Hard water in Pleasanton, CA

Tap water hardness
161mg/L
9.4gpg
HardReports range 80–161

Reported by City of Pleasanton · September 2025

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

Tap water in Pleasanton has about 161 mg/L of hardness, which is 9.4 grains per gallon. On the USGS scale that counts as hard. The number comes from City of Pleasanton, dated September 2025. Reports for this system disagree, with values from 80 to 161 mg/L.

Pleasanton on the hardness scale, with nearby cities
060120180240300360+CA typical 121Fairview: 33 mg/LFairview 33Cherryland: 33 mg/LCherryland 33Camino Tassajara: 34 mg/LCamino Tassajara 34Blackhawk: 34 mg/LBlackhawk 34Castro Valley: 34 mg/LCastro Valley 34Danville: 34 mg/LDanville 34San Ramon: 44 mg/LSan Ramon 44Union City: 65 mg/LUnion City 65Fremont: 65 mg/LFremont 65Livermore: 94 mg/LLivermore 94Pleasanton 161mg/L as calcium carbonate060120180240300360+CA 121Fairview: 33 mg/LFairview 33Camino Tassajara: 34 mg/LCamino Tas. 34Blackhawk: 34 mg/LBlackhawk 34San Ramon: 44 mg/LSan Ramon 44Union City: 65 mg/LUnion City 65Livermore: 94 mg/LLivermore 94161 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 161 mg/L, Pleasanton is 40 mg/L above the typical California figure of 121. None of the 10 nearest cities we track has harder water. The range nearby runs from 33 mg/L in Fairview to 94 in Livermore.

What 161 mg/L means at home

Expect white crust on faucets and showerheads, plus spots on dishes that come out of the dishwasher.

Kettles collect scale quickly. Water heaters build up sediment at the bottom of the tank, which makes them work harder over time.

Soap and detergent need a little more to lather, and soap scum shows up in the tub.

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

At 161 mg/L most of the trouble is scale, and only a few things deal with it.

Ion-exchange water softener

The standard whole-house fix. It swaps calcium and magnesium for sodium or potassium and needs salt plus a drain. Size it with the calculator below.

Salt-free conditioner

No salt and no drain line. It changes how minerals form scale instead of removing them, so water still tests hard.

Reverse osmosis or carbon filter

Under-sink reverse osmosis removes minerals from drinking water only. Plain carbon filters improve taste but do not soften.

Softener size for Pleasanton

3 people × 75 gallons a day × 9.4 gpg = 2,120 grains a day. A 24,000-grain unit regenerates about every 11 days.

Size it for your household

EPA record for Pleasanton's water system

City of Pleasanton · PWSID CA0110008

No health-based violations since 2016

Serves about 76,689 people from surface water.

Health-based
0
Monitoring or reporting
0
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 Pleasanton water hard?

Yes. It measures about 161 mg/L (9.4 grains per gallon), which the USGS classes as hard.

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

About 9.4 gpg. One grain per gallon equals 17.1 mg/L, so 161 mg/L divided by 17.1 gives 9.4.

What size water softener do I need in Pleasanton?

For 3 people using 75 gallons each per day, 9.4 gpg works out to about 2,120 grains a day. A 24,000-grain softener covers that with a regeneration about every 11 days.

Has the Pleasanton water system had EPA violations?

EPA records show no health-based violations for City of Pleasanton since 2016.

Nearby cities

All 515 cities in California

Hardness data: TapWaterData US Water Hardness (utility report, September 26, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.