Water Quality Frequently Asked Questions
Update as of December 9, 2025
Overview
The City of Atlanta Department of Watershed Management (DWM) is aware that some residents are experiencing an unusual taste and odor in their water. Testing of the raw water from Lake Lanier into the Chattahoochee River has confirmed that levels of Methylisoborneol (MIB) and Geosmin are higher than have been seen in past years. While these naturally occurring compounds are not harmful, they do affect the aesthetics of the water, specifically taste and odor. This normally occurs during the changes of the seasons, specifically when water temperatures are warmer, and algae and bacteria are more active. As the weather conditions and the water quality in Lake Lanier change and the levels of these compounds in the raw water are reduced, these compounds will decrease until they reach undetectable levels. Also, issues related to taste and odor may arise from internal plumbing or household fixtures. In this case, the usage of carbon filters is recommended.
FAQs
What is Causing the Odd Taste and Smell of our Water?
The suspected cause is high levels of naturally occurring compounds, Methylisoborneol and Geosmin, found in surface water from the Chattahoochee River.
Is the Water Safe to Drink?
Yes, tests performed by our Water Quality staff confirm that our drinking water continues to be safe to drink. DWM is flushing mains in impacted areas and enhancing the water treatment processes in order to reduce the taste and odor issues.
The City’s drinking water continues to meet or exceed standards established by the U.S. Environmental Protection Agency (EPA) as required by the Federal Safe Drinking Water Act.
What We’re Doing to Address the Issue?
The City conducts more than 50,000 tests annually to screen for more than 150 potential contaminants in its drinking water.
The City is closely monitoring both Geosmin and MIB levels at our drinking water plants to ensure that water quality remains safe. Our monitoring efforts include:
- Proactive testing: Routinely and regularly testing for Geosmin and MIB.
- Treatment steps: When levels rise, increase treatment processes, such as adding Powdered Activated Carbon (PAC), which helps absorb and remove these compounds, significantly improving taste and odor.
For more information, review DWM’s water quality reports here: https://www.atlantawatershed.org/water-quality-reports/.
