What is going on with Philadelphia’s drinking water?

City officials say it’s safe to drink following a chemical spill and previous recommendations to use bottled water.

This weekend, Philadelphia became the latest US city to navigate uncertainty about its drinking water following a chemical spill in the Delaware River from a nearby latex manufacturer. Currently, Philadelphia’s tap water will remain safe to drink through 11:59 pm local time on Wednesday, March 29, according to city officials, who’ve been conducting tests on the water supply. That’s a change from the message residents received midday on Sunday when a city text alert recommended that they use bottled water, spurring a rush to stores. Officials now say their goal is to provide more information throughout the week, with the hope that any questions about water contamination are firmly in the rearview by next week.

Since the Friday spill, the city has been continually testing the water coming into the Baxter Treatment Plant, Philadelphia’s primary water treatment facility that draws from the Delaware River. Thus far, no contaminants have been detected, though officials say the chemicals involved aren’t due to fully float pass Baxter until Wednesday or Thursday this week. After they do so, officials believe that these concerns should be fully behind them within a few days.

For now, officials are encouraging people to store water, and suggesting that they follow FEMA’s guidance of having three days of water on hand, which includes one gallon per person per day. City officials also said they are preparing a water distribution plan if they detect an unsafe level of contaminants in the water that Baxter is taking in. This incident, ultimately, is yet another development that renews attention to gaps in the country’s water infrastructure as well as the government’s ability to respond to chemical spills.

What happened with the Philadelphia chemical spill

The spill of 8,100 to 12,000 gallons of chemicals into the Delaware River occurred on Friday evening shortly before midnight at the Trinseo PLC Plant about eight miles north of Baxter. That plant, located in Bristol, Pennsylvania, in Bucks County, manufactures acrylic resins, and uses materials like those found in latex paint. Due to what the company described as an “equipment failure,” its facilities were unable to contain the chemicals — a solution of 50 percent water and 50 percent latex polymer — which then spilled into Otter Creek and then the Delaware River.

Philadelphia officials are now monitoring the water in and near Baxter for three of the main chemicals involved in the incident — butyl acrylate, ethyl acrylate, and methyl methacrylate — all of which can cause irritation if ingested, but should not be especially toxic in small concentrations, says Drexel University environmental and occupational health professor Arthur Frank.

Currently, the Coast Guard is working with state and local agencies to clean up the contaminated water, with 60,000 gallons collected so far. Michael Carroll, a city official, also noted that both rain and tides in the river should help it “flush itself out” this week. Philadelphia residents can get the latest updates via the city’s website as well as from its Twitter account.

Frank added that the size of the spill should reduce any potential health effects. “We have a situation where a lot of it was contained at the site of the spill but a lot of it that ended up in the creek, and in the Delaware, it’s going to be massively diluted,” he told Vox, noting that these chemicals only tend to affect people when they’re in higher concentrations. “The health effects of these materials are generally going to be seen in workplace settings at high levels of exposure.”

One of the chemicals involved in the spill, butyl acrylate, is among those found in the East Palestine train derailment, a massive spill that happened earlier this year, which underscores the need for more guardrails on companies to prevent such accidents. There are important differences between the two, too: “Unlike the toxins spilled in the Ohio chemical spill after the major train derailment, environmental experts are adamant that the material shouldn’t be a concern to the public,” ABC News reports.

The problems with US drinking water

Because of aging infrastructure, the US has experienced several major drinking water incidents in recent years with cities including Jackson, Mississippi, and Flint, Michigan, going for days without safe tap water. In both of these places, old pipes have led to lead contamination in the water or water main breaks that have allowed unsafe contaminants to leech in.

In Philadelphia’s case, the inciting incident is due to a specific chemical spill rather than a problem with the city’s infrastructure. Still, Frank notes, it draws attention to other problems the city has had with drinking water in the past, and the gaps it continues to have in its facilities. It raises questions about filtration, for example, and whether the city needs better equipment to handled contaminants like these. Last year, Philadelphia also struggled with issues of lead contamination in the tap water in some schools.

Additionally, Frank emphasized that this incident is a reminder that the government still needed to bolster resources that allows quicker responses to chemical spills. Officials in the area said they were stretched thin following the train derailment in Ohio, an issue that may have taken more time to rally a response. “It took us a little while to gather the resources as the Ohio incident is still draining a lot of resources regionally,” Samuel Manka, a marine science technician with the US Coast Guard, told ABC News.

There are also outstanding questions about the role of government and regulation in avoiding accidents altogether. The chemical spill in Ohio, for instance, has fueled bipartisan legislation to impose new safety requirements for trains carrying hazardous materials. Meanwhile, Drexel environmental engineering professor Charles Haas told Vox that regional officials could ramp up their reviews of businesses located near the Delaware River. Greater oversight could identify whether companies are at risk of leaks like this one, which would help them assess how much of an issue it could be for them to operate near such water sources.

“We have a woefully unsupported infrastructure system on the water side and we have companies that had a problem that was likely preventable,” says Frank.