Progress

Pollution-reducing practices were in place by 2017 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 the 2009 baseline established by the U.S. Environmental Protection Agency (EPA) as part of the Chesapeake Bay Total Maximum Daily Load (Bay TMDL).

According to the Chesapeake Bay Program’s Watershed Model Phase 5.3.2, 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.

This outcome was established as a midpoint assessment from the 2009 baseline and the 2025 goal described in the Bay TMDL and these results mark completion of this outcome. In July 2018, pollution reduction targets were revised using updated data and new science in a Phase 6 version of the Chesapeake Bay Program’s Watershed Model. Visit the 2025 Watershed Implementation Plan (WIP) Outcome page for our continued progress toward pollution reduction targets for the year 2025.

Interactive Charts

Modeled Nitrogen Loads to the Chesapeake Bay (1985-2017)

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

Modeled Phosphorus Loads to the Chesapeake Bay (1985-2017)

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

Modeled Sediment Loads to the Chesapeake Bay (1985-2017)

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

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. Estimated pollution loads, milestones and targets by jurisdiction and sector are summarized in the table below. More information about pollution loads at the basin and river segment level are available for download.


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 WIPs in 2010, Phase II WIPs in 2012 and Phase III WIPs in 2019.

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 also uses water quality monitoring data to report the partnership’s progress in attaining water quality standards and to examine trends in reducing nitrogen, phosphorus and sediment in the watershed.

Management Strategy

Participating partners described the steps they would take to achieve the 2017 Watershed Implementation Plans (WIPs) outcome in their individual Phase II WIPs. To track the achievement of these outcomes, partners 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 this outcome occurred through the 2017 Midpoint Assessment. This assessment led to enhanced modeling tools that address emerging issues like climate change and future tracking of the necessary pollution reductions will occur through the 2025 WIP outcome.

As part of the Chesapeake Bay Program’s partnership-wide implementation of adaptive management, completion of this outcome was also reviewed and discussed by the Management Board in May of 2018. Please visit the 2025 Watershed Implementation Plan (WIP) Outcome page for future updates.

Logic & Action Plan

Chesapeake Bay Program partners committed to taking a series of specific actions that supported the management approaches listed above. Continuing work to reduce nutrient and sediment loads to achieve applicable water quality standards can be found on the 2025 WIP outcome page.

Participating Partners

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

Participating partners included:

  • 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