Attorneys and experts on both sides of a contentious case involving one of the most polluted waste sites in Maine are squaring off in front of the Board of Environmental Protection over the next two weeks. At issue is an order directing Mallinckrodt LLC to remove thousands of tons of mercury-contaminated soil from the former HoltraChem chemical plant in Orrington on the banks of the Penobscot River. Mallinckrodt is appealing the 2008 order on the grounds that it is technically flawed, potentially risky and too expensive to ever achieve.

The case involving Mallinckrodt, and later HoltraChem, has been brewing for years, ever since Mallinckrodt opened and operated a chlor-alkali plant in Orrington in 1967 and began discharging mercury directly into the Penobscot River until 1970.

Among other things, the plant produced chlorine, caustic soda and sulfuric acid for papermaking. Later, the operation was sold to HoltraChem which eventually went bankrupt. Left at the 235 acre site: five hazardous waste landfills with no liners and no leachate collection systems, and what Department of Environmental Protection Commissioner David Littell says is a big threat to the environment and to public health.

"This site is one of the most heavily contaminated sites in the state, not just with mercury but with carbon tetrachloride and trichloroethylene and chloropictrin which is a fumigant pesticide," Littell says. "Those are all carcinogens. They're all highly toxic. We've detected mercury in earthworms and deer mice at the site. It's a heavily contaminated site that's impacting the streams on site. We need this site cleaned up."

The problem with mercury is that it doesn't break down in the environment. And that's one reason Commissioner Littell says he ordered the removal of the landfills, the contaminated waste hauled away to a secure site in Canada and the groundwater treated.

Prior to the DEP's order, Mallinckrodt says it spent about $40 million doing remediation, including groundwater monitoring at the site. But the company objects to removal of all five landfills, which contain 360,000 tons of contaminated soil and which would cost more than $200 million.

"Mallinckrodt has not walked away from this site and, in fact, has spent considerable time, effort and money improving this site," says Jeff Talbert, an attorney representing Mallinckrodt. He says there are four options for cleaning up the former HoltraChem site, and Mallinckrodt only objects to one of them, the so-called "dig and haul remedy" ordered by the DEP.

"You dig up all five landfills and take them to Canada, which is the closest facility. It's the longest to implement at approximately nine to 12 years. There will be significant mercury emissions from digging up all the landfills, significant remediation generated waste from just hauling all this material up to Canada," Talbert says. "It costs twice as much as the next most expensive option, and it will take 11 to 16 years to meet the protection standards for mercury."

Talbert says the company has talked to a dozen consultants about the four options and not one of them has recommended the DEP's option. Instead they suggest removing the most hazardous landfill, landfill number one, at a cost of $94 million and meet standards in seven to ten years.

Other options include capping all five landfills or digging them up and putting them into a single secure container unit on the site. Ed Bearor, an attorney for the town of Orrington, says the town, which will soon own the site, is open to hearing about all of the options.

"What we're interested in is hearing now what the best available evidence and science presented leads us to conclude would be the best resolution regarding this site for the town of Orrington. There is a lot of land associated with the former HoltraChem site that we hope will be available someday for development, so we are interested in seeing that it's handled in an appropriate way, of course."

Attorney Jeff Talbert says that prior to 2004, even the DEP's own technical staff were suggesting that removal of all five landfills was unrealistic. One staffer's memo says there could be an increase of mercury contamination to surface water in the short term. Another indicates that the "landfills are large but stable." Other notes from the time point to improving conditions at the site.

Commissioner Littell says there's an easy explanation about the apparant contradiction between then and now. "The department always has, especially in a large matter like this that's been going on for two-and-a-half decades, open, frank discussions and we had those within the department and that's no surprise."

What's more of a surprise, says Littell, is that Mallinckrodt now says it's willing to do three clean-up options not including the department's preference. Littell says that is a change of position and a step in the right direction. The public will be given a chance to comment on the case on Thursday night in Orrington. A decision by the BEP is expected in the next several months.