BRUNSWICK, Maine — From 1981-2004, the U.S. Navy used an area called “Site 12” at the Brunswick Naval Air Station for the open-air detonation of small amounts of ordnance.
Now, some are saying the site is safe to use for recreation.
The Navy presented its case on Wednesday at a two-hour public meeting and information session at the Best Western on Gurnet Road.
Since 2007, the Navy has been assessing and removing munitions and explosives from the area, according to project manager Todd Bober.
The base was been declared a U.S. Environmental Protection Agency Superfund site in the late 1980s, requiring the Navy to design plans and clean up contamination areas on the property.
Site 12 is an approximately 23-acre parcel in the southeast portion of the former base. The central area used to consist of semi-circular earthen berms that contained the detonations.
The majority of the clean-up focused on excavating the two-acre site around those berms to a depth of 2 feet, and identifying and removing any live explosive material.
The berms were completely removed, and contractors also did an entire clearing of munitions items across the ground surface.
“It’s a clean site,” Robert Hielhozer of USA Environmental, the munitions response service tasked with clearing the area, said Wednesday. “Clean as it can be.”
Hielhozer said his team used geophysical mapping – essentially a cross between a high-powered metal detector and GPS – to detect explosives and leftover munitions.
In clearing the berms, the contracting team only found one item of live explosive, he said: a small blast cap.
In a nearby pond, USA Environmental found a few live pencil flares, which they detonated on site.
Other munitions items found included 20mm projectiles, 40mm smoke grenade casings and various fuses.
The team also found one large torpedo, but it was empty; most likely used for a training exercise, Hielhozer said.
“The most exciting things were dummy munitions,” said Chris Evans, a geologist with the state Department of Environmental Protection, who worked on the site.
The other concern on the site was the risk of possible chemical contamination from explosives.
Portland-based Tetra Tech did soil, groundwater, pond sediment and surface water sampling to determine the presence of hazardous chemicals.
Multiple analyses found “no unacceptable risks associated with residual contamination,” according to Navy documents.
Bober said the Navy has spent $3-4 million on site clean-up since it began in 2007.
Now, the Navy is ready to allow public use on the site, and eventually transfer the property to the town.
The preferred plan for assuring future safety on the site is through implementing land-use controls, Bober said, limiting future use of the site to non-intrusive, passive outdoor recreation like hiking, jogging, bird watching and hunting.
Anything that would qualify as “intrusive” activity, like industrial or agricultural uses, will be prohibited.
The Navy will leave up fencing, post warning signs, implement a public education program, and conduct annual inspections of the ground surface to monitor erosion and disturbance.
Just in case, the Navy also installed an orange tarp under the excavated berm area to limit anyone digging deeper than what’s been cleaned.
Bober said that because they found so few live munitions during cleanup, the risk for any more explosives in the subsurface is very low.
He said the cost for a “complete removal” – full excavation of all soils on the site down to the native soil, bedrock, or groundwater – would be more than $13.5 million.
The land use controls would only cost about $38,000 up front.
Bober contended complete removal would be a lot more money for a very little reduction in risk.
“We truck all over the site, we have heavy machinery all over the site … to us it seems very low risk,” he said.
“I’d go dig there anytime myself,” Hielhozer added.
Of the more than a dozen people at the public information session, everyone seemed satisfied with the controls presented, and nobody asked questions during the official transcript period.
The Navy’s land-use control plans have been endorsed by the EPA and DEP.
All three will sign a “record of decision” on the controls at the end of September, after incorporating written public comment.
Comments can be submitted to Bober at the Base Realignment and Closure program until Aug. 7.