Source document
Rock Island, IL 2011 Consumer Confidence Report
The original annual drinking-water report. Every number on the Rock Island, IL water quality page is pulled from this document.
The Rock Island, IL figures for 2011 come from EPA's national Safe Drinking Water database (SDWIS / ECHO) — not a single utility-published PDF. Every value on the Rock Island, IL water quality page is transcribed from that public dataset, and you can verify it against the same source below.
View the source dataset ↗https://echo.epa.gov/tools/data-downloads/sdwa-download-summary