How hard is the water in Imperial, CA?

Tap water hardness
94mg/L
5.5gpg
Moderately hard

Reported by Imperial, City of · November 2022

CA typical
121 mg/L
EPA health violations since 2016
8
Softener for 3 people
24k grain
Data
Utility report

Imperial water measures 94 mg/L (5.5 gpg) of hardness, moderately hard by USGS standards. The number comes from Imperial, City of, dated November 2022.

Imperial on the hardness scale, with nearby cities
060120180240300360+CA typical 121Heber: 53 mg/LHeber 53San Diego Country Estates: 85 mg/LSan Diego Country Estates 85Coachella: 99 mg/LCoachella 99Indio: 100 mg/LIndio 100Mecca: 113 mg/LMecca 113La Quinta: 113 mg/LLa Quinta 113El Centro: 150 mg/LEl Centro 150Brawley: 150 mg/LBrawley 150Calexico: 174 mg/LCalexico 174Alpine: 209 mg/LAlpine 209Imperial 94mg/L as calcium carbonate060120180240300360+CA 121Heber: 53 mg/LHeber 53Coachella: 99 mg/LCoachella 99Mecca: 113 mg/LMecca 113El Centro: 150 mg/LEl Centro 150Brawley: 150 mg/LBrawley 150Calexico: 174 mg/LCalexico 17494 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 94 mg/L, Imperial is 27 mg/L below the typical California figure of 121. Of the 10 nearest cities we track, 2 have softer water and 8 have harder. The range nearby runs from 53 mg/L in Heber to 209 in Alpine.

What 94 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 Imperial

3 people × 75 gallons a day × 5.5 gpg = 1,242 grains a day. A 24,000-grain unit regenerates about every 19 days.

Size it for your household

EPA record for Imperial's water system

Imperial, City of · PWSID CA1310006

8 health-based violations since 2016

Serves about 22,102 people from surface water.

Health-based
8
Monitoring or reporting
4
Open now
0
20162017201820192020202120222023202420252026Lead and Copper RuleSurface Water Treatment RuleTotal trihalomethanes (TTHM)'16'18'20'22'24'26Lead and Copper RuleSurface Water Treatment RuleTotal trihalomethanes (TTHM)
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 sampling12024Resolved
Surface Water Treatment Rulefiltration and disinfection12018Resolved
Total trihalomethanes (TTHM)a disinfection byproduct62016–2017Resolved

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 Imperial water hard?

Somewhat. It measures about 94 mg/L (5.5 grains per gallon), which the USGS classes as moderately hard.

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

About 5.5 gpg. One grain per gallon equals 17.1 mg/L, so 94 mg/L divided by 17.1 gives 5.5.

What size water softener do I need in Imperial?

For 3 people using 75 gallons each per day, 5.5 gpg works out to about 1,242 grains a day. A 24,000-grain softener covers that with a regeneration about every 19 days.

Has the Imperial water system had EPA violations?

EPA records show 8 health-based violations for Imperial, City of since 2016, involving Lead and Copper Rule, Surface Water Treatment Rule, Total trihalomethanes (TTHM). There were also 4 monitoring or reporting violations, which are about late or missing tests and notices.

Nearby cities

All 515 cities in California

Hardness data: TapWaterData US Water Hardness (utility report, November 16, 2022), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.