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I • SMr James Barton ' January 12, 2005 Page 3 ' Groundwater Sampling Analytical Results Groundwater samples collected from wells MW-31 and MW-32 were submitted to CLS for analysis of TPHg by EPA Method 8015 Modified, volatile organic compounds, EDB, and 1,2 DCA using EPA Method 8260B Additionally, groundwater parameters related to intrinsic biodegradation, specifically concentrations of nitrates and sulfates by EPA Method 300, iron (I1) ' by Standard Method 3500 Fe D, manganese (11) by EPA Method 200 7, and Methane by EPA Method RK were determined for samples from wells MW-31 and MW-32 Groundwater samples were collected using procedures described in Attachment D Concentrations of benzene, ' TPHg and MtBE were reported as not detected at or above the laboratory reporting limits In groundwater samples collected during this investigation Acetone was reported at 120ug/L in MW-32 Concentrations of chloroform were detected in MW-31 and MW-32 at 0 98 pg/L and ' 1 0 pg/L, respectively Groundwater sample analytical results are summarized In Table 2 and copies of the laboratory ' analytical reports are included In Attachment G Concentrations of TPHg, benzene, MtBE, and 1,2 DCA in groundwater are depicted on Figure 4 ' Waste Disposal Drilling activities generated approximately 5 cubic yards of soil cuttings The cuttings were ' placed In sixteen 55-gallon United Nations (UN)-approved drums and temporarily stored onsite Two composite samples were collected from the drums and submitted to CLS for analysis of TPHg, BTEX, MtBE, and 1,2 DCA using previously described methods Additionally, the samples were analyzed for total lead using EPA Method 60108 After receipt of laboratory results, sixteen drums containing soil drill cuttings were transported as non-hazardous waste on December 23, 2004 to Forward Landfill in Manteca, California ' Drilling activities generated approximately 50 gallons of decontamination water The water was placed in one 55-gallon UN-approved drum and temporarily stored onsite The decontamination water will be transported as non-hazardous waste to a Unocal approved waste facility during the first quarter of 2005 A copy of the laboratory analytical report is Included in Attachment E Copies of waste manifests are Included in Attachment H Well Survey IGroundwater monitoring wells MW-31 and MW-32 were surveyed by a California licensed land surveyor in accordance with State of California Assembly BIII AB2886 The top-of-casing elevation of the monitoring well and ground surface elevation were surveyed relative to mean sea level within 0 01 foot A copy of the survey is Included as Attachment • J LProiects10694015098 293Morkrng\ReportsM98 Well Installation Report doc ICelebrating 35 Years of Excellence in Eowonmental Sermrces