Cobb County, Georgia: drinking water report. Cobb County lies northwest of Atlanta, home to about 770,000 residents.
Cobb County lies northwest of Atlanta, home to about 770,000 residents. Cobb County-Marietta Water Authority draws from the Chattahoochee River at Lake Allatoona and the Chattahoochee River downstream of Buford Dam. The county operates two water treatment plants with a combined capacity exceeding 130 million gallons per day. The Chattahoochee River is the primary water source for much of metro Atlanta, and demand from multiple counties creates competition for allocation during drought years.
Cobb County's water system has maintained solid compliance records. UCMR5 data shows low-level PFAS detections. Dobbins Air Reserve Base in Marietta is a documented PFAS source – the Department of Defense has confirmed AFFF use and groundwater contamination at the installation. According to the Georgia EPD's 2024 monitoring data, PFAS readings in the Cobb County system were below proposed federal MCLs, but monitoring wells near Dobbins show elevated levels.
The Chattahoochee River's water quality is generally good, though it receives treated wastewater effluent and stormwater from upstream communities. During the 2007-2008 drought, Lake Lanier dropped to historically low levels, and the tri-state water war between Georgia, Florida, and Alabama underscored how precarious the region's supply can be.
Cobb County's water meets federal standards, but proximity to Dobbins ARB makes PFAS monitoring worth tracking.
Check your water for current data in your area. An activated carbon filter addresses taste and provides some PFAS reduction. For fuller PFAS protection, reverse osmosis is more effective. Our water filter guide covers both. Pull your detailed report, and visit our Georgia page for statewide patterns.