REMEDIATION AT THE FLINT HILLS RESOURCES PINE BEND REFINERY: THREE DECADES OF REMEDIAL RESPONSE AND SUCCESS

In the late 1990s, a number of historic releases of petroleum were discovered at the Flint Hills Resources (FHR) Pine Bend Refinery (Refinery) in Rosemount, Minnesota. The largest releases occurred in an area where the regional groundwater table intersected a weathered zone of carbonate bedrock allowing the petroleum products to migrate further and more rapidly than typical petroleum releases, in areas where the water table occurs in unconsolidated deposits or competent bedrock. This zone, referenced as The Bedrock Mechanism by FHR, their consultants, and the Minnesota Pollution Control Agency (MPCA), required the design and implementation of a unique Site Remediation approach. With the involvement of all stakeholders during the remediation process, the site has seen tremendous success with the mitigation of petroleum migration and reduction of petroleum mass, which includes the closures of several remediation systems.