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
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.
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.
Hydrologic Group A
Hydrologic Group B
Hydrologic Group C
Hydrologic Group D
Hydrologic Group E