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City water profile

Fullerton water quality

Compare local ZIP estimates, evidence quality, associated public systems, and compliance history for Fullerton, California.

Median indexed hardness

183PPM

4 indexed ZIPs

Range 181–187.5 PPM

State comparison
6 PPM below
State hardness rank
#146 of 242
Matched utilities
1
Active health records
0

City summary

What the indexed records say

Fullerton has 4 published ZIP profiles across Orange County. The indexed median is 183 PPM, compared with 189 PPM across California.

Among the 242 Californiacities with an indexed median, Fullerton ranks #146from highest to lowest. Across all 678 state ZIP profiles, available estimates run from 3.3to 728.5 PPM.

The 181–187.5 PPM range shows how much the available ZIP estimates vary within the city label.

Hardness distribution

How local ZIP estimates compare

Soft0 ZIPs
Moderately hard0 ZIPs
Hard0 ZIPs
Very hard4 ZIPs

4 of 4 ZIP profiles have a hardness estimate. Bars count ZIP profiles, not households or laboratory samples.

Evidence quality

Distance, dates, and confidence

Median nearest distance
13.6 miles
Profiles with evidence
4/4

Confidence labels

High: 0Moderate: 4Low: 0

Observation window: Jan 6, 2016 to May 14, 2026.

ZIP directory

Water reports in Fullerton

Open a ZIP for site-level provenance and measurements.

ZIP code

92831

Very Hard

181 PPM

Nearest site
14.2 mi
Confidence
Moderate

View full ZIP evidence →

ZIP code

92832

Very Hard

184 PPM

Nearest site
13.6 mi
Confidence
Moderate

View full ZIP evidence →

ZIP code

92833

Very Hard

187.5 PPM

Nearest site
12 mi
Confidence
Moderate

View full ZIP evidence →

ZIP code

92835

Very Hard

182 PPM

Nearest site
12.4 mi
Confidence
Moderate

View full ZIP evidence →

Public water systems

Utilities associated with this city

City Of Fullerton

PWSID CA3010010

Surface water
System population served
139,461
Last reported
Jun 22, 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 Fullerton

Is the water hard?

The indexed city median is 183 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.