Water Hardness in South Dakota
How to read the South Dakota results
State pages are screening and comparison hubs. They summarize ZIP, city, and water-system patterns so you can find the local page that best matches your home or utility.
Use the source coverage below to judge how much local confirmation a specific city or ZIP needs. The methodology page explains the source hierarchy, weighting, and limitations.
Data Source Coverage
ZIP-level source mix for South Dakota; higher direct and USGS coverage means less reliance on regional estimates.
In South Dakota, 21% of ZIPs use verified treated-water records, 14% use high-confidence USGS monitoring, and 65% use estimates that should be confirmed locally for treatment decisions.
What the Data Shows in South Dakota
Hard or very hard water is widespread in South Dakota, covering 82% of classified ZIPs.
South Dakota relies heavily on nearby, county, or state estimates: 65% of ZIPs use fallback values, so local testing matters more here than in states with stronger direct coverage.
Use the city table below to compare local results. For estimated locations or unusually high readings, confirm with your utility or a home hardness test before sizing treatment equipment.
ZIP Hardness Distribution
Treatment Takeaway
For many homes in South Dakota, hardness is high enough that scale buildup, fixture spotting, and appliance wear are realistic concerns. A local test is the best starting point before sizing a softener.
How to Use This Data
Because estimated ZIP values are common in South Dakota, use this page for screening and compare against a utility report or home test before buying equipment.
Useful South Dakota City Pages
Shortcuts to city pages backed by more ZIP-code or water-system data.
Cities With More Local Data
Prioritize cities with multiple ZIPs and systems, then use source badges on each city page to separate verified treated-water records from estimates.
Top 10 Hardest Water Cities
| # | City | Hardness |
|---|---|---|
| 1 | Ethan | Very Hard (1862 PPM) |
| 2 | Agency Village | Very Hard (1410 PPM) |
| 3 | New Effington | Very Hard (1410 PPM) |
| 4 | Hermosa | Very Hard (1390 PPM) |
| 5 | Lake Andes | Very Hard (1378 PPM) |
| 6 | Hot Springs | Very Hard (1358 PPM) |
| 7 | Wagner | Very Hard (1339 PPM) |
| 8 | Oelrichs | Very Hard (1163 PPM) |
| 9 | Dakota Dunes | Very Hard (952 PPM) |
| 10 | Oacoma | Very Hard (914 PPM) |
Top 10 Softest Water Cities
| # | City | Hardness |
|---|---|---|
| 1 | Isabel | Soft (15 PPM) |
| 2 | Timber Lake | Soft (17 PPM) |
| 3 | Morristown | Soft (28 PPM) |
| 4 | Bradley | Slightly Hard (68 PPM) |
| 5 | Claire City | Slightly Hard (68 PPM) |
| 6 | Lane | Slightly Hard (68 PPM) |
| 7 | Ortley | Slightly Hard (68 PPM) |
| 8 | Peever | Slightly Hard (68 PPM) |
| 9 | Raymond | Slightly Hard (68 PPM) |
| 10 | Mc Intosh | Slightly Hard (117 PPM) |
All Cities in South Dakota
City pages marked Estimated use fallback values and should be confirmed with local testing or utility data.