Philadelphia water contamination from Delaware River spill: Safety, chemicals, what we know

The city of Philadelphia sent its 1.5 million residents into a mad dash for bottled water after issuing — and retracting — a tap water advisory on Sunday afternoon.

The cause: a chemical spill from a Bucks County plant into a Delaware River tributary that feeds into a Philadelphia water processing facility. The city said Tuesday evening that Philadelphia's tap water remained safe and the threat of potential contamination had passed.

Here's what we know and don't know about the spill and Philly's water.

Yes.

Yes. City officials announced Tuesday that Philadelphia's drinking water will not be impacted by the spill in Bristol. Testing of water at the Baxter Water Treatment Plant, which serves the part of the city east of the Schuykill, did not at any point detect any chemicals from the spill in the city's water supply.

"We can all confidently say the threat has passed," Mayor Jim Kenney said. "I repeat, all the city's drinking water is safe to drink."

Models tracking the flow and tide of the Delaware River have shown that the threat of potential contamination has passed the city, Kenney added. As a result, the city's water "will not be impacted by the spill."

The spill occurred at a Trinseo plant in Bristol, Bucks County, on Friday, when the company said "an equipment failure" dumped about 8,100 gallons of latex emulsion solution into Otter Creek, a tributary of the Delaware River.

Latex emulsion solution is about 50% water and 50% percent latex polymer, per Trinseo, but it also contains butyl acrylate, one of the chemicals released in the East Palestine, Ohio, train derailment.

Trinseo's statement said the chemical mixture "overflowed the on-site containment system and entered a storm drain, where it flowed to Otter Creek and then to the Delaware River."

The company is conducting a review of vulnerabilities in their latex processing system and plans to resume partial production within the next few days, per a statement from Trinseo.

Philadelphia closed the Baxter Water Treatment facility on Friday following the spill, but reopened it on Sunday to maintain minimum water levels. Since then, the city performed roughly 40 tests on water from the Delaware River and the Baxter plant, but did not detect chemicals from the spill as of Tuesday, when the city gave the all-clear on any potential contamination.

"There was never any detection in Philadelphia," Mike Carroll, deputy managing director for the city, said.

Carroll said earlier in the week that the Pennsylvania Department of Environmental Protection and Philadelphia police did a flyover of the Delaware River and "saw no visual evidence of any plumes" from the spill.

All Philadelphia neighborhoods east of the Schuylkill could have been impacted, per a map released by the city on Sunday afternoon. The areas of the city that would not have been impacted by the chemical spill include Southwest and West Philly, plus parts of Northwest Philly, like Roxborough and Chestnut Hill.

Across the Delaware, New Jersey American Water asked Camden, Burlington, and Gloucester counties to limit water usage as a result of the spill, even though it likely did not impact treated drinking water at the area's Delaware River Regional Water Treatment Plant. The company lifted that advisory on Tuesday afternoon.

Over in Bucks County, officials said the region's water providers — Pennsylvania American Water, Aqua, and the Lower Bucks Joint Municipal Authority — all advised that "there are currently no known adverse impacts to drinking water."

» READ MORE: Where Philly's drinking water comes from

The spill released three main chemicals: ethyl acrylate, methyl methacrylate, and butyl acrylate.

Carroll, the OIT spokesperson, said the risks associated with them are "very low," and that people who ingest water should "not suffer any near-term symptoms or any acute medical conditions."

Boiling the tap water won't remove the chemicals, but you can still bathe or wash dishes with the potentially contaminated water.

» READ MORE: What we know about the chemicals raising concern about Philly's drinking water

Ethyl acrylate: This is used in paints and plastics, and there is some weak evidence that it can cause cancer. Acute exposure can cause headaches, drowsiness, and nausea.

Methyl methacrylate: This resin is commonly used as cement in dentistry and orthopedic surgery. It's not considered a carcinogen.

Butyl acrylate: If inhaled in large quantities, this flammable chemical can cause respiratory issues. It can also cause irritation if it comes in contact with eyes or skin.

Long-term side effects of ingesting these chemicals — especially via water, are unknown, according to Keeve Nachman, associate professor of environmental health and engineering at Johns Hopkins University.

Still, "people need to drink water [that is contaminated] at fairly high levels for a long time before we anticipate any potential negative health effects," he said.

Ingesting trace amounts of these chemicals also won't induce a reaction in people with latex allergies, said Jonathan Spergel, chief of the allergy program at Children's Hospital of Philadelphia. The allergy comes from latex's rubber element, which you can only find on certain trees.

Trinseo is a plastic manufacturer formerly owned by Dow Chemical and the European Plexiglass purveyor Altuglas International.

Trinseo specializes in "latex binders," which are a versatile mixture of chemicals: Latex binders make cement malleable, create waterproof coatings, and help make things like textiles and medical machinery sturdy.

At least four times, technically.

Before Trinseo acquired the Bristol plant in late 2021, the sprawling chemical plant was operated by Arkema, a European chemical conglomerate.

Under Arkema's ownership, the Bucks County latex binder plant leaked chemicals in the surrounding environment on at least four separate occasions.

The first: The U.S. Environmental Protection Agency discovered Arkema released 1,760 pounds of methyl methacrylate during a storage tank transfer in 2010. The EPA documented another leak at the Bristol plant between 2012 and 2013, this time releasing butyl acrylate and ethyl acrylate. U.S. Coast Guard National Response Center records indicate the same plant spilled 300 gallons of ethyl acrylate in 2014, triggering a shelter-in-place order for a local school, a facility evaluation, and the removal of contaminated soil and asphalt. Finally, the Coast Guard identified an Arkema pipeline at the facility as the source of a second methyl methacrylate leak in early 2020. In between, the EPA issued a corrective action plan for the facility, finding groundwater there was "contaminated with a variety of organic and inorganic chemicals.

Since Trinseo took over, EPA records don't list any violations from the facility's acrylics section.

» READ MORE: Bristol plant that spilled chemicals had other mishaps over the past decade