Drinking water quality in California schools

Sep 13, 2023

Findings from a recent study indicate that most California schools are providing drinking water that meets current safety standards. However, the authors suggest that continued attention and investments are needed to assure tap water safety in all schools. Researchers partnered with 83 schools from a representative sample of 240 California public schools to collect and analyze tap water samples for five common drinking water contaminants: arsenic, nitrate, hexavalent chromium, copper and lead. The first three may occur naturally in groundwater but can also come from agricultural or industrial activities. Lead and copper are heavy metals that may be found in building plumbing and can be present in tap water under certain conditions. No tap water samples violated the California state action level for arsenic or nitrate, two contaminants that should be brought to levels at or below state standards by water utility treatment of their sourcewater. Four percent of schools had at least one sample that exceeded California's proposed 10 parts per billion action level for hexavalent chromium. Four percent of schools exceeded the 1300 ppb state action level for copper. A notable feature of the study was its detailed analysis of lead in tap water. Four percent of study schools had at least one first-draw tap water sample that exceeded the 15 ppb state action level for lead, 18% exceeded the US Food and Drug Administration's bottled water standard of 5 ppb, and 75% exceeded the American Academy of Pediatrics recommendation of 1 ppb. Researchers found that turning on the affected taps to “flush” pipes for 45 seconds reduced observed lead concentrations above 15, 5, and 1 ppb to 2%, 10%, and 33% of schools, respectively. These findings provide valuable information for mitigating the presence of lead in tap water. The study, “A Comprehensive Examination of the Contaminants in Drinking Water in Public Schools in California, 2017-2022, was published online on September 4, 2023 in the journal Public Health Reports. It was conducted by researchers from the University of California's Nutrition Policy Institute, Stanford University and Virginia Polytechnic Institute.

By Christina EA Hecht
Author - UC ANR Nutrition Policy Institute Academic Coordinator
By Danielle Lee
Editor - Director of Communications & Research Engagement
By Lorrene Ritchie
Editor - Director of the Nutrition Policy Institute and Cooperative Extension Nutrition Specialist