For the first time in Lake Lanier’s history, blue-green algae blooms were spotted on its surface in 2020. Since then, the algae has been affecting more than 5 million people who get their drinking water from the lake. To combat this issue, the City of Gainesville has invested in three ultrasonic buoys.

According to the Lake Lanier Association, blue-green algae produces 2-methylisoborneol, or MIB, a compound that causes a “harmless yet disagreeable” taste and odor in drinking water. Linda MacGregor, the director of Gainesville Water Resources, says her department reported unusually high levels of a MIB in the water in 2025.

“The human threshold for noticing MIB is generally accepted as 10 parts per liter…and we had levels around 1,000,” said MacGregor, adding that experts described these levels as “rare” and “unseen.” She says that of the over 60,000 customers her department serves, more than 100 have called to express concerns about the quality of their drinking water.

“The water is perfectly safe to drink, even though it has this musty and earthy taste and odor,” says MacGregor. Regardless, city officials are working on a solution.

To reduce algae levels in Lake Lanier, the City of Gainesville has rented three ultrasonic buoys from LG Sonic, which it deployed in January.

These devices emit sound waves that interrupt the buoyancy of the algae, causing it to sink to the lake’s floor, says MacGregor. There, it can no longer photosynthesize, so it dies, preventing future algal blooms.

Although the effectiveness of the treatment won’t be clear until the lake turns over again next fall or spring, MacGregor says algae levels had already dropped by February.