SITE INFORMATION AND CORRESPONDENCE

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Phase I Environmental Site Assessment 8.0 FINDINGS 8.1 DISCUSSION Carlton's assessments,Site reconnaissance,agency review,and aerial photography review indicate the following. • No grading has been reported to have occurred on the Site. Past Site use has included limited structural development related to the existing power plant on the west,and farming or livestock grazing. • No groundwater production wells were observed or reported to exist on the Site. • One groundwater monitoring well was observed on the Site(part of the monitoring network for the adjoining WPCF). • Construction materials related to an improvement project at the adjoining WPCF are stored on the Site. • Two automotive batteries were observed in the construction materials storage area,and the batteries should be removed to an approved disposal or recycling facility. • No visible evidence of materials that would present an environmental impairment of the Site,such as soil staining and stressed vegetation,was observed during the Site reconnaissance(with the exception of oil-stained surface soil along the graveled drive path through the center of the Site. • Gray silty sediment suspected to remain from temporary stockpiling of WPCF pond lining and maintenance efforts was observed on the ground surface in the northern portion of the Site. • No evidence of underground or aboveground petroleum-product storage tanks was observed. Construction materials described in Section 6 of this report were observed on the Site during the Site visit. It is likely that prior to NCPA development of the Site,the materials will be removed by the City of Lodi for continued use in the WPCF improvement project. The automotive batteries should be removed from the Site and taken to appropriate disposal/recycling facilities. The presence of the oil-stained soil observed along the graveled drive path through the center of the Site is considered to fall within the category of"de minimis conditions"based on the limited area observed to be affected(additional areas could be covered by the gravel). De minimis conditions are defined in ASTM E 1527-05 as"conditions that generally do not present a threat to human health or the environment and that generally would not be the subject of an enforcement action if brought to the attention of appropriate governmental agencies". Should the oil staining be found to include a greater area than currently visible,additional characterization and possibly excavation and removal to an appropriate disposal facility could be warranted. Recent monitoring/analysis of samples from monitoring well WSM-2 located near the southeastern corner of the Site property indicates that:Nitrate as nitrogen was detected at a concentration above the California State Department of Health Services drinking water Maximum Contaminant Level,that dissolved iron and manganese were detected at concentrations above the Secondary Maximum Contaminant Levels/Consumer Acceptance Limits,that Total Dissolved Solids and Specific Conductance were detected in the upper Secondary Maximum Contaminant Level Ranges,and that Coliform bacteria was reported at>16 MPN/100 ml,in the shallow groundwater at the Site. None of the records reviewed during this assessment revealed recognized environmental conditions on the adjoining properties. Based on our reconnaissance of the Site and near vicinity,the hydrogeologic characteristics of the area,results of archival records and database searches and reviews,distances from the Site property to potential sources of contamination,and interviews with persons knowledgeable of the Site area,it is Carlton's opinion that contamination of the subject Site resulting from identified past activities on nearby properties is unlikely. Although unlikely,the possibility of contamination migrating to the Site from offsite sources and offsite practices must be recognized. Additional studies regarding off- site sources do not appear justified based on the data available to date. Lodi Energy Center Property ESA 13 Carlton Project No.6300-01-08 June 2008 CARLTON IM E n g i n e e r i n g I n c.