As the Biden administration makes billions of dollars available to remove millions of dangerous lead pipes that can contaminate drinking water and damage brain development in children, some states are turning down funds.

Washington, Oregon, Maine and Alaska declined all or most of their federal funds in the first of five years that the mix of grants and loans is available, The Associated Press found. Some states are less prepared to pay for lead removal projects because, in many cases, the lead must first be found, experts said. And communities are hesitant to take out loans to search for their lead pipes.

States shouldn’t “shrug their shoulders” and pass up funds, said Erik Olson, a health and food expert at the environmental group Natural Resources Defense Council. “It’s troubling that a state would decide to take a complete pass on the funding because part of the reason for the funding is to figure out whether you even have lead,” Olson said.

The Biden administration wants to remove all 9.2 million lead pipes carrying water to U.S. homes. Lead can lower IQ and create behavioral problems in children. The 2021 infrastructure law provides $15 billion to find and replace them. That money will help a lot, but it isn’t enough to get all the toxic pipes out of the ground. State programs distribute the federal funds to utilities.

The Environmental Protection Agency said it is reviewing state requests to decline funds but did not provide a full list of states that have said no so far. That information will be available in October, officials said. States that declined first-year funds can still accept them during the remaining four years.

“EPA has been working closely with our state partners on utilizing Bipartisan Infrastructure Law funding that is available,” the agency said. Lead pipes are far more common in some states such as Michigan and Illinois, which each have hundreds of thousands. The harm there is clear. Flint’s lead crisis elevated lead in tap water to a national health issue. Residents of Benton Harbor, Michigan, drank water with too much lead for years until all their lead pipes were replaced. In response, however, Michigan is clamoring for as much money as it can get to remove lead.

The states that declined funds have fewer problematic pipes, but that doesn’t mean lead isn’t an issue. There’s concern about lead in some Maine schools. Portland, Oregon, has struggled with high lead levels for years, although recent tests have been better and officials say the issue isn’t lead pipes, but household plumbing.