As part of the remedy at the Frontier Fertilizer site, 236 electrodes - components of an in-situ thermal treatment system - have been installed at the former site of an unlined 5-acre pond near the eastern city limits of Davis, California. The electrical rods will heat groundwater and volatilize contaminants, which will then be extracted and run through carbon filters to remove the chemicals.
As part of the same effort, a newly upgraded solar photovoltaic (PV) energy system will power the pump-and-treat system for tens of millions of gallons of contaminated groundwater each year. It marks the first time such a water treatment system will be 100% solar powered, officials said. In the initial configuration, installed in 2007, the PV system produced approximately 8,500 to 9,000 kilowatt-hours of energy, offsetting up to 5% of the site's annual electricity use for the pump-and-treat system operations, saving approximately $1,500 per year.
The entire remediation effort is expected to cost upward of $40 million. The federal government is funding the cleanup after determining that Frontier Fertilizer did not have adequate financial resources.
The eight-acre Frontier Fertilizer Superfund Site was used by two pesticide companies for close to 20 years as a distribution facility and disposal site for fumigants left behind after farmers sprayed their fields. The Barber and Rowland Company operated a pesticide and fertilizer distribution facility on the site from 1972 to 1982. The Frontier Fertilizer Company used the site from 1982 to 1987. Both companies handled chemicals on the western four acres of the site.