Water Hardness in 57783
Spearfish, South Dakota · Lawrence 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 57783
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 |
|---|---|---|---|
| Spearfish SD4600311 | groundwater | 218 PPM Hard | |
| Mountain Plains 2 Homeowners Assoc SD4602169 | groundwater | 218 PPM Hard | |
| Saint Onge Sewer & Water Co SD4600287 | groundwater | 218 PPM Hard | |
| Lantern Estates SD4600315 | groundwater | 218 PPM Hard | |
| Walnut Park SD4600316 | groundwater | 218 PPM Hard |
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 Spearfish, SD (57783).
Frequently Asked Questions
Is the water hard in Spearfish, SD (57783)?
The average water hardness in 57783 is 226 PPM (13.2 GPG), which is classified as hard.
Do I need a water softener in 57783?
With hardness of 226 PPM, a water softener is recommended for homes in 57783.
Is hard water in 57783 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 57783?
Zip code 57783 in Spearfish, South Dakota is served by 25 water systems.
Learn More About Your Water
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