September 13, 2009 — Friday, September 11, 2009
More than a year has passed since members of the N.H. Department of Environmental Services have held an informational session on what is to come of Lower Liberty Hill in Gilford and still there is no straight answer on when action will begin to remove the coal tar-saturated soil at the site.
Members from National Grid, along with its environmental consultant, GEI Consultants, Inc., appeared at the Gilford Town Hall on Thursday evening to give an update to town officials and affected parties.
The coal tar found in the soil came from a manufactured gas plant which Gas Service Inc. operated in Laconia, and was deposited with the permission of the property owner at that time into a coal tar disposal pool. National Grid ultimately assumed responsibility for its cleanup and has researched remedial action alternatives (RAA) to dispose of the waste.
The town wants all of the coal tar still on-site to be removed but National Grid is pushing for only partial excavation of the contaminates. To remove the 121,000 ton of tar-impacted soil from the site would cost an estimated $16.8 million and would take two years to complete and replace with clean backfill.
Michael McCluskey, project manager for the site, said the DES has conducted four meetings over the past year to address comments from the past public forum and the agency has examined in-depth National Grid's progress.
"In the last meeting, National Grid did not have a final report, but they explained where they were," said McCluskey. "We ended up concluding that the original design was not going to meet the department standards and determined that contaminates could return."
National Grid came back with another plan, known as RAA5a, which implemented an active pumping system, a change which required the plan to be re-evaluated under DES regulations.
"Ultimately, DES felt that, by adding the pumping component, it wasn't a simple modification; rather, it was significant," said McCluskey. "We asked them to produce another addendum and now we have limited down to RAA1 and RAA5a which have been compared under specific criteria."
Jim Ash, vice-president of GEI Consultants, gave a presentation outlining the progress that had been made over the past year. Ash presented two remedial action options that could be used. He said the two options were ranked based on several criteria, including effectiveness, reliability, feasibility and ease of implementation, risk reduction, benefits, cost effectiveness and timeliness.
"After comparing all the criteria, the one that scored better was RAA5a, thus the justification of us choosing that one," Ash said.
RAA5a removes 80 percent of the contaminated material, contains the remainer of the contaminated soil inside a slurry wall and uses a low flow pumping system. GEI stated that it is more effective and reliable, had a shorter construction time, was more flexible for addressing unforeseen conditions as well as costing less.
That plan has a total project cost of $10,924,529, which includes the removal of 27,500 tons of tar-impacted soil and replacement with clean soil and will take around 38 weeks to complete, or one construction year.
Rick Cote of 58 Liberty Hill Road questioned National Grid's choice of a plan that leaves contaminates in the ground, rather than the one that called for a full extraction.
"Other than costs, why does National Grid want to leave contaminates in the soil?" Cote asked.
Representing National Grid was Michele Leone, manager of the New England Site Investigation & Remediation Program.
"National Grid is required under DES rules and the Public Utility Commission to choose a plan that is both cost-effective and is environmentally friendly," said Leone. "PUC watches us very carefully."
Leone said National Grid would not be recommending the proposal if it felt there was any risk involved.
"We picked the one that we thought was effective," Leone said.
In the audience was Meredith resident Keith Forrester, a professional environmental engineer who works in the area. He said he has been working with systems such as the proposed plan for decades and believes that a plan that implements a containment system would work well.
"As a professional, this approach is better than digging," said Forrester. "If I had the choice to live here, I would live here. The pump and treatment technique is there for your protection."
John Regan, DES project supervisor for the site, said that agency still must review the RAP Addendum No. 2, which will be done within the next two months.
"Once we get through our review, we're estimating it will be another 60 days and then we'll made a final decision," Regan said.
After the decision is made, Regan said, it is subject to appeal by any party that is directly affected. The design of the remedy will be determined after the final design of the plan is made, which only leaves a public information meeting to be held before the RAP is implemented.
Potential use of the land after the remedial action is complete differs slightly from plan to plan. In RAA1, which calls for a complete removal of the contaminants, an open space would offer the possibility of future residential use. In RAA5a, there would still be an open space, but it is less likely that a residential building would be constructed on the site.
Gus Benavides, chair of the Gilford Board of Selectmen, assured the audience that the town was pushing for 100 percent of the contaminates to be removed.
"We're not only here for you, but for all the residents in Gilford," said Benavides. "We will keep pushing until we get what is necessary."
