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Table 2 DPE Historic Groundwater Analytical Data—Total Petroleum hydrocarbons and BTEX South Shore Parcels-Parcel 2A and Adjacent Areas West Weber Avenue and North Lincoln Street Stockton,California Depth Ethyl- Sample (feet, Date TPHg TPHd TPHo Benzene Toluene benzene Xylenes MTBE TBA As ID b s Sam led m/1 m/I m /I m/I m/I (mg,,) m /I m g/,)/I m/I (mg/1) A Zone Wells-Area 2A/2B and Adjacent Areas(cont.) DPE-13 --- 2/9/07 Not sampled due to Sheen --- 5/7/07 Not sampled due to Sheen --- 7/3/07 Not sampled due to Sheen --- 10/8/07 Not sampled-well inaccessible --- 1/21/08 Not sampled due to Sheen --- 4/21/08 Not sampled due to Sheen --- 7/21/08 Not sampled due to Sheen --- 10/20/08 Not sampled due to SPH --- 1/19/09 Not sampled due to Sheen --- 4/20/09 Not sampled due to Sheen --- 7/27/09 Not sampled due to Sheen --- 10/19/09 Not sampled due to Sheen --- 1/18/10 Not sampled due to Sheen --- 4/19/10 Not sampled due to Sheen --- 7/19/10 Not sampled due to Sheen --- 10/18/10 Not sampled due to Sheen --- 1/24/11 Not sampled due to Sheen --- 4/18/11 Not sampled due to Sheen --- 7/18/11 Not sampled due to Sheen --- 10/17/11 Not sampled due to Sheen --- 1/17/12 Not sampled due to Sheen --- 4/16/12 Not sampled due to Sheen Explanations: TPHg=Total Petroleum Hydrocarbon,gasoline range TBA=Tert-Butyl Alcohol SPH=Separate Phase Hydrocarbons TPHd=Total Petroleum Hydrocarbon,diesel range As=Arsenic ---=Not Analyzed TPHo=Total Petroleum Hydrocarbon,oil range mg/I=milligrams per liter <=Below given laboratory detection limit MTBE=Methyl tert-butyl ether bgs=below ground surface J=The reported value is below the Method Reporting Limit should be considered an estimate. 2=Sample ID also known as W-21-MW2 by Mobile Chem Labs Inc.analytical data and Applied GeoSystems'Subsurface Environmental Investigation Report dated October 31,1989. 3=Sample ID also known as W-25-MW3 by Chemwest Analytical Labs Inc.analytical data&within Applied GeoSystems'Subsurface Environmental Investigation Report dated October 31,1989. 4=Sample exhibits fuel pattern that does not resemble standard. 5=Lighter hydrocarbons contributed to the quantitation. 6=Heavier hydrocarbons contributed to the quantitation. =Sample exhibits unknown single peak or peaks. s=QA/QC samples collected by Clayton Group Associates. 9=The method reporting limit for TPHd is increased due to interference from gasoline-range hydrocarbons. 10=Repeated analysis yielded inconsistent results. The highest recovery value of has been reported,but should be considered an estimate. "=Matrix Spike/Matrix Spike Duplicate Results for the analyte Benzene were affected by the analyte concentration already present in the un-spiked sample. 12=Samples collected by Clayton Group Services for Unocal:Lincoln/Weber. 13=The silica gel extract for TPHd contained a slight contamination from the material in the extract vial cap. These compounds were subtracted from the TPH value. 14 =Surrogate recovery for Method 8015 is above/outside the control limit(s). This may indicate a bias in the analysis due to the sample's matrix or an interference with the surrogate from compounds present in the sample. 15=The original silica-gel-treated extract for sample MW-11 yielded results that did not appear consistent with the non-silica-gel-treated extract. The sample was re-prepared and re- analyzed. The second analysis was more consistent,and is the one that has been reported. It was extracted out of hold time,however. 16=Hydrocarbons reported as TPH as Motor Oil do not exhibit a typical Motor Oil chromatographic pattern. These hydrocarbons are higher boiling than typical diesel fuel,and/or have discrete peaks which may or may not be petroleum related. Stantec 20120924-Parcel2A(Tables 4,5,6,7)Historical GW Tables 3Q12-CL.xlsx Page 6 of 7