|
%T C
<br /> A S S O C I A T E S I N C
<br /> L samples were collected from the borings. On July 21, 1995, Smith Technology developed and
<br /> sampled monitoring wells MW-1, MW-2, and MW-3. Analytical results of the soil samples
<br /> collected delineated the vertical extent of petroleum hydrocarbon contamination of the vicinity of
<br /> the former gasoline UST locations. Soil and Groundwater analytical results are summarized in
<br /> Tables 1 and 2, respectively. This phase of work was detailed in Smith Technology Corporation's
<br /> Problem Assessment Report, Fayette Manufacturing Corporation, 7675 West Eleventh Street,
<br /> Tracy, California, dated November 7, 1995.
<br /> On September 24 and October 2, 1996, Smith Technology supervised the advancement of nine
<br /> tAW additional soil borings, SB-1 through SB-7 and FPB-1 and FPB-2 at the locations shown on
<br /> Figure 2. Soil boring logs are contained in Appendix A. The borings were advanced utilizing
<br /> direct push technology and soil, soil vapor, and groundwater samples were collected for chemical
<br /> analyses. Analytical results of the soil, soil vapor, and groundwater samples collected delineated
<br /> the horizontal extent of petroleum hydrocarbon contamination in the vicinity of the former
<br /> gasoline UST locations. Analytical results for chemical analyses are summarized in Tables 1, 2,
<br /> and 3.
<br /> During this phase of work, the collected soil, grab groundwater, and soil vapor samples were also
<br /> r submitted for geophysical analysis to determine if natural biodegradation of petroleum
<br /> constituents was occurring beneath the site. Soil samples from significantly different lithological
<br /> units encountered during drilling were submitted for the following geophysical analyses: falling
<br /> head permeability, percent moisture, porosity, dry bulk density, soil pH, percent organic content,
<br /> and carbon to nitrogen to phosphorus (C:N:P) ratios. Grab groundwater samples were field
<br /> monitored for oxidation-reduction potential and submitted for laboratory analysis of carbon
<br /> dioxide, alkalinity, nitrate, sulfate, and ferrous iron. Soil vapor samples were submitted for
<br /> laboratory analysis of oxygen, carbon dioxide, nitrogen, and methane. Analytical results of
<br /> geophysical analysis are summarized in Tables 1, 2, and 3. This phase of work was detailed in
<br /> Smith Technology Corporation's Additional Soil and Groundwater Report, Fayette
<br /> Manufacturing Corporation, 7675 West Eleventh Street, Tracy, California, dated January 31,
<br /> 1997.
<br /> Based on the results of previous site investigations, ATC prepared a technical report that
<br /> �~ considered three remedial alternatives for soil and groundwater at the site. Soil and groundwater
<br /> remedial alternatives that were evaluated included natural attenuation with groundwater
<br /> AM monitoring; excavation of remaining petroleum impacted soil; and in-situ vapor extraction with air
<br /> sparging. Natural attenuation of the petroleum hydrocarbons beneath the site was selected as the
<br /> preferred remedial choice. A more detailed discussion of the remedial alternatives was included in
<br /> ATC's Problem Assessment Report & Corrective Action Plan for 7675 West Eleventh Street,
<br /> Tracy, California, dated April 1, 1998.
<br /> Between September 1996 and June 1997, groundwater samples collected from each of the site's
<br /> monitoring wells were analyzed for specific geochemical parameters to assess intrinsic
<br /> wA95122Veports\Request for NFA.&c 2
<br /> r
<br />
|