Evaluate water quality impairments on forest and rangelands. This is calculated as the length of stream miles on forest or rangelands that are 303d listed for water quality impairments. Under the Clean Water Act the State Water Resource Control Board (SWRCB) and its Regional Boards establish water quality standards for California waterways. Every two years the Regional Water Quality Control Boards identify waterbodies (i.e. 303d list) that are impaired and not supporting beneficial uses.