Water Hardness in Chico, CA

Q: Do I need a water softener in Chico, CA?

With a citywide weighted average hardness of 198 PPM, a water softener is recommended for homes in Chico. A water softener is recommended to protect your plumbing and appliances.

Q: How many water systems serve Chico, CA?

Chico, California has 12 matched water systems across 1 zip code.

California · 1 zip codes · 12 matched water systems

36 PPM

2.1 GPG

Soft

0Soft60120180300+

Verified — State Lab Tested

City avg (weighted): 198 PPM

Dataset updated March 9, 202612 matched water systems in the city rollupIndividual systems and ZIPs can differ. Methodology

System used for this reading

Thermalito Water & Sewer Dist

CA0410008

Water source: surface water

Source year: 2024

Serves: 12,136

USGS environmental estimate: 155 PPM

Source context

How this city reading is built

This city reading is a weighted rollup across 12 matched water systems and 1 ZIP code. Citywide readings are useful for comparison, but individual utility zones and ZIPs can differ.

Source basis

3 verified treated-water sources

12 matched systems total for this city; treated-water reports are prioritized when available.

Water source profile

Primarily groundwater

Groundwater commonly picks up calcium and magnesium after contact with rock and soil. This profile is weighted by known population served across matched systems.

Data recency

Report years 2023-2024

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 Chico

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

12 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.

Water System	Source	Hardness	Pop. Served	Data Source
Cal-Water Service Co.-Chico CA0410002	groundwater	250 PPM Very Hard	114,925	High Confidence — USGS Monitoring
South Feather W&P - Miners Ranch CA0410006	surface water	155 PPM Moderately Hard	22,664	High Confidence — USGS Monitoring
Thermalito Water & Sewer Dist CA0410008	surface water	36 PPM Soft USGS estimate: 155 PPM	12,136	Verified — State Lab Tested(2024)
Cal-Water Service Co.-Oroville CA0410005	surface water	35 PPM Soft USGS estimate: 192 PPM	11,106	Verified — State Lab Tested(2024)
Del Oro Water Co.-Paradise Pines CA0410011	surface water	105 PPM Slightly Hard	10,940	Estimated — County Avg

Cal-Water Service Co.-Chico

CA0410002

Very Hard

250 PPMgroundwater114,925 servedHigh Confidence — USGS Monitoring

South Feather W&P - Miners Ranch

CA0410006

Moderately Hard

155 PPMsurface water22,664 servedHigh Confidence — USGS Monitoring

Thermalito Water & Sewer Dist

CA0410008

Soft

36 PPMsurface water12,136 servedVerified — State Lab Tested

Source water: 155 PPM

Cal-Water Service Co.-Oroville

CA0410005

Soft

35 PPMsurface water11,106 servedVerified — State Lab Tested

Source water: 192 PPM

Del Oro Water Co.-Paradise Pines

CA0410011

Slightly Hard

105 PPMsurface water10,940 servedEstimated — County Avg

Showing the first 5 systems. Expand to review all matched systems.

Zip Codes in Chico, CA

95928198

What This Means For You

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

Your Water Is Soft

Your water hardness is in the soft range. You likely don't need a water softener. Enjoy your naturally soft 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 Chico, CA.

Submit Your Data

Frequently Asked Questions

How hard is the water in Chico, CA?

The citywide weighted average water hardness in Chico, CA is 198 PPM (11.6 GPG), classified as hard. This is based on 12 matched water systems. The gauge highlights Thermalito Water & Sewer Dist, a verified treated-water system, because individual systems can differ from the citywide average.

Do I need a water softener in Chico, CA?

With a citywide average hardness of 198 PPM, a water softener is recommended for homes in Chico. Confirm your tap reading before sizing equipment.

Is hard water in Chico, 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 Chico, CA?

Chico, California is served by 12 matched water systems across 1 zip code.

Learn More About Your Water

Water Hardness Scale: PPM and GPG Chart

Use the USGS water hardness scale to compare PPM, GPG, and mg/L levels from soft to very hard water.

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How to Test Water Hardness at Home

Compare free lookups, soap tests, test strips, liquid drop kits, and lab tests for measuring water hardness.

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