Philadelphia officials on Sunday evening stepped back from a suggestion earlier in the day that residents consider using bottled water rather than tap water for drinking and cooking after a chemical leaked into a tributary of the Delaware River, a source of drinking water for about 14 million people across four states.
The previous advisory, issued on Sunday morning, came after a pipe ruptured at Trinseo PLC, a chemical plant, late on Friday, sending about 8,100 gallons of a water-soluble acrylic polymer solution into Otter Creek in Bucks County, north of Philadelphia, officials said.
Officials emphasized that contaminants had not been found in the city’s water system.
Officials said residents, out of an abundance of caution, could consider buying bottled water because, they said, it could not “be 100 percent sure that there won’t be traces of these chemicals in the tap water throughout the afternoon.”
At a news briefing later on Sunday, Michael Carroll, Philadelphia’s deputy managing director for transportation, infrastructure and sustainability, said such measures were unnecessary.
“If you want to store water, you should feel free to draw it from your tap, store it in a bottle, you can put in a pitcher, put it in your fridge,” he said. “There’s no need at this time for people to be rushing out and buying bottled water.”
Further, he said, the chance of contamination was diminishing over time. Flyovers by helicopter revealed no visual evidence of plumes in the river and tests revealed no levels of contamination near a water plant intake.
Nonetheless, the spill, coming more than a month after the catastrophic release of chemicals in a derailment in East Palestine, Ohio, appeared fresh on the minds of Philadelphia residents.
On a Facebook page featuring the earlier city news conference, commenters drew parallels to the Ohio derailment and sounded a reluctance to drink the municipal tap water.
Videos on social media showed a rush to buy bottled water and local television news also showed residents emptying grocery shelves of bottled water.
In an update on Sunday evening, Mr. Carroll said that tidal conditions and rain on Saturday should help the river “flush itself out” into the Delaware Bay.
“In a matter of days, the water in the Delaware should be OK,” Mr. Carroll added, emphasizing that the water in the tap — coming from water treatment facilities that were sampled for contamination earlier in the day — would be safe to drink until at least Monday evening.
After the spill, the city took in enough river water to supply its customers through 11:59 p.m. on Monday. Officials were confident that the supply was not contaminated. They planned to take in more water Sunday evening to reach customers’ taps by Tuesday — if testing proves that the fresh supply is safe.
The chemical leak appeared to result from an equipment failure, Trinseo said in a statement. Company representatives could not immediately be reached for further comment on Sunday.
“It’s like the material you find in paint,” Tim Thomas, a vice president at the Trinseo chemical plant, told WPVI-TV in Philadelphia. “It’s your typical acrylic paint you have in your house. That’s what really this material is, in a water base.”
Philadelphia’s water system serves about 2 million people in the city and surrounding counties, sourcing more than half of it from the Delaware River basin. The Delaware River also supplies water to Delaware, New Jersey and New York.
The Pennsylvania Department of Environmental Protection said as of Sunday morning, “no additional product was leaving the facility and entering the Delaware River.” Still, the U.S. Coast Guard, which also responded to the spill, said that people should avoid the site where cleanup operations were underway.
Two of the chemicals released through the burst pipe were butyl acrylate and ethyl acrylate, both colorless liquids with an acrid odor that are used for making paints, caulks and adhesives.
Both chemicals can cause breathing difficulties and irritation of the eyes and skin, according to the National Institute for Occupational Safety and Health. Butyl acrylate was among the hazardous materials aboard the Norfolk Southern train that derailed in Ohio.
Christopher Mele contributed reporting.