Water Hardness in 63664
Potosi, Missouri · Washington County
Dataset updated March 9, 2026Matched to 3 water systemsTap readings can vary by utility zone, treatment, and plumbing. Methodology
How this ZIP reading is built
This ZIP reading is built from 3 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 63664
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 |
|---|---|---|---|
Potosi Pws MO6010659 | groundwater | 206 PPM Hard | |
Potosi East MO6069096 | groundwater | 206 PPM Hard | |
Washington County Pwsd 1 MO6024633 | groundwater | 206 PPM 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.
Hard Water - Treatment Recommended
Your water is hard. Scale buildup is likely affecting your plumbing and appliances, reducing their lifespan and efficiency. A water softener is recommended to protect your home.
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 Potosi, MO (63664).
Frequently Asked Questions
Is the water hard in Potosi, MO (63664)?
The average water hardness in 63664 is 206 PPM (12 GPG), which is classified as hard.
Do I need a water softener in 63664?
With hardness of 206 PPM, a water softener is recommended for homes in 63664.
Is hard water in 63664 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 63664?
Zip code 63664 in Potosi, Missouri is served by 3 water systems.
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