Source document
Helena, OK 2020 Consumer Confidence Report
The original annual drinking-water report. Every number on the Helena, OK water quality page is pulled from this document.
The Helena, OK figures for 2020 come from EPA's national Safe Drinking Water database (SDWIS / ECHO) — not a single utility-published PDF. Every value on the Helena, OK 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