Chlorophyll, or algae, levels in Lake Lanier reached a 20-year high in 2019, according to Chattahoochee Riverkeeper.
On Tuesday, the water protection group announced the findings of monitoring data it collected on the lake last year. The result was that chlorophyll, which is an indicator of algae, reached its highest level seen in two decades of water monitoring.
“Our region’s prosperity depends on a healthy Lake Lanier,” Chattahoochee Riverkeeper Headwaters Director Dale Caldwell said. “The high algae levels that we saw in 2019 indicate that we need to do a better job of controlling the amount of nutrients flowing into the lake.”
Chattahoochee Riverkeeper officials said the chlorophyll levels on the lake increased by 3.72 ug/ L from 2018 to 2019. The increase had only averaged 0.17 ug/ L per year from 2000 to 2018, the group said.
The reason why the lake's chlorophyll levels are important is because they can affect the quality of water pulled from the lake to serve area residents, affecting its taste and smell. It can also lead to higher costs to communities to treat the water to get it to the point that it meets safe drinking standards.
Algae blooms occur if too many nutrients are flowing into the lake with Chattahoochee Riverkeeper saying pollution from industrial facilities, agricultural operations, sewage treatment plants and stormwater runoff can increase algae blooms.
The Georgia Environmental Protection Division began monitoring the lake in 2000 by taking water samples. In 2010, Chattahoochee Riverkeeper began doing its own testing, once a month from April to October, at 10 sites around the lake.
Riverkeeper officials said a federally-required clean-up plan began to be activated in recent years as chlorophyll levels exceeded the maximum level set by the state. The organization said the 2019 data was proof that implementation of the plan by local governments and utilities, among other lake stakeholders, needs to be expedited.
“This alarming spike in chlorophyll levels highlights the need for this cleanup plan,” Riverkeeper Jason Ulseth said. “We will be doing everything we can to make sure that those who manage the sources of the excess nutrients flowing into Lake Lanier are taking action to address this public health threat as quickly as possible.”