Hundreds of schools across New York, including dozens on Long Island, have to take old water fountains and taps out of commission.

That's because a report says required lead testing shows more than one-third of buildings exceeded the state's newly lowered limit.

CBS News New York has learned what's behind the numbers and what districts have to do next.

What the state report shows

For nearly a decade, all school districts in New York have had to test their water for lead, but in 2023, the state lowered the allowable limit from 15 parts per billion to just five. That lower threshold means routine testing is now flagging thousands of fixtures that used to be considered safe.

According to the report, 34% of school buildings -- 1,642 -- exceeded the limit statewide. That includes 308 on Long Island, or 44% of buildings.

State health officials say the results are "not unique to any one district but a common finding during proactive testing required."

When levels go over the limit, districts must notify staff and parents and immediately take the fixtures out of service.

"[Lead] can cause brain and nervous [system] damage, lower IQ, so we want to make sure we are protecting our children," said Maureen Murphy, of the Citizens Campaign for the Environment, which advocates for safe water.

Murphy said the report is not shocking.

"Schools are old and they have old infrastructure, and that can include lead pipe joints. Between the pipes can be lead solder," Murphy said.

"We are going to take a really aggressive approach"  

The future of drinking water in many public schools will be filtered bottle-filling stations, replacing aging water fountains.

In the Farmingdale School District on Long Island, all of the old faucets and fountains are being taken out of service.

"We are going to take a really aggressive approach to improve the system we have in our schools. The best way to go about this is to turn off all of our drinking water stations," Superintendent Paul Defendini said.

Parents said they are not taking any chances.

"We give them water bottles," one said.

"They know not to drink the water," another added.

Schools that shut down water fountains are required to provide alternative drinking water for students at no cost, but parents can also send children to school with a filled stainless-steel water bottles.