Philadelphia officials closely monitor drinking water after a chemical spill in the Delaware River

Philadelphia officials are monitoring the city’s drinking water system carefully following a chemical spill just a few miles upstream of a key tap water intake in the Delaware River, saying the water would be safe to drink until at least 11:59 p.m. on Monday.

“The water that is currently available to customers was treated before the spill reached Philadelphia and remains safe to drink and use for bathing, cooking and washing,” the city said Sunday in a statement.

None of the three chemicals that leaked into the river when a latex product...