Officials in Newark, N.J. have shut off water fountains at 30 public schools due to elevated lead levels, but they say that — despite fears about lead stoked by the drinking-water crisis in Flint, Michigan — parents should not be concerned about the safety of their children.

City and school officials are planning to provide bottled water to schools until they can finish whatever remediation and re-testing is necessary to ensure that the problem is resolved.

“Ensuring the health and well-being of our students in the immediate days and weeks has been, and will continue to be the primary driver in our decision to bring drinking water into 30 schools,” Newark Public Schools said in a statement Thursday afternoon.

Newark shut off the water and posted notices at the 30 schools on Wednesday after annual testing found a range of lead levels, from undetected to above 15 parts per billion, a threshold at which the Environmental Protection Agency recommends taking action.

The school system is working with the Department of Environmental Protection to address the issue, including by creating a plan to sample all schools and buildings in the district. Officials also are working to ensure that families have free access to blood testing if they are concerned about their children’s lead levels and cannot afford testing through a primary care doctor.

About 35,000 students attend Newark’s 66 public schools, according to the school system’s website.

Officials emphasized that the risk in Newark appears far less significant than in Flint, where lead levels ranging from 27 parts per billion to 397 parts per billion have provoked national outrage.

“I understand in the Flint environment that any sign of elevation is going to make everyone go haywire, but here, the water system in Newark is still safe, it’s still drinkable,” Newark Mayor Ras Baraka said Wednesday, according to the Associated Press. “A lot of our buildings are old. That speaks to infrastructure, the reason why we need new schools.”

The Newark school system and the Department of Environmental Protection jointly announced Wednesday that lead has not been found within the city water source. The agencies emphasized in a statement that when lead is found in drinking water, it usually is due to leaching “from lead pipes, household fixtures containing lead or lead solder,” and that lead in drinking water alone is not usually to blame for elevated lead levels in blood.

“It is the buildup of lead from all sources over time that determines whether harmful health effects will occur,” the agencies said in their joint statement.

Newark schools have been under state control since 1995.

Newark Teacher Union president John Abeigon blamed state officials for seeking to expand charter schools “even if it means neglecting the safety of children and staff in the traditional public schools.”

He provided memo sent that Newark Public Schools sent to principals, custodians and others in 2014. It said schools were required to flush their water systems daily “to reduce the risk of possible lead contamination.” Custodians should run every water fountain for two minutes at the start of each day, the memo said, and students and staff should be instructed to run fountains for 30 seconds before drinking.

“Who allowed children to drink this water and for how long? This is a serious question that must be answered by federal authorities,” Abeigon said in a statement Thursday. “Lead levels are tested regularly and results shared with administrators who are trained to read and respond to the results. What happened here? Who received the results over the last several years and what did they do with them?”