By Valerie Volcovici and Nichola Groom WASHINGTON (Reuters) -Around 30 oil and gas facilities across the Permian Basin in Texas and New Mexico spewed large amounts of methane for three years, emitting the equivalent annual climate pollution from half a million cars, according to a report released on Monday. The facilities, which include well pads, pipelines, compressor stations and processing facilities, were observed as “persistently” emitting large volumes of methane over the three years of aerial surveys done by the Environmental Defense Fund and research group Carbon Mapper. Carbon Mapper …