Hard water in Highland, CA
Reported by San Bernardino Valley WD · August 2025
- CA typical
- 121 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 24k grain
- Data
- Utility report
Highland water measures 123 mg/L (7.2 gpg) of hardness, hard by USGS standards. The number comes from San Bernardino Valley WD, dated August 2025. Reports for this system disagree, with values from 76 to 123 mg/L.
At 123 mg/L, Highland is close to the typical California figure of 121 mg/L. Of the 10 nearest cities we track, 8 have softer water and 2 have harder. The range nearby runs from 36 mg/L in Running Springs to 139 in Colton.
What 123 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 123 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.
3 people × 75 gallons a day × 7.2 gpg = 1,620 grains a day. A 24,000-grain unit regenerates about every 14 days.
EPA record for Highland's water system
No health-based violations since 2016
Serves about 109,608 people from groundwater.
- Health-based
- 0
- Monitoring or reporting
- 0
- Open now
- 0
TapWaterData ties Highland to this system. EPA's service-area records do not name Highland, so check the utility printed on your water bill.
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 Highland water hard?
Yes. It measures about 123 mg/L (7.2 grains per gallon), which the USGS classes as hard.
What is the water hardness in Highland in grains per gallon?
About 7.2 gpg. One grain per gallon equals 17.1 mg/L, so 123 mg/L divided by 17.1 gives 7.2.
What size water softener do I need in Highland?
For 3 people using 75 gallons each per day, 7.2 gpg works out to about 1,620 grains a day. A 24,000-grain softener covers that with a regeneration about every 14 days.
Has the Highland water system had EPA violations?
EPA records show no health-based violations for San Bernardino Valley WD since 2016.
Nearby cities
- Redlands111 mg/LModerately hard
- Mentone111 mg/LModerately hard
- Loma Linda99 mg/LModerately hard
- Running Springs36 mg/LSoft
- San Bernardino79 mg/LModerately hard
- Yucaipa108 mg/LModerately hard
- Lake Arrowhead56 mg/LSoft
- Colton139 mg/LHard
- Grand Terrace137 mg/LHard
- Muscoy72 mg/LModerately hard
Hardness data: TapWaterData US Water Hardness (utility report, August 4, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.