Fellow Story

Settlement proposed to clean up mercury in the Penobscot River

Editor’s note: content in this article is excerpted from the Penobscot River Remediation website, their fact sheet, and an NRDC blog post.

When Karen Merritt received her Switzer Environmental Fellowship in 2006, she was working on her dissertation on the site of a court-ordered study to evaluate mercury contamination in the Penobscot River.

The study stemmed from a lawsuit by Maine People’s Alliance (MPA), the Natural Resources Defense Council (NRDC) against Mallinckrodt US LLC (Mallinckrodt) that found Mallinckrodt liable for the contamination of the Penobscot River in the late 1960s and early 1970s. The Court appointed a Penobscot River Mercury Study Panel to investigate the condition of the River and need for remediation.

Over the course of nine years, the Study Panel produced Phase I and Phase II studies, which were the subject of a trial in 2014 and a Court decision in 2015. The Court ordered a Phase III engineering report conducted to identify cost-effective remedial actions that would accelerate the recovery of the River.

Now a professional environmental engineer, Karen returned to the project as part of the science and engineering team that conducted the Phase III Study from 2016 to 2018. The results of that study have led to a 2021 proposed settlement that would allow the cleanup to begin.

Under the proposed consent decree, Mallinckrodt will fund $187 million in remediation and restoration work in the river, with up to an additional $80 million for specific contingencies. MPA, NRDC, and Mallinckrodt anticipate that the cleanup work will reduce mercury concentrations across the estuary, but also recognize that the Penobscot River is a complex ecosystem and exact benefits of any particular remedial measure may be difficult to predict and measure with certainty. The parties negotiated this settlement to avoid further litigation and delays and instead begin cooperative remediation of the river as soon as possible.

“Since working on the Penobscot River for my dissertation I've been involved with chlor-alkali site characterizations in the U.S., Canada, Latin America and Europe,” Karen said. “It's really meaningful to have this project here in Maine move through the process to a negotiated settlement.”

The proposed consent decree has been lodged with the U.S. District Court in Maine and will only take effect if the Court approves it. The Court will hold a public hearing in Bangor, Maine on October 1, 4, and 5, 2021, and consider public comments before deciding whether to approve it.

Visit the settlement website and see the additional resources below to learn more.

Additional Resources

Settlement website: https://www.penobscotriverremediation.com/

Hearings set over deal that would fund mercury pollution cleanup in Penobscot River: https://bangordailynews.com/2021/08/16/news/bangor/hearings-set-over-deal-that-would-fund-mercury-pollution-cleanup-in-penobscot-river/

Settlement fact sheet: https://cc8f5e0f-84eb-4cd2-8fb4-3c15445d4b1b.filesusr.com/ugd/0d660d_f0dc84728af84c09bc804f6165f12167.pdf

Penobscot Mercury Study website: https://www.penobscotmercurystudy.com/

Groups urge public comment on proposed Penobscot River mercury cleanup effort: https://mainebeacon.com/groups-urge-public-comment-on-proposed-penobscot-river-mercury-cleanup-effort/

NRDC Blog: https://www.nrdc.org/experts/nancy-marks/proposed-settlement-aims-clean-mercury-penobscot-river-estuary