By Stephanie Choate
Plans to clean up a plume of contamination beneath Commerce Street in Williston are moving forward this year.
Remedial Project Manager Karen Lumino of the Environmental Protection Agency met with approximately a dozen residents last Wednesday, who all braved the snow to catch up on cleanup progress at the Superfund site.
Residents will see action at the site this summer, including excavation of contaminated soil on one property, as well as the final, intensive stages of study for addressing contaminated groundwater.
Over a decade ago, the EPA identified a 70-acre plume of contamination. The groundwater beneath Commerce Street, South Brownell Road and Kirby Lane contains high levels of toxic compounds used to clean metals, including trichloroethylene and tetrachloroethylene. The EPA has also identified a small area of contaminated soil.
Quebec-based Mitec Technologies (then known as Mitec Telecom), was named as a source of contamination and paid a $120,000 settlement.
The area was named a federal Superfund site in 2005, and the EPA has been studying it since 2008. In September 2015, the EPA completed its Record of Decision for the site, outlining a remedy for cleaning up contamination.
The EPA considers the groundwater exposure risk to be “under control”—all homes and businesses in the area use municipal water, not groundwater. However, its goal is for groundwater to eventually be potable at the site.
EPA officials plan to excavate the small area of contaminated soil this summer, and hope to have excavation work completed by October.
“Groundwater (contamination) is quite extensive, but the soil (contamination) is confined,” Lumino said.
EPA officials have identified contaminated soil on part of one commercial parcel— 96 Commerce Street, the property formerly leased by Mitec.
Lumino said federal funds have been allotted for the soil cleanup work on the parcel —$400,000– — 10 percent of which is the state’s match.
She said EPA officials believe soil contamination is confined to the site of the former wastewater lagoon on the back of the property, but once workers begin excavating and removing the contaminated soil, they will know for sure.
“Once we get out there and do the excavation, we’ll be able to make sure we’ve gotten everything,” Lumino said. “If it turns out we didn’t quite get it all, we’ll have to move to neighboring properties, but we believe it’s confined to that property.”
Purifying the groundwater will be a longer, slower and more expensive process, however.
In September 2016, EPA awarded $993,610 to the Vermont Department of Environmental Conservation to develop a remedial design, fine-tuning the cost and specifics of the groundwater cleanup project.
In its 2015 plan, the EPA outlined a three-part approach to clean up the groundwater.
First, the agency will implement institutional controls to ensure that no one is allowed to use groundwater at the site—either through a town ordinance or deed restrictions.
“Nobody is using it now, but we need to make sure that continues in the future,” Lumino said.
It will treat the more contaminated areas of the plume by injecting reagents like hydrogen peroxide or ozone into the ground.
In the less contaminated sections, the agency will introduce naturally occurring microbes that eat the contaminants, speeding up Mother Nature’s remedy.
Under EPA’s supervision, the state will hire contractors to probe the cleanup methods more thoroughly. They will determine exactly what substances and microbes to utilize, exactly where to inject them and exactly how much it will cost.
“They see what will react best in the exact environment,” Lumino said. “The remedial design is very, very specific.”
Michael Smith, a hazardous site manager with the Vermont Department of Environmental Conservation, is heading up the remedial design work. He said the state received nine contract proposals for the work. It has selected one, but Smith could not say which one, since the contract has not yet been signed.
“As soon as we get the contract signed, we’ll start the work on the initial work plan,” Smith said.
Smith said in the spring, workers will begin the first stage of investigation, testing different technologies at the site itself.
“There has been a lot of work done in the site investigation, but we need more site-specific data,” he said.
Smith said the remedial design process can take at least a year, but he’s hoping for a speedier conclusion.
“It has to be done by 2018, and I’m hoping it can be done sooner,” Smith said. “We’ll do our best to get it done quickly.”
Once the remedial design is completed, any action will have to wait for federal funding, Lumino said.
“We get in the queue for money to actually clean it up,” she said.
For more information, contact Karen Lumino at 617-918-1348 or email@example.com.