This chemical manufacturing plant along the Penobscot River in Orrington, seen in 1997, released between six and 12 metric tons of mercury while it was under the control of Mallinckrodt US LLC in the late 1960s and early 1970s, according to a court-order study. Press Herald Photograph

The Department of Environmental Protection issued a notice of violation to Mallinckrodt US LLC over failing to remove mercury that has contaminated the surrounding soil for more than a decade.

In the notice issued Wednesday, the DEP charges that Mallinckrodt has done an insufficient job removing the hazardous materials and has attempted to dodge its legal responsibilities surrounding the cleanup.

The company, which operated a chemical manufacturing plant along the Penobscot River in Orrington between 1967 and 1982, was deemed responsible for cleaning up the river and surrounding area by a federal judge in 2015. In 2022, a judge ordered the company to pay at least $187 million to clean up the region.

While under Mallinckrodt’s control, the site discharged between six and 12 metric tons of mercury in the late 1960s and early 1970s, according to one court-ordered study.

The plant was eventually shut down in 2000 when then-owner HoltraChem Manufacturing Co. declared bankruptcy.

The department charges that Mallinckrodt has violated its orders “on an ongoing, daily basis” since at least Feb. 5, 2024, by failing to properly remove and dispose of mercury-contaminated soils. The company has also failed to provide the required corrective measures implementation plan during that time frame, the department said in its notice.

The department previously ordered that all soil with mercury concentrations above 2.2 parts per million must be removed from the plant. It reminded Mallinckrodt of this rule in a June 2023 letter, according to the notice. The company replied nearly two months later, requesting a meeting to discuss potential “flexibility” in fulfilling its requirements, according to the notice.

The DEP reiterated that “although meeting the 2.2 ppm … may present technical challenges,” that threshold is part of a legal order “and is therefore non-negotiable.”

Months of back and forth followed, during which time the company attempted to submit insufficient cleanup plans despite warnings by the DEP, the notice said.

The DEP offered modifications to Mallinckrodt’s latest plan in January 2024, which the company has still not addressed, according to the notice issued Wednesday. In December, it sent a letter to the Board of Environmental Protection asking to be relieved of the department’s orders, according to the notice.

“Despite the requirement of the DEP Orders and repeated reminders by the DEP that Mallinckrodt remove all soils at the Site that exceed the MPS of 2.2 ppm for mercury to protect public health, safety and the environment, Mallinckrodt has repeatedly attempted to evade this clear requirement,” the DEP said in the notice

Testing completed in 2023 found some soil surrounding the plant to contain as much as 12.8 ppm of mercury, according to the notice.

Mallinckrodt must submit a detailed plan for removing solid materials from the remaining areas within 30 days of receiving the notice. If the DEP approves that plan or provides approval with modifications, the company will then have 15 days to begin implementing it.

The department did not specify the precise consequences, including fees, it plans to pursue for Mallinckrodt.

Under Maine law, failing to adhere to orders and decisions imposed by the department commissioner or Board of Environmental Protection can carry fines of between $100 and $10,000. The maximum penalty increases to $25,000 for violations involving hazardous waste, the department said in its notice.

A spokesperson for Mallinckrodt Pharmaceuticals said that “since 2013, the Orrington, ME, site and the ‘Mallinckrodt US LLC’ entity have been owned by Covidien, subsequently acquired by Medtronic.”

“Mallinckrodt Pharmaceuticals became an independent company via a spin-off from Covidien in 2013. Given that, Mallinckrodt Pharmaceuticals is not responsible for this site or the Notice of Violation recently issued by the Maine Department of Environmental Protection,” they said in a written statement Friday.

The notice does not name or reference Mallinckrodt Pharmaceuticals.

This story was updated at 3:08 p.m. Friday to include the pharmaceutical company’s statement.