Lunch & Learn with Linda MacGregor
Lunch & Learn with Linda MacGregor
Event Recap By Addison Chapman, Special Events and Marketing Intern
The Lake Lanier Association (LLA) welcomed attendees to its March Lunch & Learn featuring Linda MacGregor, from the City of Gainesville Water Resources Department. Guests had the opportunity to gain a deeper understanding of the ongoing taste and odor challenges affecting Lake Lanier’s drinking water, the science behind these occurrences, the steps being taken to address them, and the chance to ask MacGregor questions about all of the above.
From rising costs to advanced treatment technologies, MacGregor provided an educational and transparent look into how local water systems are adapting to increasingly complex environmental conditions.
WHAT CAUSES TASTE AND ODOR ISSUES IN DRINKING WATER AND IS THE WATER SAFE TO DRINK?
Taste and odor issues in drinking water are primarily caused by naturally occurring compounds called geosmin and 2-methylisoborneol (MIB). These compounds are produced by algae in the water and can create a musty or earthy smell and taste.
While these changes can be noticeable to consumers of Lake Lanier’s water, MacGregor emphasized that the water remains completely safe to drink and continues to meet or exceed all regulatory standards. In fact, humans can detect these compounds at extremely low levels; around 10 parts per trillion. This makes even minor changes more noticeable.
How Do Lake Lanier’s Taste and Odor Events Change Over The Years?
MacGregor discussed previous taste and odor events, including a noteworthy occurrence in 2017–2018 when MIB levels reached approximately 50 parts per trillion. At the time, Gainesville’s Riverside Water Treatment Plant responded by using powdered activated carbon (PAC), costing approximately $5.4 million.
In comparison, the current 2025–2026 event has presented even greater challenges. MIB levels have exceeded 1,000 parts per trillion, a significant increase. As a result, operational costs have risen, with PAC expenses increasing from a budgeted $400,000 to nearly $2 million.
WHAT CHALLENGES DO WATER SYSTEMS FACE TODAY?
Gainesville Water Resources is navigating several ongoing challenges, including aging infrastructure, increasing demand, regulatory requirements, and environmental factors such as drought. These issues, combined with more intense algae, make managing water quality more complex and costly.
In an effort to respond to the ongoing issues, the department has increased water sampling, adjusted treatment operations, and coordinated weekly efforts to monitor conditions and maintain water quality.
WHAT NEW TECHNOLOGIES ARE BEING EXPLORED?
Looking ahead, MacGregor highlighted advanced treatment options such as ozone and hydrogen peroxide systems. However, these solutions require significant investments. Over $50 million, and can take up to five years to design, permit, and construct.
Today, Gainesville is piloting an innovative ultrasonic technology system. Floating units placed near the water intake emit sound waves that disrupt algae growth by preventing them from rising to the surface. This process reduces the release of taste and odor compounds and allows for continuous monitoring of water conditions. 
HOW DOES THIS IMPACT THE COMMUNITY?
Although these challenges primarily affect taste and odor, they also have broader implications for operations, infrastructure, and long term water management. MacGregor emphasized the importance of continued investment and innovation to ensure safe, high quality drinking water for the growing community.
LOOKING AHEAD
The ultrasonic pilot program is ongoing, and the City of Gainesville plans to share updates as results become available. These updates will be available on the City of Gainesville’s Water Resources website linked below.
ADDITIONAL RESOURCES
Interested in learning more about the nutrient work that EPD has done on Lake Lanier? The 2017 Nutrient TMDL can be found at THIS LINK – It is the 5th report in the left hand column.
Learn more about the City of Gainesville Water Resources Department
GET INVOLVED
Events like the LLA Lunch & Learn provide a valuable opportunity for the community to stay informed and engaged with the issues impacting Lake Lanier and the surrounding community.
Click here to learn more about the LLA and becoming a member!
