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stantec
<br /> L & M OPERABLE UNIT-THIRD QUARTER 2010 SITE STATUS, REMEDIAL SUMMARY,
<br /> AND GROUNDWATER MONITORING REPORT
<br /> October 27, 2010
<br /> 2.0 Groundwater Monitoring and Sampling
<br /> 1
<br /> 2.1 GROUNDWATER MONITORING AND SAMPLING PROCEDURES
<br /> ' Quarterly groundwater sampling of 14 shallow wells (A-Zone) (MW-9, 2AMW-12, MW-18,
<br /> MW-20 through MW-23, MW-25, MW-28, MW-30, MW-31, MW-33, MW-34, and MW-45), 15
<br /> ' B-Zone wells (MW-16, MW-24, MW-26, MW-27, MW-29, MW-32, MW-35, MW-42, MW-44,
<br /> MW-51, and MW-56 through MW-60), eight C-Zone wells (MW-54, and MW-61 through
<br /> MW-67), and eight D-Zone wells (MW-55, and MW-68 through MW-74), were performed by
<br /> ' Stantec between July 19 and July 22, 2010. Groundwater monitoring and sampling activities
<br /> were performed as required by MRP No. R5-2004-0820 (Appendix A), which was issued by the
<br /> RWQCB on May 6, 2004. MRP No. R5-2004-0820 is summarized in Table 1.
<br /> ' On behalf of the RDA, Wallace-Kuhl is responsible for monitoring and sampling at the portion of
<br /> the South Shore Parcels identified as the MOU and the UOU. Five shallow wells, MW-3,
<br /> ' MW-7, 2AMW-15, MW-37, and MW-38 are located in the MOU and UOU and are gauged and
<br /> sampled by Wallace-Kuhl. Stantec's groundwater monitoring and sampling activities are usually
<br /> conducted concurrently with Wallace-Kuhl, however during the third quarter 2010 Wallace-Kuhl
<br /> ' gauged wells for depth to water, but did not sample any wells. Wells MW-36 and 3MW-1 R,
<br /> which were previously part of the MOU/UOU MRP, were destroyed by Clayton on April 5, 2004
<br /> due to the development of the adjacent parcel. Well MW-6 was destroyed by Golden State
<br /> Environmental on June 21, 2007 due to excavation and construction activities in the area;
<br /> MW-06R was reinstalled in close proximity in November 2008. Wells MW-4, MW-5, MW-8,
<br /> MW-10, MW-11, MW-40, MW-53, and MW-39 were abandoned by the RDA's consultant T&R
<br /> ' during 4Q08. Wells 2BMW-1 and MW-06R were abandoned by the RDA's consultant
<br /> Wallace-Kuhl during 2Q10 and 3Q10, respectively.
<br /> ' Groundwater monitoring wells were sampled according to the requirements stated in MRP
<br /> No. R5-2004-0820, with the exception of the following:
<br /> • Shallow wells MW-1 and MW-2 have not been sampled since September 1999 and July
<br /> 1990, respectively. There is no evidence that these wells still exist, and therefore, these
<br /> wells are considered lost.
<br /> ' • Wells MW-4, MW-5, MW-6, MW-8, MW-10, MW-11, MW-36, MW-39, MW-40, MW-41,
<br /> MW-53, and 3MW1-R were previously destroyed due to Unocal excavation activities.
<br /> MW-6 was reinstalled as MW-06R; however, MW-06R was subsequently abandoned by
<br /> RDA's consultant Wallace-Kuhl during 3Q10 due to redevelopment activities on the
<br /> MOU.
<br /> • Well 2BMW-1 was abandoned during the second quarter 2010.
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