Groundwater quality of individual wells and small systems in Arizona

Abstract

A study of the microbial, physical, and chemical quality of nondisinfected individual and small groundwater drinking water systems in Arizona was conducted. Forty‐nine groundwater sources were tested (10 small public water systems and 39 individual wells). Forty‐three percent of the systems were positive for total coliforms, 16% for fecal coliforms, and 4% for Escherichia coli. Twenty‐nine percent of the wells were positive for enterococci, and 57% for Aeromonas hydrophila. Helicobacter pylori, noroviruses, rotaviruses, adenoviruses, enteroviruses, and hepatitis A were not detected. Metals that exceeded drinking water standards included arsenic, aluminum, iron, lead, manganese, molybdenum, selenium, and uranium. Most of the metals evaluated in this study were at greater concentrations in public drinking water systems than in individual wells. In total, 95% of the well water sources exceeded at least one primary and/or secondary drinking water standard.