Recent Progress: Increase

According to data submitted by Delaware, Maryland, Virginia and the District of Columbia to the U.S. Environmental Protection Agency in 2020, 78% of the Chesapeake Bay’s tidal segments were partially or fully impaired by toxic contaminants. This is a decrease from 2018, when 83% of the Chesapeake Bay’s tidal segments were reported as partially or fully impaired by toxic contaminants. Since 2010, the listings of impaired waters under Section 303(d) of the Clean Water Act used in this indicator have shown an increase in the observation of toxic contaminant impairments except for 2020’s short-term decrease. The recent improvement may be due to decreased loads of contaminants as a result of best management practices or remedial activities in the ecosystem, or it may be due to the breakdown of the pollutants over time.

Outlook: Off Course

The Toxic Contaminants Policy and Prevention Outcome is off course. While 2020 showed a slight improvement, the outcome remains far from the Toxic Contaminants Goal of observing no impairments by toxic contaminants. Between 2010 and 2018, each biennial update showed a higher number of tidal segments in the Chesapeake Bay that are listed as fully or partially impaired due to toxic contaminants. Also, the 2020 data set is the first to include some assessment of per- and polyfluoroalkyl substances (PFAS) with the first jurisdiction identification of a PFAS-related impairment. Given PFAS’s status as a pollutant of emerging concern and new health advisory limits that will likely trigger fish consumption advisories, jurisdictions’ reporting of PFAS impairment is expected to increase in the next few cycles.

While chemical contamination is often characterized as a localized problem occurring in “hot spots” or “regions of concern,” pollutants like metals, polychlorinated biphenyls (PCBs) and priority organics exceed water quality criteria in at least part of each tidal tributary that delivers water to the central channel of the Bay. Increasing understanding of toxic contaminants is critical to the drafting of policy and prevention approaches that will reduce their effects on living resources.

Toxic contaminants can negatively affect the survival, growth and reproduction of fish and wildlife, but they also pose a threat to human health when such contaminated organisms are a component of human diets. The human health risks are due to a process termed bioaccumulation, which occurs when persistent, elevated concentrations of contaminants in the water and bottom sediment build up in an organism’s tissue through its diet and then become further concentrated up the food chain, affecting other fish and, ultimately, humans. Management actions undertaken through state Total Maximum Daily Loads (TMDLs) are essential to achieve long-term positive change in the level of toxic contamination.

Learn About Factors Influencing Progress

Management Strategy

To achieve this outcome, Chesapeake Bay Program partners have committed to:

  • Supporting programs that monitor the occurrence of PCBs.
  • Supporting the development, evaluation and implementation of toxic contaminant Total Maximum Daily Loads (TMDLs).
  • Compiling data for enhanced regulatory programs.
  • Developing guidance documents for the control and reduction of PCBs in regulated stormwater and wastewater.
  • Developing capacity for tracking-down PCB sources.
  • Coordinating educational workshops to increase public knowledge of the impacts PCBs can have on human health, the risks of consuming contaminated fish and the technologies available for sediment remediation.
  • Coordinating voluntary programs to track current use sources of PCBs and phase out PCB-containing equipment.
  • Improving the information available for PCB reduction strategies.

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 September of 2022. It will be reviewed and discussed by the Management Board again in August 2024.

Download Management Strategy (.pdf)

Logic & Action Plan

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


  • Supporting jurisdictional monitoring programs for PCB occurrence to assess the need for new TMDLs at the local level.
  • Encouraging the use of novel methods to improve the characterization of PCB sources.
  • Identifying barriers and opportunities related to laboratory method consistency for contaminated sites, wastewater and regulated and unregulated stormwater dischargers.
  • Using data compilations, monitoring results, guidance documents and other outputs of this management strategy to implement local TMDLs.
  • Improving the ability to track local TMDL development and implementation progress.
  • Supporting the development of systems to compile information with which to determine if additional monitoring requirements are necessary to support TMDL development and implementation.
  • Developing a desktop geographic information system tool to help the Hazardous Site Cleanup Division of the EPA identify potential on-land sources of contamination in the region.
  • Working with the Hazardous Site Cleanup Division and Toxic Contaminants Workgroup to evaluate sites and identify industries or processes that used PCBs so that the Superfund, Brownfields and Resource Conservation and Recovery Act programs can better focus resources on identifying and investigating these kinds of sites.
  • Working with the National Pollutant Discharge Elimination System Permits Branch to ensure permits are consistent with local TMDLs and PCB Wasteload Allocations, clear and enforceable.
  • Working through the EPA Land and Chemicals Toxics Program to ensure compliance with Toxic Substances Control Act regulations related to PCBs.
  • Investigating the development of a voluntary action program to reduce the presence of fluorescent light ballasts and other equipment containing PCBs. Program participants would be instructed on using the EPA’s Environmental Justice Screening Tool to identify the location of equipment relative to areas with underprivileged populations and informed about remediating on-site PCB contamination.
  • Supporting research on cost-effective tools for tracing PCB contaminant source studies and providing a mechanism for municipalities to share lessons learned.

Recently Completed


  • Updated the PCB story map, which shows the extent of PCB impairments, the impaired areas that have TMDLs in place, the impaired areas that have PCB TMDLs under development and the impaired areas where there is no current or planned TMDL. The map helps the partnership discuss and develop strategic directions.


  • Shared the results of research on the state of PCBs in wastewater treatment systems, including the partitioning of PCBs to biosolids.
  • Initiated a program that brings together PCB strategy leaders from watersheds across the country to share their approaches, lessons learned and recommendations so that many watershed restoration programs that are addressing PCBs can benefit from collective learning.
  • Established a council of program leads in EPA Region 3 that have some level of statutory authority related to controlling PCBs.

Learn About Logic & Action Plan

Participating Partners

The Water Quality Goal Implementation Team leads the effort to achieve this outcome.

Participating partners include:

  • Delaware Department of Natural Resources and Environmental Control (State of Delaware)
  • Maryland Department of the Environment (State of Maryland)
  • Maryland Department of Natural Resources (State of Maryland)
  • New York Department of Environmental Conservation (State of New York)
  • Pennsylvania Department of Environmental Protection (Commonwealth of Pennsylvania)
  • Virginia Department of Environmental Quality (Commonwealth of Virginia)
  • West Virginia Department of Environmental Protection (State of West Virginia)
  • Department of Energy and Environment (District of Columbia)
  • Chesapeake Bay Commission
  • National Oceanic and Atmospheric Administration
  • U.S. Department of Homeland Security
  • U.S. Environmental Protection Agency
  • U.S. Fish and Wildlife Service
  • U.S. Geological Survey