Water Hardness in 63367
Lake Saint Louis, Missouri · St. Charles County
Dataset updated March 9, 2026Matched to 8 water systemsTap readings can vary by utility zone, treatment, and plumbing. Methodology
How this ZIP reading is built
This ZIP reading is built from 8 matched water systems. When more than one system is matched, the displayed value is weighted toward larger known service populations when that data is available.
Hardness is a mineral-content reading, not a drinking-water safety rating. Use it for scale, appliance, and softener decisions; check your utility report or test your tap before sizing treatment equipment. See how we calculate local readings.
Water Systems Serving 63367
These are the systems matched to this ZIP code. The displayed ZIP value is weighted toward larger known service populations when population data is available.
| Water System | Source | Hardness | Pop. Served |
|---|---|---|---|
| Mo American St Louis St Charles Counties MO6010716 | surface water | 120 PPM Moderately HardUSGS estimate: 273 PPM | |
| St Charles County Pwsd 2 MO6024530 | surface water | 120 PPM Moderately HardUSGS estimate: 220 PPM | |
| St Charles Pws MO6010707 | surface water | 120 PPM Moderately HardUSGS estimate: 273 PPM | |
| St Peters Pws MO6010719 | surface water | 120 PPM Moderately HardUSGS estimate: 273 PPM | |
| Wentzville Pws MO6010849 | groundwater | 120 PPM Moderately HardUSGS estimate: 418 PPM |
Nearby Zip Codes
What This Means For You
Use this ZIP reading as a local planning estimate, not a final treatment specification. Hardness can vary by utility zone, seasonal blend, private well, and building plumbing. Confirm your tap reading with a utility report or home hardness test before sizing equipment.
Know your water hardness?
If you've tested your water or have your utility's CCR report, share your reading to help us improve accuracy for Lake Saint Louis, MO (63367).
Frequently Asked Questions
Is the water hard in Lake Saint Louis, MO (63367)?
The average water hardness in 63367 is 120 PPM (7 GPG), which is classified as moderately hard.
Do I need a water softener in 63367?
With hardness of 120 PPM, a water softener is worth considering for homes in 63367.
Is hard water in 63367 safe to drink?
Water hardness itself is a mineral-content reading, not a drinking-water safety rating. Calcium and magnesium are naturally occurring minerals, but you should check your utility's Consumer Confidence Report for contaminant and compliance information.
How many water systems serve 63367?
Zip code 63367 in Lake Saint Louis, Missouri is served by 8 water systems.
Learn More About Your Water
How to Test Water Hardness at Home
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10 min readPPM to GPG Converter + Water Hardness Scale Explained
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