A former LILCO manufactured gas plant in Hempstead is the second-most contaminated site in New York State, and residents wondered Wednesday why it hasn't been cleaned up.

A report prepared for KeySpan, the current owner of the property, states a 4,000-foot plume of pollutants lies beneath the plant, which closed 50 years ago. The report warns the toxins pose potential human health hazards. The pollution runs from Hamilton Place and Hilton Avenue south beyond Fulton Street.

Dr. Joe Como, an oral surgeon whose office has sat above the contaminated area for 10 years, said he just found out a few days ago.

"These are carcinogenic materials," Como said. "These are not the type of materials you want to be drinking."

The state Department of Environmental Conservation has scheduled a public hearing at Adelphi University about a proposed cleanup. That meeting will take place Thursday at 7 p.m. However, critics complained few residents were aware of the meeting.

Some believe the DEC and Nassau County Department of Health have known about the pollutants for seven years and are just now taking action.

Adrienne Esposito, of the Citizen's Campaign for the Environment, said, "the DEC has been extremely lax in implementing any kind of a cleanup plan and public health protection. And, frankly, Nassau County Health Department hasn't been pushing it either."

The DEC said it has investigated the plume and found no danger to drinking water. It denies it has taken a lackadaisical approach to the problem. Nassau's Health Department said it wasn't asked to participate in the investigation.