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DES 'pauses for a moment' on Liberty Hill action

July 08, 2009
National Grid proposed changes to their remediation plan for the Liberty Hill coal tar site last month, but the Department of Environmental Services said last week that the "modification" is actually a new plan.

"We reviewed it and decided that it was not a modification," said Michael McCluskey, from DES Hazardous Waste Management Bureau, "but a new plan looking for some guidance from us."

The original plan was approved by DES, but during the technical meeting between the parties to finalize and review details, National Grid was performing groundwater modeling, which can show how water is flowing now and years from now. The results of the groundwater testing showed that in the future there might be some leakage of the slurry wall. National Grid selected a well to go into in and siphon off any contaminate water.

The leakage in the study was shown to be 50 years or more in the future, if it happened at all, and it would be minimal. The well would be put in to take away any contaminated water in the future. The water would not start out as contaminated it is a prevention measure for the future. It would pump about two gallons per minute.

McCluskey said that it puts the project back a few steps, but it should not be not much farther back than they were before the leakage discovery. He said National Grid has already done most of the work and the research for the project, so this will be an addendum onto their preliminary decision they made last winter. McCluskey said it shouldn't put the project back far in terms of time.

"We hoped to implement the plan this fall," said McCluskey, "but I don't know about that now. This is only one of the factors in the timeline and not a big one in the grand scheme of the project. It's more like pausing for a moment."

Residents and other interested parties can view the documents from the Liberty Hill site online at the DES Web site in the database section by searching for the case number, which is 200411113. Letters between the town, DES and National Grid are available to view as well as the studies done on the site.

"By adding an active component to the proposed remedy," wrote DES to National Grid regarding the well, "the Department does not believe it would come to the same conclusion for each of the criterion. For example, the previously proposed passive containment system would have had minimal long term management requirements while an active system necessitates long term operation and maintenance obligations."

David Graves, representative from National Grid, said they are going to comply with the requests outlined in the letter from DES. This includes a comparison study between complete removal of the affected soil. DES asked for a cost analysis, long-term costs, feasibility and time for both jobs.

"It will take several weeks to provide them with the information," said Graves. "This will put us a little behind where we were."

Martin Lord & Osman
Varney Smith
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