Methane and Other Air Pollution Issues in Natural Gas Systems [Updated September 17, 2020] [open pdf - 1MB]
From the Summary: "This report provides information on the natural gas industry and the types and sources of air pollutants in the sector. It examines the role of the federal government in regulating these emissions, including the provisions in the Clean Air Act and other statutes, and EPA's and other agencies' regulatory activities. It concludes with a brief discussion of a number of issues under debate, including  defining the roles of industry and local, state, and federal governments;  establishing comprehensive emissions data;  determining the proper control of pollutants and sources;  understanding the human health and environmental impacts of emissions; and  estimating the costs of pollution abatement."
CRS Report for Congress, R42986
Congressional Research Service: https://crsreports.congress.gov/