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How Does It Work? Ensuring Results

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  • Ensuring Results
  • Watershed Implementation Plans
  • Establish TMDL
  • Two - Year Milestones
  • Monitor Progress
  • Federal Steps
  • Timeline
  • Trading and Offsets
  • Agriculture

Click on a Box for more info about how EPA and the States are ensuring that progress is made in cleaning up the Chesapeake Bay and Local waters.

Graphic for Ensuring Results. Click on each box for more information about each step in the process. Potential actions or "consequences" Establishing the Bay TMDL Read about the 2-Year Milestones Monitoring Progress Get more about the Watershed Implementation Plans
Learn about Watershed Implementation Plans
  • Overview of WIPS
  • Phase I WIPs
  • Phase II WIPs
The PDF links on this page can be viewed with the Adobe PDF reader.
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  • The Chesapeake Bay TMDL Watershed Implementation Plans identify how the Bay jurisdictions are putting measures in place by 2025 that are needed to resore the Bay, and by 2017 to achieve at least 60 percent of the necessary nitrogen, phosphorus and sediment reductions compared to 2009. Much of this work already is being implemented by the jurisdictions consistent with their Phase I WIP commitments, building on 30 years of Bay restoration efforts.

  • EPA will maintain close oversight over each of the states' and the District's programs in all sectors to make sure they are implementing the pollution control plans, are on schedule for meeting water quality goals and are achieving two-year milestones. This ongoing partnership is restoring clean water to the thousands of streams and rivers that make up the Chesapeake Bay watershed and improving the quality of life and economy for the 17 million people who live in it.

  • The Chesapeake Executive Council, Principals' Staff Committee AND EPA have all expressed a need for acceleration of progress toward restoration of the Chesapeake Bay, a sharper emphasis on explicit actions, and greater transparency and accountability in these efforts. The Watershed Implementation Plans are a key element of this approach.

  • In combination with the two-year milestones and follow-up progress reports to the public, these plans also fulfill the heightened expectation within the President's Executive Order 13508: Chesapeake Bay Protection and Restoration to create a new accountability framework that guides local, state and federal water quality restoration efforts.

  • EPA is providing technical and financial support and has set clear expectations to help watershed states and the District develop their plans.

  • The Chesapeake Bay TMDL allocations for each sector are based largely on the Phase I WIPS.

  • Final Phase I Watershed Implementation Plans were submitted to EPA by the six watershed states and the District of Columbia beginning November 29, 2010. The WIPs were designed to provide a roadmap for how and when a jurisdiction intends to meet its pollutant allocations under the Bay TMDL. View the Final Phase I WIPS for Exit EPA Click for Disclaimer Delaware, District of Columbia, Maryland, New York, Pennsylvania, Virginia, West Virginia.

  • The Phase I WIPs were reviewed by a team of EPA sector specialists based on detailed expectations provided by EPA in November 2009 and supplemented in April 2010 and extensive interaction with the jurisdictions since the submittal of draft WIPs in early September 2010. The WIPs needed to meet the lower pollution limits for that jurisdiction and provide reasonable assurance that the actions identified would achieve the reductions, particularly for non-permitted sources like runoff from agricultural lands and stormwater from urban and suburban lands. The final WIPs represented significant improvements over the draft WIPs, enabling EPA to reduce and remove most federal "backstops" that had been included in the draft TMDL. View the Phase i Evaluations for Delaware, District of Columbia, Maryland, New York, Pennsylvania, Virginia and West Virginia.

District of Columbia | Delaware | Maryland | New York | Pennsylvania |
Virginia | West Virginia

  • On May 30, 2012, EPA provided its evaluations of the Final Phase II Watershed Implementation Plans (WIPs) from Pennsylvania, West Virginia, Delaware, Maryland, Virginia, and the District of Columbia as part of the Chesapeake Bay watershed restoration effort. View the letters and evaluations for Delaware (PDF) (6pg, 305K), District of Columbia (PDF) (6pg, 291K), Maryland (PDF) (6pg, 360), New York (PDF) (7pg, 589K), Pennsylvania (PDF) (8pg, 560K), Virginia (PDF) (8pg, 453K), West Virginia (PDF)(6pg, 364K).

  • EPA received Final Phase II Watershed Implementation Plans (WIPs) from Bay jurisdictions on March 30, 2012, as progress continues throughout the watershed to restore clean water to the Chesapeake Bay and its vast network of local waters. View the final plans for District of Columbia, Delaware , Maryland, New York, Pennsylvania, Virginia, West Virginia. EPA will assess the final plans to ensure they meet EPA expectations. For their Phase II WIPs, EPA asked jurisdictions to make key stakeholders — local governments, conservation districts, farmers, builders and others — aware of their roles in cleaning up the region's waterways, to strengthen pollution-reduction strategies for any sectors subject to federal enhanced oversight or backstop actions based on the Phase I WIPs and the Bay TMDL issued in 2010.

  • EPA Reviewed the jurisdictions’ Draft Phase II Watershed Implementation Plans (WIPs) and 2012-2013 two-year milestones and provided feedback on Feb. 15, 2012. The Phase II WIPs and the two-year milestones are important elements in meeting the commitment by the Chesapeake Bay Program partnership to having all of the needed pollution control measures in place to fully restore the Bay by 2025. View the Letters (PDF Portfolio) (7 documents, 4.6M) and reviews for District of Columbia (PDF) (4pg, 30K), Delaware (PDF) (4pg, 32K), Maryland (PDF) (5pg, 32K), New York (PDF) (5pg, 151K), Pennsylvania (PDF) (6pg, 171K), Virginia (PDF) (5pg, 33K), West Virginia (PDF) (5pg, 33K).

Learn How EPA established the Bay TMDL

  • On December 29, 2010, the U.S. Environmental Protection Agency established the Chesapeake Bay Total Maximum Daily Load (TMDL), a historic and comprehensive “pollution diet” with rigorous accountability measures to drive sweeping actions to restore clean water in the Chesapeake Bay and the region’s streams, creeks and rivers. Read more about the Bay TMDL

  • The Chesapeake Bay TMDL is the largest and most complex TMDL ever developed, involving six states and the District of Columbia and the impacts of pollution sources throughout a 64,000-square-mile watershed.

  • The Bay TMDL – actually a combination of 92 smaller TMDLs for individual Chesapeake Bay tidal segments – includes limits on nitrogen, phosphorus and sediment sufficient to achieve state clean water standards for dissolved oxygen, water clarity, underwater Bay grasses and chlorophyll-a, an indicator of algae levels.

Read about the TMDL's Two Year Milestones

  • ON JANUARY 15, 2015, EPA RECEIVED THE TWO-YEAR MILESTONES PROGRESS UPDATES FOR THE 2014-2015 PROGRAMMATIC MILESTONES from Chesapeake Bay jurisdictions as part of the "pollution diet" or Bay TMDL. These progress updates are expected per the Two-Year Milestone Guide that was shared in July 2011. Chesapeake Bay jurisdictions will provide progress updates for programmatic milestones at the midpoint and the end of the milestone period. Read the jurisdiction's milestones progress updates:
  • On January 6, 2012, EPA received the first set of two-year milestones from Chesapeake Bay jurisdictions as part of the “pollution diet” or Bay TMDL. The milestones outline steps the Bay jurisdictions will take in the next two years to reduce nitrogen, phosphorus and sediment pollution to the Chesapeake Bay, and what reductions those measures will achieve. Read the jurisdiction’s milestones:

  • Also on January 6, six federal agencies on the Federal Leadership Committee for the Chesapeake Bay, including EPA, issued their own two-year water quality milestones to support jurisdictions in meeting their reduction goals. Read the federal agencies’ milestones.

  • The two-year milestones represent key check-in points on the way to having all pollution reduction measures in place by 2025 to restore the Bay and its tidal rivers, with controls in place by 2017 that would achieve 60 percent of the necessary reductions. The milestones are a critical part of an accountability framework agreed upon by EPA and the jurisdictions to assure progress.

  • EPA evaluated the jurisdictions’ 2012-2013 two-year milestones and their Draft Phase II Watershed Implementation Plans and provided feedback on Feb. 15, 2012. View the Evaluations for District of Columbia (PDF) (4pg, 30K), Delaware (PDF) (4pg, 32K), Maryland (PDF) (5pg, 32K), New York (pending), Pennsylvania (PDF) (6pg, 171K), Virginia (PDF) (5pg, 33K), West Virginia (PDF) (5pg, 33K)

  • The first round of Bay TMDL-related milestones continues the Chesapeake Executive Council's commitment to accountability for near-term progress established with an initial set of milestones in 2009.
Read the Two-Year Milestone Guide (PDF) (9pg, 473K)

Learn how EPA will Monitor Progress

    • EPA will have ongoing oversight of all state programs to assure they are on track to meet the goals of their Watershed Implementation Plans and their two-year milestones.

    • EPA on January 28, 2011 launched a new feature of ChesapeakeStat a website developed by the Chesapeake Bay Program to assess Bay restoration activity. This new feature, the Chesapeake Bay TMDL Tracking and Accounting System (BayTAS), will track and verify progress in meeting cleanup commitments under the Chesapeake Bay Total Maximum Daily Load, or “pollution diet.”

      Bay TAS initially included the 2009 baseline levels of nitrogen, phosphorus and sediment pollution to the Bay, and the allocations of pollutant reductions called for in the final Bay TMDL. This information is displayed geographically by jurisdiction (six states and the District of Columbia), by water body segment and by source sector. Jurisdiction-specific data reflecting progress – measured against the 2009 figures – is being added to the system on an ongoing basis.

      BayTAS meets a commitment of the federal strategy to implement President Obama’s Chesapeake Bay Executive Order and EPA’s 2010 settlement agreement with the Chesapeake Bay Foundation. BayTAS will help ensure that the Chesapeake Bay partners and the public have a transparent means of tracking, accounting and verifying pollution reductions as the Bay TMDL is implemented.

EPA will employ steps if progress is inadequate

  • EPA will carefully review programs and permits in all jurisdictions. EPA’s goal is for jurisdictions to successfully implement their WIPs, but the agency is prepared to take necessary actions in all jurisdictions for insufficient WIP implementation or pollution reductions. Federal actions can be taken at any time, although EPA will engage particularly during two-year milestones, the 2017 midpoint assessment, and Phase III WIP development. Potential actions include:

    • Expanding coverage of NPDES permits to sources that are currently unregulated.
    • Increasing oversight of state-issued NPDES permits.
    • Requiring additional pollution reductions from federally regulated sources.
    • Increasing federal enforcement and compliance.
    • Prohibiting new or expanded pollution discharges.
    • Redirecting EPA grants.
    • Revising water quality standards to better protect local and downstream waters.
    • Discounting nitrogen, phosphorus and sediment reduction progress if jurisdiction cannot verify proper installation and management of controls.
Timeline for the Chesapeake Bay Action plan. Click on each segment for more information. See the Events in 2009 See the Events in 2010 See the Events in 2011



  • July 1 - EPA assigns nitrogen and phosphorous allocations to the six watershed states and the District of Columbia by major river basin, and includes a temporary reserve for any shift in loads that may occur from two model updates (nutrient management effectiveness and suburban land characteristics).

  • August 15 - EPA assigns sediment allocations to the states and the District by major river basin.

  • September 1 - The states and the District complete their draft Phase I Watershed Implementation Plans.

  • September 24 - EPA issues a draft Bay TMDL for 45-day public comment.

  • September 24- November 8 - Bay TMDL public comment period includes a series of public meetings and webinars throughout the watershed.

  • November 29 - The states and the District complete their final Phase I Watershed Implementation Plans.

  • December 29 - EPA establishes the Bay TMDL.


  • December 15 - Jurisdictions submit draft Phase II Watershed Implementation Plans.

  • December 31 - The first set of two-year milestones is completed.


  • February 15 - EPA provides formal comments on draft Phase II Watershed Implementation Plans.

  • March 30 - Jurisdictions submit final Phase II Watershed Implementation Plans.

Future Actions

  • Prior to 2017, EPA reviews the full suite of the partnership’s Bay models based on the best available science and decision-support tools and considers whether updated models should be developed to support Phase III implementation plans and potential modifications to Bay TMDL allocations.

  • In 2017, the states and the District submit draft Phase III Watershed Implementation Plans by June 1 and final plans by Nov. 1 with a focus on ensuring that all practices are in place by 2025 as need to fully restore the Bay and its tidal waters.

  • EPA modifies the Bay TMDL, if necessary, in December 2017.

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  • Overview of Trading and Offsets
  • Trading and Offset TMDL Provisions and EPA Policy
  • Bay Trading and Offset Activities
  • Bay Jurisdictions Trading and Offset Programs
  • Additional Resources
  • Provide Feedback on Technical Memoranda

On December 29, 2010, the U.S. Environmental Protection Agency (EPA) established the Chesapeake Bay Total Maximum Daily Load (TMDL). A TMDL calculates the maximum amount of a pollutant that a waterbody can receive while still meeting water quality standards. The Chesapeake Bay TMDL is the largest, most complex TMDL in the country, covering a 64,000-square-mile area across seven jurisdictions for the tidal segments and tributaries of the Chesapeake Bay that are impaired due to excessive loads of nitrogen, phosphorus and sediment. The Chesapeake Bay TMDL allocates loading caps to sources contributing those pollutants in seven jurisdictions of the Bay watershed—Delaware, the District of Columbia, Maryland, New York, Pennsylvania, Virginia, and West Virginia.

The Bay jurisdictions bear the responsibility for implementing the Bay TMDL. EPA expects that new or increased loadings of nitrogen, phosphorous and sediments in the Chesapeake Bay watershed will be offset by loading reductions and credits generated by other sources.  Beyond permitting and nonpoint source controls, water quality trading is one approach that Bay jurisdictions may use to achieve the load reduction requirements established under the Bay TMDL.

Water quality trading is a market-based approach, providing an economic incentive for voluntary pollutant reductions from point and nonpoint sources of pollution, to improve and preserve water quality. Trading can provide greater efficiency in achieving water quality goals in watersheds by allowing one source to meet its regulatory obligations by using pollutant reductions created by another source with lower pollution control costs.

EPA recognizes that a number of Chesapeake Bay jurisdictions are already implementing water quality trading programs. EPA supports implementation of the Bay TMDL through water quality trading programs, as long as they are established and implemented in a manner consistent with the Clean Water Act (CWA), its implementing regulations, EPA’s 2003 Water Quality Trading Policy (PDF) (11pp, 110K) and the 2007 Water Quality Trading Toolkit for NPDES Permit Writers. EPA does not support any trading activity that would delay or weaken implementation of the Bay TMDL, that is inconsistent with the assumptions and requirements of the TMDL, or that would cause the combined point source and nonpoint source loadings covered by a trade to exceed the applicable loading cap established by the TMDL.

TMDL Provisions
In Section 10 (PDF) (8 pp, 191K) of the Chesapeake Bay TMDL, EPA explains how Bay jurisdictions may accommodate new or increased loadings of nitrogen, phosphorus, and sediment either through a specific TMDL allocation or by offsetting those loadings with quantifiable and accountable reductions necessary to implement applicable Water Quality Standards in the Bay and its tidal tributaries.

In Appendix S (PDF) (6 pp, 191K) of the Chesapeake Bay TMDL, EPA discusses a number of definitions and common elements that EPA encourages and expects the jurisdictions to include and implement in their offset programs. EPA believes the definitions and common elements in Appendix S also constitute important components of trading programs in the Chesapeake Bay watershed. EPA anticipates using these Appendix S definitions and elements in reviewing jurisdictions’ trading programs.

EPA’s Water Quality Trading Policy, finalized in 2003, endorses trading as an economic incentive for voluntary pollutant reductions from point and nonpoint sources of pollution to improve and preserve water quality and as a way to achieve ancillary environmental benefits such as creation of habitat.

EPA Trading and Offset Workplan
EPA is developing a comprehensive workplan for trading and offsets that outlines key products and activities to support the work of Chesapeake Bay jurisdictions managing trading programs. The workplan is being developed in coordination with the Chesapeake Bay Program Trading and Offsets Workgroup (TOWG). The TOWG charge is to focus and support the implementation of practices, policies, and programs within the realm of nutrient and sediment trading and offsets that will assist efforts to restore water quality in the Chesapeake Bay and its tidal tributaries.

Technical Memoranda
To assist the Bay jurisdictions in implementing their action plans and strengthening their programs, EPA is developing a series of technical memoranda (TMs). The memoranda will also provide EPA and the jurisdictions with a framework for determining whether program elements meet EPA expectations. Drafts of the memoranda will be shared with the Bay jurisdictions, the Trading and Offsets Workgroup (TOWG), the Chesapeake Bay Program Science and Technical Advisory Committee, the US Department of Agriculture, and interested stakeholders for stakeholder input. A list of all proposed TMs is shown below. This list will be updated with links to draft and final documents as they become available. Click the "Provide Feedback on Technical Memoranda" tab above to send your feedback.

Technical Memoranda Development – Proposed Schedule (PDF) (1page, 151K)
Projected dates reflected in this schedule should be considered as target dates and may shift depending upon the newly identified priorities, and available resources.

EPA Review of Bay Jurisdictions’ Trading and Offset Programs
EPA completed its first review of the Chesapeake Bay watershed jurisdictions’ offset and trading programs to meet target load reductions of nitrogen, phosphorus and sediment, as part of the Bay TMDL. EPA provided drafts of its reviews to the jurisdictions and interested stakeholders in December 2011.

Get the final reports (PDF Portfolio) (7 documents, 3M), letters to jurisdictions (PDF Portfolio) (7 documents, 825K) and comments received on the drafts (PDF Portfolio) (19 documents, 3M).

EPA continues to work with the Bay jurisdictions to address areas of concern identified in the final reports. EPA has asked each jurisdiction to prepare a Sector Load Growth Demonstration using the Sector Load Growth technical Memorandum above as a guide.  Listed below are the Sector Load Demonstrations prepared by the seven jurisdictions.

In addition to state-specific Chesapeake Bay TMDL information available through EPA, the Bay jurisdictions that have trading and/or offset programs in place have individual websites as indicated below.

District of Columbia
The District Department of the Environment (DDOE) is in the process of establishing an offset program – a proposed rulemaking on Stormwater Management and Soil Erosion and Sediment Control was published on August 10, 2012.

At this time, Delaware does not have a water quality trading-specific website. However, the Delaware Department of Natural Resources and Environmental Control’s Watershed Assessment Section reports on water quality and the TMDL.

Information on Maryland’s nutrient trading program can be found through the Maryland Department of Agriculture.

New York
At this time, New York does not have a water quality trading-specific website. However, the New York Department of Environmental Conservation reports on water quality and the TMDL.

Information on Pennsylvania’s nutrient trading program can be found through the Pennsylvania Department of Environmental Protection.

Information on Virginia’s nutrient trading program can be found through the Virginia Department of Environmental Quality. Additional information is available through the Virginia Nutrient Credit Exchange Association.

West Virginia
At this time, West Virginia does not have a water quality trading-specific website. However, the West Virginia Department of Environmental Protection reports on water quality and the TMDL.

Additional EPA Resources:
Water Quality Trading – EPA Main Page

Water Quality Trading Assessment Handbook provides an analytical framework to assess the conditions and water quality problem(s) in any specific watershed and to determine whether water quality trading could be used effectively to achieve a cleaner watershed.

Water Quality Trading Toolkit for NPDES Permit Writers is EPA’s first “how-to” manual on designing and implementing water quality trading programs. The Toolkit helps National Pollutant Discharge Elimination System (NPDES) permitting authorities incorporate trading provisions into permits. It will help improve the quality and consistency of all trading programs across the nation.

Web-based Water Quality Trading Training Modules are a series of six recorded presentations based on training workshops EPA conducted after releasing The Water Quality Trading Toolkit for Permit Writers. These recorded presentations are useful for those who wish to become familiar with key water quality trading concepts.

State and Individual Trading Programs – National Map

Mid-Atlantic TMDLs – provides a comprehensive list of TMDLs developed by the EPA in the Mid-Atlantic region, organized by waterbody, approval date, pollution type and jurisdiction.

2001 Chesapeake Bay Trading Guidelines (PDF) (87 pp, 2.5MB) – available for historical references purposes only, this document was developed prior to EPA’s national policy on water quality trading and did not serve as a source document in the development of the Bay TMDL. It articulates pre-TMDL fundamental principles and guidelines for nutrient trading in the Chesapeake Bay Watershed, and was intended to be used voluntarily as a guide for those Bay jurisdictions that choose to establish nutrient trading programs.

Other Resources:
Water Quality Trading – World Resources Institute

NutrientNet – NutrientNet is a suite of web-based tools used to facilitate market-based approaches to improving water quality. NutrientNet has been used extensively for water quality trading programs, but it also has been used for other market-based approaches.

In It Together – Water quality trading lessons learned report developed by the Willamette Partnership, Pinchot Institute for Conservation, and World Resources Institute, prepared for the U.S. Department of Agriculture (USDA) Office of Environmental Markets.

Nutrient Credit Trading for the Chesapeake Bay – An economic study prepared by the Chesapeake Bay Commission.

USDA Office of Environmental Markets – the Office of Environmental Markets (OEM) supports the development of emerging markets for carbon sequestration, water quality, wetlands, biodiversity, and other ecosystem services. The Chesapeake Bay Environmental Management Team (CB EMT) was involved in examining some of the issues and considerations regarding eligibility requirements for landowners who may wish to generate credits for sale in a water quality market related to the Chesapeake Bay TMDL.

Please contact Bob Rose (rose.bob@epa.gov) or Pat Gleason (gleason.patricia@epa.gov) to provide feedback on technical memoranda or with any other trading and offsets questions.


Agricultural Assessments

  • EPA conducts periodic reviews of state programs as part of its oversight responsibilities under the Clean Water Act.  Starting in 2013, EPA conducted assessments of animal agriculture programs in the six Chesapeake Bay jurisdictions.  EPA’s assessments evaluated the jurisdictions’ implementation of programs to ensure reductions in the amount of nitrogen, phosphorus, and sediment pollution going to waterways within the Bay Watershed, as called for under the Chesapeake Bay Total Maximum Daily Load (TMDL).  The assessments looked at the jurisdictions’ implementation of federal and state regulatory programs, as well as voluntary incentive-based programs to meet the nutrient and sediment reduction commitments in the jurisdictions’ Watershed Implementation Plans (WIPs).  EPA will use these assessments, along with its ongoing Chesapeake Bay TMDL evaluations, to ensure that the jurisdictions have the programs, policies, and resources necessary to succeed with their plans to meet the Chesapeake Bay TMDL.  In March 2015, EPA released its completed evaluations of animal agriculture programs in New York, Pennsylvania, and Virginia.  Later in 2015, EPA will complete and release similar reports on animal agriculture programs in Delaware, Maryland and West Virginia.

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