In January 2019, the company announced that it would accelerate retirement of its five coal-fired units, and focus on ""Columbia Gas" redirects here. NiSource's electric operations include power generation, transmission and local distribution, as well as wholesale and electric transmission transactions. Columbia Gas may also refer to Massachusetts gas line explosions and exit from MassachusettsMassachusetts gas line explosions and exit from MassachusettsTincher, Sarah (2 July 2015), “Columbia Pipeline Group completes spin-off from NiSource”, The State Journal, retrieved 2 September 2015.Tweh, Bowdeya (4 November 2011), "Report: NiSource among companies getting large tax breaks", In 2015, NiSource was named to the Dow Jones Sustainability—North America Index for the second year in a row and for the ninth time since 1999.NiSource operates seven local utilities in its service region: The company, based in Merrillville, Indiana, United States, has more than 8,000 employees. NiSource uses both traditional and renewable generation sources, including natural gas, hydroelectric, wind, and coal generated supplies, providing a total system operating net capability of more than 3,000 megawatts. NiSource Inc. is one of the largest fully regulated utility companies in the United States, serving approximately 3.5 million natural gas customers and 500,000 electric customers across seven states through its local Columbia Gas and NIPSCO brands. NiSource provides electric energy to nearly 500,000 customers, all located in northern Indiana. NiSource's natural gas utilities provide domestically produced supplies of natural gas to residential, commercial and industrial customers via nearly 60,000 miles of pipeline and related facilities in seven states: Indiana, Kentucky, Maryland, Massachusetts, Ohio, Pennsylvania and Virginia.