How hard is the water in Coalinga, CA?

Tap water hardness
118mg/L
6.9gpg
Moderately hard

Reported by Coalinga-City · April 2023

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

Tap water in Coalinga has about 118 mg/L of hardness, which is 6.9 grains per gallon. On the USGS scale that counts as moderately hard. The number comes from Coalinga-City, dated April 2023.

Coalinga on the hardness scale, with nearby cities
060120180240300360+CA typical 121Hanford: 11 mg/LHanford 11Mendota: 17 mg/LMendota 17Lemoore: 26 mg/LLemoore 26Atascadero: 39 mg/LAtascadero 39Corcoran: 64 mg/LCorcoran 64Kingsburg: 91 mg/LKingsburg 91Lemoore Station: 100 mg/LLemoore Station 100Firebaugh: 121 mg/LFirebaugh 121Selma: 202 mg/LSelma 202Greenfield: 227 mg/LGreenfield 227Coalinga 118mg/L as calcium carbonate060120180240300360+CA 121Hanford: 11 mg/LHanford 11Mendota: 17 mg/LMendota 17Lemoore: 26 mg/LLemoore 26Atascadero: 39 mg/LAtascadero 39Corcoran: 64 mg/LCorcoran 64Lemoore Station: 100 mg/LLemoore St. 100118 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

At 118 mg/L, Coalinga is close to the typical California figure of 121 mg/L. Of the 10 nearest cities we track, 7 have softer water and 3 have harder. The range nearby runs from 11 mg/L in Hanford to 227 in Greenfield.

What 118 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 Coalinga

3 people × 75 gallons a day × 6.9 gpg = 1,553 grains a day. A 24,000-grain unit regenerates about every 15 days.

Size it for your household

EPA record for Coalinga's water system

Coalinga-City · PWSID CA1010004

No health-based violations since 2016

Serves about 17,277 people from surface water.

Health-based
0
Monitoring or reporting
1
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 Coalinga water hard?

Somewhat. It measures about 118 mg/L (6.9 grains per gallon), which the USGS classes as moderately hard.

What is the water hardness in Coalinga in grains per gallon?

About 6.9 gpg. One grain per gallon equals 17.1 mg/L, so 118 mg/L divided by 17.1 gives 6.9.

What size water softener do I need in Coalinga?

For 3 people using 75 gallons each per day, 6.9 gpg works out to about 1,553 grains a day. A 24,000-grain softener covers that with a regeneration about every 15 days.

Has the Coalinga water system had EPA violations?

EPA records show no health-based violations for Coalinga-City since 2016. There were also 1 monitoring or reporting violation, which are about late or missing tests and notices.

Nearby cities

All 515 cities in California

Hardness data: TapWaterData US Water Hardness (utility report, April 4, 2023), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.