Latest Water Quality Results Show SML Remains Clean and Safe for Recreation
SMITH MOUNTAIN LAKE, VA – The third round of sampling this summer done by the Smith Mountain Lake Association Water Quality Monitoring program shows mixed results compared to the previous set of readings. Water clarity decreased modestly and chlorophyll-a and phosphorus levels significantly improved. These results are in line with SML 20-year averages and indicate that the lake remains clean and safe for recreation.
Water clarity reflects the volume of particles suspended in the water, primarily algae and sediment. The average water clarity across all sites sampled in the lake for the week ending June 20 measured 2.10 meters, a slight decrease compared to the previous week’s reading of 2.32 meters and the corresponding 20-year average of 2.28 meters. It is typical for water clarity to decline somewhat during the summer due to cumulative algae growth and increased boat traffic.
Chlorophyll-a is a measure of the volume of algae growing in the lake and is expressed in terms of parts per billion, or ppb. The average concentration of chlorophyll-a across all sites sampled for the week ending June 20 was 7.59 ppb, a significant improvement compared to the previous week’s result of 8.05 ppb, though still higher than the corresponding 20-year average of 6.99 ppb.
Phosphorus is a key nutrient for all living organisms. Too much phosphorus in the water can contribute to undesirable growth of algae. The average concentration of Phosphorus across all sites sampled for the week ending June 20 was 25.40 ppb, a significant improvement compared to the previous week’s result of 32.16 ppb, and slightly better than the corresponding 20-year average of 28.25 ppb.
These results are an average of all the sites monitored on the lake. Despite ongoing high temperatures and low water levels, Smith Mountain Lake Association (SMLA) Water Quality Monitoring program volunteers continue to collect water samples and take water clarity readings from 84 sites on the lake.
Results from specific locations around the lake may vary significantly from the lake-wide averages. Detailed results are posted at the SMLA website at www.smlassociation.org, where you can view the results from each of eight zones on the lake.
In addition to the samples collected by volunteers, scientists from Ferrum College collect bi-weekly water samples at 14 locations on the lake and test them for the presence of bacteria. In the week ending June 20, all samples were well within the Virginia Dept of Environment Quality guideline for bacteria in recreational waters.
Despite the good news coming from the water quality monitoring program so far this season, residents and visitors to the lake are reminded to always be aware of the possibility of algae blooms forming in any body of water. The Virginia Department of Health (VDH) advises keeping children and pets out of natural waters that have a green or bluish-green film. More information is available at the “Be HAB Aware” section of the SMLA website.
About SMLA
The Smith Mountain Lake Association (SMLA) mission is to keep Smith Mountain Lake clean and safe. Established in 1969, SMLA is the longest serving advocate for the SML community. Activities help to retain the pristine beauty of Smith Mountain Lake and the vibrant local economy. SMLA is a nonprofit 501(c)(3), volunteer-led organization that relies on memberships, donations and grants to support programs that protect SML.
The SMLA Water Quality Monitoring program is conducted in collaboration with Ferrum College. Photo Credit: Bob Pohlad
