In partnership with Universidad del Valle (UVG) in Guatemala City and Dr. Edwin Castellanos we created and ran a citizen science approach to test drinking water quality in Guatemala City during the COVID-19 pandemic. With UVG’s support to distribute and ship back completed drinking water samples, we devised an updated sample collection strategy directly supported by our UVG collaborators. This effort was the first large-scale household analysis of metal and PFAS in drinking water of Guatemala City residents and helped inform participants and water utilities about contamination, provide RTI with data to generate scientific stature, and add remediation cost information for our hydro-economic modeling work.