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Water Hardness in 57744

Hermosa, South Dakota · Custer County

1390 PPM
81.3 GPG
Very Hard
0Soft60120180300+
High Confidence - USGS Monitoring

Dataset updated March 9, 2026Matched to 4 water systemsTap readings can vary by utility zone, treatment, and plumbing. Methodology

Source context

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.

Source basis
1 USGS-backed source
4 matched systems total for this ZIP; USGS monitoring is used where treated-water reports are unavailable.
Water source profile
Primarily groundwater
Groundwater commonly picks up calcium and magnesium after contact with rock and soil. This profile is weighted by known population served across matched systems.
Data recency
March 9, 2026
Dataset rebuilt March 9, 2026; individual utility reporting years can vary.

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 57744

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.

4 water systems
PWSID is the public water system identifier. Data Source shows whether the hardness value comes from a treated-water report, USGS monitoring, or a local estimate; source year is shown when available.
Hermosa-Old System
SD4600154
Very Hard
1523 PPMgroundwater420 servedEstimated - Nearby Data
Hermosa Water Users Association
SD4602180
Very Hard
1523 PPMgroundwater108 servedEstimated - Nearby Data
Heartland Country Ranchettes
SD4602235
Very Hard
597 PPMgroundwater95 servedHigh Confidence - USGS Monitoring
North Hermosa Wud
SD4600329
Very Hard
1523 PPMgroundwater40 servedEstimated - Nearby Data

Nearby Zip Codes

5773876457703150577251505775115057722267577011505770215057767150

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.

MethodologyData sourcesHow 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 Hermosa, SD (57744).

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Frequently Asked Questions

Is the water hard in Hermosa, SD (57744)?

The average water hardness in 57744 is 1390 PPM (81.3 GPG), which is classified as very hard.

Do I need a water softener in 57744?

With hardness of 1390 PPM, a water softener is recommended for homes in 57744.

Is hard water in 57744 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 57744?

Zip code 57744 in Hermosa, South Dakota is served by 4 water systems.

Learn More About Your Water

How to Test Water Hardness at Home

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Water Hardness Scale: PPM and GPG Chart

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Well Water Hardness: Why It's Usually Hard & How to Treat It

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