Source document
Hecker, IL 1993 Consumer Confidence Report
The original annual drinking-water report. Every number on the Hecker, IL water quality page is pulled from this document.
The Hecker, IL figures for 1993 come from EPA's national Safe Drinking Water database (SDWIS / ECHO) — not a single utility-published PDF. Every value on the Hecker, 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