It took a dog to protect children from lead in the water at one San Diego school.
On January 26, a therapy dog at San Diego Cooperative Charter School in Mountain View wouldn’t drink the water a teacher had poured from the classroom sink.
A teacher then noticed the water had a sheen, similar to the appearance of oil on water. When district officials sampled water on the campus, they found the presence of vinyl chloride, a carcinogen, which likely came from degraded plastic plumbing materials, known as PVC pipe.
It turns out the oily sheen was less of a concern than the lead that follow-up tests revealed.
The charter school shares a campus with the Emerson-Bandini Elementary School. Officials took 10 water samples from fountains and sinks on campus. Those tests revealed water from three different sources contained more than the allowable limit of lead . The water at one sink contained more than twice the allowable limit. Lead can damage children’s brains.
Now, officials are setting off to test every school in the district. So far, the only district school that’s been tested for lead turned up positive, which could indicate a larger problem for San Diego Unified and its students.
District officials say they started providing bottled water to the Emerson-Bandini campus on January 26, the day the therapy dog refused to drink the water.
But NBC reported  that when a reporter visited the campus on March 1, the water was still running and no signs told students to steer clear of the fountains.
“The water is just fine but we don’t drink from it,” third-grader Francisco Orejel told the television station. “We get cups. We get bottled water sometimes.”
But the water wasn’t fine.
Emails obtained by NBC reveal that school officials had good reason to be concerned about the water for at least a month before the Emerson-Bandini principal sent a letter home to parents, on March 24, notifying them the school would switch to bottled water until the lead contamination is resolved.
Findings from preliminary field tests and observations, noted in an email a water consultant sent to a district official on February 21, indicated:
• Reports of a chemical odor in the water at the charter school
• Reports of a blue tinge to water at the charter school
• Reports from a school nurse who said several charter school students experienced nausea and vomiting following consumption of the water
• The presence of elevated levels of disinfection byproducts in one sample collected from the charter school
• The presence of vinyl chloride in one sample collected from the charter school
Emerson is the second elementary school in San Diego to report having unacceptable levels of lead in recent months.
In January, the San Ysidro School District found that eight classrooms in La Mirada Elementary also had too much lead in their drinking water.
Both La Mirada and Emerson-Bandini use water from the city of San Diego’s water department. The city’s water is not the likely cause of the problem, though. Instead, the likely cause of the lead pollution is fixtures and pipes inside the schools themselves. In San Ysidro, the district superintendent blamed the pollution problem on aging facilities .
How many other schools might have polluted water? We don’t know.
San Diego’s water department does routine tests of water leaving its treatment plants, but that does not catch problems that may be showing up when water reaches people’s homes or, in this case, schools.
The city is also required to sample homes across the city every few years to see if deteriorating indoor plumbing is poisoning customers. As clean water passes through indoor plumbing, metal in pipes and fixtures leaches into the water.
Schools, however, are not required to do these tests.
The discovery of lead in two schools in the past four months shows the holes in the regulatory regime.
In 2014 and 2016, the city sampled 54 and 21 homes, respectively, for lead and copper. That’s a small number for a big city, but it’s all that is required by law. The city is supposed to pick places to sample based on risk.
While there is no safe level of lead in drinking water, regulators become alarmed when they see lead at levels higher than 15 parts per billion in water. Water taken from one location at the charter school contained lead at 38.6 parts per billion .
It’s not clear that the city took samples in the neighborhoods where Emerson-Bandini and La Mirada are. It’s not clear because water testing records provided to Voice of San Diego by the state’s Division of Drinking Water only give the zip codes of where tests were done. Some locations were redacted entirely.
However, according to what is visible in those records, one area received significant testing: Twenty-five lead samples were taken in Linda Vista.
City-wide, only two sites turned up alarming levels of lead — one place in Old Town and another in Rancho Bernardo.
In other words, because of the recent school tests, there’s been as many places found with alarming levels of lead in the past four months as the normal testing cycle found in the past four years.
Perhaps Emerson-Bandini and La Mirada are outliers, but they reveal the extent to which we are in the dark about water quality in San Diego.
“While there might be testing of water for contaminants as part of routine maintenance or if there is a water quality complaint, it is my understanding that there has not been district-wide water testing in recent memory,” Samer Naji, a spokesman for San Diego Unified, said in an email.
To try to fix this hole in the water quality safety net, the State Water Resources Control Board has asked water agencies across California to begin testing schools for lead, if the schools request a test.
That program is at least partly a response to the water crisis in Flint, Michigan, where thousands of children were exposed to high levels of lead in their drinking water.
There are other issues closer to home: A major investigation by Reuters showed that Fresno has higher rates of lead poisoning than even Flint . Data compiled by the news agency also shows small but detectable levels of lead poisoning in neighborhoods across San Diego County .
Lead is toxic to the nervous system and to the brain and, even at low levels , can change children’s behavior and reduce their IQ.
San Diego Unified and the city water department plan to test all schools by the end of the school year, starting with schools in Southeastern San Diego – where the oldest schools are located – and moving toward newer schools in the north and west.
That testing pattern also corresponds with economic status. The schools in Southeastern San Diego have some of the highest concentrations of poverty in the district. The most affluent schools are in the north and west.
The most important factor when determining risks for lead contamination is the age of the building’s plumbing system and the type of plumbing fixtures, which can add contaminants to the water at the school site just before it is used by students and school staff.
“We are honing in on what’s the source,” Drew Rowlands, the district’s chief operations officer told NBC 7 this week  in response to questions about Emerson-Bandini.
“But In all likelihood, it’s part of our plumbing. Who’s to say how long it’s been there,” Rowlands said.
The district says it plans to publically post results from the water tests at other as soon they’re available. You can find those results here .