Salt water creeping up Delaware River in worrying sign for big fresh water source

Source of Philadelphia's drinking water sees salt line pushed closer to city by drought and sea level rise

Salty ocean water is creeping up the Delaware River, the source for much of the drinking water for Philadelphia and millions of others, brought on by drought conditions and sea level rise, and prompting officials to tap reservoirs to push the un-potable tide back downstream.

Officials say drinking water is not imminently at risk, but they are monitoring the effects of the drought on the river and studying options for the future in case further droughts sap the area, amid the climate crisis.