Then-President Joe Biden visited Milwaukee in October 2024 to announced a new rule requiring the replacement of all lead water pipes in the U.S. by 2037. On Wednesday, Attorney General Josh Kaul announced Wisconsin is joining nine other states and D.C. to defend the rule. (Oct. 8, 2024 screenshot/White House livestream)

Wisconsin has joined with nine other states and the District of Columbia to defend the federal lead and copper water rule that took effect Dec. 30, tightening standards for lead exposure and requiring water systems across the county to replace lead pipes by 2037.

The new rule, which then-President Joe Biden announced in Milwaukee in October, has been challenged by the American Water Works Association, a trade group for water and wastewater utilities.

The Wisconsin Department of Justice announced Wednesday the state was joining the legal effort to intervene in the lawsuit in support of the rule. Other states in the coalition are California, New York, Connecticut, Illinois, Maryland, Massachusetts, Minnesota, New Jersey and North Carolina, along with D.C.

“Reducing lead in our drinking water shouldn’t be controversial,” Attorney General Josh Kaul said. “This common-sense rule that helps protect people’s health should remain in place.”

Lead exposure has been identified as a health hazard, especially for children, and has been linked to premature birth, damage during brain development and learning disabilities, delayed physical development in children and cardiovascular and kidney problems in adults. No amount of lead in drinking water is safe, according to the U.S. Environmental Protection Agency.

On Tuesday, Gov. Tony Evers approved an emergency rule from the Wisconsin Department of Health Services (DHS) to lower the threshold for lead poisoning to 3.5 micrograms per deciliter. The change makes more children and families eligible for intervention to diagnose and treat lead poisoning.

Evers has announced plans to seek a $6.2 million increase for local health departments, some of that to address lead poisoning, in the 2025-27 state budget that he will release in February.