PORTLAND, Maine — An engineering firm is drawing up options to clean up a site in Maine where decades ago a chemical-processing plant dumped tons of mercury into the Penobscot River.
The state’s highest court ruled in 2014 that Mallinckrodt US LLC must pay for cleanup at the site of the long-closed HoltraChem Manufacturing Company plant. Mallinckrodt is the last vestige of the plant’s former owners.
The contamination has meant closing part of the lower Penobscot River to lobster fishing, an industry that had gone on in the area for centuries. Maine People’s Alliance and the Natural Resources Defense Council sued in federal court to force the cleanup.
London-based engineering firm Amec Foster Wheeler is drawing up options for how the site could be cleaned up, and company spokeswoman Mary Kelley said the recommendations must be submitted by March. The options could include capping the area, dredging or potentially doing nothing, said Mark Robinson, a spokesman for Mallinckrodt.
But Robinson said the recommendations will signal a path forward to mitigation.
“It’s going according to plan. It’s a long and complex process,” Robinson said. “There could be a variety of solutions, and the court will make the decision from there on how to proceed.”
The HoltraChem site is in Orrington, north of Portland. According to legal filings, the plant sent mercury-contaminated brine sludge into its sewer and the river daily from December 1967 through June 1970 when it operated as a chlor-alkali plant. Maine’s Department of Environmental Protection website says the plant had several owners from 1967 through 2000 and produced chlorine, sodium hydroxide, chlorine bleach, hydrochloric acid and the pesticide chloropicrin.
Environmental groups have been calling for years for remediation of the river, which is part of the largest river system located entirely within the state.
Alliance spokesman Mike Tipping said he expects more “legal wrangling” once the options are available to the court. But he also said an end to the long-standing conflict is coming into focus.
“We’ve come a long way, and we’re close to finally getting the cleanup that people who live along the Penobscot deserve,” he said.
Mallinckrodt is a subsidiary of medical device giant Medtronic, based in Dublin, Ireland. Medtronic’s operational headquarters are in Minneapolis.