GWMP Consolidated TMDL Action Plan

This Consolidated Total Maximum Daily Load (TMDL) Action Plan documents how the National Park Service (NPS) intends to meet the "Special Conditions for Approved Total Maximum Daily Loads (TMDL) Other Than The Chesapeake Bay TMDL)" in Section I, Part B of the George Washington Memorial Parkway's (GWMP's) General Permit for Discharges of Stormwater from Small Municipal Separate Storm Sewer Systems (MS4s). The GWMP's most recent permit (VAR040100) was issued by the Virginia Department of Environmental Quality (DEQ) effective July 1, 2013 and will expire June 30, 2018.
The GWMP's MS4 permit requires the development and implementation of action plans for impaired streams where a TMDL has been established. The GWMP has been assigned a waste load allocation (WLA) as part of the TMDL that has been approved by the State Water Control Board. A TMDL establishes the maximum amount of a pollutant that can enter a waterbody without violating water quality standards.
TMDLs assign a wasteload allocation to the watersheds within a MS4s boundaries. . The TMDLs applicable to the GWMP are those where the GWMP MS4 area overlaps with the watershed of a specific waterbody with a TMDL regardless of whether those boundaries cross municipal jurisdictional lines. TMDLs applicable to the GWMP include:
• Sediment TMDL in Difficult Run.
• E. coli TMDL in Difficult Run.
• E. coli TMDL in Hunting Creek.
• E. coli TMDL in Tidal Four Mile Run.
• E. coli TMDL in Mine Run.1
• E. coli TMDL in Pimmit Run.
• Polychlorinated biphenyl (PCB) TMDL for the Potomac River.
• The Chesapeake Bay TMDL, which addresses total nitrogen, total phosphorus, and sediments. (The Chesapeake Bay TMDL is addressed in a separate GWMP Chesapeake Bay TMDL Action Plan).

This Consolidated TMDL Action Plan is a refinement of the GWMP's efforts to document and focus on reducing pollutants as required in the current MS4 Permit. The Consolidated TMDL Action Plan contains updated analyses that focus on potential strategies that may be implemented during the permit cycle. For all TMDLs, the expectation for the GWMP to achieve these reductions is through iterative implementation of programmatic BMPs. GWMP's programmatic BMPs applicable to the pollutants of concern are described in the following sections.

Document Content:

GWMP Consolidated TMDL Action Plan - FINAL - 04.11.17 (2).pdf   (1.5 MB, PDF file) Disclaimer: Links within the above document(s) were valid as of the date published. Note: Some of the files may be in PDF format and can be viewed using the Adobe Acrobat Reader software. You may download a free copy of from Adobe Systems.