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fl � Canepa's Car Wash 6230 Pdeli]C Avenue,Stockton,CA First Quarter Groundwater Monitonng Report,January 2005 Page 2 of 8 • Table 1 Summary of January 2005 Quarterly Groundwater Monitoring Results Field Activit Number of groundwater momtormg 11 Number of groundwater monitoring 7 wells (does not include soil vapor wells sampled extraction well SV-4 Number of groundwater monitoring 11 Date(s)monitored and sampled 1/21/2005 wells measured for water level Site Hydrology Average depth to groundwater below 38 99 feet Average increase (+)/decrease(—) in - 164 feet shallow monitoring well measuring (excluding depths to groundwater since last (shallower) points MW-1) sampling(excluding MW-1 Approximate flow direction and Cone of Drawdown=6 feet groundwater gradient depression Radius of influence=25 feet toward MW-1 Groundwater Contamination Monitoring wells containing free None* Monitoring wells with petroleum 3 product(does not include SV-4) hydrocarbon odor noted(does not include SV-4 Number of monitoring wells with 3 Number of monitoring wells with 4 concentrations below both the benzene concentrations at or above either or and MTBE MCLS both the benzene and MTBE MCLs Nature of contamination BTEX, Range of analyte concentrations TPH-G, detected in the monitoring wells Gasoline Benzene (µg/L) <0 5—8,400 Oxygenates Toluene(µg/L) <0 5—3,800 /Additives Ethyl Benzene(pg/L) <0 5—2,500 Total Xylenes(pg/L) <1 5—4,370 TPH-G(mg/L) <0 05—37 MTBE(pg/L) <0 5—7,200 1,2-DCA(pg/L) <0 5—82 TAME (gg/L) <0 5—<1 0 *Note A sheen was noted in the purge water from MW-2 FIELD OBSERVATIONS A Condor representative made field observations on January 21 and 24, 2005 at the 11 site monitoring wells (MW-1 through MW-7, and MW-9 through MW-12D) and at one soil vapor extraction well (SV-4) Depth to groundwater measurements were collected from MW-1 through MW-7, MW-9 through MW- 12D, and SV-4 (see Table 2 on the following page) MW-1 and MW-11 are used for groundwater extraction related to the operation of the groundwater treatment system Field observations included appearance of samples (color, clarity, and presence of petroleum product sheen or phase in samples), collection of water quality field parameters and anv other conditions of note Field obser<�ati�ns are included in the field forms (Attachment E) No sheen or separate phase petroleum was noted in bailed field inspection samples from any of the site monitoring wells and SV4, however, a sheen was noted in the purge water bucket after purging MW-2 and SV-4 A moderate petroleum odor wds noted in MW-2 and SV-4 A slight odor was noted in monitoring wells MW-1 and MW-11 �� CONDOR