How hard is the water in Twentynine Palms, CA?

Tap water hardness
111mg/L
6.5gpg
Moderately hardCounty estimate

County estimate from 4,331 water samples in San Bernardino County · July 2026

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

Water samples from around Twentynine Palms put hardness at about 111 mg/L (6.5 gpg), which would be moderately hard on the USGS scale. Treat this as a rough guide: it is the median of 4,331 samples taken across San Bernardino County, mostly wells and streams, not a test of Twentynine Palms's treated tap water.

Twentynine Palms on the hardness scale, with nearby cities
060120180240300360+CA typical 121Joshua Tree: 70 mg/LJoshua Tree 70Coachella: 99 mg/LCoachella 99Indio: 100 mg/LIndio 100Yucca Valley: 110 mg/LYucca Valley 110Thousand Palms: 113 mg/LThousand Palms 113Desert Palms: 113 mg/LDesert Palms 113Bermuda Dunes: 113 mg/LBermuda Dunes 113Cathedral City: 138 mg/LCathedral City 138Garnet: 213 mg/LGarnet 213Desert Hot Springs: 213 mg/LDesert Hot Springs 213Twentynine Palms 111mg/L as calcium carbonate060120180240300360+CA 121Joshua Tree: 70 mg/LJoshua Tree 70Yucca Valley: 110 mg/LYucca Vall. 110Thousand Palms: 113 mg/LThousand P. 113Desert Palms: 113 mg/LDesert Pal. 113Garnet: 213 mg/LGarnet 213Desert Hot Springs: 213 mg/LDesert Hot. 213111 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 111 mg/L, Twentynine Palms is close to the typical California figure of 121 mg/L. Of the 10 nearest cities we track, 4 have softer water and 6 have harder. The range nearby runs from 70 mg/L in Joshua Tree to 213 in Garnet.

What 111 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 Twentynine Palms

3 people × 75 gallons a day × 6.5 gpg = 1,460 grains a day. A 24,000-grain unit regenerates about every 16 days.

Size it for your household

EPA record for Twentynine Palms's water system

Twentynine Palms Water District · PWSID CA3610049

No health-based violations since 2016

Serves about 18,795 people from groundwater.

Health-based
0
Monitoring or reporting
0
Open now
0

EPA lists this system as serving Twentynine Palms.

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 Twentynine Palms water hard?

Somewhat. It measures about 111 mg/L (6.5 grains per gallon), which the USGS classes as moderately hard.

What is the water hardness in Twentynine Palms in grains per gallon?

About 6.5 gpg. One grain per gallon equals 17.1 mg/L, so 111 mg/L divided by 17.1 gives 6.5.

What size water softener do I need in Twentynine Palms?

For 3 people using 75 gallons each per day, 6.5 gpg works out to about 1,460 grains a day. A 24,000-grain softener covers that with a regeneration about every 16 days.

Has the Twentynine Palms water system had EPA violations?

EPA records show no health-based violations for Twentynine Palms Water District since 2016.

Nearby cities

All 515 cities in California

Hardness data: TapWaterData US Water Hardness (county estimate, July 4, 2026), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.