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aquifer at a depth of about 13 feet below grade and appeared to be unconfined at the time of <br /> drilling. <br /> Groundwater measurements collected on October 22, 2009 from well MWWES-1 and the <br /> existing CH2M Hill wells. An initial plot indicates a northwest groundwater flow direction at a <br /> gradient of about 0.0007 at the new well vicinity. A small groundwater mound might be present <br /> in the vicinity of MWWES-1 located near two impoundments. The amount of seepage from the <br /> impoundments and its possible effect on local groundwater levels are not known. <br /> Table 1.Monitoring Well Groundwater Measurement Data <br /> Monitoring Date of Well Well Depth to Top of Well Groundwater Comments <br /> Well Water Level Depth Diameter Ground Casing Elevation <br /> Number Measurement 00 (inches) Water in feet Elevation in in feet <br /> feet <br /> MWWES-1 10/22/09 24.49 2 8.97 19.34 10.37 None <br /> MMP-5# 10/22/09 40.88 4 15.48 25.97 10.49 None <br /> MWHP-6# 10/22/09 36.51 4 12.17 20.95 8.78 None <br /> MWHP-7# ]0/22/09 32.15 4 9.79 18.31 8.52 None <br /> MWHP-8# 10/22/09 26.40 4 10.10 19.07 8.97 No <br /> # -Existing C112M Hill Monitoring Well Number. Well Casing elevation to NGVD in feet surveyed by City of <br /> Tracy. <br /> 6.0 Groundwater Chemical Analysis and Discussion <br /> One (1) groundwater sample was analyzed at Kiff Analytical LLC, a State-certified analytical <br /> laboratory in Davis, California. The sample was tested for the following: Total Petroleum <br /> hydrocarbons as Gasoline(TPHG) and Diesel (TPHD), Benzene(B), Toluene(T),Ethylbenzene <br /> (E), Xylene (X) using EPA Methods 3510/8015, 8020 and 8260/8260B. The analyses was <br /> performed and a"normal"ten-day turnaround. The results are presented in Table 2 below and <br /> the analytical reports are attached. <br /> The chemical analysis showed that TPHD was detected in MWWES-1 at 51 micrograms per liter <br /> (Ug/L). TPHG and BTEX were not detected in the water sample. <br /> The previous Wright study conducted in 2008 (borings B-6 through B-9) showed groundwater <br /> samples with TPHD in B-5 at 490 micrograms per liter (Ug/L) and B-7 at 300 Ug/L. B-6, B-8 <br /> and B-9 were all 200 Ug/l or less(see Table 2). The laboratory noted that the hydrocarbons were <br /> higher boiling than typical Diesel Fuel in all the 2008 samples. The Wright 2003 study showed <br /> that analysis of soil and groundwater samples had not revealed the presence of any TPHG, <br /> BTEX,MTBE or related oxygenates. <br /> Page 5 of 9 <br />