More than a year after the state Commonwealth Court denied a third appeal of a Middlesex Township zoning ordinance allowing shale development in residential-agricultural districts, the state Supreme Court last week ordered a new appeal to proceed.

The move comes four years after the township’s zoning hearing board began discussing the ordinance. It was later approved by township supervisors, and was subsequently appealed by critics.

The appeal, filed by the Clean Air Council, Delaware Riverkeeper Network and three township residents who live near the Geyer gas wells on Denny Road, argued that shale gas development is an industrial use that does not belong in the township’s residential-agricultural zone.

The appellants also argued that the pollution and potential danger associated with shale gas drilling is unacceptable near Mars schools and the Weatherburn Heights housing development, which are within a mile of the Geyer well pad.

Rex Energy, which operated the wells, and the township argued that shale gas development is not an industrial use because the earth-moving, lights, noise and traffic involved are temporary. They also asserted that shale gas development helps to preserve agricultural areas because it precludes housing developments.

After several hearings, the zoning board upheld the amendment. The objectors then appealed in Butler County Common Pleas Court, where they were also denied.

In 2016, witnesses for both sides testified during an appeal in state Commonwealth Court in Pittsburgh, where a panel of judges denied that appeal in June 2017. At the time, attorneys said an appeal to the state Supreme Court was likely. Had that appeal been denied, the matter would have ended.

However, in its Aug. 3 ruling the justices granted a petition to allow a new appeal. The ruling also vacated the Commonwealth Court’s 2017 order.

The new order highlights a state Supreme Court decision from June, in the case of Gorsline v. Board of Supervisors of Fairfield Township. In that case, justices ruled that a natural gas company could drill in a residential-agricultural district in Lycoming County.

The case involved a 59-acre piece of property owned by two Fairfield Township residents. The township’s zoning law did not specifically permit gas drilling, but supervisors voted to issue a conditional use permit for the project.

The Lycoming County Court of Common Pleas reversed that decision, and an appeal was then made to the Commonwealth Court, which overturned the county court’s decision. That led to an appeal by the property owners, and ultimately a 4-3 vote by the state Supreme Court on June 1, to limit where gas developers can operate.

According to court documents, justices found the township ordinance does not explicitly state such drilling operations are permitted in the district, making the conditional use tag unavailable.

The Supreme Court found the Commonwealth Court cited no evidence or explanation in overturning the Common Pleas Court ruling, and misinterpreted what the term “public service facility” is intended to define.

Justices, however, noted, “this decision should not be misconstrued as an indication that oil and gas development is never permitted in residential/agricultural districts, or that it is fundamentally incompatible with residential or agricultural uses.”

In its Aug. 3 ruling on the Middlesex issue, the court asked the Commonwealth Court to reconsider the relevance of the Lycoming County case in its analysis. It also asks for consideration of a ruling in a case involving the Pennsylvania Environmental Defense Foundation, which outlines the criteria for granting permits.

Michael Gallagher, who represents the Middlesex zoning hearing board, said the Commonwealth Court will likely next decide whether to use existing information to reconsider the case or whether new arguments will be heard.

He added Rex Energy’s bankruptcy filing, which came in May, presents a curious wrinkle, as such proceedings typically come with an automatic stay for any litigation.

Rex Energy officials could not be reached for comment Tuesday.