The Bethpage Water District is building a $19.5 million water treatment facility on Motor Lane to treat the Bethpage toxic plume -- a mass of concentrated levels of volatile organic compounds heading toward drinking water wells.

The plume is coming from a manufacturing facility once operated by Northrop Grumman and the U.S. Navy. Contaminated water was first discovered in the 1940s.

Experts say the toxic plume is 4 miles long, nearly 2 miles wide and is moving southeast about 1 foot per day.

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Bethpage Water District Superintendent Mike Boufis says the state-of-the-art water treatment facility will remove chemicals in groundwater before they reach public wells.

Residents say they hope it will take care of the drinking water threat that's been plaguing the Bethpage area for decades.

"I just hope that if there was a problem with people getting sick or whatever the problem was, I hope that they get it solved," says Don Whiston.

The Navy is expected to contribute $15 million for the project. The upgraded facility is scheduled to be up and running by next year.