DIRECT
INJECTION APPROACH:
The Newman Zone amendment may be injected to establish a reactive barrier
wall and/or directly into contaminant source area soils to accelerate
anaerobic processes.
The emulsified oil phase of the Newman Zone amendment adsorbs onto source area soils allowing it to produce stimulation of anaerobic processes for years with a single injection.
A site specific injection plan needs to be prepared that balances the need to distribute amendment solution within the source area soils without mobilizing contamination from the source area and expanding the area of dissolved phase contamination. Such a plan could include placement of a downgradient permeable reactive barrier.
In most cases, the use of a ground water recirculation system will favor the use of less expensive electron donor amendments such as simple sugars, alcohols, and organic acids. For sites where a high advective flow velocity is produced between injection and extraction wells, the short period of time that these rapidly consumed amendments persist may be acceptable. For lower flow systems where more than a month is needed for full circulation, the use of the Newman Zone amendment may be favored. As the amendment is distributed by recirculation and adsorbed onto site soils, it may be possible to perform infrequent batch additions while leaving the pumping system off the majority of the time. This could lead to a substantial savings in operations and maintenance costs, which would off-set the somewhat higher cost of the Newman Zone electron donor.