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Mid-Atlantic Water Protection

Total Maximum Daily Loads (TMDL)

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EPA Proposes Total Phosphorus TMDL for the Wissahickon Creek Watershed
Notice of Availability, Solicitation of Public Comment

EPA plans to establish a TMDL for total phosphorus in the Wissahickon Creek Watershed, which covers portions of Montgomery and Philadelphia Counties in Pennsylvania.  The TMDL will establish reductions necessary to address the poor stream health caused by excessive total phosphorus from wastewater treatment plants, stormwater runoff, and other sources.  EPA welcomes input from the public and interested parties regarding the proposed TMDL.  To read the full public notice and the proposed TMDL, please click on the links below:

Wisshahickon Creek TMDL Public Notice of Extension - Issued July 1, 2015
Original Wissahickon Creek TMDL Public Notice—Issued May 20, 2015 (PDF) (1 p , 56 K)
Proposed Wissahickon Creek TMDL (PDF Portfolio) (9 documents, 14 MB)
Wissahickon Creek TMDL Models (click here)
Discharge Monitoring Reports for Major Wastewater Treatment Plants (XLSX)
Discharge Monitoring Reports for North Wales (PDF) (94 pp, 34.03 M)
Evaluation of Nutrients as a Stressor of Aquatic Life in Wissahickon Creek, PA - Corrected (PDF) (41 pp, 1.71 M)
Wissahickon Creek TMDL Public Meeting Presentations (PDF Portfolio) (3 documents, 45.4M)

Please direct questions to Ashley Toy at (215) 814-2774 or toy.ashley@epa.gov.

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What is a Total Maximum Daily Load?

A Total Maximum Daily Load (TMDL) calculates the maximum amount of a pollutant that a waterbody can receive while still meeting water quality standards.

A TMDL is the sum of all the wasteload allocations (WLAs) for point sources (i.e. sewage treatment plants, stormwater discharges, industrial discharges, etc.), load allocations (LAs) for non point sources (i.e. pollutants carried by rainfall runoff from forests, agricultural lands, abandoned mine lands, etc.), and a margin of safety (MOS) to account for uncertainty.

TMDL = Wasteload Allocation (WLA) + Load Allocation (LA) + Margin of Safety (MOS)

Section 303(d) of the Clean Water Act requires that a TMDL be developed for the pollutant(s) responsible for impairing a waterbody. Each state compiles 303(d) lists which identify the impaired waterbodies contained within their state. The states include priorities on their 303(d) lists by assigning each impaired waterbody a timeline for TMDL development.

Developing TMDLs is an important step in solving water quality problems. It identifies the sources of pollutant loadings within an impaired stream, estimates the existing loads and allocates load reductions from each source in order to attain and maintain water quality standards. This process includes an opportunity for public participation.

A TMDL provides states with an outline of the reductions necessary to meet the required water quality standards in an impaired waterbody. A TMDL is submitted to EPA for review and approval and must consider each of the elements described below:

    • The TMDLs are designed to implement applicable water quality standards.
    • The TMDLs include a total allowable load as well as individual waste load allocations and load allocations.
    • The TMDLs consider the impacts of background pollutant contributions.
    • The TMDLs consider critical environmental conditions.
    • The TMDLs consider seasonal environmental variations.
    • The TMDLs include a margin of safety.
    • The TMDLs have been subject to public participation.
    • There is reasonable assurance that the TMDLs can be met.

Click below to see TMDLs developed by EPA.

TMDLs Developed by EPA
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z
You will need Adobe Acrobat Reader to view some of the PDF files on this page. See EPA's PDF page for more information about getting and using the free Acrobat Reader.
TMDL Approval Date Type of Pollution Jurisdiction
Appoquinimink River Watershed (PDF Portfolio, 2 documents, 5.3M) December 15, 2003 Nutrients, Dissolved Oxygen DE
Bear Rocks Lake (63pg, 250K) September 30, 1999 Nutrients, Sediment WV
Brush Run (PDF Portfolio, 2 documents, 2.9M) December 9, 2003 Nutrients, Siltation PA
Buckhannon River (104pg, 640K) October 20, 1998 Metals, pH WV
Burches Run Lake (48pg, 7M) October 2, 1998 Nutrients, Sediment WV
Castleman Run Lake (64pg, 228K) September 30, 1999 Nutrients, Sediment WV
Chesapeake Bay December 30, 2010 Nutrients and Sediments DE, DC, MD, NY*, PA, VA, WV
*A portion of the Chesapeake Bay Watershed is located in New York, EPA's Region 2.
Christina River High Flow (PDF Portfolio, 4 documents, 3.0M) September 26, 2006 Nutrients, Dissolved Oxygen DE, PA, MD
Christina River High Flow (PDF Portfolio, 4 documents, 3.5M) September 7, 2006 Pathogens, Siltation DE, PA, MD
Christina River Low Flow (PDF Portfolio, 4 documents, 3.7M) August 23, 2006 Nutrients, Dissolved Oxygen DE, PA, MD
Deep Run, Beach Run and Elizabeth Run (PDF Portfolio, 3 documents, 2.1M) December 9, 2004 Siltation PA
Deep Run, Beach Run and Elizabeth Run (PDF Portfolio, 2 documents, 2.2M) December 9, 2004 Nutrients PA
Delaware River Estuary PCB Zones 2-5 (PDF, 216pg, 1.5M) December 15, 2003 PCBs DE, PA, NJ*
*A portion of the Delaware River Estuary is located in New Jersey, EPA's Region 2.
Delaware River Estuary Zone 6 PCB (61pg, 1M) December 14, 2006 PCBs DE, PA, NJ*
*A portion of the Delaware River Estuary is located in New Jersey, EPA's Region 2.
Dunloup Creek Watershed (120pg, 3.8M) September 30, 2002 Metals, pH, Fecal Coliform WV
Elk River Watershed (124pg, 2.1M) September 29, 2001 Metals, pH WV
Flat Fork Creek (31pg, 967K) September 30, 2001 PCBs WV
Glanraffan Creek (PDF Portfolio, 2 documents, 1.8M) October 9, 2003 Metals, Suspended Solids PA
Goose Creek (635pg, 12.7M) July 1, 2008 Nutrients PA
Guyandotte River Watershed (154pg, 3.1M) March 30, 2004 Fecal Coliform, Metals, pH PA
Hurricane Lake (47pg, 4.3M) September 30, 1998 Metals, Nutrients, Sediment WV
Indian Creek (PDF Portfolio (2 documents, 10.6M) July 2, 2008 Nutrients, Siltation PA
Indian Creek TMDL Reconsideration (PDF Portfolio) 6 documents, 13.3M) March 21, 2014 Nutrients, Siltation PA
Kiskiminetas-Conemaugh River Watershed (PDF Portfolio) (5 documents, 14.6M) January 29, 2010 Metals, pH, Siltation PA
Lake Wallenpaupack (180pg, 3.5M) April 4, 2005 Nutrients, Siltation, Mercury PA
Lake Wallenpaupack Addendum (9 pg, 109K) October 9, 2007 Nutrients PA
Little Kanawha River Watershed (PDF Portfolio 2 documents, 3.4M) September 30, 2000 Metals WV
Lost River (67pg, 6.7M) October 2, 1998 Fecal Coliform WV
Lower Kanawha River Watershed (PDF Portfolio, 1.1M) September 30, 2000 Dioxin WV
Monongahela River Watershed (186pg, 8.6M) September 30, 2002 Metals, pH WV
Mountwood Park Lake (42pg, 3.6M) September 30, 1998 Sediment WV
Ohio River (83pg, 533K) September 30, 2002 PCBs WV
Paint Creek Watershed (149pg, 1M) September 30, 2001 Metals, pH WV
Paxton Creek (PDF Portfolio, 3 documents, 12.4M) July 1, 2008 Nutrients, Siltation PA
Pine Creek (241pp, 10.55MB) March 8, 2013 Bacteria PA
Red Clay Creek (16pg, 160K) April 7, 2007 PCBs PA
Ridenour Lake (70pg, 296K) September 27, 1999 Metals, Nutrients, Sediment WV
Sawmill Run (129pg, 4.4M) April 4, 2007 Metals, Siltation PA
Sawmill Run (563pg, 10.8M) July 1, 2008 Nutrients PA
Schuylkill River (145pg, 3.1M) April 7, 2007 PCBs PA
Shenandoah River (100pg, 2.8M) September 29, 2001 PCBs WV
South Branch Bear Creek (111pg, 4.3M) April 8, 2007 Metals, pH PA
South Fork South Branch Potomac River (64pg, 248M) February 20, 1998 Metals, pH WV
Southampton Creek (93pg, 2.6M) July 1, 2008 Nutrients, siltation PA
Stony River Watershed (213pg, 228K) September 29, 2001 Sediment WV
Tenmile Creek (49pg, 253K) October 2, 1998 PCBs WV
Tomlinson Run Lake (64pg, 4.6M) October 3, 1998 Sediment WV
Tug Fork River Watershed (47pg, 228K) September 30, 2002 Metals, pH WV
Turkey Run Lake (66pg, 269K) September 30, 1999 Metals, Nutrients, Sediment WV
Tygart Valley River Watershed (294pg, 3.5M) March 30, 2001 Metals, pH WV
Unnamed Tributary to Monongahela River at Sharton Steel (65pg, 1.1M) September 29, 2001 Metals WV
Waltz Creek (62pg, 2.4M) August 9, 2004 Metals, Siltation PA
West Fork River Watershed (292pg, 6.5M) September 30, 2002 Metals, pH WV
Wissahickon Creek (237pg, 2.3M) October 9, 2003 Nutrients, Siltation PA

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