The federal government says New York's Westchester County is not properly treating some of its drinking water.
In a civil lawsuit filed Tuesday, the government says a parasite that can cause disease could be getting through.
Areas involved include White Plains and Scarsdale.
The lawsuit says Westchester is violating the Safe Drinking Water Act by not using a specific treatment for the parasite.
A county spokesman said Westchester has been working with federal officials and has come up with a remedy but could not meet a deadline. He says the water is safe.
The lawsuit seeks a permanent injunction and fines of up to $37,500 a day.