Chesapeake Bay Total Maximum Daily Load (TMDL) Program


  • The United States Environmental Protection Agency (EPA) has put the Chesapeake Bay Watershed on a pollution diet 
  • This pollution diet is called the Chesapeake Bay Total Maximum Daily Load (TMDL) and is required by the Clean Water Act
  • These regulations are being enacted because voluntary programs didn’t reduce pollution in the Bay enough
  • The new federal regulations specify caps on pollutants such as nitrogen, phosphorus and sediment for Chesapeake Bay watershed states, including Virginia
  • The new pollution regulations will be implemented in three phases
  • As a part of the first phase, each state has developed a Watershed Implementation Plan (WIP) to outline a basic strategy for meeting pollution caps 
  • Phase II of implementation will be at the local level and development of the plan will begin in 2011
  • There are potential costs associated with reaching the planned pollution reduction goals as well as federal consequences for not meeting expectations

 What is NVRC doing to help local governments? 

  • NVRC has a unique understanding of Northern Virginia and is taking the lead in the local phase of the Chesapeake Bay TMDL implementation—looking out for the best interests of its member governments 
  • NVRC staff participates on EPA workgroups and implementation teams which gives the region another voice in the process of Chesapeake Bay regulation and Watershed Implementation Plan development 
  • NVRC staff gathers the information output from the larger Chesapeake Bay program and analyzes, interprets and disseminates this information to Northern Virginia's local governments 

What is a TMDL?

  • Total Maximum Daily Load
  • The maximum amount of specific pollutants allowed in a waterway
  • Numeric expression of how much of a particular pollutant that a water body can receive to achieve Water Quality Standards
  • Helpful to think of it as a “pollution diet”

What is a Watershed Implementation Plan (WIP)? 

  • State plan for pollution reduction in the Chesapeake Bay which will be periodically updated and revised
  • Proposes strategy for how pollution caps will be met as well as maximum-pollution-allowed allocations for specific waterways
  • Used by EPA in the creation of larger pollution reduction goals and strategies
  • Download Virginia’s Watershed Implementation Plan as submitted to the EPA

Why are these new regulations needed? 

  • Acceptable pollution levels or TMDLs for the Chesapeake Bay are required under the Clean Water Act
  • Voluntary programs to clean up the Chesapeake Bay haven’t reduced pollution enough
  • Pollution causes algae “blooms” which consume oxygen, creates “dead zones” where aquatic life cannot survive, and blocks sunlight, which kills aquatic plant life and species that live on the bottom of waterways
  • Goal is to restore clean water in the Chesapeake Bay and the region's streams, creeks and rivers by reducing the amount of nitrogen, phosphorus and sediment

Why are these regulations significant to Northern Virginia local governments?

  • Nothing of this scale has ever been accomplished before
  • Other watershed programs in the United States are watching us to see how we respond 
  • The practices needed to implement and achieve pollution reduction goals prescribed by the EPA are expensive 
  • EPA will be monitoring Virginia’s plan to make sure it is implemented adequately 
  • Failure to reach goals could result in changes in the way permits are approved by the EPA, the further reduction of allowable pollutants from pollution sources that are already regulated by the EPA, and could have an impact on federal grants 

 What additional resources are available?