ARS Installs 90-foot Deep FeroxSM System to Treat Chlorinated VOC Source Zone
 Recently,
ARS completed the installation of a pilot
scale FeroxSM system to treat a
CVOCs source area with TCE and 1,1,2,2 PCA
at a former military facility in Tennessee.
The pilot test consisted of a grid of 4 injection
wells to emplace 25,000 pounds of ZVI within
the subsurface. During the injections, pressure
influence at a distance of more than 25 feet
was observed. Sampling results three months
after the injections showing 1,1,2,2 PCA concentrations
to have been reduced by as much as 93% from
a maximum of 40,800 ppb to 3,010 ppb within
the center of the treatment zone. The majority
of the monitoring points within the treatment
zone have shown at least a 90% reduction in
1,1,2,2 PCA levels within the 3-month post-injection
monitoring timeframe. This project also represented
the first
field application of our new integrated deep
well drilling/injection method. Using
sonic drilling, a pressurized water column
advanced a 4-inch casing to the target injection
depth in each hole. Once at depth, atomized
slurry injections were applied to the formation
as the casing was retracted from the hole.
This innovative method offers several key
advantages over conventional injection methods
including the ability to apply materials/chemicals
at depths of several hundred feet, applicability
in virtually all soil types, greatly reduced
quantity of soil cuttings, reduced field personnel
exposure to hazardous chemicals and the benefit
of providing a very effective seal to facilitate
good emplacement of the material into the
subsurface.
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