Sunoco Pipeline LP’s Mariner East (ME) 2 natural gas pipeline project on Tuesday was ordered by the Pennsylvania Environmental Hearing Board (EHB) to halt all horizontal directional drilling (HDD) until Aug. 7, when environmental groups are scheduled to argue against the pipeline following a series of violations.

The Clean Air Council (CAC), Mountain Watershed Association and the Delaware Riverkeeper Network released documents from the state Department of Environmental Protection (DEP) on July 19 detailing more than 61 spills that had been reported by Sunoco during construction activities. On the same day, the groups filed an application asking for a temporary suspension of HDD operations as part of their appeal of the project’s permits, which were issued by the DEP earlier this year.

The EHB is a quasi-judicial body that hears appeals of final DEP actions, including challenges to permit decisions, enforcement actions and new regulations. “The relief is not permanent and the public must continue to call on elected officials and the DEP to defend the public interest by putting a long-term halt to the drilling, which Sunoco has been unable to do safely,” said CAC attorney Alex Bomstein.

Other construction on the project continues, including open-trench operations and conventional road boring, a company spokesman said. The EHB ordered active HDD to stop at 55 locations. The company has not begun drilling at another 168 locations.

“We believe that the full hearing before the EHB will demonstrate that we have expended every effort to meet the strict conditions of our environmental permits,” said Sunoco spokesman Jeffrey Shields. “We are continually evaluating our drilling plans and had already voluntarily suspended work on a number of our drills while working to ensure that the concerns outlined by the DEP and Gov. Tom Wolf were addressed. In the meantime, we will continue non-HDD construction throughout the state, with safety and protection of Pennsylvania’s environment as our first priorities.”

The DEP on Tuesday also stepped up its role in oversight of the project after issuing four notices of violation to Sunoco and executing a consent order and agreement (COA) last week. The COA carries with it a penalty of $87,600 for violating wetland regulations in an area adjacent to a highway in Cumberland County. The DEP said this week it would enforce the order and require corrective actions before the company may resume HDD operations. The violations are related to fluid releases during HDD.

“The corrective actions outlined in the COA are steps DEP is taking to hold Sunoco accountable and protect local residents,” DEP Secretary Patrick McDonnell said. “DEP is conducting its own independent investigation of this pollution event and reserves the right to assess further enforcement as appropriate.”

ME 2 battled landowners in courts across the state for years as it worked to secure some easements, and it has faced the ire of environmental groups opposed to fossil fuels. But the project began to attract more public attention earlier this month as construction moved toward Philadelphia. More than a dozen families in Chester County reported losing water pressure and murky water where HDD was underway. Local and state officials believe drilling mud — a mix of nontoxic bentonite clay and water — affected groundwater and private water wells in the area.

Sunoco was already working to pay for and connect the affected homes to municipal water supplies. Other landowners in the area have had discussions with the company about tapping public water. As part of its COA, the DEP is now requiring that Sunoco respond to any other homeowners whose wells were adversely impacted by HDD in the county. Both lawmakers and Gov. Tom Wolf have weighed in with concerns about project construction, as well.

The DEP order also requires Sunoco to have written authorization from the agency to resume HDD in the impacted area, and it has to submit a water supply restoration plan to the agency.

In related news, an administrative law judge this week temporarily suspended construction of a valve station for the project in West Goshen Township until the state Public Utility Commission (PUC) can determine if that work violated a township agreement. West Goshen officials have argued that the station should be built in a different location. The project has certificates of public convenience from the PUC.

The 350-mile pipeline would transport ethane, butane and propane from Ohio, Pennsylvania and West Virginia to the Marcus Hook Industrial Complex near Philadelphia for domestic and international distribution. Sunoco expects the project to be completed in two phases this year and next.