The Del Monte Corp. (Oahu Plantation) site is a former pineapple plantation near Kunia Village in Honolulu County, Hawaii. Del Monte grew and processed pineapple there from about 1946 to 2006. EPA added the site to the National Priorities List (NPL) in December 1994 after pesticides used to control worms contaminated soil and groundwater. A 500-gallon pesticide spill in 1977 near the Kunia drinking water supply well made contamination worse. The Poamoho section of the site was removed from the NPL in January 2004 after investigations showed it posed no significant threat to human health or the environment.
Five contaminants of concern are present in groundwater. They are 1,2,3-trichloropropane, 1,2-dibromo-3-chloropropane, 1,2-dibromoethane, 1,2-dichloropropane, and bromacil. EPA determined that these substances pose an unacceptable risk to human health or the environment. All five are found in groundwater in Operable Unit 01.
Del Monte treated contaminated groundwater in the basal aquifer from 2004 until 2014. The cleanup covers three operable units addressing sitewide actions, groundwater, and soil. The groundwater remedy uses a combination of tools, including monitored natural attenuation (MNA), institutional controls, carbon adsorption, phytoremediation, and air stripping, among others. MNA relies on naturally occurring physical, chemical, and biological processes to reduce contamination over time. Physical construction across the site was completed by September 2008. The site reached sitewide ready for anticipated reuse status in May 2009, meaning all cleanup goals for current and future land uses have been met. Land-use controls are in place to prevent exposure to contaminated groundwater, and human exposure is currently under control. Groundwater migration data remain insufficient to confirm whether contaminated groundwater movement has fully stabilized, so monitoring is continuing.
EPA completed its fourth Five-Year Review in August 2025. The review included a site inspection, data analysis, and coordination with stakeholders. EPA concluded that the cleanup remains protective of human health and the environment. After the plantation closed, the land has been put to productive use. Tenants now include small farms, a seed corn operation, a beauty-products manufacturer, and U.S. Army housing. As of December 2024, the site supported 20 businesses employing 137 people.
Community members can learn more or ask questions by contacting the EPA's Community Involvement Coordinator or Remedial Project Manager. Site documents are available at the Wahiawa Public Library at 820 California Avenue in Wahiawa and at EPA's Regional Records Center in San Francisco.
