skip to main content

Natural Resources and Parks

King County, Washington

For questions about King County Natural Resources and Parks website, please contact Fred Bentler, webmaster.

March 9, 2011

King County plans treatment at Lake Hicks to curb potentially harmful algae blooms

March 22 public meeting provides details of scheduled aluminum sulfate treatment

King County is developing a plan to help improve water quality in White Center’s Lake Hicks so that people and pets are safe from potentially harmful algae blooms in the small lake.

The King County Water and Land Resources Division has set a public meeting for March 22 at the White Center Library to share information on a scheduled treatment of aluminum sulfate in Lake Hicks. The meeting is set for 6:30-8 p.m. at the White Center Library, 11220 16th Ave. SW, Seattle.

The Washington State Department of Ecology has identified Lake Hicks as having “impaired” water quality because of excessively high phosphorus concentrations, which promote frequent algae blooms in the lake.

These algae blooms have produced biotoxins that are potentially harmful to people and pets that come into contact with the water. As a result of the algae blooms, warning signs have been posted along the Lake Hicks shoreline during the recreational season to alert people of the potential danger of contact with the water.

To address this ongoing water quality problem, King County has received a permit to treat the lake in May with aluminum sulfate to lower phosphorus concentrations in the water and “cap” the phosphorus-rich sediments. A similar action was taken at Lake Hicks in 2005.

More information about lake stewardship in King County is available at

Related information

Lake Stewardship

King County Water and Land Resources