In recent months, Forsyth County residents have reported strange smells in their water, and county officials are reiterating that the smell is being caused by a natural source and the water is safe to drink.
According to information posted on the Forsyth County’s website, the unusual taste and smell being are caused by higher-than-normal levels of Methylisoborneol (MIB) and Geosmin in raw water taken in from Lake Lanier.
“Both Geosmin and MIB are naturally occurring compounds found in surface waters, such as Lake Lanier,” the post said. “They are organic molecules produced by algae. This year the levels in Lake Lanier started to rise in early August but appear to be dropping in early October.”
Bright sun, warm temperatures and nutrients in the water make late summer into early fall an ideal time for the algae to grow, and the compounds are released when the organisms die.
While the compounds are not harmful, they do impact the water’s taste and odor, which the post described as “similar to that found in overturned rich soils, and is present in some foods such as beets, spinach and mushrooms.”
Per the information, the human nose is extremely sensitive to Geosmin and heating the water can make the smell worse.
“If you poured a teaspoon of Geosmin into the equivalent of 200 Olympic-sized swimming pools, some people would still be able to smell it,” the post said. “Heating the water can increase the volatility of these compounds, which explains why the smell is more easily detected when you are in the shower or using heated water.”
To lower the levels of the compounds, the county’s water and sewer department is using a powder activated carbon (PAC) system at the drinking water treatment facility, and the water is tested on a regular basis, with the Environmental Protection Division of the Georgia Department of Natural Resources and Forsyth County performing more than 1,300 tests each year.
There are plans to add Ozone disinfection to the drinking water process, and that should be done within the next year.
While it is not clear how long the smell and taste will be present, the release said “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 again reach undetectable levels.”