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<br /> A C February 12, 2020
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<br /> pounds of TPHg and BTEX. When calculated using an average density of gasoline of 6.25 pounds
<br /> per gallon, the amount of hydrocarbons extracted is represented by approximately the equivalent of
<br /> 2,641 gallons of gasoline.
<br /> Between April 21 and April 25, 2008, ATC advanced five Cone Penetrometer Test (CPT) borings
<br /> (CPT4 through CPT8) at the site. CPT4 through CPT7 were advanced to a depth of 130 feet bgs,
<br /> while CPT8 was advanced only to 117 feet bgs due to probe refusal. Groundwater samples were
<br /> collected at various depths using a Hydropunch sampler. On May 20, 2008, ATC advanced an off-
<br /> site CPT boring, CPT9, to a depth of 121.5 feet bgs, and collected groundwater samples from this
<br /> location. The results of this investigation were summarized in ATC's Subsurface Investigation Report,
<br /> Former Greer Property, dated August 13, 2008.
<br /> In response to a request contained in correspondence from the SJCEHD dated August 27, 2008,
<br /> ATC prepared a workplan titled, Workplan to Conduct Verification Soil Sampling, Ozone Bench
<br /> Testing, and Vertical Groundwater Evaluation, dated October 24, 2008. The tasks described in this
<br /> workplan included collection of soil samples near the former UST system to evaluate the SVE system
<br /> effectiveness, collection of appropriate soil and groundwater samples for an ozone bench scale test,
<br /> and the performance of the ozone bench scale testing to evaluate the efficacy of ozone as a site
<br /> remediation technology. It also included provisions to install a deep groundwater monitoring well in
<br /> an attempt to define the vertical extent of dissolved-phase contaminants. The SJCEHD approved the
<br /> October 24, 2008, work plan in correspondence dated November 13, 2008.
<br /> A domestic well exists on the adjacent property immediately north of the site. The property changed
<br /> ownership and in the beginning of June 2009, ATC drafted and sent a site access agreement to the
<br /> new owner, however the owner initially denied ATC's request for access. In correspondence
<br /> addressed to the owner from the SJCEHD dated July 15, 2009, the SJCEHD requested he
<br /> reconsider his decision but no response had been received. Consequently, no gauging or sampling
<br /> of the domestic well, PDW, took place at that time.
<br /> On May 19, 2009, the California State Water Resources Control Board passed Resolution No 2009-
<br /> 0042. This resolution requires reduction from quarterly groundwater monitoring to semi-annual or
<br /> less frequent monitoring at all sites, unless site-specific needs warrant otherwise. In a letter dated
<br /> July 14, 2009, the SJCEHD directed a reduction in the sampling of any monitoring wells currently on
<br /> a quarterly sampling schedule to a semi-annual schedule. Consequently, sampling events typically
<br /> occurred in the second and fourth quarters of the year.
<br /> On July 13 and 14, 2009, ATC advanced soil borings SB1 and SB2 to collect soil samples for
<br /> verification soil sampling of on-site vapor extraction. In addition, from July 20 to 28, 2009, a deep
<br /> monitoring well (MW11) was installed through conductor casing, and soil samples were collected for
<br /> ozone bench scale testing. On July 21, 2009, MW2 was purged and a groundwater sample was
<br /> collected and submitted for the ozone bench scale testing. MW11 was developed on July 31, 2009,
<br /> and again on August 6, 2009. At the direction of the SJCEHD, MW11 and the Domestic Well (DW)
<br /> were to be sampled for four consecutive quarters, after which time the sampling interval was to be
<br /> re-evaluated. The initial sampling of MW11 and DW occurred on August 25, 2009.
<br /> ATC submitted the Well Installation and Verification Testing Report, dated January 12, 2010, that
<br /> documented the advancement of SB-1 and SB-2 and the installation of MW-11 in July 2009. SB-1
<br /> and SB-2 were advanced to determine the effectiveness of the SVE system. Since no hydrocarbons
<br /> were detected by laboratory analyses of the collected soil samples, ATC recommended making the
<br /> temporary cessation of the operation of the SVE system permanent and to remove the SVE system.
<br /> ATC also reported on the installation of MW11, the intent of which was to provide vertical definition
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