TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters



## Appendix B-17: FDEP’s Stre am Benchmark Summaries

(Appendix 7-A from USEPA. 2009. Proposed Methods and Approaches for Developing Numeric Nutrient Criteria for Florida’s Inland Waters . United States Environm ental Protection Agency, Office of Water, Office of Science and Technol ogy, Health and Ecological Criteria Division, Washington, DC.)TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-1 BONE VALLEY NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Deer Prairie Creek

STORET Station 27051558216422

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.57, suggesting benign human influences in the wa tershed. During the site visit, aerial photographs were examined and direct observations confirmed that the majo rity of the watershed land use was forest/natural, with small areas of agriculture and residential land use observed beyond an extensive forested riparian buffer zone. The majority of the watershed lies within conservation lands. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Deer Prairie Creek (Sta tion 27051558216422) showing watershed vicinity and

land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Deer Prairie Creek (Stati on 27051558216422) showing close-up of sampling site.

Photograph of Deer Prairie CreekTSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-2 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 117 Hydrologic Score 2

LDI Score 1.57

SCI Score 74 A Total Phosphorus Geometric Mean (mg/L) 0.285 Total Nitrogen Geometric Mean (mg/L) 1.14

The habitat assessment scored in the high end of the “Subop timal” range due to the low water levels. The Stream Condition Index scored in the “Exceptional” category, i ndicating an unusually diverse assemblage of sensitive invertebrates, fully supporting the Class III designation.

Periphyton Community Composition

Algal Community Stricture % Composition % Bacillariophyta 89.00 % Chlorophycota 0.33 % Cryptophycophyta 0 % Cyanophycota 10.67

Number of Taxa 51

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic invertebrate and fish communities. Of the 51 algal taxa observed, the majority of the periphyton community was composed of diatoms. No problematic filamentous algal growth was found.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communities) at Deer Prairie Creek. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assemblages. T hus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-3 BONE VALLEY NUTRIENT REGION

Nutrient Benchmark Site Summary



## East Fork Manatee River

STORET Station 273116508208152

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 2.22, suggesting relatively benign human influe nces in the watershed. During the site visit, aerial photographs were examined and direct observations confirmed that the majo rity of the watershed land use was forest/natural, with field/pasture located beyond a riparian buffer zone. Although there is phosphate mining in the area, no phosphate process water is discharged to the East fork of the Manatee River. The site is located within protected conservation lands.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of East Fork Manatee Ri ver (Station 273116508208152) showing watershed vicinity and land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of East Fork Manatee Ri ver (Station 273116508208152) showing close-up of sampling site.

Photograph of East Fork Manatee RiverTSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-4 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 128 Hydrologic Score 2

LDI Score 2.22

SCI Score 71 A Total Phosphorus Geometric Mean (mg/L) 0.417 Total Nitrogen Geometric Mean (mg/L) 1.04

The habitat assessment scored in the “Optimal” range, a nd the Stream Condition Index scored in the “Exceptional” category, indicating an unusually diverse assemblage of sensitive invertebrates, definitively supporting the Class III designation.

Periphyton Community Composition

Algal Community Stricture % Composition % Bacillariophyta 76.00 % Chlorophycota 0.33 % Cryptophycophyta 0 % Cyanophycota 23.67

Number of Taxa 57

Of the 57 algal taxa observed, the majority of the periph yton community was composed of diatoms. Algal growth was very sparse throughout the stream, and no nuisance algal growth was found.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communities) at East Fork Manatee River. Based on our analyses, the Department concluded that the site was influenced only by low levels of anthropogenic stressors and that it clearly maintained healthy biological assemblages. T hus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-5 BONE VALLEY NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Manatee River @ SR 64

STORET Station 24010002

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.46, suggesting benign human influences in the wa tershed. During the site visit, aerial photographs were examined and direct observations confirmed that the majo rity of the watershed land use was forest/natural, with some field/pasture beyond an extensive riparian buffer zone. There are no point source discharges upstream of the

site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Manatee River at SR 64 (S tation 24010002) showing wate rshed vicinity and land

use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Manatee River at SR 64 (S tation 24010002) showing close-up of sampling site.

Photograph of Manatee River at SR 64TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-6 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 109 Hydrologic Score 2

LDI Score 1.46

SCI Score 64 A Total Phosphorus Geometric Mean (mg/L) 0.560 Total Nitrogen Geometric Mean (mg/L) 0.67

The habitat assessment scored in the “Suboptimal” range, mostly due to limite d in-stream substrate diversity and availability. Despite this, the Stream Condition Index scored in the “Healthy” category, indicating a diverse assemblage of sensitive invertebrates, fully supporting the Class III designation.

Periphyton Community Composition

Algal Community Stricture % Composition % Bacillariophyta 90.00 % Chlorophycota 0 % Cryptophycophyta 0 % Cyanophycota 9.33

Number of Taxa 34

Of the 34 algal taxa observed, the majority of the periphyt on community was composed of diatoms. This site has been a DEP reference stream for 17 years, and local DEP biologists have sampled this site many times during that period. However, during the December, 17, 2008 sampling event, a significant amount of filamentous algal growth was observed. Peggy Morgan (personal communication) stated that while these typ es of blooms are common in the region during low water events, algal growth is routinely sparse at this location. There have been no additional adverse human activities or changes in watershed land use dur ing the past 17 year period, therefore it is likely that this type of algal growth is an in frequent natural condition, and that the magnitude, frequency and duration of the growth events are limited, as evidenced by the healthy invertebrate community . Ms. Morgan returned to this area of the Manatee River on March 2, 2009, and reported th at the algae observed in December was significantly reduced, and that algal coverage had re turned to typical (low coverage) le vels. This suggests that even in minimally disturbed streams with naturally elevated phosphor us levels, sporadic algal growth occurs, however the magnitude, frequency and duration of the growth events are limited.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communities) at Manatee River at SR 64. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota whic h demonstrate full support of the most sensitive designated



### use (propagation and maintenance of a healthy, we ll-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-7 NORTH CENTRAL NUTRIENT REGION

Nutrient Benchmark Site Summary



## Alapaha River @ CR 150

STORET Station 21010008

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.81, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the watershed land use was predominately forest/natur al, with some agricultural activities occurring beyond an extensive riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Alapaha River (Station 21020008) showing watershed vicinity and land use

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Alapaha River at CR 150 showing close-up of sampling site

Photograph of the Alapaha River at CR 150TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-8 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 138 Hydrologic Score 1

LDI Score 1.81

SCI Score 59 A Total Phosphorus Geometric Mean (mg/L) 0.309 Total Nitrogen Geometric Mean (mg/L) 2.07

The Habitat Assessment score was in the “Optimal” range . The SCI scored in the “Healthy” range, indicating a diverse community of aquatic invertebrates, and demonstr ating that this stream is meeting its Class III designated

use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 83.44 % Chlorophycota 2.92 % Cryptophycophyta 0 % Cyanophycota 13.31

Number of Taxa 62

Minimal to moderate periphyton growth was observed at th is site, and there were no nuisance filamentous algae. Of the 62 algal taxa observed, the majority of the pe riphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and macroinvertebrate and algal comm unities) at the Alapaha River at CR 150. Based on our analyses, the Department concluded that the site was influe nced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assembla ges. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associat ed with biota demonstrated to be fully supportive of the designated use (healthy, well balan ced populations of aquatic organisms).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-9 NORTH CENTRAL NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Suwannee River @ White Springs, FL (US 41)

STORET Station 21010040 / SUW040C1

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.27, suggesting benign human influences in the wate rshed. Before the site vi sit, aerial photographs were

examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of

the watershed land use was forest/natural with silviculture beyond an extensive forested riparian buffer zone. The majority of the water emanates from the Okeefenokee National Wildlife Refuge. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Suwannee River @ US 41 showing watershed vicinity and land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Suwannee River @ US 41 showing close-up of sampling site.

Photograph of the Suwannee River at US Hwy 41TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-10 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 145 Hydrologic Score 2

LDI Score 1.27

SCI Score 69 A Total Phosphorus Geometric Mean (mg/L) 0.154 Total Nitrogen Geometric Mean (mg/L) 1.24

The Habitat Assessment score was in the “Optimal” range . The SCI score was in the “Exceptional” category, exhibiting a diverse assemblage of sensitive aquatic inverteb rates and indicating the site is definitively meeting the Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 54.43 % Chlorophycota 8.20 % Cryptophycophyta 0 % Cyanophycota 37.38

Number of Taxa 66

Very little periphyton was observed at this site, and there was no nuisance algal growth. Of the 66 algal taxa observed, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communiti es) at the Suwannee River at US Highway 41. Based on our analyses, the Department concluded that the site w as influenced only by very lo w levels of anthropogenic stressors and that it clearly maintained healthy biol ogical assemblages. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota demonstrated to be fully supportive of the designated use (healthy, well balanced populations of aquatic organisms).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-11 NORTH CENTRAL NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Deep Creek @ US 441

STORET Station DEP010C1

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.34, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed land use was forest/nat ural with some minimal silviculture. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Deep Creek @ US 441 (Statio n DEP010C1) showing wate rshed vicinity and land

use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Deep Creek @ US 441 (Statio n DEP010C1) showing close-up of sampling site.

Photograph of Deep Creek @ US 441TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-12 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 97 Hydrologic Score 3

LDI Score 1.34

SCI Score 80 A Total Phosphorus Geometric Mean (mg/L) 0.112 Total Nitrogen Geometric Mean (mg/L) 1.04

The Habitat Assessment score was in the “Suboptimal” ra nge, predominantly due to low water velocity (drought conditions) and the presence of naturally eroding sandy banks . The SCI score was in th e “Exceptional” category, exhibiting an unusually diverse assemblage of sensitive invert ebrates and indicating the site is definitely meeting its Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 93.33 % Chlorophycota 0.33 % Cryptophycophyta 0 % Cyanophycota 6.33

Number of Taxa 58

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No nuisance algal growth was found. Of the 58 algal taxa obser ved, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communities) at Deep Creek @ US 441. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assemblages. T hus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-13 NORTH CENTRAL NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Falling Creek @ C-131

STORET Station FAL020C1

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.36, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed land use was forest/nat ural with some silviculture and field/pasture located beyond an extensive forested riparian buffer zone. Ther e are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Falling Creek @ C-131 (Station FAL020C1) showing wa tershed vicinity and

land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Falling Creek @ C-131 (Statio n FAL020C1) showing close-up of sampling site.

Photograph of Falling Creek @ C-131TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-14 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 142 Hydrologic Score 3

LDI Score 1.36

SCI Score 55 A Total Phosphorus Geometric Mean (mg/L) 0.236 Total Nitrogen Geometric Mean (mg/L) 1.22

The Habitat Assessment score was in the “Optimal” range with 142 points. The SCI score (55) was in the “Healthy” category, exhibiting a diverse assemblage of sens itive invertebrates and indicating the site is meeting its Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 98.33 % Chlorophycota 1.33 % Cryptophycophyta 0 % Cyanophycota 0.33

Number of Taxa 48

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No nuisance algal growth was found. Of the 48 algal taxa obser ved, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate commun ities) at Falling Creek @ C-131. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assemblages. T hus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-15 NORTH CENTRAL NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Little Creek @ US 441

STORET Station 21010033

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.18, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed land use was forest/natural with some silviculture. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Little Creek @ US 441 (Sta tion 21010033) showing wate rshed vicinity and land

use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Little Creek @ US 441 (Sta tion 21010033) showing clo se-up of sampling site.

Photograph of Little Creek @ US 441TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-16 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 127 Hydrologic Score 1

LDI Score 1.18

SCI Score 89 A Total Phosphorus Geometric Mean (mg/L) 0.373 Total Nitrogen Geometric Mean (mg/L) 0.72

The Habitat Assessment score was in the “Optimal” range . The SCI score was in the “Exceptional” category, indicating an exceedingly diverse assemblage of sensitive m acroinvertebrates, and demonstrating that the site is clearly meeting its designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 89.00 % Chlorophycota 0.33 % Cryptophycophyta 0 % Cyanophycota 10.67

Number of Taxa 53

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No nuisance algal growth was found. Of the 53 algal taxa obser ved, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and macroinvertebrate and algal communities) at Little Creek @ US 441. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assemblages. T hus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-17 NORTH CENTRAL NUTRIENT REGION

Nutrient Benchmark Site Summary 

## New River @ SR 18

STORET Station 21030049

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.28, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed la nd use was forest/natural with some s ilviculture and pasture located beyond a forested buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of New River @ SR 18 (Stati on 21030049) showing watershed vicinity and land

use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of New River @ SR 18 (Stati on 21030049) showing close-up of sampling site.TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-18 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 130 Hydrologic Score 2

LDI Score 1.28

SCI Score 76 Total Phosphorus Geometric Mean (mg/L) 0.229 Total Nitrogen Geometric Mean (mg/L) 1.04

The Habitat Assessment score was in the “Optimal” range . The SCI score was in the “Exceptional” category, indicating an unusually diverse community of macroinvertebrates, and demonstrating that the water body is definitively meeting its designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 75.62 % Chlorophycota 0.50 % Cryptophycophyta 0 % Cyanophycota 23.88

Number of Taxa 72

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No nuisance algal growth was found. Of the 72 algal taxa obser ved, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal communities) at New River @ SR 18. Based on our analyses, the Department concluded that the site was influenced only by very low levels of an thropogenic stressors and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota which demonstrat e full support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanc ed population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-19 NORTH CENTRAL NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Olustee Creek @ SR 100

STORET Station UNI234LV

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.32, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed land use was forest/n atural with some silviculture and pasture located well beyond a forested buffer zone. There are no po int source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Olustee Creek @ SR 100 (Station UNI234LV) showing wa tershed vicinity and

land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Olustee Creek @ SR 100 (Station UNI234LV) showing close-up of sampling

site.TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-20 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 118 Hydrologic Score 2

LDI Score 1.32

SCI Score 44 A Total Phosphorus Geometric Mean (mg/L) 0.119 Total Nitrogen Geometric Mean (mg/L) 2.05

The Habitat Assessment score was in the high end of the “Suboptimal” range, predominantly due to low water velocity. The SCI score was in the “Healthy” category, indicating a diverse community of sensitive invertebrates, and demonstrating that the water body is meeting its designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 95.77 % Chlorophycota 2.82 % Cryptophycophyta 0 % Cyanophycota 1.41

Number of Taxa 57

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No nuisance algal growth was found. Of the 57 algal taxa obser ved, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and macroinvertebrate and algal communiti es) at Olustee Creek @ SR 100. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assemblages. T hus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-21 NORTH CENTRAL NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Sampson River @ SW 106 Ave

STORET Station 3598-B

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.68, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed la nd use was forest/natural with some s ilvicultural activities and pasture beyond a forested riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Sampson River @ SW 106 Ave (Station 3598-B) showing watershed vicinity and

land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Sampson River @ SW 106 Av e (Station 3598-B) showing close-up of sampling

site.

Photograph of Sampson River @ SW 106 AveTSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-22 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 131 Hydrologic Score 4

LDI Score 1.68

SCI Score 65 A Total Phosphorus Geometric Mean (mg/L) 0.342 Total Nitrogen Geometric Mean (mg/L) 0.68

The Habitat Assessment score was in the “Optimal” range . The hydrologic score was somewhat elevated due to presence of a control structure at outlet of Lake Sampson, ho wever, local residents indicated that this structure had not been operational for at least 6 months, meaning th e contemporaneous biological community had recovered from any potential hydrologic modification. The SCI score was in the “Healthy” category, exhibiting a diverse assemblage of sensitive invertebrates and indicating the site is meeting the Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 58.33 % Chlorophycota 1.33 % Cryptophycophyta 0 % Cyanophycota 40.33

Number of Taxa 63

Minimal periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No nuisance algal growth was found. Of the 63 algal taxa obser ved, the majority of the periphyton community was composed of diatoms, with a large proportion of blue-green algae.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate commun ities) at Sampson River @ SW 106 Ave. Based on our analyses, the Department concluded that the site was influenced only by low levels of anthropogenic stressors and that it clearly maintained healthy biol ogical assemblages. Thus, not only ar e the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a healthy, we ll-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-23 NORTH CENTRAL NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Santa Fe River @ Worthington Springs

STORET Station SFR030C1

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.88, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed la nd use was forest/natural with some s ilvicultural activities and pasture beyond an extensive forested riparian buffer zone. Ther e are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Santa Fe River @ Worthi ngton Springs (Station SFR03 0C1) showing watershed vicinity and land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Santa Fe River @ Worthingt on Springs (Station SFR030C1) showing close-up of sampling site.

Photograph of Santa Fe River @ Worthington SpringsTSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-24 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 132 Hydrologic Score 2

LDI Score 1.88

SCI Score 64 A Total Phosphorus Geometric Mean (mg/L) 0.235 Total Nitrogen Geometric Mean (mg/L) 1.15

The Habitat Assessment score was in the “Optimal” ra nge. The SCI score was in the “Healthy” category, exhibiting a diverse assemblage of sensitive invertebrates and indicating the site is meeting the Class III designated

use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 61.33 % Chlorophycota 3.00 % Euglenophycota 0.33 % Cyanophycota 35.33

Number of Taxa 64

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No nuisance algal growth was found. Of the 64 algal taxa obser ved, the majority of the periphyton community was composed of diatoms, with a large proportion of blue-green algae.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communiti es) at Santa Fe River @ Worthington Springs. Based on our analyses, the Department concluded that the site w as influenced only by very lo w levels of anthropogenic stressors and that it clearly maintained healthy biol ogical assemblages. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions , they are associated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-25 NORTH CENTRAL NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Suwannee River @ CR 6

STORET Station 3535

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.22, suggesting benign human influences in the wate rshed. Before the site vi sit, aerial photographs were

examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of

the watershed land use was forest/natural with some silvic ultural activities and pasture beyond an extensive forested riparian buffer zone. The vast majority of the basin li es within the Okeefenokee National Wildlife Refuge, an area of pristine water quality conditions. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Suwannee River @CR 6 (Station 3535) showing watershed vicinity and land

use

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Suwannee River @ CR 6 (Station 3535) showing close-up of sampling site

Photograph of the Suwannee River @ CR 6TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-26 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 115 Hydrologic Score 1

LDI Score 1.22

SCI Score 52 A Total Phosphorus Geometric Mean (mg/L) 0.078 Total Nitrogen Geometric Mean (mg/L) 1.34

The Habitat Assessment score was in high end of the “Suboptimal” range. The SCI was not conducted due to a limited amount of habitat in very shallow water. Wate r levels had recently increased, and the habitat was not inundated for a sufficient period to comply with the Standard Operating Procedure. However, this site was sampled

for SCI on 10/10/2006 and 12/12/2007 and r eceived a 53 and 51, respectively, both in the “Healthy” SCI category.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 91.48 % Chlorophycota 6.89 % Cryptophycophyta 0 % Cyanophycota 1.64

Number of Taxa 45

Extensive periphyton growth was observed at this site , which is thought to be a natural phenomenon associated with the limerock substrate and very low water conditions. Of the 45 algal taxa observed, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal communities) at the Suwannee Ri ver at CR 6. Based on our analyses, the Department concluded that the site was influenced only by very low le vels of anthropogenic stressors and that the algal growth observed was a natural phenomenon. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota which suggest support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-27 NORTH CENTRAL NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Swift Creek @ CR 239

STORET Station 21030088

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.26, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed land use was forest/nat ural with silvicultural activities beyond a forested buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Swift Creek @ CR 239 (Statio n 21030088) showing watershed vicinity and land

use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Swift Creek @ CR 239 (Statio n 21030088) showing close-up of sampling site.TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-28 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 105 Hydrologic Score 2

LDI Score 1.26

SCI Score NA Total Phosphorus Geometric Mean (mg/L) 0.083 Total Nitrogen Geometric Mean (mg/L) 2.06

The Habitat Assessment score was in the “Suboptimal” range . There was no water flow at the time of sampling, therefore the SCI was not conducted, according to the SCI Standard Operating Procedure.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 99.67 % Chlorophycota 0.33 % Cryptophycophyta 0 % Cyanophycota 0

Number of Taxa 32

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No nuisance algal growth was found. Of the 32 algal taxa obser ved, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal communities) at Swift Creek @ CR 239. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stresso rs and that no adverse algal or aquatic plant issues were present. Thus, not only ar e the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota which suggest support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-29 NORTH CENTRAL NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Robinson Branch @ C-246

STORET Station ROB01C1

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.36, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed land use was forest/natural with some silvicultural activities and unimproved pasture beyond a forested riparian buffer zone. Ther e are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Robinson Branch @ C-246 (S tation ROB01C1) showing watershed vicinity and

land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Robinson Branch @ C-246 (Station ROB01C1) showing close-up of sampling

site.

Photograph of Robinson Branch @ C-246TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-30 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 128 Hydrologic Score 2

LDI Score 1.36

SCI Score 81 A Total Phosphorus Geometric Mean (mg/L) 0.158 Total Nitrogen Geometric Mean (mg/L) 0.95

The Habitat Assessment score was in the “Optimal” range . The SCI score was in the “Exceptional” category, exhibiting an unusually diverse assemblage of sensitive inve rtebrates and indicating the site is definitively meeting the Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 97.33 % Chlorophycota 0.33 % Cryptophycophyta 0 % Cyanophycota 2.33

Number of Taxa 58

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No nuisance algal growth was found. Of the 58 algal taxa obser ved, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate comm unities) at Robinson Branch @ C-246. Based on our analyses, the Department concluded that the site was influe nced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assembla ges. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are asso ciated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a health y, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-31 NORTHEAST NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Alligator Creek @ US 301 & SR115

STORET Station 19020052

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.74, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed land use was forest/n atural with some silviculture and unimproved pasture generally beyond a 100 m forested riparian zone. Ther e are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Alligator Creek @ US 301 & SR 115 (Station 1902005 2) showing watershed vicinity and land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Alligator Creek @ US 301 & SR 115 (Station 19020052) showing close-up of sampling site.

Photograph of Alligator Creek @ US 301 & SR 115TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-32 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 137 Hydrologic Score 2

LDI Score 1.74

SCI Score 63 A Total Phosphorus Geometric Mean (mg/L) 0.190 Total Nitrogen Geometric Mean (mg/L) 1.12

The Habitat Assessment score was in the “Optimal” ra nge. The SCI score was in the “Healthy” category, exhibiting a diverse assemblage of sensitive invertebrates and indicating the site is meeting the Class III designated

use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 83.02 % Chlorophycota 1.89 % Cryptophycophyta 0 % Cyanophycota 15.09

Number of Taxa 64

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No nuisance algal growth was found. Of the 64 algal taxa obser ved, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate commun ities) at Alligator Creek @ US 301 & SR 115. Based on our analyses, the Department concluded that the site w as influenced only by very lo w levels of anthropogenic stressors and that it clearly maintained healthy biol ogical assemblages. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions , they are associated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-33 NORTHEAST NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Ates Creek @ CR 315

STORET Station CLA243LV

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.18, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed land use was forest/natural with some silviculture. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Ates Creek @ CR 315 (Station CLA243LV) showing waters hed vicinity and land

use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Ates Creek @ CR 315 (Station CLA243LV) showing close-up of sampling site.

Photograph of Ates Creek @ CR 315TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-34 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 144 Hydrologic Score 2

LDI Score 1.18

SCI Score 91 A Total Phosphorus Geometric Mean (mg/L) 0.198 Total Nitrogen Geometric Mean (mg/L) 0.71

The Habitat Assessment score was in the “Optimal” range . The SCI score was in the “Exceptional” category, exhibiting an exceedingly diverse assembla ge of sensitive invertebrates and indicating the site is clearly meeting the Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 98.00 % Chlorophycota 1.00 % Cryptophycophyta 0 % Cyanophycota 0.33

Number of Taxa 41

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No nuisance algal growth was found. Of the 41 algal taxa obser ved, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communiti es) at Ates Creek @ CR 315. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assemblages. T hus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-35 NORTHEAST NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Black Creek @ SR 16

STORET Station CLA254LR

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.21, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed land use was forest/natural with some silviculture. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Black Creek @ SR 16 (Station CLA254LR) showing wate rshed vicinity and land

use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Black Creek @ SR 16 (Statio n CLA254LR) showing close-up of sampling site.

Photograph of Black Creek @ SR 16TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-36 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 133 Hydrologic Score 2

LDI Score 1.21

SCI Score 91 A Total Phosphorus Geometric Mean (mg/L) 0.116 Total Nitrogen Geometric Mean (mg/L) 0.55

The Habitat Assessment score was in the “Optimal” range . The SCI score was in the “Exceptional” category, exhibiting an unusually diverse assemblage of sensitive inve rtebrates and indicating the site is clearly meeting its Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 94.67 % Chlorophycota 1.33 % Cryptophycophyta 0 % Cyanophycota 4.00

Number of Taxa 54

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No nuisance algal growth was found. Of the 54 algal taxa obser ved, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communities) at Black Creek @ SR 16. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assemblages. T hus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-37 NORTHEAST NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Greens Creek @ CR 315

STORET Station GC315

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.33, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed land use was forest/natural with some silviculture. There are no point source discharges upstream of the site.

Image Removed Due to Copyright.

DOQQ 2004 aerial photograph of Greens Creek @ CR 315 (Station GC315) showing watershed vicinity and land

use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Greens Creek @ CR 315 (Sta tion GC315) showing close-up of sampling site.

Photograph of Greens Creek @ CR 315TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-38 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 114 Hydrologic Score 2

LDI Score 1.33

SCI Score NA Total Phosphorus Geometric Mean (mg/L) 0.020 Total Nitrogen Geometric Mean (mg/L) 0.57

The Habitat Assessment score was in the high “Suboptimal” range, mostly because of the lack of water velocity. Stream Condition Index sampling was not performed at the time of sampling due to the stagnant water conditions. An adjacent station was sampled for SCI in 2005 and 2006, and both times scored in the “Healthy” category based on SCI_2007 thresholds. This suggests that the s ite is meeting its Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 98.05 % Chlorophycota 0.65 % Cryptophycophyta 0 % Cyanophycota 1.30

Number of Taxa 42

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No nuisance algal growth was found. Of the 42 algal taxa obser ved, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal communities) at Greens Cree k @ CR 315. Based on our analyses, the Department concluded that the site was influenced only by very lo w levels of anthropogenic stressors with no algae related issues. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with plants and algae which sugg est support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanc ed population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-39 NORTHEAST NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Little St. Marys River@ CR 121 A

STORET Station 19010046

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.18, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed land use was forest/natur al with silvicultural activities beyond a forested riparian zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Little St. Marys River @ CR 121 A (Station 1901004 6) showing watershed vicinity and land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Little St. Marys River @ CR 121 A (Station 19010046) showing close-up of sampling site.

Photograph of Little St. Marys River @ CR 121 ATSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-40 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 117 Hydrologic Score 2

LDI Score 1.18

SCI Score NA Total Phosphorus Geometric Mean (mg/L) 0.048 Total Nitrogen Geometric Mean (mg/L) 1.15

The Habitat Assessment score was in the high end of th e “Suboptimal” category, predominantly sue to low water velocity. Due to the swamp-like nature of this system, SCI sampling was not appropriate and was not conducted.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 61.64 % Chlorophycota 5.90 % Euglenophycota 1.97 % Cyanophycota 29.84

Number of Taxa 75

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No nuisance algal growth was found. Of the 75 algal taxa obser ved, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal communities) at Little St. Marys River @ CR 121 A. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assemblages. T hus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-41 NORTHEAST NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Middle Prong St. Marys River @ CR 125

STORET Station 19010041

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.16, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed la nd use was forest/natural with some s ilviculture and pasture located beyond a 100 m forested buffer. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Middle Prong St. Mary s @ CR 125 (Station 19010041) showing watershed vicinity and land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Middle Prong St. Marys @ CR 125 (Station 19010041) showing close-up of sampling site.

Photograph of Middle Prong St. Marys @ CR 125TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-42 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 137 Hydrologic Score 2

LDI Score 1.16

SCI Score 78 A Total Phosphorus Geometric Mean (mg/L) 0.029 Total Nitrogen Geometric Mean (mg/L) 1.10

The Habitat Assessment score was in the “Optimal” range . Despite the naturally low dissolved oxygen measured during sampling (2.7 mg/L) the SCI score was in the “E xceptional” category, exhibiting an unusually diverse assemblage of sensitive invertebrates and indicating the site is clearly meeting its Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 81.40 % Chlorophycota 1.33 % Cryptophycophyta 0 % Cyanophycota 17.28

Number of Taxa 55

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No nuisance algal growth was found. Of the 55 algal taxa obser ved, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communiti es) at Middle Prong St. Marys @ CR 125. Based on our analyses, the Department concluded that the site was influe nced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assembla ges. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are asso ciated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a health y, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-43 NORTHEAST NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Middle Prong St. Marys River @ CR 127

STORET Station MPS

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.34, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed land use was forest/natural with some silviculture. There are no point source discharges upstream of the site.

Image Removed Due to Copyright.

DOQQ 2004 aerial photograph of Middle Prong St. Marys @ CR 127 (Station MPS) showing watershed vicinity

and land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Middle Prong St. Marys @ CR 127 (Station MPS) showing close-up of sampling

site.

Photograph of Middle Prong St. Marys @ CR 127TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-44 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 131 Hydrologic Score 2

LDI Score 1.34

SCI Score 71 A Total Phosphorus Geometric Mean (mg/L) 1.09 Total Nitrogen Geometric Mean (mg/L) 0.026

The Habitat Assessment score was in the “Optimal” range . The SCI score was in the “Exceptional” category, exhibiting an unusually diverse assemblage of sensitive invert ebrates and indicating the site is certainly meeting its Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 97.33 % Chlorophycota 0.67 % Cryptophycophyta 0 % Cyanophycota 2.00

Number of Taxa 42

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No nuisance algal growth was found. Of the 42 algal taxa obser ved, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communiti es) at Middle Prong St. Marys @ CR 127. Based on our analyses, the Department concluded that the site was influe nced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assembla ges. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are asso ciated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a health y, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-45 NORTHEAST NUTRIENT REGION

Nutrient Benchmark Site Summary 

## North Fork Black Creek @ Jennings Landing

STORET Station 14264

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.62, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed land use was forest/natural with some silv iculture and pasture located beyond an extensive forested riparian buffer zone. There ar e no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of North Fork Black Creek @ Jennings Landing (Station 14264) showing watershed vicinity and land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of North Fork Black Creek @ Jennings Landing (Station 14264) showing close-up of sampling site.

Photograph of North Fork Black Creek @ Jennings LandingTSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-46 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 137 Hydrologic Score 2

LDI Score 1.62

SCI Score 73 A Total Phosphorus Geometric Mean (mg/L) 0.038 Total Nitrogen Geometric Mean (mg/L) 0.51

The Habitat Assessment score was in the “Optimal” range . The SCI score was in the “Exceptional” category, exhibiting an unusually diverse assemblage of sensitive inve rtebrates and indicating the site is definitively meeting the Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 69.33 % Chlorophycota 1.33 % Cryptophycophyta 0 % Cyanophycota 29.33

Number of Taxa 48

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No nuisance algal growth was found. Of the 48 algal taxa obser ved, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communities) at North Fork Black Creek @ Jennings Landing. Based on our analyses, the Department concluded that th e site was influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a healthy, wellbalanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-47 NORTHEAST NUTRIENT REGION

Nutrient Benchmark Site Summary



## Peters Creek @ CR 315 A

STORET Station CLA246GS

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.21, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed la nd use was forest/natural with some s ilviculture and pasture located beyond a forested riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Peters Creek @ CR315A (Station CLA246GS) showing watershed vicinity and

land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Peters Creek @ CR315A (Station CLA246GS) showing close-up of sampling

site.

Photograph of Peters Creek @ CR315ATSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-48 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 148 Hydrologic Score 2

LDI Score 1.21

SCI Score 73 A Total Phosphorus Geometric Mean (mg/L) 0.019 Total Nitrogen Geometric Mean (mg/L) 0.40

The Habitat Assessment score was in the “Optimal” range . The SCI score was in the “Exceptional” category, exhibiting a diverse assemblage of sensitive invertebrates and indicating the site is definitively meeting the Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 94.00 % Chlorophycota 2.67 % Euglenophycota 0.67 % Cyanophycota 2.67

Number of Taxa 64

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No nuisance algal growth was found. Of the 64 algal taxa obser ved, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communities) at Peters Creek @ CR 315 A. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assemblages. T hus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-49 NORTHEAST NUTRIENT REGION

Nutrient Benchmark Site Summary 

## South Fork Black Creek @ SR 21

STORET Station 20030481

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.35, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed la nd use was forest/natural with some s ilvicultural activities beyond an extensive forested riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of South Fork Black Creek @ SR 21 (Station 20030481) showing watershed vicinity and land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of South Fork Black Creek @ SR 21 (Station 20030481) showing close-up of sampling site.

Photograph of South Fork Black Creek @ SR 21TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-50 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 144 Hydrologic Score 1

LDI Score 1.35

SCI Score 83 A Total Phosphorus Geometric Mean (mg/L) 0.093 Total Nitrogen Geometric Mean (mg/L) 0.50

The Habitat Assessment score was in the “Optimal” range . The SCI score was in the “Exceptional” category, exhibiting an exceedingly diverse assemb lage of sensitive invertebrates and indicating the site is definitively meeting its Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 72.61 % Chlorophycota 0.99 % Cryptophycophyta 0 % Cyanophycota 26.40

Number of Taxa 67

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No nuisance algal growth was found. Of the 67 algal taxa obser ved, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communities) at South Fork Black Creek @ SR 21. Based on our analyses, the Department concluded that the site was influe nced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assembla ges. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are asso ciated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a health y, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-51 NORTHEAST NUTRIENT REGION

Nutrient Benchmark Site Summary 

## St. Marys River @ SR 2

STORET Station 19010006

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.09, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed land use was forest/natural with some silvicultural activities and unimproved pasture beyond an extensive forested riparian buffer zone. There are no point source discharges upstream of the

site.

Image Removed Due to Copyright.

DOQQ 2004 aerial photograph of St. Marys at SR 2 (Station 19010006) showing watershed vicinity and land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of St. Marys at SR 2 (Stati on 19010006) showing close-up of sampling site.

Photograph of St. Marys at SR 2TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-52 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 124 Hydrologic Score 1

LDI Score 1.09

SCI Score 100 A Total Phosphorus Geometric Mean (mg/L) 0.017 Total Nitrogen Geometric Mean (mg/L) 1.27

The Habitat Assessment score was in the “Optimal” range . The SCI score was in the “Exceptional” category, indicating an exceedingly diverse community of sensitive invertebrates, and demonstrating that the site is definitively meeting its Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 93.33 % Chlorophycota 4.00 % Euglenophycota 0.33 % Cyanophycota 2.33

Number of Taxa 54

No nuisance algal growth was found. Of the 54 algal taxa observed, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communities) at St. Marys River at SR 2. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assemblages. T hus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-53 NORTHEAST NUTRIENT REGION

Nutrient Benchmark Site Summary 

## St. Marys River @ Tompkins Landing

STORET Station 19010077

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.22, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed la nd use was forest/natural with some s ilvicultural activities and pasture beyond an extensive forested riparian buffer zone. Ther e are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of St. Marys at Tompkins La nding (Station 19010077) showing watershed vicinity

and land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of St. Marys at Tompkins Landing (Station 19010077) showing close-up of sampling site.

Photograph of St. Marys at Tompkins LandingTSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-54 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 114 Hydrologic Score 2

LDI Score 1.22

SCI Score NA Total Phosphorus Geometric Mean (mg/L) 0.043 Total Nitrogen Geometric Mean (mg/L) 0.87

The Habitat Assessment score was in the high end of the “Suboptimal” range (mostly due to limited substrate availability associated with low water conditions). Since very little habitat was submerged due to the unrepresentative low water level, SCI sampling was determin ed to be inappropriate (according to the Standard Operating Procedure) and was not conducted.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 75.50 % Chlorophycota 8.94 % Cryptophycophyta 0 % Cyanophycota 15.56

Number of Taxa 73

No visual evidence of algal growth or adverse aquatic growth was observed at this site. Of the 73 algal taxa found, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal communities) at St. Marys Ri ver at Tompkins Landing. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that no adverse algal or aquatic plant issues were present. Thus , not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota which suggest support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-55 PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Aucilla River @ Highway 90

STORET Station 22040004

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.06, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed land use was forest/n atural with some field/pasture located well beyond the extensive riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Aucilla River (Station 22 040004) showing watershed vicinity and land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Aucilla River (Stati on 22040004) showing close-up of sampling site.

Photograph of the Aucilla River at Highway 90TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-56 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 126 Hydrologic Score 2

LDI Score 1.06

SCI Score 61 A Total Phosphorus Geometric Mean (mg/L) 0.090 Total Nitrogen Geometric Mean (mg/L) 3.10

The Habitat Assessment score was in the “Optimal” ra nge. The SCI score was in the “Healthy” category, exhibiting a diverse assemblage of sensitive invertebrat es and indicating the site is clearly meeting the Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 96.67 % Chlorophycota 1.33 % Cryptophycophyta 0 % Cyanophycota 2.00

Number of Taxa 30

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No nuisance algal growth was found. Of the 30 algal taxa obser ved, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communities) at the Aucilla River at Highway 90. Based on our analyses, the Department concluded that the site was influe nced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assembla ges. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associat ed with biota demonstrated to be fully supportive of the designated use (healthy, well balan ced populations of aquatic organisms).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-57 PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Blackwater River @ High way 4 NW of Baker

STORET Station 3545

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.04, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed land use was forest/natural with some silviculture. There are no point source discharges upstream of the site.

Image Removed Due to Copyright.

DOQQ 2004 aerial photograph of the Blackwater River (Sta tion 21FLGW_3545) showing wa tershed vicinity and

land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Blackwater River (S tation 21FLGW_3545) showing close-up of sampling

site.

Photograph of the Blackwater River (Station 21FLGW_3545)TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-58 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 128 Hydrologic Score 1

LDI Score 1.04

SCI Score 70 A Total Phosphorus Geometric Mean (mg/L) 0.009 Total Nitrogen Geometric Mean (mg/L) 0.40

The Habitat Assessment score was in the “Optimal” range . The SCI score was in the “Exceptional” category, exhibiting a diverse assemblage of sensitive invertebrates and indicating the site is definitively meeting the Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 88.45 % Chlorophycota 2.31 % Cryptophycophyta 0 % Cyanophycota 2.31 % Euglenophycota 0.33

Number of Taxa 39

Very little periphyton was observed at this site, and there was no nuisance algal growth. Of the 39 algal taxa observed, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communities) at the Blackwater River at Highway 4 NW of Baker. Based on our analyses, the Department concluded that th e site was influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of minimally disturbed c onditions, they are associated with biota demonstrated to be fully supportive of the designated use (healthy, well balanced populations of aquatic organisms).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-59 PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Econfina Creek @ Scott Road

STORET Station 32030023

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.57, suggesting benign human influences in the wate rshed. Before the site vi sit, aerial photographs were

examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of

the watershed land use was forest/natural with silvicul tural activities beyond the exte nsive riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Econfina Creek (Station 32030023) showing watershed vicinity and land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Econfina Creek (Station 32030023) showing close-up of sampling site.

Photograph of Econfina Creek at Scott Rd.TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-60 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 130 Hydrologic Score 1

LDI Score 1.57

SCI Score 81 A Total Phosphorus Geometric Mean (mg/L) 0.010 Total Nitrogen Geometric Mean (mg/L) 0.26

The Habitat Assessment score was in the “Optimal” range . The SCI score was in the “Exceptional” category, exhibiting a diverse assemblage of sensitive invertebrates and indicating the site is definitively meeting the Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 89.70 % Chlorophycota 5.65 % Cryptophycophyta 0 % Cyanophycota 3.65 % Euglenophycota 1.00

Number of Taxa 48

Minimal periphyton growth was observed at this s ite, which would allow for optimal substrate use by macroinvertebrates. There was no nuisance algal growth. Of the 48 algal taxa observed, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate commun ities) at Econfina Creek at Scott Road. Based on our analyses, the Department concluded that the site was influe nced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assembla ges. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associat ed with biota demonstrated to be fully supportive of the designated use (healthy, well balan ced populations of aquatic organisms).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-61 PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Econfina River @ Highway 98

STORET Station TAY170LR

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.14, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed land use was forest/natural with some silv iculture beyond an extensive riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Econfina River (Stati on TAY170LR) showing watershed vicinity and land

use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Econfina River (Stati on TAY170LR) showing close-up of sampling site.

Photograph of the Econfina River at Hwy 98TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-62 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 99 Hydrologic Score 1

LDI Score 1.14

SCI Score 41A Total Phosphorus Geometric Mean (mg/L) 0.066 Total Nitrogen Geometric Mean (mg/L) 1.21

The Habitat Assessment score was in the “Suboptimal” range due mostly to low water velocity (<0.05 m/s) and limited availability of wetted habitat, making natural drought the most influential stressor during the most recent site visit. Prior to this event, the two most recent SCI samples for this site, which were collected during normal water levels on 2/23/06 and 8/2/05, sco red 40 and 42, respectively. Both of these score were in the “Healthy” category, and the average of these scores is shown in th e table. From 1996 to 1998, a total of 18 SCIs were performed at a site located approximately 3000 m above Hi ghway 98 as part of a study to evaluate the effectiveness of forestry best management practices. All 18 of these SC Is scored in the category refe rred to as “excellent” in that version of the index, indicating that this site has a long demonstrated history of healthy biota.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 86.67 % Chlorophycota 7.0 % Cryptophycophyta 0 % Cyanophycota 6.33

Number of Taxa 36

Filamentous algal growth was observed on the shallow, rock y substrate in the first 20 m of the site, but very little periphyton was observed in the rest of the stretch. This patch of filamentous algae was likely favored by the low water conditions. Of the 36 algal taxa observed, the majority of the periphyton community was composed of

diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate commun ities) at the Econfina River at Hwy 98. Based on our analyses, the Department concluded that the site was influe nced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assembla ges. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associat ed with biota demonstrated to be fully supportive of the designated use (healthy, well balan ced populations of aquatic organisms).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-63 PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Escambia River @ Highway 4

STORET Station 3549

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.27, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed land use was forest/natur al with some silviculture and field/pasture beyond an extensive riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Escambia River (Sta tion 21FLGW_3549) showing wa tershed vicinity and

land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Escambia River (Sta tion 21FLGW_3549) showing close-up of sampling site. An extensive forested buffer is pr esent on both sides of the river.

Photograph of the Escambia River (Station 21FLGW_3549)TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-64 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 120 Hydrologic Score 2

LDI Score 1.27

SCI Score 51 A Total Phosphorus Geometric Mean (mg/L) 0.041 Total Nitrogen Geometric Mean (mg/L) 0.55

The Habitat Assessment score was in the “Optimal” range, although substrat e availability was somewhat limited due to the overall large size of the river. The SCI score was in the “Healthy” category, exhibiting a diverse assemblage of sensitive invertebrates and indicating the site is clearly meeting the Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 84.72 % Chlorophycota 5.98 % Cryptophycophyta 0 % Cyanophycota 9.30

Number of Taxa 43

Very little periphyton was observed at this site, and there was no nuisance algal growth. Of the 43 algal taxa observed, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communities) at the Escambia River at Highway 4. Based on our analyses, the Department concluded that the site was influe nced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assembla ges. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associat ed with biota demonstrated to be fully supportive of the designated use (healthy, well balan ced populations of aquatic organisms).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-65 PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Escambia River @ Highway 184

STORET Station 33020007 / 3541

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.18, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed land use was forest/natural with some silviculture and agricultural activities well beyond an extensive riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Escambia River @ 184 showing watershed vicinity and land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Escambia River @ 184 showing close-up of sampling site. An extensive forested buffer is present on both sides of the river.

Photograph of the Escambia River at Highway 184 (Station 21FLGW_3541)TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-66 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 115 Hydrologic Score 2

LDI Score 1.18

SCI Score NA Total Phosphorus Geometric Mean (mg/L) 0.035 Total Nitrogen Geometric Mean (mg/L) 0.53

The Habitat Assessment score was in the high end of th e “Suboptimal” range, predominantly due to lack of water velocity and limited substrate availab ility, related to the overall large size of the system. SCI sampling was not conducted because of the “lake-like” conditions present, a nd lack of water velocity in areas where accessible habitats were located, in accordance with the Standard Operating Procedures.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 83.72 % Chlorophycota 1.66 % Cryptophycophyta 0 % Cyanophycota 14.62

Number of Taxa 52

Minimal periphyton growth was observed at this site, which would allow for optimal substrate use by benthic invertebrate and fish communities. Of the 52 algal taxa observed, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, algal community, and local land use) at the Escambia River at Highway 184. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that no adverse algal or aquatic plant issues were present. Thus , not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota which suggest support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-67 PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Mule Creek @ SR 12

STORET Station LIB104LV

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.31, suggesting benign human influences in the wate rshed. Before the site vi sit, aerial photographs were

examined to assess the watershed land use. Direct observati ons during the site visit c onfirmed that the watershed land use was predominately forest/natural with some silv iculture. There are no point source discharges upstream of

the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Mule Creek (Station LIB104LV) showing watershed vicinity and land use

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Mule Creek (Station LIB104LV) showing close-up of sampling site

Photograph of Mule CreekTSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-68 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 132 Hydrologic Score 2

LDI Score 1.31

SCI Score 67 A Total Phosphorus Geometric Mean (mg/L) 0.033 Total Nitrogen Geometric Mean (mg/L) 0.50

The Habitat Assessment score was in the “Optimal” range. The SCI scored in the “Exceptional” category, therefore Mule Creek hosts a diverse community of sensitive aquatic macroinvertebrates.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 99.0 % Chlorophycota 0 % Cryptophycophyta 0 % Cyanophycota 1.0

Number of Taxa 22

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic invertebrate and fish communities. Of the 22 algal taxa observed, the majority of the periphyton community was composed of diatoms. No problematic filamentous algal growth was found.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communities) at Mule Creek. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assemblages. T hus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biot a demonstrated to be fully supportive of the designated use (healthy, well balanced popul ations of aquatic organisms).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-69 PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Quincy Creek above 267

STORET Station 22020093

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.34, suggesting benign human influences in the watershed. Direct observations during the site visit confirmed that the majority of the watershed land use was forest/natural with silviculture, agriculture, and field/pasture located beyond an adequate riparian buffe r zone. There are no direct point source discharges upstream

of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Quincy Creek (Station 2202 0093) showing watershed vicinity and land use

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Quincy Creek near 267 (Station 22020093) showing close-up of sampling site

Photograph of Quincy Creek upstream of 267TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-70 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 122 Hydrologic Score 3

LDI Score 1.34

SCI Score 57 A Total Phosphorus Geometric Mean (mg/L) 0.110 Total Nitrogen Geometric Mean (mg/L) 0.58

The Habitat Assessment score was in the “Optimal” range . Extensive deposits of “pipe clay” (Attapulgite) were noted throughout the stream, a natural geologic feature whic h would be expected to cont ribute total phosphorus to

the water. The Stream Condition Index scored in the “Healthy” category, indicating a diverse assemblage of macroinvertebrates, and demonstrating that the s ite is meeting its Class III designated use.

Periphyton Community Composition

Algal Community Stricture % Composition % Bacillariophyta 93.0 % Chlorophycota 2.0 % Cryptophycophyta 0 % Cyanophycota 5.0

Number of Taxa 53

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic invertebrate and fish communities. Of the 53 algal taxa observed, the majority of the periphyton community was composed of diatoms. No problematic filamentous algal growth was found.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate commun ities) at Quincy Creek, upstream of 267. Based on our analyses, the Department concluded that the site was influe nced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assembla ges. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associat ed with biota demonstrated to be fully supportive of the designated use (healthy, well balan ced populations of aquatic organisms).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-71 PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Sopchoppy River

STORET Station WAK158LR

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.13, suggesting benign human influences in the wate rshed. Before the site vi sit, aerial photographs were

examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of the watershed land use was forest/natural, with some limite d silviculture beyond an exte nsive riparian buffer zone. The watershed lies within the Apalachicola National Forest. There are no point source discharges upstream of the

site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Sopchoppy River (Stati on WAK158LR) showing wate rshed vicinity and land

use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Sopchoppy River (Station WAK158LR) showing close-up of sampling site. An extensive riparian forested buffer is present on both sides of the system.

Photograph of the Sopchoppy River (Station WAK158LR)TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-72 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 128 Hydrologic Score 1

LDI Score 1.13

SCI Score 64 A Total Phosphorus Geometric Mean (mg/L) 0.026 Total Nitrogen Geometric Mean (mg/L) 0.60

The Habitat Assessment score was in the “Optimal” ra nge. The SCI score was in the “Healthy” category, indicating that the site contains a diverse assemblage of sensitive invertebrates and is meeting its Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 73.05 % Chlorophycota 4.55 % Cryptophycophyta 0 % Cyanophycota 22.40

Number of Taxa 54

While a small amount of filamentous algae was found, the ma jority of the site had minimal periphyton growth. Of the 54 algal taxa observed, the majority of the pe riphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communities) at the Sopchoppy River. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assemblages. T hus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biot a demonstrated to be fully supportive of the designated use (healthy, well balanced popul ations of aquatic organisms).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-73 PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

## St. Marks River

STORET Station WAK168LR

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.40, suggesting benign human influences in the wate rshed. Before the site vi sit, aerial photographs were

examined to assess the watershed land use. Direct observati ons during the site visit c onfirmed that the watershed land use was predominately forest/natural with some silvic ulture beyond a forested riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Saint Marks River (S tation WAK168LR) showing watershed vicinity and

land use

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Saint Marks River (Sta tion WAK168LR) showing close-up of sampling site

Photograph of the Saint Marks RiverTSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-74 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 155 Hydrologic Score 2

LDI Score 1.40

SCI Score 45 A Total Phosphorus Geometric Mean (mg/L) 0.040 Total Nitrogen Geometric Mean (mg/L) 0.25

The Habitat Assessment score was in the “Optimal” ra nge. The SCI scored in the “Healthy” category, which indicates a diverse assemblage of aquatic invertebrates, and demonstrated that the stream is meeting its Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 91.36 % Chlorophycota 0.66 % Cryptophycophyta 1.00 % Cyanophycota 6.98

Number of Taxa 43

Nuisance algal growth was not an issue at this site, alt hough moderate periphyton growth was observed in isolated areas of the sampling reach, thought to be a natural cond ition. There was no habitat smothering (this element scored in the optimal range). Of the 43 algal taxa observed, the majority of the periphyton community was composed of

diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and aquatic in vertebrate communities) at the Saint Ma rks River. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assemblages. T hus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biot a demonstrated to be fully supportive of the designated use (healthy, well balanced popul ations of aquatic organisms).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-75 PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Swamp Creek at SR 159

STORET Station S232

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.51, suggesting benign human influences in the wa tershed. During the site visit, aerial photographs were examined and direct observations confirmed that the majo rity of the watershed land use was forest/natural, with minimal areas of silviculture and field/pasture located beyond an extensive forested riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Swamp Creek @ SR 159 (Statio n S232) showing watershed vicinity and land use

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Swamp Creek @ SR 159 (S tation S232) showing close-up of sampling site

Photograph of Swamp Creek at SR 159TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-76 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 112 Hydrologic Score 2

LDI Score 1.51

SCI Score 49 A Total Phosphorus Geometric Mean (mg/L) 0.170 Total Nitrogen Geometric Mean (mg/L) 0.75

The Habitat Assessment score was in the high end of the “Suboptimal” range. The Stream Condition Index scored in the “Healthy” category, indicating a diverse assemblage of macroinvertebrates, and demonstrating that the site is meeting its Class III designated use.

Periphyton Community Composition

Algal Community Stricture % Composition % Bacillariophyta 67.43 % Chlorophycota 5.92 % Cryptophycophyta 0 % Cyanophycota 25.99 % Euglenophycota 0.66

Number of Taxa 65

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic invertebrate and fish communities. Of the 65 algal taxa observed, the majority of the periphyton community was composed of diatoms. No problematic filamentous algal growth was found.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communiti es) at Swamp Creek at SR 159. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assemblages. T hus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biot a demonstrated to be fully supportive of the designated use (healthy, well balanced populations of aquatic organisms).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-77 PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary



## Telogia Creek @ CR 1641

STORET Station NUTREF001

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.24, suggesting benign human influences in the wate rshed. Before the site vi sit, aerial photographs were

examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of

the watershed land use was forest/natural with some silvic ulture beyond an extensive forested riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Telogia Creek (Station NUTREF001) showing watershed vicinity and land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Telogia Creek (Station NUTREF001) showing close-up of sampling site.

Photograph of Telogia Creek at CR 1641TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-78 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 131 Hydrologic Score 1

LDI Score 1.24

SCI Score 78 A Total Phosphorus Geometric Mean (mg/L) 0.067 Total Nitrogen Geometric Mean (mg/L) 0.47

The Habitat Assessment score was in the “Optimal” range . The SCI score was in the “Exceptional” category, indicating an unusually diverse assemblage of sensitive a quatic invertebrates, definitively supporting the Class III designation.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 85.0 % Chlorophycota 0.33 % Cryptophycophyta 0 % Cyanophycota 14.67

Number of Taxa 40

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No nuisance algal growth was found. Of the 40 algal taxa obser ved, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communiti es) at Telogia Creek at CR 1641. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assemblages. T hus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biot a demonstrated to be fully supportive of the designated use (healthy, well balanced popul ations of aquatic organisms).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-79 PANHANDLE NUTRIENT REGION

Nutrient Reference Site Summary 

## Wacissa River near Big Blue Spring

STORET Station 22040009

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.03, suggesting benign human influences in the wate rshed. Before the site vi sit, aerial photographs were

examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of

the watershed land use was forest/natural with silvicultu ral activities beyond and extensiv e forested riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Wacissa River (Station 22040009) showing watershed vicinity and land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Wacissa River (Stati on 22040009) showing close-up of sampling site.

Photograph of the Wacissa River near the headwaters.TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-80 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 138 Hydrologic Score 1

LDI Score 1.03

SCI Score 40 A Total Phosphorus Geometric Mean (mg/L) 0.046 Total Nitrogen Geometric Mean (mg/L) 0.29

The Habitat Assessment score was in the high end of th e “Suboptimal” range. The SCI score was in the “Healthy” category, exhibiting a diverse assemblage of sensitive inve rtebrates and indicating the site is clearly meeting the Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 85.43 % Chlorophycota 2.65 % Cryptophycophyta 0 % Cyanophycota 11.92

Number of Taxa 50

There was a minimal amount of periphyton at this s ite, with no nuisance algal growth. Of the 50 algal taxa observed, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communities) at the Wacissa River near Big Blue Spring. Based on our analyses, the Department concluded that the site w as influenced only by very lo w levels of anthropogenic stressors and that it clearly maintained healthy biol ogical assemblages. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota demonstrated to be fully supportive of the designated use (healthy, well balanced populations of aquatic organisms).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-81 PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Yellow River at Highway 2

STORET Station 3546

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.24, suggesting benign human influences in the wate rshed. Before the site vi sit, aerial photographs were

examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of

the watershed land use was forest/natural with some silvic ulture beyond an extensive forested riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Yellow River at Hwy 2 (Station 21FLGW_ 3546) showing watershed vicinity

and land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Yellow River (Station 21 FLGW_ 3546) showing close-up of sampling site. An extensive riparian forested buffer is present on both sides of the system.

Photograph of the Yellow River near Hwy 2TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-82 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 137 Hydrologic Score 1

LDI Score 1.24

SCI Score 79 A Total Phosphorus Geometric Mean (mg/L) 0.024 Total Nitrogen Geometric Mean (mg/L) 0.40

The Habitat Assessment score was in the “Optimal” range . The SCI score was in the “Exceptional” category, exhibiting a diverse assemblage of sensitive invertebrates and indicating the site is definitively meeting the Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 90.07 % Chlorophycota 1.99 % Cryptophycophyta 0 % Cyanophycota 7.95

Number of Taxa 50

Very little periphyton was observed at this site, and there was no nuisance algal growth. Of the 50 algal taxa observed, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communiti es) at the Yellow River at Highway 2. Based on our analyses, the Department concluded that the site was influe nced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assembla ges. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associat ed with biota demonstrated to be fully supportive of the designated use (healthy, well balan ced populations of aquatic organisms).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-83 PANHANDLE NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Yon Creek @ SR 12

STORET Station GAD106GS

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.26, suggesting benign human influences in the wate rshed. Before the site vi sit, aerial photographs were

examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of

the watershed land use was forest/natural with some silv iculture and field/pasture located beyond an extensive forested riparian buffer zone. There are no know n point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Yon Creek (Station GAD106G S) showing watershed vicinity and land use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Yon Creek (Station GAD106GS) showing close-up of sampling site.

Photograph of Yon Creek @ SR 12TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-84 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 137 Hydrologic Score 2

LDI Score 1.26

SCI Score 81 A Total Phosphorus Geometric Mean (mg/L) 0.083 Total Nitrogen Geometric Mean (mg/L) 0.86

The Habitat Assessment score was in the “Optimal” range . The SCI score was in the “Exceptional” category, indicating an unusually diverse community of sensitive aquatic invertebrates, and demonstrating that the stream is definitively meeting its Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 98.00 % Chlorophycota 0 % Cryptophycophyta 0 % Cyanophycota 2.00

Number of Taxa 23

Minimal periphyton growth was observed at this s ite, which would allow for optimal substrate use by macroinvertebrates. There was no nuisance algal growth. Of the 23 algal taxa observed, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communiti es) at Yon Creek @ SR 12. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assemblages. T hus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biot a demonstrated to be fully supportive of the designated use (healthy, well balanced popul ations of aquatic organisms).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-85 PENINSULA NUTRIENT REGION

Nutrient Benchmark Site Summary


## Bee Branch

STORET Station 28020299FTM

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.64, suggesting benign human influences in the wa tershed. During the site visit, aerial photographs were examined and direct observations confirmed that the majo rity of the watershed land use was forest/natural, with small areas of citrus and field/pasture observed beyond the forested buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright.

DOQQ 2004 aerial photograph of Bee Branch (Station 28020299F TM) showing watershed vicinity and land use. The headwaters drain an area dominated by pine flatwoods, prairie, and wetlands.

Image Removed Due to Copyright. DOQQ 2004 aerial l photograph of Bee Branch (Station 2802 0299FTM) showing close-up of sampling site. An extensive forested riparian zone was evident of both sides of the system.

Photographs of Bee Branch (Station 28020299FTM).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-86 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 147 Hydrologic Score 3

LDI Score 1.64

SCI Score 49 A Total Phosphorus Geometric Mean (mg/L) 0.080 Total Nitrogen Geometric Mean (mg/L) 1.13

The habitat assessment scored in the “Optimal” range. The Stream Condition Index scored in the “Healthy” category, exhibiting a diverse assemblage of sensitive inve rtebrates and indicating the site is clearly meeting the Class III designated use.

Periphyton Community Composition

Algal Community Stricture % Composition % Bacillariophyta 91.33 % Chlorophycota 2.67 % Euglenophycota 0.67 % Cyanophycota 4.67

Number of Taxa 60

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic invertebrate and fish communities. Of the 60 algal taxa observed, the majority of the periphyton community was composed of diatoms. No problematic filamentous algal growth was found.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal community) at Bee Branch. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrati ons reflective of minimally disturbed conditions, they are

associated with biota which demonstrate fu ll support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanc ed population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-87 PENINSULA NUTRIENT REGION

Nutrient Reference Site Summary 

## Blackwater Creek at State Road 44A

STORET Station ALT_BWC44 (20010455)

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.09, suggesting benign human influences in the wa tershed. During the site visit, aerial photographs were examined and direct observations confirmed that the majo rity of the watershed land use was forest/natural, with small areas of silviculture, and field/pasture observed be yond an extensive forested riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Blackwater Creek at Stat e Road 44A (Station BWC44 or 20010455) showing

watershed vicinity and land use. The system originates in Lake Norris, an undeveloped lake surrounded by

wetland.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Blackwater Creek at Stat e Road 44A (Station BWC44 or 20010455) showing close-up of sampling site. An extensive forested ripa rian zone was evident on both sides of the system.

Photographs of Blackwater Creek at State Road 44ATSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-88 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 125 Hydrologic Score 2

LDI Score 1.09

SCI Score 77 A Total Phosphorus Geometric Mean (mg/L) 0.050 Total Nitrogen Geometric Mean (mg/L) 1.60

The habitat assessment scored in the “Optimal” range, a nd the Stream Condition Index scored in the “Exceptional” category, indicating an unusually diverse assemblage of sensitive invertebrates, definitively supporting the Class III designation.

Periphyton Community Composition

Algal Community Stricture % Composition % Bacillariophyta 93.0 % Chlorophycota 0 % Cryptophycophyta 0 % Cyanophycota 7.0

Number of Taxa 45

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic invertebrate and fish communities. Of the 45 algal taxa observed, the majority of the periphyton community was composed of diatoms. No problematic filamentous algal growth was found.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of observa tions and measurements (hyd rology, habitat assessment, local land use, algal and macroinvertebrate communities) at Blackwater Creek at State Road 44A. Based on our analyses, the Department concluded that the site was influe nced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assembla ges. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are asso ciated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a health y, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-89 PENINSULA NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Blackwater Creek upstream of Carter Prop Bridge

STORET Station BWCCPB / 20010536

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.31, suggesting benign human influences in the wa tershed. During the site visit, aerial photographs were examined and direct observations confirmed that the majo rity of the watershed land use was forest/natural, with small areas of silviculture, and field/pasture observed be yond an extensive forested riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Blackwater Creek upstream of Carter Prop Bridge (Station BWCCPB) showing watershed vicinity and land use. The system originates in Lake Norris, an undeveloped lake surrounding by

wetland.

Image Removed Due to Copyright.DOQQ aerial photograph of Blackwater Creek upstream of Carter Prop Bridge (Station BWCCPB) showing closeup of sampling site. An extensive forested ripari an zone was evident of both sides of the system.

Photographs of Blackwater Creek ups tream of Carter Prop BridgeTSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-90 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 130 Hydrologic Score 2

LDI Score 1.31 Total Phosphorus Geometric Mean (mg/L) 0.054 Total Nitrogen Geometric Mean (mg/L) 1.28

The habitat assessment scored in the “Optimal” range. High water caused by recent rains made Stream Condition Index sampling inappropriate according to DEP standard operating procedures. Results from a Biorecon that was performed 2/7/2007 demonstrated that this site score d in the “healthy” range, indicating that the Class III designation is being fully supported.

Periphyton Community Composition

Algal Community Stricture % Composition % Bacillariophyta 72.43 % Chlorophycota 15.28 % Cryptophycophyta 0.33 % Cyanophycota 7.31 % Euglenophycota 2.99

Number of Taxa 72

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No nuisance algal growth was found. Of the 72 algal taxa obser ved, the majority of the periphyton community was composed of diatoms.

.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of observati ons and measurements (hydrology, local land use, and algal communities) at Blackwater Creek, upstream of Carter Prop Bridge. Based on our analyses, the Department concluded that the site was influenced only by very lo w levels of anthropogenic stressors and that it clearly maintained healthy biological assemblages. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota whic h demonstrate full support of the most sensitive designated



### use (propagation and maintenance of a healthy, we ll-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-91 PENINSULA NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Cow Creek @ CR 138

STORET Station 21030086

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.61, suggesting benign human influences in the watershed. Before and during the site visit, aerial photographs were examined and direct observations confirmed that the majo rity of the watershed land use was

forest/natural with some silvicultural activities and field/ pasture beyond an extensive forested riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Cow Creek @ CR 138 showing watershed vicinity and land use

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Cow Creek @ CR 138 showing close-up of sampling site

Photograph of Cow Creek near CR 138TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-92 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 134 Hydrologic Score 2

LDI Score 1.61

SCI Score NA Total Phosphorus Geometric Mean (mg/L) 0.114 Total Nitrogen Geometric Mean (mg/L) 0.39

The Habitat Assessment score was in the “Optimal” range . Stream Condition Index samp ling was not performed at this site due to the low water level and the possibilit y of recent desiccation, in accordance with the Standard Operating Procedure.

Periphyton Community Composition

Algal Community Stricture % Composition % Bacillariophyta 72.61 % Chlorophycota 1.32 % Cryptophycophyta 0 % Cyanophycota 25.74

Number of Taxa 64

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic invertebrate and fish communities. Of the 64 algal taxa observed, the majority of the periphyton community was composed of diatoms. No problematic filamentous algal growth was found.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal communities) at Cow Creek @ CR 138. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that no adverse algal or aquatic plant issues were present. Thus, not only are the nut rient concentrations reflective of minimally disturbed conditions, they are associated with biota which suggest support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-bala nced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-93 PENINSULA NUTRIENT REGION

Nutrient Benchmark Site Summary



## Cypress Branch above 78

STORET Station 28020239 / GLA630GS

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.21 suggesting benign human influences in the wate rshed. During the site visit, aerial photographs were examined and direct observations confirmed that the majo rity of the watershed land use was forest/natural, with areas of citrus and field/pasture observed beyond an extensive forested riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Cypress Branch (Station GLA630GS) showing watershed vicinity and land use. The stream originates in an area of prairie, flatwoods, and swamp.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Cypress Branch (Station GLA630GS) showing close-up of sampling site. An extensive riparian forested zone is generally present on bot h sides of the system throughout the watershed, with a

minimum of a 75-100 m buffer.

Photograph of Cypress Branch (Station GLA630GS).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-94 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 134 Hydrologic Score 2

LDI Score 1.21

SCI Score 63 A Total Phosphorus Geometric Mean (mg/L) 0.131 Total Nitrogen Geometric Mean (mg/L) 1.97

The habitat assessment scored in the “Optimal” range, and the Stream Condition Index scored in the “Healthy” category, indicating a diverse assembla ge of sensitive invertebrates, and fu lly supporting the Class III designation.

Periphyton Community Composition

Algal Community Stricture % Composition % Bacillariophyta 91.33 % Chlorophycota 0 % Cryptophycophyta 0 % Cyanophycota 8.67

Number of Taxa 48

Very little periphyton was observed at the site, which would allow optimal substrate use by macroinvertebrates. No nuisance algal growth was found. Of the 48 algal taxa obser ved, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, and local land use) at Cypress Branch. Based on our an alyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it clearly ma intained healthy biological assemblages. Thus, not only are the nutrient concentrati ons reflective of minimally disturbed conditions, they are

associated with biota which demonstrate fu ll support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanc ed population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-95 PENINSULA NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Econlockhatchee River at Snowhill Road

STORET Station ECH

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.14, suggesting benign human influences in the wa tershed. During the site visit, aerial photographs were examined and direct observations confirmed that the majo rity of the watershed land use was forest/natural, with small areas of silviculture, and field/past ure observed beyond the forested buffer zone.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Econlockhatchee River at Snowhill Road (Station ECH) showing watershed vicinity and land use. The system originates in th e Econlockhatchee River Swamp, an extensive wetland area.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Econlockhatchee River at Snowhill Road (Station ECH) showing close-up of sampling site. An extensive forested riparian zone was evident of both sides of the system.

Photographs of Econlockhatchee River at Snowhill RoadTSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-96 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 106 Hydrologic Score 2

LDI Score 1.14

SCI Score 52 A Total Phosphorus Geometric Mean (mg/L) 0.098 Total Nitrogen Geometric Mean (mg/L) 0.93

The habitat assessment score of 106 placed this site in the high “Suboptimal” range. The Stream Condition Index score of 52 was in the “Healthy” category, exhibiting a diverse assemblage of sensitive invertebrates and indicating the site is clearly meeting the Class III designated use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 90.31 % Chlorophycota 1.38 % Cryptophycophyta 0 % Cyanophycota 8.3

Number of Taxa 53

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic invertebrate and fish communities. Of the 53 algal taxa observed, the majority of the periphyton community was composed of diatoms. No problematic filamentous algal growth was found.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communiti es) at Econlockhatchee River at Snowhill Road. Based on our analyses, the Department concluded that the site w as influenced only by very lo w levels of anthropogenic stressors and that it clearly maintained healthy biol ogical assemblages. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions , they are associated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-97 PENINSULA NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Little Orange Creek

STORET Station PUT308GS

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 2.01, suggesting benign human influences in the wa tershed. During the site visit, aerial photographs were examined and direct observations confirmed that the majo rity of the watershed land use was forest/natural, with small areas of silviculture and field/pasture observed beyo nd an extensive forested riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Little Orange Creek (Stati on PUT308GS) showing wate rshed vicinity and land

use. The stream originates from Little Orange Lake, an undeveloped system surrounded by forest and swamp.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Little Orange Creek (Station PUT308GS) showing close-up of sampling site. An

extensive riparian forested buffer is generally present on bo th sides of the system throughout the watershed, with one small clear-cut area approaching within 75 m of the stream.

Photograph of Little Orange CreekTSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-98 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 131 Hydrologic Score 2

LDI Score 2.01

SCI Score 75 A Total Phosphorus Geometric Mean (mg/L) 0.201 Total Nitrogen Geometric Mean (mg/L) 1.13

The habitat assessment scored in the “Optimal” range, a nd the Stream Condition Index scored in the “Exceptional” category, indicating an unusually diverse assemblage of sensitive invertebrates, definitively supporting the Class III designated use. This is one of the few peninsular s ites where Plecopterans (stonef lies, known to be extremely sensitive to stress) are routinely found.

Periphyton Community Composition

Algal Community Stricture % Composition % Bacillariophyta 86.6 % Chlorophycota 5.7 % Cryptophycophyta 0 % Cyanophycota 7.4

Number of Taxa 48

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic invertebrate and fish communities. Of the 48 algal taxa observed, the majority of the periphyton community was composed of diatoms. No problematic filamentous algal growth was found.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communiti es) at Little Orange Creek. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assemblages. T hus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-99 PENINSULA NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Little Orange Creek below Cabbage Creek

STORET Station LOCBCC

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.54, suggesting benign human influences in the wa tershed. During the site visit, aerial photographs were examined and direct observations confirmed that the majo rity of the watershed land use was forest/natural, with small areas of silviculture, and field/pasture observed be yond an extensive forested riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Little Orange Creek below Cabbage Creek (Station LOCBCC) showing

watershed vicinity and land use. Little Orange Cr eek originates from Little Orange Lake, a completely undeveloped system surrounded by forest, and associated wetlands.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Little Orange Creek below Cabbage Creek (Station LOCBCC) showing close-up of sampling site. An extensive riparian forested wetland buffer is present on both sides of the system.

Photographs of Little Orange Creek below Cabbage CreekTSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-100 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 132 Hydrologic Score 2

LDI Score 1.54

SCI Score 89 A Total Phosphorus Geometric Mean (mg/L) 0.067 Total Nitrogen Geometric Mean (mg/L) 0.70

The habitat assessment scored in the “Optimal” range, a nd the Stream Condition Index scored in the “Exceptional” category, indicating an unusually diverse assemblage of sensitive invertebrates, definitively supporting the Class III designation.

Periphyton Community Composition

Algal Community Stricture % Composition % Bacillariophyta 84.52 % Chlorophycota 5.16 % Cryptophycophyta 0 % Cyanophycota 10.32

Number of Taxa 54

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic invertebrate and fish communities. Of the 54 algal taxa observed, the majority of the periphyton community was composed of diatoms. No problematic filamentous algal growth was found.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communiti es) at Little Orange Creek below Cabbage Creek. Based on our analyses, the Department concluded that the site w as influenced only by very lo w levels of anthropogenic stressors and that it clearly maintained healthy biol ogical assemblages. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions , they are associated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-101 PENINSULA NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Moses Creek at US 1

STORET Station 27010050

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.24, suggesting benign human influences in the wa tershed. During the site visit, aerial photographs were examined and direct observations confirmed that the majo rity of the watershed land use was forest/natural, with small areas of silviculture, and field/pasture observed beyond the forested buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright.

DOQQ 2004 aerial photograph of Moses Creek at US 1 (Station 27010050) showing watershed vicinity and land

use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Moses Creek at US 1 (Station 27010050) showing close-up of sampling site. Moses Creek originates in an area of pine flatwoods and swam p. An extensive riparian forested buffer is present on both sides of the system.

Photograph of Moses Creek at US 1TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-102 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 138 Hydrologic Score 1

LDI Score 1.24

SCI Score 60 A Total Phosphorus Geometric Mean (mg/L) 0.081 Total Nitrogen Geometric Mean (mg/L) 1.03

The habitat assessment scored in the “Optimal” range. The Stream Condition Index score of 60 was in the “Healthy” category, exhibiting a diverse assemblage of sens itive invertebrates and indicating the site is meeting the Class III designated use.

Periphyton Community Composition

Algal Community Stricture % Composition % Bacillariophyta 14.33 % Chlorophycota 1.33 % Euglenophycota 1.67 % Cyanophycota 81.67

Number of Taxa 71

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic invertebrate and fish communities. Of the 71algal taxa observed, including 66 diatom taxa, the majority of the periphyton community was composed of blue-green algae. No problematic filamentous algal growth was found.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, and local land use) at Moses Creek at US 1. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it clearly ma intained healthy biological assemblages. Thus, not only are the nutrient concentrati ons reflective of minimally disturbed conditions, they are

associated with biota which demonstrate fu ll support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanc ed population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-103 PENINSULA NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Orange Creek Upstream of Highway 21

STORET Station 21202

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.7, suggesting benign human influences in the wa tershed. During the site visit, aerial photographs were examined and direct observations confirmed that the majo rity of the watershed land use was forest/natural, with small areas of silviculture and field/pasture observed be yond a forested riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Orange Creek upstream of Highway 21 (Station 21202) showing watershed vicinity and land use. The stream originates from Orange Lake, an Outstanding Florida Water.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Orange Creek upstream of HWY 21 (Station 21202) showing close-up of sampling site. An extensive riparian forested we tland buffer is present on both sides of the system.

Photograph of Orange Creek upstream of Highway 21TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-104 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 121 Hydrologic Score 3

LDI Score 1.74

SCI Score 74 A Total Phosphorus Geometric Mean (mg/L) 0.125 Total Nitrogen Geometric Mean (mg/L) 1.43

The habitat assessment scored in the “Optimal” range, a nd the Stream Condition Index scored in the “Exceptional” category, indicating an unusua lly diverse assemblage of sensitive invertebrat es. This is one of the few peninsular sites where Plecopterans (stoneflies, known to be extremely sensitive to stress) are routinely found.

Periphyton Community Composition

Algal Community Stricture % Composition % Bacillariophyta 90.38 % Chlorophycota 1.37 % Cryptophycophyta 0 % Cyanophycota 8.25

Number of Taxa 51

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic invertebrate and fish communities. Of the 51 algal taxa observed, the majority of the periphyton community was composed of diatoms. No problematic filamentous algal growth was found.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communiti es) at Orange Creek, upstream of Highway 21. Based on our analyses, the Department concluded that the site w as influenced only by very lo w levels of anthropogenic stressors and that it clearly maintained healthy biol ogical assemblages. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions , they are associated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-105 PENINSULA NUTRIENT REGION

Nutrient Benchmark Site Summary 

## St. Johns River near DeLand

STORET Station 2236000

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.68, suggesting benign human influences in the wa tershed. During the site visit, aerial photographs were examined and direct observations confirmed that the majo rity of the watershed land use was forest/natural, with small areas of silviculture, and field/past ure observed beyond the forested buffer zone.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of St. John’s River near DeLa nd (Station 2236000) showing watershed vicinity and land use. The system originates from Blue Cypress Lake, a completely undeveloped system surrounding by forest

and wetlands.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of St. John’s River near De Land (Station 2236000) showing close-up of sampling site. An extensive riparian forested wetla nd buffer is present on both sides of the system.

Photographs of St. John’s River near DeLandTSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-106 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 128 Hydrologic Score 4

LDI Score 1.68

SCI Score NA Total Phosphorus Geometric Mean (mg/L) 0.078 Total Nitrogen Geometric Mean (mg/L) 1.39

The habitat assessment scored in the “Optimal” range. This system is characterized by very low flow, therefore Stream Condition Index sampling was inappropriate accord ing to DEP standard opera ting procedures. Aquatic vegetation present was typical of sluggish, open systems and there were no nuisance plant issues.

Periphyton Community Composition

Algal Community Stricture % Composition % Bacillariophyta 88.2 % Chlorophycota 2.4 % Cryptophycophyta 0 % Cyanophycota 9.5

Number of Taxa 53

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic invertebrate and fish communities. Of the 53 algal taxa observed, the majority of the periphyton community was composed of diatoms. No problematic filamentous algal growth was found.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal communities) at the St. Johns Ri ver near Deland. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and based upon observations during the site visit, that no adverse algal or aquatic plant issues were present. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota which suggest support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-107 PENINSULA NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Steinhatchee River @ Canal Road

STORET Station 22050083 / STN020C1

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.11, suggesting benign human influences in the wate rshed. Before the site vi sit, aerial photographs were

examined to assess the watershed land use. Direct observations during the site visit confirmed that the majority of

the watershed land use was forest/natural with silviculture beyond an extensive forested riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Steinhatchee River (Sta tion 22050083) showing watershed vicinity and land

use.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Steinhatchee River (Stati on 22050083) showing close-up of sampling site.

Photograph of Steinhatchee River at Canal RoadTSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-108 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 151 Hydrologic Score 2

LDI Score 1.11

SCI Score 41 A Total Phosphorus Geometric Mean (mg/L) 0.087 Total Nitrogen Geometric Mean (mg/L) 0.94

The Habitat Assessment score was in the “Optimal” ra nge. The SCI score was in the “Healthy” category, exhibiting a diverse assemblage of sensitive invertebrates and indicating the site is meeting the Class III designated

use.

Periphyton Community Composition

Algal Community Structure % Composition % Bacillariophyta 60.13 % Chlorophycota 3.65 % Cryptophycophyta 0 % Cyanophycota 36.21

Number of Taxa 54

This site had an isolated area of Rhizoclonium sp. mats, where the canopy was open and the water was shallow over rocky substrate. Throughout the majority of the site, only small to moderate amounts of algae were present, and this did not affect the inhabitability of the substrates by inverteb rates. Of the 54 algal taxa observed, the majority of the periphyton community was composed of diatoms.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communities) at the Steinhatchee River at Canal Rd. Based on our analyses, the Department concluded that the site was influe nced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assembla ges. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associat ed with biota demonstrated to be fully supportive of the designated use (healthy, well balan ced populations of aquatic organisms).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-109 PENINSULA NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Steven’s Branch off CR 204

STORET Station 27010070

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.29, suggesting benign human influences in the wa tershed. During the site visit, aerial photographs were examined and direct observations confirmed that the majo rity of the watershed land use was forest/natural, with small areas of silviculture, and field/pasture observed be yond an extensive forested riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Steven’s Branch off CR 204 (Station 27010070) showing watershed vicinity and land use. Steven’s Branch originates in an area of pine flatwoods, wetlands and prairie.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Steven’s Branch off CR 204 (Station 27010070) showing close-up of sampling site. An extensive riparian forested bu ffer is present on both sides of the system.

Photographs of Steven’s Branch off CR 204 (Station 27010070)TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-110 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 128 Hydrologic Score 3

LDI Score 1.29

SCI Score 76 A Total Phosphorus Geometric Mean (mg/L) 0.120 Total Nitrogen Geometric Mean (mg/L) 1.09

The habitat assessment scored in the “Optimal” range, a nd the Stream Condition Index scored in the “Exceptional” category, indicating an unusually diverse assemblage of sensitive invertebrates, definitively supporting the Class III designation.

Periphyton Community Composition

Algal Community Stricture % Composition % Bacillariophyta 75.14 % Chlorophycota 3.39 % Cryptophycophyta 0 % Cyanophycota 21.47

Number of Taxa 66

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic invertebrate and fish communities. Of the 66 algal taxa observed, the majority of the periphyton community was composed of diatoms. No problematic filamentous algal growth was found.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate commun ities) at Steven’s Branch off CR 204. Based on our analyses, the Department concluded that the site was influe nced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assembla ges. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are asso ciated with biota which demonstrate full support of the most sensitive designated 

### use (propagation and maintenance of a health y, well-balanced population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-111 PENINSULA NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Tosohatchee Creek @ WMA

STORET Station ORA331LV

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.50, suggesting benign human influences in the wa tershed. During the site visit, aerial photographs were examined and direct observations confirmed that the majo rity of the watershed land use was forest/natural, with small areas of silviculture and field/pasture observed beyo nd an extensive forested riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Tosohatchee Creek (Stati on ORA331LV) showing watershed vicinity and land use. The stream originates in a swampy area adjacent to Tosohatchee Creek State Preserve.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Tosohatchee Creek (Station ORA331LV) showing close-up of sampling site. An extensive riparian forested wetland buffe r is present on both sides of the system.

Photograph of Tosohatchee Creek (Station ORA331LV).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-112 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 116 Hydrologic Score 1

LDI Score 1.50

SCI Score NA Total Phosphorus Geometric Mean (mg/L) 0.034 Total Nitrogen Geometric Mean (mg/L) 0.77

The habitat assessment scored in the high “Suboptimal” range, with water velocity being the lowest scoring parameter. The site was deemed inappropriate for SCI sa mpling due to the swamp-like nature of the system and lack of water flow. Vegetation present was typical of minimally disturbed swamp systems.

Periphyton Community Composition

Algal Community Stricture % Composition % Bacillariophyta 89.00 % Chlorophycota 0.33 % Euglenophycota 0.33 % Cyanophycota 10.33

Number of Taxa 56

Of the 56 algal taxa identified, the majority of the periphyton community was composed of diatoms. No problematic filamentous algae were observed.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, algal community, and local land use) at Tosohatchee Creek . Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthr opogenic stressors and that no adverse algal or aquatic plant issues were present. Thus, not only are the nutrient con centrations reflective of minimally disturbed conditions, they are associated with biota which suggest support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanc ed population of fish and wildlife).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-113 PENINSULA NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Waccasassa River above SR 24

STORET Station LEV502GS

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.23, suggesting benign human influences in the wa tershed. During the site visit, aerial photographs were examined and direct observations confirmed that the majo rity of the watershed land use was forest/natural, with small areas of silviculture, and field/pasture observed be yond the forested riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Waccasassa River (Stati on LEV502GS) showing waters hed vicinity and land use. The Wacasassa River originates in an area of hardwood swamp known as Devils Hammock.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of the Waccasassa River (Stati on LEV502GS) showing close-up of sampling site.

Although there was some encroachment from a clear cut area near the site, extensive riparian forested wetland buffer is present on both sides for the majority of the system. Note th at the forested buffer still exceeded approximately 75 m at minimum, and was generally several hundred m wide.

Photographs of the Waccasassa RiverTSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-114 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 138 Hydrologic Score 1

LDI Score 1.23

SCI Score 69 A Total Phosphorus Geometric Mean (mg/L) 0.065 Total Nitrogen Geometric Mean (mg/L) 0.63

The habitat assessment scored in the high “Optimal” ra nge, and the Stream Condition Index scored in the “Exceptional” category, indicating an unusually diverse assemblage of sensitive invertebrates, definitively supporting the Class III designation.

Periphyton Community Composition

Algal Community Stricture % Composition % Bacillariophyta 84.24 % Chlorophycota 0.32 % Cryptophycophyta 0 % Cyanophycota 15.43

Number of Taxa 46

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic invertebrate and fish communities. Of the 46 algal taxa observed, the majority of the periphyton community was composed of diatoms. Although some filamentous algal growth was found in a few small areas, it did not affect habitat suitability, as evidenced by the very good SCI score.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communiti es) at the Waccasassa River. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assemblages. T hus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biot a demonstrated to be fully supportive of the designated use (healthy, well balanced popul ations of aquatic organisms).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-115 PENINSULA NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Withlacoochee River at SR 471

STORET Station WITHLACOORVR1

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.45, suggesting benign human influences in the wa tershed. During the site visit, aerial photographs were examined and direct observations confirmed that the majo rity of the watershed land use was forest/natural, with small areas of silviculture and field/pasture observed beyo nd an extensive forested riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. Aerial photograph of Withlacoochee River at SR 471 (S tation WITHLACOORVR1) show ing watershed vicinity and land use. The Withlacoochee River originates in th e Green Swamp, an extensive wetland with considerable areas in public ownership.

Image Removed Due to Copyright. Aerial photograph of Withlacoochee River at SR 471 (S tation WITHLACOORVR1) showing close-up of sampling site. An extensive riparian forested wetla nd buffer is present on both sides of the system.

Photograph of Withlacoochee River at SR 471 (Station WITHLACOORVR1).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-116 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 119 Hydrologic Score 2

LDI Score 1.45

SCI Score 46 A Total Phosphorus Geometric Mean (mg/L) 0.080 Total Nitrogen Geometric Mean (mg/L) 1.68

The habitat assessment scored in the high “suboptimal” ra nge due to no water velocity. The Stream Condition Index was not performed during this site visit due to low wa ter levels and minimal stream velocity. However, sites both upstream (station 33449) and downstr eam (station 34401) of the sampling location and within the same WBID received “healthy” SCI designations in 2 007, (51 A and 40 A, respectively) indicating that the water quality is fully supporting the Class III designated use. These sco res were averaged fo r the above table.

Periphyton Community Composition

Algal Community Stricture % Composition % Bacillariophyta 85.95 % Chlorophycota 1.3 % Cryptophycophyta 0 % Cyanophycota 12.1 % Euglenophycota 0.7

Number of Taxa 61

Minimal periphyton growth was observed at the site, which would allow for optimal substrate use by benthic invertebrate and fish communities. Of the 61 algal taxa observed, the majority of the periphyton community was composed of diatoms. No problematic filamentous algal growth was found.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate commun ities) Withlacoochee River at SR 471. Based on our analyses, the Department concluded that the site was influe nced only by very low levels of anthropogenic stressors and that it clearly maintained healthy biological assembla ges. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associat ed with biota demonstrated to be fully supportive of the designated use (healthy, well balan ced populations of aquatic organisms).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-117 PENINSULA NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Withlacoochee River at Stokes Ferry

STORET Station 3513

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.82, suggesting benign human influences in the wa tershed. During the site visit, aerial photographs were examined and direct observations confirmed that the majo rity of the watershed land use was forest/natural, with small areas of silviculture, field/pasture, and residen tial uses observed beyond a forested riparian buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Withlacoochee River at Stok es Ferry (Station 3513) showing watershed vicinity

and land use. The Withlacoochee River originates in th e Green Swamp, a very large wetland with considerable areas in public ownership.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Withlacoochee River at Stokes Ferry (Station 3513) showing close-up of sampling site. An extensive riparian forested we tland buffer is present on both sides of the system.

Photographs of the Withlacoochee River at Stokes FerryTSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-118 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 153 Hydrologic Score 4

LDI Score 1.82

SCI Score 68 A Total Phosphorus Geometric Mean (mg/L) 0.043 Total Nitrogen Geometric Mean (mg/L) 0.86

The habitat assessment scored in the high “Optimal” ra nge, and the Stream Condition Index scored in the “Exceptional” category, indicating an unusually diverse assemblage of sensitive invertebrates, definitively supporting the Class III designated use.

Periphyton Community Composition

Algal Community Stricture % Composition % Bacillariophyta 90.24 % Chlorophycota 0.7 % Cryptophycophyta 0 % Cyanophycota 9.06

Number of Taxa 40

Moderate periphyton growth was observed at the site; how ever, substrate availability fo r benthic invertebrates was not problematic, as evidenced by the “exceptional” SCI score. Of the 40 algal taxa observed, the majority of the periphyton community was composed of diatoms. No pr oblematic filamentous algal growth was found, despite the relatively open, sunny conditions characteristic of the site.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology, local land use, and algal and macroinvertebrate communiti es) at Withlacoochee River at Stokes Ferry. Based on our analyses, the Department concluded that the site w as influenced only by very lo w levels of anthropogenic stressors and that it clearly maintained healthy biol ogical assemblages. Thus, not only are the nutrient concentrations reflective of minimally disturbed conditions, they are associated with biota demonstrated to be fully supportive of the designated use (healthy, well balanced populations of aquatic organisms).TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-119 PENINSULA NUTRIENT REGION

Nutrient Benchmark Site Summary 

## Withlacoochee River at Trails End

STORET Station FL0052000087500

Land Use

This station was considered to be a candidate reference site based on th e Landscape Development Intensity Index score of 1.34, suggesting benign human influences in the wa tershed. During the site visit, aerial photographs were examined and direct observations confirmed that the majo rity of the watershed land use was forest/natural, with small areas of silviculture, field/pasture, and residentia l uses observed beyond the forested buffer zone. There are no point source discharges upstream of the site.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Withlacoochee River at Trails End (Station FL0052000087500) showing watershed vicinity and land use. The Withlacoochee Ri ver originates in the Green Swamp, a very large wetland with considerable areas in public ownership.

Image Removed Due to Copyright. DOQQ 2004 aerial photograph of Withlacoochee River at Trails End (Station FL0052000087500) showing closeup of sampling site. An extensive riparian forested wetland buffer is present on both sides of the system.

Photographs of Withlacoochee River at Trails EndTSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B17-120 Habitat, Biological and Water Quality Data

Parameter Value

Habitat Assessment 118 Hydrologic Score 2

LDI Score 1.34

SCI Score NA Total Phosphorus Geometric Mean (mg/L) 0.059 Total Nitrogen Geometric Mean (mg/L) 1.01

The habitat assessment scored in the high “Suboptimal” ra nge. The SCI was not performed due to the morphology of the system in this area (lake-like), which when couple d with low water levels, resulted in the system having no perceptible water velocity. Typical aqua tic plants observed at the site included Taxodium distichum, Hydrocotyle

sp ., Panicum hemitomon, Myriophyllum heterophyllum, and Polygonum sp., indicating healthy conditions.

Qualitative Periphyton Sampling was not performed at this site, however minimal periph yton growth was observed, which would allow for optimal substrate use by benthic invertebrate and fish communities. No problematic filamentous algal growth was found, despite the relativ ely open, sunny conditions ch aracteristic of the site.

Overall Reference Site Conclusion:

Experienced FDEP scientists conducted a series of obser vations and measurements (habitat assessment, hydrology and local land use) at Withlacoochee River at Trails End. Based on our analyses, the Department concluded that the site was influenced only by very low levels of anthr opogenic stressors and that no adverse algal or aquatic plant issues were present. Thus, not only are the nutrient con centrations reflective of minimally disturbed conditions, they are associated with biota which suggest support of the most sensitive designated 

### use (propagation and maintenance of a healthy, well-balanc ed population of fish and wildlife).