How hard is the water in Houston, TX?

Tap water hardness
96mg/L
5.6gpg
Moderately hardReports range 96–119

Reported by City of Houston · October 2025

TX typical
112 mg/L
EPA health violations since 2016
1
Softener for 3 people
24k grain
Data
Utility report

The water in Houston carries roughly 96 mg/L of dissolved calcium and magnesium, or 5.6 grains per gallon. That is moderately hard water. The number comes from City of Houston, dated October 2025. Reports for this system disagree, with values from 96 to 119 mg/L.

Houston on the hardness scale, with nearby cities
060120180240300360+TX typical 112Jacinto City: 33 mg/LJacinto City 33Channelview: 42 mg/LChannelview 42Cloverleaf: 48 mg/LCloverleaf 48Humble: 52 mg/LHumble 52Bellaire: 54 mg/LBellaire 54Galena Park: 57 mg/LGalena Park 57Stafford: 57 mg/LStafford 57South Houston: 60 mg/LSouth Houston 60Pearland: 79 mg/LPearland 79West University Place: 88 mg/LWest University Place 88Houston 96mg/L as calcium carbonate060120180240300360+TX 112Jacinto City: 33 mg/LJacinto Ci. 33Cloverleaf: 48 mg/LCloverleaf 48Bellaire: 54 mg/LBellaire 54Galena Park: 57 mg/LGalena Park 57South Houston: 60 mg/LSouth Hous. 60West University Place: 88 mg/LWest Unive. 8896 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Houston sits 16 mg/L below the typical Texas figure of 112. None of the 10 nearest cities we track has harder water. The range nearby runs from 33 mg/L in Jacinto City to 88 in West University Place.

What 96 mg/L means at home

You may see faint white spots on glasses and shower doors after the water dries.

Scale builds up slowly. A kettle or coffee maker needs descaling now and then, maybe every few months.

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

Optional. Plenty of households at this level live with it and descale the kettle now and then.

Water softener

Worth a look if spots on glass bother you, or if your tankless water heater manual asks for softer water.

Carbon filter

Improves taste and removes chlorine. It leaves calcium and magnesium in place.

Softener size for Houston

3 people × 75 gallons a day × 5.6 gpg = 1,260 grains a day. A 24,000-grain unit regenerates about every 19 days.

Size it for your household

EPA record for Houston's water system

City of Houston · PWSID TX1010013

1 health-based violation since 2016

Serves about 2,970,543 people from surface water.

Health-based
1
Monitoring or reporting
1
Open now
0
20162017201820192020202120222023202420252026Surface Water Treatment Rule'16'18'20'22'24'26Surface Water Treatment Rule
Each dot is one health-based violation, placed at the start of its compliance period.
Contaminant or ruleViolationsPeriodStatus
Surface Water Treatment Rulefiltration and disinfection12025Resolved

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 Houston water hard?

Somewhat. It measures about 96 mg/L (5.6 grains per gallon), which the USGS classes as moderately hard.

What is the water hardness in Houston in grains per gallon?

About 5.6 gpg. One grain per gallon equals 17.1 mg/L, so 96 mg/L divided by 17.1 gives 5.6.

What size water softener do I need in Houston?

For 3 people using 75 gallons each per day, 5.6 gpg works out to about 1,260 grains a day. A 24,000-grain softener covers that with a regeneration about every 19 days.

Has the Houston water system had EPA violations?

EPA records show 1 health-based violation for City of Houston since 2016, involving Surface Water Treatment Rule. There were also 1 monitoring or reporting violation, which are about late or missing tests and notices.

Nearby cities

All 342 cities in Texas

Hardness data: TapWaterData US Water Hardness (utility report, October 14, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.