Penn Township commissioners voted Monday to relax proposed setback requirements for Marcellus Shale gas drilling, reversing an earlier decision to increase them by hundreds of feet.

Reverting to their initial proposal, commissioners plan to ban hydraulic fracturing operations within a 600-foot buffer zone around homes, schools and businesses on properties encompassing less than a certain acreage. At a work session last week, they agreed to expand that zone to 1,000 feet, citing a desire to increase protections for landowners near proposed drilling sites.

The reason for the reversal amounted to a misunderstanding, township manager Alex Graziani said, with last week’s decision proposing that the setback start at property lines, rather than buildings themselves. That, he said, was not made clear in the discussion that preceded the vote.

Among the several dozen attendees at Monday’s meeting were township landowners who have signed leases with gas drilling companies. Commissioner Jeff Shula abstained from voting because he has leased his property to the Monroeville-based gas drilling company Huntley & Huntley, whose land acquisition arm last year purchased about 220 acres off Pleasant Valley Road, near Murrysville.

The proposed setback requirements are a source of consternation for residents who have expressed concerns about environmental and health risks, along with fears of a possible decrease in property values if drilling takes place.

“I planned on living here for a long time,” resident Cheryl Kilroy said. But she added that she and her husband, who recently retired, have discussed moving if drilling occurs near their home. She noted that their drinking water comes from a well.

Ms. Kilroy is one of several dozen members of a citizens’ group that is urging commissioners to expand the buffer zone to 2,000 feet around buildings, citing research that suggests there could be health risks for those living in close proximity to fracking operations. The group, Protect PT, is planning to hire an environmental law firm, and it submitted about two dozen questions to commissioners about a month ago that Ms. Kilroy and others said remain unanswered.

The proposed setback requirements are part of a comprehensive revision of the township’s zoning laws, which also include a 1,000-foot buffer zone around water supply intakes. Commissioners are conducting a final review of the draft ordinance, which would not apply to rural areas and those zoned for agricultural and industrial use but would require that drilling companies apply for a conditional use permit before tapping unconventional wells.

But they carry significance beyond township boundaries.

In neighboring Trafford, some residents in a subdivision are concerned about plans by a drilling company to begin operations on nearby farmland in Penn Township. The site, in the Level Green area, is less than 2,000 feet from the subdivision, which comprises dozens of homes.

The drilling company, Apex Energy LLC, has received approval from the state Department of Environmental Protection to begin operations there and at another site, near Monroeville. The Wexford-based company also has submitted an application for a nearly 90-acre site near Delmont, near the senior living facility William Penn Care Center, and it is seeking more permits.

They are the only two sites in Penn Township for which the state has recently issued drilling permits, according to DEP records. The township has said it will issue no conditional use permits before it adopts the proposed zoning changes, which could come as early as April, Mr. Graziani said.

At a public meeting early next month on the draft ordinance, Trafford Mayor Ray Peduzzi is expected to address township leaders, intending to request that they expand the buffer zone while relaying concerns expressed by borough residents. The Feb. 5 meeting is scheduled for 6:30 p.m. in the Penn Middle School auditorium.

“Anything over what it is now is better,” Gillian Graber, who was recently appointed president of Protect PT, said of the proposed 600-foot buffer zone. A mother of two who moved with her husband to a Trafford neighborhood last year, she said she worries not only about any disturbances from trucks hauling away wastewater from fracking operations, but also about the possibility of accidents. “There’s a lot at stake here.”

First Published: January 22, 2015, 5:00 a.m.