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

Appendix B-5: Alternative Calculations for EPA’s Proposed 

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

B5-1 

Appendix B-5. Alternative Calculations for EPA’s Proposed Nutrient 

Watershed Region Distribution Approach 

Table B5-1. Summary of All Potential Nutrient Criteria Endpoints by Nutrient Watershed 

Region and Nutrient Parameter: Analysis by Site Average Water Chemistry. The 75th and 90th 

Percentile Values are in mg/L. The Mean and Standard Deviations are in Natural Logarithm 

Units. 

REGION 

BONE VALLEY PANHANDLE PENINSULA NORTH CENTRAL 

SCI=40 TN TP TN TP TN TP TN TP 

Mean 0.309 -0.752 -0.724 -3.881 -0.24 -2.879 -0.096 1.847 

Stdev 0.412 0.667 0.788 1.081 0.633 0.957 0.722 1.22 

75th 1.798 0.739 0.824 0.043 1.205 0.107 1.479 0.359 

90th 2.309 1.109 1.33 0.082 1.769 0.192 2.291 0.753 

N 22 22 128 131 82 83 17 17 

 

SCI=44 TN TP TN TP TN TP TN TP 

Mean 0.269 -0.725 -0.759 -3.904 -0.251 -2.864 0.084 1.535 

Stdev 0.444 0.7 0.787 1.111 0.651 0.986 0.539 0.987 

75th 1.765 0.777 0.796 0.043 1.207 0.111 1.564 0.419 

90th 2.31 1.188 1.283 0.084 1.792 0.202 2.17 0.763 

N 16 16 118 121 76 77 14 14 

 

SCI=50 TN TP TN TP TN TP TN TP 

Mean 0.261 -0.576 -0.838 -3.965 -0.325 -2.936 0.064 1.405 

Stdev 0.312 0.721 0.796 1.135 0.655 1.02 0.556 0.891 

75th 1.603 0.914 0.74 0.041 1.124 0.106 1.552 0.448 

90th 1.937 1.415 1.2 0.081 1.674 0.196 2.175 0.769 

N 12 12 94 97 62 63 13 13 

 

SCI=64 TN TP TN TP TN TP TN TP 

Mean 0.159 -0.999 -1.045 -4.296 -0.301 -3.129 -0.196 1.721 

Stdev 0.459 0.619 0.911 1.093 0.685 0.988 0.53 0.871 

75th 1.598 0.559 0.65 0.028 1.175 0.085 1.176 0.322 

90th 2.111 0.814 1.13 0.055 1.781 0.155 1.622 0.546 

N 4 4 43 45 31 32 8 8 

Note: Highlighted in gray are the proposed in-stream protective values (IPVs) calculated by Site Average Water 

Chemistry, Stream Condition Index (SCI) > 40, 75th percentile values. These calculations are based on station total 

nitrogen (TN) and total phosphorus (TP) average water chemistry values estimated from the updated All Sites data 

set. Multiple samples from a site were natural log transformed and geometric means were calculated. These values 

are, therefore, based on one value per site. This excludes all sites with any consecutive SCI values less than 40, 

44, 50, or 64 for multiple SCI sample sites or SCI less than 40, 44, 50, or 64 for single sample sites. It also 

excludes all sites from any waterbody ID (WBID) with a known nutrient and/or dissolved oxygen (DO) impairment 

listing. Means and standard deviations were estimated from site means and back transformed to theoretical 75th

and 90th percentiles. 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B5-2 

Table B5-2. Summary of All Potential Nutrient Criteria Endpoints by Nutrient Watershed 

Region and Nutrient Parameter: Analysis by Grab Sample Water Chemistry. The 75th and 90th 

Percentile Values are in mg/L. The Mean and Standard Deviations are in Natural Logarithm 

Units. 

REGION 

 BONE VALLEY PANHANDLE PENINSULA NORTH CENTRAL

SCI=40 TN TP TN TP TN TP TN TP 

Mean 0.236 -0.882 -0.665 -3.88 -0.235 -2.925 0.276 1.597 

Stdev 0.531 0.895 0.764 1.014 0.693 0.875 0.526 1.12 

75th 1.811 0.757 0.861 0.041 1.261 0.097 1.879 0.431 

90th 2.5 1.303 1.369 0.076 1.921 0.165 2.587 0.85 

N 57 57 338 338 273 273 32 32 

 

SCI=44 TN TP TN TP TN TP TN TP 

Mean 0.189 -0.92 -0.675 -3.899 -0.241 -2.892 0.2 1.622 

Stdev 0.551 0.917 0.776 1.049 0.727 0.899 0.5 1.193 

75th 1.752 0.74 0.859 0.041 1.283 0.102 1.711 0.441 

90th 2.447 1.291 1.376 0.078 1.995 0.176 2.318 0.911 

N 47 47 312 312 241 241 28 28 

 

SCI=50 TN TP TN TP TN TP TN TP 

Mean 0.225 -0.94 -0.759 -3.95 -0.353 -2.938 0.262 1.176 

Stdev 0.546 0.947 0.765 1.067 0.727 0.932 0.45 0.902 

75th 1.811 0.74 0.784 0.04 1.147 0.099 1.761 0.567 

90th 2.523 1.314 1.247 0.076 1.784 0.175 2.314 0.981 

N 37 37 252 252 185 185 22 22 

 

SCI=64 TN TP TN TP TN TP TN TP 

Mean -0.074 -0.998 -0.917 -4.274 -0.335 -2.738 0.166 1.399 

Stdev 0.616 0.759 0.696 0.892 0.704 0.869 0.475 0.793 

75th 1.407 0.615 0.639 0.025 1.15 0.116 1.626 0.421 

90th 2.045 0.975 0.976 0.044 1.764 0.197 2.169 0.682 

N 13 13 123 123 72 72 16 16 

Note: These calculations are based on grab TN and TP water chemistry values associated with SCI samples. This, 

therefore, includes multiple samples for some sites. It excludes all sites with any consecutive SCI values less than 

40, 44, 50, or 64 for multiple SCI sample sites or SCI less than 40, 44, 50, or 64 for single sample sites. It also 

excludes all sites from any WBID with a known nutrient and/or DO impairment listings. Means and standard 

deviations are natural logs, which were back transformed to estimate the theoretical 75th and 90th percentiles. 
TSD for U.S. EPA’s Proposed Numeric Nutrient Criteria for FL Inland Surface Fresh Waters

B5-3 

Table B5-3. Summary of All Potential Nutrient Criteria Endpoints by Nutrient Watershed 

Region and Nutrient Parameter: Analysis by Site-YR Average Water Chemistry. The 75th and 

90th Percentile Values are in mg/L. The Mean and Standard Deviations are in Natural Logarithm 

Units. 

REGION 

 BONE VALLEY PANHANDLE PENINSULA NORTH CENTRAL

SCI=40 TN TP TN TP TN TP TN TP 

Mean 0.315 -0.389 -0.693 -3.898 -0.115 -2.939 0.049 1.784 

Stdev 0.351 0.827 0.662 0.895 0.596 0.891 0.487 0.788 

75th 1.737 1.184 0.782 0.037 1.332 0.097 1.459 0.286 

90th 2.149 1.957 1.168 0.064 1.913 0.166 1.961 0.461 

N 35 35 269 273 170 167 60 61 

 

SCI=44 TN TP TN TP TN TP TN TP 

Mean 0.297 -0.284 -0.73 -3.952 -0.112 -2.923 0.075 1.687 

Stdev 0.336 0.833 0.679 0.929 0.608 0.908 0.434 0.746 

75th 1.689 1.32 0.762 0.036 1.348 0.099 1.444 0.306 

90th 2.071 2.188 1.151 0.063 1.95 0.172 1.879 0.482 

N 28 28 238 242 161 158 47 48 

 

SCI=50 TN TP TN TP TN TP TN TP 

Mean 0.294 -0.111 -0.804 -3.973 -0.183 -3.108 0.063 1.614 

Stdev 0.229 0.801 0.708 0.945 0.593 0.83 0.439 0.67 

75th 1.567 1.537 0.721 0.036 1.242 0.078 1.432 0.313 

90th 1.801 2.498 1.109 0.063 1.781 0.129 1.869 0.47 

N 23 23 180 184 124 122 45 46 

 

SCI=64 TN TP TN TP TN TP TN TP 

Mean 0.159 -0.999 -0.949 -4.124 -0.148 -3.265 -0.027 1.686 

Stdev 0.459 0.619 0.702 0.879 0.645 0.74 0.396 0.597 

75th 1.598 0.559 0.622 0.029 1.333 0.063 1.272 0.277 

90th 2.111 0.814 0.952 0.05 1.971 0.099 1.617 0.398 

N 4 4 93 96 66 66 38 39 

Note: These calculations are based on station TN and TP average water chemistry values estimated from the 

updated All Sites data set. Multiple samples from a site were natural log transformed and geometric means calculated 

for each year of data. These values are, therefore, based on multiple values for some sites. It excludes all sites with 

any consecutive SCI values less than 40, 44, 50, or 64 for multiple SCI sample sites or SCI less than 40, 44, 50, or 

64 for single sample sites. It also excludes all sites from any WBID with a known nutrient and/or DO impairment 

listings. Means and standard deviations were estimated from site means and back transformed to theoretical 75th and 

90th percentiles.