By a 14-1 vote, the Environmental Quality Board passed a proposal to update regulations that govern well construction and water use so they also address deeper and higher pressure drilling on the vast Marcellus Shale reserve. The Independent Regulatory Review Commission and legislative committees still need to approve the proposal.

"In many ways, these rules are long overdue because they are addressing problems we experienced even before the first Marcellus well got here," said John Hanger, who heads the Department of Environmental Protection.

Hanger's agency wrote the proposed new regulations, which were supported by an industry group, the Canonsburg-based Marcellus Shale Coalition. Many of the board members are appointees by Gov. Ed Rendell, and the House Republican representative cast the lone "no" vote.

Before the Marcellus Shale boom began roughly two years ago, Pennsylvania's gas industry historically had drilled lower-pressure wells into shallow sand formations.

The new rules will apply to both types of drilling and should make future problems with gas migration less likely, if followed and enforced, Hanger said. He did not want to say whether he thought the rules would have prevented any current problems, such as those in the northeastern Pennsylvania town of Dimock.

The regulations would lower the maximum allowable well pressures, raise standards for well cement and pipes, and require drilling companies to restore water supplies they pollute. They also would require drilling companies to report waste volumes electronically and to report the chemicals used in each well.

Extracting gas from the shale involves a technique called hydraulic fracturing in which crews pump millions of gallons of chemical-laced water and sand deep into the earth to splinter the dense shale and free the gas trapped inside.

Some of the water returns as a briny, chemical- and metal-laden brew and often is stored in open pits until it's trucked to treatment plants or underground injection wells.

The oil and gas industry steadfastly defends hydraulic fracturing as having been proven safe over many years and says it is a crucial tool if the country is going to be able to harvest its gas reserves. Many companies that make the chemical additives that are injected underground have been unwilling to publicly disclose the formulas.

A preliminary study by researchers with the Academy of Natural Sciences asserts the drilling boom could put rivers and streams at risk of pollution, even without spills or accidents.