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City water profile

St. Peters water quality

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

Median indexed hardness

257PPM

One indexed ZIP

Range 256.5–256.5 PPM

State comparison
21 PPM above
State hardness rank
#198 of 504
Matched utilities
1
Active health records
0

City summary

What the indexed records say

St. Peters has 1 published ZIP profile across St. Charles County. The indexed median is 257 PPM, compared with 236 PPM across Missouri.

Among the 504 Missouricities with an indexed median, St. Peters ranks #198from 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
16.6 miles
Profiles with evidence
1/1

Confidence labels

High: 0Moderate: 1Low: 0

Observation window: Jan 6, 2016 to Jun 9, 2026.

ZIP directory

Water reports in St. Peters

Open a ZIP for site-level provenance and measurements.

ZIP code

63376

Very Hard

256.5 PPM

Nearest site
16.6 mi
Confidence
Moderate

View full ZIP evidence →

Public water systems

Utilities associated with this city

St Peters Pws

PWSID MO6010719

Surface water
System population served
52,575
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.

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 St. Peters

Is the water hard?

The indexed city median is 257 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.