LACONIA — The New Hampshire Department of Environmental Services (DES) has asked city officials to submit a plan for addressing lingering contamination from an abandoned burning dump that once operated off Frank Bean Road and Morin Road, near the Laconia Ice Arena, by June 1.
In December, Sovereign Consulting, Inc. of Concord, after undertaking a third assessment of the site, concluded that "a plan for mitigation of future risk at these properties is warranted." Last week, Molly Stark of DES responded to the report in a letter to City Manager Scott Myers.
Myers, who included $1.2 million for the project in his recommended 2014-1015 city budget, said yesterday that city officials are weighing different approaches and options to the site in consultation with Sovereign and DES. He said that the city was exploring measures to minimize the removal and disposal of hazardous material and contaminated soil, which represent the greatest potential cost of the cleanup. Meanwhile, Myers said that the city has already undertaken to pour concrete floors in the basements of two residential properties on the site.
The old burn dump is part of a site that sprawls over some 75 acres on either side of Frank Bean Road, most in the city and some in Gilford. which also includes an abandoned landfill, the Morin Road Landfill. The burn dump itself extends over four lots — two residential and two commercial — totaling about 3.5 acres. Three of the lots abut one another on the west side of Frank Bean Road and the fourth is bordered by Frank Bean Road to the west and Morin Road to the east.
Sovereign sunk monitoring wells and soil borings to determine the extent and nature of materials at the burn dump. The report estimates the dump stretches along Frank Bean Road for about 1,000 feet and is 250 feet wide at its widest point. Likewise, the dump is between 15 feet and 20 deep, though some refuse was found at a depth of 32 feet. Assuming dimensions of 1,000 feet by 200 feet by 15 feet, the report estimates the contains approximately 110,000 cubic yards of "burn dump material."
Like earlier investigations, Sovereign also found metals and polycyclic aromatics hydrocarbons (PAHs) and volatile organic compounds (VOCs)in excessive concentrations. In addition, chlorinated VOCs were detected on three of the four lots, trichloroethylene on one lot and petroleum residues on another. But, the report noted "significant adverse impact to native soils has not been documented." Nor did samples of private wells serving the four lots indicate adverse impacts to the quality of drinking water.
Sovereign suggested that a mitigation plan could include some combination of removing and covering the burn dump materials, differentiating between the commercial and residential properties and changing or restricting uses of the site. However, Stark advised Myers that DES was unlikely to support restricting the use of residential property to spare the cost of reducing contamination of soils to safe levels.
Sovereign also recommended additional rounds of drinking water and groundwater samplings, along with additional borings to define the southern extent of burn dump materials. Stark confirmed that DES expected that these further tests would be conducted and the results attached to the plan — known as a "remedial action plan" or RAP — for mitigating the risks to public health, especially groundwater and air quality.
Stark acknowledged that the city would defer investigation and remediation of conditions at the Morin Road Landfill until the issues at the burn dump are resolved.
The site first drew the attention of DES in May, 2003 when David Farley, doing business as Dolphin Point, LLC, a marine contractor, complained of encountering buried refuse and foul odors while excavating for a foundation on his lot on Frank Bean Road.
In 2008, Weston Solutions, Inc. found levels of six metals as well as volatile organic compounds (VOCs) and polycyclic aromatics hydrocarbons (PAHs), which are byproducts of burnt fuels, in samples collected across the 75 acres, including the burn dump. Levels were sufficiently elevated to warrant further investigation.
Three years later Terracon Consultants, Inc. reported that a thin layer of clean fill covered the site and concluded that surface soils were unlikely to pose a significant risk to human health. However, DES replied that a risk assessment of surface soils would not diminish the requirement for mitigation, suggesting resources would be better applied to remedial measures, and requested the further investigation performed by Sovereign.