PHILADELPHIA (CBS/AP) — A regulatory agency that’s responsible for the water supply of more than 13 million people in four states voted Thursday to permanently ban natural gas drilling and fracking in the watershed. The Delaware River Basin Commission imposed what it said was a temporary moratorium on gas development more than a decade ago, citing the need to develop environmental regulations for the industry, before reversing course in 2017 and signaling it would enact a permanent ban.

The ban applies to two counties in Pennsylvania’s northeastern tip that are part of the nation’s largest gas field, the Marcellus Shale. Nearly 13,000 wells have been drilled elsewhere in the vast Marcellus formation, turning Pennsylvania into the nation’s No. 2 gas-producing state.

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Republican state lawmakers in Pennsylvania as well as a landowners group have filed lawsuits challenging the commission’s right to regulate gas development in the watershed.

The Pennsylvania Chamber of Business and Industry said they were “extremely disappointed” in the ban.

“Throughout the pandemic, we have been told by government leaders to trust the science. The science is clear: as both the EPA and other water quality regulators, including the Susquehanna River Basin Commission, have noted, there is no support to any claim that drilling results in widespread impacts to drinking water, rivers or groundwater. This was a political decision uninformed by science,” said Gene Barr, president and CEO of the Pennsylvania Chamber of Business and Industry.

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Farmers and other landowners who had once leased their land to drilling companies have bitterly opposed the moratorium. Drilling opponents, meanwhile, have long contended that large-scale gas exploration could not be done safely so close to crucial waterways and renowned fisheries.

The commissioners agreed, saying Thursday that fracking poses too great of a risk to the water supply. The Delaware and its tributaries supply drinking water to Philadelphia and half the population of New York City.

Conservation officials once estimated that gas companies had more than 300 square miles of watershed land under lease. The drillers have long since pulled up stakes amid the longstanding moratorium.

Energy companies combine horizontal drilling with hydraulic fracturing, or “fracking,” a technique that injects vast amounts of water, along with sand and chemicals, underground to break up the shale and release the gas.

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