WH

Water Hardness in Cerritos, CA

California · 3 zip codes · 50 matched water systems

112 PPM
6.5 GPG
Slightly Hard
0Soft60120180300+
Verified — State Lab Tested

City avg (weighted): 173 PPM

Dataset updated March 9, 202650 matched water systems in the city rollupIndividual systems and ZIPs can differ. Methodology

System used for this reading
Los Angeles-City, Dept. Of Water & Power
CA1910067
Water source: surface water
Source year: 2024
Serves: 3,875,566
USGS environmental estimate: 189 PPM
Source context

How this city reading is built

This city reading is a weighted rollup across 50 matched water systems and 3 ZIP codes. Citywide readings are useful for comparison, but individual utility zones and ZIPs can differ.

Source basis
18 verified treated-water sources
50 matched systems total for this city; treated-water reports are prioritized when available.
Water source profile
Primarily surface water
Surface-water hardness can shift with reservoirs, runoff, season, and treatment. This profile is weighted by known population served across matched systems.
Data recency
Report years 2023-2025
Dataset rebuilt March 9, 2026; individual utility reporting years can vary.

Hardness is a mineral-content reading, not a drinking-water safety rating. Use it for scale, appliance, and softener decisions; check your utility report or test your tap before sizing treatment equipment. See how we calculate local readings.

Water Systems in Cerritos

These systems are matched to Cerritos, CA. Citywide readings are useful for comparison, but the system serving a specific address may differ from the city average.

50 water systems
PWSID is the public water system identifier. Data Source shows whether the hardness value comes from a treated-water report, USGS monitoring, or a local estimate; source year is shown when available.
Los Angeles-City, Dept. Of Water & Power
CA1910067
Slightly Hard
112 PPMsurface water3,875,566 servedVerified — State Lab Tested
Source water: 189 PPM
Long Beach Utilities Department
CA1910065
Slightly Hard
103 PPMsurface water466,772 servedHigh Confidence — USGS Monitoring
Irvine Ranch Water District
CA3010092
Moderately Hard
140 PPMsurface water444,800 servedVerified — State Lab Tested
Source water: 247 PPM
City Of Anaheim
CA3010001
Moderately Hard
150 PPMsurface water348,593 servedHigh Confidence — USGS Monitoring
City Of Santa Ana
CA3010038
Moderately Hard
150 PPMsurface water310,539 servedHigh Confidence — USGS Monitoring
Showing the first 5 systems. Expand to review all matched systems.

Zip Codes in Cerritos, CA

What This Means For You

Recommendations are based on the displayed hardness reading. Confirm your tap reading before sizing or buying treatment equipment.

Slightly Hard Water

Your water is slightly hard. You may notice minor spotting on dishes or a slight film on faucets. A water softener is optional but can improve water quality.

Recommended Products

Learn more: Do I Need a Water Softener? | Salt-Based vs Salt-Free | How to Test Your Water

Know your water hardness?

If you've tested your water or have your utility's CCR report, share your reading to help us improve accuracy for Cerritos, CA.

Submit Your Data

Frequently Asked Questions

How hard is the water in Cerritos, CA?

The citywide weighted average water hardness in Cerritos, CA is 173 PPM (10.1 GPG), classified as moderately hard. This is based on 50 matched water systems. The gauge highlights Los Angeles-City, Dept. Of Water & Power, a verified treated-water system, because individual systems can differ from the citywide average.

Do I need a water softener in Cerritos, CA?

With a citywide average hardness of 173 PPM, a water softener is worth considering for homes in Cerritos. Confirm your tap reading before sizing equipment.

Is hard water in Cerritos, CA safe to drink?

Water hardness itself is a mineral-content reading, not a drinking-water safety rating. Calcium and magnesium are naturally occurring minerals, but you should check your utility's Consumer Confidence Report for contaminant and compliance information.

How many water systems serve Cerritos, CA?

Cerritos, California is served by 50 matched water systems across 3 zip codes.

Learn More About Your Water