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• Second Semiannual and 2018 Annual Groundwater Monitoring Report J�COBS®
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<br /> 1.2.3.1 Three-Year Bioremediation Pilot Study and Monitored Natural Attenuation
<br /> • The 3-year bioremediation pilot test was implemented from 2004 to 2007 in accordance with the
<br /> bioremediation pilot study work plan (CH2M, 2003). The 3-year final evaluation report for the pilot study
<br /> concluded that natural processes were sufficient to contain the hydrocarbon plume and maintain the
<br /> stable-to-decreasing trend in hydrocarbon concentrations in groundwater. The pilot study also concluded
<br /> that monitored natural attenuation (MNA) is effective at the site (CH2M, 2007a). The RWQCB agreed with
<br /> •, the conclusions that MNA is occurring in a letter to SFPP dated November 14, 2007. The hydrocarbon
<br /> plume and groundwater concentrations are monitored under current MRP No. R5-2018-0806 to document
<br /> that the hydrocarbon plume and groundwater concentrations are stable and decreasing under MNA
<br /> . conditions. SFPP removed the GWETS after the initial year of the pilot study, and in a letter dated
<br /> July 7, 2005, the RWQCB rescinded the NPDES permit under which the GWETS operated. SFPP
<br /> • removed the aboveground portions of the groundwater treatment system in October 2005. Trees were
<br /> planted in the footprint of the former groundwater treatment system as part of the phytoremediation
<br /> system.
<br /> 1.2.3.2 Phytoremediation System
<br /> Phytoremediation is being implemented as the final remedial measure in the source area in accordance
<br /> with the Cleanup Plan Using Phytoremediation for the Source Area (CH2M, 2004). Construction of the
<br /> phytoremediation system was conducted in two phases:
<br /> • Phase 1 (Areas A, AA, and B)was constructed in January/February 2005.
<br /> ! 0 Phase 2 (Areas C and D)was constructed in March/April 2006.
<br /> Construction of Phases 1 and 2 is documented in two respective as-built reports (CH2M, 2005, 2007b).
<br /> • 1.2.4 Monitoring and Reporting Program
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<br /> A total of three MRPs have been issued at this site. The first MRP, No. R5-2004-0803, was issued on
<br /> January 30, 2004, by the RWQCB. In addition to monitoring general groundwater conditions, this MRP
<br /> was developed specifically to monitor the bioremediation pilot test, as described in the bioremediation
<br /> pilot study work plan (CH2M, 2003). The MRP required detailed quarterly groundwater monitoring,
<br /> semiannual reports for the first semiannual period (fourth quarter 2006 and first quarter 2007) and for the
<br /> second semiannual period (second and third quarters 2007), in addition to semiannual electronic data
<br /> • reports submitted for the second and fourth quarters.
<br /> The second MRP, No. R5-2007-0831, was issued on November 29, 2007, by the RWQCB. This MRP
<br /> was developed to monitor site conditions with MNA and phytoremediation as remedies. This MRP
<br /> eliminated most of the parameters added in the previous MRP to monitor the bioremediation pilot test,
<br /> eliminated unnecessary monitoring wells and parameters, allowed for the destruction of unnecessary
<br /> . monitoring wells, and allowed for the destruction of the SVE well system.
<br /> The third and current MRP, No. R5-2018-0806, was issued on March 21, 2018, by the RWQCB to
<br /> continue to monitor current site conditions with MNA and phytoremediation as remedies. This MRP
<br /> requires semiannual gauging of select wells (N-7, N-16, N-17, 0-1, RW-1, M-10, N-8, N-15, N-18, N-24)
<br /> • during the first and third quarters of each year. In addition, it also requires semiannual sampling of wells
<br /> N-7, N-16, N-17, 0-1 and RW-1 during the first and third quarters and annual sampling of wells M-10,
<br /> N-8, N-15, N-18, and N-24 during the first quarter only. All reports must be submitted electronically to the
<br /> State Water Resources Control Board's GeoTracker database on a semiannual basis (May 1 and
<br /> November 1). An annual report is due by November 1 of each year and may be substituted for the second
<br /> i semiannual report.
<br /> • AX1015181035SCO
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