FERC has issued a favorable environmental assessment (EA) of Columbia Gas Transmission LLC’s (TCO) Tri-County Replacement Project in Southwest Pennsylvania, which is part of a broader modernization program to replace aging segments of the 12,000-mile natural gas pipeline system.

“The proposed project, with appropriate mitigating measures, would not constitute a major federal action significantly affecting the quality of the human environment,” Federal Energy Regulatory Commission staff said in the EA.

TCO wants authorization to spend about $138 million to replace 34 miles of bare steel pipe within its Line 1570 pipeline that spans Allegheny, Washington and Greene counties. About 14 miles of the outdated steel pipe would be replaced in Greene County and 20 miles would be replaced in Washington and Allegheny counties. Bidirectional pig launchers and receivers would be installed along with main line valves, taps and other equipment.

The proposed project part of a broader overhaul that began in July when TCO parent Columbia Pipeline Group (CPGX) split from NiSource Inc. CPGX has billions of dollars of investments planned in the Appalachian Basin for midstream expansions (see Daily GPI, May 14). Net investments in pipeline, storage and midstream assets are expected to reach $13.5 billion by the end of 2020.

The bare steel pipes being replaced on Line 1570 were installed through the 1970s, but they don’t meet today’s standards for corrosion-resistant materials. FERC has sent copies of the EA to stakeholders for a public comment period that ends Oct. 14.