Marietta, GA water hardness

Tap water hardness
40mg/L
2.3gpg
Soft

Reported by Cobb County · September 2025

GA typical
28 mg/L
EPA health violations since 2016
0
Data
Utility report

Marietta water measures 40 mg/L (2.3 gpg) of hardness, soft by USGS standards. The number comes from Cobb County, dated September 2025.

Marietta on the hardness scale, with nearby cities
060120180240300360+GA typical 28Atlanta: 24 mg/LAtlanta 24Woodstock: 26 mg/LWoodstock 26Sandy Springs: 28 mg/LSandy Springs 28Fair Oaks: 40 mg/LFair Oaks 40Smyrna: 40 mg/LSmyrna 40Kennesaw: 40 mg/LKennesaw 40Vinings: 40 mg/LVinings 40Mableton: 40 mg/LMableton 40Acworth: 40 mg/LAcworth 40Austell: 40 mg/LAustell 40Marietta 40mg/L as calcium carbonate060120180240300360+GA 28Sandy Springs: 28 mg/LSandy Spri. 28Fair Oaks: 40 mg/LFair Oaks 40Smyrna: 40 mg/LSmyrna 40Kennesaw: 40 mg/LKennesaw 40Vinings: 40 mg/LVinings 40Mableton: 40 mg/LMableton 4040 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 40 mg/L, Marietta is 12 mg/L above the typical Georgia figure of 28. None of the 10 nearest cities we track has harder water. The range nearby runs from 24 mg/L in Atlanta to 40 in Fair Oaks.

What 40 mg/L means at home

Soap and shampoo lather with very little product. Kettles and showerheads stay mostly free of white crust.

Some people notice that soap feels slow to rinse off in soft water. That slippery feel is normal and harmless.

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

Nothing, as far as hardness goes. At 40 mg/L a softener would have almost nothing to remove.

Carbon filter

If the water tastes of chlorine, a pitcher or faucet carbon filter takes care of that. It does not change hardness.

EPA record for Marietta's water system

Cobb County · PWSID GA0670003

No health-based violations since 2016

Serves about 695,000 people from surface water.

Health-based
0
Monitoring or reporting
0
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 Marietta water hard?

No. It measures about 40 mg/L (2.3 grains per gallon), which the USGS classes as soft.

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

About 2.3 gpg. One grain per gallon equals 17.1 mg/L, so 40 mg/L divided by 17.1 gives 2.3.

Has the Marietta water system had EPA violations?

EPA records show no health-based violations for Cobb County since 2016.

Nearby cities

All 85 cities in Georgia

Hardness data: TapWaterData US Water Hardness (utility report, September 25, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.