Hard water in Sienna, TX
Reported by Sienna MUD 4 · June 2025
- TX typical
- 112 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 24k grain
- Data
- Utility report
Tap water in Sienna has about 170 mg/L of hardness, which is 9.9 grains per gallon. On the USGS scale that counts as hard. The number comes from Sienna MUD 4, dated June 2025.
At 170 mg/L, Sienna is 58 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 54 mg/L in Bellaire to 118 in Sugar Land.
What 170 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 170 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 × 9.9 gpg = 2,236 grains a day. A 24,000-grain unit regenerates about every 10 days.
EPA record for Sienna's water system
No health-based violations since 2016
Serves about 6,435 people from groundwater.
- Health-based
- 0
- Monitoring or reporting
- 1
- Open now
- 0
TapWaterData ties Sienna to this system. EPA's service-area records do not name Sienna, 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 Sienna water hard?
Yes. It measures about 170 mg/L (9.9 grains per gallon), which the USGS classes as hard.
What is the water hardness in Sienna in grains per gallon?
About 9.9 gpg. One grain per gallon equals 17.1 mg/L, so 170 mg/L divided by 17.1 gives 9.9.
What size water softener do I need in Sienna?
For 3 people using 75 gallons each per day, 9.9 gpg works out to about 2,236 grains a day. A 24,000-grain softener covers that with a regeneration about every 10 days.
Has the Sienna water system had EPA violations?
EPA records show no health-based violations for Sienna MUD 4 since 2016. There were also 1 monitoring or reporting violation, which are about late or missing tests and notices.
Nearby cities
- Missouri City67 mg/LModerately hard
- Stafford57 mg/LSoft
- Sugar Land118 mg/LModerately hard
- Pearland79 mg/LModerately hard
- Bellaire54 mg/LSoft
- West University Place88 mg/LModerately hard
- Richmond62 mg/LModerately hard
- Friendswood69 mg/LModerately hard
- Rosenberg108 mg/LModerately hard
- South Houston60 mg/LModerately hard
Hardness data: TapWaterData US Water Hardness (utility report, June 22, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.