O'Fallon, MO Water Report

O'Fallon's water is hard and busy. Depending on who bills you, you're looking at 6-10 grains of hardness on treated city water and up to 15-20 grains on raw county and well water - that's the chalky white scale crusting your faucets, the spots on your glasses, the soap that won't lather, and the water heater that dies years early eating through your energy bill. Add chlorine plus Missouri River organics and you get a chemical taste and smell at the tap, with disinfection byproducts (TTHMs) measured as high as 40 ppb. Radium runs 40-66x the health guideline, arsenic and atrazine show up too, and forever-chemical PFOA was detected in the county's federal sampling. Your skin and hair pay for it daily - hard water leaves a mineral film that dries skin out and leaves hair dull and straw-like no matter what shampoo you buy.

On a private well in O'Fallon: St. Charles private wells (Missouri River alluvium + deep bedrock) commonly fight: iron and manganese (orange/brown staining, metallic taste, clogged aerators - the most common MO complaint), hydrogen sulfide "rotten-egg" smell with black slime and sulfur bacteria, very hard water (15-25+ gpg), elevated nitrates in shallow wells near row-crop ag and septic (infant-safety risk - must be tested per well), coliform/E. coli in shallow or poorly sealed wells, and naturally occurring radium/gross alpha/uranium in deep bedrock wells. The former Weldon Spring uranium/explosives site has documented uranium, radium and thorium groundwater contamination that Missouri regulators warned in 2021 "isn't improving" - a real, cited reason for western/southwestern county well owners to test and treat. Free/low-cost coliform, E. coli and iron-bacteria testing is available through the MO State Public Health Lab.