Hard water in Fair Oaks Ranch, TX
Reported by San Antonio Water System · October 2025
- TX typical
- 112 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 24k grain
- Data
- Utility report
The water in Fair Oaks Ranch carries roughly 180 mg/L of dissolved calcium and magnesium, or 10.5 grains per gallon. That is hard water. The number comes from San Antonio Water System, dated October 2025. Reports for this system disagree, with values from 180 to 214 mg/L.
At 180 mg/L, Fair Oaks Ranch is 68 mg/L above the typical Texas figure of 112. None of the 10 nearest cities we track has harder water. The range nearby runs from 157 mg/L in Bulverde to 180 in Scenic Oaks.
What 180 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 180 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 × 10.5 gpg = 2,365 grains a day. A 24,000-grain unit regenerates about every 10 days.
EPA record for Fair Oaks Ranch's water system
No health-based violations since 2016
Serves about 9,768 people from surface water.
- Health-based
- 0
- Monitoring or reporting
- 1
- Open now
- 0
EPA lists Fair Oaks Ranch Utilities as the system serving Fair Oaks Ranch. The hardness figure above comes from a different system's report, which TapWaterData uses for Fair Oaks Ranch.
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 Fair Oaks Ranch water hard?
Yes. It measures about 180 mg/L (10.5 grains per gallon), which the USGS classes as hard.
What is the water hardness in Fair Oaks Ranch in grains per gallon?
About 10.5 gpg. One grain per gallon equals 17.1 mg/L, so 180 mg/L divided by 17.1 gives 10.5.
What size water softener do I need in Fair Oaks Ranch?
For 3 people using 75 gallons each per day, 10.5 gpg works out to about 2,365 grains a day. A 24,000-grain softener covers that with a regeneration about every 10 days.
Has the Fair Oaks Ranch water system had EPA violations?
EPA records show no health-based violations for Fair Oaks Ranch Utilities since 2016. There were also 1 monitoring or reporting violation, which are about late or missing tests and notices.
Nearby cities
- Scenic Oaks180 mg/LVery hard
- Timberwood Park180 mg/LHard
- Helotes180 mg/LHard
- Bulverde157 mg/LHard
- Leon Valley180 mg/LHard
- San Antonio179 mg/LHard
- Alamo Heights180 mg/LHard
- Terrell Hills180 mg/LHard
- Windcrest180 mg/LHard
- Live Oak180 mg/LHard
Hardness data: TapWaterData US Water Hardness (utility report, October 7, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.