Section 303(d) of the Federal Clean Water Act and the United States Environmental Protection Agency's (USEPA) Water Quality Planning and Management Regulations (40 CFR Part 130), requires:
- States identify water bodies in violation of the water quality standards for any given pollutant
- States develop a Total Maximum Daily Load (TMDL) determining the maximum amount of pollutant that a water body is capable of receiving while continuing to meet the existing water quality standards
TMDLs provide the framework that allows states to establish water quality controls reducing sources of pollution with the ultimate goal of water quality restoration and the maintenance of water resources.
Four Mile Run was on the Virginia 303(d) Impaired Waters List in:
The completion of the TMDL for the nontidal portion of Four Mile Run in May 2002 marked the first urban nonpoint source TMDL for Virginia and one of the first in the country.