Warrenton, MO Water Report
Warren County · Grade F · Extremely hard · 16.0 grains per gallon
Grade F Extremely hard
Anything over 7 gpg is considered hard. Warrenton runs extremely hard.
Warrenton runs on 100% deep groundwater and the City does NOT soften it - so your tap pours out very hard 16-grain water that crusts white scale on faucets and showerheads, kills soap lather, leaves spots on dishes, makes laundry stiff, and quietly shortens the life of your water heater and appliances. That same hardness leaves skin dry and itchy and hair flat and filmy. On top of it, the water is chlorinated, which creates cancer-linked disinfection byproducts (TTHMs run 116x the EWG health guideline), and it carries naturally-occurring radium from the rock under Warren County at roughly 41x the EWG guideline. It is legal and meets federal standards - but legal does not mean it matches the latest health science, and it definitely does not feel good on your body or your plumbing.
On a private well in Warrenton: Private wells are unregulated (no CCR, no mandated testing) so owners have no idea what's in their water. Regional pattern, test to confirm any specific home: very hard water (15-25+ gpg on limestone/dolomite), iron and manganese causing orange/brown staining and metallic taste, hydrogen sulfide "rotten-egg" sulfur smell in deeper carbonate/sandstone wells, naturally elevated radium/gross alpha in deep wells (can exceed the 5 pCi/L MCL with nobody watching), nitrates from ag/septic in shallow row-crop and river-bottom wells, coliform/E. coli bacteria in shallow or flood-prone Missouri River bottom wells, and salty/brackish TDS in deep bottom wells near the freshwater-saline transition zone running through the county.
Data: verified municipal + lab reports for Warrenton, compiled 2026. (confidence: verified)