U.S. EPA Contaminated Site Cleanup Information (CLU-IN)

U.S. Environmental Protection Agency
U.S. EPA Technology Innovation and Field Services Division
Aerojet-General Corporation, Rancho Cordova, CA
Superfund NPL

Click on images
below for details

Current 6-MW Farm
Air Stripping
UV Reactors
Ion Exchange
and FBRs

Cleanup Objectives: Treat ground water with high concentrations of trichloroethylene, perchlorate, N-nitrosodimethylamine, and other contaminants released during past manufacturing of rocket engines and propellants

Green Remediation Strategy: Capture solar energy in remote portions of the site to produce electricity that could offset air emissions associated with using utility-supplied electricity for extracting and treating more than 20 million gallons of ground water each day, while continuing redevelopment of uncontaminated areas in accordance with Smart Growth principles

  • Formed a public/private partnership among Aerojet, Solar Power, Inc. (an energy developer), and the Sacramento Municipal Utility District (SMUD) to evaluate feasibility of generating electricity from onsite solar energy resources
  • Implemented a power purchase agreement (PPA) that enabled the energy developer to own, operate, and maintain the solar farm on property leased from Aerojet and provided Aerojet with long-term reduced rates for purchasing electricity from the SMUD
  • Formalized an Aerojet indemnification releasing the developer from cleanup liability under Superfund
  • Designed a solar energy system that maximized power output through use of single-axis trackers which could continuously align the anticipated photovoltaic (PV) collectors with the sun's daily east-west arc
  • Minimized disruption of indigenous flora and promoted fauna re-population through selection of PV modules that could be mounted on ground-inserted beams instead of structures with concrete footing
  • Designed a configuration involving adequately spaced rows of PV modules to allow installation of additional groundwater monitoring wells in the future, if needed
  • Financed the solar project's $20 million cost through $13 million in SMUD incentives over a 10-year period


  • Completed designs for the solar farm within three months, due to advanced planning by the developer and streamlined consensus and permitting processes among the regulators, local utility, developer, and other stakeholders
  • Completed the first phase (3.5 MW) of solar farm construction over a six-month period ending in June 2009, which involved installing more than 18,000 200-watt, silicon-celled PV panels covering 20 acres
  • Initiated the second phase (2.4 MW) of solar farm construction on an additional 20 acres in November 2009 and completed construction seven months later
  • Began fully operating the expanded (6-MW) solar farm in June 2010
  • Avoiding an estimated 6,000 tons of carbon dioxide, 4 tons of sulfur dioxide, and 5 tons of nitrogen oxide emissions each year due to electricity generation from renewable rather than fossil fuel resources
  • Offsetting approximately 30% of the total electricity used by the groundwater extraction and remediation equipment, including ultraviolet/oxidation, ion exchange, and air stripping units
  • Anticipating more than $10 million in electricity savings over the cleanup project's 25-year life, due to the lower cost of electricity purchasing established by the PPA
  • Beneficially re-using onsite land that sat idle for over 50 years, while allowing use of adjacent Aerojet property for continued rocket engine testing; future reuse of other areas may include residential, commercial, or industrial developments that could benefit from additional expansion of the solar farm

Property End Use: Ongoing aerospace equipment manufacturing

Point of Contact: Kevin Mayer, U.S. EPA Region 9

Update: April 2011

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