According to the Chesapeake Bay Program’s Watershed Model, pollution controls put in place in the Chesapeake Bay watershed between 2009 and 2017 lowered nitrogen loads 11 percent, phosphorus loads 21 percent and sediment loads 10 percent. Experts attribute this drop in estimated pollution loads to technological upgrades at wastewater treatment plants and the increased implementation of agricultural best management practices (BMPs). While the Chesapeake Bay Program partnership has exceeded its 2017 pollution reducing targets for phosphorus and sediment, it fell short of its pollution reducing target for nitrogen by 15 million pounds. The implementation of BMPs in the agricultural and urban sectors will need to accelerate to close this gap.

Interactive Charts

Modeled Nitrogen Loads to the Chesapeake Bay (1985-2025)

Loads simulated using Watershed Model (Phase 5.3.2) and jurisdiction-reported data on wastewater discharges.

Modeled Phosphorus Loads to the Chesapeake Bay (1985-2025)

Loads simulated using Watershed Model (Phase 5.3.2) and jurisdiction-reported data on wastewater discharges.

Modeled Sediment Loads to the Chesapeake Bay (1985-2025)

Loads simulated using Watershed Model (Phase 5.3.2) and jurisdiction-reported data on wastewater discharges.

The U.S. Environmental Protection Agency (EPA) established pollution reduction targets for the year 2025 as part of the Chesapeake Bay Total Maximum Daily Load (Bay TMDL). While the Bay TMDL also included pollution reduction targets for the year 2017, the seven watershed jurisdictions defined their pollution reducing commitments in the form of 2017 Milestones. Estimated pollution loads, milestones and targets are summarized in the table below and available for download.

Pollution-reducing practices are in place to achieve 40 percent of the nitrogen reductions, 87 percent of the phosphorus reductions and 67 percent of the sediment reductions necessary to attain applicable water quality standards as compared to 2009, the year before the EPA established the Bay TMDL.

Jurisdictions describe the steps they will take to reduce pollution and achieve the Bay TMDL allocations in their respective Watershed Implementation Plans (WIPs). Jurisdictions developed and submitted Phase I and Phase II WIPs in 2010 and 2012, respectively. Jurisdictions continue to establish short-term pollution reducing goals in the form of two-year milestones and will develop and submit Phase III WIPs in 2018. The EPA is expected to release its evaluations of jurisdictional progress toward their individual 2016-2017 milestones and the watershed-wide Bay TMDL in the summer of 2018.

Resource availability, location and other factors can influence a jurisdiction’s decision and ability to implement certain practices in certain sectors. A full listing of the practices to which each jurisdiction has committed is available for download. Programmatic milestones are maintained on the websites of each jurisdiction: Delaware, Maryland, New York, Pennsylvania, Virginia, West Virginia and the District of Columbia.

The Chesapeake Bay Program’s pollution load estimates were generated using the Watershed Model (Phase 5.3.2) and wastewater discharge data reported by jurisdictions and calibrated using monitoring data. In addition, the state of Maryland uses a Chesapeake Bay Program-approved Supplemental Wastewater Indicator to track its progress toward wastewater planning targets. More information about nitrogen, phosphorus and sediment loads at the river segment level is available through the TMDL Tracker. The Chesapeake Bay Program also uses BMP Expert Panels to estimate best management practice effectiveness and water quality monitoring data to report the partnership’s progress in attaining water quality standards and examine trends in reducing nitrogen, phosphorus and sediment in the watershed.

Management Strategy

Participating partners have described the steps they will take to achieve the 2017 and 2025 Watershed Implementation Plans (WIPs) outcomes in their individual WIPs. To track the achievement of these outcomes, partners have committed to:

  • Collecting, verifying and reporting best management practice data;
  • Evaluating the effectiveness of pollution controls;
  • Enhancing water quality monitoring efforts;
  • Conducting a 2017 Midpoint Assessment; and
  • Adhering to the TMDL Accountability Framework.

Monitoring and assessing progress toward the outcome will occur through the 2017 Midpoint Assessment (which will review our progress, enhance our modeling tools and address emerging issues like climate change) and the TMDL Accountability Framework (which will help provide confidence that the necessary pollution reductions will occur).

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 May of 2018.

Logic & Action Plan

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

Participating Partners

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