Restoration Advisory Board Addresses NWIRP Site ~ the Former Raytheon Naval Systems Lab

Persistent contamination at the former Naval Weapons Industrial Reserve Plant (NWIRP) on Hartwell Road will delay any federal plans to divest the parcel, according to officials at a public meeting reporting on cleanup efforts.

“We have been wanting to get rid of this since 2000,” said Maritza Montegross, Navy remedial project manager, at a virtual meeting of the NWIRP Restoration Advisory Board last week.

But before any divestiture, all cleanup measures must be “operating properly and successfully.” Although “all the remedies are in place and the site is being cleaned up, right now we can’t say that because of the emerging chemicals and TCE expansion.”

An ad hoc committee of the Select Board has been exploring possible uses for the acreage. The panel was formed in response to the rapid federal divestiture of the southern flank of the NWIRP, featuring a large hangar, at an auction in 2018.

Montegross, an environmental engineer at the Naval Facilities Engineering Command, said federal and state agencies will continue to work with the Navy on remediation. “We don’t just hand this thing over and forget about it.”

Montegross did most of the talking at last week’s meeting of the Restoration Advisory Board, which is defined as “a stakeholder group that meets to discuss environmental restoration at a specific property that is either currently or was formerly owned by Department of Defense, but where DoD oversees the environmental restoration process.”

The primary focus was on two contaminated locations where cleanup is ongoing. One is defined as site 3, a “chlorinated solvent groundwater plume.” There is also site 4, a “benzene, toluene, ethylbenzene, and xylenes groundwater plume.”

According to the Navy, the NWIRP was established in Bedford almost 70 years ago, with a mission to design, fabricate, and test prototype equipment for missile guidance and control systems. The facility was operated by Raytheon. After more than 45 years, the mission ended in 2000 and the facility was closed and has been unused since.

Contamination was initially confirmed in 1986, and eight years later the area was added to the National Priorities List, also known as the Superfund. The Navy and U.S. Environmental Protection Agency signed an agreement in February 2000 related to conducting investigations, and since that year the two active sites have been the focus.

Removal action began in 1997 with a continually operating groundwater extraction system.

Cleanup was originally targeted for completion in 2018, but contamination will continue for decades, Montegross said. Indeed, she said site 3, which was a loading dock area, will not be fully remedied until 2090. That’s due to the presence of the chemical TCE, of which “a couple of drops can contaminate an entire pool,” she said.

The toolbox features extraction, treatment (“enhanced biodegradation injection”), natural attenuation, land-use controls, monitoring, and five-year reviews (the next one is scheduled for 2024). The 2019 review resulted in revised projections, Montegross said, because “we had contamination that we didn’t expect.”

Montegross reported that the primary flow extends from the location to the northwest toward Elm Brook. Water is pumped from 23 extraction wells on the west side, delivering 14 gallons per minute and filtered through carbon. The process is supposed to contain the underground plume, but it also removes volatile organic compounds, Montegross reported.

Bedford Health and Human Services Director Heidi Porter asked if the effluent is being tested for the chemical substances known as PFAS. Montegross said that is being investigated but PFAS aren’t anticipated there.

Groundwater investigation around site 3 aims to determine the nature and extent of 1,4 dioxane and TCE to the north, east, and south. Montegross said additional monitoring wells are being installed in these areas. The flow used to be to the northwest, but now it is moving to the east, she said. A report isn’t expected until the end of next year.

Plans call for the design of an additional extraction system north of the site “to improve capture of 1,4 dioxane and TCE and pull back the eastward TCE expansion.” There will be additional wells built next year, she said. Additional cleanup technologies may need to be installed to address 1,4-dioxane and TCE.

Asked by a resident about the proximity of the plume to residential property, Montegross said it is still within the boundaries of federal property. She said probes cover not only the plume but also the potential for vapors rising from beneath the ground.

“Whenever we are dealing with TCE, we have to be concerned about vapor intrusion,” Montegross said. Any building erected on the site will have to be equipped with a system to detect vapors.

There is some contamination as well under the 16 acres south of Hartwell Road, now privately owned. Cleanup is supposed to be complete by 2028. Montegross said TCE has been detected on the southeast corner of the site, far from the hangar.

Another resident asked about the status of some 20 abandoned buildings on the site – structures that a few years ago the Navy wanted to demolish because they were accessible to trespassers. Montegross said the Navy has installed cameras connected to the Police Department, and there has not been any vandalism for several months. There are no plans to salvage any of the buildings.

Reports on environmental actions are available to the public through the Navy’s administrative record file for former NWIRP Bedford.  The file is available at

Mike Rosenberg can be reached at, or 781-983-1763

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