HANSON — Town officials are looking for some influence in the final cleanup phase involved in removing munitions pollutants from the watershed and ponds around the former National Fireworks site in Hanover.
Hanson’s Select Board met jointly with the Board of Health and the Conservation Commission on Tuesday, May 17 to hear an overview of the plan for the ponds and streams on the property, which borders part of the town in the area of Winter and King streets.
“There are some new developments,” Town Administrator Lisa Green, saying that prompted her to invite the company to brief town officials.
While Hanover is “leading the charge” on the project, Select Board member Laura FitzGerald-Kemmett said.
“We have a piece of it in Hanson and we thought we needed to have a little bit more of a voice — or, at least, a voice — in what was happening,” she said, noting at least four board members wrote in during the remediation plan’s public comment period for Phase 3. She asked if the towns were being consulted on remediation plans before they proceeded with the “full-on cleanup.”
“Because none of the people responsible own any of this property, the preference was [to] get rid of it and take it away,” said Ronald Marnicio, Tetra Tech’s national discipline lead for risk assessment. “When you get to that point, there’s not too many other choices.”
The company Tetra Tech, a global consulting and engineering firm that helps clients address water, environment, infrastructure, resource management, energy and international development challenges based in Pasadena, Calif., is cleaning up munitions at the site. The munitions response is scheduled through 2024, while that is being done the design is being completed and permitting will take about a year, so the first digging would likely not happen until 2025 or after.
Select Board member Kenny Mitchell asked what the area would look like in five to 10 years.
“It’s up to you guys,” Marnicio said. “It should be clean and useable for just about anything.” Hanover would remain classified as recreational land, but most of the land in Hanson is private property.
“In Hanson, it might look pretty much like it’s looking right now,” he said.
Conservation Commission Chairman Phil Clemons said he would like the work approached less like a regular engineering project and more like the “visionary, large-picture, long-term fix that it ought to be” and that no one would regret.
Marnicio said Phase 3 of the cleanup, what is being called the “final remedy,” is addressing chemical contamination in most of the ponds and streams on the property in both Hanover and Hanson. Most of the work is being done in Hanover.
“When the facility closed, it was quite apparent that there was a lot of burial and dumping down there,” Marnicio said.
Most of the contamination has been found in Hanover. Hanson’s land is located at the bottom third of the fireworks site around what is known as Factory Pond, was used as a test site and disposal area when the fireworks factory was in operation.
The site is being cleaned up under the Mass. Contingency Plan, which according to Marnicio, is not quite like the federal Superfund program. MCP is voluntary program.
Site assessment has been going on for “quite a few years,” partly because of the size of the site and the impact on soil, sediment and groundwater.
“Originally, our clients [owners of the fireworks property] were paying for all of this, so it was phased to keep the ball moving,” Marnicio said. “But it took a few years to get the whole thing characterized in terms of what was out there and what do you have to do to clean it up.”
The second phase of the MCP process in 2019-2020, drew up options for cleanup efforts and evaluation. In June 2021, the Mass. Department of Environmental Protection approved the remedial action plan, laying out requirements of the cleanup, including how much sediment would have to come out and acceptable levels that could remain.
Because none of the responsible parties own the property
“One of the things that has changed over the last couple of years is the magnitude of the munitions response,” Marnicio said. “[It] has to be completed before the cleanup of the sediment in the ponds.”
The discovery of additional munitions has extended the phase before the final remedy.
That was FitzGerald-Kemmett’s concern.
“We’ve been pulling things out of there since 2017,” Marnicio said. “These numbers are really kind of staggering — 18,300 items were explosive and were removed and exploded by the Mass. State Police Bomb Squad.”
There was also a lot of inert material, which resembled munition, but would not detonate. Still, Marnicio said it was “not a good thing to have in a public property.” More than 10,000 tons of contaminated soil has been shipped off the site. The cleanup in the upper portion of the property is about 75 percent done.
“We believe when the place closed down, they bulldozed a lot of things into [Factory] pond,” he said, noting that a copper dam will be installed on the outside of an upper area of the pond to bring water level down and remove contaminants in dry conditions.
Final remedy is designed to remove mercury and lead from the sediment in ponds. Estimated cost of Phase 3 is between $64.7 and $95.1 million. State figures the cost as being between $72.6 and $106.5 million.
“This is not going to cost the taxpayers in either town any money, I’m assuming,” FitzGerald-Kemmett said. “And I’m assuming … ‘the potentially responsible parties’ will be paying, or who will be footing the bill for this massive cleanup?”
Marnicio said the potentially responsible parties were paying for it, the trust fund set up when one party went bankrupt has been paying for all the munitions response work and some of the characterization work.
MassDEP and the Department of Defense have been working on a consent decree to figure out who pays after the trust is depleted.
FitzGerald-Kemmett said the town does not have the money to do so and did not contribute to the problem, and should not be expected to pay any costs.
“After we dig, there’s always been the question of to what degree do we need to put material back in,” Marnicio said. “Do we need to restore wetlands?”
Exposing material that had been underwater also triggers more regulation and they have to work with private citizens who own property along the Hanson portion of the property.
“I am really shocked at the thought of draining such an important little ecosystem,” FitzGerald-Kemmett said. “We all know restoration, once those things go backwards, it’s hard to restore them … only time does that, with the right conditions.”
Marincio said most of the area has contamination within the top six inches of the sediment.
She asked what would happen if a resident did not give permission for remediation on their property.
“I honestly don’t know how that would be handled,” Marnicio said.
Health Agent Gil Amado noted that everything has to be approved by DEP.
“The balance is you destroy it to save it,” Marnicio said. “There are requirements to re-establish wetlands and there are multiple-year monitoring that the restoration requires. It is risky, but that’s part of the plan, to put things back.”
He said groundwater was something that’s been measured since the ’90s.
“Fortunately, groundwater has not been a concern,” Marnicio said.
FitzGerald-Kemmett also spoke to the groundwater contamination and long-range health concerns residents have been speaking about and posting on social media.
“That kind of problem depends on your exposure over time,” he said. “I don’t think there’s been an increase in contamination.”
As they do the munitions removal they are cleaning soil cleanup goals for the final remedy, Marnicio said.
He also spoke to Select Board concerns about air-quality during the soil and sediment removal.
“What we’re most watching is particulates,” Marnicio said, noting that wind-direction is constantly monitored to make sure they are not going off-site. Work is stopped with air quality monitors sound alarms.
“Truck traffic on-site when it’s very dry will beep,” he said. “We determine what the cause is, [and] if we can determine that cause right away we can try to fix it or use water sprays.”
While it’s never happened yet, if the cause can’t be found, work will stop until it is found and addressed.
“There needs to be some robust communication,” FitzGerald-Kemmett said. Marincio said Hanover’s website tracks needed information and makes it available to residents.
Select Board Chair Matt Dyer said he would prefer 24-hour monitoring of the ponds to the continuous monitoring being planned once digging begins.
During the second year of the work the wetlands will be allowed to fill back up and close the dam down. Hanson areas are relatively shallow with a limited amount of sediment needed to be removed.