The Clean Air Act of 1970 and its subsequent amendments in 1990 and 1997 mandated permit requirements and specific 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, mandating covered facilities to either obtain individual permits, participate in a group, or seek coverage under an Epa general permit.