62-304.610. Hillsborough River Basin TMDLs

(1) Sparkman Branch. The bacteriological TMDL for Sparkman Branch is a median of 6.52 x 108 colonies/day for fecal coliform, and is allocated as follows:

(a) The WLA for discharges subject to the Department’s NPDES MS4 Permitting Program is a 59.3% reduction of current fecal coliform loading; and,

(b) The LA for nonpoint sources is a 59.3% reduction of current fecal coliform loading.

(2) Hillsborough River (Segment 1443E). The bacteriological TMDL for the Hillsborough River (Segment 1443E) is 400 counts/100 mL for fecal coliform, and is allocated as follows:

(a) The Wasteload Allocation for discharges subject to the Department’s National Pollutant Discharge Elimination System Wastewater Permitting Program is 3.34 x 109 colonies/day for fecal coliform;

(b) The Wasteload Allocation for discharges subject to the Department’s National Pollutant Discharge Elimination System Municipal Stormwater Permitting Program is a 51.2% reduction of current fecal coliform loading; and

(c) The Load Allocation for nonpoint sources is a 51.2% reduction of current fecal coliform loading.

(3) Lake Hunter. The TMDL for Lake Hunter is an annual average load of 6,579 pounds/year of TN and 489 pounds/year of TP, and is allocated as follows:

(a) The WLA for discharges subject to the Department’s NPDES MS4 Permitting Program is an 80% reduction of current TN and TP loading; and

(b) The LA for nonpoint sources is an annual average load of 6,579 pounds/year of TN and 489 pounds/year of TP.

(4) Baker Creek. The bacteriological TMDL for Baker Creek is a median of 1.35 x 1011 colonies/day for fecal coliform, and is allocated as follows:

(a) The WLA for discharges subject to the Department’s NPDES Wastewater Permitting Program is 8.72 x 109 colonies/day for fecal coliform;

(b) The WLA for discharges subject to the Department’s NPDES MS4 Permitting Program is a 44.4% reduction of current fecal coliform loading; and

(c) The LA for nonpoint sources is a 44.4% reduction of current fecal coliform loading.

(5) Flint Creek. The bacteriological TMDL for Flint Creek is 400 counts/100 mL for fecal coliform, and is allocated as follows:

(a) The WLA for discharges subject to the Department’s NPDES MS4 Permitting Program is a 51.2% reduction of current fecal coliform loading; and

(b) The LA for nonpoint sources is a 51.2% reduction of current fecal coliform loading.

(6) Blackwater Creek. The bacteriological TMDL for Blackwater Creek is a median of 2.07 x 1012 colonies/day for fecal coliform during high/moist conditions, which are defined as flows ranging from 33 cfs to 1,370 cfs, and a median of 6.75 x 1010 colonies/day for fecal coliform during dry conditions, which are defined as flows ranging from 2 cfs to 14 cfs, and is allocated as follows:

(a) The WLA for discharges subject to the Department’s NPDES Wastewater Permitting Program is 8.72 x 109 colonies/day for fecal coliform.

(b) The WLAs for discharges subject to the Department’s NPDES MS4 Permitting Program are a 71.6% reduction of current fecal coliform loading during high/moist conditions, and a 58.1% reduction of fecal coliform loading during dry conditions; and

(c) The LAs for nonpoint sources are a 71.6% reduction of current fecal coliform loading during high/moist conditions, and a 58.1% reduction of fecal coliform loading during dry conditions.

(7) New River. The bacteriological TMDL for the New River is a median of 6.48 x 1010 for fecal coliform, and is allocated as follows:

(a) The WLA for discharges subject to the Department’s NPDES MS4 Permitting Program is a 35.3% reduction of current fecal coliform loading; and

(b) The LA for nonpoint sources is a 35.3% reduction of current fecal coliform loading.

(8) Mill Creek. The bacteriological TMDL for Mill Creek is 400 counts/100mL for fecal coliform, and is allocated as follows:

(a) The WLA for wastewater sources is not applicable;

(b) The WLA for discharges subject to the Department’s NPDES MS4 Permitting Program is to address anthropogenic sources in the basin such that in-stream concentrations meet the fecal coliform criteria which, based on the measured concentrations from the 2001 to 2007 period, will require a 66% reduction of sources contributing to exceedances of the criteria; and

(c) The LA for nonpoint sources is to address anthropogenic sources in the basin such that in-stream concentrations meet the fecal coliform criteria which, based on the measured concentrations from the 2001 to 2007 period, will require a 66% reduction of sources contributing to exceedances of the criteria.

(9) Trout Creek. The bacteriological TMDL for Trout Creek is 400 counts/100mL for fecal coliform, and is allocated as follows:

(a) The WLA for the Hillsborough County Pebble Creek Village WWTF (FL0039896) must meet its NPDES permit conditions;

(b) The WLA for discharges subject to the Department’s NPDES MS4 Permitting Program is to address anthropogenic sources in the basin such that in-stream concentrations meet the fecal coliform criteria which, based on the measured concentrations from the 2001 to 2007 period, will require a 53% reduction of sources contributing to exceedances of the criteria; and

(c) The LA for nonpoint sources is to address anthropogenic sources in the basin such that in-stream concentrations meet the fecal coliform criteria which, based on the measured concentrations from the 2001 to 2007 period, will require a 53% reduction of sources contributing to exceedances of the criteria.

(10) Channelized Stream. The TMDLs to address the low DO and nutrient impairments are an annual average 1.16 mg/L of TN and an annual average of 0.473 mg/L of TP and are allocated as follows:

(a) The WLA for wastewater point sources is not applicable;

(b) The WLAs for discharges subject to the Department’s NPDES MS4 Permitting Program are a 52.1% reduction in anthropogenic loadings of TN and a 60.5% reduction in anthropogenic loadings of TP for the 2000-2007 period at sources contributing to exceedances of the criteria; and

(c) The LAs for nonpoint sources are a 52.1% reduction in anthropogenic loadings of TN and a 60.5% reduction in anthropogenic loadings of TP for the 2000-2007 period at sources contributing to exceedances of the criteria.

(11) Lake Thonotosassa. The nutrient TMDL for Lake Thonotosassa is a seven-year average of annual loads of 46,962 pounds per year (lbs/year) TN and 3,137 lbs/year TP, which is intended to achieve an AGM chlorophyll a concentration of 32 µg/L not to be exceeded more than once in any consecutive 3-year period, and is allocated as follows:

(a) The WLA for wastewater point sources is not applicable;

(b) The WLA for discharges subject to the Department’s NPDES MS4 Permitting Program is a 29% reduction of TN (calculated from 55,504 lbs/year) and a 89% reduction of TP (calculated from 21,943 lbs/year), which are based on the average of annual loads from the 1999-2010 period; and

(c) The LA for nonpoint sources is a 29% reduction of TN (calculated from 55,504 lbs/year) and a 89% reduction of TP (calculated from 21,943 lbs/year), which are based on the average of annual loads from the 1999-2010 period.

(12) Flint Creek. The nutrient TMDL for Flint Creek is an AGM concentration not to be exceed more than once in any consecutive 3-year period of 1.80 mg/L TN which is intended to achieve an AGM chlorophyll a concentration of 18 µg/L not to be exceeded more than once in any consecutive 3-year period, and is allocated as follows:

(a) The WLA for wastewater point sources is not applicable;

(b) The WLA for discharges subject to the Department’s NPDES MS4 Permitting Program is a 28% reduction of TN (calculated from 2.49 mg/L), which is based on the highest AGM concentration from the 1999-2010 period; and

(c) The LA for nonpoint sources is a 28% reduction of TN (calculated from 2.49 mg/L), which is based on the highest AGM concentration from the 1999-2010 period.

(13) Lake Valrico. The nutrient TMDLs for Lake Valrico are seven-year averages of annual loads of 2,317 kg/yr of TN and 90 kg/yr of TP, which are intended to achieve the applicable AGM chlorophyll a criterion for low-color, high-alkalinity lakes, and is allocated as follows:

(a) The WLA for wastewater point sources is not applicable.

(b) The WLA for discharges subject to the Department’s NPDES MS4 Permitting Program is a 29% reduction of TN (calculated from 3,259 kg/yr) and a 78% reduction of TP (calculated from 418 kg/yr), based on the highest seven-year average load from the 2011 – 2020 period; and

(c) The LA for nonpoint sources is a 29% reduction of TN (calculated from 3,259 kg/yr) and a 78% reduction of TP (calculated from 418 kg/yr), based on the highest seven-year average load from the 2011-2020 period.

Rulemaking Authority 403.061, 403.067 FS. Law Implemented 403.061, 403.062, 403.067 FS. History–New 12-22-04, Amended 7-7-10, 6-7-13, 7-23-19, 5-9-21, 8-31-23.