Source document
Contra Costa Water District, CA 2023 Consumer Confidence Report
The original annual drinking-water report. Every number on the Contra Costa Water District, CA water quality page is pulled from this document.
The Contra Costa Water District, CA figures for 2023 come from California's SDWIS Electronic Data Transfer (EDT) library — not a single utility-published PDF. Every value on the Contra Costa Water District, CA water quality page is transcribed from that public dataset, and you can verify it against the same source below.
View the source dataset ↗https://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/EDTlibrary.html