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California�ional Water Quality Con* Board <br /> ( \- Central Valley Region ' a <br /> v .' <br /> Karl E.Longley,SeD,P.E.,Chair 4 ^ <br /> Linda S.Adams 11020 Sun Center Drive#200,Rancho Cordova,California 956706114 Arnold <br /> nv ronm for Phone(916)464-3291 •FAX(916)464-4645 Sehwarzenegger <br /> Environmental http://www.waterboards.ca.gov/centralval ley Governor <br /> Protection r <br /> Uv� 'Jl�!-kVED <br /> 27 August 2008 <br /> Ms. Eugenia Valdez til'; � 9 LROB <br /> J«L Market ENV;n'u 01.1 T HEALTH <br /> 8125 EI Dorado Street PERfAT/SERVICES <br /> French Camp, CA 95231 <br /> DOCUMENT REVIEWS, J&L MARKET, 81?'5 S. EL DORADO ST., FRENCH CAMP, <br /> SAN JOAQUIN COUNTY <br /> I reviewed the Monitoring Report First Quarter 2008 (1 Q2008), the Monitoring Report Second <br /> Quarter 2008 (2Q2008) and the Revised Subsurface Investigation Workplan (Workplan) <br /> submitted electronically to GeoTracker on 25 July 2008, 29 July 2008 and 28 August 2008 <br /> respectively by your consultant ATC Associates, Inc. (ATC). <br /> The 1Q2008 and 2Q2008 data show increasing maximum concentration trends for Total <br /> Petroleum Hydrocarbons as diesel (TPHd); 2,000 to 2,500 micrograms per Liter, or ug/L; TPH <br /> as gasoline (TPHg), 830 to 3,400 ug/L; benzene; 38 to 500 ug/L; toluene, 0.54 to 6.9 ug/L; <br /> ethylbenzene, 49 to 560 ug/L; xylenes, 6.8 to 49 ug/L; and methyl tert butyl ether (MTBE), 8.7 to <br /> 11 ug/L. The maximum concentration for 1,2-dichloroethane (1,2-DCA) decreased from 230 to <br /> 160 ug/L. The groundwater monitoring results are consistent with the previous two years data, <br /> which show variations in concentrations that are not consistent with seasonal groundwater <br /> fluctuations. The lateral extent of the groundwater plume appears to be defined by the existing <br /> shallow monitoring wells; however, the vertical extent of the groundwater plume is undefined. <br /> Groundwater flow direction varied from northeast (1Q2008) to circularly inwards towards <br /> monitoring well JLM-3 (2Q2008). <br /> The Workplan, submitted in response to my 5 December 2007 directive letter, proposes <br /> installation of seven monitoring wells (enclosed Figure 2) to provide vertical definition of the <br /> groundwater plume. One cross section location map and three cross sections were included to <br /> show the new wells and lithology. <br /> Comments: <br /> 1) The Workplan is approved with the following conditions. <br /> 2) The proposed wells shall be installed without further delays and sampled quarterly, starting <br /> with the fourth quarter 2008 (402008) monitoring event. Extensions will not be approved. <br /> 3) Six of the proposed monitoring wells are adequate and necessary for monitoring the <br /> intermediate (70' below ground surface or bgs) and mid-deep (90' bgs) permeable sand <br /> zones. <br /> California Environmental Protection Agency <br /> (a Recycled Paper <br />