A simple one-dimensional model describes the mobilization of 90 cu m of residual aviation gasoline from an 80-m diameter, 0.306-m thick contaminated soil mass at the US Coast Guard Air Station in Traverse City, Michigan. Originally deposited under a paved ground surface in December 1969, the bound product is thought to be entrained as a separate phase by episodic incursions of the water table in the assumed absence of dissolution, biodegradation, and volatilization. The coupled transport processes of storage, advection, and water table flushing govern the gasoline concentration subject to a presumed linear sorption relation between mobilized and stationary residual phases. A retardation factor of 13.1 calibrates soil-core data taken at the site from August 1987 to December 1988, with a standard deviation of 26%, indicating a reasonable degree of accuracy. The present position of the leading edge of contamination endorses the calibrated retardation factor value as well.