Understanding Recent Water Conditions

November 17, 2025

MARIETTA, GA - Water customers in Marietta may have noticed a different taste and smell from their tap water over the last several days. Our regional water sources, including the Chattahoochee River and Allatoona Lake, are currently experiencing high levels of Methyl-Isoborneol (MIB), a naturally occurring compound in water sources. MIB is not a health concern but can cause an earthy or musty taste or smell.

Increases in MIB typically occur in the fall of the year, with changes in the temperature and water level in the reservoirs. MIB is difficult to remove during water treatment and requires advanced treatment processes. Our regional water provider, the Cobb County-Marietta Water Authority, has increased these treatment methods to help offset the record MIB levels we are seeing this season. Because the metro area shares water sources, many utilities in the region are experiencing the same issue.

Our drinking water remains safe and is continuously monitored. While MIB does not pose a health concern, it can affect taste and odor. If you find your tap water is not as aesthetically pleasing during this time, try running it through a carbon filter (like many refrigerators have) or chilling the water.

For additional information or questions, call Marietta Water at 770-794-5230 or visit:

https://www.ccmwa.org/education/geosmin-and-methyl-isoborneol-mib