Drinking water instead of sugar-sweetened beverages is an important obesity prevention strategy. Although schools have taken great strides to improve drinking water access, the water crisis in Flint, Mich., and its aftermath have highlighted the importance of assuring that the water provided in schools is safe to drink. This study will partner with national experts in drinking water quality testing to conduct the first large-scale, representative, cross-sectional study of drinking water quality in schools. The study will leverage a sample of 240 randomly selected California schools that are participating in an ongoing Healthy Eating Research-funded study to evaluate the proportion of schools with drinking water quality violations. The aims of the current study are to: 1) assess the quality of drinking water (by testing for the key contaminants lead, copper, arsenic, nitrate, hexavalent chromium) in food service areas (FSAs) in a representative sample of 240 California public schools; 2) examine school characteristics associated with water quality violations in FSA water sources in California public schools; and 3) understand if school administrators’ report of water quality testing is associated with water quality violations in FSAs.