A Solid Solution
results indicate, significant recovery of NAPL is potentially achievable. To this end, detailed
modeling of the surface of confining layers is useful to find potential NAPL pools
that may be recoverable.
Upon completion of the NAPL recovery, ISCO treatment of off-site source
material will be conducted. On the basis of results of a treatability study performed by XDD, LLC, of Stratham, New
Hampshire, it was decided to employ
catalyzed hydrogen peroxide as the ISCO
method. In particular, XDD determined
that a 12. 5 percent solution of catalyzed
hydrogen peroxide with 20 millimoles
of citric acid at 3. 5 g per kilogram of soil
would be the most effective and reliable
chemical for performing ISCO as part of
The treatability study indicated preferential treatment of benzene, toluene,
ethylbenzene, and xylenes (99 percent
removal efficiency) and, to a lesser extent,
polycyclic aromatic hydrocarbons and
(Continued from Page 81)
total petroleum hydrocarbons (
approximately 50 percent removal efficiency)
after four applications of ISCO on moderately affected soils. It is expected that
approximately 20 lb of oxidant will be
used per pound of contaminant in moderately affected soils. The XDD study also
indicated that more applications will be
required to treat the heavily affected soils
and that NAPL may migrate from the
contaminated intervals into less contaminated or noncontaminated intervals.
Therefore, continued monitoring and recovery of NAPL will be conducted during
and after the ISCO injection. Follow-up
soil and groundwater monitoring will be
performed for up to six months to evaluate ISCO effectiveness.
The time frame for completing the
remaining actions is not known. As for
the final phase of the prescribed reme-
dy, which involves the bioremediation
of dissolved-phase contamination, the
exact method to be used has not yet
been selected. However, project par-
ticipants continue to work toward the
goal of addressing the contamination
present at the former MGP site and fa-
cilitating the site’s return to productive
commercial use. CE
Carsten H. Floess, Ph.D., P.E., F.ASCE, is a
senior geotechnical engineer and Scott Underhill, P.E., a project manager in the Latham,
Outside the box. Inside the budget.
The Tunable Bridge™ has a patented, adjustable, dual-truss-and-tied-arch design that
can ‘tune’ live and dead loads between the two systems. Lighter weights. Longer spans.
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Prefabricated vehicular/pedestrian bridges
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6 ] Civil Engineering SEPTEMBER 2012 AIL-356 Outside the box. Inside the budget.
Civil Engineering – September, 2012
1/3 page square – 4.5625" × 4.875"
New York, office of AECOM, which has its
headquarters in Los Angeles. Tracy Blazicek,
CHMM, is a project manager for NYSEG, of
Binghamton, New York. Matthew Thorpe,
P.E., is a project engineer and Scott McDonough
and Reeti Doshi are environmental engineers
in the Latham, New York, office of AECOM.
This article is based on a paper the authors presented at GeoCongress 2012, which was held
in Oakland, California, in March under the
sponsorship of ASCE and its Geo-Institute.
PROJECT CREDITS Owner:
NYSEG, Binghamton, New York
Design engineering, construction management, and non-aqueous-phase
liquid recovery: AECOM, Los Angeles In situ solidification bench-scale
studies: KEMRON Environmental
Services, Inc., Vienna, Virginia In situ
solidification contractor: WRS
compass, Tampa, Florida Laboratory testing: Atlantic Testing Laboratories,
Ltd., Canton, New York