How hard is the water in Tullahoma, TN?

Tap water hardness
81mg/L
4.7gpg
Moderately hardCounty estimate

County estimate from 149 water samples in Coffee County · July 2026

TN typical
89 mg/L
EPA health violations since 2016
0
Softener for 3 people
24k grain
Data
County estimate

Water samples from around Tullahoma put hardness at about 81 mg/L (4.7 gpg), which would be moderately hard on the USGS scale. Treat this as a rough guide: it is the median of 149 samples taken across Coffee County, mostly wells and streams, not a test of Tullahoma's treated tap water. One more reason for caution: EPA lists Tullahoma's water system as using surface water, which is often softer than the wells behind the county figure.

Tullahoma on the hardness scale, with nearby cities
060120180240300360+TN typical 89Nolensville: 62 mg/LNolensville 62Signal Mountain: 69 mg/LSignal Mountain 69Brentwood: 89 mg/LBrentwood 89Franklin: 98 mg/LFranklin 98Murfreesboro: 101 mg/LMurfreesboro 101Columbia: 121 mg/LColumbia 121Shelbyville: 130 mg/LShelbyville 130Spring Hill: 138 mg/LSpring Hill 138Smyrna: 200 mg/LSmyrna 200La Vergne: 200 mg/LLa Vergne 200Tullahoma 81mg/L as calcium carbonate060120180240300360+TN 89Nolensville: 62 mg/LNolensville 62Murfreesboro: 101 mg/LMurfreesbo. 101Shelbyville: 130 mg/LShelbyville 130Spring Hill: 138 mg/LSpring Hill 138Smyrna: 200 mg/LSmyrna 200La Vergne: 200 mg/LLa Vergne 20081 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 81 mg/L, Tullahoma is close to the typical Tennessee figure of 89 mg/L. Of the 10 nearest cities we track, 2 have softer water and 8 have harder. The range nearby runs from 62 mg/L in Nolensville to 200 in Smyrna.

What 81 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 Tullahoma

3 people × 75 gallons a day × 4.7 gpg = 1,064 grains a day. A 24,000-grain unit regenerates about every 22 days.

Size it for your household

EPA record for Tullahoma's water system

Tullahoma Utilities Authority · PWSID TN0000715

No health-based violations since 2016

Serves about 30,958 people from surface water.

Health-based
0
Monitoring or reporting
1
Open now
1

EPA lists this system as serving Tullahoma.

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 Tullahoma water hard?

Somewhat. It measures about 81 mg/L (4.7 grains per gallon), which the USGS classes as moderately hard.

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

About 4.7 gpg. One grain per gallon equals 17.1 mg/L, so 81 mg/L divided by 17.1 gives 4.7.

What size water softener do I need in Tullahoma?

For 3 people using 75 gallons each per day, 4.7 gpg works out to about 1,064 grains a day. A 24,000-grain softener covers that with a regeneration about every 22 days.

Has the Tullahoma water system had EPA violations?

EPA records show no health-based violations for Tullahoma Utilities Authority since 2016. There were also 1 monitoring or reporting violation, which are about late or missing tests and notices.

Nearby cities

All 44 cities in Tennessee

Hardness data: TapWaterData US Water Hardness (county estimate, July 4, 2026), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.