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City water profile

Flat Rock water quality

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

Median indexed hardness

321PPM

One indexed ZIP

Range 321–321 PPM

State comparison
36 PPM above
State hardness rank
#177 of 913
Matched utilities
1
Active health records
0

City summary

What the indexed records say

Flat Rock has 1 published ZIP profile across Crawford County. The indexed median is 321 PPM, compared with 285 PPM across Illinois.

Among the 913 Illinoiscities with an indexed median, Flat Rock ranks #177from highest to lowest. Across all 1,065 state ZIP profiles, available estimates run from 115to 408 PPM.

Because only one ZIP is represented, the city median and range are the same local estimate. It should not be read as multiple independent samples across the community. 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 hard1 ZIP

1 of 1 ZIP profiles have a hardness estimate. Bars count ZIP profiles, not households or laboratory samples.

Evidence quality

Distance, dates, and confidence

Median nearest distance
48.1 miles
Profiles with evidence
1/1

Confidence labels

High: 0Moderate: 0Low: 1

Observation window: Aug 8, 2019 to Aug 12, 2025.

ZIP directory

Water reports in Flat Rock

Open a ZIP for site-level provenance and measurements.

ZIP code

62427

Very Hard

321 PPM

Nearest site
48.1 mi
Confidence
Low

View full ZIP evidence →

Public water systems

Utilities associated with this city

Flat Rock

PWSID IL0330050

Groundwater
System population served
325
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

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.

RecordSystemPeriodStatus
LEAD AND COPPER RULE REVISIONSIL0330050Jul 2, 2025Unaddressed
Consumer Confidence RuleIL0330050Jul 1, 2025Unaddressed
Consumer Confidence RuleIL0330050Jul 1, 2024Unaddressed
Consumer Confidence RuleIL0330050Jul 1, 2024Resolved

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 Flat Rock

Is the water hard?

The indexed city median is 321 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.