The pipes are not connected directly to the city’s water system, but they do provide a crucial link to it.
They are often used to carry water from the taps to the tap water treatment plants and are also a source of water to nearby homes.
The pipes carry about 90 percent of the water in Flint, a city of roughly 9,000 people in northern Michigan.
But because they were replaced in the city after the switch from Lake Huron water to Flint River water in 2014, those pipes are also now at risk of leaking.
The city of Flint has since started replacing the pipes with corrosion-resistant ones, but the water supply remains shut down.
It’s not yet clear when that will happen.
In April, the Michigan Department of Environmental Quality said it was closing the Flint River to drinking water for more than two weeks because of lead contamination.
The agency said that because the water was treated in Flint’s Treatment Plant No. 4, it posed a “higher than expected risk of lead-contamination.”
The city has since switched back to Lake Hurons water.
The EPA has since been ordered to investigate the city.