Remediation-Surfactant-Enhanced Free Product Recovery
Due to the former wide-spread use of heating oil throughout the country and the corresponding use of USTs to store the oil, many sites today are faced with varying degrees of impacts associated with leaks from these obsolete tanks. One such site, located near the lakefront in the City of Chicago, experienced a release of #5 heating oil which migrated beneath the on-site 14-story residential building and leaked into the adjacent basement through cracks in the walls and floor, yielding the property nearly unmarketable. When the release was first discovered in 1990, two separate consultants were hired to perform corrective action at the site but were unsuccessful due to design short-comings and the viscous nature of the heating oil released from the tank. Pioneer was subsequently contracted to develop and implement a strategy to remove the oil from beneath the building. Pioneer’s involvement in this project facilitated the subsequent sale of the building, which was in-part based on the completion of Pioneer’s IEPA-approved Corrective Action Plan for the site.
Pioneer began solving this problem by designing and performing a subsurface investigation beneath the high-rise building to delineate the extent of freephase #5 heating oil associated with the out-of-service 15,600 gallon UST. Once the extent had been defined, Pioneer designed, implemented and interpreted an aquifer pumping test to determine the hydrogeologic characteristics of the subsurface and determine appropriate remedial strategies for the site. Since the main problem associated with recovering the oil was its viscous nature – no product was recovered during the pumping test, Pioneer designed, constructed and operated a benchscale model to economically determine the technical feasibility of using heat and/or surfactants to recover the viscous #5 heating oil from beneath the structure. Upon successful results of the benchscale modeling, Pioneer performed an on-site pilot test to determine the site-specific parameters for a surfactant-enhanced free product recovery system at the site. Pioneer subsequently designed, constructed, and performed operations and maintenance on a fullscale surfactant-enhanced product recovery system at the site to recover an estimated 3,000 gallons of #5 heating oil.
As a point of interest, during the operation of the system, Pioneer entertained 12 IEPA representatives at the site who were interested in personally inspecting the site due to its innovative and effective product recovery strategy. Pioneer also procured client reimbursement from the State UST fund for eligible investigation and corrective action costs at the site.