Hard water in Calexico, CA
Reported by Calexico, City of · March 2023
- CA typical
- 121 mg/L
- EPA health violations since 2016
- 2
- Softener for 3 people
- 24k grain
- Data
- Utility report
Calexico water measures 174 mg/L (10.2 gpg) of hardness, hard by USGS standards. The number comes from Calexico, City of, dated March 2023.
Calexico sits 53 mg/L above the typical California figure of 121. Of the 10 nearest cities we track, 8 have softer water and 2 have harder. The range nearby runs from 53 mg/L in Heber to 289 in Jamul.
What 174 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 174 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 × 10.2 gpg = 2,290 grains a day. A 24,000-grain unit regenerates about every 10 days.
EPA record for Calexico's water system
2 health-based violations since 2016
Serves about 40,357 people from surface water.
- Health-based
- 2
- Monitoring or reporting
- 1
- Open now
- 2
| Contaminant or rule | Violations | Period | Status |
|---|---|---|---|
| Lead and Copper Rulecorrosion control and lead sampling | 1 | 2024 | 1 open |
| Total trihalomethanes (TTHM)a disinfection byproduct | 1 | 2019 | Resolved |
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 Calexico water hard?
Yes. It measures about 174 mg/L (10.2 grains per gallon), which the USGS classes as hard.
What is the water hardness in Calexico in grains per gallon?
About 10.2 gpg. One grain per gallon equals 17.1 mg/L, so 174 mg/L divided by 17.1 gives 10.2.
What size water softener do I need in Calexico?
For 3 people using 75 gallons each per day, 10.2 gpg works out to about 2,290 grains a day. A 24,000-grain softener covers that with a regeneration about every 10 days.
Has the Calexico water system had EPA violations?
EPA records show 2 health-based violations for Calexico, City of since 2016, involving Lead and Copper Rule, Total trihalomethanes (TTHM). There were also 1 monitoring or reporting violation, which are about late or missing tests and notices.
Nearby cities
- Heber53 mg/LSoft
- El Centro150 mg/LHard
- Imperial94 mg/LModerately hard
- Brawley150 mg/LHard
- Mecca113 mg/LModerately hard
- Alpine209 mg/LVery hard
- San Diego Country Estates85 mg/LModerately hard
- Coachella99 mg/LModerately hard
- La Quinta113 mg/LModerately hard
- Jamul289 mg/LVery hard
Hardness data: TapWaterData US Water Hardness (utility report, March 2, 2023), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.