The Beede Waste Oil/Cash Energy site consists of two parcels totaling about 40.6 acres on Kelly Road in Plaistow near the junction of NH Routes 125 and 121A. Waste oil recycling operations had reportedly been there since the 1920s. More recent facility operations included waste oil processing and resale, fuel oil sale, contaminated soil processing into cold-mix asphalt, anti-freeze recycling, and other related industries.
Contamination on the site originated from poor storage and handling of waste oil and other products as well as the unlined and uncovered storage of large contaminated soil piles. Elevated concentrations of polychlorinated biphenyls (PCBs) were first detected by NHDES in waste oil found in several above-ground storage tanks following complaints of odors in 1979. Numerous notices, letters of deficiency, administrative orders and court orders to cease operations and perform investigation and remedial activities were issued from 1980 to 1992.
Following the cessation of commercial operations in 1994, more than 1.5 million gallons of oily liquid waste and sludge, stored in approximately 100 above-ground storage tanks and more than 1,000 drums, remained at the facility. The tanks and drums contained hazardous waste, including PCBs, metals, and volatile organic and chlorinated organic compounds. Seventeen large soil piles, totaling more than 27,000 cubic yards and containing varying levels of contamination, were also left on-site.
Properties in the surrounding residential neighborhood are served by individual water wells. Testing of drinking water wells found contamination, generally consisting of chlorinated solvents, at some adjacent properties. NHDES installed treatment systems on wells with contamination levels above Ambient Groundwater Quality Standards to ensure that residents can safely drink and use their water. NHDES and EPA continue to oversee the monitoring of water quality in residential wells in the vicinity of the site and the maintenance of the treatment systems.
Between 1992 and 1998, NHDES and EPA undertook interim measures and removal actions to mitigate exposure to contamination, including containment of the oil leakage to Kelley Brook and additional site fencing. In the summer of 1996, EPA initiated a time-critical removal action to remove much of the above ground hazardous waste. With the cooperation of NHDES and with supplemental State funding, the action was extended in 1997 to remove non-hazardous wastes, resulting in the removal and proper disposal of all tanks and drums and the materials in them.
Zones of contaminated soil and pools of oil floating on the groundwater table were found in the subsurface. The floating oil is referred to as light, non-aqueous phase liquid (LNAPL). The LNAPL at the site is contaminated with solvents, PCBs and metals.
EPA conducted a non-time-critical action between 1999 and 2005 to extract as much LNAPL from the subsurface as practicable, thereby cutting-off oil seepage to the Kelley Brook wetlands and reducing the mass of this major source of groundwater contamination. Approximately 91,000 gallons of LNAPL were removed from the groundwater.
The site was added to the National Priorities List in December 1996 and with funding from EPA, the remedial investigation/feasibility study (RI/FS) was initiated in 1997 under NHDES management. The RI report, which characterizes site conditions and evaluates the risks to human health and the environment, was released in February 2001. The FS report, which evaluates cleanup alternatives, was released in January 2002. The proposed plan for cleanup of the site was presented for public comment in June 2002. EPA carefully considered all comments received during the proposed plan’s public comment period and, with NHDES’s concurrence, selected the preferred alternative as the most appropriate remedial action for the site. This cleanup decision is documented in the Record of Decision (ROD) that was signed on January 9, 2004.
The ROD calls for remedial actions that will be protective for the anticipated future use of the site, which includes elderly housing, a community center and recreational fields. The ROD requires the excavation of sediments, soil piles and contaminated soil that is less than 10 feet below ground surface (bgs) for off-site treatment and/or disposal. Contaminated soil greater than 10 feet bgs, which is acting as a source of groundwater contamination, will be treated in-place using soil vapor extraction, and may possibly include heating the soil to enhance the removal of contaminants remaining in the deep soil. Contaminated groundwater will be extracted and treated on-site to restore it to Ambient Groundwater Quality Standards prior to on-site disposal. A groundwater management zone will be established to manage the contaminated groundwater and institutional controls will be implemented to prevent the excavation of soils greater than 10 feet in depth.
In June 2001, EPA sent general notice letters of liability to over 2,000 potentially responsible parties (PRPs), including about 2,000 generators, about 15 transporters and four current and former owner/operators. In November 2001, EPA completed an early (first) cash-out settlement with 496 PRPs who contributed relatively small amounts towards site contamination, i.e., de minimis parties. The first de minimis settlement raised $1.7 million that will be applied toward the cleanup costs for the site. In November 2002, EPA completed a second de minimis cash-out settlement with 415 PRPs, which raised $4.6 million for the site. In January 2004, EPA completed a third de minimis cash-out settlement with 12 PRPs who had submitted “ability-to-pay” claims and collected an additional $45,037 for the site. In December 2004, EPA completed a fourth de minimis cash-out settlement offer with 276 PRPs, which raised $10.7 million for the site. Thus, out of 1,700 parties that had been given the opportunity to settle their liability in four de minimis party settlement offers, 1,199 parties settled and contributed a total of approximately $17 million to be applied toward cleanup costs.
In September 2005, EPA issued an invitation to all parties identified by EPA as major generator parties, transporters and owners/operators to participate in negotiations for the performance of the remedy selected in the January 2004 ROD. These parties are essentially responsible for over half of the hazardous wastes brought to the site.
In 2006, negotiations of the terms of a Remedial Design/Remedial Action Consent Decree (CD) were conducted with a group representing the major PRPs, to reach a comprehensive settlement agreement with 101 potentially responsible parties. The agreement calls for the major settling parties to clean up the site under the oversight of the EPA and NHDES. The agreement provides for site-wide cleanup estimated to cost approximately $48 million, payment of over $9 million for future federal and state oversight costs, and recovery of over $17 million in past response costs incurred by federal and state agencies at the site. Under the settlement agreement, a group of de minimis parties and federal agencies are also resolving their Superfund liability by contributing funds needed to help clean up and restore the site.
On April 16, 2007, the CD was lodged in the District Court for New Hampshire, and was subject to a public comment period prior to approval and entry by federal court. Shortly after lodging, a group of major PRPs who signed the CD (hereinafter, “Performing Parties”) initiated some of the preliminary planning work associated with the $48 million comprehensive site cleanup plan selected in the 2004 ROD. The CD was entered by the Court on July 22, 2008 and, immediately thereafter, field work associated with several pre-design investigations and studies commenced.
Under EPA and NHDES oversight, the Performing Parties are conducting pre-design soil and sediment investigations to further delineate the extent and volume of contaminated soil (including soil piles) and sediment which will require excavation or treatment. The pre-design investigations have also included field activities and laboratory tests associated with a treatability study to determine the need for thermal enhancement of the soil vapor extraction system. The preliminary results of this treatability study indicate that thermal enhancement of the soil may be required to effectively remove the subsurface contamination that poses a long-term treat to groundwater quality. A groundwater treatability study was also performed to determine the appropriate treatment processes required to remove groundwater contamination and groundwater pump tests and infiltration tests were performed to support an extensive groundwater modeling effort to determine the design for the groundwater extraction, treatment and discharge system.
All pre-design investigations, treatability studies and the Preliminary Remedial Design Report (30% Design) are expected to be completed in 2010. The sequence of remedial action activities presented in the Record of Decision is currently under review by the EPA and NHDES. The focus of this review is to determine a sequence of remedial activities that results in restoring groundwater in the least amount of time. The sequence of remedial activities will be used to determine which component(s) of the overall design presented in the 30% Design should be moved to the 100% design phase first. The purpose of breaking the design up into smaller pieces after the 30% design is to accelerate the remedial action schedule.