Crazy Horse Sanitary Landfill

Overview

Crazy Horse Sanitary Landfill sits about 5 miles from Salinas, California and covers roughly 125 to 160 acres. The site has accepted waste since 1950 and was added to the National Priorities List in August 1990. It stopped taking waste in 2009 and completed formal closure in 2014. The facility is now in the remedial investigation phase, with a combined remedial investigation and feasibility study underway since September 1993 and estimated to finish between September and November 2028. That study will lead to a Record of Decision, and full remedial construction has not yet started.

The main contamination concern is groundwater. A local manufacturing plant disposed of rubber materials, carbon black, fillers, oils, and mixed solvents at the landfill during the 1970s, and landfill operations overall contributed hazardous chemicals to the groundwater beneath and around the site. The California Regional Water Quality Control Board oversees cleanup, with involvement from EPA, municipal authorities, and potentially responsible parties.

Several protective measures are already in place. About 6 acres were closed and covered in 1988 with a high-density polyethylene (HDPE) membrane and two feet of soil. The Salinas Valley Solid Waste Authority installed a groundwater treatment system using 23 extraction wells and an air stripping process. Treated water is either reinjected through 27 recharge wells or used for dust control. The site also runs leachate recovery and landfill gas recovery systems. Residential wells near the site were sealed or converted to extraction or monitoring wells. EPA has determined that human exposure is currently under control and that contaminated groundwater migration is stabilized with no unacceptable discharge to surface water.

Despite these steps, physical cleanup construction is not yet complete, and the site does not yet meet all requirements for its anticipated future use. EPA is reviewing whether current actions are effective enough or if additional cleanup measures are needed. The City installed a cover designed to support future photovoltaic technology, and the National Renewable Energy Laboratory completed a feasibility study for renewable energy production at the site. Additional solar energy evaluations are in progress.

Community members with questions can contact the EPA's Community Involvement Coordinator or the Remedial Project Manager.