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Chesapeake Bay TMDL

Ensuring Results in the Chesapeake Bay

Click on a box for more info about how EPA and the jurisdictions (Delaware, District of Columbia, Maryland, New York, Pennsylvania, Virginia and West Virginia) are ensuring that progress is made in cleaning up the Chesapeake Bay and local waters. A text version of the graphic is available below the graphic.

Adaptive management graphic showing how EPA ensures results in the Chesapeake Bay Watershed. A text version of the graphic is available further down on the page.Set TMDL allocations to meet water quality standards. The TMDL allocations are informed by the Phase I Watershed Implementation Plans.Develop and adjust two-year milestones, implement programs, and install controls.Assess and track progress and take federal actions as necessary.Use monitoring data to inform decisions and incorporate the latest science into strategies.Develop Phase III Watershed Implementation Plans


The Chesapeake Bay TMDL establishes allocations for sources and source sectors in each of the Bay jurisdictions. The TMDL allocations were set to meet applicable Bay water quality standards and were informed by the Bay jurisdictions' final Phase I Watershed Implementation Plans. Read about the TMDL allocations in the Chesapeake Bay TMDL document.

In order to ensure allocations are met, EPA and the Bay jurisdictions use cooperative federalism to adaptively manage Bay restoration that includes four elements:

  1. Bay jurisdictions develop and adjust two-year milestones, implement programs, and install controls to help ensure TMDL allocations are met. Learn more about the Bay jurisdictions' two-year milestones.
  2. EPA tracks and assesses the progress of the Bay jurisdictions in implementing their Watershed Implementation Plans and fulfilling their two-year milestones. EPA may also take federal actions as necessary. Learn more about EPA's oversight of Watershed Implementation Plans and milestones in the Chesapeake Bay Watershed.
  3. The Chesapeake Bay Program partnership, which includes EPA, uses monitoring data to inform decisions on restoration progress and incorporates the latest science into strategies to achieve watershed restoration. Learn more about progress monitoring on our Chesapeake Bay TMDL Midpoint Assessment page.
  4. Bay jurisdictions will develop Phase III Watershed Implementation Plans based on the lastest monitoring data and science. Learn more about the Bay jurisdictions' Watershed Implementation Plans.