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City water profile

Waterloo water quality

Compare local ZIP estimates, evidence quality, associated public systems, and compliance history for Waterloo, Iowa.

Median indexed hardness

275PPM

3 indexed ZIPs

Range 269–274.5 PPM

State comparison
6 PPM below
State hardness rank
#358 of 683
Matched utilities
1
Active health records
0

City summary

What the indexed records say

Waterloo has 3 published ZIP profiles across Black Hawk County. The indexed median is 275 PPM, compared with 281 PPM across Iowa.

Among the 683 Iowacities with an indexed median, Waterloo ranks #358from highest to lowest. Across all 723 state ZIP profiles, available estimates run from 182to 834 PPM.

The 269–274.5 PPM range shows how much the available ZIP estimates vary within the city label.

Hardness distribution

How local ZIP estimates compare

Soft0 ZIPs
Moderately hard0 ZIPs
Hard0 ZIPs
Very hard3 ZIPs

3 of 3 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 miles
Profiles with evidence
3/3

Confidence labels

High: 0Moderate: 3Low: 0

Observation window: Feb 9, 2016 to Mar 3, 2026.

ZIP directory

Water reports in Waterloo

Open a ZIP for site-level provenance and measurements.

ZIP code

50701

Very Hard

274.5 PPM

Nearest site
5 mi
Confidence
Moderate

View full ZIP evidence →

ZIP code

50702

Very Hard

274.5 PPM

Nearest site
4.4 mi
Confidence
Moderate

View full ZIP evidence →

ZIP code

50703

Very Hard

269 PPM

Nearest site
8.5 mi
Confidence
Moderate

View full ZIP evidence →

Public water systems

Utilities associated with this city

Waterloo Water Works

PWSID IA0790074

Groundwater
System population served
69,504
Last reported
Jun 17, 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.

No violation records are included in the current lookback window.

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 Waterloo

Is the water hard?

The indexed city median is 275 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.