 In
situ iron permeable reactive barriers (PRBs) are replacing pump
and treat remedies for contaminated groundwater with life cycle
cost savings greater than 75%. Iron PRBs remediate groundwater contaminated
with chlorinated compounds by abiotic degradation of the halogenated
volatile organic compounds into non-toxic end products. Also, numerous
heavy metals are removed from groundwater by zero valent iron.
Azimuth oriented vertical hydraulic fracturing is an established
technology of placing iron reactive barriers in situ, resulting
in significant cost savings and allowing reactive barriers to be
installed at far greater depths than conventional technologies. Controlled
vertical hydraulic fracturing technology has been used to install
PRBs at a number of sites in highly permeable sands, gravel and
cobbles down to moderate depths; in a number of cases greater than
100 ft bgs.
The in situ PRBs are constructed from a series of wells installed
along the PRB alignment. A controlled vertical fracture is initiated
in each well at the required azimuth orientation and depth. Iron
filings are injected into the wells in a highly viscous cross-linked
proprietary HPG gel, to form a continuous PRB.
The PRBs geometry is monitored in real time by GeoSierra’s
patented active resistivity method to ensure the barrier is constructed
as designed. |
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Major cost savings. |
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Minimal site disturbance. |
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No excavation of contaminated material. |
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Deep application of treatment technology. |
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Minimal impact on groundwater flow regime. |
