Vertical distributions of water and light nonaqueous phase liquid (LNAPL) from a well documented aviation gasoline spill at the US Coast Guard Air Station in Traverse City, Michigan were measured. Two field sampling methods for the determination of LNAPL content were presented. Existing models for the free and residual LNAPL profiles described the data with calibrated error standard deviations ranging from 14 to 23% in magnitude. A field trapping protocol was also developed with sample ports fabricated in the intact core sleeves as part of the trapping method, which yielded total hydrocarbon concentration data consistent with independent data from a tubing cluster. The evaporation of 2,2,4 trimethylpentane and 2,2,5 trimethylhexane vapors from the LNAPL was measured in the laboratory under diffusive and advective conditions to simulate soil venting and sparging. The data and theory suggested that lower soil venting or sparging flow rates were in principle as effective as higher rates in stripping gasoline vapors from contaminated soils. The biodegradation of hydrocarbon vapors in soil microcosms obtained aseptically from the site was also documented.

"Jong Soo Cho, project officer." "December 1992." Includes bibliographical references (pages 114-120). "EPA/600/R-92/247." "Project No. CR-816821." Microfiche.