SML saved from harmful algal blooms this summer, but efforts to monitor still ongoing (2024)

MONETA — As summer comes to a close at Smith Mountain Lake, the algal blooms that plagued the waters last year have not returned, to the relief of many residents and businesses on the shore.

The Smith Mountain Lake Association last year launched an effort to figure out the reasons for the dip in water quality as well as to plot strategies to track any new algal blooms before they became a problem this year. Surprisingly, testing done this summer has found the lake is currently the cleanest it has been in years.

The association started its Dock Watch program late last year to monitor for harmful algal blooms. Volunteers from around the lake test water samples at 20 sites each week throughout the year.

Keri Green, chair of SMLA’s Lake Quality Council who oversees the Dock Watch program, said nothing unusual was found in sample taken this summer. Volunteers use microscopes purchased for the program to analyze samples at a lab in the SMLA office in Westlake.

Green said the lack of any major algal blooms was both a blessing and a curse. It allowed time for volunteers to learn how to use the equipment without dealing with major outbreaks, but it also turned last year’s algal blooms into a “cold case” with any traces seemingly disappeared into the lake’s depths.

The SMLA’s Water Quality Monitoring Program it coordinates with Ferrum College also has seen positive results when it comes to the lake’s overall health. Tom Hardy, SMLA’s water quality monitoring chair, said water samples taken this summer found the water was clearer than it has been in previous years with zero reports of dangerous levels E. coli found in any samples that would lead to a swim advisory.

“This has been, from a water quality standpoint, one of the best years,” Hardy said.

Hardy said the water quality at Smith Mountain Lake this year “significantly outperformed the average of the past 20 years” in measured categories of water clarity, chlorophyll-a concentration and phosphorus concentration.

It’s a far different story from last year where Smith Mountain Lake had a swim advisory in place for much of the summer due to multiple harmful algal blooms appearing in the Blackwater River arm of the lake. That harmful algae, usually blue-green in color, is made up of cyanobacteria that sometimes produces microcystin, a toxin that can cause skin rash and gastrointestinal illnesses, such as upset stomach, nausea, vomiting and diarrhea.

While both Hardy and Green said there are likely multiple factors that contributed to the cleaner water this year, they both pointed to the lack of any significant heavy rains as a key reason. Last year the lake was hit with several heavy rains in May with the algal blooms arriving soon after.

Green said the rain isn’t exactly the problem, its the runoff from the shoreline. That runoff introduces materials in the lake like phosphorus that feeds algae. It can also transport E.coli from animal waste from farms around the lake or tributaries or possibly even from leaking septic systems from homes near the shoreline.

“The rain isn’t the cause, its the transport mechanism,” Green said.

The Smith Mountain Lake Association hired watershed management and ecological restoration firm Princeton Hydro last year to study the tributaries into the Blackwater River arm of the lake. They were tasked with trying to identify possible causes for last year’s algal blooms.

Princeton Hydro is looking into sediment composition and its connection to the growth of harmful algal blooms as well as trying to develop predictive tools to help monitor for future blooms. Green said those results should be available later next month.

A second study funded by the state earlier this year is also set to begin in the coming months. Virginia’s finalized budget in March included $150,000 provided for the Virginia Department of Environmental Quality and Virginia Tech to work with SMLA to create the study.

Green said the study will look at land use around the lake and its tributaries as well as look at prior data from the water quality monitoring program and from DEQ to find possible causes for last year’s algal blooms. That study is expected to be completed by the end of June.

Efforts are also underway to obtain certification for Ferrum College that will allow the lab there to analyze water samples if any harmful algal blooms are found in the future. Samples were required by DEQ to be sent to Old Dominion University last summer to test since it was the only lab certified to do it, which delayed results by several weeks and possibly prolonged the amount of time Smith Mountain Lake was under a swim advisory last summer.

Green said DEQ has agreed to a pilot program next year for Ferrum College that could see it get certification. DEQ would allow scientists at the college to join them when collecting any samples of potentially harmful algal blooms at the lake for testing. Ferrum College would then provide its own testing separate from DEQ to assure they get the same results.

If things go well, Green said the Ferrum College lab could possibly obtain certification to test the samples as early as 2026. With testing conducted just a short distance away from the lake, results could be returned in hours or days instead of waiting weeks.