1972 - Congress enacts the Federal Water Pollution Control Act, commonly known as the Clean Water Act (CWA)
- Required states to develop water quality criteria
- Required states to monitor waterbodies within their boundaries for compliance
- Required states to report non-compliant waterbodies to the US Environmental Protection Agency (USEPA)
- 303(d) Impaired Waters List cites the specific portion of the waterbody and specific unmet water critieria
There was a significant delay from 1972 prior to states actually developoing 303(d) Impaired Water Lists - the first list was produced in 1994. Virginia produced its first list in 1996. Impaired water lists are prepared by the states for the USEPA biennially on even-numbered years.