Pennsylvania regulators have fined Sunoco Pipeline LP for violations that occurred over the last two years during construction of the Mariner East (ME) 2 pipeline, this time issuing two penalties for more than $300,000.

The state Department of Environmental Protection (DEP) issued the penalties for violations of the Clean Streams Law and Dam Safety and Encroachment Act during construction in 10 counties.

The ME system, which consists of three pipelines in various stages of development and service, has faced constant regulatory and legal challenges that have led to delays and operational problems. The system moves natural gas liquids (NGL) from processing facilities in Ohio, Pennsylvania and West Virginia to the Marcus Hook Industrial Complex near Philadelphia.

DEP’s latest penalties bring the total for the project to more than 80 violations at a cost of more than $13 million. Construction started on ME 2 in 2017, followed by construction on ME 2X. ME 1, an old refined products line, was converted in 2013 to move NGLs and has faced service outages for months at a time in recent years due to sinkholes that have formed along the route.

Most recently, DEP fined Energy Transfer LP subsidiary Sunoco $240,840 for horizontal drilling activities last year that resulted in unauthorized discharges of drilling fluids, or inadvertent returns, to surface waters. Drilling operations have been halted in the past in response to an abnormal amount of returns.

The agency also issued a fine of $78,621 for work that accelerated erosion and sedimentation at various sites in Cumberland County. Specifically, DEP said Sunoco failed to minimize erosion and sedimentation, didn’t properly stabilize areas after earth disturbance activities and violated its permits, among other things.

Sunoco has agreed to pay both fines.

ME 2 entered partial service late last year using a short stretch of 12-inch diameter pipeline that once carried refined products to bypass areas where construction was suspended because of regulatory issues. The project also has faced resistance from some communities and lawmakers along the route.

Project penalties culminated last year in a historic $12.6 million fine to resolve dozens of violations related to ME 2 construction. Work on ME 2X also continues.