NewsChannel 5 Investigates first revealed that, as part of its lead-testing program, Metro Nashville Public Schools utilized a testing method that masks the real contamination problem in its drinking water.
MNPS responded by posting a claim on its website that “EPA VALIDATES METRO SCHOOLS’ LEAD TESTING PROTOCOL.”
But our investigation discovered there's a lot more to the story.
Back in May, our investigation revealed that the district uses a protocol – called “pre-stagnation flushing” – that essentially washes away the evidence before workers collect water samples.
A maintenance worker brought us a bottle of highly contaminated water from a fountain that MNPS’ own tests had shown was clear, using pre-stagnation flushing. The top expert from Flint, Michigan, said MNPS’ results “need to be thrown right in the garbage” and the district needs to start over.
Ask Metro Schools, and they'll point to the EPA's published guidance for schools that says: “Ideally, the water should sit in the pipes unused for at least 8 hours but not more than 18 hours before a sample is taken.”
MNPS has used that one sentence to justify sending crews out to schools to completely flush out the water lines the day before the samples are collected. Experts say that skews the results.
So, NewsChannel 5 Investigates reached out to EPA headquarters for clarification.
A spokesperson noted that EPA “also recommends collecting samples when there are standing times outside this range, so long as that time is representative of typical use patterns at that outlet.”
In other words, the tests should reflect the actual conditions under which students and staff normally consume water.
Go back to the sentence that MNPS likes to quote. It says that, “ideally,” the water should not be stagnant for more than 18 hours.
But read the next two sentences.
“However, water may be more than 18 hours old at some outlets that are infrequently used. If this is typical of normal use patterns, then these outlets should still be sampled.”
Later, in that same document where MNPS found the one sentence it likes, EPA says that testing should be “representative of the normal water consumption pattern.”
In 2016, after the Flint water crisis, the EPA issued a "clarification" for public drinking water systems that pre-stagnation flushing does NOT represent a best practice.
“Pre-stagnation flushing may potentially lower the lead levels as compared to when it is not practiced,” wrote Peter C. Grevatt, director of the EPA’s Office of Ground Water and Drinking Water.
“Flushing removes water that may have been in contact with the lead service line for extended periods, which is when lead typically leaches into drinking water. Therefore, EPA recommends that sampling instructions not contain a pre-stagnation flushing step.”
According to emails obtained through a public records request, MNPS spokesperson Michelle Michaud got an Atlanta EPA official to say that Grevatt's memorandum “does not apply” to schools.
But the email chain indicates that MNPS never asked EPA whether pre-stagnation flushing is a good idea.
In fact, after the issue was raised in New York City schools, the district retested all its fixtures and discovered that the actual lead contamination problem was much worse than initial tests showed.
New York City's Department of Education developed protocols that actually follow the EPA guidance for schools AND include language that “there will be NO pre-stagnation water flushing, unless NYC DOE is specifically directed to do so by the State or Local Health Department.”
During the special election for mayor, David Briley promised to “look into” questions raised by NewsChannel 5 Investigates about MNPS’ testing protocols.
So far, children are still drinking water that’s been tested after the worst contamination has been washed away.
NC5 Investigates: Lead in School Water