The Algonquin natural gas pipeline runs under Mill Plain Road and the Still River. A recent study estimated that methane emissions from the distribution system range from about 393 gigagrams to 854 gigagrams per year — about 0.1 percent to 0.2 percent of the methane that is delivered nationwide. In either case, that is far lower than the EPA estimate of 1,329 gigagrams, which is based on the 1992 research.