The Grand River Dam Authority is reporting that its most recent monitoring of a confirmed blue green algae (BGA) bloom in Grand Lake’s Ketchum Cove shows that the bloom, present from near the Hammerhead Marina boat ramp to near Colony Cove, has decreased both in size and in toxicity levels in some portions. However, GRDA continues to advise the public to use extra precaution in this area of the lake as the bloom can concentrate as it is pushed by the wind and waves.
Most recent testing by GRDA shows the bloom varying in toxin levels from 16.69 micrograms per liter (ug/l) to >50 ug/l in areas where scum has accumulated. Environmental Protection Agency (EPA) guidelines, published in 2019, recommend no primary body contact with the water when microcystin concentration produced by the BGA is greater than eight micrograms per liter (>8ug/l
At this time, GRDA has not confirmed BGA in any other areas of Grand Lake.
“Again, we want the public to be aware that the overwhelming majority of Grand Lake does not show any signs of BGA and is ready for visitors to come and enjoy,” said GRDA Corporate Spokesperson Justin Alberty. “We will continue our daily testing and surveys all across the lake and provide updates when they are available.”
BGA may resemble thick pea soup, lime green or blue green paint or in some cases bluish, brownish, or reddish-green paint. When BGA washes up on shore, it can form a thick mat on the beach. BGA can reproduce rapidly in water bodies with adequate amounts of sunlight and nutrients such as phosphorous and nitrogen. It is recommended that individuals avoid swimming or participating in water recreational activities in areas where the water is discolored or where you see foam, scum, or mats of algae on the water.
If you see a BGA bloom, ODEQ recommends that you avoid all contact with the water, keep your pets and livestock away from the water and immediately contact ODEQ at (800) 522-0206 or GRDA at (918) 256-0911.