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City water profile

St. Thomas water quality

Compare local ZIP estimates, evidence quality, associated public systems, and compliance history for St. Thomas, North Dakota.

Median indexed hardness

304PPM

One indexed ZIP

Range 304–304 PPM

State comparison
68 PPM below
State hardness rank
#172 of 210
Matched utilities
1
Active health records
0

City summary

What the indexed records say

St. Thomas has 1 published ZIP profile across Pembina County. The indexed median is 304 PPM, compared with 372 PPM across North Dakota.

Among the 210 North Dakotacities with an indexed median, St. Thomas ranks #172from highest to lowest. Across all 226 state ZIP profiles, available estimates run from 170.5to 716 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. At least one estimate is marked low confidence, so observation distance and date deserve extra attention.

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
27.3 miles
Profiles with evidence
1/1

Confidence labels

High: 0Moderate: 0Low: 1

Observation window: Jul 2, 2018 to May 14, 2024.

ZIP directory

Water reports in St. Thomas

Open a ZIP for site-level provenance and measurements.

ZIP code

58276

Very Hard

304 PPM

Nearest site
27.3 mi
Confidence
Low

View full ZIP evidence →

Public water systems

Utilities associated with this city

St Thomas City Of

PWSID ND3400856

Groundwater
System population served
331
Last reported
Jun 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
Consumer Confidence RuleND3400856Oct 2, 2022Resolved
Lead and Copper RuleND3400856Sep 28, 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 St. Thomas

Is the water hard?

The indexed city median is 304 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.