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Ground‐Water Contamination by High‐Density Immiscible Hydrocarbon Slugs in Gravity‐Driven Gravel Aquifers
Author(s) -
Corapcioglu M. Yavuz,
Hossain M. Akhter
Publication year - 1990
Publication title -
groundwater
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.84
H-Index - 94
eISSN - 1745-6584
pISSN - 0017-467X
DOI - 10.1111/j.1745-6584.1990.tb02270.x
Subject(s) - aquifer , saturation (graph theory) , density contrast , plume , sink (geography) , geology , water table , groundwater , hydrocarbon , viscosity , diel vertical migration , soil science , petroleum engineering , geotechnical engineering , chemistry , thermodynamics , physics , oceanography , mathematics , cartography , organic chemistry , combinatorics , astronomy , geography
In contrast to light hydrocarbons like gasoline that float on the water table, high‐density chlorinated hydrocarbons such as TCE and TCA released to the environment sink into the aquifer and remain at the bottom for extended periods of time. The migration of these hydrocarbons is generally governed by the vertical component instead of lateral transport as for low‐density hydrocarbons. The Buckley‐Leverett approach is extended to a two‐dimensional case to simulate the migration of a high‐density hydrocarbon displacing ground water in a highly pervious gravity‐driven natural‐gradient gravel aquifer. Governing equations are solved by modifying the USGS solute transport model (Konikow and Bredehoeft, 1978). The modification incorporates the fractional flow curves of water and their saturation derivatives in vertical and horizontal directions as functions of degree of water saturation. As an example, a contamination incident representing a TCE spill from a storage tank buried in the saturated zone is considered. Numerical results show that high‐density, low‐viscosity immiscible chlorinated hydrocarbons can travel deeper and further in contrast to lower‐density, higher‐viscosity compounds, and that the migration is dominated by gravity‐driven vertical flow until the plume reaches the lower boundary.