PHMSA’s expansive Natural Gas Notice of Proposed Rulemaking will be published in the Federal Register tomorrow, April 8, 2016.  The Agency released a pre-publication version of its proposed rulemaking several weeks ago, but note that the Federal Register pre-publication version of what will be officially published tomorrow contains slight non-substantive differences from the Agency’s prior released version (e.g., capitalizations, movement of certain proposed revisions among subsections, etc.).  The proposal significantly expands numerous requirements for gas transmission and gathering pipelines.  Publication in the Federal Register triggers the start of the comment period, with comments due on or before June 7, 2016, unless an extension is granted.  Due to the complexity and volume of the proposed changes, several industry trade groups already have requests pending for a 60 day extension of the comment deadline.