A key player in a plan to clean up a toxic underground plume in Bethpage that is contaminating the groundwater says it's not on board with the mop-up.

Mike Boufis heads up the Bethpage Water District in the epicenter of Long Island's largest groundwater plume of toxic chemicals. The contamination is linked to the former Northrop Grumman and Navy facility in Bethpage.

"It has the potential to impact hundreds of thousands of residents," says Boufis.

That is why Boufis and other water districts in the plume’s direct path are fuming over the U.S. Navy's recent refusal to pay for a $585 million plan by New York state to clean up Long Island’s sole source aquifer.

“We never really expected them to step up and admit that this is their responsibility and sign on to the plan,” says Boufis. “ We were hoping they would do that only because the community has suffered long enough.”

The Navy claims the state's remediation plan is not based on science.  In August, Northrop Grumman requested the state's cleanup proposal be withdrawn, calling it "unnecessary, infeasible and impractical."

Boufis says while the polluters stall the cleanup effort, the water in his district is being cleaned by high-tech and costly filtration systems

The Bethpage Water District tests its water every single day.  Boufis says they take 70% more samples than are required by law.

Boufis says it is imperative the toxic plume is cleaned up and stopped before it impacts other water districts. If not, he says it will eventually reach the Great South Bay.

Gov. Andrew Cuomo has warned if the Navy and Northrop Grumman refuse to take part in the cleanup plan, the state will implement the remediation and then force the polluters to pay back New York state.