Editor’s note: This story by David Corriveau was published by the
Valley News on June 8.
[S]OUTH STRAFFORD — The cleanup of the former Elizabeth Mine resumed last week, starting what federal environmental officials hope is the final phase of remedial work that began 18 years ago and has cost almost $90 million.
“We’re almost there,” Ed Hathaway, longtime manager of the Superfund remediation work for the Environmental Protection Agency, said in a phone interview on Wednesday from the EPA’s regional office in Boston. “We’re closing in on finishing up this big, long project.”
The EPA declared the property a Superfund site in 2001, citing the acid- and metal-contaminated water that had been running through and leaching from waste rock and tailings into streams feeding the west branch of the Ompompanoosuc River since the 150-year-old copper mine closed in 1958.
Hathaway said South Strafford residents — and mine neighbors just over the town line in Thetford — can expect less truck traffic this summer than last, with none of the blasting that characterized much of the 2018 segment of the effort to prevent waste from further polluting the area, especially the Ompompanoosuc watershed. Work is expected to be finished by next summer.
Where trucks hauled almost 1,500 loads of material to the site in 2018, the EPA expects between 600 and 700 truck trips this summer to bring stone for ditches, topsoil for restoring surfaces and a small amount of limestone.
The main focus of the project now shifts to the dismantling of a wastewater processing plant that had been treating toxic leachate from the mine since 2008, and replacing the plant with what Hathaway describes as “a passive, gravity-based system that will use limestone and natural settling ponds” that Vermont environmental experts will maintain and monitor.
“It’s a big accomplishment,” Hathaway said. “We won’t have to haul in lime, repair pumps and check alarm systems. That’s a big shift.”
Strafford resident John Freitag, who served on the Selectboard for a number of years during the project, describes the treatment plant as one of several examples of the EPA’s willingness to respond “to legitimate concerns raised by community members by stepping up their game,” after initially misjudging structural and engineering problems at the site.
During an exchange of emails last week, Freitag praised the agency for pursuing the treatment plant after “work done at the site … exposed a good deal of material to air, sunlight and rain (that) turned the West Branch orange” in 2007.
EPA estimates that the former plant treated almost 51 million gallons of leachate, including 2.2 million gallons in 2018. During that time, water-quality monitors documented that the concentration of copper flowing from Copperas Brook into the Ompompanoosuc’s west branch fell 99%, while the concentration of iron dropped 95%.
Along the way, state and environmental officials removed the Ompompanoosuc from the list of waterways too “impaired” to support aquatic life.
Among the early priorities of the project was stabilizing, in 2005, a long-standing dam that held back tailings from the mine, Freitag recalled. Six years after completion of that work in 2005, Tropical Storm Irene tested the dam as never before.
“It held up fine,” Hathaway said. “We had relatively minor erosion around the site. I recall driving up there afterward and looking at the devastation all around.
“Many of us on the project team were very relieved.”
In addition to rehabilitating 46 acres at the site, the EPA commissioned the 2017 installation of 20,000 solar panels — the largest such array in Vermont. Energy consultant Dori Wolfe, a Strafford resident, championed the project, into which several investors sank $18 million. According to New York City-based Greenwood Energy, which manages the array, the 5-megawatt installation now powers 1,200 homes a year, while offsetting 6,000 tons of carbon dioxide, the equivalent of emissions from the burning of 14,000 barrels of oil.
“We are very proud of this project,” Mazen Turk, Greenwood’s director of asset management, said last week. “We often include it in our social-media outreach.”
This summer’s remaining cleanup work around the dam will include spreading soil over sites filled with mine waste, repairing surrounding roads and securing horizontal tunnels so they won’t collapse, according to Hathaway.
“The really big hauling work is pretty much done,” he said. “If all goes well, we’re hoping to wrap up the site next year.”
Hathaway estimated that this year’s work will cost about $6 million, likely pushing the cost of the project past $90 million.
“That’s a lot,” Hathaway acknowledged, “but it’s not nearly at the scale of projects like this out west.”
Once the Elizabeth Mine is done, the regional EPA will turn its attention to two other abandoned copper mines in Orange County — the Ely in Vershire and Pike Hill in Corinth.
“They’re both smaller than the Elizabeth, but the fundamental mechanism is the same at all three. The brooks around them are effectively dead,” Hathaway said. “We hope these cleanups will be less expensive.”
To learn more about the Elizabeth Mine clean-up project, visit http://epa.gov/superfund/elizmine.
