DNAPL migration in a coastal plain aquifer

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:215561

DiGuiseppi, W H; Jung, A D ^[1]

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1. Consoer Townsend Envirodyne Engineers, Inc., Fairfax, VA (United States)

Soil and ground water at the Dover Gas Light Superfund Site, a former manufactured gas plant (1859 to 1948), are contaminated with polynuclear aromatic hydrocarbons and volatile organic compounds. Contaminants of concern include light aromatics, such as benzene, toluene, ethylbenzene, and xylenes (BTEX), and heavy aromatics, including naphthalene, acenaphthylene, phenanthrene, and benzo(a)pyrene. Although ground-water contaminant levels are elevated near the site, only naphthalene and acenaphthylene are present within an order of magnitude of their solubility limits, indicating the possibility of dense non-aqueous phase liquids (DNAPL) in the subsurface. The unconfined Columbia Aquifer, which is characterized by interfingering and discontinuous sand, silt, and clay Coastal Plain deposits, overlies a clay aquitard at a depth of 60 feet. The ground water beneath the intermediate clay horizon exhibited little or no contamination, even immediately downgradient from the site. The relationship between the more permeable granular sand horizons and the less permeable interfingering clay zones controls the migration of both the aqueous-phase contamination and the DNAPL. A detailed horizontal and vertical characterization of the subsurface stratigraphy was critical to the accurate interpretation of the extent and magnitude of contamination and the identification and delineation of DNAPL zones.

• OSTI ID: 215561
• Report Number(s): CONF-951139--
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
ACENAPHTHENE
ALKYLATED AROMATICS
AQUIFERS
BENZENE
BENZOPYRENE
COAL GASIFICATION PLANTS
DATA
DELAWARE
ENVIRONMENTAL IMPACTS
ENVIRONMENTAL TRANSPORT
NAPHTHALENE
PHENANTHRENE
TOLUENE
US SUPERFUND
WATER POLLUTION
XYLENES