Source document
Hillside, IL 1997 Consumer Confidence Report
The original annual drinking-water report. Every number on the Hillside, IL water quality page is pulled from this document.
The Hillside, IL figures for 1997 come from EPA's national Safe Drinking Water database (SDWIS / ECHO) — not a single utility-published PDF. Every value on the Hillside, 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