Officials say four water fountains at a Valley Stream elementary school have been shut off due to lead contamination. 

The district says the fountains will be replaced and additional testing is being done on other fountains.

The school district says four of the fountains at Wheeler Avenue School exceed federal lead standards. One had nearly twice as much lead as allowed. Lead can cause learning disabilities and brain damage.

Fountains that haven't been tested are also out of service as a precaution. 

After the superintendent sent a letter informing parents of the incidents, environmental advocates called for more schools to test drinking water.

Water suppliers are required to test and treat water before it enters a school, but there is no law requiring that schools test the water at the fountains, says Maureen Dolan Murphy, of the Citizens Campaign for the Environment.

"New York City has a model plan," Murphy says. "They've been aggressively replacing lead pipes and plumbing at schools and requiring mandatory testing. If New York City can do it, we can do it here on Long Island."

There's currently a bill in the state Senate that would require schools test for lead at the fountains. United States Sen. Charles Schumer has also proposed a $20 million federal grant program to help districts pay for testing.