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City water profile

Delafield water quality

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

Median indexed hardness

417PPM

One indexed ZIP

Range 417–417 PPM

State comparison
129 PPM above
State hardness rank
#13 of 479
Matched utilities
10
Active health records
0

City summary

What the indexed records say

Delafield has 1 published ZIP profile across Waukesha County. The indexed median is 417 PPM, compared with 288 PPM across Wisconsin.

Among the 479 Wisconsincities with an indexed median, Delafield ranks #13from highest to lowest. Across all 556 state ZIP profiles, available estimates run from 41.3to 467 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.

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
5.7 miles
Profiles with evidence
1/1

Confidence labels

High: 0Moderate: 1Low: 0

Observation window: May 31, 2017 to Aug 8, 2024.

ZIP directory

Water reports in Delafield

Open a ZIP for site-level provenance and measurements.

ZIP code

53018

Very Hard

417 PPM

Nearest site
5.7 mi
Confidence
Moderate

View full ZIP evidence →

Public water systems

Utilities associated with this city

Delafield Square

PWSID WI2685812

Groundwater
System population served
587
Last reported
May 29, 2026

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

Nashotah House

PWSID WI2682512

Groundwater
System population served
350
Last reported
May 29, 2026

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

St Johns Northwestern Academies

PWSID WI2680761

Groundwater
System population served
340
Last reported
May 29, 2026

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

Delafield Waterworks

PWSID WI2684642

Groundwater
System population served
300
Last reported
May 29, 2026

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

Arbors

PWSID WI2682795

Groundwater
System population served
280
Last reported
May 29, 2026

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

Lake Country Apartments

PWSID WI2682229

Groundwater
System population served
84
Last reported
May 29, 2026

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

Apartments Of Stoneridge

PWSID WI2682761

Groundwater
System population served
75
Last reported
May 29, 2026

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

Knollcrest

PWSID WI2681104

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.

Cambridge Place Of Delafield

PWSID WI2686325

Groundwater
System population served
50
Last reported
May 29, 2026

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

Delafield Lakes 402

PWSID WI2686101

Groundwater
System population served
40
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 RuleWI2686359Apr 1, 2025Resolved
Lead and Copper RuleWI2682512Jan 1, 2025Resolved
Lead and Copper RuleWI2686359Jan 1, 2025Resolved
Public NoticeWI2680761Oct 17, 2024Unaddressed
Public NoticeWI2680761Oct 17, 2024Unaddressed
LEAD AND COPPER RULE REVISIONSWI2680761Oct 17, 2024Resolved
LEAD AND COPPER RULE REVISIONSWI2680761Oct 17, 2024Resolved · health-based
LEAD AND COPPER RULE REVISIONSWI2682795Oct 17, 2024Resolved
Public NoticeWI2682795Oct 17, 2024Unaddressed
Public NoticeWI2682795Oct 17, 2024Unaddressed

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 Delafield

Is the water hard?

The indexed city median is 417 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.