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City water profile

Windsor water quality

Compare local ZIP estimates, evidence quality, associated public systems, and compliance history for Windsor, Illinois.

Median indexed hardness

302PPM

2 indexed ZIPs

Range 288–315 PPM

State comparison
17 PPM above
State hardness rank
#344 of 913
Matched utilities
2
Active health records
1

City summary

What the indexed records say

Windsor has 2 published ZIP profiles across Mercer County and Shelby County. The indexed median is 302 PPM, compared with 285 PPM across Illinois.

Among the 913 Illinoiscities with an indexed median, Windsor ranks #344from highest to lowest. Across all 1,065 state ZIP profiles, available estimates run from 115to 408 PPM.

The 288–315 PPM range shows how much the available ZIP estimates vary within the city label. At least one estimate is marked low confidence, so observation distance and date deserve extra attention.

Hardness distribution

How local ZIP estimates compare

Soft0 ZIPs
Moderately hard0 ZIPs
Hard0 ZIPs
Very hard2 ZIPs

2 of 2 ZIP profiles have a hardness estimate. Bars count ZIP profiles, not households or laboratory samples.

Evidence quality

Distance, dates, and confidence

Median nearest distance
33.2 miles
Profiles with evidence
2/2

Confidence labels

High: 0Moderate: 0Low: 2

Observation window: Feb 16, 2016 to Jun 3, 2026.

ZIP directory

Water reports in Windsor

Open a ZIP for site-level provenance and measurements.

ZIP code

61465

Very Hard

288 PPM

Nearest site
25.5 mi
Confidence
Low

View full ZIP evidence →

ZIP code

61957

Very Hard

315 PPM

Nearest site
33.2 mi
Confidence
Low

View full ZIP evidence →

Public water systems

Utilities associated with this city

Windsor

PWSID IL1730550

Surface water
System population served
1,200
Last reported
May 27, 2026

The system names this served city; Census place overlap links the city to this ZCTA.

New Windsor

PWSID IL1310500

Groundwater
System population served
740
Last reported
May 27, 2026

The system names this served city; Census place overlap links the city to this ZCTA.

Compliance history

What EPA records show

1 unique active health-based record appears among associated systems. This does not mean every contaminant was tested at every tap.

RecordSystemPeriodStatus
Public NoticeIL1310500Aug 22, 2025Unaddressed
LEAD AND COPPER RULE REVISIONSIL1310500Jul 2, 2025Unaddressed
Consumer Confidence RuleIL1310500Jul 1, 2025Unaddressed
LEAD AND COPPER RULE REVISIONSIL1310500Oct 17, 2024Unaddressed
LEAD AND COPPER RULE REVISIONSIL1310500Oct 17, 2024Unaddressed · health-based
Public NoticeIL1310500Oct 11, 2024Unaddressed
Lead and Copper RuleIL1310500Oct 1, 2023Resolved
Public NoticeIL1730550Feb 17, 2023Resolved
Total Haloacetic Acids (HAA5)IL1730550Jan 1, 2023Resolved
TTHMIL1730550Jan 1, 2023Resolved

Practical next steps

Move from index to evidence

  1. 1. Open your ZIP. Check distance, dates, confidence, and the associated utility.
  2. 2. Read the current CCR. Confirm source water, detections, limits, ranges, and notices.
  3. 3. Test the tap when needed. Confirm health concerns or treatment sizing with the right method.

Questions people ask

About water in Windsor

Is the water hard?

The indexed city median is 302 PPM. Open the ZIP report to verify the distance and confidence behind that estimate.

Is the tap water safe?

Compliance history is utility-wide and cannot guarantee conditions at every tap. Check current notices and test when address-specific evidence is needed.

Do I need treatment?

Choose treatment only after confirming the problem at the property. A softener targets hardness; contaminant treatment requires a matching, verified performance claim.