What's in City of Cupertino, CA tap water

Every one of the 68 contaminants measured in City of Cupertino, CA's 2023 Consumer Confidence Report is below its federal limit. "Safe" under the EPA's drinking-water standards is health-based, not aesthetic — but by those standards, no measured contaminant in this report exceeds its enforceable threshold. Individual health concerns (e.g. immunocompromised, infant, pregnancy) may warrant additional filtering regardless of compliance.

68 contaminants were measured in City of Cupertino, CA's 2023 Consumer Confidence Report, spanning other, pfas ("forever chemicals"), and vocs & pesticides. 48 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.

Every value is transcribed from City of Cupertino, CA's 2023 Consumer Confidence Report — the annual drinking-water report every U.S. public water utility is required by federal law to publish. The original source document is archived and viewable on this site. A water-quality report covers an entire service area, not a single address.

Each U.S. public water utility publishes one Consumer Confidence Report per year, covering the prior calendar year's measurements. This page reflects the 2023 report; a new report will replace it once the utility publishes its next annual update.