General Electric operated a wiring devices manufacturing plant in Juana Díaz, Puerto Rico, from 1957 to 1969. During that time, roughly half a ton of mercury and about 4,000 cubic yards of defective switch parts and plastic scraps were discarded into a waste area on the property. The site was added to the Superfund National Priorities List (NPL) on September 8, 1983, because of the risk to roughly 10,000 residents living within 3 miles and a public drinking water supply well located about 1,500 feet from the waste pile.
Mercury is the contaminant of concern. It was found in groundwater, soil, and solid waste at the site. Investigations completed in 1993 confirmed that groundwater was not broadly affected by the waste pile. A storm drain system and retaining wall were installed in 1982 as immediate controls to stop contamination from moving toward nearby homes.
Cleanup was organized into two operable units (OUs). OU 01 covered groundwater, and OU 02 addressed soil. A remedy was first selected in September 1988, calling for a hydrometallurgical treatment process that used leaching to pull mercury out of contaminated soils and recover it. The remedial action began in April 1997. The first treatment phase wrapped up by March 1998, and a total of 13,596 tons of waste were sent to an appropriate off-site disposal facility. A consent decree covering the full site was finalized in February 1998, and all construction work was completed by June 20, 2000. EPA deleted the site from the NPL on October 16, 2000.
The site's cleanup goals have been fully met. Human exposure pathways are under control, and contaminated groundwater has remained stable in its original area rather than spreading further. EPA continues monitoring to confirm that stability holds. The site reached "sitewide ready for anticipated reuse" status on June 15, 2006, meaning all cleanup goals for current and future land uses are satisfied and required land-use controls are in place. As of December 2024, one business was operating at the location and employing 20 people.
Community members who want to review site records can visit Juana Díaz City Hall, the EPA Region 2 Superfund Record Center in New York, or the EPA Region 2 Caribbean Environmental Protection Division office in Guaynabo, Puerto Rico. For questions, contact the Community Involvement Coordinator or the Remedial Project Manager.
