Impacts of Remediation at the Bemidji Oil-Spill Site

By William N. Herkelrath

ABSTRACT

The U.S. Geological Survey has conducted a multidisciplinary investigation of the fate and transport of subsurface petroleum hydrocarbons at the site of crude-oil spill near Bemidji, Minnesota, since 1983. For 19 years, the Bemidji site provided a unique natural laboratory for scientists to study a subsurface oil spill that was virtually undisturbed. However, in order to ensure compliance with the law, Minnesota State authorities have recently mandated oil-recovery remediation of the site. The aim of the remediation is to remove the separate-phase oil that is presently located near the water table. In this paper, simple models were used to obtain first-order estimates of how much subsurface oil is now present at the Bemidji site, and how much oil is likely to be recovered during the remediation. These preliminary results indicate that about 241,000 liters of oil are now present, and about 41,000 liters (17% of the present oil volume) will be recovered during the remediation.