How hard is the water in Franklin, TN?

Tap water hardness
98mg/L
5.8gpg
Moderately hard

Reported by Franklin Water Dept · September 2025

TN typical
89 mg/L
EPA health violations since 2016
7
Softener for 3 people
24k grain
Data
Utility report

Franklin water measures 98 mg/L (5.8 gpg) of hardness, moderately hard by USGS standards. The number comes from Franklin Water Dept, dated September 2025.

Franklin on the hardness scale, with nearby cities
060120180240300360+TN typical 89Nolensville: 62 mg/LNolensville 62Brentwood: 89 mg/LBrentwood 89Nashville: 89 mg/LNashville 89Ashland City: 89 mg/LAshland City 89Green Hill: 89 mg/LGreen Hill 89Murfreesboro: 101 mg/LMurfreesboro 101Columbia: 121 mg/LColumbia 121Spring Hill: 138 mg/LSpring Hill 138La Vergne: 200 mg/LLa Vergne 200Smyrna: 200 mg/LSmyrna 200Franklin 98mg/L as calcium carbonate060120180240300360+TN 89Nolensville: 62 mg/LNolensville 62Brentwood: 89 mg/LBrentwood 89Nashville: 89 mg/LNashville 89Spring Hill: 138 mg/LSpring Hill 138La Vergne: 200 mg/LLa Vergne 200Smyrna: 200 mg/LSmyrna 20098 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 98 mg/L, Franklin is close to the typical Tennessee figure of 89 mg/L. Of the 10 nearest cities we track, 5 have softer water and 5 have harder. The range nearby runs from 62 mg/L in Nolensville to 200 in La Vergne.

What 98 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 Franklin

3 people × 75 gallons a day × 5.8 gpg = 1,294 grains a day. A 24,000-grain unit regenerates about every 18 days.

Size it for your household

EPA record for Franklin's water system

Franklin Water Dept · PWSID TN0000246

7 health-based violations since 2016

Serves about 77,222 people from surface water.

Health-based
7
Monitoring or reporting
8
Open now
1
20162017201820192020202120222023202420252026Total trihalomethanes (TTHM)'16'18'20'22'24'26Total trihalomethanes (TTHM)
Each dot is one health-based violation, placed at the start of its compliance period.
Contaminant or ruleViolationsPeriodStatus
Total trihalomethanes (TTHM)a disinfection byproduct72019–2023Resolved

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 Franklin water hard?

Somewhat. It measures about 98 mg/L (5.8 grains per gallon), which the USGS classes as moderately hard.

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

About 5.8 gpg. One grain per gallon equals 17.1 mg/L, so 98 mg/L divided by 17.1 gives 5.8.

What size water softener do I need in Franklin?

For 3 people using 75 gallons each per day, 5.8 gpg works out to about 1,294 grains a day. A 24,000-grain softener covers that with a regeneration about every 18 days.

Has the Franklin water system had EPA violations?

EPA records show 7 health-based violations for Franklin Water Dept since 2016, involving Total trihalomethanes (TTHM). There were also 8 monitoring or reporting violations, which are about late or missing tests and notices.

Nearby cities

All 44 cities in Tennessee

Hardness data: TapWaterData US Water Hardness (utility report, September 10, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.