The first day of fall is almost here, and cooler temperatures are finally on the horizon for the Southeast. In Atlanta, that means Falcons football is back on television, parks are starting to see the fall colors and Atlanta's water is about to get musty.
City locals now know that the fall season brings a peculiar smell and taste to Atlanta's water, but the water itself is completely safe to drink, according to watershed officials.
Here's what to know about the seasonal stink.
Where does Atlanta's water come from?
The Metropolitan North Georgia Water Planning District includes 15 counties in North Georgia, in which the entire Atlanta metro area lies and some of the surrounding suburban areas.
The majority of the water for the entire district comes from the Chattahoochee River Basin.
A total of 71% of all the water in the Atlanta metro is pulled directly from the Chattahoochee River and Lake Lanier, a reservoir northeast of the city. The rest of the water comes from the Etowah, Flint and Ocmulgee rivers.
Other than Lake Lanier, Lake Allatoona is also a federal reservoir, and the reservoirs are used not only for direct water supply but for flood control, hydroelectric power, recreation and fishing.
Rainfall helps the reservoirs stay full, and since May the city of Atlanta has had above average rainfall for the summer following months of drought. In July, for example, the city averages 4.75 inches of rain, but it experienced 6.14 inches this year.
Why does Atlanta's water smell?
When water temperatures are warmer in the Chattahoochee River, and Lake Lanier as the river supplies the reservoir, there is an increased growth in two naturally occurring compounds.
Methylisoborneol (MIB) and geosmin are both natural compounds, and are created from algae, fungi and soil bacteria. They are completely harmless to consume, but have an earthy, musty smell that can also make water have the same smell.
The smell, and sometimes taste, isn't filtered out through standard water treatment or household filters.
Why is the smell worse in the fall?
Because the smell is created by algae, fungi and soil bacteria, there is typically more of the compounds following periods of extended warmth, according to the City of Atlanta Department of Watershed Management.
"This normally occurs during the changes of the seasons, specifically when water temperatures are warmer, and algae and bacteria are more active," officials say. "As the weather conditions and the water quality in Lake Lanier change, the levels of these compounds will decrease until undetectable."
The city of Atlanta, and the rest of North Georgia, has had an extended period of warm weather this year, pushing further and further into the typical fall season, meaning the smell may last a little longer this year than it has in the past.
Is Atlanta water still safe to drink?
Methylisoborneol (MIB) and geosmin are both completely harmless to consume and will not impact your health.
Water officials add additional treatment protocols to the city water during these periods to try and address the off-putting smell and taste. But, the water can also taste better when it is chilled in the fridge, filtered again through a pitcher or by adding a slice of lemon or another fruit.
Irene Wright is the Atlanta Connect reporter with USA Today’s Deep South Connect team. Find her on X @IreneEWright or email her at ismith@usatodayco.com.
This article originally appeared on USA TODAY: Why does my water smell like that? Don't worry, Atlanta's water is safe
