MCKEESPORT (KDKA) – Hundreds of McKeesport residents still can’t drink or use their tap water after concerns of possible contamination from a fire-fighting foam.

The Municipal Authority of Westmoreland County said crews started flushing the system as a precaution on Saturday but they ran into some problems.

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They discovered an older piece of pipe that’s preventing effective flushing and it will be replaced overnight, according to Matthew Junker with MAWC.

The county alerted residents Saturday morning to not use the tap water to drink, bathe, cook, or anything because a firefighting foam may have been sucked into a fire hydrant during a fire at a McKeesport Auto Body on Friday.

Watch KDKA’s Bryant Reed’s report:

The advisory said the foam contains PFAs and glycol, which may be a serious health concern if in drinking water.

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The county is waiting for test results and flushing the system to be safe.

About 500 residents are affected. Many of them are frustrated as they anxiously wait to be able to use their water again.

“We have bottled water, and we utilize the buffalos out here. It’s just tiring having two kids and having to try to get enough water to get them in the tub, wash them up, but what can you do though?” said Jason Pollitt, a McKeesport resident.

There are water buffaloes on Atlantic Avenue at the sewage plant and at R&W oil. There’s also bottled water at the McKeesport fire department.

Officials also said to not boil the water and try to use it.

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The county will notify residents of any changes.