Hard water in Plano, TX
Reported by City of Plano · September 2025
- TX typical
- 112 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 24k grain
- Data
- Utility report
Tap water in Plano has about 150 mg/L of hardness, which is 8.8 grains per gallon. On the USGS scale that counts as hard. The number comes from City of Plano, dated September 2025.
At 150 mg/L, Plano is 38 mg/L above the typical Texas figure of 112. Of the 10 nearest cities we track, 7 have softer water and 2 have harder. The range nearby runs from 11 mg/L in The Colony to 168 in Farmers Branch.
What 150 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 150 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 × 8.8 gpg = 1,973 grains a day. A 24,000-grain unit regenerates about every 12 days.
EPA record for Plano's water system
No health-based violations since 2016
Serves about 292,059 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 Plano water hard?
Yes. It measures about 150 mg/L (8.8 grains per gallon), which the USGS classes as hard.
What is the water hardness in Plano in grains per gallon?
About 8.8 gpg. One grain per gallon equals 17.1 mg/L, so 150 mg/L divided by 17.1 gives 8.8.
What size water softener do I need in Plano?
For 3 people using 75 gallons each per day, 8.8 gpg works out to about 1,973 grains a day. A 24,000-grain softener covers that with a regeneration about every 12 days.
Has the Plano water system had EPA violations?
EPA records show no health-based violations for City of Plano since 2016.
Nearby cities
- Allen109 mg/LModerately hard
- Richardson150 mg/LHard
- Frisco149 mg/LHard
- Murphy108 mg/LModerately hard
- The Colony11 mg/LSoft
- Carrollton136 mg/LHard
- Fairview90 mg/LModerately hard
- Lucas110 mg/LModerately hard
- Sachse164 mg/LHard
- Farmers Branch168 mg/LHard
Hardness data: TapWaterData US Water Hardness (utility report, September 15, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.