Total Maximum Daily Load (TMDL)

​What is a TMDL?

A Total Maximum Daily Load is a plan of action used to clean up streams that are not meeting water quality standards. The plan includes pollution source identification and strategy development for contaminant source reduction or elimination.

How It Works

Teams of environmental specialists travel throughout West Virginia's watersheds, sampling streams and determining their level of impairment. After a stream is considered impaired and put on the 303(d) list, a TMDL is developed for the stream. The state is divided into 32 major watersheds, which are placed into one of five hydrologic groups (hydrologic groups A - E). Each year, DEP personnel select a watershed(s) from a predetermined hydrologic group to work in and begin the 4-year process of completing a TMDL. Currently, TMDLs are in various stages of development for certain watersheds in Hydrologic Group C, Hydrologic Group D, and Hydrologic Group E.

Why are TMDLs Necessary?

Public awareness and a desire to control water pollution led to passage of the federal Clean Water Act of 1972. The Clean Water Act established the basis for the regulation of discharging pollutants into streams. Pollution control programs greatly reduced the amount of pollutants that went into streams and navigable waters. Section 303(d) of the Clean Water Act and regulations developed by the U.S. Environmental Protection Agency (EPA), require states to identify all waters that do not meet water quality standards even after pollution controls required by law are in place. Waterbodies not meeting the appropriate water quality standards are considered to be impaired. The impaired segments identified by the states comprise each state's 303(d) list (or Section 303(d) list). The 303(d) list of impaired waters must be submitted to the EPA for review and approval. TMDL's must be developed for all waterbodies on the approved 303(d) list.

Completed TMDLs

West Virginia has worked diligently with the EPA and many other important stakeholders to assure the completion of TMDLs. Click on the watershed name below to see completed; TMDLs for that watershed. To receive a CD of West Virginia completed TMDLs, call (304) 926-0495.