The Chesapeake Bay Program set a goal to have pollution controls in place to achieve 75% of the 2009-2025 nitrogen, phosphorus and sediment load reductions by 2020 to achieve applicable water quality standards as established in the Chesapeake Bay Total Maximum Daily Load (Bay TMDL). As of 2020, the best management practices (BMPs) in place to reduce pollution are estimated to have achieved 47% of the nitrogen reductions, 64% of the phosphorus reductions and 100% of the sediment reductions needed to achieve the Bay TMDL’s applicable water quality standards by 2025.

According to the Chesapeake Assessment Scenario Tool (CAST), BMPs (pollution controls) put in place in the Chesapeake Bay watershed between 2009 and 2020 lowered nitrogen loads 13%, phosphorus loads 14% and sediment loads 4%. According to BMP and wastewater data from jurisdictions, and the watershed conditions incorporated in CAST, the reductions in estimated nitrogen and phosphorus pollution loads between 2009 and 2020 are mostly due to upgrades to wastewater treatment facilities. The reductions in sediment loads are primarily from the natural sector and agricultural sector. Between 2019 and 2020, nitrogen loads decreased an estimated 3.7% compared to the average annual load change of 1%, phosphorus loads decreased an estimated 3.1% compared to the average annual load reduction of 1.2%, and sediment loads decreased an estimated 0.9% compared to the average annual load reduction of 0.3%.

The best available data for 2020 Progress has been impacted by challenges select states face with their BMP tracking and reporting. In Delaware, the 2020 modeled loads are not reflective of true BMP implementation levels in Delaware as the state is working through issues with its BMP data warehouse. Delaware will remedy these issues in 2021-2022 to represent BMP implementation levels more accurately within the state.

The Chesapeake Bay Program’s nutrient pollution load estimates were generated using the CAST-2019 version of the Phase 6 model (also known as CAST-19) and wastewater discharge data reported by jurisdictions and calibrated using monitoring data. For detailed descriptions of CAST, please visit the CAST Model Documentation website.

Jurisdictions have described the steps they are taking to reduce pollution and achieve the Bay TMDL allocations in their respective Watershed Implementation Plans (WIPs). Jurisdictions developed and submitted Phase I WIPs in 2010, Phase II WIPs in 2012 and Phase III WIPs in 2019. Final planning targets for sediment and source sectors have been established since 2018’s reporting period. All other planning target loads were adjusted after the jurisdictions’ Phase III Watershed Implementation Plans (WIPs) were finalized in 2019 using the same process that established the Bay Total Maximum Daily Load (TMDL) in 2010. In 2021, New York’s amendment to their Phase III WIP was finalized, meeting their adjusted planning target loads.

Resource availability, location and other factors can influence a jurisdiction’s decision and ability to implement certain practices in certain sectors. More information about nitrogen, phosphorus and sediment loads and practices can be found on the CAST website. Programmatic milestones are maintained and updated every two years on the websites of each jurisdiction: Delaware, Maryland, New York, Pennsylvania, Virginia, West Virginia and the District of Columbia. The next milestone period is 2020-2021.

The Chesapeake Bay Program also uses water quality monitoring data to track the partnership’s progress towards attaining water quality standards and to examine trends in reducing nitrogen, phosphorus and sediment in the watershed.

Learn About Factors Influencing Progress

Participating partners have described the steps they will take to achieve the 2025 Watershed Implementation Plan (WIP) outcome in their individual WIPs. To track the achievement of these outcomes, partners have committed to:

• Collecting, verifying and reporting BMP data;
• Evaluating the effectiveness of pollution controls;
• Enhancing water quality monitoring efforts; and
• Adhering to the TMDL Accountability Framework.

Monitoring and assessing progress toward the 2017 WIP outcome occurred through the 2017 Midpoint Assessment. This review of our progress led to enhanced modeling tools that addressed emerging issues like climate change and the TMDL Accountability Framework helps provide confidence that the necessary pollution reductions will occur to achieve the 2025 WIP outcome.

As part of the Chesapeake Bay Program’s partnership-wide implementation of adaptive management, progress toward this outcome was reviewed and discussed by the Management Board in August of 2020. It will be reviewed and discussed by the Management Board again in August 2022.

Download Management Strategy (.pdf)

Chesapeake Bay Program partners have committed to taking a series of specific actions that will support the management approaches listed above.

Learn About Logic & Action Plan

The Water Quality Goal Implementation Team leads the effort to achieve this outcome. It works in partnership with the Vital Habitats Goal Implementation Team and the Scientific, Technical Assessment and Reporting Team.

Participating partners include:

• State of Delaware
• State of Maryland
• State of New York
• Commonwealth of Pennsylvania
• Commonwealth of Virginia
• State of West Virginia
• District of Columbia
• Chesapeake Bay Commission
• Natural Resources Conservation Service (U.S. Department of Agriculture)
• U.S. Army Corps of Engineers
• U.S. Department of Defense
• U.S. Department of Homeland Security
• U.S. Environmental Protection Agency
• U.S. Geological Survey