Water Hardness in 62204
Washington Park, Illinois · St. Clair County
Dataset updated March 9, 2026Matched to 4 water systemsTap readings can vary by utility zone, treatment, and plumbing. Methodology
How this ZIP reading is built
This ZIP reading is built from 4 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 62204
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 |
|---|---|---|---|
Il American-East St Louis IL1635040 | surface water | 207 PPM Hard | |
O Fallon IL1631100 | surface water | 399 PPM Very Hard | |
Cahokia Heights IL1635000 | surface water | 212 PPM Hard | |
Caseyville IL1630250 | surface water | 501 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.
Very Hard Water - Treatment Strongly Recommended
Your water is very hard. Without treatment, you can expect significant scale buildup in pipes and appliances, higher energy bills from reduced water heater efficiency, and persistent issues with skin and hair dryness.
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 Washington Park, IL (62204).
Frequently Asked Questions
Is the water hard in Washington Park, IL (62204)?
The average water hardness in 62204 is 270 PPM (15.8 GPG), which is classified as very hard.
Do I need a water softener in 62204?
With hardness of 270 PPM, a water softener is recommended for homes in 62204.
Is hard water in 62204 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 62204?
Zip code 62204 in Washington Park, Illinois is served by 4 water systems.
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