The Grand River Dam Authority is reporting the presence of a blue green algae (BGA) bloom in the Ketchum Cove area of Grand Lake. Water quality testing performed recently by the GRDA Ecosystems and Watershed Management Department confirmed the bloom.
On Wednesday (July 6), a BGA bloom could be seen extending from near the Hammerhead Marina boat ramp eastward toward Colony Cove. GRDA is advising the public to use extra precaution in this area of the lake as the situation can change rapidly and the bloom can concentrate as it is pushed by the wind and waves. 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). The latest sampling shows the toxin levels in this area ranging from 7.1 to >50 ug/L depending on the location within the cove and density of the algae.
BGA may resemble thick pea soup, green paint or 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.
“Although most algae blooms are not toxic, toxins can be produced in some algae blooms dominated by Blue Green Algae,” said GRDA Corporate Spokesperson Justin Alberty. “We have communicated these test results to the Oklahoma Tourism and Recreation Department, the Oklahoma Department of Environmental Quality, and the Oklahoma Water Resources Board. Right now, we are closely monitoring the area and will provide regular updates as the situation progresses.”
No BGA has been confirmed in any other areas of Grand Lake.
“Grand is a large lake, with plenty of room for the public to come out and enjoy,” said Alberty. “We encourage everyone to play safe and please be aware of this current BGA presence.”
According to the Oklahoma Department of Health, exposure to BGA can cause skin irritation, including rashes, hives or blisters. Inhalation of BGA can also trigger asthma-like conditions or allergic reactions. Finally, ingestion of BGA water can cause stomach cramps, nausea, diarrhea, or vomiting. Due to their body size, young children are especially susceptible to the effects of BGA. It is also important to keep pets from drinking and swimming in water containing BGA water.
Municipalities that draw raw water from this area should be taking the necessary steps to ensure the quality of their water by utilizing their water treatment systems, and lake residents who draw water from this area should avoid consumption of and contact with the water until further notice. Simply boiling water that may contain BGA does not remove the toxins from 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.
Oklahoma State Department of Health- Public Health Fact Sheet