NEW YORK (CBSNewYork) — First it was Valley Stream, then Commack, and now East Northport at the Dickinson Ave Elementary School where high levels of lead have been found in water fountains.

The district said the fountains were shut down after 12 were found to have unacceptable levels of lead.

The problem, experts said, was older buildings with older pipes.

Water suppliers are required to make sure the water is safe going into buildings, but schools are not mandated by law to test the water.

Other districts said law or no law they are planning to test the water in their schools.