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DHS news release

March 11, 2004

Contact: Bonnie Widerburg (503) 731- 4180
Technical contact: Ken Kauffman (503)731-3462

Algae Toxin Advisory Lifted for Ten Mile Lake

A health advisory regarding recreational contact because of algae toxins in Ten Mile Lake, 10 miles north of Coos Bay, has been lifted by public health officials in the Oregon Department of Human Services (DHS) and the Coos County Health Department.


The advisory went into effect on Sept. 22, 2003. The algae bloom has since declined and toxin levels should be well below hazardous levels, according to Ken Kauffman, environmental specialist in DHS.

Kauffman said that subsequent tests showed levels well below those likely to be associated with dangerous toxin concentrations in the water.

"Even though the recreational advisory is lifted, persons who use water from the lake for household purposes should continue to filter and disinfect the water," Kauffman said. "Surface water needs to be filtered and disinfected at all times to be safe for drinking and food preparation."

Kauffman advises that people who live at the lake or who use it recreationally should always be alert for visible signs of algae blooms. If the water is green or bluish green in color or if there are visible clumps of algae in the water, then water contact should be avoided by humans and animals. Drinking the water is the most direct route of exposure, but harmful effects can occur during or after skin contact if there are algae toxins in the water.

Summer temperatures, calm air conditions and bright sunshine along with high nutrient levels in lake water are believed to lead to the rapid growth of algae known as "blooms." During bloom periods, there can be dangerous levels of toxins produced by some species of freshwater algae. The 2003 algae bloom was moderate compared to blooms in some earlier years, according to Kauffman.

A fact sheet about Microcystis aeruginosa and detailed recommendations for lake water treatment may be obtained from Ken Kauffman at (503) 731-3462 or via E-mail at kenneth.w.kauffman@state.or.us or from the Coos County Health Department at (541) 756-2020.