Puerto Rico Southern Aquifer Water Sampling Project

Between April and May 2023, EPA conducted sampling of drinking water wells and the Guayama Drinking Water Treatment Plant in southern Puerto Rico. The effort was in response to the community’s concerns about coal ash deposited in southern Puerto Rico and its potential impact on groundwater used for drinking water. Results from the sampling effort showed that public drinking water from the Puerto Rico Aqueduct and Sewer Authority public water system wells and the Guayama Water Treatment Plant do not exceed drinking water criteria for metals.

Read a report summarizing the sampling and review the data below:

• Southern Puerto Rico Drinking Water Well Sampling Report (September 2023) (pdf) (6.18 MB) .
• Appendix A Table 1 Historical PRASA Data (xlsx) (7.48 MB) .
• Appendix B Tables 1 and 2 PRASA Wells Guayama Drinking Water Treatment Plant Sample Results (xlsx) (106.12 KB) .

On October 10, 2023, EPA presented the sampling results to the community. Access the presentation slides below:

• Summary of Puerto Rico’s Southern Aquifer Drinking Water Sampling (pdf) (2.07 MB) .
• Resumen del muestreo de agua potable del acuífero sur de Puerto Rico (pdf) (2.04 MB) .