National 303(d)/TMDL Webinar Series:Revising TMDLs- Florida Perspective

Erin Rasnake

July 12, 2018

Water Quality Evaluation and TMDL Program

Water Resources

Florida has:• Population of 19,893,297 (US Census Bureau 2014)

• 98 million tourists a year (Visit Florida Website 2015)

• >1,700 rivers and streams (26,960 miles)

• 44,850 miles of canals

• 1,607,261 acres of lakes

• 2nd largest freshwater lake wholly within continental U.S. (Okeechobee) – 730 sq mi

• 1,702,390 acres of freshwater and tidal wetlands

• 2,154 coastal miles

• 1,013 known springs

• 6,573 total waterbody segments, or WBIDs

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http://dep.state.fl.us/water/docs/2016-Integrated-Report.pdf

Water Quality Restoration

• Standards

• Monitoring

• Assessment

• TMDL development*

• (NNC site-specific WQ standards)

• Basin management

action plan (BMAPs)

Implemented on a rotating basin approach

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https://floridadep.gov/dear/water-quality-evaluation-tmdl

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Total Maximum Daily Load

A TMDL is generally defined as:

The maximum amount of a pollutant that a water body

can receive and still maintain its designated uses

(e.g., drinking, fishing, swimming, shellfish harvesting)

Under Section 303(d) of the federal Clean Water

Act and the Florida Watershed Restoration Act,

TMDLs* must be developed for impaired waters.

TMDLs constitute the site-specific numeric interpretation of the narrative nutrient

criterion set forth in Paragraph 62-302.530(48)(b), F.A.C., that will replace the

otherwise applicable numeric nutrient criteria in Subsection 62-302.531(2), F.A.C.,

also known as Hierarchy 1 (H1)

Federal TMDL Program Responsibilities

The Federal Clean Water Act (1972) established requirements for states in section 303(d).

States must:

• Assess and provide lists of their impaired waters to EPA

• Develop TMDLs for impaired waters

• Identify pollutant reductions and allocations

• Develop implementation plans*

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* Although not a required element of the TMDL approval process, EPA guidance on reviewing state TMDLs recommends the development of BMPs to support implementation of the TMDL. However, EPA does not take any action on the implementation portion of the submittal.

Florida Watershed Restoration Act

The Watershed Restoration Act of 1999* established a framework for identifying impaired waters, developing TMDLs and developing and implementing restoration plans:

• Authorizes FDEP to do these things

• Authorizes Florida Department of Agriculture and Consumer Services (FDACS) to work with agriculture to implement BMPs

*(Section 403, Florida Statutes)

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Statewide Water Quality Assessments, TMDLs, and BMAPs

-as of 06/13/2018

http://fdep.maps.arcgis.com/home/webmap/viewer.html?webmap=1b4f1bf4c9c3481fb2864a415fbeca77

Process for Developing Nutrient TMDLs

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TMDL Revision Example- Lake Jesup

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History

• Lake Jesup (2981) and Lake Jesup (Near St. Johns River) (2981A)https://floridadep.gov/sites/default/files/lake-jessup-nutr_ammonia-tmdl.pdf

• TMDL adopted on 08/03/06 (effective date) 62-304.505(1) F.A.C.https://www.flrules.org/gateway/ChapterHome.asp?Chapter=62-304

• EPA Approved on 01/09/07 • EPA H1 approved on 10/27/14• BMAP adopted in May 2010https://floridadep.gov/dear/water-quality-restoration/content/basin-management-action-plans-bmaps

https://floridadep.gov/dear/water-quality-restoration/content/statewide-annual-report

• Contract established with Amec Foster Wheeler and Tetra Tech as sub-contractor in 2015 (6 task assignments)

• Public meetings: 09/09/15, 02/11/16, 06/22/16, 04/13/17, and 09/21/17

• Total Cost = $604,675.08** this also included model work for 4 new TMDLs, and 2 5-alt plans in the basin.

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• During BMAP development, the stakeholders had concerns about the model used for the TMDLs:• Lack of watershed attenuation.• Lack of in-lake water quality dynamics.

• The Florida Department of Environmental Protection (FDEP) and St. Johns River Water Management District (SJRWMD) committed to developing a new model during the first BMAP iteration.

• SJRWMD developed three models for their Lake Jesup Pollution Loading Reduction Goals (PLRG)*:• Hydrologic Simulation Program – Fortran (HSPF)• Environmental Fluid Dynamic Code (EFDC)• Water Quality Analysis Simulation Program (WASP)

Background (why revise?)

*Florida’s Water Resource Implementation Rule (62-40, Florida Administrative Code [F.A.C.]), requires water management districts to develop schedules for setting pollutant load reduction goals (PLRGs) for all surface water bodies that receive storm water. The rule also requires that water management districts assist the Florida Department of Environmental Protection (FDEP) in the development of TMDLs.

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Background, continued

• These models provided:• More detailed watershed loading.

• Updated land use coverage.

• Updated urban best management practices (BMPs) coverage.

• In-lake water quality dynamics.

• SJRWMD calibrated the models to the total loading entering Lake Jesup to determine the TP and TN targets for the PLRG.

Project Overview

• Tetra Tech and AMEC were contracted by the FDEP to evaluate and revise, as needed, SJRWMD’s models.

• The project goals are to update the models for use in:• Revising the TMDLs, as needed.

• Updating BMAP allocations for future iterations.

• The TMDLs and BMAP allocations require a different level of detail in the models than what was needed for the PLRG.

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Project Timeline

• Task 1. Evaluate the Revision and Recalibration Needs for the Existing HSPF, EFDC, and WASP Models (2015)• Draft report submitted to FDEP on August 28th.• Site visit and stakeholder meeting on September 8th and 9th.• Comments from FDEP to Tetra Tech on September 11th.

• Task 2. Revise and Recalibrate the HSPF Model• Summary report due to FDEP in mid-November 2015.• FDEP will send model and report to the stakeholders for review.

• Task 3. Model Background Simulation and Model Output Format That Meets the Needs of BMAP Load Allocation• Summary report due to FDEP in early December 2015.• FDEP will send report to the stakeholders for review.

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Project Timeline, continued

• Task 4. Revise and Recalibrate the Receiving Water Models• Summary report due to FDEP in mid-March 2016.

• FDEP will send models and report to the stakeholders for review.

• Task 5. Develop WASP Model for Three Impaired Lakes in Watershed and Assist in Developing WASP Models for Other Three Impaired Lakes• Public meeting on plan for modeling in early/mid-January 2016.• Calibrated models for three lakes due to FDEP in mid-April 2016.• FDEP will send models and reports to the stakeholders for review.

• Task 6. Prepare the Project Report• Final report on Lake Jesup due to FDEP in mid-April 2016.• Final report for three lakes due to FDEP end-June 2016.• FDEP will send model reports to the stakeholders for review.

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Six Impaired Lakes

• In addition to Lake Jesup, there are six lakes within the watershed that the FDEP has identified as impaired for nutrients.

• The HSPF model basin delineations will be updated to include the watersheds for these lakes.

• WASP models will be developed for each lake.

Waterbody Identification

Number (WBID)

Waterbody Name

2997B Howell Lake**

2994X Little Lake Howell**

2986D Lake Alma*

2997R Lake Adair*

2986E Lake Searcy*

3009 Bear Gulley Lake*

* State adopted 3/26/18** 5-alt plans

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Subwatershed Redelineations

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Water Quality Calibration and Validation Stations

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EFDC/WASP Station Location Map

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Details on Loads by Source

ParameterSurface Runoff (lbs/yr)

Ground Water Flows

(lbs/yr)

Septic Systems (lbs/yr)

Atmospheric Deposition

(lbs/yr)

Ground Water Seepage to

Lake (lbs/yr)

Sediment Flux

(lbs/yr)

TN 241,794 83,014 4,612 84,000 103,175 83,800TP 18,790 4,940 484 9,600 10,907 24,000

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Required Reductions

• TMDL in rule (62-304.505[1], F.A.C.) is a load:• 545,203 lbs/yr of TN and 41,888 lbs/yr of TP.

• To determine if these loads are being met, need to achieve in-lake concentrations (not part of rule):• 1.32 mg/L of TN and 0.094 mg/L of TP.

• TMDL estimates a 95% reduction in nitrogen fixation associated with reducing watershed loading to TMDL target:• Decrease in nutrient loading will decrease the phytoplankton

and nitrogen fixer biomass.• Decrease in TP loading into the system may make the system less

nitrogen limited.

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Required Reductions, cont.

• Ran model scenarios to confirm that these load reductions would achieve in-lake TMDL concentrations.

• Reductions are required from both anthropogenic watershed sources and in-lake sources.

• Stakeholders have provided projects to address watershed load reductions.

• SJRWMD study to evaluate potential in-lake treatment options is ongoing.• In-lake projects will be added to BMAP as feasible options are

determined.

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Allocations

• Required reductions were assigned to stakeholders based on the percentage of each stakeholder’s starting load.

• If a stakeholder is 10% of the anthropogenic starting load, then that stakeholder received 10% of the required reductions.

• This approach keeps the loading from each entity in the same proportion so each entity receives the same percent reduction requirement.

Summary

• TMDL did NOT require rule revisions

• Coordination is ongoing for WQ-27 credit for the work done on Lake Jesup

• BMAP updated with new and improved allocations

• Potential future TMDL revisions• Caloosahatchee Estuary

• Indian River Lagoon (stakeholder lead)

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Questions?

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For more information:

Contact Information:

Erin Rasnake

Program Administrator

Water Quality Evaluation and TMDL Program

Erin.Rasnake@dep.state.fl.us

(850) 245-8338

https://floridadep.gov/dear/water-quality-evaluation-tmdl

http://fdep.maps.arcgis.com/home/index.html

Acknowledgements: Marcy Frick and Brian Watson at Tetra Tech, Thank you!