How hard is the water in Chino Hills, CA?

Tap water hardness
81mg/L
4.8gpg
Moderately hardReports range 13–81

Reported by Chino Hills, City of · April 2025

CA typical
121 mg/L
EPA health violations since 2016
0
Softener for 3 people
24k grain
Data
Utility report

The water in Chino Hills carries roughly 81 mg/L of dissolved calcium and magnesium, or 4.8 grains per gallon. That is moderately hard water. The number comes from Chino Hills, City of, dated April 2025. Reports for this system disagree, with values from 13 to 81 mg/L.

Chino Hills on the hardness scale, with nearby cities
060120180240300360+CA typical 121Yorba Linda: 48 mg/LYorba Linda 48Ontario: 104 mg/LOntario 104Eastvale: 114 mg/LEastvale 114Pomona: 138 mg/LPomona 138Diamond Bar: 153 mg/LDiamond Bar 153Rowland Heights: 160 mg/LRowland Heights 160Montclair: 166 mg/LMontclair 166Brea: 191 mg/LBrea 191Walnut: 210 mg/LWalnut 210Anaheim: 274 mg/LAnaheim 274Chino Hills 81mg/L as calcium carbonate060120180240300360+CA 121Yorba Linda: 48 mg/LYorba Linda 48Eastvale: 114 mg/LEastvale 114Pomona: 138 mg/LPomona 138Diamond Bar: 153 mg/LDiamond Bar 153Brea: 191 mg/LBrea 191Anaheim: 274 mg/LAnaheim 27481 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Chino Hills sits 40 mg/L below the typical California figure of 121. Of the 10 nearest cities we track, 1 has softer water and 9 have harder. The range nearby runs from 48 mg/L in Yorba Linda to 274 in Anaheim.

What 81 mg/L means at home

You may see faint white spots on glasses and shower doors after the water dries.

Scale builds up slowly. A kettle or coffee maker needs descaling now and then, maybe every few months.

Hardness is not a health problem, and EPA sets no limit for it. It is a matter of scale and soap.

What to do about it

Optional. Plenty of households at this level live with it and descale the kettle now and then.

Water softener

Worth a look if spots on glass bother you, or if your tankless water heater manual asks for softer water.

Carbon filter

Improves taste and removes chlorine. It leaves calcium and magnesium in place.

Softener size for Chino Hills

3 people × 75 gallons a day × 4.8 gpg = 1,071 grains a day. A 24,000-grain unit regenerates about every 22 days.

Size it for your household

EPA record for Chino Hills's water system

Chino Hills, City of · PWSID CA3610036

No health-based violations since 2016

Serves about 76,314 people from surface water.

Health-based
0
Monitoring or reporting
0
Open now
0

Health-based means a contaminant above its legal limit or a missed treatment step. Monitoring and reporting violations are late or missing tests and notices. Source: EPA ECHO, 2026Q3 export, violations with periods starting 2016 or later. Full EPA record.

Questions

Is Chino Hills water hard?

Somewhat. It measures about 81 mg/L (4.8 grains per gallon), which the USGS classes as moderately hard.

What is the water hardness in Chino Hills in grains per gallon?

About 4.8 gpg. One grain per gallon equals 17.1 mg/L, so 81 mg/L divided by 17.1 gives 4.8.

What size water softener do I need in Chino Hills?

For 3 people using 75 gallons each per day, 4.8 gpg works out to about 1,071 grains a day. A 24,000-grain softener covers that with a regeneration about every 22 days.

Has the Chino Hills water system had EPA violations?

EPA records show no health-based violations for Chino Hills, City of since 2016.

Nearby cities

All 515 cities in California

Hardness data: TapWaterData US Water Hardness (utility report, April 15, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.