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Maryland State Government Maryland Department of the Environment

Total Maximum Daily Load (TMDL) Implementation 

 Chesapeake Bay TMDL and Watershed Implementation Plan (WIP)

General TMDL Implementation

Other Resources

Implementing MD's WIP

Accounting for Growth

EPA Bay TMDL (leaving MDE)

Chesapeake Bay TMDL and MD's Blueprint for Restoration 

Phase I WIP and Phase II WIP  Documents

2012-2013 2014-2015

Phase II WIP Development Support (Archive)

Federal Laws and Regulations

Water Quality Assessment Report [303(d) List and 305(b) Report]

Impairment Types

Impairment Maps

Biological Restoration Initiative

Local TMDL Implementation Guidance

Nonpoint Source Program (319) Management and Financial Assistance

Water Quality Financing

Chesapeake & Atlantic Coastal Bays Trust Fund (leaving MDE website)


What's New?

Maryland Water Quality Trading Advisory Committee (WQTAC) formed to provide direction to the overall trading program and to oversee further enhancement of the trading infrastructure

Maryland submitted its revised BMP verification protocols to the Chesapeake Bay Program Office (CBPO) on January 6, 2016.

Alliance for the Chesapeake Bay “Reduce your Stormwater” website (leaving MDE) is designed specifically to help homeowners and small businesses with stormwater related issues.

Maryland TMDL Data Center that includes a TMDL Search tool, TMDL Maps, a Waste Load Allocation (WLA) Search tool, and guidance to assist stormwater permittees develop implementation plans required by MS4 permits.

Homeowner SMART Stormwater BMP Reporting Tool is Being Pilot Tested (leaving MDE website)

Maryland's Interim BMP Reporting Tool is now available for use.  Please be sure to review submission instructions and additional information prior to using the new tool.

See What's New on Maryland's Implementing Maryland’s Action Plan - Building Local Partnerships webpage


TMDL implementation is a multi-disciplinary field involving planning and decision-making across different geographic scales and pollution source sectors for a variety of pollutants.  Although the Chesapeake Bay TMDL and accompanying Watershed Implementation Plan is currently a focus in Maryland, there are a variety of impairments and need for pollution controls.  This web page allows you to access information from a variety of perspectives.  We also encourage you to consult the websites of other States to gain a broader perspective.  (email Jim George MDE Science Services Administration).



The State of Maryland is committed to working toward the implementation of TMDLs.  MDE’s Science Services Administration (SSA formerly TARSA) is responsible for TMDL development, and plays a lead role in coordinating the implementation of TMDLs. However, the roles and responsibilities for specific TMDL implementation activities are distributed among a wide variety of private and public entities. Defining and communicating these roles and responsibilities is an on-going effort.

Federal Law and Regulation

The federal Clean Water Act, and implementing regulations (40CFR130 - leaving MDE website), say little about TMDL implementation. Briefly, TMDL regulations found at 40CFR130.7(a) specify that the State's Continuing Planning Process (CPP – 40CFR130.5) should describe how approved loads will be incorporated into NPDES permits and into the State's Water Quality Management Plans (40CFR130.6).

Federal Guidance

Federal EPA guidance on TMDL implementation is also limited. Guidance is provided in a 1997 EPA Memo entitled "New Policies for Establishing and Implementing Total Maximum Daily Loads (TMDLs)" (EPA Site, leaving MDE). On November 22, 2002, EPA provided clarification of existing TMDL regulations on the subject of implementing TMDLs through NPDES permits for stormwater. 

Impairment Types and Implementation Guidance

Waterbodies are considered impaired if they do not meet water quality standards. The following are types of pollutants that cause waterbodies to be impaired. Guidance to assist stormwater permittees and other jurisdictions in their planning efforts is available on MDE's website.



Other Guidance


Watershed Implementation Plans

Examples of Marylands's EPA-accepted nine-element watershed plans for various impairments can be found on MDE’s 319(h) Grant Program web page.


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Chesapeake Bay TMDL Implementation and Guidance

In 2012 Maryland developed its Phase II "Watershed Implementation Plan" (WIP) for the Chesapeake Bay nutrient and sediment TMDLs. Maryland’s Phase II Plan provides a set of proposed strategies for reducing pollution from waste water, septic systems, urban stormwater, and agriculture sectors. With 2009 as a baseline, the goals are to achieve 60% of the pollutant reductions by 2017 and full reductions by 2025.

Local partners across the State play a critical role in taking actions to restore their local waterbodies, which in turn controls pollution going to the Chesapeake Bay. State partners regularly engage local partners on a variety of technical and policy issues. The webpage, "Implementing Maryland's Action Plan," supports this on-going process.

2-Year Milestone Commitments, adopted both by the State and local partners, play a key role by establishing transparent, near-term goals:

Bay TMDL Implementation Progress Status

EPA has more general information on their Chesapeake Bay TMDL (leaving MDE) webpage.

Biological Restoration Initiative

Most of the biological impairments on Maryland’s 303(d) list are due to the degradation of small, fairly shallow, free-flowing streams. MDE has initiated a Biological Restoration Initiative (BRI) to target resources to streams with the greatest recovery potential.  This restoration initiative, a part of Maryland’s 319 Nonpoint Source Program, is coordinated with Maryland’s Chesapeake and Atlantic Bays Trust Fund (leaving MDE) through the Fund’s system of targeting resources [PDF] (leaving MDE).

Maryland’s Biological Restoration Initiative works in concert with the State’s anti-degradation policy implementation designed to protect high quality streams. These streams are identified using the Department of Natural Resources Maryland Biological Stream Survey (MBSS) Program (Leaving MDE) data. These high quality streams receive additional scrutiny to ensure that their biological integrity is protected.

Biological restoration of streams is also conducted via agricultural conservation programs; local government programs, including the federal NPDES Stormwater permit program administered by MDE; and various other State and federal initiatives.


Factsheets and Key Resources


Contact Information

For information on TMDL Implementation contact Jim George at (410) 537-3579, MDE Science Services Administration.


Other Useful Links



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