FREE PRODUCT RECOVERY AT AN INDUSTRIAL SITE

An underground storage tank used for storing used kerosene, was removed from an industrial facility in 1989. Light Non-Aqueous Phase Liquids (LNAPL) were noted in monitoring wells in the vicinity of the former tank, and the site fell under the jurisdiction of Ohio's Bureau of Underground Storage Tank Regulations (BUSTR) in 1994. Free-product recovery activities have been ongoing since 1994 with limited progress towards BUSTR's criteria for receiving No Further Action status: the absence of measurable LNAPL for 3 consecutive months.

Active free product recovery pumps were installed in 2007, but failed to materially change the free product thicknesses observed at target monitoring wells. Recently, BUSTR informed our client that the site was not showing satisfactory progress and that additional measures were necessary. The preponderance of data available regarding the site which includes dozens of monitoring wells and soil borings as well as over a decade worth of fluid level measurements provides a unique opportunity to retroactively assess our approach to the site. This presentation aims to provide a critique our efforts. It will also serve as a guide for future LNAPL projects. The lessons learned at the site can help evaluate remedial approaches at future LNAPL sites.