PITTSBURGH - Switching fleet vehicles to four-cylinder models is just one part of a recommended strategy to help decrease the county government's overall carbon emissions, energy consumption, and water usage by 20 percent by 2015.

Allegheny County Executive Dan Onorato issued an executive order after announcing the results of the Allegheny County Greenhouse Gas Emissions Inventory Report and Climate Action Plan, a comprehensive baseline inventory of the annual greenhouse gas emissions resulting from County government operations.

The report gathered all cost and utilization data related to energy, water consumption, vehicle fleet, waste hauling, and a variety of additional carbon and greenhouse gas-generating items, such as fuel tanks, fire suppression systems, and mechanical equipment.

The study found Allegheny County government produced approximately 77,000 tons of carbon dioxide equivalent (eCO₂) emissions in 2008, the baseline year for the inventory. To meet the County Executive's goals, that baseline will have to be reduced by 20 percent, or 15,000 tons, and reach a level of 62,000 tons or less by 2015. The largest source of emissions (86 percent) comes from operating the County's 139 buildings and facilities. The remaining sources of emissions are vehicles, water delivery systems, wastewater treatment, solid waste management, streetlights, and other small fugitive sources.

Among the recommendations in the report is to limit vehicle purchases to four-cylinder vehicles (or vehicles with similar or better fuel efficiency) as the county's fleet is retired. By replacing 33 vehicles with four-cylinder models, Allegheny County expects to save more than 2,800 gallons of gasoline and 28 tons of CO₂ annually, the County stated on its Web site.

At gasoline costs of $3 per gallon, the move is expected to save the county $8,500 per year. The report also suggests replacing a portion of the county fleet with Zipcars and investing in hybrid vehicles.

The full report is available at www.alleghenycounty.us/alleghenygreen.