State blames commercial properties for slight increase in Flint water lead levels

Drinking water in the city of Flint remains within the federal Safe Drinking Water Act standards, the Michigan Department of Environment, Great Lakes and Energy announced Monday, although the levels identified in the latest round of testing were higher than the previous one.

The latest drinking water sampling results showed the city's 90th percentile result was 10 parts per billion, which means 90 percent of the test results were at or below 10 ppb. The federal action level is 15 parts per billion.

The August sampling results were 8 ppb.

The latest results are based on a six-month monitoring period from July 1 through Dec. 31. Thirty-one residences and 30 commercial properties were tested. Three had lead levels above the federal action level of 15 parts per billion.

Aging interior plumbing was the cause of the elevated levels at two of those three sites, EGLE said in a press release. Commercial properties often increase lead level results "because they often have lower water usage rates leading to stagnation of the water in the pipes where it picks up more lead over time," EGLE spokesperson Scott Dean said in an email.

Eric Oswald, director of EGLE's Drinking Water and Environmental Health Division, said the remaining challenge is "modernizing household plumbing and encouraging more regular water usage at businesses to drive these lead detections even lower."

The latest sampling results show ongoing challenges in Flint, the mid-Michigan city that was home to a drinking water crisis starting in 2014 because of high lead levels, said Elin Betanzo, founder of the Detroit drinking water consulting firm Safe Water Engineering.

The city is still waiting for all of its lead service lines to be replaced, Betanzo said in an email, and needs more corrosion control to mitigate lead in household plumbing.

"The work is not yet done in Flint," Betanzo said. "Residents continue to need reliable access to safe drinking water — 10 ppb of lead in the water is never okay to drink! It's time to get the lead service lines out once and for all."

More than 95% of Flint's residential sites have had their lead service lines replaced. EGLE's Dean said the city hopes to complete the service line replacements by May.

"Excavations and replacement efforts are on hold for the winter," Dean said. "The city already has the required access agreements in hand for some of the properties and is still seeking permission from other property owners."

The U.S. Environmental Protection Agency is pursuing a stronger Lead and Copper Rule that would require water systems to replace lead service lines within 10 years and lower the action level from 15 ppb to 10 ppb.

ckthompson@detroitnews.com