Authors: Wilson, David; Rudolfo, Nicholas; Noble, Bruce; Lally, John; Hewitt, Ronald; Kim, Kay; Grover, Barry.
Reference: Wilson, David; Rudolfo, Nicholas; Noble, Bruce; Lally, John; Hewitt, Ronald; Kim, Kay; Grover, Barry (2014) Implementation of a Thin Layer Cap on Lake Superior in Marathon, Ontario, Presenation RPIC-FCS Workshop April 14-16, 2014 Ottawa
Summary: The presentation gives the historical contaminantion sources on the site, these date back to 1946. Investigations, dating back to 1980, have measured elevated mercury and PCBs in Cove sediments. It has been deetermined that the sediments are not toxic to benthic organisms, but affect upper trophic communites including the reproductive success of bottom feeding fish. Options considered at this site have included dredging and capping alternatives. Presence of higher levels of contamination at depth and risk of resuspension were concerns with dredge options. It was determined that the thin layer sand cap provided the adequate risk reduction and enhanced natural recovery of the site. the prescribed remedy for the site is placement of 15 – 20 cm layer of clean sand over defined contaminated “hot spots”.
What You Will Find Here: Slides: Construction p. 13; Monitoring p. 20