How hard is the water in Red Oak, TX?

Tap water hardness
86mg/L
5.0gpg
Moderately hardReports range 44–86

Reported by Rockett SUD · August 2025

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

Red Oak water measures 86 mg/L (5.0 gpg) of hardness, moderately hard by USGS standards. The number comes from Rockett SUD, dated August 2025. Reports for this system disagree, with values from 44 to 86 mg/L.

Red Oak on the hardness scale, with nearby cities
060120180240300360+TX typical 112Glenn Heights: 7 mg/LGlenn Heights 7Cedar Hill: 16 mg/LCedar Hill 16Midlothian: 41 mg/LMidlothian 41Waxahachie: 70 mg/LWaxahachie 70Ennis: 86 mg/LEnnis 86Lancaster: 96 mg/LLancaster 96DeSoto: 126 mg/LDeSoto 126Duncanville: 164 mg/LDuncanville 164Seagoville: 164 mg/LSeagoville 164Balch Springs: 164 mg/LBalch Springs 164Red Oak 86mg/L as calcium carbonate060120180240300360+TX 112Glenn Heights: 7 mg/LGlenn Heig. 7Cedar Hill: 16 mg/LCedar Hill 16Waxahachie: 70 mg/LWaxahachie 70Lancaster: 96 mg/LLancaster 96DeSoto: 126 mg/LDeSoto 126Duncanville: 164 mg/LDuncanville 16486 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

At 86 mg/L, Red Oak is 26 mg/L below the typical Texas figure of 112. Of the 10 nearest cities we track, 4 have softer water and 5 have harder. The range nearby runs from 7 mg/L in Glenn Heights to 164 in Duncanville.

What 86 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 Red Oak

3 people × 75 gallons a day × 5.0 gpg = 1,125 grains a day. A 24,000-grain unit regenerates about every 21 days.

Size it for your household

EPA record for Red Oak's water system

Rockett SUD · PWSID TX0700033

No health-based violations since 2016

Serves about 46,614 people from surface water.

Health-based
0
Monitoring or reporting
7
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 Red Oak water hard?

Somewhat. It measures about 86 mg/L (5.0 grains per gallon), which the USGS classes as moderately hard.

What is the water hardness in Red Oak in grains per gallon?

About 5.0 gpg. One grain per gallon equals 17.1 mg/L, so 86 mg/L divided by 17.1 gives 5.0.

What size water softener do I need in Red Oak?

For 3 people using 75 gallons each per day, 5.0 gpg works out to about 1,125 grains a day. A 24,000-grain softener covers that with a regeneration about every 21 days.

Has the Red Oak water system had EPA violations?

EPA records show no health-based violations for Rockett SUD since 2016. There were also 7 monitoring or reporting violations, which are about late or missing tests and notices.

Nearby cities

All 342 cities in Texas

Hardness data: TapWaterData US Water Hardness (utility report, August 26, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.