How hard is the water in Lewisville, TX?

Tap water hardness
90mg/L
5.2gpg
Moderately hardReports range 90–113

Reported by City of Lewisville · September 2025

TX typical
112 mg/L
EPA health violations since 2016
0
Softener for 3 people
24k grain
Data
Utility report

The water in Lewisville carries roughly 90 mg/L of dissolved calcium and magnesium, or 5.2 grains per gallon. That is moderately hard water. The number comes from City of Lewisville, dated September 2025. Reports for this system disagree, with values from 90 to 113 mg/L.

Lewisville on the hardness scale, with nearby cities
060120180240300360+TX typical 112Lantana: 6 mg/LLantana 6The Colony: 11 mg/LThe Colony 11Highland Village: 26 mg/LHighland Village 26Grapevine: 53 mg/LGrapevine 53Oak Point: 77 mg/LOak Point 77Flower Mound: 91 mg/LFlower Mound 91Hickory Creek: 93 mg/LHickory Creek 93Lake Dallas: 95 mg/LLake Dallas 95Carrollton: 136 mg/LCarrollton 136Coppell: 143 mg/LCoppell 143Lewisville 90mg/L as calcium carbonate060120180240300360+TX 112The Colony: 11 mg/LThe Colony 11Highland Village: 26 mg/LHighland V. 26Hickory Creek: 93 mg/LHickory Cr. 93Lake Dallas: 95 mg/LLake Dallas 95Carrollton: 136 mg/LCarrollton 136Coppell: 143 mg/LCoppell 14390 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Lewisville sits 22 mg/L below the typical Texas figure of 112. Of the 10 nearest cities we track, 5 have softer water and 5 have harder. The range nearby runs from 6 mg/L in Lantana to 143 in Coppell.

What 90 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 Lewisville

3 people × 75 gallons a day × 5.2 gpg = 1,179 grains a day. A 24,000-grain unit regenerates about every 20 days.

Size it for your household

EPA record for Lewisville's water system

City of Lewisville · PWSID TX0610004

No health-based violations since 2016

Serves about 140,880 people from surface water.

Health-based
0
Monitoring or reporting
1
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 Lewisville water hard?

Somewhat. It measures about 90 mg/L (5.2 grains per gallon), which the USGS classes as moderately hard.

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

About 5.2 gpg. One grain per gallon equals 17.1 mg/L, so 90 mg/L divided by 17.1 gives 5.2.

What size water softener do I need in Lewisville?

For 3 people using 75 gallons each per day, 5.2 gpg works out to about 1,179 grains a day. A 24,000-grain softener covers that with a regeneration about every 20 days.

Has the Lewisville water system had EPA violations?

EPA records show no health-based violations for City of Lewisville since 2016. 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, September 15, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.