population criteria. The Department 

received authorization to implement the NPDES stormwater program in 2000. 

An important difference between the federal NPDES and the state’s stormwater/environmental 

resource permitting programs is that the NPDES Program covers both new and existing 

discharges, while the state’s program focus on new discharges only. Additionally, Phase II of the 

NPDES Program, implemented in 2003, expands the need for these permits to construction sites 

between 1 and 5 acres, and to local governments with as few as 1,000 people. While these 

urban stormwater discharges are now technically referred to as “point sources” for the purpose of 

regulation, they are still diffuse sources of pollution that cannot be easily collected and treated by 

a central treatment facility, as are other point sources of pollution such as domestic and industrial 

wastewater discharges. It should be noted that all MS4 permits issued in Florida include a 

reopener clause that allows permit revisions to implement TMDLs when the implementation plan 

is formally adopted. 

Florida Department of Environmental Protection 

45
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Appendix B: Historical DO, Corrected Chla, TN, and TP Observations 

in Spruce Creek, 1991–2006 

Station Sample Date DO 

(mg/L) 

DOSAT 

(%) 

Corr Chla 

(μg/L) 

TN 

(mg/L) 

TP 

(mg/L) 

VEMDSC04 12/2/1991 1.3 14.1304 25.8 0.92 0.13 

VEMDSC05 12/2/1991 1.8 20.4545 1 0.91 0.14 

VEMDSC02 12/2/1991 6.8 80 7.8 1.18 0.13 

VEMDSC01 12/2/1991 7.33 87.2619 8.7 1.14 0.13 

VEMDSC05 1/6/1992 0.37 3.9697 0.63 0.21 

VEMDSC04 1/6/1992 3.08 31.7525 0.8 0.14 

VEMDSC02 1/6/1992 8.01 78.5294 2.01 0.05 

VEMDSC01 1/6/1992 8.37 83.7 1 0.09 

VEMDSC05 2/3/1992 1.78 18.7368 4.7 2.76 0.15 

VEMDSC04 2/3/1992 2.79 28.7628 27.6 1.12 0.14 

VEMDSC02 2/3/1992 7.94 79.4 1.8 0.08 

VEMDSC01 2/3/1992 9.31 93.1 1 1.63 0.07 

VEMDSC04 3/2/1992 2.91 30.6315 1 1.41 0.19 

VEMDSC05 3/2/1992 5.15 53.0928 1 1.03 0.22 

VEMDSC02 3/2/1992 8.09 86.0638 2 1.4 0.12 

VEMDSC01 3/2/1992 9.77 103.936 1.6 2.22 0.13 

VEMDSC05 4/6/1992 0.2 2.22222 7.1 0.27 

VEMDSC04 4/6/1992 2.58 28.6666 3.5 1.14 0.18 

VEMDSC01 4/6/1992 6.98 74.2553 3 0.09 

VEMDSC02 4/6/1992 7.04 74.8936 5.9 0.12 

VEMDSC05 5/4/1992 0.3 3.44827 1.23 0.25 

VEMDSC04 5/4/1992 1.8 21.1765 2.58 0.24 

VEMDSC02 5/4/1992 5.9 69.4117 0.22 

VEMDSC01 5/4/1992 6.2 71.2643 0.15 

SJWMSPRCR 5/28/1992 5.1 75.9018 0.612 0.097 

VEMDSC05 6/1/1992 0.19 2.2619 6.9 0.91 0.25 

VEMDSC04 6/1/1992 1.21 14.9383 11.8 1.15 0.16 

VEMDSC02 6/1/1992 5.2 65.8228 11.3 0.14 

VEMDSC01 6/1/1992 6.06 76.7088 4.7 0.07 

VEMDSC05 7/6/1992 0.15 1.85185 1.9 

VEMDSC04 7/6/1992 2.06 25.4321 4.9 1.58 0.22 

VEMDSC02 7/6/1992 4.13 55.0666 9.5 1.21 0.19 

VEMDSC01 7/6/1992 5.06 68.3783 9.2 1.29 0.19 

SJWMUEC014 7/22/1992 1.7 20.9876 25.527 

VEMDSC04 8/3/1992 0.14 1.8421 10.6 

VEMDSC05 8/3/1992 3.03 36.0714 1.1 1.33 0.27 

VEMDSC01 8/3/1992 4.14 53.0769 5.6 1.86 0.26 

Florida Department of Environmental Protection 

46
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

DO DOSAT Corr Chla TN TP Station Sample Date 

Florida Department of Environmental Protection 

47

(mg/L) (%) (μg/L) (mg/L) (mg/L) 

VEMDSC02 8/3/1992 5.4 71.0526 11.7 0.35 

VEMDSC04 9/9/1992 3.07 36.5476 1.7 1.38 0.1 

VEMDSC04 9/9/1992 3.1 38 1.7 1.36 0.1 

VEMDSC05 9/9/1992 4.25 50.5952 1 1.51 0.06 

VEMDSC05 9/9/1992 4.3 52.1 0.1 1.56 0.06 

VEMDSC02 9/9/1992 4.18 52.9114 5.2 2.45 0.17 

VEMDSC02 9/9/1992 4.2 59.5 5.2 2.45 0.17 

VEMDSC01 9/9/1992 4.95 63.4615 5.6 3.19 0.15 

VEMDSC01 9/9/1992 5 74.1 5.6 3.19 0.15 

VEMDSC05 10/5/1992 4.92 56.5517 1 0.22 

VEMDSC04 10/5/1992 5.07 59.647 1.4 1.43 

VEMDSC02 10/5/1992 5.43 63.8823 1.4 1.45 0.33 

VEMDSC01 10/5/1992 5.54 65.9523 3.2 1.49 0.28 

VEMDSC04 11/2/1992 3.05 33.8889 1.1 1.1 0.13 

VEMDSC05 11/2/1992 4.26 47.3333 1 1.24 0.06 

VEMDSC02 11/2/1992 5.59 66.5476 4 0.13 

VEMDSC01 11/2/1992 5.94 70.7142 4 1.35 0.14 

VEMDSC04 12/7/1992 5.89 57.7451 

VEMDSC05 12/7/1992 6.25 61.2745 

VEMDSC02 12/7/1992 7.67 79.0721 

VEMDSC01 12/7/1992 8.27 87.0526 

VEMDSC05 1/4/1993 2.77 30.10865 1 1.06 0.135 

VEMDSC04 1/4/1993 4.41 47.9348 3.2 0.83 0.18 

VEMDSC02 1/4/1993 7.36 81.7777 4.3 0.56 0.2 

VEMDSC01 1/4/1993 7.54 83.7777 3.1 0.8 0.16 

VEMDSC05 2/1/1993 6.51 62.59615 1 1.3335 0.031 

VEMDSC04 2/1/1993 6.92 69.2 1 1.415 0.063 

VEMDSC02 2/1/1993 7.41 76.3917 1 1.356 0.113 

VEMDSC01 2/1/1993 8.1 81 1.6 1.171 0.12 

VEMDSC04 3/1/1993 7.06 66.6037 1 1.11 0.1 

VEMDSC02 3/1/1993 7.21 70.6862 1.9 1.236 0.11 

VEMDSC05 3/1/1993 7.51 72.2115 1 1.125 0.09 

VEMDSC01 3/1/1993 8.75 85.7843 1.4 1.22 0.1 

VEMDSC04 4/5/1993 4.58 48.7234 1.42 0.132 

VEMDSC02 4/5/1993 5.86 65.1111 0.688 0.149 

VEMDSC01 4/5/1993 6.87 76.3333 0.463 0.129 

VEMDSC05 4/5/1993 7.66 81.48935 1.4015 0.102 

VEMDSC04 5/4/1993 4.58 48.7234 11 1.855 0.69 

VEMDSC02 5/4/1993 5.86 65.1111 3.8 1.252 0.12 

VEMDSC01 5/4/1993 6.87 76.3333 3.6 1.213 0.1 

VEMDSC05 5/4/1993 7.66 81.48935 44.2 0.963 0.125 
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

DO DOSAT Corr Chla TN TP Station Sample Date 

Florida Department of Environmental Protection 

48

(mg/L) (%) (μg/L) (mg/L) (mg/L) 

SJWMUEC014 5/19/1993 6.4 81.1523 6.148 

VEMDSC04 6/8/1993 0.54 6.92307 7 0.969 0.3 

VEMDSC05 6/8/1993 3.51 42.80485 9.25 1.058 0.3 

VEMDSC01 6/8/1993 4.43 56.7948 3.5 1.972 0.14 

VEMDSC02 6/8/1993 4.63 60.921 6.2 1.441 0.21 

SJWMUEC014 6/16/1993 2.7 36.0269 2.94 0.567 

VEMDSC04 7/7/1993 0.22 3.2 10.9 0.777 0.23 

VEMDSC05 7/7/1993 0.31 4.1 19.5 1.014 0.26 

VEMDSC01 7/7/1993 3.69 58.7 3.5 1.678 0.27 

VEMDSC02 7/7/1993 4.57 70 8.9 1.176 0.16 

SJWMUEC014 7/14/1993 4.4 57.7913 21.5 1.16 

VEMDSC04 8/2/1993 2.53 33.5 81.6 1.292 0.4 

VEMDSC05 8/2/1993 3.79 47.1 2.3 1.085 0.28 

VEMDSC02 8/2/1993 4.51 69.7 8.6 1.381 0.18 

VEMDSC01 8/2/1993 4.66 74.3 4.5 2.055 0.11 

SJWMUEC014 8/25/1993 2.2 27.7413 1.189 

VEMDSC04 9/8/1993 0.22 3 5.9 0.686 0.66 

VEMDSC05 9/8/1993 3.14 38.2 3.3 0.797 

VEMDSC01 9/8/1993 4.03 61.1 6.6 0.504 0.08 

VEMDSC02 9/8/1993 4.33 62.7 13.4 0.724 0.078 

VEMDSC04 10/4/1993 0.44 5.9 36.3 1.186 0.24 

VEMDSC05 10/4/1993 2.52 29.7 2.7 0.832 0.22 

VEMDSC02 10/4/1993 5.28 76.8 5.5 1.198 0.17 

VEMDSC01 10/4/1993 5.87 88.5 5.2 1.632 0.12 

VEMDSC04 11/1/1993 1.33 16.4 0.4 0.857 0.16 

VEMDSC05 11/1/1993 4.54 46.5 0.3 1.342 0.23 

VEMDSC02 11/1/1993 6.22 73.7 8.6 1.333 0.13 

VEMDSC01 11/1/1993 6.54 85.4 3.7 1.206 0.09 

VEMDSC04 12/6/1993 1.34 15.8 12.7 0.936 0.13 

VEMDSC05 12/6/1993 1.59 18.5 0.5 0.805 0.15 

VEMDSC02 12/6/1993 6.05 73.7 7.9 1.161 0.1 

VEMDSC01 12/6/1993 6.53 83.7 1.9 1.411 0.07 

VEMDSC04 1/3/1994 3.66 36.6 2.12 1.269 0.3 

VEMDSC05 1/3/1994 5.565 57.3711 2.54 1.3375 0.375 

VEMDSC01 1/3/1994 7.52 77.5257 2.08 1.281 0.07 

VEMDSC02 1/3/1994 8.28 85.3608 26.38 1.002 0.1 

VEMDSC04 2/7/1994 5.41 54.1 1 1.76 0.15 

VEMDSC05 2/7/1994 5.61 57.835 1 1.672 0.13 

VEMDSC02 2/7/1994 6.27 66.70205 2.36 1.836 0.14 

VEMDSC01 2/7/1994 7.35 77.3684 3.05 1.845 0.11 

VEMDSC01 3/7/1994 3.33 1.628 0.08 
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

DO DOSAT Corr Chla TN TP Station Sample Date 

Florida Department of Environmental Protection 

49

(mg/L) (%) (μg/L) (mg/L) (mg/L) 

VEMDSC02 3/7/1994 2.345 1.677 0.12 

VEMDSC04 3/7/1994 1 1.675 0.09 

VEMDSC05 3/7/1994 1 1.763 0.06 

VEMDSC05 4/4/1994 3.02 32.5 0.5 1.048 0.17 

VEMDSC04 4/4/1994 4.56 52.8 5.4 1.346 0.22 

VEMDSC02 4/4/1994 5.62 72.6 2.3 1.883 0.12 

VEMDSC01 4/4/1994 5.96 78.4 2 2.071 0.11 

VEMDSC01 5/2/1994 3.19 1.483 0.17 

VEMDSC02 5/2/1994 8.73 1.0705 0.245 

VEMDSC04 5/2/1994 21.3 1.019 0.27 

VEMDSC05 5/2/1994 23.91 1.005 0.36 

VEMDSC04 6/6/1994 1.1 13.924 6.32 0.841 0.38 

VEMDSC05 6/6/1994 2.68 31.5294 1.85 1.41 0.28 

VEMDSC02 6/6/1994 5.05 66.44735 10.455 1.982 0.205 

VEMDSC01 6/6/1994 5.99 78.8158 7.35 1.481 0.15 

VEMDSC04 7/6/1994 3.4 40.4762 5.92 1.914 0.17 

VEMDSC05 7/6/1994 4.3 51.1904 1 2.172 0.16 

VEMDSC02 7/6/1994 4.42 56.6666 9.86 1.578 0.23 

VEMDSC01 7/6/1994 4.91 62.9487 5.9 1.439 0.15 

VEMDSC01 8/1/1994 10.39 

VEMDSC02 8/1/1994 44.785 1.7185 0.265 

VEMDSC04 8/1/1994 1 2.294 0.61 

VEMDSC05 8/1/1994 1 2.349 0.53 

VEMDSC04 9/6/1994 3.44 40.9523 1 2.04 0.22 

VEMDSC05 9/6/1994 4.26 50.1176 1.24 1.94 0.19 

VEMDSC02 9/6/1994 4.37 53.9506 3.49 0.952 0.15 

VEMDSC01 9/6/1994 5.49 69.4936 5.19 0.478 0.09 

VEMDSC04 10/3/1994 4.25 50.5952 1 2.717 0.19 

VEMDSC05 10/3/1994 4.715 56.1309 1 2.4305 0.22 

VEMDSC02 10/3/1994 5.31 64.7561 3.61 1.526 0.29 

VEMDSC01 10/3/1994 5.61 68.4146 3.45 1.643 0.16 

VEMDSC04 11/1/1994 4.285 49.2528 1.765 1.746 0.625 

VEMDSC02 11/1/1994 4.55 54.1666 1.77 1.226 0.25 

VEMDSC05 11/1/1994 4.92 56.5517 1.01 3.648 0.42 

VEMDSC01 11/1/1994 5.19 61.7857 2.87 0.944 0.19 

VEMDSC04 12/5/1994 3.87 43 1.78 0.872 0.17 

VEMDSC05 12/5/1994 4.55 50.5555 1 1.145 0.15 

VEMDSC02 12/5/1994 5.22 60 1.37 1.163 0.14 

VEMDSC01 12/5/1994 6.29 72.2988 5.68 0.949 0.11 

VEMDSC04 1/9/1995 6.24 60 1 1.448 0.2 

VEMDSC05 1/9/1995 6.79 64.0566 1 1.519 0.07 
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

DO DOSAT Corr Chla TN TP Station Sample Date 

Florida Department of Environmental Protection 

50

(mg/L) (%) (μg/L) (mg/L) (mg/L) 

VEMDSC02 1/9/1995 6.59 64.6078 1.15 1.054 0.14 

VEMDSC01 1/9/1995 7.6 73.0769 3.79 0.801 0.12 

VEMDSC04 2/6/1995 2.98 29.8 1 1.071 0.08 

VEMDSC05 2/6/1995 5.65 54.3269 1 0.918 0.07 

VEMDSC01 2/6/1995 7.9 73.1481 1.73 0.542 0.08 

VEMDSC02 2/6/1995 8.14 76.7924 3.63 0.848 0.09 

VEMDSC05 3/6/1995 3.21 34.1489 3.475 1.016 0.12 

VEMDSC04 3/6/1995 3.9 41.4893 13.19 0.851 0.13 

VEMDSC01 3/6/1995 5.9 64.1304 2.43 0.555 0.1 

VEMDSC02 3/6/1995 6.5 72.2222 5.43 0.626 0.07 

VEMDSC05 4/3/1995 3.71 38.2474 1 1.239 0.12 

VEMDSC04 4/3/1995 4.05 42.6315 4.77 0.949 0.16 

VEMDSC01 4/3/1995 6.2 65.9574 1.85 0.397 0.11 

VEMDSC02 4/3/1995 6.075 66.03255 3.435 0.584 0.11 

VEMDSC04 5/1/1995 2.1 25.6097 20.08 0.572 0.34 

VEMDSC05 5/1/1995 2.8 32.1839 8.05 0.872 0.13 

VEMDSC01 5/1/1995 4.72 57.5609 3.21 0.576 0.23 

VEMDSC02 5/1/1995 5.24 64.6913 5.16 0.422 0.22 

VEMDSC04 6/5/1995 1.45 15.2791 9.06 1.1025 0.275 

VEMDSC05 6/5/1995 4.7 55.9523 3.76 0.93 0.26 

VEMDSC02 6/5/1995 5.5 69.6203 10.38 1.048 0.2 

VEMDSC01 6/5/1995 6.4 79.0123 6.59 0.56 0.32 

VEMDSC04 7/10/1995 2.17 27.8205 23.32 1.1755 0.32 

VEMDSC05 7/10/1995 3.12 39.4936 41.42 

VEMDSC01 7/10/1995 4.88 62.5641 3.58 0.068 0.16 

VEMDSC02 7/10/1995 4.97 65.3947 5.96 0.096 0.2 

VEMDSC04 8/7/1995 3.23 39.8765 1 1.782 0.14 

VEMDSC05 8/7/1995 3.94 48.0488 1 1.922 0.2 

VEMDSC02 8/7/1995 4.3 56.5789 26.41 1.939 0.24 

VEMDSC01 8/7/1995 4.31 57.4666 5.78 1.229 0.25 

VEMDSC01 9/5/1995 3.87 1.334 0.2 

VEMDSC02 9/5/1995 1 1.507 0.22 

VEMDSC04 9/5/1995 1 1.6725 0.255 

VEMDSC05 9/5/1995 1.77 1.862 0.2 

VEMDSC04 10/2/1995 3.8 46.9135 1.457 0.17 

VEMDSC02 10/2/1995 4.3 54.4303 1.429 0.23 

VEMDSC05 10/2/1995 4.6 56.7901 1.585 0.14 

VEMDSC01 10/2/1995 5.1 64.5569 1.368 0.19 

VEMDSC04 11/6/1995 3.32 37.7272 1.01 1.38 0.08 

VEMDSC05 11/6/1995 4.15 46.1111 1.64 1.39 0.05 

VEMDSC02 11/6/1995 6.03 69.3103 3.2 0.862 0.25 
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

DO DOSAT Corr Chla TN TP Station Sample Date 

Florida Department of Environmental Protection 

51

(mg/L) (%) (μg/L) (mg/L) (mg/L) 

VEMDSC01 11/6/1995 6.42 75.5294 4.57 0.595 0.3 

VEMDSC04 12/4/1995 2.75 29.2553 3.12 0.764 0.14 

VEMDSC01 12/4/1995 7.17 81.4772 2.85 0.714 0.16 

VEMDSC02 12/4/1995 1 0.908 0.16 

VEMDSC04 1/8/1996 7.67 69.45945 1 1.201 0.07 

VEMDSC05 1/8/1996 7.99 70.7079 1 1.174 0.07 

VEMDSC02 1/8/1996 8.36 73.9823 2.72 1.128 0.08 

VEMDSC01 1/8/1996 8.76 81.1111 8.3 0.683 0.15 

VEMDSC04 2/5/1996 5.85 55.1886 1 1.491 0.24 

VEMDSC05 2/5/1996 6.8 61.2612 1 1.326 0.11 

VEMDSC02 2/5/1996 8.155 73.46845 2.31 0.824 0.14 

VEMDSC01 2/5/1996 8.44 76.036 2.42 0.622 0.11 

VEMDSC05 3/4/1996 4.97 49.1784 1.365 1.32 0.15 

VEMDSC04 3/4/1996 5.54 55.4 2.99 2.22 0.41 

VEMDSC02 3/4/1996 7.1 74.7368 1.85 0.645 0.14 

VEMDSC01 3/4/1996 7.55 79.4736 1.81 0.483 0.2 

VEMDSC05 4/1/1996 5.325 57.8804 1.76 1.007 0.165 

VEMDSC02 4/1/1996 5.37 58.3695 1.54 0.986 0.24 

VEMDSC04 4/1/1996 5.59 60.7608 1.07 1.01 0.22 

VEMDSC01 4/1/1996 6.07 68.9772 2.12 0.522 0.34 

VEMDSC05 5/6/1996 4.02 46.2069 10.33 1.026 0.12 

VEMDSC04 5/6/1996 5.035 61.4024 74.98 1.139 0.175 

VEMDSC01 5/6/1996 5.33 65 2.19 0.355 0.13 

VEMDSC02 5/6/1996 5.86 75.1282 3.52 0.482 0.1 

VEMDSC05 6/3/1996 1.8 20.9317 232.985 0.413 0.08 

VEMDSC04 6/3/1996 4.46 54.3902 12.4 0.476 0.1 

VEMDSC02 6/3/1996 5.17 63.0488 3.37 0.309 0.33 

VEMDSC01 6/3/1996 5.41 64.4047 2.49 0.322 0.23 

VEMDSC02 7/8/1996 3.89 48.0247 6.89 1.328 0.4 

VEMDSC01 7/8/1996 3.92 48.395 1.67 0.94 0.2 

VEMDSC04 7/8/1996 4.59 54.6428 2.19 1.352 0.34 

VEMDSC05 7/8/1996 5.04 59.99995 1.705 1.4835 0.235 

VEMDSC01 8/5/1996 3.8 0.477 0.16 

VEMDSC02 8/5/1996 2.62 0.529 0.13 

VEMDSC04 8/5/1996 61.13 0.612 0.17 

VEMDSC05 8/5/1996 21.2 0.794 0.125 

VEMDSC04 9/3/1996 0.52 6.58228 31.15 0.661 0.26 

VEMDSC05 9/3/1996 1.9 22.619 4.35 0.858 0.15 

VEMDSC01 9/3/1996 4.94 65 4.97 0.62 0.17 

VEMDSC02 9/3/1996 5.06 66.5789 7.9 0.603 0.13 

VEMDSC02 10/7/1996 4.96 58.3529 2.26 0.977 0.29 
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Station Sample Date DO 

(mg/L) 

DOSAT 

(%) 

Corr Chla 

(μg/L) 

TN 

(mg/L) 

TP 

(mg/L) 

VEMDSC01 10/7/1996 5.03 59.1764 2.56 0.641 0.23 

VEMDSC04 10/7/1996 5.33 61.2643 1.95 1.276 0.53 

VEMDSC05 10/7/1996 5.77 66.3218 1.09 1.319 0.43 

VEMDSC04 11/4/1996 2.79 31.7045 1 0.949 0.12 

VEMDSC05 11/4/1996 3.59 39.0217 1 1.044 0.08 

VEMDSC02 11/4/1996 6.43 73.0681 2.38 0.874 0.12 

VEMDSC01 11/4/1996 6.82 75.7777 2.55 0.665 0.13 

VEMDSC05 12/2/1996 2.75 29.2553 1 0.475 0.11 

VEMDSC04 12/2/1996 3.05 33.1521 1.99 0.58 0.11 

VEMDSC02 12/2/1996 7.23 80.3333 5.42 0.601 0.12 

VEMDSC01 12/2/1996 7.69 83.5869 14.35 0.43 0.1 

VEMDSC04 1/6/1997 0.69 7.66666 1.14 0.59 0.12 

VEMDSC05 1/6/1997 2.72 28.9361 1 0.425 0.2 

VEMDSC02 1/6/1997 5.51 61.2222 4.14 0.357 0.12 

VEMDSC01 1/6/1997 7.07 78.5555 2.82 0.298 0.22 

VEMDSC05 2/3/1997 0.295 3.138295 1.035 0.597 0.095 

VEMDSC04 2/3/1997 0.32 3.40425 1.54 0.876 0.2 

VEMDSC02 2/3/1997 7.56 79.5789 3.24 0.588 0.1 

VEMDSC01 2/3/1997 9.99 105.158 1.26 0.416 0.1 

VEMDSC05 3/3/1997 0.57 6.47727 11.11 0.648 0.11 

VEMDSC04 3/3/1997 0.7 8.04597 3.06 

VEMDSC02 3/3/1997 6.66 79.2857 5.23 0.488 0.12 

VEMDSC01 3/3/1997 7.45 87.647 3.96 0.454 0.17 

VEMDSC05 4/7/1997 0.72 8.47059 22.18 0.583 0.2 

VEMDSC02 4/7/1997 5.075 58.3333 3.16 0.502 0.17 

VEMDSC04 4/7/1997 5.12 60.2353 10.94 0.703 0.17 

VEMDSC01 4/7/1997 7.32 84.1379 1.97 0.411 0.12 

VEMDSC01 5/5/1997 4.34 0.467 0.12 

VEMDSC02 5/5/1997 4.01 0.5035 0.115 

VEMDSC04 5/5/1997 3.61 0.466 0.14 

VEMDSC05 5/5/1997 8.08 0.459 0.14 

VEMDSC05 6/2/1997 0.61 7.17647 1.44 0.664 0.17 

VEMDSC04 6/2/1997 4.77 56.1176 0.628 0.19 

VEMDSC02 6/2/1997 4.805 58.59755 5.525 0.5415 0.135 

VEMDSC01 6/2/1997 5.88 71.7073 3.86 0.47 0.12 

VEMDSC04 7/7/1997 1.43 17.6543 1 0.77 0.21 

VEMDSC05 7/7/1997 2.42 28.4706 1 1.685 0.35 

VEMDSC01 7/7/1997 5.04 66.3158 1.84 0.644 0.12 

VEMDSC02 7/7/1997 5.065 66.6447 2.2 0.621 0.145 

VEMDSC05 8/4/1997 3.65 43.4523 1 1.586 0.21 

VEMDSC01 8/4/1997 6.62 0.714 0.13 

Florida Department of Environmental Protection 

52
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Station Sample Date DO 

(mg/L) 

DOSAT 

(%) 

Corr Chla 

(μg/L) 

TN 

(mg/L) 

TP 

(mg/L) 

VEMDSC02 8/4/1997 10.19 0.713 0.145 

VEMDSC04 8/4/1997 3.84 1.312 0.21 

VEMDSC04 9/8/1997 3.24 38.1176 1 1.238 0.22 

VEMDSC02 9/8/1997 3.59 43.7805 6.02 1.169 0.21 

VEMDSC05 9/8/1997 3.89 45.7647 1 1.249 0.18 

VEMDSC01 9/8/1997 4.42 0.764 0.13 

VEMDSC04 10/6/1997 0.24 2.92683 9.29 0.919 0.19 

VEMDSC05 10/6/1997 3.12 35.862 1 0.891 0.09 

VEMDSC02 10/6/1997 5.875 71.6463 3.57 0.758 0.1 

VEMDSC01 10/6/1997 6.1 75.3086 3.07 0.571 0.04 

VEMDSC04 11/3/1997 4.69 52.1111 1 1.485 0.44 

VEMDSC05 11/3/1997 5.44 57.8723 1 1.156 0.27 

VEMDSC02 11/3/1997 5.57 64.0229 1.96 1.254 0.26 

VEMDSC01 11/3/1997 7.54 88.7058 3.32 0.716 0.15 

VEMDSC04 12/1/1997 3.18 33.8298 17.29 0.823 0.14 

VEMDSC05 12/1/1997 3.63 38.617 1 0.847 0.14 

VEMDSC02 12/1/1997 6.81 72.4468 1 0.797 0.1 

VEMDSC01 12/1/1997 7.08 76.9565 1.29 0.55 0.09 

VEMDSC04 1/5/1998 6.48 66.8041 1 1.057 0.12 

VEMDSC05 1/5/1998 6.85 70.6185 1 1.107 0.1 

VEMDSC02 1/5/1998 6.89 72.5263 1.01 1.091 0.11 

VEMDSC01 1/5/1998 7.67 81.5957 2.29 1.1 0.12 

VEMDSC04 2/2/1998 6.42 62.9411 1 1.103 0.15 

VEMDSC05 2/2/1998 6.57 64.4117 1 1.096 0.11 

VEMDSC02 2/2/1998 7.625 76.25 1.005 0.7125 0.07 

VEMDSC01 2/2/1998 7.79 77.9 1 0.489 0.05 

VEMDSC02 3/2/1998 6.09 64.1052 1 0.885 0.17 

VEMDSC04 3/2/1998 6.3 64.9484 1 1.079 0.2 

VEMDSC05 3/2/1998 6.79 70 1 1.122 0.16 

VEMDSC01 3/2/1998 7.06 74.3158 1 0.07 

VEMDSC05 4/6/1998 4.4 46.8085 1 1.034 0.07 

VEMDSC04 4/6/1998 4.3 47.7777 3.58 0.901 0.08 

VEMDSC02 4/6/1998 4.4 48.8889 3 0.6 0.13 

VEMDSC01 4/6/1998 7 79.5455 2.44 0.418 0.1 

VEMDSC01 5/4/1998 2.63 0.563 0.1 

VEMDSC02 5/4/1998 3.45 0.11 

VEMDSC04 5/4/1998 0.551 0.1 

VEMDSC05 5/4/1998 5.52 0.692 0.19 

VEMDSC04 6/1/1998 1.57 20.1282 9.46 0.502 0.17 

VEMDSC05 6/1/1998 2.22 27.4074 8.02 0.794 0.51 

VEMDSC02 6/1/1998 5.36 70.5263 3.81 0.517 0.15 

Florida Department of Environmental Protection 

53
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Station Sample Date DO 

(mg/L) 

DOSAT 

(%) 

Corr Chla 

(μg/L) 

TN 

(mg/L) 

TP 

(mg/L) 

VEMDSC01 6/1/1998 5.95 78.2894 4.6 0.461 0.13 

VEMDSC05 7/6/1998 0.15 1.97368 8.41 1.128 0.64 

VEMDSC04 7/6/1998 0.85 11.3333 11.58 0.43 

VEMDSC02 7/6/1998 4.7 62.6666 5.66 0.521 0.18 

VEMDSC01 7/6/1998 5.505 73.4 3.82 0.4845 0.175 

VEMDSC04 8/3/1998 0.07 0.933333 48.48 1.468 0.51 

VEMDSC05 8/3/1998 1.52 18.5366 1.7 1.459 0.44 

VEMDSC02 8/3/1998 4.61 60.6579 6.89 0.562 0.19 

VEMDSC01 8/3/1998 6.07 79.8684 4.24 0.3368 0.14 

VEMDSC04 9/8/1998 2.39 29.1463 8.09 1.2764 0.35 

VEMDSC05 9/8/1998 2.84 34.6341 1 1.3095 0.24 

VEMDSC02 9/8/1998 4.745 60.83335 5.04 0.595 0.165 

VEMDSC01 9/8/1998 5.16 63.7037 4.13 0.2286 0.08 

VEMDSC04 10/5/1998 4.02 49.0244 1.27 

VEMDSC05 10/5/1998 4.27 52.0731 1 

VEMDSC02 10/5/1998 4.3 54.4303 4.15 

VEMDSC01 10/5/1998 4.9 62.8205 4.45 

VEMDSC01 10/6/1998 0.11 

VEMDSC02 10/6/1998 0.18 

VEMDSC04 10/6/1998 0.24 

VEMDSC05 10/6/1998 0.23 

VEMDSC04 11/2/1998 3.68 40.8889 4.89 1.102 0.17 

VEMDSC05 11/2/1998 3.97 44.1111 1 1.335 0.17 

VEMDSC02 11/2/1998 5.01 59.6428 2.89 0.723 0.09 

VEMDSC01 11/2/1998 5.63 67.0238 4.33 0.53 0.09 

VEMDSC05 12/2/1998 0.35 3.88889 1.3 0.827 0.18 

VEMDSC04 12/2/1998 3.68 40.8889 263.06 0.723 0.14 

VEMDSC02 12/2/1998 6.6 75.862 3.73 0.368 0.12 

VEMDSC01 12/2/1998 6.55 77.0588 3.92 0.304 0.1 

VEMDVC-074 1/4/1999 3.57 37.90316 1 0.527 0.14 

VEMDVC-073 1/4/1999 3.26 39.8186 2.285 0.462 0.11 

VEMDVC-072 1/4/1999 6.64 87.66389 1.28 0.306 0.1 

VEMDVC-071 1/4/1999 7.27 93.1 3.2 0.487 0.01 

VEMDVC-074 2/1/1999 3.05 35.83873 1.11 0.813 0.18 

VEMDVC-073 2/1/1999 4.18 51.94915 2.88 0.675 0.13 

VEMDVC-071 2/1/1999 5.63 74.6 2.2 0.253 0.1 

VEMDVC-072 2/1/1999 5.71 83.02783 0.229 0.17 

VEMDVC-074 3/1/1999 1.83 22.47503 1 0.657 0.14 

VEMDVC-073 3/1/1999 6.03 72.57485 6.04 0.704 0.12 

VEMDVC-071 3/1/1999 8.31 102.7 1.1 0.242 0.12 

VEMDVC-072 3/1/1999 8.31 113.2818 1.73 0.256 0.4 

Florida Department of Environmental Protection 

54
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Station Sample Date DO 

(mg/L) 

DOSAT 

(%) 

Corr Chla 

(μg/L) 

TN 

(mg/L) 

TP 

(mg/L) 

VEMDVC-072 4/5/1999 5.27 84.6 2.76 0.447 0.1 

VEMDVC-071 4/5/1999 6.35 94.3 3.3 0.274 0.09 

VEMDVC-073 4/5/1999 5 0.425 0.12 

VEMDVC-074 4/5/1999 3.8 0.82 0.24 

VEMDVC-074 5/3/1999 1.27 17.32478 1 0.847 0.3 

VEMDVC-073 5/3/1999 1.79 24.83932 3.87 0.658 0.21 

VEMDVC-071 5/3/1999 6.48 89.5 2.6 0.338 0.19 

VEMDVC-072 5/3/1999 6.4 94.93836 2.86 0.372 0.19 

VEMDVC-073 6/7/1999 0.95 14.84744 12.2 0.749 0.3 

VEMDVC-074 6/7/1999 1.55 22.03065 13.2 0.632 0.29 

VEMDVC-072 6/7/1999 4.96 82.10178 6.7 0.594 0.17 

VEMDVC-071 6/7/1999 5.6 85.6 5.7 0.486 0.14 

VEMDVC-074 7/7/1999 4.04 54.28378 1.7 1.546 0.15 

VEMDVC-073 7/7/1999 4.1 56.66585 8.6 1.716 0.18 

VEMDVC-071 7/7/1999 5.24 83 10.1 0.917 0.19 

VEMDVC-072 7/7/1999 6.03 93.70771 63 1.26 0.21 

VEMDVC-073 8/2/1999 0.22 3.198505 5.8 1.137 0.43 

VEMDVC-072 8/2/1999 4.07 70.23625 3.53 0.579 0.18 

VEMDVC-071 8/2/1999 5.39 85.8 6.6 0.416 0.14 

VEMDVC-074 9/7/1999 0.28 4.2 1.3 0.848 0.25 

VEMDVC-073 9/7/1999 1.5 22.4 3.2 0.851 0.15 

VEMDVC-072 9/7/1999 4.4 74.1 7.6 0.455 0.15 

VEMDVC-071 9/7/1999 5.11 81.1 5.5 0.417 0.16 

VEMDVC-072 10/4/1999 3.34 45.5 1.4 1.643 0.28 

VEMDVC-073 10/4/1999 3.5 47.1 1.11 1.973 0.32 

VEMDVC-071 10/4/1999 4.11 54.0 1.8 1.507 0.2 

VEMDVC-074 10/4/1999 

VEMDVC-074 11/1/1999 4.14 52.5 1 1.427 0.13 

VEMDVC-073 11/1/1999 4.34 55.3 1 1.387 0.15 

VEMDVC-072 11/1/1999 4.46 59.2 2.5 1.283 0.19 

VEMDVC-071 11/1/1999 5.64 73.9 2.5 1.283 0.19 

VEMDVC-074 12/6/1999 3.51 40.9 1 0.88 0.11 

VEMDVC-073 12/6/1999 4.37 50.0 2.7 0.91 0.15 

VEMDVC-072 12/6/1999 6.74 91.0 1.2 0.54 0.1 

VEMDVC-071 12/6/1999 7.39 94.5 1.4 0.534 0.08 

VEMDVC-073 1/3/2000 2.43 28.3 1 0.81 0.09 

VEMDVC-074 1/3/2000 2.89 34.4 1 0.83 0.09 

VEMDVC-072 1/3/2000 6.95 91.3 2.55 0.64 0.09 

VEMDVC-071 1/3/2000 8.14 104.3 1.66 0.397 0.07 

VEMDVC-073 4/3/2000 4.13 51.7 3.27 1.08 0.22 

VEMDVC-074 4/3/2000 4.3 53.7 1.55 1.01 0.19 

Florida Department of Environmental Protection 

55
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Station Sample Date DO 

(mg/L) 

DOSAT 

(%) 

Corr Chla 

(μg/L) 

TN 

(mg/L) 

TP 

(mg/L) 

VEMDVC-072 4/3/2000 6.07 81.9 4.88 0.93 0.25 

VEMDVC-071 4/3/2000 7.72 102.1 7.51 0.553 0.2 

VEMDVC-074 7/10/2000 0.79 11.3 14.76 0.76 0.24 

VEMDVC-073 7/10/2000 2.74 39.8 4.43 0.66 0.24 

VEMDVC-072 7/10/2000 4.79 79.4 2.56 0.518 0.14 

VEMDVC-073 10/2/2000 2.77 36.2 4.06 1.07 0.2 

VEMDVC-074 10/2/2000 3.54 46.0 1.06 1.09 0.16 

VEMDVC-072 10/2/2000 4.49 66.2 4.72 0.76 0.14 

VEMDVC-074 2/5/2001 0.01 0.1 1 0.73 0.41 

VEMDVC-073 2/5/2001 0.04 0.5 23.36 1.01 0.25 

VEMDVC-072 2/5/2001 6.85 88.9 2.05 0.46 0.08 

VEMDVC-071 2/5/2001 8.97 111.1 0.86 0.281 0.07 

VEMDVC-071 5/7/2001 0.53 7.9 3.44 0.271 0.12 

VEMDVC-074 5/7/2001 0.91 12.2 20.67 0.72 0.16 

VEMDVC-073 5/7/2001 4.92 67.3 7.5 0.59 0.16 

VEMDVC-072 5/7/2001 5.19 83.0 3.85 0.36 0.12 

VEMDVC-072 8/6/2001 3.81 51.9 7.52 1.63 0.22 

VEMDVC-073 8/6/2001 4.46 59.6 1 1.77 0.31 

VEMDVC-074 8/6/2001 4.76 63.1 1.55 2 0.31 

VEMDVC-071 8/6/2001 4.34 63.6 5.8 0.938 0.22 

VEMDVC-073 11/5/2001 4.94 62.1 1 1.36 0.04 

VEMDVC-074 11/5/2001 5.25 65.7 1 1.33 0.05 

VEMDVC-072 11/5/2001 6.23 88.6 1 0.85 0.07 

VEMDVC-071 11/5/2001 7.19 103.2 1.69 0.303 0.19 

VEMDVC-072 3/4/2002 7.24 86.6 1 

VEMDVC-071 3/4/2002 7.02 86.8 0.8 0.363 0.06 

VEMDVC-072 6/3/2002 4.69 80.2 6.1 

VEMDVC-071 6/3/2002 5.35 86.1 4.4 0.468 0.15 

VEMDVC-071 9/9/2002 5.75 89.9 0.2 

VEMDVC-072 12/2/2002 7.22 94.6 

VEMDVC-071 12/2/2002 7.73 99.2 1.9 0.027 

VEMDVC-074 2/3/2003 5.13 55.6 0.913 0.08 

VEMDVC-073 2/3/2003 5.57 59.9 0.821 0.09 

VEMDVC-071 2/3/2003 8.48 103.9 2.58 0.316 0.1 

VEMDVC-072 2/3/2003 8.5 108.0 0.536 0.08 

WPB 20010738 3/12/2003 5.88 72.0 1 1.158 0.133 

WPB 20010737 3/12/2003 7.505 95.2 33.39722 1.222 0.148 

VEMDVC-074 5/5/2003 2.54 33.0 1.024 0.15 

VEMDVC-073 5/5/2003 3.45 46.2 0.914 0.15 

VEMDVC-072 5/5/2003 5.73 90.5 0.582 0.16 

VEMDVC-071 5/5/2003 2.72 0.356 0.18 

Florida Department of Environmental Protection 

56
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Station Sample Date DO 

(mg/L) 

DOSAT 

(%) 

Corr Chla 

(μg/L) 

TN 

(mg/L) 

TP 

(mg/L) 

WPB 20010738 6/4/2003 2.53 38.2 8.99 0.573 0.1 

WPB 20010737 6/4/2003 7.1 95.8 13.92 1.125 0.093 

VEMDVC-072 8/4/2003 4.01 58.0 

VEMDVC-073 8/4/2003 4.31 58.1 

VEMDVC-071 8/4/2003 4.32 61.9 2.69 0.923 0.19 

VEMDVC-074 8/4/2003 4.74 63.8 

WPB 20010738 8/13/2003 4.86 66.2 1.89 1.262 0.236 

WPB 20010737 8/13/2003 6.925 99.9 24.53 1.069 0.089 

WPB 20010738 8/26/2003 2.8 38.1 11.71 1.685 0.325 

WPB 20010737 8/26/2003 6.93 103.5 7.18 0.9 0.059 

WPB 20010738 9/15/2003 3.23 43.0 1.41 1.081 0.122 

WPB 20010737 9/15/2003 6.69 96.4 19.19 0.934 0.076 

WPB 20010738 10/9/2003 5.28 68.6 1 1.188 0.195 

WPB 20010737 10/9/2003 6.17 84.3 16.14 1.085 0.091 

VEMDVC-074 11/3/2003 2.64 34.0 

VEMDVC-073 11/3/2003 3.27 42.6 

VEMDVC-072 11/3/2003 5.83 88.3 

VEMDVC-071 11/3/2003 6.87 102.1 3.34 0.08 

VEMDVC-074 3/1/2004 6.29 69.7 1.12 

VEMDVC-073 3/1/2004 6.4 71.2 1 

VEMDVC-072 3/1/2004 7.32 88.1 1.95 

VEMDVC-071 3/1/2004 9.2 107.3 1.64 

VEMDVC-073 6/7/2004 3.08 42.7 

VEMDVC-071 6/7/2004 5.53 83.3 

VEMDVC-072 6/7/2004 5.58 88.2 

VEMDVC-073 10/11/2004 3.1 40.9 

VEMDVC-074 10/11/2004 3.42 45.0 

VEMDVC-072 10/11/2004 4.95 69.4 

VEMDVC-074 12/6/2004 4.21 48.7 

VEMDVC-073 12/6/2004 4.74 55.2 

VEMDVC-071 12/6/2004 6.87 91.4 

VEMDVC-072 12/6/2004 9.2 120.9 

VEMDVC-074 2/7/2005 5.95 67.3 

VEMDVC-073 2/7/2005 7.09 83.0 

VEMDVC-071 2/7/2005 8.52 107.1 2.16 0.345 0.07 

VEMDVC-072 2/7/2005 8.51 115.6 

CEN 27010197 2/9/2005 5.07 65.6 2.88 0.761 0.081 

CEN 27010195 2/9/2005 5.65 74.1 3.96 0.729 0.08 

CEN 27010196 2/9/2005 5.73 74.5 4.54 0.743 0.077 

CEN 27010194 2/9/2005 6.05 79.5 1.43 0.648 0.07 

CEN 27010193 2/9/2005 6.15 81.2 3.18 0.646 0.0585 

Florida Department of Environmental Protection 

57
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Station Sample Date DO 

(mg/L) 

DOSAT 

(%) 

Corr Chla 

(μg/L) 

TN 

(mg/L) 

TP 

(mg/L) 

CEN 27010194 4/5/2005 5.6 1 1.207 0.092 

CEN 27010194 4/18/2005 6.38 83.6 

CEN 27010196 4/18/2005 6.42 84.1 

CEN 27010197 4/18/2005 6.46 84.3 

CEN 27010195 4/18/2005 6.44 84.5 

CEN 27010193 4/18/2005 6.5 85.4 

VEMDVC-074 5/2/2005 4.25 53.2 

VEMDVC-073 5/2/2005 5.16 65.9 

VEMDVC-071 5/2/2005 7.18 99.5 7.14 0.473 0.13 

VEMDVC-072 5/2/2005 7.09 100.3 

CEN 27010193 6/13/2005 3.68 3.475 1.381 0.315 

CEN 27010194 6/13/2005 3.7 4.04 1.228 0.29 

CEN 27010195 6/13/2005 3.72 3.98 1.229 0.27 

CEN 27010196 6/13/2005 3.76 

CEN 27010197 6/13/2005 3.7 

CEN 27010197 6/29/2005 4.38 61.5 

VEMDVC-072 8/8/2005 4.19 60.3 4.21 

VEMDVC-073 8/8/2005 5.01 67.5 2.29 

VEMDVC-074 8/8/2005 5.34 71.8 1.43 

VEMDVC-071 8/8/2005 4.92 73.5 1.79 

CEN 27010193 8/8/2005 4.34 2.37 1.438 0.35 

CEN 27010194 8/8/2005 4.31 3.42 1.237 0.36 

CEN 27010195 8/8/2005 4.21 3.42 1.236 0.31 

CEN 27010196 8/8/2005 4.29 

CEN 27010197 8/8/2005 4.18 

VEMDVC-074 11/7/2005 6.42 78.8 

VEMDVC-073 11/7/2005 6.43 80.7 

VEMDVC-072 11/7/2005 7.13 97.6 

VEMDVC-071 11/7/2005 7.4 100.8 3.87 0.09 

CEN 27010193 12/12/2005 6.05 69.1 2.55 0.13 

CEN 27010196 12/12/2005 6.17 69.2 

CEN 27010194 12/12/2005 6.04 69.3 2.71 0.14 

CEN 27010195 12/12/2005 6.42 72.8 2.63 0.1 

CEN 27010197 12/12/2005 6.54 72.8 

VEMDVC-073 1/9/2006 5.34 56.7 2.45 

VEMDVC-072 1/9/2006 7.52 90.2 1.58 

VEMDVC-071 1/9/2006 8.72 102.1 1.04 0.223 0 

VEMDVC-073 4/3/2006 5.97 77.8 

VEMDVC-071 4/3/2006 6.48 85.9 1.03 0.27 0.22 

VEMDVC-071 7/10/2006 2.07 

VEMDVC-072 7/10/2006 5.29 

Florida Department of Environmental Protection 

58
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Station Sample Date DO 

(mg/L) 

DOSAT 

(%) 

Corr Chla 

(μg/L) 

TN 

(mg/L) 

TP 

(mg/L) 

VEMDVC-073 7/10/2006 17.88 0.03 

VEMDVC-073 10/3/2006 2.79 36 13.29 0.21 

VEMDVC-073 10/3/2006 2.79 39.5 13.29 

VEMDVC-072 10/3/2006 5.99 88.5 6.72 0.12 

VEMDVC-072 10/3/2006 5.99 96.8 6.72 

VEMDVC-071 10/3/2006 6.35 97.3 7.01 0.09 

Florida Department of Environmental Protection 

59
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Appendix C: Kruskal–Wallis Analysis of DO, DOSAT, Corrected Chla, 

TN, and TP Observations versus Season in Spruce Creek 

Kruskal-Wallis One-Way Analysis of Variance for 492 cases 

Dependent variable is DO 

 Grouping variable is SEASON$ 

 

 Group Count Rank Sum 

 

 FALL 133 33366.000 

 SPRING 122 28163.500 

 SUMMER 113 18079.000 

 WINTER 124 41669.500 

 

Kruskal-Wallis Test Statistic = 92.632 

Probability is 0.000 assuming Chi-square distribution with 3 df 

Kruskal-Wallis One-Way Analysis of Variance for 481 cases 

Dependent variable is DOSAT 

 Grouping variable is SEASON$ 

 

 Group Count Rank Sum 

 

 FALL 133 32272.500 

 SPRING 116 28035.500 

 SUMMER 108 20317.500 

 WINTER 124 35295.500 

 

Kruskal-Wallis Test Statistic = 27.874 

Probability is 0.000 assuming Chi-square distribution with 3 df 

Kruskal-Wallis One-Way Analysis of Variance for 459 cases 

Dependent variable is CHLAC 

 Grouping variable is SEASON$ 

 

 Group Count Rank Sum 

 

 FALL 110 21742.500 

 SPRING 107 31267.500 

 SUMMER 125 34480.000 

 WINTER 117 18080.000 

 

Kruskal-Wallis Test Statistic = 83.378 

Probability is 0.000 assuming Chi-square distribution with 3 df 

Florida Department of Environmental Protection 

60
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Kruskal-Wallis One-Way Analysis of Variance for 435 cases 

Dependent variable is TN 

 Grouping variable is SEASON$ 

 

 Group Count Rank Sum 

 

 FALL 97 23811.000 

 SPRING 111 18692.500 

 SUMMER 112 29324.000 

 WINTER 115 23002.500 

 

Kruskal-Wallis Test Statistic = 37.870 

Probability is 0.000 assuming Chi-square distribution with 3 df 

Kruskal-Wallis One-Way Analysis of Variance for 459 cases 

Dependent variable is TP 

 Grouping variable is SEASON$ 

 

 Group Count Rank Sum 

 

 FALL 111 24608.500 

 SPRING 118 29985.500 

 SUMMER 113 33349.000 

 WINTER 117 17627.000 

 

Kruskal-Wallis Test Statistic = 73.545 

Probability is 0.000 assuming Chi-square distribution with 3 df 

Florida Department of Environmental Protection 

61
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Appendix D: Kruskal–Wallis Analysis of DO, DOSAT, Corrected Chla, TN, and 

TP Observations versus Month in Spruce Creek 

Kruskal-Wallis One-Way Analysis of Variance for 492 cases 

Dependent variable is DO 

 Grouping variable is MONTH 

 

 Group Count Rank Sum 

 

 1 39 12790.500 

 2 49 16398.500 

 3 36 12480.500 

 4 43 12387.000 

 5 33 7512.500 

 6 46 8264.000 

 7 37 5457.000 

 8 42 7277.500 

 9 34 5344.500 

 10 44 9041.000 

 11 44 11385.000 

 12 45 12940.000 

 

Kruskal-Wallis Test Statistic = 114.195 

Probability is 0.000 assuming Chi-square distribution with 11 df 

Kruskal-Wallis One-Way Analysis of Variance for 481 cases 

Dependent variable is DOSAT 

 Grouping variable is MONTH 

 

 Group Count Rank Sum 

 

 1 39 10571.500 

 2 49 13963.500 

 3 36 10760.500 

 4 42 11531.000 

 5 33 7864.500 

 6 41 8640.000 

 7 37 6333.500 

 8 37 7832.000 

 9 34 6152.000 

 10 44 9542.000 

 11 44 11036.500 

 12 45 11694.000 

 

Kruskal-Wallis Test Statistic = 37.086 

Probability is 0.000 assuming Chi-square distribution with 11 df 

Florida Department of Environmental Protection 

62
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Kruskal-Wallis One-Way Analysis of Variance for 459 cases 

Dependent variable is CHLAC 

 Grouping variable is MONTH 

 

 Group Count Rank Sum 

 

 1 35 5485.500 

 2 42 6308.500 

 3 40 6286.000 

 4 34 7477.000 

 5 34 10673.500 

 6 39 13117.000 

 7 40 12218.500 

 8 47 13079.500 

 9 38 9182.000 

 10 37 8333.000 

 11 38 6000.000 

 12 35 7409.500 

 

Kruskal-Wallis Test Statistic = 108.868 

Probability is 0.000 assuming Chi-square distribution with 11 df 

Kruskal-Wallis One-Way Analysis of Variance for 435 cases 

Dependent variable is TN 

 Grouping variable is MONTH 

 

 Group Count Rank Sum 

 

 1 37 6797.000 

 2 45 8781.000 

 3 33 7424.500 

 4 35 6221.500 

 5 39 5920.500 

 6 37 6550.500 

 7 33 8281.500 

 8 41 11510.500 

 9 38 9532.000 

 10 31 9297.500 

 11 35 9272.000 

 12 31 5241.500 

 

Kruskal-Wallis Test Statistic = 60.474 

Probability is 0.000 assuming Chi-square distribution with 11 df 

Florida Department of Environmental Protection 

63
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Kruskal-Wallis One-Way Analysis of Variance for 459 cases 

Dependent variable is TP 

 Grouping variable is MONTH 

 

 Group Count Rank Sum 

 

 1 37 5820.500 

 2 46 5747.500 

 3 34 6059.000 

 4 38 8386.000 

 5 42 10459.000 

 6 38 11140.500 

 7 34 10831.000 

 8 41 13389.000 

 9 38 9129.000 

 10 38 11002.500 

 11 38 8048.500 

 12 35 5557.500 

 

Kruskal-Wallis Test Statistic = 110.555 

Probability is 0.000 assuming Chi-square distribution with 11 df 

Florida Department of Environmental Protection 

64
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Appendix E: Chart of DO, DOSAT, Corrected Chla, TN, and TP 

Observations by Season, Station, and Year in Spruce 

Creek 

CEN 27010193CEN 27010194CEN 27010195CEN 27010196CEN 27010197

SJWMSPRCR

SJWMUEC014

VEMDSC01VEMDSC02VEMDSC04VEMDSC05

VEMDVC-071VEMDVC-072VEMDVC-073VEMDVC-074

WPB 20010737WPB 20010738

STATION

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

10.5

11.0

11.5

12.0

D

SI S

O

L

V

E

D

O

X

Y

G

E

N (M

G/L)

WINTER

SUMMER

SPRING

FALL

SEASON

CEN 27010193CEN 27010194CEN 27010195CEN 27010196CEN 27010197

SJWMSPRCR

SJWMUEC014

VEMDSC01VEMDSC02VEMDSC04VEMDSC05

VEMDVC-071VEMDVC-072VEMDVC-073VEMDVC-074

WPB 20010737WPB 20010738

STATION

0

7

14

21

28

35

42

49

56

63

70

77

84

91

98

105

112

119

126

133

140

D

O

S

A

T

%( )

WINTER

SUMMER

SPRING

FALL

SEASON

Florida Department of Environmental Protection 

65
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

CEN 27010193CEN 27010194CEN 27010195CEN 27010196CEN 27010197

SJWMSPRCR

SJWMUEC014

VEMDSC01VEMDSC02VEMDSC04VEMDSC05

VEMDVC-071VEMDVC-072VEMDVC-073VEMDVC-074

WPB 20010737WPB 20010738

STATION

0.0

4.5

9.0

13.5

18.0

22.5

27.0

31.5

36.0

40.5

45.0

49.5

54.0

58.5

63.0

67.5

72.0

76.5

81.0

85.5

90.0

C

O

R

R

C

H

L

A

U( G/L)

WINTER

SUMMER

SPRING

FALL

SEASON

CEN 27010193CEN 27010194CEN 27010195CEN 27010196CEN 27010197

SJWMSPRCR

SJWMUEC014

VEMDSC01VEMDSC02VEMDSC04VEMDSC05

VEMDVC-071VEMDVC-072VEMDVC-073VEMDVC-074

WPB 20010737WPB 20010738

STATION

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

2.2

2.4

2.6

2.8

3.0

3.2

3.4

3.6

3.8

4.0

T

O

T

A

L

N

TI R

O

G

E

N (M

G/L)

WINTER

SUMMER

SPRING

FALL

SEASON

Florida Department of Environmental Protection 

66
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

CEN 27010193CEN 27010194CEN 27010195CEN 27010196CEN 27010197

SJWMSPRCR

SJWMUEC014

VEMDSC01VEMDSC02VEMDSC04VEMDSC05

VEMDVC-071VEMDVC-072VEMDVC-073VEMDVC-074

WPB 20010737WPB 20010738

STATION

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.65

0.70

0.75

0.80

0.85

0.90

0.95

1.00

T

O

T

A

L

P

H

O

S

P

H

O

R

U

S

M( G

L/ )

WINTER

SUMMER

SPRING

FALL

SEASON

199019911992199319941995199619971998199920002001200220032004200520062007

YEAR

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

10.5

11.0

11.5

12.0

D

SI S

O

L

V

E

D

O

X

Y

G

E

N

M( G

L/ )

Florida Department of Environmental Protection 

67
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

199019911992199319941995199619971998199920002001200220032004200520062007

YEAR

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100

105

110

115

120

125

130

D

O

S

A

T

%( )

199019911992199319941995199619971998199920002001200220032004200520062007

YEAR

0

3

6

9

12

15

18

21

24

27

30

33

36

39

42

45

48

51

54

57

60

63

66

69

72

75

78

81

84

87

90

C

O

R

R

C

H

L

A (U

G

L/ )

Florida Department of Environmental Protection 

68
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

199019911992199319941995199619971998199920002001200220032004200520062007

YEAR

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

2.2

2.4

2.6

2.8

3.0

3.2

3.4

3.6

3.8

4.0

T

O

T

A

L

N

TI R

O

G

E

N

M( G/L)

199019911992199319941995199619971998199920002001200220032004200520062007

YEAR

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.65

0.70

0.75

0.80

0.85

0.90

0.95

1.00

T

O

T

A

L

P

H

O

S

P

H

O

R

U

S

M( G

L/ )

Florida Department of Environmental Protection 

69
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

0.00.40.81.21.62.02.42.83.23.64.04.44.85.25.66.06.46.87.27.68.08.48.89.29.6

10.0

DISSOLVED OXYGEN (MG/L)

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.65

0.70

0.75

0.80

0.85

0.90

0.95

1.00

F

R

A

C

T

OI N

O

F

D

A

T

A

0 5

101520253035404550556065707580859095

100105110115120125130

DOSAT (%)

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.65

0.70

0.75

0.80

0.85

0.90

0.95

1.00

F

R

A

C

T

OI N

O

F

D

A

T

A

Florida Department of Environmental Protection 

70
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

0 3 6 9

121518212427303336394245485154576063666972757881848790

CORR CHLA (UG/L)

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.65

0.70

0.75

0.80

0.85

0.90

0.95

1.00

F

R

A

C

T

OI N

O

F

D

A

T

A

0.00.20.40.60.81.01.21.41.61.82.02.22.42.62.83.03.23.43.63.84.0

TOTAL NITROGEN (MG/L)

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.65

0.70

0.75

0.80

0.85

0.90

0.95

1.00

F

R

A

C

T

OI N

O

F

D

A

T

A

Florida Department of Environmental Protection 

71
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

0.000.040.080.120.160.200.240.280.320.360.400.440.480.520.560.600.640.680.720.760.800.840.880.920.961.00

TOTAL PHOSPHORUS (MG/L)

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.65

0.70

0.75

0.80

0.85

0.90

0.95

1.00

F

R

A

C

TIO

N

O

F

D

A

T

A

DO VERSUS SAMPLING DATE

y = 0.0002x - 0.818

R2

 = 0.0141

0

2

4

6

8

10

12

9/19/19911/31/19936/15/1994

10/28/1995

3/11/19977/24/199812/6/19994/19/2001

9/1/2002

1/14/20045/28/2005

10/10/2006

2/22/2008

SAMPLE DATE

DISSOLVED OXYGEN 

(MG/L)

Florida Department of Environmental Protection 

72
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

CORR CHLA VERSUS SAMPLING DATE

y = -0.0003x + 18.666

R2

 = 0.0006

0

10

20

30

40

50

60

70

80

90

100

9/19/1991

1/31/19936/15/1994

10/28/1995

3/11/1997

7/24/1998

12/6/1999

4/19/2001

9/1/2002

1/14/20045/28/2005

10/10/2006

2/22/2008

SAMPLE DATE

CORR CHLA (UG/L)

TN VERSUS SAMPLING DATE

y = -0.0002x + 6.361

R2

 = 0.1233

0

0.5

1

1.5

2

2.5

3

3.5

4

9/19/1991

1/31/19936/15/1994

10/28/1995

3/11/1997

7/24/1998

12/6/19994/19/2001

9/1/2002

1/14/20045/28/2005

10/10/2006

2/22/2008

SAMPLE DATE

TOTAL NITROGEN (MG/L)

Florida Department of Environmental Protection 

73
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

TP VERSUS SAMPLING DATE

y = -6E-06x + 0.3858

R2 = 0.006

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

9/19/19911/31/1993

6/15/1994

10/28/1995

3/11/19977/24/199812/6/19994/19/2001

9/1/2002

1/14/20045/28/2005

10/10/2006

2/22/2008

SAMPLE DATE

TOTAL PHOSPHORUS 

(MG/L)

STORET ID Station 

21FLVEMDSC01 Spruce Creek Center Bridge on U.S. Hwy 1 

21FLVEMDSC02 Spruce Creek West of SSC Railroad 

21FLVEMDSC04 Spruce Creek West of Airport Rd 

21FLVEMDSC05 Spruce Creek at Dock at Gamble Place 

21FLSJWMSPRCR Spruce Creek 100 M Upstream from ICWW 

21FLSJWMUEC014 Spruce Creek at Airport Rd 

21FLVEMDVC-071 Spruce Creek, from W Side of Center Bridge on U.S. 1 

21FLVEMDVC-072 Spruce Creek, from Dock at Riverwood, W. of SCL Railroad 

21FLVEMDVC-073 Spruce Creek, from W. Side of Moody Bridge on Airport Rd 

21FLVEMDVC-074 Spruce Creek, from Dock at Gamble Place 

21FLWPB 20010737 Spruce Creek @ Cypress Head Development 

21FLWPB 20010738 Spruce Creek @ Airport Rd 

21FLCEN 27010193 Spruce Creek @ 675M Upstream of RR Bridge 

21FLCEN 27010194 Spruce Creek @ 0.68 Miles Upstream of RR Bridge 

21FLCEN 27010195 Spruce Creek @ 0.87 Miles Upstream of RR Bridge 

21FLCEN 27010196 Spruce Creek @ 1.07 Miles Upstream of RR Bridge 

21FLCEN 27010197 Spruce Creek @ 1.3 Miles Upstream of RR Bridge 

Florida Department of Environmental Protection 

74
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Appendix F: Chart of Rainfall for Daytona International Airport, 1948–

2006 

DAYTONA BEACH INTERNATIONAL AIRPORT 

RAINFALL 1948 - 2006

0.00

2.00

4.00

6.00

8.00

10.00

1/1/19481/1/19521/1/19561/1/19601/1/19641/1/19681/1/19721/1/19761/1/19801/1/19841/1/19881/1/19921/1/19961/1/20001/1/2004

DATE

RAINFALL (INCHES)

Florida Department of Environmental Protection 

75
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Appendix G: Spearman Correlation Matrix Analysis for Water Quality 

Parameters in Spruce Creek 

Spearman correlation matrix 

DATE2 TIME DEPTH DO DOSAT 

DATE2 1.000 

TIME 0.284 1.000 

DEPTH -0.036 -0.049 1.000 

DO 0.087 0.419 -0.157 1.000 

DOSAT 0.257 0.501 -0.257 0.918 1.000 

CHLA 0.066 0.186 -0.074 -0.097 0.076 

CHLAC -0.044 0.099 -0.076 -0.152 0.001 

TN -0.401 -0.266 -0.060 -0.184 -0.253 

TP -0.065 -0.280 0.061 -0.478 -0.440 

COLOR -0.016 -0.272 0.119 -0.244 -0.373 

TEMP 0.053 -0.015 -0.016 -0.412 -0.145 

NH4 -0.366 -0.361 0.239 -0.422 -0.538 

NO3O2 -0.087 -0.128 0.114 -0.142 -0.276 

SECCHI -0.025 0.160 0.149 0.094 0.114 

TKN -0.430 -0.274 -0.059 -0.188 -0.251 

BOD -0.175 -0.113 -0.242 -0.847 0.200 

TSS -0.050 0.358 -0.116 0.321 0.476 

ORTHOP -0.135 -0.404 -0.005 -0.523 -0.547 

TURBIDITY 0.128 0.076 -0.071 0.069 0.163 

SALINITY 0.019 0.384 -0.143 0.368 0.528 

FLOWCFS 0.020 -0.012 -0.029 0.131 0.037 

FLOW3DAYAVE 0.045 -0.017 -0.012 0.125 0.038 

PRECIP -0.030 -0.046 0.086 -0.089 -0.069 

RAINDAY3 0.065 -0.057 -0.003 -0.089 -0.080 

CHLA CHLAC TN TP COLOR 

CHLA 1.000 

CHLAC 0.950 1.000 

TN -0.272 -0.170 1.000 

TP 0.073 0.176 0.263 1.000 

COLOR -0.437 -0.391 0.594 0.194 1.000 

TEMP 0.564 0.532 0.048 0.401 -0.138 

NH4 0.471 0.006 0.322 0.219 0.001 

NO3O2 -0.285 -0.266 0.326 0.063 0.517 

SECCHI 0.268 0.239 -0.539 -0.112 -0.670 

TKN -0.241 -0.124 0.992 0.263 0.524 

BOD . 0.300 0.644 0.483 . 

TSS 0.475 0.390 -0.278 -0.053 -0.610 

ORTHOP -0.083 -0.003 0.456 0.675 0.534 

TURBIDITY 0.137 0.086 0.085 0.222 -0.040 

SALINITY 0.439 0.360 -0.557 -0.225 -0.844 

FLOWCFS -0.431 -0.395 0.447 0.088 0.644 

FLOW3DAYAVE -0.431 -0.385 0.442 0.092 0.642 

PRECIP 0.103 0.053 -0.008 0.162 0.045 

RAINDAY3 -0.073 -0.099 0.082 0.266 0.194 

Florida Department of Environmental Protection 

76
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Spearman correlation matrix (continued)

TEMP NH4 NO3O2 SECCHI TKN 

TEMP 1.000 

NH4 -0.033 1.000 

NO3O2 -0.287 0.528 1.000 

SECCHI 0.021 -0.245 -0.267 1.000 

TKN 0.080 0.258 0.232 -0.514 1.000 

BOD 0.671 -0.004 -0.088 -0.574 0.869 

TSS 0.328 -0.160 -0.371 0.258 -0.206 

ORTHOP 0.309 0.179 0.307 -0.346 0.405 

TURBIDITY 0.198 0.047 0.019 -0.222 0.108 

SALINITY 0.199 -0.438 -0.493 0.536 -0.482 

FLOWCFS -0.118 -0.062 0.349 -0.559 0.379 

FLOW3DAYAVE -0.097 -0.058 0.330 -0.534 0.378 

PRECIP 0.150 0.054 -0.009 -0.059 -0.010 

RAINDAY3 0.104 -0.153 0.068 -0.256 0.069 

BOD TSS ORTHOP TURBIDITY SALINITY 

BOD 1.000 

TSS . 1.000

ORTHOP . -0.340 1.000

TURBIDITY . 0.492 0.097 1.000

SALINITY 0.763 0.726 -0.523 0.129 1.000 

FLOWCFS 0.541 -0.215 0.325 0.105 -0.441 

FLOW3DAYAVE 0.483 -0.232 0.314 0.072 -0.451 

PRECIP -0.242 0.123 0.134 0.073 -0.025 

RAINDAY3 0.582 0.019 0.349 0.166 -0.143 

FLOWCFS FLOW3DAYAVE PRECIP RAINDAY3 

FLOWCFS 1.000

FLOW3DAYAVE 0.969 1.000

PRECIP 0.079 0.017 1.000

RAINDAY3 0.408 0.342 0.507 1.000 

Florida Department of Environmental Protection 

77
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Pair-wise frequency table 

DATE2 TIME DEPTH DO DOSAT 

DATE2 538 

TIME 534 534 

DEPTH 528 528 528 

DO 492 492 486 492 

DOSAT 481 481 475 481 481 

CHLA 300 300 296 264 264 

CHLAC 459 459 455 421 414 

TN 435 435 431 401 394 

TP 459 455 454 419 412 

COLOR 490 490 484 449 449 

TEMP 498 498 492 492 481 

NH4 68 68 66 68 61 

NO3O2 481 481 477 442 435 

SECCHI 463 463 458 423 412 

TKN 464 460 455 425 418 

BOD 27 27 27 27 16 

TSS 439 435 430 399 399 

ORTHOP 399 399 399 362 362 

TURBIDITY 453 449 443 413 413 

SALINITY 449 449 449 444 444 

FLOWCFS 538 534 528 492 481 

FLOW3DAYAVE 538 534 528 492 481 

PRECIP 538 534 528 492 481 

RAINDAY3 538 534 528 492 481 

CHLA CHLAC TN TP COLOR 

CHLA 300 

CHLAC 299 459 

TN 265 410 435 

TP 273 428 430 459 

COLOR 294 437 421 436 490 

TEMP 267 424 401 420 454 

NH4 13 55 56 60 51 

NO3O2 289 435 435 434 459 

SECCHI 287 401 381 391 426 

TKN 274 432 435 457 442 

BOD 0 15 12 15 0 

TSS 264 407 410 429 432 

ORTHOP 266 356 348 360 393 

TURBIDITY 277 421 423 442 446 

SALINITY 244 388 360 382 417 

FLOWCFS 300 459 435 459 490 

FLOW3DAYAVE 300 459 435 459 490 

PRECIP 300 459 435 459 490 

RAINDAY3 300 459 435 459 490 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Pair-wise frequency table (continued) 

TEMP NH4 NO3O2 SECCHI TKN 

TEMP 498 

NH4 68 68 

NO3O2 445 61 481 

SECCHI 429 25 426 463 

TKN 425 63 438 394 464 

BOD 27 15 12 25 15 

TSS 399 36 416 383 436 

ORTHOP 365 36 386 351 362 

TURBIDITY 413 48 429 384 449 

SALINITY 449 41 404 399 382 

FLOWCFS 498 68 481 463 464 

FLOW3DAYAVE 498 68 481 463 464 

PRECIP 498 68 481 463 464 

RAINDAY3 498 68 481 463 464 

 BOD TSS ORTHOP TURBIDITY SALINITY

BOD 27

TSS 0 439

ORTHOP 0 363 399

TURBIDITY 0 439 364 453

SALINITY 16 375 346 376 449

FLOWCFS 27 439 399 453 449

FLOW3DAYAVE 27 439 399 453 449

PRECIP 27 439 399 453 449

RAINDAY3 27 439 399 453 449

FLOWCFS FLOW3DAYAVE PRECIP RAINDAY3

FLOWCFS 538

FLOW3DAYAVE 538 538

PRECIP 538 538 538

RAINDAY3 538 538 538 538

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Appendix H: Linear Regression Analysis of DO and Corrected Chla 

Observations versus Nutrients and BOD in Spruce Creek 

Dep Var: DO N: 419 Multiple R: 0.422 Squared multiple R: 0.178 

 

Adjusted squared multiple R: 0.177 Standard error of estimate: 1.909 

Effect Coefficient Std Error Std Coef Tolerance t P(2 Tail) 

CONSTANT 6.389 0.188 0.000 . 34.027 0.000 

TP -8.941 0.939 -0.422 1.000 -9.518 0.000 

 

Analysis of Variance 

Source Sum-of-Squares df Mean-Square F-ratio P 

Regression 330.273 1 330.273 90.600 0.000

Residual 1520.124 417 3.645

*** WARNING *** 

Case 75 has large leverage (Leverage = 0.067) 

Case 95 has large leverage (Leverage = 0.060) 

Case 141 has large leverage (Leverage = 0.049) 

Case 151 has large leverage (Leverage = 0.052) 

Case 326 has large leverage (Leverage = 0.055) 

 

Durbin-Watson D Statistic 1.581 

First Order Autocorrelation 0.204 

Dep Var: DO N: 401 Multiple R: 0.109 Squared multiple R: 0.012 

 

Adjusted squared multiple R: 0.009 Standard error of estimate: 2.090 

Effect Coefficient Std Error Std Coef Tolerance t P(2 Tail) 

CONSTANT 5.220 0.230 0.000 . 22.674 0.000

TN -0.438 0.201 -0.109 1.000 -2.180 0.030

 

Analysis of Variance 

Source Sum-of-Squares df Mean-Square F-ratio P 

Regression 20.764 1 20.764 4.754 0.030

Residual 1742.565 399 4.367

*** WARNING *** 

Case 45 has large leverage (Leverage = 0.046) 

Case 46 has large leverage (Leverage = 0.046) 

Case 153 has large leverage (Leverage = 0.066) 

 

Durbin-Watson D Statistic 1.465 

First Order Autocorrelation 0.263 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Dep Var: DO N: 421 Multiple R: 0.145 Squared multiple R: 0.021 

 

Adjusted squared multiple R: 0.019 Standard error of estimate: 2.089 

Effect Coefficient Std Error Std Coef Tolerance t P(2 Tail) 

CONSTANT 4.917 0.108 0.000 . 45.608 0.000

CHLAC -0.016 0.005 -0.145 1.000 -3.001 0.003

 

Analysis of Variance 

Source Sum-of-Squares df Mean-Square F-ratio P 

Regression 39.303 1 39.303 9.006 0.003

Residual 1828.584 419 4.364

*** WARNING *** 

Case 226 has large leverage (Leverage = 0.348) 

Case 351 has large leverage (Leverage = 0.446) 

 

Durbin-Watson D Statistic 1.452 

First Order Autocorrelation 0.270 

Dep Var: DO N: 68 Multiple R: 0.547 Squared multiple R: 0.299 

 

Adjusted squared multiple R: 0.289 Standard error of estimate: 1.509 

Effect Coefficient Std Error Std Coef Toleranc

e 

t P(2 Tail) 

CONSTANT 5.658 0.284 0.000 . 19.898 0.000

NH4 -18.990 3.578 -0.547 1.000 -5.307 0.000

 

Analysis of Variance 

Source Sum-of-Squares df Mean-Square F-ratio P 

Regression 64.109 1 64.109 28.168 0.000

Residual 150.211 66 2.276

*** WARNING *** 

Case 17 has large leverage (Leverage = 0.176) 

Case 456 has large leverage (Leverage = 0.177) 

 

Durbin-Watson D Statistic 1.560 

First Order Autocorrelation 0.146 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Dep Var: DO1 N: 27 Multiple R: 0.828 Squared multiple R: 0.685 

 

Adjusted squared multiple R: 0.672 Standard error of estimate: 0.632 

Effect Coefficient Std Error Std Coef Tolerance t P(2 Tail) 

CONSTANT 6.938 0.258 0.000 . 26.842 0.000

BOD -0.892 0.121 -0.828 1.000 -7.371 0.000

 

Analysis of Variance 

Source Sum-of-Squares df Mean-Square F-ratio P 

Regression 21.692 1 21.692 54.327 0.000

Residual 9.982 25 0.399

*** WARNING *** 

Case 466 is an outlier (Studentized Residual = -4.093) 

 

Durbin-Watson D Statistic 1.624 

First Order Autocorrelation 0.165 

Dep Var: DO N: 442 Multiple R: 0.086 Squared multiple R: 0.007 

 

Adjusted squared multiple R: 0.005 Standard error of estimate: 2.086 

Effect Coefficient Std Error Std Coef Tolerance t P(2 Tail) 

CONSTANT 5.014 0.150 0.000 . 33.524 0.000

NO3O2 -2.801 1.555 -0.086 1.000 -1.801 0.072

 

Analysis of Variance 

Source Sum-of-Squares df Mean-Square F-ratio P 

Regression 14.112 1 14.112 3.244 0.072

Residual 1913.820 440 4.350

*** WARNING *** 

Case 215 has large leverage (Leverage = 0.129) 

Case 279 has large leverage (Leverage = 0.084) 

 

Durbin-Watson D Statistic 1.368 

First Order Autocorrelation 0.313 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Dep Var: CHLAC N: 428 Multiple R: 0.036 Squared multiple R: 0.001 

 

Adjusted squared multiple R: 0.000 Standard error of estimate: 18.871 

Effect Coefficient Std Error Std Coef Tolerance t P(2 Tail) 

CONSTANT 5.560 1.808 0.000 . 3.076 0.002

TP 6.556 8.877 0.036 1.000 0.738 0.461

 

Analysis of Variance 

Source Sum-of-Squares df Mean-Square F-ratio P 

Regression 194.209 1 194.209 0.545 0.461

Residual 151699.350 426 356.102

*** WARNING *** 

Case 75 has large leverage (Leverage = 0.061) 

Case 90 is an outlier (Studentized Residual = 3.985) 

Case 95 has large leverage (Leverage = 0.054) 

Case 141 has large leverage (Leverage = 0.044) 

Case 151 has large leverage (Leverage = 0.047) 

Case 226 is an outlier (Studentized Residual = 14.825) 

Case 326 has large leverage (Leverage = 0.050) 

Case 351 is an outlier (Studentized Residual = 18.093) 

 

Durbin-Watson D Statistic 1.975 

First Order Autocorrelation 0.011 

Dep Var: CHLAC N: 435 Multiple R: 0.052 Squared multiple R: 0.003 

 

Adjusted squared multiple R: 0.000 Standard error of estimate: 18.724 

Effect Coefficient Std Error Std Coef Tolerance t P(2 Tail) 

CONSTANT 7.624 1.336 0.000 . 5.705 0.000

NO3O2 -15.558 14.431 -0.052 1.000 -1.078 0.282

 

Analysis of Variance 

Source Sum-of-Squares df Mean-Square F-ratio P 

Regression 407.482 1 407.482 1.162 0.282

Residual 151797.347 433 350.571

*** WARNING *** 

Case 90 is an outlier (Studentized Residual = 4.032) 

Case 215 has large leverage (Leverage = 0.140) 

Case 226 is an outlier (Studentized Residual = 14.834) 

Case 279 has large leverage (Leverage = 0.091) 

Case 351 is an outlier (Studentized Residual = 18.322) 

 

Durbin-Watson D Statistic 1.967 

First Order Autocorrelation 0.015 

Florida Department of Environmental Protection 

83
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Dep Var: CHLAC N: 55 Multiple R: 0.014 Squared multiple R: 0.000 

 

Adjusted squared multiple R: 0.000 Standard error of estimate: 7.675 

Effect Coefficient Std Error Std Coef Tolerance t P(2 Tail) 

CONSTANT 6.460 1.527 0.000 . 4.231 0.000

NH4 1.925 19.297 0.014 1.000 0.100 0.921

 

Analysis of Variance 

Source Sum-of-Squares df Mean-Square F-ratio P 

Regression 0.586 1 0.586 0.010 0.921

Residual 3122.352 53 58.912

*** WARNING *** 

Case 17 has large leverage (Leverage = 0.205) 

Case 443 is an outlier (Studentized Residual = 4.014) 

Case 456 has large leverage (Leverage = 0.206) 

 

Durbin-Watson D Statistic 2.040 

First Order Autocorrelation -0.083 

Dep Var: CHLAC N: 428 Multiple R: 0.036 Squared multiple R: 0.001 

 

Adjusted squared multiple R: 0.000 Standard error of estimate: 18.871 

Effect Coefficient Std Error Std Coef Tolerance t P(2 Tail) 

CONSTANT 5.560 1.808 0.000 . 3.076 0.002

TP 6.556 8.877 0.036 1.000 0.738 0.461

 

Analysis of Variance 

Source Sum-of-Squares df Mean-Square F-ratio P 

Regression 194.209 1 194.209 0.545 0.461

Residual 151699.350 426 356.102

*** WARNING *** 

Case 75 has large leverage (Leverage = 0.061) 

Case 90 is an outlier (Studentized Residual = 3.985) 

Case 95 has large leverage (Leverage = 0.054) 

Case 141 has large leverage (Leverage = 0.044) 

Case 151 has large leverage (Leverage = 0.047) 

Case 226 is an outlier (Studentized Residual = 14.825) 

Case 326 has large leverage (Leverage = 0.050) 

Case 351 is an outlier (Studentized Residual = 18.093) 

 

Durbin-Watson D Statistic 1.975 

First Order Autocorrelation 0.011 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Appendix I: Monthly and Annual Precipitation at Daytona International 

Airport, 1948–2006 

Year(s) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual 

Totals 

1948 4.52 1.22 5.13 2.37 0.49 2.4 10.43 7.33 9.82 8.29 1.07 1.93 55 

1949 0.37 1.95 2.01 7.12 1.4 4.24 5.97 11.5 6.26 3.65 1.86 3.93 50.22 

1950 0.15 0.59 3.53 2.79 2.13 6.45 5.56 3.88 5.86 13 0.74 2.54 47.22 

1951 0.77 2.46 1.18 3.28 2.53 2.66 3.8 4.19 14 8.54 3.15 2.88 49.46 

1952 0.66 6.76 3.01 1.66 4.39 1.35 1.25 9.02 11.9 5.41 1.96 0.71 48.1 

1953 1.75 3.35 7.75 4.97 1.46 1.37 8.67 19.9 10 12.9 2.3 4.85 79.29 

1954 0.37 0.86 2.33 6.29 3.21 2.35 3.5 3.04 1.88 4.91 3.98 1.24 33.96 

1955 2.47 1.43 1.84 1.78 1.55 7.76 5.67 2.64 6.66 3.17 2.61 1.22 38.8 

1956 2.55 0.9 0.25 2.42 2.48a 7.41 3.01 4.06 1.94 5.82 0.46 0.06 31.36 

1957 0.97 1.62 3.13 1.73 5.65 4.23 10.53 4.01 10.7 1.8 0.82 1.34 46.48 

1958 3.94 4.73 5.52 2.24 2.27 6.06 1.96 4 2.19 8.52 1.77 1.95 45.15 

1959 4.53 2.13 7.7 3.17 2.4 8.13 5.68 3.6 5.26 7.12 4.26 2.26 56.24 

1960 1.16 9.13 7.52 0.76 0.62 10.8 8.7 6.84 11 0.97 0.53 1.24 59.18 

1961 1.96 3.7 1.17 2.16 2.39 6.81 5.16 7.68 3.2 2.25 2.85 0.73 40.06 

1962 0.9 0.82 1.82 0.78 0.16 7.96 10.04 8.5 8.84 3.57 2.49 0.71 46.59 

1963 2.91 5.83 1.46 1.4 6.82 7.42 6.89 2.01 5.43 2.71 7.98 2.17 53.03 

1964 5.29 2.65 4.84 3.61 2.58 4.73 7.67 10.8 11.4 3.54 3.13 2.52 62.76 

1965 2.22 3 3.05 1 0.08 9 3.72 2.97 4.33 3.65 0.97 2.14 36.13 

1966 2.89 5.58 0.36 2.56 6.77 15.2 7.09 7.93 4.49 4.6 1.19 1.6 60.25 

1967 1.26 3.98 0.31 0 0.73 7.51 9.04 3.02 5.56 0.19 0 2.98 34.58 

1968 0.42 1.73 1.79 0.4 4.79 14.4 6.25 11.1 6.07 7.44 2.43 1.38 58.17 

1969 1.53 2.03 2.74 0.12 6.47 2.47 2.61 9.4 8.89 6.97 1.96 5.03 50.22 

1970 3.94 3.79 3.59 2.08 1.68 2.62 3.65 3.61 3.54 3.87 0.31 0.72 33.4 

1971 0.61 5.48 2 2.57 3.12 4.73 3.2 3.97 7.2 9.53 1.33 2.49 46.23 

1972 2.37 3.97 6.66 1.41 4.02 7.06 3.22 8.29 0.42 3.08 10.96 2.48 53.94 

1973 4.66 2.02 2.63 3.09 2.41 4.32 4.69 7.58 5.14 4.4 0.75 2.54 44.23 

1974 0.3 1.1 3.19 0.44 2.66 8.65 6.31 9.96 10.5 1.42 0.48 2.2 47.21 

1975 1.66 2.27 1.52 2.96 2.99 9 6.89 3.16 6.61 5.84 1.46 0.83 45.19 

1976 0.6 0.7 2.03 4.27 12.33 11.1 1.07 3.8 5.1 1.9 3.38 6 52.32 

1977 4.69 2.45 1.43 0.41 4.61 1.15 2.23 7.91 6.55 1.46 3.04 4.74 40.67 

1978 2.89 5.98 2.31 3.3 0.56 7.48 5.53 7.99 4.63 8.31 0.07 4.89 53.94 

1979 7.1 1.94 4.08 3.96 6.13 3.03 11.69 5.24 15.2 2.13 7.96 0.56 69.02 

1980 3.75 0.76 2.41 2.54 3.62 5.57 5.82 4.13 1.83 2.42 3.12 1.39 37.36 

1981 0.32 5.54 3 0.29 1.74 1.03 4.69 7.19 7.59 1.08 2.57 4.64 39.68 

1982 2.46 2.08 5.81 6.04 4.68 8.29 5.31 3.21 4.96 3.23 1.58 2.53 50.18 

1983 2.51 5.96 7.71 6.17 3.86 6.37 1.92 6.82 8.57 10.1 2.01 12 73.99 

1984 1.46 3.44 1.31 5.29 6.04 2.84 6.77 4.02 10.7 1.09 3.52 0.2 46.71 

1985 0.79 0.58 1.49 3.14 3.42 6.81 2.16 9.83 10.6 4.08 0.41 2.05 45.38 

1986 7.16 1.28 1.85 0.44 0.99 3.5 14.43 3.47 3.58 3.47 5.08 2.76 48.01 

1987 2.21 6.64 7.94 0.28 2.65 3.81 2.78 4.89 5.63 2.77 5.87 0.25 45.72 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Annual Year(s) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Totals 

1988 5.36 1.72 4.57 1.68 1.78 2.39 2.94 4.79 6.81 1.24 6.7 0.93 40.91 

1989 6.82 0.64 2.01 2.92 2.02 1.84 2.44 4.47 5.04 11.6 0.88 3.93 44.65 

1990 1.42 5.61 1.94 1.48 1.45 2.71 5.85 7 1.61 5.88 0.83 0.34 36.12 

1991 2.25 1.65 8.11 5.57 6.79 12.7 11.97 7.6 5.52 2.94 0.61 1.51 67.19 

1992 2.42 1.71 2.28 2.81 3.13 10.6 0.16 8.86 6.57 5.21 2.15 0.47 46.41 

1993 4.29 3.02 5.56 0.33 0.65 2.19 5.05 2.66 2.74 5.53 1.83 1.86 35.71 

1994 5.6 2.66 3.44 5.05 3.09 6.54 6.91 7.08 5.93 4.72 12.91 2.71 66.64 

1995 1.53 1.39 2.01 1.34 1.26 6.61 6.59 10.7 14.1 3.99 1.44 3.44 54.44 

1996 5.53 1.32 12.15 2.22 2.28 11.4 1.9 5.7 3.92 11.2 0.96 2.01 60.49 

1997 2.03 0.46 2.3 3.3 3.77 6.38 7.69 7.91 4.78 5.29 3.02 7.76 54.69 

1998 4.33 7.25 3.97 0.14 0.16 0.83 5.63 7.56 5.79 1.84 1.66 1.35 40.51 

1999 4.88 1.81 1.01 1.48 1.47 8.54 4.03 3.58 7.05 7.84 3.12 1.56 46.37 

2000 1.8 0.65 8.48 1.15 0.32 3.08 5.09 3.17 13.6 0.93 1.14 0.8 40.16 

2001 0.88 0.38 9.98 0.28 1.77 5.26 9.55 3.57 16.1 3.22 6.92 0.35 58.27 

2002 2.01 2.76 1.51 2.53 1.66 12.3 7.35 11.6 3.86 2.94 1.85 9.61 59.94 

2003 0.51 5.17 10.57 0.81 0.96 7.05 7.3 6.55 4.15 7.95 4.75 1.53 57.3 

2004 1.25 4.47 1.1 1.19 0.49 5.2 10.34 18 16.5 1.34 0.93 2.24 62.97 

2005 2.6 1.25 5.51 3.17 7.97 13.7 2.73 4.29 7.35 13.5 1.87 1.85 65.77 

2006 0.24 4.33 0.08 1.11 0.78 5.72 4.48 4.81 2.97 2.53 1.1 3.21 31.36 

Max 

value 7.16 9.13 12.15 7.12 12.33 15.2 14.43 19.9 16.5 13.5 12.91 12 79.29 

Min 

value 0.15 0.38 0.08 0 0.08 0.83 0.16 2.01 0.42 0.19 0 0.06 31.36 

Mean 2.52 2.89 3.66 2.37 2.89 6.15 5.65 6.48 6.92 4.9 2.66 2.48 49.58 

Median 2.21 2.13 2.63 2.22 2.4 6.37 5.56 5.7 5.93 3.87 1.87 2.01 47.22 

# years 59 59 59 59 59 59 59 59 59 59 59 59 59 

FLAGS: a = 1, b = 2, c = 3, ..., or z = 26 or more missing days 

Rainfall is in inches, and represents data from Daytona Beach International Airport. 

Florida Department of Environmental Protection 

86
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Appendix J: Annual and Monthly Average Precipitation at Daytona 

International Airport 

DIA ANNUAL RAINFALL

0

10

20

30

40

50

60

70

80

90

19481951195419571960196319661969197219751978198119841987199019931996199920022005

YEAR

RAINFALL (INCHES)

LONG-TERM AVERAGE

MONTHLY AVERAGE RAINFALL

0

1

2

3

4

5

6

7

8

JAN 

 FEB 

 MAR 

 APR 

 MAY 

JUN 

 JUL

 AUG

SEP

 OCT 

 NOV 

 DEC 

MONTH

RAINFALL (INCHES)

MONTHLY AVERAGE

Florida Department of Environmental Protection 

87
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Appendix K: Response to Comments Following the January 15, 2008 

Public Meeting 

Florida Department of Environmental Protection 

88
Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Response to comments on the TMDL for Nutrients and Dissolved Oxygen: WBID 2674A 

Comment 1. Following the January 15, 2008 public workshop, Ms. Kelly Young of the Volusia County 

Environmental Health Laboratory provided a spreadsheet of water quality data collected in this WBID. 

The Department had not assigned station VEMDVC – 071 to this WBID so information contained in 

Florida STORET from this station was not used in the original assessment or draft TMDL. With the 

exception of this station, data collected by the County that was part of Legacy STORET or Florida 

STORET was used. Data from this station along with some additional data that were not previously 

entered into STORET were incorporated into the present TMDL. As a result, the percent reduction in 

total phosphorus from anthropogenic sources changed from 32 to 27. 

Comment 2. Principal land uses illustrated in Figure 4.3 and summarized in Table 4.1 were 

based on the 2004 land use coverages provided to the Department from the St. Johns Water 

Management District and represent the most current coverage made available to the 

Department. The land use figure and table were presented to illustrate the general features of 

the watershed and were not used in the establishment of the TMDL. The percent reduction 

calculations were based upon water quality measurements taken at ambient stations located 

along Spruce Creek. Section 4.3 of the document identified Potential sources that might 

contribute nutrients and BOD to Spruce Creek. Acreage information from the land use 

summary was used to obtain estimates of potential nutrient contributions from these activities. 

As part of the BMAP process, updated and more detailed land use information could assist in 

further refining pollutant sources and cost effective measures to reduce these pollutants. 

Florida Department of Environmental Protection 

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Final TMDL Report: Spruce Creek, WBID 2674A, Upper East Coast Basin, Dissolved Oxygen and Nutrients 

Florida Department of Environmental Protection 

90

Comment 3. We agree that the linear regression between phosphorus and DO may reflect an 

indirect relationship, however, it does not mean that the TMDL should be delayed. Monitoring 

should be a component of the basin management action plan (BMAP), particularly as part of a 

more detailed source identification element and assessment of cost effective strategies to 

reduce nutrients and BOD contributions from anthropogenic activities in the watershed. This 

would provide an opportunity to test and confirm the relationship between DO and phosphorus 

concentrations and the system response to reductions in these pollutants as best management 

practices are implemented. 

 
Florida Department of Environmental Protection 

Division of Water Resource Management 

Bureau of Watershed Management 

2600 Blair Stone Road, Mail Station 3565 

Tallahassee, Florida 32399-2400 

www.dep.state.fl.us/water/