Less than a week before classes are scheduled to resume, Detroit’s city school district announced Wednesday that drinking water will be shut off for all its schools because of concerns over above-normal levels of lead and copper.

The decision comes after tests of various water sources at 16 out of 24 schools showed elevated amounts of the potentially toxic heavy metals, according to a statement from Detroit Public Schools Community District Superintendent Nikolai Vitti to local media. With the goal of ensuring the safety of students and employees, Vitti said he began testing everything from sinks to water fountains at all 106 of the district’s schools last year, the Detroit Free Press reported.

“Although we have no evidence that there are elevated levels of copper or lead in our other schools where we are awaiting test results, out of an abundance of caution and concern for the safety of our students and employees, I am turning off all drinking water in our schools until a deeper and broader analysis can be conducted to determine the long-term solutions for all schools,” Vitti said in the statement.

On Tuesday, water at the 16 schools was shut off and bottled water was being provided until water coolers can arrive, Vitti said, according to the Free Press. The district now has 34 total schools with contaminated water in the district, as 18 other schools already had their water shut off.

The remaining schools will have their water turned off this week, Vitti said, according to Detroit News. Staff and families were made aware of the decision Tuesday via automated phone calls, Detroit News reported.

Mia Jones, whose child attends Cass Technical High School, one of the schools affected, told WJBK that the situation should have been handled before it got this bad.

“These are high-achieving students, and not just because this is Cass, all Detroit public schools,” Jones said. “They deserve to be able to drink the water.”

Water quality has been an ongoing challenge for cities in Michigan, becoming the focus of national attention in 2014 with the Flint water crisis. In Flint, Mich., thousands were exposed to water that had high levels of lead and other pollutants.

Even small amounts of lead can cause serious health problems, and children under the age of 6 are especially vulnerable, according to the Mayo Clinic. Beyond learning and behavior problems, lead exposure can impact physical development, and in some cases, be fatal.

Drinking water with high levels of copper can also have adverse health consequences, including vomiting, diarrhea, stomach cramps and nausea. Copper toxicity has been associated with liver and kidney failure.

“I haven’t made this decision based on the Flint situation,” Vitti told WJBK. “I’m making this decision because I feel like it’s the best decision for children.”

Water professionals said the issue in Detroit schools isn’t the water per se but aging school infrastructure, namely old plumbing. Lead and copper can enter drinking water when service pipes containing the metals corrode, according to the Environmental Protection Agency.

In a joint statement, the Great Lakes Water Authority and the Detroit Water and Sewerage Department assured residents and customers in the area that “they are not affected by the lead and copper issues that the Detroit Public Schools Community District (DPSCD) is experiencing.”

The statement touted the hourly testing of water at treatment plants and noted that water distributed to any school district building does not go through “lead service lines.”

“The drinking water is of unquestionable quality,” the statement said.

Chrystal Wilson, a school district spokeswoman, told Detroit News that Vitti had asked Mayor Mike Duggan and Michigan Gov. Rick Snyder on Wednesday to convene a special task force to solve the water quality issue.

Until it is determined that the water is safe for drinking, schools will be provided with bottled water from the Great Lakes Water Authority, Detroit News reported. The school district serves more than 47,000 students, according to its website.

“The water will be turned off in all the schools until we find a solution for all schools,” Wilson said.

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