The Michigan Department of Environment, Great Lakes, and Energy (EGLE) today announced that the City of Flint’s Lead and Copper Rule (LCR) monitoring has shown the 90th percentile for lead to be 1 part per billion (ppb).
This is a dramatic decrease from previous monitoring periods, and the City of Flint wants to help Flint residents understand what this means for our water quality. Compared to previous sampling periods that included more business locations, the current sampling result of 1 ppb more accurately reflects the water quality in Flint homes where water is regularly used.
“No amount of lead in water is safe, but this result demonstrates the effectiveness of our water system’s corrosion control measures, especially for residential homes where water is consistently used,” Flint Mayor Sheldon Neeley said. “My hope is that residents can take this opportunity to look at the science behind this result and better understand how the regular flow of water through our homes actually improves our water quality.”
The City of Flint adds orthophosphate to the water to prevent pipe corrosion and keep lead and other metals from entering drinking water. The State-mandated LCR monitoring is designed to show how well these corrosion control measures are working.
Corrosion control works best when water is flowing through pipes every day, so that they are coated with orthophosphates. When water sits still in a lead pipe, the corrosion control chemicals are not as effective, and lead has more opportunity to leach into the water.
In most homes where a lot of water is consistently used for bathing, laundry, and washing dishes, corrosion control tends to be more effective. Most businesses do not use as much water as homes and the water in businesses is often stagnant for long periods of time.
In previous sampling periods, the City of Flint was replacing lead service lines as quickly as they could be found, so there were not many known residential lead service lines available for testing. So, the City had to test more business locations that were known to have lead service lines. As expected, lower water usage at those locations resulted in higher lead levels.
However, in Fall 2023, the City completed about 1,000 investigative excavations and was able to identify over 200 residential lead service lines. The City is partnering with the State of Michigan to fund and complete these replacements, but in the meantime, the City was able to conduct testing at many of these homes this summer. That’s why Flint’s current 90th percentile for lead of 1 ppb more accurately reflects the water quality in Flint homes with normal water usage.
The City of Flint encourages Flint residents to pick up free water testing kits and water filters at Flint City Hall or the City of Flint Service Center on Clio Rd. No amount of lead in water is safe, and lead levels can vary from faucet to faucet because of factors like lead in household plumbing and differences in water usage.
For more information and resources, visit the State of Michigan’s Lead and Copper Rule website.
The City of Flint has completed 29,777 water service line excavations and identifications, including 10,529 lead service line replacements. The remaining lines were copper and did not need to be replaced.
Lawn and road restoration at about 1,800 residential locations is in progress this summer through a partnership between the City of Flint and the State of Michigan.
