The DEC is investigating a new possible case of illegal dumping on Long Island.

The agency says the site is on Furrows Road in Holtsville, and that it is investigating approximately 13 sites on Long Island.

In a statement to News 12, town officials say that they had observed what they called questionable activities at the site so they say they immediately told the DEC about it. The town says it will not comment further because of the ongoing investigation.

Environmentalists have dubbed illegal dumping as Long Island's "dirty little secret."

"Unfortunately, this isn't surprising, but it is scary," says Adrienne Esposito, of the Citizens Campaign for the Environment. "These are known toxic chemicals that come from typical construction debris from New York City. Typically, they contain asbestos, heavy metals such as mercury, banned pesticides ... and they end up all over long Island."

This investigation follows illegal dumping and cleanup efforts at Roberto Clemente Park in Brentwood.