Hard water in Selma, CA
County estimate from 366 water samples in Fresno County · July 2026
- CA typical
- 121 mg/L
- Softener for 3 people
- 24k grain
- Data
- County estimate
Water samples from around Selma put hardness at about 202 mg/L (11.8 gpg), which would be very hard on the USGS scale. Treat this as a rough guide: it is the median of 366 samples taken across Fresno County, mostly wells and streams, not a test of Selma's treated tap water.
Selma sits 81 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 10 mg/L in Mayfair to 202 in Reedley.
What 202 mg/L means at home
Scale forms fast here. Kettles and coffee makers need regular descaling, and showerheads clog unless you clean them.
Tank water heaters collect mineral sediment that insulates the water from the burner, so flushing the tank matters more than usual.
Dishes and glass shower doors spot easily. Soap scum and a dull film on hair or laundry are common complaints.
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 202 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 × 11.8 gpg = 2,657 grains a day. A 24,000-grain unit regenerates about every 9 days.
EPA record for Selma's water system
We could not match Selma to a community water system in EPA's records. Your water bill or the yearly Consumer Confidence Report names the system and its ID.
Questions
Is Selma water hard?
Yes. It measures about 202 mg/L (11.8 grains per gallon), which the USGS classes as very hard.
What is the water hardness in Selma in grains per gallon?
About 11.8 gpg. One grain per gallon equals 17.1 mg/L, so 202 mg/L divided by 17.1 gives 11.8.
What size water softener do I need in Selma?
For 3 people using 75 gallons each per day, 11.8 gpg works out to about 2,657 grains a day. A 24,000-grain softener covers that with a regeneration about every 9 days.
Nearby cities
- Kingsburg91 mg/LModerately hard
- Reedley202 mg/LVery hard
- Sanger202 mg/LVery hard
- Sunnyside167 mg/LHard
- Dinuba92 mg/LModerately hard
- Mayfair10 mg/LSoft
- Hanford11 mg/LSoft
- Orosi170 mg/LHard
- Clovis59 mg/LSoft
- Lemoore26 mg/LSoft
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.