Data flag classroom sinks in school lead exposures

Nearly half of all classroom sinks tested in Lincoln County schools require action to remove unsafe levels of lead in drinking water, according to the Department of Environmental Quality.

Greg Montgomery, a lead rule manager for the DEQ, said classroom sinks throughout Montana have been identified as the most problematic fixtures delivering potentially high doses of lead to students and staff.

Montgomery recently presented county-specific data to the Lincoln County Health Board. He said sampling so far had been completed at 13 accredited schools, with results now available from eight facilities in Eureka, Trego, Yaak and Troy.

Libby schools have not yet completed sampling, according to the DEQ.

Of 299 total county samples — from drinking fountains, as well as kitchen, bathroom and classroom sinks — 70 samples, or nearly a quarter of all fixtures tested, contained lead levels requiring remediation by the state.

Montana officials place sampling results into three remediation categories referred to as “bins”.

“Bin 1” includes samples containing more than 15 micrograms of lead per liter of drinking water.

The threshold coincides with the maximum concentration of lead allowed in public drinking water by the U.S. Environmental Protection Agency.

Lead levels found at or above 15 micrograms require the immediate shutoff of associated water fixtures and plumbing, and then corrective action by schools.

That could include a fixture being fixed, removed or replaced.

“Bin 2” includes samples containing between 5 and 15 micrograms and requires similar corrective action but allows schools to flush out affected fixtures as an interim fix.

Submitted to DEQ, approved flushing plans require schools to remove stagnant water from affected fixtures and plumbing infrastructure whenever a school becomes inactive for more than three days.

Lastly, “Bin 3” includes samples containing less than 5 micrograms and requires no corrective action for safe drinking water.

Overall, of 47 school drinking fountains tested in Lincoln County, 10 samples were found to have lead levels between 5 and 15 micrograms. Remaining samples were deemed safe.

The highest lead concentration found from sampled drinking fountains reached 15 micrograms.

Of 22 kitchen sinks tested, two samples contained lead levels between 5 and 15 micrograms, and two samples contained lead levels exceeding 15 micrograms.

The highest lead concentration found from sampled kitchen sinks reached 55 micrograms.

Of 124 bathroom sinks tested, 12 samples contained lead levels between 5 and 15 micrograms, and four samples exceeded 15 micrograms.

The highest lead concentration found from sampled bathroom sinks reached 26 micrograms.

Of 76 classroom sinks tested, 26 samples contained lead levels between 5 and 15 micrograms, and 11 samples contained lead levels exceeding 15 micrograms.

The highest lead concentration found in classroom sinks was 106 micrograms, or more than 700% of what’s allowed by the EPA in public drinking water.

Montgomery did not identify specific Lincoln County schools or facilities, but individual schools are required by the state to provide public sampling results.

Montgomery said sampling is obtained from the “first pull” of water from fixtures or plumbing on the day of testing, meaning samples come from water left stagnant in the infrastructure for at least six hours.

Stagnant water is generally expected to contain higher levels of lead, he said. Sampling it produces a “worst-case scenario” for lead contamination.

As more water is pulled during daily use, Montgomery said, drinking water infrastructure becomes flushed of lead contamination — typically, from past uses of lead soldering — and thereby safer to use throughout the day.

He cautioned that COVID-19 protocol and other issues causing lessening school water use could have helped cause elevated levels of lead in facilities.

Schools accredited with the Montana Department of Education were required to start the lead testing by January 17, 2020. Schools were then given until Dec. 31, 2021, to complete initial sampling.