Claremont Tar Site to Be Cleaned
Claremont — A highly contaminated parcel on the north side of the Sugar River that once supplied gas to Monadnock Mills could possibly be cleaned up before the end of the year.
Gary Lipson, the on-site coordinator with the Environmental Protection Agency’s Boston office, said Tuesday officials are in the process of developing a cleanup plan for the coal tar imbedded in the soil with the property owner in Pennsylvania.
“We would like to begin the cleanup in September or October,” Lipson said. “We will look to excavate a vast majority of the contamination and replace it with clean fill.”
Lipson estimates the clean-up plan would cost about $2 million, but the city will not be on the hook for the costs.
The one-acre site off North Street is located on the river upstream from the pedestrian bridge and a dam and across from the Common Man Inn. Lipson said that the EPA and state Department of Environmental Services have reviewed and made comments on a draft plan and are now working on finalizing it.
Last week, the City Council authorized City Manager Guy Santagate to negotiate a settlement with the EPA and the property owner for remediation of the hazardous material.
Santagate said negotiations with state and federal officials are in progress and he is hopeful an agreement will be reached. “We are making progress,” he said.
Santagate said the city is willing to take ownership of the site but only after it is cleaned and the city is protected against current or future liability.
“We want the site cleaned up but we don’t want to be on the hook for any future liability,” Santagate said. “No ownership unless they clean it up as best as they can.”
Lipson said the city’s position is exactly what the EPA wants to achieve.
“We are trying to make sure there is no future impact on the city,” he said.
A complicated ownership trail due to mergers, buyouts and bankruptcies over the years has made assigning liability difficult, Lipson said. “But when it comes down to it, Amerigas of King of Prussia, Pa., is who the owner is,” he said.
Santagate and Lipson both agreed that after the cleanup there would be restrictions on the development of the property because some contamination will probably remain. While excavation can remove the contaminants that remain between two and 10 feet deep, there are some pockets with contaminants as deep as 18 and 19 feet, Lipson said. But the deeper contamination can be contained to a large degree by a material that hardens the soil so groundwater flows around it, he said.
A coal gasification plant operated on the site from around 1900 to the 1940s. The manufactured gas was produced by Monadnock Mills to supply power to its textiles mills on the south side of the river. The gas was transported across the river through a pipe on an iron bridge that workers used to get to their jobs in the mills. The historic bridge is still standing.
Coal tar, which contains some carcinogens, was a byproduct of the gasification process and core samples of the soils have shown it has “saturated” about two-thirds of the privately-owned property, Lipson said in May 2012 when divers went into the Sugar River trying to determine how deep out into the river sediment the coal tar was present.
The tar has also seeped onto adjacent city-owned property. The directive from the council last week to Santagate is that the city be released from liability on any of the properties.
On Tuesday, Lipson also said that because the building — which is in total disrepair — is on the New Hampshire State Register of Historic Places, the EPA has hired a company specializing in historic structures to document the site with photographs and measurements of the building to meet the criteria of the state historic preservation office.
“We will be providing some historical legacy for the site.”
Though it has taken years to reach this point , Lipson is confident they will be successful.
“This can be a win-win for everyone. I really think we will get there.”
Patrick O’Grady can be reached at email@example.com