New York Today: So Long, Sweaty Summer

New York City said on Friday that it would adjust its procedure of testing for lead in the water supply of schools, after experts said the city’s methods could lower the levels found.

Between March and June, the city tested the water in all 1,520 occupied school buildings. The night before taking samples, the contractors who conducted the testing arrived at the buildings and let the water run from all outlets for two hours, a practice known as pre-stagnation flushing. An investigation by The New York Times uncovered the practice, which cleans pipes of soluble lead and lead particles, and thus can result in samples with lower than normal lead levels.

The Environmental Protection Agency’s voluntary guidelines for testing water in schools do not mention pre-stagnation flushing, and the agency has recommended against it when testing water in people’s homes.

In July, the city said that less than 1 percent of samples tested had lead concentrations that exceeded the agency’s “action level” of 15 parts per billion.
But Marc Edwards, a civil engineering professor at Virginia Tech, said that a long period of flushing would have skewed the results significantly and that the city should throw out the test results and start over.

City officials initially defended their methods, saying the pre-stagnation flushing did not affect the accuracy of the test results. They said the flushing protocol was developed for testing during the summer, when many school buildings are empty, to mimic normal water use, and then extended to all tests.

On Friday, the city changed course — partly. A spokeswoman for Mayor Bill de Blasio, Freddi Goldstein, said that in the future the city would try to conduct as many tests as possible while school was in session, and on mornings other than Mondays, and that for these tests it would abandon the pre-stagnation flushing step. But she said the city would continue doing the pre-stagnation flushing when it was necessary to collect samples on Monday mornings or over school holidays.

Ms. Goldstein said that starting in October, the city would retest every building that had at least one water sample that exceeded 15 parts per billion of lead (there were 510 of them). The city will also begin retesting the buildings that did not have any samples over that threshold.

In buildings where one or more sample exceeded the E.P.A.’s action level, the city has removed those outlets and also instructed its staff to flush all of the outlets in the building briefly every Monday morning. It has said that those steps will protect children from consuming water with high levels of lead.

SOURCE: New York Today
By By KATE TAYLOR
http://www.nytimes.com/2016/09/03/nyregion/new-york-city-will-change-lead-testing-methods-at-its-schools.html

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