Fla. Admin. Code Ann. R. 62-304.640 - Withlacoochee River Basin TMDLs

(1) Rainbow Springs Group and Rainbow Springs Group Run. The nitrate-nitrite TMDL is an in-stream monthly mean concentration of 0.35 mg/L 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 nitrate-nitrite concentrations meet the TMDL target, which, based on the mean concentrations from the 2000-2010 period, will require a 82% reduction of nitrate-nitrite; and

(c) The LAs for nonpoint sources are to address anthropogenic sources in the basin such that in-stream nitrate-nitrite concentrations meet the TMDL target, which, based on the mean concentrations from the 2000-2011 period, will require a 82% reduction of nitrate-nitrite.

(2) Lake Juliana. The nutrient TMDL for Lake Juliana is an AGM of 1.03 mg/L TN, which is 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 40% reduction of TN based on mean concentrations from the 2003-2013 period; and

(c) The LA for nonpoint sources is a 40% reduction of TN based on mean concentrations from the 2003-2013 period.

(3) Gum Springs (Alligator Springs). The nutrient TMDL for Gum Springs (Alligator Springs) is an AGM of 0.35 mg/L nitrate-nitrite at the spring vent, 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 a 78% reduction of nitrate-nitrite (calculated from 1.58 mg/L), which is based on the highest AGM concentration from the 2009 - 2017 period; and

(c) The LA for nonpoint sources is 78% reduction of nitrate-nitrite (calculated from 1.58 mg/L), which is based on the highest AGM from the 2009 - 2017 period.

(4) Wilson Head Spring. The nutrient TMDL for Wilson Head Spring is an AGM of 0.35 mg/L nitrate-nitrite at the spring vent, 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 a 43% reduction of nitrate-nitrite (calculated from 0.61 mg/L), which is based on the highest AGM concentration from the 2009 - 2017 period; and

(c) The LA for nonpoint sources is 43% reduction of nitrate-nitrite (calculated from 0.61 mg/L), which is based on the highest AGM from the 2009 - 2017 period.

(5) Blue Spring (Citrus County). The nutrient TMDL for Blue Spring (Citrus County) is an AGM of 0.35 mg/L nitrate-nitrite at the spring vent, 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 a 61% reduction of nitrate-nitrite (calculated from 0.90 mg/L), which is based on the highest AGM concentration from the 2009 - 2017 period; and

(c) The LA for nonpoint sources is 61% reduction of nitrate-nitrite (calculated from 0.90 mg/L), which is based on the highest AGM from the 2009 - 2017 period.

(6) Lake Agnes. The nutrient TMDL for Lake Agnes is a seven-year average of annual loads of 10, 896 lbs/year TN and 618 lbs/year TP, which are intended to achieve the applicable chlorophyll a criterion for low color and low 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 41% reduction of TN (calculated from 18, 552 lbs/year) and a 69% reduction of TP (calculated from 1, 979 lbs/year) from the 2000-2016 period; and

(c) The LA for nonpoint sources is a 41% reduction of TN (calculated from 18, 552 lbs/year) and a 69% reduction of TP (calculated from 1, 979 lbs/year) based on average loads from the 2000-2016 period.

Notes

Fla. Admin. Code Ann. R. 62-304.640

Rulemaking Authority 403.061, 403.067 FS. Law Implemented 403.061, 403.062, 403.067 FS.

New 5-7-13, Amended by Florida Register Volume 42, Number 230, November 29, 2016 effective 12/11/2016, Amended by Florida Register Volume 45, Number 201, October 15, 2019 effective 10/29/2019, Amended by Florida Register Volume 46, Number 009, January 14, 2020 effective 1/30/2020, Amended by Florida Register Volume 47, Number 081, April 27, 2021 effective 5/9/2021.

New 5-7-13, Amended 12-11-16, 10-29-19, 1-30-20, 5-9-21.