820 (2015 - 524, Oct. 7) Public Notice

(2015 - 524, Oct. 7) Public Notice

The Washington Department of Fish and Wildlife intends to rehabilitate Rat Lake, Mouse Lake, Big Green Lake, and Little Green Lake in Okanogan County during the week of October 18th-24th, 2015.

Lake rehabilitation involves the treatment of the lake water with the pesticide rotenone to eradicate undesirable species of fish. Rotenone is non-persistent in the environment and non-toxic to humans or livestock at levels used to eradicate fish. The undesirable species of fish in Rat and Mouse lakes are bullhead catfish and crappie, and bluegill in Big and Little Green Lakes. These species have overpopulated the respective lakes and have rendered the stocked-trout fisheries ineffective and economically unfeasible.

Rotenone is a naturally-occurring and organic compound. The form of pesticide and active ingredient to be used are powdered rotenone at =8.7% active ingredient and liquid rotenone at 5% active ingredient. The targeted total concentration of rotenone in Rat and Mouse lakes will be less than or equal to 4 parts per million and in the Green lakes will be less than or equal to 2 parts per million.

Notices will be posted at public boat launches, and other areas of normal public access to the water. Please obey the following water use restrictions within the posted treatment area:

1)Do not use dead fish for food or feed.

2)Do not use water treated with rotenone to irrigate crops.

3)Do not consume treated water until the Department has notified you that the active rotenone concentration is less than 40 parts per billion (0.04 parts per million). This usually takes four to six weeks.

4)Do not swim in the lake until the application has been completed and the rotenone has been thoroughly mixed in the water.

The above list details the water use restrictions applicable to Rat, Mouse, Big Green, and Little Green lakes for the duration of rotenone toxicity. Rotenone toxicity will persist for 3 to 8 weeks. Water use restrictions will be removed when the lake detoxifies.

For more information concerning the treatment, contact the applicator, Washington Department of Fish and Wildlife, District 6 Fish Biologist: Ryan Fortier at 509-997-0316.

This pesticide treatment is regulated under permit by the Washington Department of Ecology Water Quality Program, Eastern WA Regional Office (509) 456-2926. These pesticides have been approved for this purpose by the Environmental Protection Agency and the Washington Department of Agriculture. Published by Omak-Okanogan County Chronicle.


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