Environmental Engineering Reference
In-Depth Information
N
Former Fuel UST
Locations
Former Dry Cleaner Bldg
Floor Drain
Secondary DNAPL
Source Area
Former Dry Cleaner
Machine Location
Former
Wa
s
te Oil UST
Boiler Room
DNAPL Source Area
Ta r g e t Z o n e
Sump for Floor Drain
Drainage
Canal
0
20
40
60
80
Ft.
Figure 5.4
Sage's site map indicating former building and suspected contamination
areas.
found in the reports prepared for the Florida Department of Environmental
Protection by LFR Levine Fricke (1997a, 1997b, 1998, 2000).
5.3.2.3 Evaluation of preinjection natural attenuation potential
Initial evaluation of the Sage's site included an evaluation of natural atten-
uation. Groundwater parameter data from the existing wells were evaluated
for the potential for biodegradation based on scores for the natural attenu-
ation parameters developed according to the weighting guidelines provided
in Wiedemeier et al. (1996). The detailed results of this evaluation are
reported by LFR Levine Fricke (1997a, 1997b), in which the majority of the
wells (five of six) indicated inadequate to limited evidence for natural atten-
uation of chlorinated solvents (Table 5.1). Reductive dechlorination was
found not to be favored because of aerobic conditions, lack of sulfate reduc-
tion or methane production, and low levels of dechlorination products such
as chloride, ethene, and ethane. Based on this assessment, the conclusion
was that remediation by natural attenuation had limited potential as a sig-
nificant component of the overall remedial strategy for effective cleanup of
the site. It was also recognized that the DNAPLs present in the subsurface
would serve as continuing sources of chemicals that would contribute as a
long-term source to the dissolved groundwater plumes. The recommenda-
tion was to conduct the cosolvent flushing pilot test to study the effectiveness
of alcohol flooding for DNAPL remediation.
5.3.2.4 Well description
Three injection wells (IWs) surrounded by six recovery wells (RWs) were
used for implementation of the cosolvent flushing test and groundwater
monitoring. These wells were 10-cm-diameter polyvinyl choride (PVC) and
