Philadelphia and New York City could face significant challenges to their water supplies as drought conditions and rising sea levels push salty ocean water further up the Delaware River. This critical source of drinking water for over 14 million people, including residents in Pennsylvania, New Jersey and New York state, is now at risk following an extremely dry start to the fall season.
The salt line—the boundary where ocean saltwater and a river’s freshwater meet—has moved 20 miles north of its typical position near Wilmington, Delaware. It is now just south of the drinking water intakes for Philadelphia, around city’s airport. If conditions worsen, it could inch even closer, threatening the city’s water supply.
