62-304.300: St. Marks River Basin TMDLs
PURPOSE AND EFFECT: The purpose of the rule is to adopt new Total Maximum Daily Loads (TMDLs), and their allocations, for turbidity (addresses aquatic life impairment), total ammonia (addresses un-ionized ammonia impairment), 5-day biological oxygen demand (BOD5), total nitrogen (TN), and total phosphorus (TP) that have caused low dissolved oxygen (DO) and nutrient impairments for certain waters within the St. Marks River Basin.
SUMMARY: These new TMDLs address aquatic life, un-ionized ammonia, nutrient, and low DO impairments in the St. Marks River Basin. Specifically, the TMDL rules being proposed for adoption are for Munson Slough above Lake Munson, Lake Munson, and Munson Slough below Lake Munson. These waterbodies were verified as impaired using the methodology established in Chapter 62-303, F.A.C. The turbidity target of 31 NTU was set to meet the turbidity criterion, the total ammonia target of 0.32 mg/L was set to meet the un-ionized ammonia criterion of 0.02 mg/L, the TN and TP targets were set to meet a DO criterion of 5.0 mg/L in both Munson Slough and Lake Munson and a Trophic State Index of 56 in Lake Munson. The target concentration of turbidity (Lake Munson) was established using a percent reduction, the total ammonia target (Munson Slough below Lake Munson) was established using a regression model, the concentrations of TN and TP were established using reference stream conditions (Munson Slough above Lake Munson) and the Watershed Management model in combination with an empirical equation (Lake Munson). This rulemaking has been given OGC Case Number 09-0155.
SUMMARY OF STATEMENT OF ESTIMATED REGULATORY COSTS AND LEGISLATIVE RATIFICATION:
The Agency has determined that this will not have an adverse impact on small business or likely increase directly or indirectly regulatory costs in excess of $200,000 in the aggregate within one year after the implementation of the rule. A SERC has been prepared by the agency.
While Section 120.541, F.S., does not necessitate the preparation of a SERC in such instance, the Department has chosen to prepare a SERC for all proposed TMDLs to assist in the determination of whether any costs are incurred as a result of the TMDL, and if so, how much. The SERC analysis shows that the proposed rules are likely to increase the regulatory costs in excess of $1 million in aggregate within the five years of implementation of these rules in order to restore these impaired waters.
The Agency has determined that the proposed rule is expected to require legislative ratification based on the statement of estimated regulatory costs or if no SERC is required, the information expressly relied upon and described herein:
Any person who wishes to provide information regarding a statement of estimated regulatory costs, or provide a proposal for a lower cost regulatory alternative must do so in writing within 21 days of this notice.
RULEMAKING AUTHORITY: 403.061, 403.067 FS.
LAW IMPLEMENTED: 403.061, 403.062, 403.067 FS.
IF REQUESTED WITHIN 21 DAYS OF THE DATE OF THIS NOTICE, A HEARING WILL BE HELD AT THE DATE,TIME AND PLACE SHOWN BELOW(IF NOT REQUESTED, THIS HEARING WILL NOT BE HELD):
DATE AND TIME: Thursday, February 16, 2012, 1:30 p.m.
PLACE: Florida Department of Environmental Protection, Bob Martinez Center, 2600 Blair Stone Road, Room 609, Tallahassee, FL 32399
Pursuant to the provisions of the Americans with Disabilities Act, any person requiring special accommodations to participate in this workshop/meeting is asked to advise the agency at least 5 days before the workshop/meeting by contacting: Ms. Pat Waters at (850)245-8449. If you are hearing or speech impaired, please contact the agency using the Florida Relay Service, 1(800)955-8771 (TDD) or 1(800)955-8770 (Voice).
THE PERSON TO BE CONTACTED REGARDING THE PROPOSED RULE IS: Jan Mandrup-Poulsen, Division of Environmental Assessment and Restoration, Bureau of Watershed Restoration, Mail Station 3555, Florida Department of Environmental Protection, 2600 Blair Stone Road, Tallahassee, Florida 32399-2400, telephone (850)245-8448
THE FULL TEXT OF THE PROPOSED RULE IS:
62-304.300 St. Marks River Basin TMDLs.
(1) through (2) No change.
(3) Munson Slough Above Lake Munson. The dissolved oxygen TMDLs are 5-day biological oxygen demand (BOD5) of 2.00 mg/L, total nitrogen (TN) of 0.72 mg/L, and total phosphorus (TP) of 0.15 mg/L and are allocated as follows:
(a) The WLA for wastewater point sources is not applicable.
(b) The WLA for discharges subject to the Department’s NPDES Municipal Stormwater Permitting Program is to address anthropogenic sources in the basin such that in-stream concentrations meet the dissolved oxygen criterion and TMDL concentrations, which, based on the median concentrations from the 1973-2007 period, will require a 50 percent reduction for BOD5, an 8.35 percent reduction for TN, and a 17.53 percent reduction for TP at sources contributing to exceedances of the criterion and TMDLs.
(c) The LAs for nonpoint sources are to address anthropogenic sources in the basin such that in-stream concentrations meet the dissolved oxygen criterion and the TMDL concentrations, which, based on the median concentrations from the 1973-2007 period, will require a 50 percent reduction for BOD5, an 8.35 percent reduction for TN, and a 17.53 percent reduction for TP at sources contributing to exceedances of the criterion and TMDLs.
(d) The Margin of Safety is implicit.
(e) While the WLA and LAs for BOD5, TN, and TP have been expressed as the concentrations and percent reductions needed to attain the applicable Class III criteria, it is the combined reductions from both anthropogenic point and nonpoint sources that will result in the required reduction of in-stream BOD5, TN, and TP concentrations. However, it is not the intent of the TMDL to abate natural background conditions.
(4) Lake Munson. The turbidity TMDL is 31 Nephelometric turbidity units (NTUs) 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 Municipal Stormwater Permitting Program is to address anthropogenic sources in the basin such that in-lake concentrations meet the TMDL concentration, which, based on the median concentrations from the 1986-2007 period, will require a 31.9 percent reduction at sources contributing to exceedances.
(c) The LAs for nonpoint sources are to address anthropogenic sources in the basin such that in-lake concentrations meet the TMDL concentration, which, based on the median concentrations from the 1986-2007 period, will require a 31.9 percent reduction at sources contributing to exceedances of the TMDL.
(d) The Margin of Safety is implicit.
(e) While the WLA and LAs for turbidity have been expressed as the concentration and percent reduction needed to attain the applicable Class III criterion, it is the combined reductions from both anthropogenic point and nonpoint sources that will result in the required reduction of in-lake turbidity concentration. However, it is not the intent of the TMDL to abate natural background conditions.
(5) Lake Munson. The dissolved oxygen and nutrient [Trophic State Index (TSI)] TMDLs are in-lake concentrations for BOD5 of 2.00 mg/L, TN of 0.765 mg/L, and TP of 0.044 mg/L and are allocated as follows:
(a) The WLA for wastewater sources is not applicable.
(b) The WLA for discharges subject to the Department’s NPDES Municipal Stormwater Permitting Program is to address anthropogenic sources in the basin such that in-lake concentrations meet the dissolved oxygen criterion and the nutrient TMDL concentrations, which, based on the mean concentrations from the 2004-2008 period, will require a 50 percent reduction for BOD5, a 32.5 percent reduction for TN, and a 76.7 percent reduction for TP at sources contributing to exceedances.
(c) The LAs for nonpoint sources are to address anthropogenic sources in the basin such that in-lake concentrations meet the dissolved oxygen criterion and the TMDL concentrations, which, based on the mean concentrations from the 2004-2008 period, will require a 50 percent reduction for BOD5, a 32.5 percent reduction for TN, and a 76.7 percent reduction for TP at sources contributing to exceedances of the dissolved oxygen criterion and BOD5 and nutrients TMDL concentrations.
(d) The Margin of Safety is implicit.
(e) While the WLA and LAs for BOD5, TN and TP have been expressed as the concentrations and percent reductions needed to attain the applicable Class III criteria, it is the combined reductions from both anthropogenic point and nonpoint sources that will result in the required reduction of in-lake BOD5, TN, and TP concentrations. However, it is not the intent of the TMDL to abate natural background conditions.
(6) Munson Slough Below Lake Munson. The dissolved oxygen TMDL is an in-stream concentration for BOD5 of 2.00 mg/L 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 Municipal Stormwater Permitting Program is to address anthropogenic sources in the basin such that in-stream concentrations meet the dissolved oxygen criterion and BOD5 TMDL concentration, which, based on the mean concentration from the period 1986-2007, will require a 52.9 percent reduction for BOD5 at sources contributing to exceedances.
(c) The LAs for nonpoint sources are to address anthropogenic sources in the basin such that in-stream concentrations meet the dissolved oxygen criterion and the BOD5TMDL concentration, which, based on the mean concentrations from the 1986-2007 period, will require a 52.9 percent reduction for BOD5 at sources contributing to exceedances of the criteria.
(d) The Margin of Safety is implicit.
(e) While the WLA and LAs for BOD5 have been expressed as the concentration and percent reduction needed to attain the applicable Class III dissolved oxygen criterion, it is the combined reductions from both anthropogenic point and nonpoint sources that will result in the required reduction of in-stream BOD5 concentrations. However, it is not the intent of the TMDL to abate natural background conditions.
(7) Munson Slough Below Lake Munson. The un-ionized ammonia impairment is addressed by reductions in total ammonia. The total ammonia TMDL is an in-stream concentration of 0.32 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 Municipal Stormwater Permitting Program is to address anthropogenic sources in the basin such that in-stream un-ionized ammonia concentrations meet the water quality criterion, which, based on the mean concentration from the period 1971-2007, will require a 33.3 percent reduction of total ammonia at sources contributing to exceedances.
(c) The LAs for nonpoint sources are to address anthropogenic sources in the basin such that in-stream un-ionized ammonia concentrations meet the water quality criterion, which, based on the mean concentrations from the 1971-2007 period, will require a 33.3 percent reduction of total ammonia at sources contributing to exceedances.
(d) The Margin of Safety is implicit.
(e) While the WLA and LAs for total ammonia have been expressed as the concentration and percent reduction needed to attain the applicable Class III un-ionized ammonia criterion, it is the combined reductions from both anthropogenic point and nonpoint sources that will result in the required reduction of in-stream un-ionized ammonia concentrations. However, it is not the intent of the TMDL to abate natural background conditions.
Rulemaking Specific Authority 403.061, 403.067 FS. Law Implemented 403.061, 403.062, 403.067 FS. History–New 10-21-08, Amended_________.