How hard is the water in Princeton, TX?

Tap water hardness
116mg/L
6.8gpg
Moderately hard

Reported by City of Princeton · October 2025

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

Tap water in Princeton has about 116 mg/L of hardness, which is 6.8 grains per gallon. On the USGS scale that counts as moderately hard. The number comes from City of Princeton, dated October 2025.

Princeton on the hardness scale, with nearby cities
060120180240300360+TX typical 112Anna: 62 mg/LAnna 62Fairview: 90 mg/LFairview 90Murphy: 108 mg/LMurphy 108Allen: 109 mg/LAllen 109Lucas: 110 mg/LLucas 110Melissa: 111 mg/LMelissa 111Wylie: 126 mg/LWylie 126Lavon: 126 mg/LLavon 126McKinney: 132 mg/LMcKinney 132Farmersville: 134 mg/LFarmersville 134Princeton 116mg/L as calcium carbonate060120180240300360+TX 112Fairview: 90 mg/LFairview 90Lucas: 110 mg/LLucas 110Melissa: 111 mg/LMelissa 111Wylie: 126 mg/LWylie 126McKinney: 132 mg/LMcKinney 132Farmersville: 134 mg/LFarmersvil. 134116 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Princeton sits close to the typical Texas figure of 112 mg/L. Of the 10 nearest cities we track, 6 have softer water and 4 have harder. The range nearby runs from 62 mg/L in Anna to 134 in Farmersville.

What 116 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 Princeton

3 people × 75 gallons a day × 6.8 gpg = 1,526 grains a day. A 24,000-grain unit regenerates about every 15 days.

Size it for your household

EPA record for Princeton's water system

City of Princeton · PWSID TX0430008

No health-based violations since 2016

Serves about 37,019 people from surface water.

Health-based
0
Monitoring or reporting
4
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 Princeton water hard?

Somewhat. It measures about 116 mg/L (6.8 grains per gallon), which the USGS classes as moderately hard.

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

About 6.8 gpg. One grain per gallon equals 17.1 mg/L, so 116 mg/L divided by 17.1 gives 6.8.

What size water softener do I need in Princeton?

For 3 people using 75 gallons each per day, 6.8 gpg works out to about 1,526 grains a day. A 24,000-grain softener covers that with a regeneration about every 15 days.

Has the Princeton water system had EPA violations?

EPA records show no health-based violations for City of Princeton since 2016. There were also 4 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, October 10, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.