Biodiesel is a renewable fuel derived from vegetable oils or animal fats that can substitute for diesel fuel in engines or fuel oil in furnaces. Biodiesel has proven lubricity benefits at low blends and performs well as a substitute for petro-diesel. Blends of biodiesel reduce particulate matter (PM), volatile organic compounds (VOC), as well as other toxic gases and Greenhouse Gases (GHG). Reduced emissions from biodiesel blends result from its zero sulfur content and higher oxygen content versus petro-diesel. Federal standards established by the U.S. Environmental Protection Agency (EPA) have forced local authorities to implement policies to reduce VOC's, one of the precursors of ground level ozone formation, and other toxic emissions. The Twin Cities area has remained just below the EPA thresholds in recent years. In addition to VOC's, particulate matter (PM) from diesel engines poses additional health concerns, especially when originating from school buses, transit buses, and diesel-powered electrical generators. Minnesota statutes mandate the inclusion of 2% biodiesel for use in a majority of diesel-powered vehicles in the state starting in 2005. This study was undertaken to assist policy-makers who may suggest utilization of biodiesel blends as part of a strategy to reduce regional ground level ozone and particulate matter near certain emitting sources. Vehicles that may be prime targets for use of higher blends of biodiesel include school buses, transit buses, road equipment, diesel-powered electrical generators, and diesel "gensets" used for emergency and peak-shaving. A workbook model was developed to determine the amounts of 100% biodiesel (B100) needed to satisfy various blends for categories of machines in Minnesota, with special emphasis on the sources emitting the greatest amounts of pollutants in closest proximity to people. The workbook calculates the amounts of B100 needed in each county and month of the year for numerous scenarios. Such data should be helpful to fuel distributors as they determine how to supply vehicles and machines that may utilize biodiesel of various blends across the state.