SOURCE:
https://www.newsday.com/long-island/environment/bethpage-grumman-navy-plume-uqubpufb
By Joseph Ostapiuk - August, 2025
The U.S. Navy is set to open a new treatment plant that is expected to help contain the extensive Grumman groundwater plume slowly moving south in Nassau County.
The Navy plant on Union Avenue, near Hempstead Turnpike in Bethpage, is expected to be operational in September, according to the state Department of Environmental Conservation.
Also, the DEC said the Navy had installed six treatment extraction wells alongside nearly 18,000 feet of piping inside the plume. Four of those six wells came online last year and are connected to two separate interim treatment systems. The temporary systems have been in use while the Union Avenue facility was under construction.
"Great strides have been made," Mike Boufis, superintendent of the Bethpage Water District, said in an interview. "The plan that's being moved forward with is working to remove the contamination."
With the new permanent system on Union Avenue up and running, the Navy will be able to use its interim treatment systems elsewhere to lower contamination levels when hot spots emerge, Boufis said.
The interim systems have traditional equipment, such as granulated activated carbon and an advanced oxidation processing systems. They are stored in structures that resemble cargo containers, Boufis said.
"Once that system gets online, they'll be able to move these temporary systems around to attack the hot spots," Boufis said.
More facilities underway
Below the southern edge of the plume, the Navy has three wells up and running and built an interim water treatment system that came online in June. The Navy is expected to start building a treatment plant near the Southern State Parkway in 2026, which will go online in 2027, the DEC said.
Groundwater sampling has not detected contamination above drinking water standards by the Southern State Parkway, according to the DEC.
"The additional groundwater extraction wells will absolutely assist in the quality and quantity of the cleanup," Adrienne Esposito, executive director of the Citizens Campaign for the Environment, said in an interview. The new Union Avenue treatment facility will "allow for so much more of the remediation to take place," she said.
The plume, more than four miles long and two miles wide, extends as far as 900 feet deep and threatens Long Island's aquifer that supplies drinking water to 3 million people.
It started from Grumman's 609-acre aircraft manufacturing facility in Bethpage, which operated from the 1940s until the 1990s. The aerospace company dumped hazardous waste, including known carcinogens, into the soil and was aware of the hazard as early as the 1970s but did not disclose it, a Newsday investigation found.
The DEC said in its statement that it's headed "toward a full containment of this groundwater plume to prevent the further spread of contamination to water supplies in neighboring communities."
No new drums found
At Bethpage Community Park, Northrop Grumman contractors completed an underground investigation in search of buried chemical drums. In March 2024, contractors unearthed 22 concrete-encased drums containing a toxic mix of chemicals.
The geophysical investigation focused on 16 areas within a section of the park's ballfield area where ground-penetrating and electromagnetic radar technology detected "anomalies," the DEC said. The metallic anomalies were mostly piping and cable, and nonmetallic anomalies were "trace debris," according to the DEC.
That investigation only covered a limited section of the park, Oyster Bay Supervisor Joseph Saladino said in a statement on Thursday.
"Only a small area (60 feet by 60 feet) of the former ballfield has been cleared of buried barrels so far," Saladino said. "Other anomalies identified by the geophysical scans across the 18 acres of the Park still remain to be investigated for buried drums."
