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City water profile

Callao water quality

Compare local ZIP estimates, evidence quality, associated public systems, and compliance history for Callao, Missouri.

Median indexed hardness

191PPM

One indexed ZIP

Range 191–191 PPM

State comparison
45 PPM below
State hardness rank
#400 of 504
Matched utilities
1
Active health records
0

City summary

What the indexed records say

Callao has 1 published ZIP profile across Macon County. The indexed median is 191 PPM, compared with 236 PPM across Missouri.

Among the 504 Missouricities with an indexed median, Callao ranks #400from highest to lowest. Across all 556 state ZIP profiles, available estimates run from 38.3to 483 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
15.6 miles
Profiles with evidence
1/1

Confidence labels

High: 0Moderate: 1Low: 0

Observation window: Jan 11, 2016 to May 13, 2026.

ZIP directory

Water reports in Callao

Open a ZIP for site-level provenance and measurements.

ZIP code

63534

Very Hard

191 PPM

Nearest site
15.6 mi
Confidence
Moderate

View full ZIP evidence →

Public water systems

Utilities associated with this city

Callao Pws

PWSID MO2010125

Surface water
System population served
248
Last reported
Jun 16, 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
Consumer Confidence RuleMO2010125Jul 1, 2025Unaddressed
Revised Total Coliform RuleMO2010125Jun 1, 2025Resolved
Lead and Copper RuleMO2010125Oct 1, 2024Resolved
Revised Total Coliform RuleMO2010125Mar 1, 2024Resolved
Public NoticeMO2010125Dec 14, 2023Resolved
Public NoticeMO2010125Oct 1, 2023Resolved
Revised Total Coliform RuleMO2010125Apr 1, 2023Resolved
Revised Total Coliform RuleMO2010125Aug 1, 2022Resolved
Consumer Confidence RuleMO2010125Jul 1, 2022Resolved
Total Haloacetic Acids (HAA5)MO2010125Jan 1, 2022Resolved

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 Callao

Is the water hard?

The indexed city median is 191 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.