A class-action lawsuit accuses Northrop Grumman of knowingly exposing Bethpage residents to toxic chemicals.

Fifteen people are suing the company for $500 million. The suit alleges the company knew about toxic chemicals near its Bethpage site and never warned them.

"We filed the lawsuit because we believe Grumman has the responsibility in the community to tell residents what their exposure is and to measure their exposure," says attorney Paul Napoli.

In a statement to News 12, a spokesperson for the company said in part: "The allegations appear to be entirely without merit. Northrop Grumman continues, as it has for several decades...to address legacy environmental conditions and protect the residents in the Bethpage area."

The Bethpage Water District filed a lawsuit against Grumman three years ago claiming the way the company disposed of toxic chemicals contaminated groundwater. The district says that contamination cost it millions of dollars.