Proposed settlement would allow drilling to resume on Mariner East pipelines

State regulators, Sunoco Pipeline and environmental groups have reached a settlement agreement to allow underground boring to resume on the Mariner East 2 cross-state natural gas liquids pipeline with conditions meant to protect against the kinds of spills that have bedeviled the construction project so far.

The proposed settlement filed Tuesday evening calls for Sunoco to re-evaluate higher-risk sites where it plans to perform horizontal directional drilling or where lubricating muds migrated through cracks to the ground or water during drilling for the project.

A Pennsylvania Environmental Hearing Board judge halted directional drilling for Sunoco’s twin pipelines on July 25 until he could hold a hearing to evaluate environmental groups’ challenge to the construction permits. Some of the restrictions were lifted last week.

On Tuesday evening, Judge Bernard Labuskes Jr. postponed the hearing and extended the remaining drilling suspension until he can review the proposed settlement. The hearing had previously been scheduled for Wednesday morning. He did not indicate when he will rule on the proposal. 

The pipeline project released a clay slurry made of bentonite and water roughly 90 times over a three-month period during horizontal directional drilling, a construction practice used to tunnel under roadways, rivers and areas of dense development. The releases clouded more than a dozen private water supplies, seeped through bedrock and muddied wetlands and lakes.

In the proposed settlement, Sunoco agrees to review 47 boring sites based on their proximity to drinking water supplies, valuable natural features and utility lines, as well as their depth and geological setting, among other factors. The company will reassess sites of past spills where a second pipeline will be installed in the same right-of-way.

The reviews will include a re-examination of the geology at each site to see whether it is suitable for drilling and whether open trenches, drilling adaptations or other routes might be safer. Sunoco will produce a report for Department of Environmental Protection approval after each assessment specifying the steps the company will take to eliminate or control the release of drilling fluids there. The reports will be posted online.

Under the terms of the proposed settlement, residents who have water supplies near the relevant drilling sites will be given time to review and comment on proposed changes if the recommendations involve modifying Sunoco’s existing permits.

Before starting or resuming drilling, Sunoco will have to notify landowners within 450 feet of the drilling path and offer to sample their water supplies before, during and after drilling. The company also will have to immediately notify residents when it or DEP determines there is “a substantial possibility” that the drilling operations will affect their water supply.

The appeal was brought by the Clean Air Council, the Delaware Riverkeeper Network and the Mountain Watershed Association.

Sunoco Pipeline is a subsidiary of Texas-based Energy Transfer Partners. The twin 350-mile-long pipelines are expected to carry an initial combined capacity of 500,000 barrels per day of propane, butane and ethane from the Marcellus and Utica shales to terminals near Philadelphia.

Laura Legere:

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