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City water profile

Knoxville water quality

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

Median indexed hardness

333PPM

One indexed ZIP

Range 332.5–332.5 PPM

State comparison
52 PPM above
State hardness rank
#179 of 683
Matched utilities
5
Active health records
0

City summary

What the indexed records say

Knoxville has 1 published ZIP profile across Marion County. The indexed median is 333 PPM, compared with 281 PPM across Iowa.

Among the 683 Iowacities with an indexed median, Knoxville ranks #179from highest to lowest. Across all 723 state ZIP profiles, available estimates run from 182to 834 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
15 miles
Profiles with evidence
1/1

Confidence labels

High: 0Moderate: 1Low: 0

Observation window: May 30, 2017 to Aug 1, 2024.

ZIP directory

Water reports in Knoxville

Open a ZIP for site-level provenance and measurements.

ZIP code

50138

Very Hard

332.5 PPM

Nearest site
15 mi
Confidence
Moderate

View full ZIP evidence →

Public water systems

Utilities associated with this city

Knoxville Water Works

PWSID IA6342036

Groundwater
System population served
8,400
Last reported
Jun 17, 2026

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

Marion Co. Rural Water District

PWSID IA6342711

Groundwater
System population served
5,687
Last reported
Jun 17, 2026

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

Wheel Estates Mhc

PWSID IA6342301

Groundwater
System population served
315
Last reported
Jun 17, 2026

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

Colonial Terrace Mhp Llc

PWSID IA6342601

Groundwater
System population served
250
Last reported
Jun 17, 2026

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

Southshore Heights

PWSID IA6342308

Groundwater
System population served
138
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.

RecordSystemPeriodStatus
Public NoticeIA6342711Jan 21, 2025Unaddressed
NitriteIA6342711Oct 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 Knoxville

Is the water hard?

The indexed city median is 333 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.