W. Va. Code § 22A-2A-401: General provisions relating to requirements for exhaust emissions.

This part is intended to control the potential health hazards of diesel exhaust by requiring that diesel-powered machines be equipped with clean-burning engines, that exhaust emissions control and conditioning systems may be required on diesel engines as specified by the commission, that exhaust emissions be monitored and controlled and that standards be established for the allowable concentrations of exhaust emissions in a mine environment.