Chemical Characterization and Sources of Distillate Fuels in the Subsurface of Mandan, North Dakota

摘要

The source(s) of the non-aqueous phase liquid (NAPL) in the downtown area of Mandan, ND, has been investigated through a two-part study in which the detailed chemical compositions of: 1) the NAPLs from the downtown area and remote areas on a nearby rail yard (phase Ⅰ), and 2) residual petroleum in vadose zone and capillary fringe soils from borings near suspected sources (phase Ⅱ) have been determined. The NAPL and soils are shown to contain variably weathered middle distillate fuels. The distributions of n-alkylcyclohexanes (CHs) and relative abundance of sulfur-containing aromatics (alkyl-dibenzothiophenes), both of which are stable over the various degrees of weathering exhibited by the NAPLs in the study area, were of particular utility in characterizing these fuels. The data indicate that multiple types of middle distillate fuels exist(ed) in the downtown area, establishing multiple sources and releases to the subsurface.