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City water profile

Walla Walla water quality

Compare local ZIP estimates, evidence quality, associated public systems, and compliance history for Walla Walla, Washington.

Median indexed hardness

30PPM

One indexed ZIP

Range 29.6–29.6 PPM

State comparison
74 PPM below
State hardness rank
#126 of 133
Matched utilities
1
Active health records
0

City summary

What the indexed records say

Walla Walla has 1 published ZIP profile across Walla Walla County. The indexed median is 30 PPM, compared with 104 PPM across Washington.

Among the 133 Washingtoncities with an indexed median, Walla Walla ranks #126from highest to lowest. Across all 189 state ZIP profiles, available estimates run from 20.6to 238 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

Soft1 ZIP
Moderately hard0 ZIPs
Hard0 ZIPs
Very hard0 ZIPs

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
11.4 miles
Profiles with evidence
1/1

Confidence labels

High: 0Moderate: 1Low: 0

Observation window: Jan 19, 2016 to Apr 20, 2026.

ZIP directory

Water reports in Walla Walla

Open a ZIP for site-level provenance and measurements.

ZIP code

99362

Soft

29.6 PPM

Nearest site
11.4 mi
Confidence
Moderate

View full ZIP evidence →

Public water systems

Utilities associated with this city

Walla Walla Water Division

PWSID WA5392500

Surface water
System population served
42,959
Last reported
Jun 19, 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
NitrateWA5392500Jan 1, 2023Resolved
DinosebWA5392500Oct 1, 2022Resolved
2,4,5-TPWA5392500Oct 1, 2022Resolved
PentachlorophenolWA5392500Oct 1, 2022Resolved
DalaponWA5392500Oct 1, 2022Resolved
PicloramWA5392500Oct 1, 2022Resolved
DalaponWA5392500Jul 1, 2022Resolved
DinosebWA5392500Jul 1, 2022Resolved
PentachlorophenolWA5392500Jul 1, 2022Resolved
2,4,5-TPWA5392500Jul 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 Walla Walla

Is the water hard?

The indexed city median is 30 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.