PA DEP Issues Permit for Expansion of MarkWest Harmon Creek Plant
The Pennsylvania Department of Environmental Protection issued an air quality permit on May 18, 2026, to MarkWest Liberty Midstream, authorizing the expansion of its Harmon Creek Natural Gas Processing Plant in Washington County. The MarkWest name is still used, although the company is now MPLX. The DEP permit approval allows the addition of a third cryogenic plant and a second de-ethanization plant. A number of Big Green groups colluded in an attempt to block the permits, but their demands were ignored.To view this content, log into your member account. (Not a member? Join Today!)