TMDL Development for the Floyds Fork Watershed Louisville, KY - - PowerPoint PPT Presentation

TMDL Development for the Floyds Fork Watershed

Louisville, KY August 30, 2011

Presenters

• Paulette Akers KY Division of Water
• Chris Thomas Chief -- Pollution Control and

Implementation Branch

• Tim Wool

National TMDL Expert Water Quality Modeler, TOM

• Brian Watson

Director, 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:

MOS LA WLA TMDL

Where: WLA is the Sum of Waste Loads (Point Source + MS4) LA is the Sum of Loads (Nonpoint Source) MOS is the Margin of Safety

Stakeholder Process

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?