Chesapeake Bay TMDL

By definition, a Total Maximum Daily Load (TMDL) is an estimate of the maximum amount of an impairing substance or stressor (pollutant) that a waterbody can assimilate without violating water quality standards. The total load includes pollutants from pipes, called point sources, and stormwater runoff and groundwater flow called non-point sources. A "margin of safety" is also included in the total load to account for the uncertainties. Additional information can be found at

Why should Anne Arundel County be Concerned About TMDLs?

Based on the federal government’s Clean Water Act, all states are required to consider the development of TMDLs for waterbodies that do not meet water quality standards for various pollutants. All of the twelve major waterbodies in Anne Arundel County are impaired by two or more substances (e.g., nutrients, sediments, fecal coliform bacteria, toxics, biological, or metals). The Watershed Assessment and Planning program is continuously monitoring the state of TMDL development and water quality analyses to justify the delisting of waterbodies from the MDE 303(d) impairment list.


Draft TMDL Restoration Plans

Approved TMDL Restoration Plans

Progress Reports

Below are Programmatic and Implementation progress reports as required by the Maryland Department of the Environment. Programmatic Milestones are commitments to non-project improvements such as organizational, process, and capacity building changes that position Anne Arundel County to implement it's WIP. Implementation Milestones are commitments to on-the-ground activities that result in nutrient and sediment load reductions.


Programmatic Milestones - Progress Reports

Implementation Milestones - Progress Reports