City water profile
Compare local ZIP estimates, evidence quality, associated public systems, and compliance history for Rockford, Illinois.
Median indexed hardness
394PPM
8 indexed ZIPs
Range 373.5–396 PPM
City summary
Rockford has 8 published ZIP profiles across Winnebago County. The indexed median is 394 PPM, compared with 285 PPM across Illinois.
Among the 913 Illinoiscities with an indexed median, Rockford ranks #16from highest to lowest. Across all 1,065 state ZIP profiles, available estimates run from 115to 408 PPM.
The 373.5–396 PPM range shows how much the available ZIP estimates vary within the city label.
Hardness distribution
8 of 8 ZIP profiles have a hardness estimate. Bars count ZIP profiles, not households or laboratory samples.
Evidence quality
Confidence labels
Observation window: Aug 3, 2016 to Aug 21, 2023.
ZIP directory
Open a ZIP for site-level provenance and measurements.
ZIP code
394 PPM
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ZIP code
375 PPM
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ZIP code
396 PPM
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ZIP code
394 PPM
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ZIP code
394 PPM
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ZIP code
394 PPM
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ZIP code
373.5 PPM
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ZIP code
394 PPM
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Public water systems
PWSID IL2010300
The system names this served city; Census place overlap links the city to this ZCTA.
PWSID IL2015400
The system names this served city; Census place overlap links the city to this ZCTA.
PWSID IL2015345
The system names this served city; Census place overlap links the city to this ZCTA.
PWSID IL2015100
The system names this served city; Census place overlap links the city to this ZCTA.
PWSID IL2015425
The system names this served city; Census place overlap links the city to this ZCTA.
PWSID IL2015050
The system names this served city; Census place overlap links the city to this ZCTA.
Compliance history
No active health-based violation appears among the associated systems in the represented EPA reporting quarter. This does not mean every contaminant was tested at every tap.
| Record | System | Period | Status |
|---|---|---|---|
| Revised Total Coliform Rule | IL2015345 | Mar 1, 2026 | Archived |
| Chlorine | IL2015345 | Mar 1, 2026 | Archived |
| Lead and Copper Rule | IL2015425 | Oct 1, 2025 | Unaddressed |
| LEAD AND COPPER RULE REVISIONS | IL2015100 | Jul 2, 2025 | Unaddressed |
| LEAD AND COPPER RULE REVISIONS | IL2015100 | Oct 17, 2024 | Resolved |
| LEAD AND COPPER RULE REVISIONS | IL2015100 | Oct 17, 2024 | Resolved · health-based |
| Total Haloacetic Acids (HAA5) | IL2010300 | Oct 1, 2024 | Resolved |
| Consumer Confidence Rule | IL2015425 | Jul 1, 2024 | Resolved |
| Public Notice | IL2015345 | Feb 9, 2024 | Resolved |
| Public Notice | IL2015345 | Feb 9, 2024 | Resolved |
Practical next steps
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Questions people ask
The indexed city median is 394 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.