The case to determine what Mallinckrodt US LLC must do to clean up mercury contamination in the Penobscot River will go to trial May 7.

According to court documents, in 2002 Mallinckrodt was determined to be responsible for the pollution at the contaminated HoltraChem site in Orono. It has been ordered to clean up several mercury contaminated landfills on the HoltraChem site, but it has not been determined what it should do about waters around that plant, which are under federal jurisdiction.

Following the 2002 decision, the court ordered the formation of a panel to study mercury contamination in marine life in the waters around the HoltraChem plant. The study’s findings were recently used to justify the closure of much of the Penobscot River between Stockton Springs and Verona Island to lobster fishing due to unacceptably high levels of mercury found in the shellfish.

That study will be the focus of the May trial, in which the National Resource Defense Council and the Maine Peoples Alliance are the plaintiffs. At trial the U.S. District Court in Bangor will determine whether the recommendations of the Study Panel — that Mallinckrodt perform remediation on the river to increase the rate of recovery for that estuary — should be pursued. The surface sediment in that area of the Penobscot River still has highly elevated levels of mercury contamination, according to the panel's report.

Last week, in a pretrial decision, Judge John A. Woodcock Jr. denied a motion by Mallinckrodt to exclude fact-based witnesses.

In January Mallinckrodt filed the motion with the U.S. District Court to exclude "fact witness testimony." In the motion attorney Jeffrey D. Talbert, who represents Mallinckrodt, argues the testimony is "not relevant" and "would prolong and complicate the pretrial process."

"The Phase II Report presents conclusions and recommendations based upon years of study by trained scientists," Talbert stated. "The Study Panel's findings, conclusions and recommendations are therefore extremely technical … Testimony by fact witnesses would not add to the Court's understanding of the Study Panel's conclusions."

The NRDC responded to the Mallinckrodt motion on Jan. 29 stating the witness testimony is relevant because "in determining whether to accept the Study Panel's recommendation to pursue active remediation of the river, the court must consider whether such injunctive relief would disserve the public interest."

Talbert disagreed and stated in a response filed Feb. 11 that not only are the witness testimony irrelevant, but it is largely opinion based.

"Much of the testimony [the NRDC] proposed 'fact witnesses' would offer is more in the nature of opinion testimony," Talbert stated. "Kenneth Wyman, a fisherman [from Stockton Springs], would testify that 'if the court allows contamination… to continue unabated, it will threaten both his livelihood and his family's health.' That sounds like Mr. Wyman's opinion."

With the judge's Feb. 28 order allowing fact-based testimony the plaintiffs will present six such witnesses, including Wyman and Stockton Springs resident Nancy Galland.