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City water profile

Fond Du Lac water quality

Compare local ZIP estimates, evidence quality, associated public systems, and compliance history for Fond Du Lac, Wisconsin.

Median indexed hardness

336PPM

2 indexed ZIPs

Range 336–336 PPM

State comparison
48 PPM above
State hardness rank
#108 of 479
Matched utilities
6
Active health records
0

City summary

What the indexed records say

Fond Du Lac has 2 published ZIP profiles across Fond Du Lac County. The indexed median is 336 PPM, compared with 288 PPM across Wisconsin.

Among the 479 Wisconsincities with an indexed median, Fond Du Lac ranks #108from highest to lowest. Across all 556 state ZIP profiles, available estimates run from 41.3to 467 PPM.

The 336–336 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
26.5 miles
Profiles with evidence
2/2

Confidence labels

High: 0Moderate: 1Low: 1

Observation window: Aug 2, 2016 to Sep 9, 2024.

ZIP directory

Water reports in Fond Du Lac

Open a ZIP for site-level provenance and measurements.

ZIP code

54935

Very Hard

336 PPM

Nearest site
26.5 mi
Confidence
Low

View full ZIP evidence →

ZIP code

54937

Very Hard

336 PPM

Nearest site
23 mi
Confidence
Moderate

View full ZIP evidence →

Public water systems

Utilities associated with this city

Fond Du Lac Waterworks

PWSID WI4200469

Groundwater
System population served
44,678
Last reported
May 29, 2026

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

Ashwood Grove Edgewater

PWSID WI4200485

Groundwater
System population served
1,046
Last reported
May 29, 2026

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

Fond Du Lac Tn Water Utility

PWSID WI4200429

Groundwater
System population served
980
Last reported
May 29, 2026

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

Woodland Park

PWSID WI4200798

Groundwater
System population served
66
Last reported
May 29, 2026

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

Mary Hill Park Sanitary Dist

PWSID WI4200465

Groundwater
System population served
65
Last reported
May 29, 2026

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

Colonial Gardens Homes

PWSID WI4200484

Groundwater
System population served
48
Last reported
May 29, 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
Revised Total Coliform RuleWI4200484Dec 1, 2024Resolved
Revised Total Coliform RuleWI4200484Nov 1, 2024Resolved
Public NoticeWI4200469Oct 17, 2024Resolved
LEAD AND COPPER RULE REVISIONSWI4200469Oct 17, 2024Resolved · health-based
Public NoticeWI4200429Oct 17, 2024Resolved
LEAD AND COPPER RULE REVISIONSWI4200429Oct 17, 2024Resolved
LEAD AND COPPER RULE REVISIONSWI4200429Oct 17, 2024Resolved · health-based
Public NoticeWI4200429Oct 17, 2024Unaddressed
LEAD AND COPPER RULE REVISIONSWI4200465Oct 17, 2024Resolved
Revised Total Coliform RuleWI4200484Oct 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 Fond Du Lac

Is the water hard?

The indexed city median is 336 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.