One swim advisory has been lifted, but several beaches remain closed in Orange County’s largest residential neighborhood.
Late last month, the cove area of the 500-acre Main Lake was placed under a swim advisory due to a sewage overflow near the 1200 block of Lakeview Parkway. According to Lake of the Woods personnel, the overflow occurred on a private lot and made contact with a surface water connection to the Main Lake. “Out of an abundance of caution” a swim advisory was issued. Swimmers were advised to engage in water activities at their own risk until test results confirm concentrations.
Results from water samples collected July 27 were released Monday. According to the samples the E.coli concentration where the stream inlet reaches the lake was 122.3 MPN/100mL. Samples collected leaving the cover were lower. An MPN (most probable number) is similar to a CFU (colony forming unit). The threshold, according to the Virginia Department of Health, for issuing a beach advisory is 235 CFU/100mL.
As a result the swim advisory for the cove area has been lifted.
However, a new beach closure has been issued for Harper’s Ferry Beach, which is located on the Main Lake. Water samples collected July 31 revealed E.coli concentrations of 613.1 MPN/100mL, more than double the threshold for beach advisories.
In addition, Cumberland Beach on the 24-acre Keaton’s Lake remains closed due to harmful algal bloom conditions. Testing was conducted on samples collected July 23 from three sampling sites in Keaton’s Lake. Those tests determined an average of 61,366 cells/mL of potentially toxigenic cyanobacteria. The neighborhood’s protocol sets a closure threshold of values greater than 50,000 cells/mL.
Water quality testing is ongoing. Results from samples collected last week are expected by Aug. 8.
