Michigan on Thursday began enforcing the nation’s strictest rules for lead in drinking water, a plan that eventually will result in replacing all 500,000 lead service pipes statewide following the contamination of Flint’s water supply.

The lead and copper rules will drop the “action level” for lead from 15 parts per billion, the federal limit, to 12 parts per billion in 2025. Underground lead service lines connecting water mains to houses and other buildings will be replaced by 2040, unless a utility can show regulators it will take longer under a broader plan to repair and replace its water infrastructure.

The rules also will prohibit the partial replacement of lead service pipes except for emergency repairs; require preliminary and final inventories of the lines and other components of a water supply by 2020 and 2025; and ensure samples are taken at the highest-risk sites and with methods designed to more accurately detect lead.

Additional changes are designed to verify that corrosion control is working and to better educate the public about lead in water.


The plan could cost $2.5 billion over decades, money that is expected to largely come from water customers.

“The federal lead and copper rule simply does not do enough to protect public health,” Gov. Rick Snyder said in a statement. “As a state, we could no longer afford to wait on needed changes at the federal level, so Michigan has stepped up to give our residents a smarter, safer rule — one that better safeguards water systems in all communities.”

Local governments and water utilities remain unhappy with the new rules, which were drafted and revised over a two-year period. They have called them a costly overreaction to the unique, man-made lead contamination in Flint that occurred when the city’s water source was switched in 2014 and not treated to prevent corrosion while Flint was under state management, enabling lead to leach from aging service lines and household fixtures.

Bonnifer Ballard, executive director of the American Water Works Assn.'s Michigan chapter, said utilities recognized the rules needed to be updated and improved and that lead pipes should be replaced. But a 12 parts per billion standard is “completely arbitrary,” she said, adding: “Where is the money going to come from? ... We’re just trying to figure out how in the world we’re going to get all this done.”


She said there is a provision in the lead rules that could force communities to accelerate their pipe replacements more quickly than a 20-year timeline, creating a “conundrum” because they will have to stop doing other important water infrastructure projects to stay in compliance.

Environmental groups are supportive, however, saying Michigan’s rules will set an example for other states and the Environmental Protection Agency, which has been considering changes to the federal regulations.