Milfoil program under way on lake

SANDPOINT — Three Eurasian milfoil infestations in Lake Pend Oreille were slated to be treated with herbicides on Tuesday.

The 62 acres of treatment area will be split among three sites — a clot beneath the Long Bridge, Bottle Bay in Sagle and Ellisport Bay near East Hope. Signs have been posted on affected properties to advise the public of the chemicals being used and water use restrictions, according to Aquatechnex, the contractor hired by Idaho State Department of Agriculture to conduct the applications.

Public notices have also been delivered to homes adjacent to and within a buffer zone distance along the shoreline, Aquatechnex said.

Maps of the treatment areas have been posted on Aquatechnex’s treatment program blog (http://pomilfoil.com).

All three sites will be treated with triclopyr, although the treatment at the Long Bridge will be augmented with Endotholl, said Terry McNabb, an aquatic biologist with Aquatechnex.

McNabb said the treatment areas are not near any municipal water intakes, although there are some landowners draw water from the lake for personal use. Those affected landowners will be restricted from pulling water from the treatment areas until the herbicides dissipate.

“That generally happens in 2-4 days with these products,” McNabb said in an e-mail to The Daily Bee.

ISDA has taken the lead on treating Pend Oreille milfoil, which the department considers to be one of the toughest to treat in the nation because of depths, water exchange, drinking water intakes and upstream infestations.

This year, ISDA directed its efforts on beating back milfoil in high-use, high-priority areas.

Divers have wrapped up their work pulling low-density milfoil patches at Windbag Marina and City Beach.

The state treated around 30 acres at Priest Lake’s Bear Creek Bay and a post-treatment survey was scheduled for this week.

Divers are still working at Priest Lake, where they located six previously undocumented infestations. Despite the discovery, Erin Mader of the county’s Aquatic Invasive Species Task Force is optimistic the infestations can be held in check.

“There’s a hope that we can keep it to a bare minimum on Priest,” Mader said during last week’s Waterways Advisory Board meeting in Coolin.