TMDL Development for the Floyds Fork Watershed Louisville, KY August 30, 2011

Presenters Paulette AkersKY Division of Water Chris Thomas Chief -- Pollution Control and Implementation Branch Tim WoolNational TMDL Expert Water Quality Modeler, TOM Brian WatsonDirector, Water Resources Group Tetra Tech, Atlanta

Opening Remarks Background –Segments of the Floyds Fork Watershed are on Kentucky’s 303(d) list for: Nutrients (organic enrichment), Dissolved Oxygen & Pathogens –At KY’s Request EPA Started to Develop Nutrient TMDL in 2007 –EPA Receives Notice of Intent in 2011 Contract awarded to Tetra Tech for the development of watershed and water quality models to be used in a TMDL determination Period of Performance: May 2011 – November 15, 2012 Cost: $419,050

TMDL Process

Clean Water Act Section 303(d) Each State shall establish... The total maximum daily load...at a level necessary to implement the applicable water quality standards with seasonal variations and a margin of safety which takes into any lack of knowledge…………

TMDL Process Problem Statement –Floyds Fork is listed for: Nutrients and Dissolved Oxygen Definition of Endpoint –WQS Dissolved Oxygen: Daily Average 5 mg/L no Less than 4 mg/L Nutrients: In lakes and reservoirs and their tributaries, and other surface waters where eutrophication problems may exist, nitrogen, phosphorus, carbon, and contributing trace element discharges shall be limited in accordance with: – The scope of the problem; –The geography of the affected area; and –Relative contributions from existing and proposed sources. –Source Identification

TMDL Process –Point Source Dischargers –MS4 Dischargers –Non Point Sources Linkage Between Sources and Receiving Water Allocation

TMDLs Overall Allocation Formula: Where:  WLA is the Sum of Waste Loads (Point Source + MS4)  LAis the Sum of Loads (Nonpoint Source) MOSis the Margin of Safety

Stakeholder Process

Lessons Learned You are a Valuable Resource –Site Specific Knowledge –Engaged in the Process –Have Individual Concerns Regulatory Decision Making Process –Proposal –Final

Working Together EPA will use a stakeholder process in the development of the TMDL –Status of the Model Development will be presented at future meetings –Models will be made available for outside technical review –We encourage your involvement

Approach

TMDL Approach TMDL will be developed to meet the designated uses and applicable water quality standards TMDL will address –Current loading conditions –Determine reductions needed to meet TMDL Condition –Allocate to: Point Sources Point Source – MS4 Non Point Sources

Models to be Used Watershed Model – Loading Simulation Program C++ Water Quality Model – Water Quality Analysis Simulation Program (WASP) Both Models have been extensively used for TMDL Development Both Models have been peer reviewed Proven track record of linking these models together

Watershed Model -- Background Visual C++ programming has seamless integration with Microsoft Access and Excel Same algorithms as HSPF Simulates watershed hydrology and water quality dynamically Land use and rainfall based Outputs flows and concentrations for receiving water model (WASP)

Water Quality Model -- Background Water quality model Dynamic Full Eutrophication Kinetics Parameters simulated –DO –BOD –Ammonia –Nitrate-Nitrite –Organic Nitrogen –Organic Phosphorus –Ortho Phosphorus –Chlorophyll a

Modeling Approach Calibrate and Validate to current conditions (2000 – 2010) TMDL Reduction Scenarios –Determine the load reduction required to meet Water Quality Standards –Provide initial wasteload & load allocations Implementation –Modeling framework can be used to pollutant sharing and re-allocation

Data Review

Location Map

Elevation (Source: USGS National Elevation Dataset (NED), 1/3 Arc-Second)

Land Use (Source: 2006 National Land Cover Database (NLCD), Pervious)

Land Use (Source: 2006 National Land Cover Database (NLCD), Impervious)

Soils (Source: SSURGO)

Geology (Source: Kentucky Geography Network – kygeonet.ky.gov)

Karst Areas (Source: Kentucky Geography Network – kygeonet.ky.gov)

Point Sources (Source: KDOW and EPAR4)

Sampling Stations (Source: USGS, KDOW, MSD, and WBPs)

Meteorological Stations (Source: National Climatic Data Center (NCDC, USGS)

Septic Systems

Next Steps Evaluate any new data Setup the watershed model Calibrate/validate the watershed model Next stakeholder meeting –November 2011 Present watershed model calibration Present water quality endpoints

Questions?