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City water profile

Twin Falls water quality

Compare local ZIP estimates, evidence quality, associated public systems, and compliance history for Twin Falls, Idaho.

Median indexed hardness

226PPM

One indexed ZIP

Range 226–226 PPM

State comparison
58 PPM above
State hardness rank
#11 of 67
Matched utilities
1
Active health records
0

City summary

What the indexed records say

Twin Falls has 1 published ZIP profile across Twin Falls County. The indexed median is 226 PPM, compared with 168 PPM across Idaho.

Among the 67 Idahocities with an indexed median, Twin Falls ranks #11from highest to lowest. Across all 78 state ZIP profiles, available estimates run from 22.2to 339 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
15.1 miles
Profiles with evidence
1/1

Confidence labels

High: 0Moderate: 1Low: 0

Observation window: Jun 13, 2016 to Jul 21, 2021.

ZIP directory

Water reports in Twin Falls

Open a ZIP for site-level provenance and measurements.

ZIP code

83301

Very Hard

226 PPM

Nearest site
15.1 mi
Confidence
Moderate

View full ZIP evidence →

Public water systems

Utilities associated with this city

Twin Falls City Of

PWSID ID5420058

Groundwater
System population served
56,121
Last reported
Jun 26, 2026

A municipal system, in-state city, and served county all agree with this Census 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
Revised Total Coliform RuleID5420058Feb 1, 2026Archived
ChlorineID5420058Feb 1, 2026Archived
NitrateID5420058Jan 1, 2023Resolved
Lead and Copper RuleID5420058Jul 1, 2022Resolved
Lead and Copper RuleID5420058Jul 1, 2022Resolved
NitrateID5420058Jan 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 Twin Falls

Is the water hard?

The indexed city median is 226 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.