Site investigations of fuel spill migration into permafrost

In the summer; of 1995 and 1996 subsurface investigations were conducted to examine the vertical migration of petroleum hydrocarbons into the permafrost at two different sites in the Canadian Arctic where fuel spills had previously occurred: Canadian Forces Station Alert on the Northern tip of Ellesmere Island, and Isachsen High Arctic Weather Station on Ellef Ringnes Island. Petroleum hydrocarbon contamination was found below the permafrost table in excess of 1.5 m at Alert, and in excess of 0.6 m at Isachsen, both depths being the maximum depths of the investigations. This paper provides the detailed results of these investigations with an explanation of the expected transport mechanisms. The results show that the permafrost may not be an impermeable barrier to nonaqueous phase Liquid (NAPL) contamination under some circumstances.