The District is in the midst of a major strategic planning effort to address stormwater pollution from the city’s Municipal Separate Storm Sewer System (MS4).  The result of this planning effort, the Consolidated Total Maximum Daily Load (TMDL) Implementation Plan, will result in a performance based approach for reducing stormwater runoff volume and pollution, while still providing the District flexibility to plan and judiciously allocate limited resources. This Plan will set a compliance schedule for attaining TMDL Waste Load Allocations (WLAs) assigned to the MS4, with benchmarks for annual pollutant load reductions and milestones for WLAs that require many years to reach.

This project will utilize a combination of monitoring and modeling approaches to make the best possible estimates of pollution discharged from the District’s MS4, any pollution reductions that have been achieved via programs and best management practices (BMPs) implemented in recent years, and the scale of further reductions still needed to meet Clean Water Act requirements.  From that starting point, the Consolidated TMDL Implementation Plan will establish a schedule for meeting MS4 WLAs, based on projections of future BMP implementation, development, and redevelopment.

Revised Monitoring Framework

Another major requirement of the MS4 Permit is to revise the District’s monitoring program. This effort shall create and updated monitoring framework for the District, addressing existing and future needs to make wet weather pollutant loading estimates, track progress towards TMDL WLAs, and evaluate overall health of receiving waters, including biological and physical indicators. Because one of these requirements is to track progress toward TMDL WLAs, this work is being done in parallel with the development of the Consolidated TMDL Implementation Plan.  The Revised Monitoring Program shall establish a robust system to track progress towards achieving TMDL WLAs, evaluate the health of the District receiving waters, and inform and adaptive management process, including factors to consider in selecting an appropriate level of assessment.



The District Department of Environment has convened a group of stakeholders consisting of non-profits, District and federal agencies to review progress and provide feedback throughout the development of the Consolidated TMDL Implementation Plan and Revised Monitoring Framework. During periodic stakeholder meetings, information is shared and input obtained on the progress of the plan. The stakeholder group consists of representatives from the following groups:

  • District Department of Transportation
  • DC Water
  • US Environmental Protection Agency – Headquarters
  • US Environmental Protection Agency – Region 3
  • Interstate Commission on the Potomac River Basin
  • Anacostia Riverkeeper
  • Center for Watershed Protection
  • DC Building Industry Association
  • Potomac Riverkeeper
  • Natural Resources Defense Council

Anyone interested can contact the project team via this website.  In addition, drafts of the Consolidated TMDL Implementation Plan and Revised Monitoring Framework will be published for formal public comment periods upon their completion.