Penobscot River cleanup study enters new phase

ELLSWORTH — The continuing effort to clean up mercury contamination in the Penobscot River has emerged from the shadows again.

Within the past few weeks, the engineering company charged with devising a plan to alleviate the impact of the mercury has established a website that provides a comprehensive look at the situation. It looks at how the problem was created, past efforts to deal with the contamination and the current status of a “Phase III Engineering Study” in which engineers and scientists are evaluating a variety of options to reduce the levels of mercury in the Penobscot River system and the resulting threats to human health and the environment.

The roots of this Phase III study date back at least to the 1960s when a predecessor of the HoltraChem Co. discharged mercury-contaminated wastewater from its Orrington chlori-alkali plant into the Penobscot.

In 2000, a coalition of conservation organizations sued HoltraChem and its parent, Mallinckrodt US LLC, in federal court to force them to clean up the river.

Almost three years later, the federal district court found that Mallinckrodt was liable for the contamination under the federal Resource Conservation and Recovery Act and ordered the company to fund a study of mercury in the Penobscot River.

In 2005, the court approved a plan for a panel of scientists to study the river and determine the extent of the harm resulting from mercury contamination to the Penobscot River south of the Holtrachem plant site, the need for and feasibility of a remediation plan to deal with that harm and the elements and timetable for a remediation plan.

The panel made a report to the court in 2008 and, later that year, ordered further studies in a “Phase II” plan.

One of the studies determined that American black ducks — popular game birds — wintering along the lower Penobscot River, particularly in an area known as Mendall Marsh, showed concentrations of mercury in their breast muscles more than twice the levels found statewide. The study noted that those concentrations of mercury were “well above the advisory limit for human consumption set by the state of Maine.”

According to the Department of Inland Fisheries & Wildlife, pregnant or nursing women and children under the age of 8 should not eat any amount of waterfowl taken from Orrington south to the southern tip of Verona Island.

Among the other consequences arising from data collected in the early studies, in 2014 the Department of Marine Resources closed an area of the Penobscot River north of a line between Wilson Point in Castine and Fort Point in Stockton Springs to lobster and crab fishing because of elevated levels of mercury found in the tissues of crustaceans caught in those waters. In 2016, the closure was expanded southward to a line between Squaw Point in Stockton Springs and Perkins Point in Castine.

In 2016, after a review of several options, the court selected the international engineering company Amec Foster Wheeler Environment and Infrastructure Inc. to perform an “evaluation of potential remedies for the mercury contamination below the HoltraChem site,” Phase III of the cleanup effort.

A team of engineers and scientists in the Amec Foster Wheeler office in Portland is laying out plans for further field studies and exploring the potential costs and benefits of different options for reducing the level of mercury in the river — and the potential threats to human health.

The Phase III study is focused on the section of the Penobscot River that is subject to the tide and includes the area from downstream of the former Veazie Dam, past Verona Island and Fort Point into the upper Penobscot Bay. This study area also includes Mendall Marsh and waterways such as the Marsh River, Orland River and Fort Point Cove.

So far, the most public evidence of the Phase III effort is a new website replete with information about the mercury in the environment, the history of mercury in the Penobscot, the court case and the prior and ongoing studies. According to the website, the study team is developing a “Community Involvement Program” to solicit information from a broad community of stakeholders and to keep the public informed of the study’s progress, proposed solutions, and how those proposals evolved. The website can be found at

Under court order, Mallinckrodt funded the two earlier studies, both supervised by a special master appointed by the federal court, and is paying for the current Phase III engineering study.

Stephen Rappaport

Stephen Rappaport

Waterfront Editor at The Ellsworth American
Stephen Rappaport has lived in Maine for nearly 30 years. A lifelong sailor, he spends as much time as possible messing about in boats. [email protected]
Stephen Rappaport

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