Section 10d of the Motor Fuels Quality Act limits the vapor pressure (evaporative tendencies) of the gasoline sold or dispensed in Lenawee, Livingston, Macomb, Monroe, Oakland, St. Clair, Washtenaw and Wayne counties from June 1st through September 15th each year to not more than 7.0 pounds per square inch (MCL 290.650d). If your firm dispenses or delivers gasoline in the control area, you should review this requirement prior to June 1st and monitor your inventory turnover to ensure you are dispensing or delivering compliant fuel on or before June 1st.
Gasoline stations in the eight County, Southeast Michigan areas must sell only the summer formula gasoline and meet other federal requirements. The gasoline must be formulated to be 7.0 pounds per square inch (psi) of pressure under the Reid Vapor Pressure (RVP) system, which is lower than normal gasoline psi, to reduce the likelihood of evaporation that, in turn, contributes to ozone build-up. Gasoline that contains 9-10% ethanol, by volume, is allowed a one (1) psi vapor pressure waiver under Michigan Regulation 561 (R285.561.8).
All phases of the gasoline distribution system, including refineries, importers, pipelines, terminals and filing stations, must meet the 7.0 psi requirements June 1 through September 15. Wholesale locations with bulk storage must begin the process sooner to allow total inventory turnover at retail gasoline stations on or before June 1.
Additional information may be obtained by contacting the Motor Fuels Quality Program at (517) 655-8202. Public Act 44 of 1984, Motor Fuels Quality Act may be referenced at http://www.legislature.mi.gov. Regulation 561 may be referenced at http://www.michigan.gov/mdard/0,4610,7-125–272309–.00.html