Mallinckrodt Pharmaceuticals is under a Notice of Violation by the Maine Department of Environmental Protection for failure to clean up contamination.

The company’s manufacturing facility on the Penobscot River in Orrington released heavy mercury contamination during its operations between the late 1960s and early 1980s

The contamination was released into the surrounding soils and groundwaters as well as the Penobscot River, and DEP says a significant amount remains in place.

The Notice of Violation says Mallinckrodt has ceased to make meaningful progress in cleaning up the area over two years.

The Department has not specified the consequences of the notice, except to say it expects Mallinckrodt to immediately resume cleanup efforts.

DEP says it has pursued the site’s cleanup since 2008.

Mallinckrodt has been involved in several legal matters, including a $1.7 billion opioid settlement and a bankruptcy restructuring that reduced the settlement amount.

Mallinckrodt develops and manufactures specialty pharmaceutical products, including controlled substances like hydrocodone, hydromorphone, and oxycodone.