A study of methane emissions from heavy duty natural gas-powered vehicles and refueling stations by West Virginia University scientists at the Center for Alternative Fuels, Engines and Emissions, recently published by Environmental Science & Technology, greatly expands on very limited data on methane emissions from natural gas-fueled vehicles. The WVU pump-to-wheels study is the first end-use paper in a collaborative scientific research series designed to measure and better understand the sources and amount of greenhouse-gas methane that is emitted across the natural gas supply chain.