San Mateo County schools' drinking water contaminated with nitrate

Thursday, November 2, 2023
San Mateo Co. schools' drinking water contaminated with nitrate
Water is contaminated with nitrate Pescadero Middle and High School in Pescadero. It's a decades-old problem that resurfaced in a science classroom.

PESCADERO, Calif. (KGO) -- Drinking water is contaminated with nitrate at two San Mateo County schools. It's a decades-old problem that resurfaced in a local science classroom.

"It's horrible looking right now," said Cullen Rose, the high school science teacher. "I knew just looking at it, I can't drink this."

Pescadero Middle and High School has periodically seen high levels of nitrate for decades. It's a fertilizer chemical that's known to contaminate drinking water in agricultural areas. Because of the chemical, the school's drinking faucets are shut off and students have relied on shipments of bottled water for the past 25 years. But recently, teachers say those shipments have been unreliable.


You can't taste it, smell it, or even see it in the water. But according to the Environmental Protection Agency, consuming too much can reduce the ability of blood to carry oxygen, which can turn your skin blue, cause cancer, and in some cases even be deadly.

"It's disgusting," said San Mateo County Supervisor Ray Mueller. "It's contaminated not only with nitrates but with magnesium oxidation."

Image shows a photo of a toilet bowl contaminated with nitrate at Pescadero Middle/High School in Pescadero, Calif.
Image shows a photo of a toilet bowl contaminated with nitrate at Pescadero Middle/High School in Pescadero, Calif.

According to the EPA, you can't see nitrate in water but when mixed or contaminated with other chemicals or compounds, the water looks dirty.

"It's like yellow-brown," said student Jessica Garcia. "It's uncomfortable to see that when you wash your hands."

The picture below was taken in October after a beaker was filled with water from the faucet in the high school science classroom.

Image from October shows a beaker filled with water from the faucet at Pescadero Middle/High School in Pescadero, Calif.
Image from October shows a beaker filled with water from the faucet at Pescadero Middle/High School in Pescadero, Calif.

The water supply problem

"Since we can't drink our water from the sink, we have a water station in every classroom," said Garcia. "But, sometimes we run out of water."

When asked how often, Garcia said "too many times."

Greg Virgallito is the school's physical education teacher. He says it happens more than it should, usually on hot days.

"Deliveries can be spotty, we often run out," said Virgallito. "It can be cause for a real possible health situation."

How Pescadero stands out

ABC7's analysis of state drinking water data found Pescadero Middle and High School are the only schools in the county to have nitrate failure as of right now, according to the state Division of Drinking Water, which identifies failing and at-risk water systems in the community and at K-12 non-transient, non-community schools. Across the region, three other areas also failed - including Twin Valley, Inc. in Morgan Hill, Valley Ford Water Association in Valley Ford and the Robin Way Water System in Santa Rosa.

In Pescadero, the district says the latest water test from Oct. 12 showed 5.3 milligrams of nitrate per liter with no bacteria. The superintendent Amy Wooliever told the I-Team bacteria has not been detected in the water in the past and samples are taken from the school taps.

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But earlier this month, Cullen Rose, the high school science teacher says experiments by students found higher rates of bacteria washing their hands using the school water than without.

"What we found in our results is that a hand sanitizer was much better at cleaning the bacteria off our hands than the school water here," Rose said. "Whereas, when we did our research beforehand, washing your hands with soap and water should be more effective than hand sanitizer."

According to Rose, students came to the conclusion that's due to the water. Some of the students raising concern that the water may be adding bacteria onto their hands.

"They deserve better," Rose said.

MORE: These are challenges the Bay Area faces in eliminating 'forever chemicals' in water, experts say

Students told the I-Team they see evidence of the problem from the toilet to the faucet.

Teachers told the I-Team the water is even too toxic for the plants.

"It will just kill the plants because the amount of sediment in it," said Rose.

Video taken by the I-team on Oct. 26 shows muggy water from the school faucets next to clean bottled water. According to documents obtained by the I-Team, nitrate levels began exceeding the maximum state and federal limit in February 2014 when one well was measured at 14 milligrams per liter. That's 40% over the legal limit of 10 milligrams per liter.

The nitrate limit was exceeded again in December 2014, October 2015, and several times in 2017. From then on the district has been required to test for nitrate and bacteria on a monthly basis. The district says they also test for lead and copper every year and complete a series of 30 to 40 other tests every three years.

The proposed solution

The county has been discussing plans to connect clean water to Pescadero Middle and High School since 2020. It involves relocating a local fire station with maintenance of an underground water line to be able to source clean water to the school.

It's called the Fire Station 59 Relocation Project.

Supervisor Mueller says the project has bit a big roadblock: a regulation imposed on the county to preserve agricultural land.

"Well, it's frustrating as a new county supervisor," said Mueller. "I've been on the job 10 months and to be hearing from constituents what's holding this project up - is a regulation that's being imposed on the county that we can't meet."

According to Mueller, the California Coastal Commission oversees development in this area and requested the county implement a two to one land replacement where the new fire station would go, which is approximately 3.5 acres. Among other things, he says the commission requires it be prime agricultural land and that land be relocated within a reasonable distance of the existing site.

"So it's exceedingly difficult," Mueller said. "And for two years, the county hasn't been able to meet that requirement."

But, not everyone agrees moving the fire station is the right solution.

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"We need to really look at our finances and how spending can be done efficiently and effectively," said Pescadero resident, Bridget Jett. "I think that the firehouse where it is, is a good place. And the firemen deserve to have an excellent state of the art facility. And I think we could do that at the existing location."

BJ Burns, the president of the San Mateo County Farm Bureau, agrees. He's also the owner of Bianchi Flowers Ranch right across the street from the school grounds.

"It just doesn't make sense," said Burns. "You don't need to move a firehouse to get the water."

Burns told the I-Team he wants the project to be researched more before millions of taxpayer dollars are spent.

"Well, I've heard it will cost up to $12 million just to move a firehouse out here," said Burns. "And I've heard it will cost between $5 million to $6 million to bring out a water line. And to me, that's just a waste of money, especially when the location of the fire department right now is in the right place."

According to the district, in 2019 the county drilled for a new water well, but it did not have sufficient flow to support the school.

Four years later, students still don't have clean running water.

Take a look at more stories by the ABC7 News I-Team.

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