San Diego

How Did Poway’s Water System Become Contaminated?

Mother Nature and mechanical failure led to the contamination of Poway's potable water supply, prompting a Precautionary Boil Water Advisory that could last several more days

Poway residents were still being told to boil their water Tuesday as crews continued to remedy a water contamination problem caused by heavy rains over the Thanksgiving holiday.

The city of Poway issued its first ever "Precautionary Boil Water Advisory" Saturday after residents reported "discolored water" coming from the taps on Friday, the city said. The heavy, recent rain storms compromised the potable drinking water system, according to the city.

How did that rainwater make its way into the city’s water system, though?

The city’s clearwell reservoir is the final container system for filtered water at the Lester J. Berglund Water Treatment Plant near Lake Poway and it looks like a huge swimming pool with a covering over it.

When the container is at risk of overflowing, a door opens to let water flow out into a storm drain, the city said.

The city says a faulty flap gate was somehow stuck open, and when the storm drain backed up due to a heavy storm the open flap gate allowed contaminated water to spill back into the clearwell reservoir.

That door is now sealed shut, the city said, and workers were in the decontamination process, draining the north half of the clearwell and disinfecting it on Tuesday.

Looking to the future, the city installed a sensor to the storm drain that will alert staff if a certain amount of stormwater is nearing the system.

Mayor Vaus answers some frequently asked questions about the boil advisory in place.

On Tuesday, a city spokesperson said two certified test results of the water met industry standards and the water is absent of bacteria. Poway will continue to follow mandated state protocols for the precautionary boil water advisory, the city said.

Mayor Steve Vaus said, "Actually the water is well within our standards for drinking. I’m still drinkin’ it, but the state, they’re a little more skittish. Sacramento works in strange ways, so we’re giving out water to make sure our folks are taken care of.”

Some critics pointed to a capital improvement project as the cause for the issue, but the city said that’s not the case.

“What they found is just another capital improvement project for us to handle. We want to maintain all of our facilities including the water treatment plant,” Jessica Parks with the City of Poway said.

Councilmembers didn't have many answers to give but they did their best to explain what went wrong. NBC 7's Jackie Crea has more.

Going on day four of the boil water advisory, Poway residents flooded Tuesday night's city council meeting looking for answers. And while councilmembers didn't have many to give, they did their best to explain the situation to restless community members.

The meeting began with a public works spokesperson showing a diagram of the city's water treatment site and explaining the cause and clean up efforts.

There is no timeline for when the advisory will be lifted. Thus, bottled water distribution will continue at Lake Poway and City Hall from 7 a.m. to 6 p.m. on Wednesday.

Residents told NBC 7 they were most concerned for the many restaurants forced to close due to the advisory. They’ve created an impromptu restaurant month to help restaurants get back on their feet.

NBC 7's Jackie Crea heard from a mother who's trying to get her community to support the local restaurant industry.

Poway's water initially comes from the Colorado River and Northern California, according to the website.

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