Publication Summary

This is the study plan for the Depositional History of Mercury in Selected Washington Lakes Determined from Sediment Cores.

The Washington State Legislature provided funding in 2005 to the Washington State Department of Ecology (Ecology) Persistent, Bioaccumulative and Toxics (PBT) Reduction Strategy to develop a long-term monitoring program for mercury in freshwater systems. The primary objective of this project is to evaluate mercury deposition through the use of age-dated sediment cores.

All lakes in Washington are likely being impacted by the global pool of atmospheric mercury. Selection of lakes to include in the study will be based on potential impacts from local sources of mercury and other issues of importance to local and state environmental managers. A total of three lakes will be evaluated each year of the study.

During the summer of 2006, Ecology will collect sediment cores and surface sediments from (1) Lake Ozette, located in the northwest corner of the Olympic Peninsula, (2) Lake Sammamish in east King County, and (3) Clear Lake in southeast Thurston County. The three selected lakes will reflect potential impacts from the trans-Pacific transport of mercury from Asia, a large urban/industrial/residential area of Seattle, and the only coal-fired power plant in Washington State, respectively.

Cores will be age dated using lead210 techniques. Sediment analysis will include total mercury, total lead, lead210, total selenium, total organic carbon, and grain size.

Link to EIM data for User Study ID RCOO0007