Water Hardness in 63131
Des Peres, Missouri · St. Louis County
Dataset updated March 9, 2026Matched to 25 water systemsTap readings can vary by utility zone, treatment, and plumbing. Methodology
How this ZIP reading is built
This ZIP reading is built from 25 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 63131
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 | |
Kirkwood Pws MO6010430 | surface water | 120 PPM Moderately HardUSGS estimate: 270 PPM | |
Terre Du Lac MO4036059 | groundwater | 270 PPM Very Hard | |
Indian Hills Utilities Operating Company MO6036052 | groundwater | 270 PPM Very Hard | |
Lake Sherwood Subd MO6036039 | groundwater | 270 PPM Very Hard |
Nearby Zip Codes
What This Means For You
Recommendations are based on the displayed ZIP hardness reading. Confirm your tap reading before sizing or buying treatment equipment.
Moderately Hard Water
Your water is moderately hard. You're likely seeing scale buildup on fixtures, spotty dishes, and may notice dry skin or hair. A water softener or conditioner can help.
Recommended Products
Learn more: Do I Need a Water Softener? | Salt-Based vs Salt-Free | Size Calculator | How to Test Your Water
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 Des Peres, MO (63131).
Frequently Asked Questions
Is the water hard in Des Peres, MO (63131)?
The average water hardness in 63131 is 122 PPM (7.1 GPG), which is classified as moderately hard.
Do I need a water softener in 63131?
With hardness of 122 PPM, a water softener is worth considering for homes in 63131.
Is hard water in 63131 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 63131?
Zip code 63131 in Des Peres, Missouri is served by 25 water systems.
Learn More About Your Water
Do You Need a Water Softener? (Based on Your Water Hardness)
A data-driven guide to help you decide if a water softener is worth the investment based on your actual water hardness level.
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Salt-based softeners remove hardness minerals. Salt-free conditioners prevent scale but don't soften. Here's how to choose based on your water hardness level.
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We tested KDF, Vitamin C, and carbon shower filters for hard water. Here are the filters that actually reduce mineral buildup on hair and skin.
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