Water fountains at the new M.S. 839 can fill up bottles. View Full Caption DNAinfo/Leslie Albrecht

MANHATTAN — Roughly 83 percent of 1,544 school buildings across the city had elevated lead levels in their water in the past six months, according an analysis of Department of Education data released Friday.

There were 1,281 school buildings across the five boroughs where city inspectors found at least one sample of water with more than 15 parts per billion (ppb) lead levels, which is the federal action threshold. That number — found under more stringent testing ordered in September by Gov. Andrew Cuomo following concerns about tainted water elsewhere across the nation — was dramatically higher than the 509 buildings the city reported had elevated lead levels last year.

Schools found to have at least one elevated sample included:

►Manhattan: 88 percent of 234 school buildings

► Brooklyn: 87 percent of 469 school buildings

►Staten Island: 82 percent of 98 buildings

►Queens: 80 percent of the 408 school buildings

►The Bronx: 76 percent of 332 buildings

There were 123 schools with more than a quarter of elevated samples, including:

► 57 in Brooklyn

► 29 in Queens

► 17 in the Bronx

► 11 in Manhattan

► 9 in Staten Island

William Grady Career and Technical High School in Brighton Beach, Brooklyn had the highest number of elevated samples — with 101 fixtures with lead in the water above the allowable ppb.

The city collected a total of 132,000 samples from potential drinking water sources, and found that a total of 8 percent were found to have lead levels high enough to be of concern under federally allowable guidelines, the figures showed. Of those, 1.5 percent of the elevated samples came from drinking fountains in particular.

DOE officials emphasized that the city’s water is safe for students and staff to drink and that the city school figures are lower than the statewide average of 14 percent of samples with elevated levels.

Still, the number of outlets with lead is up significantly from a less rigorous round of testing completed last school year, which reported only about 1 percent of samples had results over 15 ppb.

Last year’s testing protocol came under fire after experts found the city had been running the water pipes the night before testing against recommendations from the U.S. Environmental Protection Agency.

All cooking and drinking water fixtures with lead levels found over 15 ppb were immediately taken out of service, DOE officials said, and they were only restored to use once they were replaced and once subsequent tests showed lead levels below 15 ppb.

► READ MORE: Here's What You Need to Know About Lead Water Testing in City Schools

Under the terms of Cuomo's state executive order, the city was required to notify families at schools across the city with the results of their children’s school lead tests within 10 days of the school getting the results.

The letter and the complete lab reports, including the specific locations of each outlet, and what its lead levels were in ppb are now posted on each school’s website, with translated versions available in 10 languages.

The city's Friday lead data was hailed by Marc Edwards, the Virginia Tech professor who helped uncover the water crisis in Flint — but he cautioned that lead levels in water are not a fixed condition.

"NYC should be applauded but should remain vigilant. A tap that tested good today, can dispense dangerous levels of lead tomorrow, as long as lead is in the plumbing."

DOE Deputy Chancellor Elizabeth Rose called the lead in school water "minimal."

“As our citywide test results confirm, the number of elevations are minimal and we take immediate action to remediate all fixtures with results above 15 ppb. We have shared detailed information with schools and families, and will continue to keep communities updated.”

The city only included detailed information about each school's exact lead levels on the individual schools' websites, and did not include it in their much-touted "Water Safety Portal."

“Families should rest assured that water in schools is safe for students and staff to drink,” Rose added.

But there’s still debate whether 15 ppb should be the threshold for what’s considered safe.

The American American Academy of Pediatrics this summer urged a change in new federal standards to ensure that water fountains in schools do not exceed water lead concentrations of more than 1 part per billion rather than the current 15 parts per billion allowable now.

First Deputy Health Commissioner Dr. Oxiris Barbot noted that since 2005 the city has seen an 86 percent drop in lead poisoning cases among children.

“We feel confident that the DOE is taking the right actions by taking drinking fixtures that have had lead exceedances off line until they can be replaced,” she said in a statement. “Generally, these elevated levels are not reflective of the water children drink throughout the day, but concerned parents should speak to their child’s health care provider.”

Levels tend to be more elevated when water has been stagnant, after a fixture hasn’t been in use for several hours — which is why the city urges New Yorkers to run their tap in the morning for at least 30 seconds. Health officials believe that the fixtures with elevated levels would see those levels then decrease during the day.

Risk associated with lead also depends on how much a child is consuming and the size of the child, which is why there’s greater concern about lead poisoning with smaller children. While children under the age of 3 are required to have their lead levels tested, school-age children are not required to do so — and some watchdogs believe that the new data should force the city to reconsider that.

“Given that 83 percent of school buildings had outlets with water above the legal limit, this is a problem that should not be minimized,” said Leonie Haimson of the advocacy group Class Size Matters. “The DOE should also consider testing blood levels of students at schools found to have high concentrations of lead in their water.”

But Edwards said once a child is exposed to high levels of lead, "The harm that was done cannot be undone."

He added that parents who are considering blood tests for their children in light of the lead levels may have already missed the window "since evidence of harm disappears after about 30 days of removing the exposure, any blood lead testing would just create a false sense of security."

2017 NYC DOE Water Tests Results Summary(2) by DNAinfoNewYork on Scribd

Correction: An earlier version of the story incorrectly estimated the ratio of affected schools.