Fernan Lake algae blooms prompt DEQ water study

The Idaho Department of Environmental Quality could have lab results today from tests of blue-green algae samples from Fernan Lake.

People may want to avoid swimming in the lake and not let pets drink the water in the meantime, said June Bergquist, a water quality compliance officer with the DEQ.

The plants, growing in a brownish mass in the shallow lake, were tested after residents raised concerns about possible health and safety risks.

“There are certain species that produce toxins dangerous to pets that may drink the water,” Bergquist said.

Swimmers could wind up with itchy, irritated skin.

If the toxins from the algae are high enough, the DEQ could advise against eating fish from the lake while the algae are in bloom.

Tom Torgerson said he noticed the brownish mass while looking down at the lake from the deck of his Fernan Hill Road home last week.

The next day his wife, KJ, was swimming in the lake and told him the plants were so thick that she couldn’t see her hands two to three inches under the water.

“This bloom is so dense and severe that it makes swimming in the lake undesirable and possibly harmful to your health,” Torgerson said in a letter to the DEQ, the Idaho Department of Fish and Game and others.

He attached pictures of the brown bloom and pictures of water samples he had taken from the lake.

The pictures of lake water, inside a plastic bottle, show a light-brown substance floating on the top.

Torgerson said the heaviest concentration is on the southern shore of the lake but the algae are spreading to other areas.

The algae stem from an excess of nutrients in the lake, Bergquist said.

Fernan Lake is in a fragile state. A 2003 lake management study found it’s on the verge of becoming eutrophic, meaning algae and other plants are taking over much of the lake, using oxygen that fish and other organisms need.

“We’ve got to figure out how to save that lake before the lake dies,” Torgerson said.