Mableton Water Hardness & Quality Report (2026)

Mableton, Georgia, in Cobb County — a major southwest Cobb County community that was incorporated as a city in 2023 (Mableton was one of the largest unincorporated communities in Georgia before incorporation — a major southwest Cobb County residential and commercial center), a diverse Cobb County community with a significant African-American, Latino-American, and South Asian-American population, adjacent to Smyrna and South Cobb in the southwest Atlanta metro, and part of the rapidly urbanizing southwest Cobb County corridor — draws its municipal water supply from the Chattahoochee River and Lake Allatoona via the Cobb County Water System. Water hardness in Mableton measures 131.5 mg/L — classified as moderately hard.

Mableton's moderate hardness reflects the northwest Georgia Piedmont Chattahoochee River watershed's calcareous-moderate crystalline geology. The Chattahoochee River at Cobb County–Mableton drains: the Georgia Piedmont Belt (Precambrian–Paleozoic calcareous-moderate Henderson Gneiss and Brevard Zone mylonite — the west Georgia Piedmont); the Cobb County Inner Piedmont (calcareous-moderate amphibolite and metasediment). Cobb County Water System treatment produces the moderate 131.5 mg/L.

At 131.5 mg/L, Mableton residents encounter moderate scale accumulation. Monthly cleaning with citric acid solution is recommended. Cobb County Water System consistently delivers water meeting all Georgia EPD and EPA Safe Drinking Water Act requirements.