Arsenic in US correctional facility drinking water, 2006-2011

Abstract

Background: Very little is known about the quality of drinking water in US correctional facilities (e.g. detention centers, prisons, jails, etc.), which disproportionately detain people of color. The current Environmental Protection Agency’s maximum contaminant level (MCL) for arsenic in public drinking water is 10 µg/L. We estimated drinking water arsenic concentrations in US correctional facilities to determine if incarcerated persons remain at risk for chronic, elevated water arsenic exposure relative to the non-incarcerated US population.Methods: We obtained 230,158 arsenic monitoring records for 37,098 community water systems (CWSs) from the Environmental Protection Agency’s Third Six Year Review of Contaminant Occurrence dataset (covering 2006-2011). We compared six-year average arsenic concentrations in all CWSs versus CWSs exclusively serving correctional facilities. We separately evaluated the Southwestern US (where groundwater arsenic concentrations are relatively high) versus non-Southwestern US.Results: Average six-year water arsenic concentrations were higher for CWSs exclusively serving correctional facilities in the Southwest (6.41 µg/L, 95% CI 3.48, 9.34) compared to all other Southwestern CWSs (3.11 µg/L, 95% CI 2.97, 3.24) and to other CWSs across the rest of the US (1.39 µg/L, 95% CI 1.35, 1.42). Compared to other US CWSs and to other Southwestern CWSs, correctional facility CWSs in the Southwest were more likely to report six-year arsenic averages exceeding 10 µg/L (1.6%, 5.8%, and 26.1% of systems, respectively).Conclusions: CWSs exclusively serving correctional facilities in the Southwestern US reported average water arsenic concentrations twice as high as those reported by all other CWSs in the Southwest, and more than a quarter reported six-year averages exceeding the EPA’s regulatory MCL. Strict enforcement of the EPA’s drinking water regulations and a comprehensive review of other drinking water contaminants in CWSs serving correctional facilities is necessary to protect the health and human rights of all incarcerated persons in the US.