In April 2016, the U.S. Department of Transportation's Pipeline and Hazardous Materials Safety Administration ("PHMSA") published a long-anticipated rulemaking proposal for gas gathering and transmission lines. More than four years in the making, the proposed rules would significantly expand PHMSA's jurisdiction over gas gathering lines and add several new requirements to the agency's regulations for gas transmission lines. Many of these proposals respond to congressional mandates and recommendations issued by...