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Contaminants in Sediment Cores

Ecology collects sediment cores from three lakes per year for an ongoing study to evaluate PBT chemical trends in Washington State. Target analytes include lead, mercury, and organic contaminants, such as PAHs, depending on year of study.

See the Project Plan and Addendum for more information.


  • 2015 Results from Lake Meridian, Lake Whatcom, and Williams Lake.
  • 2014 Results from Bead Lake, Lake Goodwin, and Mason Lake.
  • 2013 Results from Lake Cavanaugh, Kitsap Lake, and Lake Sawyer.
  • 2012 Results from Deer Lake, Lake Stevens, and West Medical Lake.
  • 2011 Results from Angle Lake, Samish Lake, and Lake Nahwatzel.
  • 2010 Results from Lake Wenatchee, Lone Lake, and Sprague Lake.
  • 2009 Results from American Lake, Black Lake, and Upper Twin Lake.
  • 2008 Results from Lake Washington, Lacamas Lake, and Offutt Lake.
  • 2007 Results from Walupt Lake, Loon Lake, and Wannacut Lake.
  • 2006 Results from Lake Ozette, Lake Sammamish, and Lake St. Clair.


Click on map to retrieve Sediment Core data from the EIM database.