Marietta Water Hardness & Quality Report (2026)

The City of Marietta Water Department serves approximately 30,000 customers in the City of Marietta and parts of Cobb County, Georgia. Water is primarily sourced from the Chattahoochee River and treated at the City of Atlanta's Hemphill Water Treatment Plant and R. D. Brown Water Treatment Plant under a wholesale agreement. Additional supply may come from Cobb County's resources or local wells, covering central Cobb County and the city core within the Atlanta metropolitan region. Treatment at partner plants employs coagulation, sedimentation, filtration, and chlorination, with fluoride added for dental health.

The supply originates in the Upper Chattahoochee River watershed, spanning the Blue Ridge and Piedmont physiographic provinces. Key geological features include metamorphic rocks such as gneiss and schist from the Precambrian Grenville orogeny, interspersed with Paleozoic sedimentary layers and some limestone and dolomite outcrops; no major karst aquifers dominate, with fractured bedrock aquifers contributing instead. These crystalline rocks weather slowly, releasing moderate calcium and magnesium into the water and producing a moderately mineralized character typical of the Appalachian Piedmont province.

As moderately hard water, Marietta's supply promotes moderate scale buildup in pipes, water heaters, dishwashers, and washing machines, reducing efficiency and lifespan over time. Soap lathering can be less effective, leading to higher detergent use; maintenance tips include regular flushing of water heaters, installing scale-inhibiting filters, and vinegar-based cleaning. A water softener is optional but recommended for households noticing spots on dishes or dry skin. pH typically ranges 7.5–7.8 and the utility complies with lead and copper rules through corrosion control; Annual Consumer Confidence Reports from Marietta and Cobb County confirm low levels of regulated substances with fluoride added for dental health.