Sunoco Pipeline LP would pay a $200,000 fine and conduct a “remaining life study” to determine the forecasted retirement age of its 88-year-old Mariner East 1 pipeline to settle a complaint with state regulators stemming from a 2017 leak of natural gas liquids in Berks County.

The company, a subsidiary of Energy Transfer Partners, filed its proposed settlement Wednesday with Pennsylvania Public Utility Commission investigators. The deal requires approval of the PUC.

The PUC cited Sunoco last year for the April 2017 incident, in which 840 gallons, or 20 barrels, of gas liquids leaked from the pipeline along Route 10 near New Morgan Borough. The PUC cited Sunoco for inadequate cathodic protection of the pipeline that allowed it to corrode and to leak.

The eight-inch-diameter pipeline, built by Atlantic Refining in 1931 to deliver motor fuel and heating oil from its Philadelphia refinery to Western Pennsylvania, was acquired by Sunoco in 1988. Sunoco Pipeline in 2014 patched up and converted the pipeline, now renamed Mariner East, to carry natural gas liquids, such as propane and butane, from western Pennsylvania to Marcus Hook.

Sunoco is adding two more adjacent pipelines to the original Mariner East route, and has upgraded its Marcus Hook terminal to vastly increase capacity to transport gas liquids to market. But pipeline construction has disrupted communities, received numerous citations from state regulators, and is now the subject of a criminal investigation by local and state prosecutors.