Source document
Berwyn, IL 2019 Consumer Confidence Report
The original annual drinking-water report. Every number on the Berwyn, IL water quality page is pulled from this document.
The Berwyn, IL figures for 2019 come from EPA's national Safe Drinking Water database (SDWIS / ECHO) — not a single utility-published PDF. Every value on the Berwyn, 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