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    Complimentary Article

    Update to the Light Nonaqueous Phase Liquid Infiltration Conceptual Model

    Authored by Roux's Martin J. Hamper, P.G. & Mir SeyedAbbasi, Ph.D., P.E.

    The 1970s oil spill model has described the infiltration of oil (light nonaqueous phase liquid or LNAPL) into the subsurface resulting in an oil pancake depressing the water table within the capillary fringe. An update to the 1970s model is needed because, according to the discussion by Lenhard et al., "LNAPL-saturated 'pancakes' do not exist." Some key points of this article include:
    • The updated oil spill infiltration conceptual model includes LNAPL penetration of the water table to a depth consistent with the gravitational and capillary forces experienced during LNAPL infiltration, resulting in the coexistence of both the LNAPL table and the water table within the two-fluid zone.
    • The elevations of the LNAPL table and the water table within the two-fluid zone can be calculated from fluid levels in a monitoring well.
    • The LNAPL-water capillary pressure head portion of the LNAPL baildown test recovery profile represents a portion of the test period where only one fluid, LNAPL, is entering the well, which is consistent with Huntley’s baildown test equation assumptions.
    This research article is published in Remediation Journal. To view this article, please complete the form.