Philadelphia Gas Works (PGW), overseen by the Pennsylvania Public Utility Commission, is the nation's largest municipally owned natural gas utility. It serves over 500,000 homes and businesses in the Philadelphia area. Founded in 1836, the company came under city ownership in 1987 and has been providing the majority of gas distributed within city limits. In 2014, the Philadelphia City Council refused to conduct hearings on a $1.86 billion sale of PGW, part of a two-year effort that was proposed by the mayor. The refusal led to the prospective buyer terminating its offer.
Is there an answer to this question (If it cannot be answered, say "unanswerable"): What is the largest city owned gas utility?
Philadelphia Gas Works