Vega Alta Public Supply Wells is a 50-acre well field in Vega Alta, Puerto Rico, operated by the Puerto Rico Aqueduct and Sewer Authority to supply drinking water to the community. Testing in 1983 found volatile organic compounds, or VOCs, in the groundwater and soil. The site was added to the federal Superfund program in September 1984. Today, 13 businesses operate on the property, employing 355 people and generating roughly $102.3 million in annual sales.
EPA identified 16 contaminants of concern, all found in groundwater. They include trichloroethene, tetrachloroethene, benzene, toluene, chloroform, 1,1,1-trichloroethane, 1,2-dichloroethane, and acetone, among others. A baseline health risk assessment found cancer risks for children and adults from groundwater ingestion that exceeded EPA's acceptable range. The main chemicals driving those risks are 1,1-dichloroethene, ethylene dibromide, trichloroethylene, arsenic, and beryllium. Non-cancer hazard indices for children and adults from groundwater ingestion were 22 and 9.4, both above the goal of 1.
Cleanup is organized into two operable units. The groundwater unit uses air stripping and carbon adsorption, with treated water discharged to surface waters under a permit. A groundwater extraction and treatment system has been running since December 2002 and processes about 20 million gallons of water each month. The soil unit used a vapor extraction system, which ran from December 2002 through October 2008 and removed 2,750 pounds of VOCs before being permanently shut down. Soil cleanup is complete and allows unrestricted use of that area. Construction across the site was completed in March 2003.
EPA has determined that human exposure and groundwater migration are both under control. Community drinking water meets federal and state standards, and affected residents were connected to uncontaminated supplies after the original wells were shut down. A five-year review completed in June 2024 confirmed the remedy remains protective of public health and the environment. The site achieved sitewide ready for anticipated reuse status in September 2016 but has not been deleted from the National Priorities List.
Community members can review site records at EPA's Caribbean Environmental Protection office in Guaynabo, Puerto Rico, or at Puerto Rico's Department of Natural and Environmental Resources office in San Juan. No Community Advisory Group has been established for this site. For questions, residents can contact the EPA's Community Involvement Coordinator or Remedial Project Manager.
