The Clean Air Act of 1970 and its subsequent amendments in 1990 and 1997 necessitated the implementation of permit requirements and limitations on point source emissions of volatile organic carbons, nitrogen oxides, sulfur dioxide and particulates. The Epa and designated state agencies have established regulations on discharges of storm water runoff and stationary sources of air emissions, which require covered facilities to obtain individual permits, participate in a group, or seek coverage under an Epa general permit.