Water Hardness in 48309
Rochester Hills, Michigan · Oakland 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 48309
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 |
|---|---|---|---|
Troy MI0006690 | surface water | 217 PPM Hard | |
Rochester Hills MI0000325 | surface water | 235 PPM Hard | |
Waterford Township MI0006910 | groundwater | 322 PPM Very HardUSGS estimate: 402 PPM | |
Southfield MI0006160 | surface water | 220 PPM Hard | |
Pontiac MI0005440 | surface water | 235 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 Rochester Hills, MI (48309).
Frequently Asked Questions
Is the water hard in Rochester Hills, MI (48309)?
The average water hardness in 48309 is 230 PPM (13.5 GPG), which is classified as hard.
Do I need a water softener in 48309?
With hardness of 230 PPM, a water softener is recommended for homes in 48309.
Is hard water in 48309 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 48309?
Zip code 48309 in Rochester Hills, Michigan is served by 25 water systems.
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