City water profile
Compare local ZIP estimates, evidence quality, associated public systems, and compliance history for Rapid City, South Dakota.
Median indexed hardness
615PPM
3 indexed ZIPs
Range 525.5–615 PPM
City summary
Rapid City has 3 published ZIP profiles across Pennington County. The indexed median is 615 PPM, compared with 516 PPM across South Dakota.
Among the 222 South Dakotacities with an indexed median, Rapid City ranks #73from highest to lowest. Across all 246 state ZIP profiles, available estimates run from 20.5to 1330 PPM.
The 525.5–615 PPM range shows how much the available ZIP estimates vary within the city label.
Hardness distribution
3 of 3 ZIP profiles have a hardness estimate. Bars count ZIP profiles, not households or laboratory samples.
Evidence quality
Confidence labels
Observation window: Jan 5, 2016 to Mar 18, 2026.
ZIP directory
Open a ZIP for site-level provenance and measurements.
Public water systems
PWSID SD4600406
EPA SDWIS explicitly lists this ZIP in the system's served geography.
PWSID SD4600862
EPA SDWIS explicitly lists this ZIP in the system's served geography.
PWSID SD4602379
EPA SDWIS explicitly lists this ZIP in the system's served geography.
PWSID SD4600875
EPA SDWIS explicitly lists this ZIP in the system's served geography.
PWSID SD4602094
EPA SDWIS explicitly lists this ZIP in the system's served geography.
PWSID SD4602189
EPA SDWIS explicitly lists this ZIP in the system's served geography.
PWSID SD4602363
EPA SDWIS explicitly lists this ZIP in the system's served geography.
PWSID SD4602260
EPA SDWIS explicitly lists this ZIP in the system's served geography.
PWSID SD4602295
EPA SDWIS explicitly lists this ZIP in the system's served geography.
PWSID SD4602356
EPA SDWIS explicitly lists this ZIP in the system's served geography.
PWSID SD4600263
EPA SDWIS explicitly lists this ZIP in the system's served geography.
PWSID SD4600264
EPA SDWIS explicitly lists this ZIP in the system's served geography.
PWSID SD4600271
EPA SDWIS explicitly lists this ZIP in the system's served geography.
PWSID SD4600910
EPA SDWIS explicitly lists this ZIP in the system's served geography.
PWSID SD4600948
EPA SDWIS explicitly lists this ZIP in the system's served geography.
PWSID SD4600627
EPA SDWIS explicitly lists this ZIP in the system's served geography.
PWSID SD4602203
EPA SDWIS explicitly lists this ZIP in the system's served geography.
PWSID SD4602272
EPA SDWIS explicitly lists this ZIP in the system's served geography.
PWSID SD4602261
EPA SDWIS explicitly lists this ZIP in the system's served geography.
PWSID SD4600265
EPA SDWIS explicitly lists this ZIP in the system's served geography.
PWSID SD4600274
EPA SDWIS explicitly lists this ZIP in the system's served geography.
PWSID SD4602301
EPA SDWIS explicitly lists this ZIP in the system's served geography.
PWSID SD4600403
EPA SDWIS explicitly lists this ZIP in the system's served geography.
Compliance history
2 unique active health-based records appear among associated systems. This does not mean every contaminant was tested at every tap.
| Record | System | Period | Status |
|---|---|---|---|
| Revised Total Coliform Rule | SD4602209 | Jan 1, 2026 | Archived |
| Combined Radium (-226 and -228) | SD4600403 | Jan 1, 2026 | Archived · health-based |
| Gross Alpha, Excl. Radon and U | SD4600403 | Jan 1, 2026 | Archived · health-based |
| Stage 1 Disinfectants and Disinfection Byproducts Rule | SD4600403 | Nov 12, 2025 | Unaddressed · health-based |
| Combined Radium (-226 and -228) | SD4600403 | Oct 1, 2025 | Archived · health-based |
| Stage 1 Disinfectants and Disinfection Byproducts Rule | SD4600420 | Jul 7, 2025 | Unaddressed · health-based |
| Consumer Confidence Rule | SD4600862 | Jul 1, 2025 | Unaddressed |
| Revised Total Coliform Rule | SD4600050 | Jul 1, 2025 | Resolved |
| Combined Radium (-226 and -228) | SD4600403 | Jul 1, 2025 | Archived · health-based |
| Stage 1 Disinfectants and Disinfection Byproducts Rule | SD4602301 | Feb 1, 2025 | Resolved · health-based |
Practical next steps
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Questions people ask
The indexed city median is 615 PPM. Open the ZIP report to verify the distance and confidence behind that estimate.
Compliance history is utility-wide and cannot guarantee conditions at every tap. Check current notices and test when address-specific evidence is needed.
Choose treatment only after confirming the problem at the property. A softener targets hardness; contaminant treatment requires a matching, verified performance claim.