How hard is the water in Dinuba, CA?

Tap water hardness
92mg/L
5.3gpg
Moderately hard

Reported by Dinuba, City of · September 2022

CA typical
121 mg/L
EPA health violations since 2016
1
Softener for 3 people
24k grain
Data
Utility report

The water in Dinuba carries roughly 92 mg/L of dissolved calcium and magnesium, or 5.3 grains per gallon. That is moderately hard water. The number comes from Dinuba, City of, dated September 2022.

Dinuba on the hardness scale, with nearby cities
060120180240300360+CA typical 121Hanford: 11 mg/LHanford 11Tulare: 37 mg/LTulare 37Clovis: 59 mg/LClovis 59Visalia: 74 mg/LVisalia 74Kingsburg: 91 mg/LKingsburg 91Sunnyside: 167 mg/LSunnyside 167Orosi: 170 mg/LOrosi 170Reedley: 202 mg/LReedley 202Selma: 202 mg/LSelma 202Sanger: 202 mg/LSanger 202Dinuba 92mg/L as calcium carbonate060120180240300360+CA 121Visalia: 74 mg/LVisalia 74Kingsburg: 91 mg/LKingsburg 91Orosi: 170 mg/LOrosi 170Reedley: 202 mg/LReedley 202Selma: 202 mg/LSelma 202Sanger: 202 mg/LSanger 20292 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Dinuba sits 29 mg/L below the typical California figure of 121. Of the 10 nearest cities we track, 5 have softer water and 5 have harder. The range nearby runs from 11 mg/L in Hanford to 202 in Reedley.

What 92 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 Dinuba

3 people × 75 gallons a day × 5.3 gpg = 1,204 grains a day. A 24,000-grain unit regenerates about every 19 days.

Size it for your household

EPA record for Dinuba's water system

Dinuba, City of · PWSID CA5410002

1 health-based violation since 2016

Serves about 27,641 people from groundwater.

Health-based
1
Monitoring or reporting
1
Open now
2
20162017201820192020202120222023202420252026Lead and Copper Rule'16'18'20'22'24'26Lead and Copper Rule
Each dot is one health-based violation, placed at the start of its compliance period.
Contaminant or ruleViolationsPeriodStatus
Lead and Copper Rulecorrosion control and lead sampling120241 open

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 Dinuba water hard?

Somewhat. It measures about 92 mg/L (5.3 grains per gallon), which the USGS classes as moderately hard.

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

About 5.3 gpg. One grain per gallon equals 17.1 mg/L, so 92 mg/L divided by 17.1 gives 5.3.

What size water softener do I need in Dinuba?

For 3 people using 75 gallons each per day, 5.3 gpg works out to about 1,204 grains a day. A 24,000-grain softener covers that with a regeneration about every 19 days.

Has the Dinuba water system had EPA violations?

EPA records show 1 health-based violation for Dinuba, City of since 2016, involving Lead and Copper Rule. 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, September 16, 2022), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.