BAY SHORE - The state Department of Environmental Conservation (DEC) has found high levels of toxins in the basement of a Bay Shore home near an underground toxic plume.

An old LILCO fuel processing plant left potentially cancer-causing contaminants in the groundwater. National Grid and the DEC have been cleaning up the site and testing the water for years.

Now, more than 70 residents are suing National Grid. According to a law firm representing the homeowners, the discovery contradicts the state's claim that residents are not in danger of being exposed to the toxins.

Residents involved in the suit are asking National Grid and the DEC to tell them whether the water is safe.

A spokesperson from the DEC says the problem appears to be localized, based on inspections of neighboring properties. Officials say laboratory results of samples taken during the inspection are pending.