Bioremediation of Hydrocarbon-Contaminated Soils
and Groundwater in Northern Climates
CHARLES M. REYNOLDS, W. ALAN BRALEY, MICHAEL D. TRAVIS,
LAWRENCE B. PERRY, AND ISKANDAR K. ISKANDAR
laboratory results to the field, our ultimate goal,
INTRODUCTION
is difficult to quantify. Obtaining a good under-
standing of the degradation rates at a field site is
Background
Many contaminated-soil sites in cold regions
hindered by the inherent variability in field bio-
are isolated and remote. These factors, combined
logical studies.
with extreme climatic conditions, make bio-
Landfarms are readily constructed and pro-
remediation difficult. Although there are increas-
vide relatively easy sampling, although the soil
ing choices of in-vessel bioremediation schemes
mixing that is achievable is usually not uniform
available, these often rely on extensive equip-
across an entire landfarm. Regulatory restrictions
ment needs and large energy inputs. For use at
generally prevent intentional application of
remote sites in cold regions, a cost-efficient and
petroleum to soils and thereby inhibit studying
applicable technology would necessarily be char-
the effects of different treatments applied to a
acterized by low input and rugged design. Bio-
"uniformly" contaminated soil. To counter this,
remediation encourages natural soil-mediated
random samples can be taken and composited,
processes by addressing the limiting factors. It
but unless this process is replicated sufficiently,
may be a preferred technology for remediating
estimates of variability, and therefore estimates
contaminated soils in severe climates, such as the
of the net effects of treatments taken from the
Arctic and sub-Arctic regions of Alaska or other
laboratory, can not be made successfully.
cold regions, and potentially could be used to
We have incorporated the spatial variability
treat the bulk of the contaminated soils at these
into the monitoring scheme in the landfarm.
remote sites. Although bioremediation of con-
Process monitoring is more difficult in subsur-
taminated soils is a proven and frequently used
face systems, owing to the costs of obtaining
technology in more temperate regions, the con-
samples and the limited access to the soil treat-
straints imposed by severely cold climates, where
ment zone. For the infiltration gallery's subsur-
the season for optimum bioremediation condi-
face system, we used traditional well monitoring
tions typically is short, may reduce the cost
techniques. The recirculating leachbed design
benefits.
provided a more aggressive treatment than the
infiltration gallery, was a contained system, and
provided for better mixing than the infiltration
Objectives and rationale
gallery or landfarm.
for field research
To optimize bioremediation, it is necessary to
identify and reduce the factors that limit biodeg-
Project location
radation rates. Ways to reduce these limitations
The project site, located at the Fairbanks Inter-
are usually found through small-scale laboratory
national Airport (FIA) in Fairbanks Alaska, was
treatability tests, but the success of transferring
the previously used crash-fire-rescue (CFR) train-
Previous Page
