The smell of fresh concrete still hung in the air when officials gathered on Union Avenue in Bethpage last week to mark something residents here have been waiting decades for.
On March 31, the U.S. Navy cut the ribbon on its new $46 million groundwater treatment facility at the former Northrop Grumman site, the latest chapter in one of Long Island’s longest-running environmental cleanup battles. The Phase II Groundwater Treatment Plant, built to tackle a toxic plume that has shadowed Nassau County communities for generations, is now back in full swing after a brief suspension last December.
Not a small deal.
The facility began partial operations last fall, but service went dark in December, according to the state Department of Environmental Conservation. It’s been running again for over two months, and officials expect it to hit full capacity sometime this summer.
The numbers behind the plume are staggering. More than 4 miles long, 2 miles wide, and reaching depths of 900 feet beneath Nassau County, the contamination carries chemicals including trichloroethylene and 1,4-dioxane. Long Island draws its drinking water almost entirely from a sole-source aquifer, a single underground reservoir with no real backup. Nearly 3 million people depend on it. The fear, shared by residents, local officials, and environmental advocates for years, is that the plume creeps ever southward through that aquifer, and cleanup has never quite kept pace.
Construction of the Phase II plant started in 2021. The new system is designed to extract and treat up to 3 million gallons of groundwater per day, pulling from six deep recovery wells before processing the water through multiple treatment steps to strip out contaminants. Cleaned water then goes back into the aquifer.
“Removing the remaining contamination will take many years because groundwater moves slowly deep underground,” said David Brayack, a project manager involved in the effort.
Still, the Navy says the numbers are moving in the right direction. Over 97% of the contaminated plume is now under active control, and more than 20% of the total pollution has been removed since cleanup began more than 25 years ago. The first phase used several wells to target hot spots. Phase II expands that reach farther south, chasing the plume as it migrates.
The history of how this mess got started is grim and familiar to anyone who grew up around Bethpage. Aircraft production at the former Naval Weapons Industrial Reserve Plant began in the 1940s. Northrop Grumman, which built fighter jets and spacecraft at the site, used the property as a chemical waste dumping ground before donating it to the Town of Oyster Bay in the 1960s. Parts of Bethpage Community Park, which sits atop what was essentially a chemical waste site, have been closed to the public since the early 2000s when toxic leaks were confirmed.
The state Department of Environmental Conservation approved a review of the Phase I work plan for cleanup of the former Northrop Grumman settling ponds at present-day Bethpage Community Park in March 2025.
“This milestone reflects decades of sustained effort, scientific rigor and partnership with the Bethpage community,” said Karnig Ohannessian, the deputy assistant secretary of the Navy for environment and mission readiness.
The ribbon-cutting brought a measure of momentum to a cleanup that has frustrated residents for years. But no one at the ceremony was calling it finished. The Navy is already planning a third phase of the project, though details on scope and cost haven’t been fully released yet.
The thing is, for families in Bethpage and the surrounding communities, a ceremony and a set of promising statistics can only go so far. Parents worry about what’s in their tap water. Homeowners near the park have watched property values carry the weight of a contamination story that keeps stretching on. The Bethpage Water District has spent years installing and upgrading treatment systems of its own to keep pace with what the aquifer carries.
Reporting from Long Island Press first detailed the facility’s launch and the timeline ahead.
More phases, more years, more wells. The plume didn’t appear overnight, and it won’t disappear that way either. But on a Tuesday morning at the end of March, at least there was something to celebrate. Three million gallons of groundwater a day, being pulled up, cleaned out, and sent back down. A slow fix for a slow-moving problem, working its way through 900 feet of ground beneath Nassau County.