Manitoba Water Stewardship advises that testing has shown that levels of Escherichia coli (E. coli) were within recreational water quality guidelines at most beaches monitored this week by the department.
Escherichia coli counts were above the guideline at St. Malo Beach and Plum Coulee Reservoir Beach on Aug. 18. Results from re-sampling are expected late this afternoon and will posted as soon as they become available on the department’s website.
Sampling results from Big Whiteshell Lake and Lake Wahtopanah (Rivers Reservoir) on Aug. 14 indicated the algae blooms have dispersed somewhat and the number of blue-green algae cells has returned to below the recreational water quality guideline of 100,000 cells per ml. Algae advisory signs will remain posted for the rest of the season to let bathers know that algae blooms have been observed at the beach and to provide some additional advice regarding avoiding contact with the water when algae blooms are present. In the absence of a severe algae bloom, recreational activities are considered safe.
Algal samples collected from Killarney Lake on Aug. 18 indicated the number of blue-green algae cells was above the proposed recreational water quality guideline of 100,000 cells per ml. The beach was posted with an algae advisory on July 24. The concentration of the algal toxin, microcystin-LR, was below the guideline.
Algae blooms often appear in Manitoba lakes at this time of the year and can last until mid-September. The formation of algae blooms is difficult to predict however warm and calm weather coupled with relatively high nutrient loads create ideal conditions for their development. Swimmers are reminded to avoid swimming in water if severe algae blooms are visible.
Each summer, Manitoba Water Stewardship routinely monitors about 60 beaches in Manitoba.
