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S ECC> R
<br /> . Mr Jun Barton
<br /> February 23, 2006
<br /> ' Page 2
<br /> SECOR will prepare and submit quarterly groundwater monitoring report for
<br /> 1 Q2006
<br /> REPORT OF FINDINGS
<br /> On December 12, 2005, Gettler-Ryan Inc performed 4Q2005 groundwater monitoring and
<br /> sampling at the above-referenced site During this event, in addition to sampling routinely
<br /> scheduled monitoring wells, joint groundwater monitoring and sampling was conducted at
<br /> groundwater extraction wells by representatives of G-R and LFR During sampling, a
<br /> representative of SECOR was on-site to observe sampling protocol during collection of
<br /> duplicate groundwater samples from groundwater extraction wells on-site wells GEW-
<br /> 007A, GEW-008A, and GEW-022B, and off-site wells GEW-005A, GEW-006A, and GEW-
<br /> 023B Groundwater samples from the extraction wells collected by G-R were analyzed by a
<br /> suite of analytical methods chosen to assess the presence of total petroleum hydrocarbons
<br /> as gasoline (TPHg), diesel fuel, kerosene, mineral spirits, fuel oil, and coal tar oil, benzene,
<br /> toluene, ethylbenzene, and total xylenes (BTEX), methyl tertiary butyl ether (MtBE),
<br /> trichloroethene (TCE), and tetrachloroethene (PCE) Sampling was conducted in
<br /> accordance with G-R's Standard Operating Procedures (SOPs), a copy of which is provided
<br /> . along with G-R's Well Monitoring/Sampling Field Data Sheets (Attachment A) Included in
<br /> Attachment A are the Chain-of-Custody Documentation, Certified Analytical Reports for
<br /> groundwater monitoring well data, and gas chromatograms for TPH by GC-FID analyses
<br /> Groundwater monitoring well samples collected for the past three quarters have been
<br /> analyzed for BTEX, MtBE, di-isopropyl ether, (DIPE), ethyl tert-butyl ether (EtBE), tert-butyl
<br /> alcohol, (TBA), tert-amyl methyl ether, 1,1-Dimethylpropyl methyl ether (TAME), 1,2-
<br /> dichloroethane, (1-2, DCA), ethylene bromide (EDB), ethanol and methanol Whenever
<br /> possible, detection limits for all analyses, with the exception of methanol, ethanol, and TBA,
<br /> have been 0 5 ,ug/L Sporadically the detection limits were raised due to the presence of
<br /> elevated concentrations of PCE Typically detection limits for methanol, ethanol, and TBA
<br /> are 200 pg/L, 50 Ng/L, and 5 ug/L, respectively None of the fuel oxygenates have been
<br /> detected at or above the MDL during the past three sampling events Therefore, on
<br /> approval of the Regional Water Quality Control Board (RWQCB), SECOR discontinued
<br /> sampling and analysis for these analytes for the sampling event of 4Q2005
<br /> G-R's SOPs indicate that before sampling, each well is checked for the presence of
<br /> separate-phase petroleum hydrocarbons If separate-phase petroleum hydrocarbons are
<br /> not detected, then the depth to water and the total depth of each well is measured and
<br /> recorded before sampling If the well contains less than 1 5 feet of measurable water, then
<br /> the well is considered "dry" and is not sampled During the 4Q2005 monitoring event
<br /> several wells (MW-8, MW-9, MW-10, MW-12, MW-13, and MW-14) were not sampled due
<br /> to insufficient water After measuring the depth to water and total depth of all the wells,
<br /> 01 each well with sufficient water for sampling was purged of approximately three casing
<br /> volumes of water and sampled using a new disposable bailer Well screen intervals and
<br /> N 1Ft1es1ProjectslChevron4Retatll#9-61711Penodic M0ntt0nng1200514QMR14Q2005QMR doc
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