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.