Looking to cut greenhouse-gas emissions and reduce fuel costs in one blow, UPS Inc. will power two of its regional truck fleets with renewable natural gas (RNG) captured from decomposing landfills, the company said today.

Trucks from the Atlanta-based parcel carrier's fleet of renewable fuel vehicles in Memphis, Tenn., and Jackson, Miss., will burn the RNG instead of other alternative fuel designs in the UPS fleet, such as all-electric, hybrid electric, hydraulic hybrid, or propane.

UPS will purchase an estimated 15 million diesel-gallon equivalents of RNG as part of a multiyear agreement with Memphis Light, Gas and Water and with Atmos Energy Marketing LLC.

RNG, also known as biomethane, is derived from sources such as decomposing organic waste in landfills, wastewater treatment, or agriculture. Distributors then pipe it through existing natural-gas pipeline networks before using it as either liquefied natural gas (LNG) or compressed natural gas (CNG).

By capturing the methane gas emitted by decomposing landfills, UPS will gain a fuel source that powers trucks without creating greenhouse-gas pollution, and will also capture natural methane that would otherwise be released into the atmosphere as a greenhouse-gas emission, Mark Wallace, UPS senior vice president global engineering and sustainability, said in a statement.

UPS will use the RNG to power more than 140 heavy-duty trucks in Memphis and Jackson, part of the company's global natural-gas fleet of 3,800 medium- and heavy-duty vehicles. As part of its long-term sustainability efforts, the company has a goal of driving one billion miles with its alternative-fuels fleet—known as the Rolling Laboratory—by the end of 2017.