How hard is the water in Manteca, CA?

Tap water hardness
75mg/L
4.4gpg
Moderately hardReports range 28–75

Reported by Manteca, City of · December 2024

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

Tap water in Manteca has about 75 mg/L of hardness, which is 4.4 grains per gallon. On the USGS scale that counts as moderately hard. The number comes from Manteca, City of, dated December 2024. Reports for this system disagree, with values from 28 to 75 mg/L.

Manteca on the hardness scale, with nearby cities
060120180240300360+CA typical 121Country Club: 10 mg/LCountry Club 10Ripon: 28 mg/LRipon 28Escalon: 28 mg/LEscalon 28Salida: 44 mg/LSalida 44West Modesto: 44 mg/LWest Modesto 44Modesto: 44 mg/LModesto 44Mountain House: 61 mg/LMountain House 61Ceres: 66 mg/LCeres 66Tracy: 67 mg/LTracy 67Riverbank: 196 mg/LRiverbank 196Manteca 75mg/L as calcium carbonate060120180240300360+CA 121Country Club: 10 mg/LCountry Cl. 10Ripon: 28 mg/LRipon 28Escalon: 28 mg/LEscalon 28Salida: 44 mg/LSalida 44Tracy: 67 mg/LTracy 67Riverbank: 196 mg/LRiverbank 19675 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 75 mg/L, Manteca is 46 mg/L below the typical California figure of 121. Of the 10 nearest cities we track, 9 have softer water and 1 has harder. The range nearby runs from 10 mg/L in Country Club to 196 in Riverbank.

What 75 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 Manteca

3 people × 75 gallons a day × 4.4 gpg = 990 grains a day. A 24,000-grain unit regenerates about every 24 days.

Size it for your household

EPA record for Manteca's water system

Manteca, City of · PWSID CA3910005

No health-based violations since 2016

Serves about 84,928 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 Manteca water hard?

Somewhat. It measures about 75 mg/L (4.4 grains per gallon), which the USGS classes as moderately hard.

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

About 4.4 gpg. One grain per gallon equals 17.1 mg/L, so 75 mg/L divided by 17.1 gives 4.4.

What size water softener do I need in Manteca?

For 3 people using 75 gallons each per day, 4.4 gpg works out to about 990 grains a day. A 24,000-grain softener covers that with a regeneration about every 24 days.

Has the Manteca water system had EPA violations?

EPA records show no health-based violations for Manteca, City of 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, December 8, 2024), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.