Drought and sea level rise are causing salty oceanwater to creep into the Delaware River, threatening a source of drinking water for Philadelphia and millions of other people.

A regulatory agency responsible for the water supply of more than 13 million people in four Northeastern states says it is banning gas drillers from dumping fracking wastewater in its watershed.

Hundreds have gathered on both sides of the Delaware River to watch an annual Christmas Day reenactment of George Washington’s 1776 crossing.

A regulatory agency that’s responsible for the water supply of more than 13 million people in four Northeastern states voted Thursday to permanently ban natural gas drilling and fracking near a crucial waterway, asserting that gas development poses an unacceptable risk. Ad“The fracking ban in the Delaware River Basin is a momentous victory for public health, the environment, and against climate change,” said Kimberly Ong, an attorney at the Natural Resources Defense Council. Industry officials pointed to studies by a neighboring regulatory agency, the Susquehanna River Basin Commission, that found no link between intensive gas drilling in the Marcellus and degradation of the watershed. The drilling methods spurred a U.S. production boom in shale gas and oil. Conservation officials once estimated that gas companies had leased more than 300 square miles of Delaware River watershed land.