Fog systems when properly designed and applied can meet or exceed all air quality standards. The EPA now specifies fogging systems as Best Demonstrated Technology for Sub-bituminous coal.  In Wyoming, fogging systems are considered B.A.C.T. (Best Available Control Technology) for conveyors transporting PRB Coal, giving it a Zero Visible Emission Rating. At Rollover Rail Car Dumpers for PRB Coal, DSI has achieved reductions of over 96% as reported in Power Magazine .