Detroit officials say the city's water supply is okay, and that they think the problem stems with the schools' aging infrastructure.

The Flint Water Crisis occurred when the struggling former automobile manufacturing hub decided to switch its water source from Lake Huron to the highly corrosive Flint River. That eroded water mains, contaminating the city’s water supply and turning it brown. Now just over 70 miles away in Detroit, its public schools are having problems with their water.

Last Wednesday, less than a week until the start of the new academic year, the superintendent of the Detroit Public Schools Community District, Nikolai Vitti, said they were going to cut off the water supply in schools because of “elevated levels of copper and lead.” “While it is unclear how many of the district’s 106 schools currently have water quality issues,” Vitti said, “the drinking water will be turned off in all of them.”

The decision was made after higher levels came back in 16 of the 24 schools whose results have been examined; they are still awaiting the confirmed toxin rates for the rest of the locations. Earlier this year, independent of any federal, state or city requirement, Vitti began testing every single water supply across each public school in the district for suspicious levels—including water fountains and sinks.

According to the Associated Press, officials think the problem stems with the aging infrastructure and not the overall water supply. In 2016, The New York Times reported that the classrooms in the city had witnessed scenes of cockroaches and rats and that thanks to years of consistent under investments and lack of upgrades, the schools had reached a breaking point, with teachers striking over the appalling conditions.

The Detroit Water and Sewerage Department put out a statement two days ago, reminding residents that the city’s water supply hasn’t been impacted the same way. In the press release officials said that water treatment plant is tested every hour and that “the drinking water is of unquestionable quality.”