The Pennsylvania Environmental Hearing Board (EHB) has denied the appeal of two environmental groups that have for years been challenging permits for six unconventional natural gas wells operated by Rex Energy Corp. near a school in Butler County.

The EHB, which reviews challenges brought against the Pennsylvania Department of Environmental Protection (DEP), found that the Delaware Riverkeeper Network, Clean Air Council and four residents failed to demonstrate that DEP acted unreasonably or violated statutes and regulations when it issued permits for the Geyer wells in 2014. The groups filed their appeal of the permits shortly after the permits were issued, along with a separate challenge of Middlesex Township’s decision to modify a zoning ordinance that allowed oil and gas development to occur within a mile of a school.

More important, the board found that DEP’s decision to issue the permits and renew them in 2015 did not violate Article I, Section 27, an environmental rights amendment in the state constitution that reads in part, “the people have a right to clean air, pure water and to the preservation of the natural scenic, historic and esthetic values of the environment.”

That aspect of the EHB’s ruling earlier this month further establishes a legal standard for how the amendment should be factored into energy development. Since a landmark state Supreme Court ruling in 2013, fossil fuel opponents have increasingly invoked the amendment to challenge unconventional gas development.

Last year, the state’s high court upheld the amendment in another ruling. But the justices tossed out a longstanding three-part test to determine when regulators have met their obligations under the environmental rights amendment as state trustees. Instead, the court ruled that an effective review “lies in the text of Article 1, Section 27 itself as well as the underlying principles of Pennsylvania trust law in effect at the time of its enactment.”

The EHB found that evidence and testimony in the Geyer case demonstrated that the DEP considered the environmental effects of its permit decision.

“Unlike other governmental entities who may not have the environment as a focus, the department’s mission makes consideration of environmental effects central to its responsibilities and it would be a surprise to us if department staff failed to do so when they make a permit decision,” the board said in its ruling. “The evidence presented by Delaware Riverkeeper does not convince us that the department failed to consider the potential for environmental effects in advance of issuing the Geyer well permits and renewal permits in this case.”

EHB also said its understanding of the environmental rights amendment does not require all permits to be denied if they pose a risk, which would otherwise “essentially prevent any permitting activity,” as the board said that it would be nearly impossible to allow industrial development without “some environmental impact.”

It’s unclear what comes next for the environmental groups. Both the zoning and permitting challenges brought attention when they were first filed years ago. Rex, which filed for bankruptcy last week for unrelated reasons, faced staunch opposition for its plans to drill near the Mars Area School District property, where thousands of students attend school.

Middlesex’s zoning board eventually rejected the appeal, but the groups pressed ahead with their case. It is currently pending in the state Supreme Court, where it’s on hold so the justices can hear a similar case from Lycoming County.

The cases, and others like them, pose a broader threat to the industry as they involve challenges against oil and gas development in residential-agricultural zones, where most drilling in the state occurs.