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: .IF-5
<br />November 5, 2001
<br />53636.001
<br />Mr. Peter Ingram
<br />City of Redwood City
<br />Page 3
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<br />during EFW's September 1999 event4, the most recent data available to Harding ESE, were 176 ug/L,
<br />36.6 ug/L, and 104 ug/L, respectively, in well MW-12.
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<br />The former Greer/SPRR parcels were previously occupied by the Coast gasoline service station and the
<br />Glen Greer's Arco station. Today the parcel is occupied by Blockbuster Video and a small parldng lot.
<br />The highest concentrations ofPCE, TCE, and cis-DCE detected by EFW during its September 1999
<br />monitoring event were 550 ug/L, 66 ug/L, and 156 ug/L, respectively, in well E-11.
<br />
<br />Roy's Cleaners
<br />
<br />In May 1995, Applied Science and Engineering, Inc. (ASE) performed a groundwater investigation at
<br />Roy's Cleaners5. During the investigation, monitoring well MW-1 was constructed to a depth of 16.5
<br />feet bgs in close proximity to a sanitary sewer lateral in front of the facility, which connects to the City's
<br />sanitary sewer line along ECR. Analyses performed on soil samples collected from the well boring
<br />detected no HVOCs. Concentrations of PCE and TCE were detected in a groundwater sample at 77
<br />ug/L and 11 ug/L, respectively.
<br />
<br />Sanitary Sewer Investigations
<br />
<br />The potential sources of HVOCs in groundwater beneath the former Davies parcel have been the subject
<br />of numerous discussions and correspondences between the City, SFRWQCB staff, and Safeway since
<br />1996. In 1996, the SFRWQCB required the City to perform a video survey of the sanitary sewer line
<br />beneath ECR from James Avenue to Jefferson Avenue. Results of a sewer video survey~ conducted by
<br />the City revealed several side and top cracks, in addition to two broken segments: one at approximately
<br />218 feet southeast of Manhole MH01A. Results of the sewer video survey alone, however, did not
<br />demonstrate whether HVOCs were released from the sanitary sewer.
<br />
<br /> groundwater investigation along a 150~foot segment of the
<br />In February 2000, SCI conducted a soil and 7
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<br />sanitary sewer beneath ECR between Jefferson and Harrison Avenues, upgradient of the former Davies
<br />parcel. Results of the investigation indicated the presence of PCE, TCE, and cis-DCE concentrations up
<br />to 60,000 ug/L, 79 ug/L, and 270 ug/L, respectively, in groundwater samples collected along the
<br />downgradient (east) side of the sanitary sewer. In comparison, analyses detected concentrations of PCE,
<br />TCE, and cis-DCE up to 45 ug/L, 5.1 ug/L, and 5 ug/L, respectively, in groundwater samples collected
<br />along the upgradient (west)side of the sanitary sewer. SCI indicated in their report that available
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<br />4 Conor Pacific/EFW, Third Quarter 1999 Groundwater Monitoring Report, Sequoia Station Retail Center,
<br />November, 1999.
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<br />s Applied Science and Engineering, Inc., Groundwater Investigation Report. Roy's D~7 Cleaners, 1 lO0 E1 Camino
<br />Real, July 1995.
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<br />6 Kennedy/Jenks Consultants, Sequoia Station A rea Sewers, February 1998.
<br />
<br />? Subsurface Consultants, Inc., Soil and Groundwater Investigation Along Sanitat7 Sewer, Vicinity offormer
<br />D?tvies Parcel, July 2000.
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<br /> Harding ESE
<br /> A MACTEC
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