From the early 1970s until about 1982, a portion of the site known as Module 1 received large quantities of waste, which included rubber, carbon black and other fillers, oils, and mixed solvents. This material consisted of wastes containing mainly benzene and toluene.
To mitigate the effects of contamination the City of Salinas and the Salinas Valley Solid Waste Authority (SVSWA) undertook a range of actions to address site contamination. One action was installing a ground water pump-and-treat system, which involves pumping contaminated ground water to the surface via 23 extraction wells, passing it through a passive air stripper, and treating the gases removed in the stripper with activated carbon before they are discharged to the atmosphere.
Air Quality Impact Analysis, Human Health Risk Evaluation, and CEQA Assistance were performed. SVSWA hired SCS Engineers as part of a team to help determine the regional air quality impacts, including a human health risk assessment, which was evaluated as part of an Environmental Impact Report (EIR) for four different combinations of the expansion of three regional landfills and the placement of 10 regional transfer stations throughout the Salinas Valley. Module 1 of the Crazy Horse Landfill contained hazardous waste, including burn ash, which also had to be evaluated for potential health risks. The risks assessments included an evaluation of risks from diesel exhaust from mobile equipment and vehicles.
First Pacific Energy and then Covanta Energy operated an interior landfill gas collection system for electricity generation on the site, while the Salinas Valley Solid Waste Authority operated a perimeter system to assist in the control of both on and off-site LFG migration. The Power Generation Facility system was recently dismantled and decommissioned during the final closure of the landfill in 2010 and is the site is being re-evaluated for future energy development.
The Crazy Horse Sanitary Landfill stopped accepting waste and closed to the public in 2009. The landfill base is composed of six unlined acres beneath Module 1, with 51 unlined acres beneath the primary landfill, and 15 acres of lined module. The three phases (15 acres total) of the main landfill on the western side which were lined in accordance with Subtitle D solid waste regulations in 1993. These lined modules were constructed with a composite liner system which has enabled the landfill to use this area for leachate re-injection obviating the need for off-site transport of this landfill generated waste stream. This has increased the safety of the public by removing the potential for an off-site spill during transport.
The landfill closure plan included a final cover to enable the future use of photovoltaic (PV) technology on the landfill cover system. The National Renewable Energy Laboratory (NREL) conducted a feasibility study to evaluate renewable energy production at the site as part of the RE-Powering America’s Land initiative and found the site location is considered a suitable area in which to implement solar PV systems. According to Technical Report NREL/TP-7A30-57893, published in March, 2013:
Using land that cannot be used for other purposes would minimize the environmental impact of a solar generation plant. Installing a PV system on the compromised land at the site could generate approximately 5.2 million kWh annually and represent a significant distributed generation facility for the area.
For multiple reasons—the high cost of energy, the dropping cost of PV, and the existence of a good solar resource and possible incentives—this report finds that a PV system is a reasonable use for the site. A government-owned PV system that provides a reasonable payback and is easy to implement is one recommended option if off-takers for the power can be found. Alternatively, a third-party ownership PPA may be the most feasible way for a system to be financed and installed on this site.
SVSWA continues to work closely with the EPA, as the agency continually reviews the effectiveness of Superfund cleanup actions. SCS Engineers continues to monitor the site providing post-closure care operations and maintenance. As part of the ongoing efforts to improve compliance SCS uses both its data management and reporting system called SCS DataServices® and has installed its SCS Remote Monitoring and Control® (SCS RMC®) systems on all the environmental control systems to generate reports for submission to regulatory agencies, and to maximize operational reliability to maintain the public safety. Land surrounding the site is used for residential and agricultural purposes. Approximately 6,200 people obtain clean drinking water from private wells located within three miles of the site.
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