Water bottle shelves at a supermarket in Philadelphia sit empty Sunday following a chemical spill in the Delaware River.
Philadelphia CNN  — 

Philadelphia residents can continue using tap water as normal until at least 3:30 p.m. Tuesday following a chemical spill a few miles upstream of a key intake in the Delaware River, city officials said Monday.

Michael Carroll, the city’s deputy managing director for transportation, infrastructure and sustainability, said at news conference Monday afternoon that water quality was being tested around the clock, with the latest results at 4 p.m. – an hour before the conference.

“Your tap water is and remains safe,” he said. “So use your water as you normally would.”

Officials said the contaminants from Sunday’s spill should be clear from the river by Thursday.

Late Monday morning, city officials posted online that they were “confident tap water from the Baxter Drinking Water Treatment Plant will remain safe to drink and use at least through 11:59 p.m. today,” repeating the timeframe they laid out Sunday when they explained water available before that time would have been treated “before the spill reached Philadelphia.”

But the assurances – following leaders’ initial recommendation that residents use bottled water starting Sunday at 2 p.m. – is causing confusion, concern and anger in the busy East Coast hub, where some grocery shelves are already empty of water.

Carroll said Monday that communication was “a difficult balance.”

“Everything we have done to communicate with the public has been done in the interest of both transparency and out of an abundance of care and caution to make sure our people are safe,” he said. “Based on that, we may be overcommunicating with people, and as a result, maybe we’re elevating folks’ anxieties. It’s a difficult thing to balance.”

Carroll also said Sunday’s guidance had changed for “convoluted” reasons. “What I want to emphasize is that when we had information, we provided it.”

Earlier Monday, South Philadelphia resident Joe Sole spoke to CNN from a grocery store parking lot as he loaded packages of bottled water into his car, saying, “I don’t trust the city.”

“They sound like they don’t really know what they’re talking about,” he added. “They don’t sound confident in what they’re telling us.”

Joe Sole, a resident of South Philadelphia, talks about the city's drinking water alert.

The spill “appears to be the result of equipment failure” at a Trinseo PLC plant that makes acrylic resins, the owner said Sunday, and it raised immediate concerns about possible health threats. At least one of the discharged chemicals, butyl acrylate, is among contaminants of concern identified in last month’s train derailment in East Palestine, Ohio.

Ethyl acrylate and methyl methacrylate also spilled into the Delaware River, officials said.

“Butyl acrylate, in particular, is a chemical that was identified in the spill in East Palestine. So, we understand there are some known health effects and their established thresholds in terms of the parts per billion that the EPA feels are safe,” Carroll told reporters Sunday.

The water would continue to be monitored, Carroll said, adding the “potential for contamination is diminishing over time.”

“Again, I want to reiterate, we have not detected any of these contaminants in our water and will continue to use that as our first basis for any decision-making that we make.”

The city’s advice on the tap water’s safety was updated “based on the time it will take river water that entered the Baxter intakes early Sunday morning to move through treatment and water mains before reaching customers,” it said in a statement.

Philadelphia Mayor Jim Kenney on Monday acknowledged residents’ anxieties, saying in a news release officials understood “the legitimate concern that is felt by the public as the release of chemicals into our waterways can pose a major threat to our health and safety.”

“The Philadelphia Water Department is working around the clock to ensure that this does not happen and that our water remains safe to drink and use,” said Kenney, encouraging residents to store tap water as he remains “confident that there is no risk at this time.”

During Monday’s news conference, officials reiterated advice that residents should have three days’ worth of water on hand, but said it was possible that contaminants from the spill might not enter the city’s water supply at all.

Philadelphia Water Commissioner Randy Hayman emphasized that testing takes time.

“Our main tool in addressing this (contaminant) problem is testing – old-fashioned testing,” he said. But he said collecting water samples and analyzing them took time. “That’s why we have to be patient.”

The Philadelphia Water Department provides water to more than “2 million people in Philadelphia, Montgomery, Delaware, and Bucks counties,” its website says. It is posting online updates regarding the spill.

Early advisory sent in ‘abundance of caution’

Philadelphia officials initially sent out mobile phone alerts recommending residents use bottled water beginning at 2 p.m. Sunday due to the spill, only to say later that afternoon they were confident tap water from the Baxter Drinking Water Treatment Plant – about 8 miles downstream of the facility where the spill occurred – would remain safe to drink until at least the end of Monday.

The earlier advisory, the city said, “was issued out of an abundance of caution,” and the new guidance followed “updated hydraulic modeling and the latest sampling results and data.” None of the three chemicals that leaked into the river when a latex product spilled Friday in Bristol, Pennsylvania, had been detected in Philadelphia’s water system by Sunday evening, city officials said at that time.

This alert was sent to Philadelphia residents.

By then, however, residents had already swarmed grocery stores to stock up on bottled water as news of the spill – and health worries – spread. Among them was Kim Kelly, a “gallon-a-day kind of gal” who on Sunday found some shelves bare at one South Philadelphia store.

“It’s not the sort of thing you want to mess around with,” she said. “I feel like someone should reimburse all of us for all the money we’re spending on all this water because it’s not our fault.”

Sole didn’t rush out to buy bottle water after receiving the first alert Sunday, he said. But by late Monday morning, he made the trek, conceding he and his wife were “afraid to drink the regular water.”

Sole didn’t know how he could be convinced the tap water’s safe, he said. It could just take time.

“Look what those people went through in Ohio,” he said, referring to residents of East Palestine. “It’s the same. They believed it, too, and look what happens. You just can’t trust them.”

How the spilled chemicals can harm health

No evidence of contamination plumes was seen during a flyover by the Philadelphia Police Department and Pennsylvania Department of Environmental Protection, Carroll told reporters Sunday.

“In this case, because we were talking about essentially ingredients that go into latex paint, we would have been able to see a kind of white plume under the river surface,” he said.

Some 60,000 gallons of contaminated water had been collected from the spill, the Coast Guard said in a statement Sunday night. “Clean-up is primarily focused on removing product from the storm drain system and outflow located on Mill Creek,” it said.

Coast Guard pollution responders conducted shoreline patrols Sunday morning and observed no visible product along the Delaware River, the statement reads. The Coast Guard had not gotten any calls reporting injured or affected wildlife, it said.

That was echoed by a statement Monday from the Pennsylvania Fish and Boat Commission, which was monitoring for any impact on fish or aquatic life.

“At this time, we have not observed any dead aquatic life associated with this pollution event,” the commission said.

Among the chemicals that spilled:

Butyl acrylate is a potentially flammable colorless liquid with an acrid odor which can cause irritation of the eyes, skin and respiratory system, according to the US Centers for Disease Control and Prevention’s National Institute for Occupational Safety and Health.

Ethyl acrylate can cause irritation symptoms depending on exposure, the CDC says. Both are often used in the manufacturing of paints and adhesives.

Methyl methacrylate, sometimes called MMA, is a colorless liquid with a fruity odor often used in the production of acrylic plastics and resins. Exposure to MMA can cause irritation to the eyes, skin, nose and throat as well as skin inflammation. The polymer version of MMA is often used in dental applications.

Early warning system alerted officials to spill

The contamination occurred Friday night and involved a latex product that spilled along a Delaware River tributary in Bristol Township, Bucks County, Carroll earlier said in a statement.

“The Philadelphia Water Department (PWD) became aware of this through the Delaware Valley Early Warning System (EWS) and has been evaluating the situation since that time to understand potential impacts to the public,” the statement reads.

An estimated 8,100 gallons of solution – half water and half latex polymer – was spilled, Trinseo PLC said Sunday in a statement on its website.

“The latex emulsion is a white liquid that is used in various consumer goods. Its pigmentation makes the water-soluble material visible in surface water,” Trinseo said.

The Pennsylvania Department of Environmental Protection said an “unknown amount” of the spilled product had entered the Delaware River. Fish and wildlife are said to have not been affected, according to the statement.

“Since the first hours after the incident, the Department of Environmental Protection has been at the facility where the spill originated and will be staying until there is no longer a threat to those impacted in Bucks and Philadelphia counties,” the department’s acting secretary Rich Negrin said in the statement.

“We are working closely with our partners to monitor the spread of the contaminants and we will hold the responsible party accountable.”

CNN’s Polo Sandoval, Samantha Beech, Zenebou Sylla,Celina Tebor and Danny Freeman contributed to this report.