Forsyth County Upgrades Water Plant After Fall Odor Complaints

Months of earthy, musty tap water traced to a Lake Lanier algal bloom pushed Forsyth County commissioners to approve upgrades at the Antioch Water Treatment Plant, the 28-million-gallon-per-day facility on Antioch Road in north Forsyth that serves as the county's primary source of treated drinking water.

The source of last fall's complaints was a pair of naturally occurring chemical compounds, geosmin and 2-methylisoborneol, known as MIB, which algae in Lake Lanier produce when warm conditions accelerate bloom growth. Both compounds are harmless at the concentrations present in treated tap water, but human senses detect geosmin at as little as five parts per trillion, making even trace amounts in a glass of water unmistakably noticeable. Boiling water does not help; geosmin actually intensifies under heat, meaning tea and coffee brewed during the bloom tasted worse than cold tap water.

The county has previously added an ozone treatment stage to the Antioch plant specifically to combat seasonal taste and odor events, but the scale and duration of last fall's bloom exposed the limits of existing capacity. The commissioners' vote to expand and upgrade the plant represents a direct institutional acknowledgment that the current system was overwhelmed.

Residents with water quality concerns can contact the Forsyth County Department of Water and Sewer through the county's main government portal at forsythco.com or by calling the department directly. The county publishes an annual water quality report online that includes testing data for contaminants, byproducts, and compounds such as geosmin and MIB, giving residents a consistent benchmark for what is in their tap water each year.

Water and sewer services in Forsyth County are funded through user rates rather than property taxes, meaning infrastructure upgrades of this kind are typically reflected in rate structures over time rather than in general fund levies. The county has in recent years also secured significant state funding for water infrastructure, including a $32.6 million grant announced for future water and sewer projects, which offsets the capital costs residents would otherwise absorb directly.

Lake Lanier algal blooms are a recurring seasonal variable that no treatment upgrade can fully eliminate at the source, but expanded ozone and filtration capacity at Antioch is designed to ensure that when the next bloom arrives, the plant can process it without the months-long odor event that residents endured last fall.