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Phase 1 ESA Update:Neighborhoods K&L,Mountain House,CA November 9,2011 Page 2 SUMMARY OF PHASE H ESA Condor completed a partial Phase II ESA as documented in the Limited Phase II Environmental Site Assessment Report, Proposed Neighborhoods D, K, L, and Town Center, Mountain House, San Joaquin County, California, dated November 30, 2004. The purpose of the partial Phase II ESA was to evaluate the recognized environmental condition of historical agricultural chemical use. In Neighborhood K, no pesticides or herbicides were detected in the soil samples collected from the agricultural fields. hi Neighborhood L, very low concentrations of the organochlorine pesticides DDE and DDT were detected. The concentrations were well below regulatory screening levels for unrestricted land use, and thus did not pose a risk to human health or the environment. CHANGES TO ENVIRONMENTAL DATABASES The environmental records source used for this update was the same as that used for the Phase I ESA. Environmental Data Resources (EDR) provided an EDR® Radius Map for the Site (Attachment B). The EDR Radius Map was reviewed including the orphan summaries.None of the locations listed in the EDR report appear to pose a risk to the Site, and several locations are past school site environmental investigations conducted by Condor under the oversight of the Department of Toxic Substances Control (DTSC). The California Regional Water Quality Control Board (RWQCB) and DTSC online databases were reviewed. Several investigations along Byron Road have been or are currently being conducted under RWQCB oversight related to the petroleum pipelines located there. Although the RWQCB has granted closure to several of these locations, the DTSC has not granted closure and is reviewing work conducted under RWQCB oversight. CHANGES TO SITE A driving reconnaissance of the surrounding area and a walking reconnaissance of the Site were perforined by Alex Dewitt in accordance with the ASTM practice on November 9, 2011 (Photographs, Attachment C). The Site was mass-graded and some underground utilities were installed in 2007 and 2008. Several monitoring wells were installed and monitored by Condor in both neighborhoods in the late 2000s for the purposes of monitoring groundwater quality during past land discharge of treated wastewater. The results of monitoring indicated no significant impact of groundwater related to the wastewater discharge. During the Site reconnaissance, several debris piles consisting mostly of native soil, concrete, and irrigation piping were observed on Neighborhood L. Large soil mounds resulting from grading operations were observed on both neighborhoods, and soil type was consistent with native soil. The wastewater detention ponds have not been in use for several years, and are planned to be removed in the future. OPINION AND CONCLUSIONS It is Condor's opinion that the only remaining recognized environmental condition for Neighborhoods K and L is the potential for petroleum hydrocarbons in soil and/or groundwater associated with the petroleum pipelines adjacent to the southern portion of Neighborhood L. There are no additional recognized environmental conditions relating to the Site. The monitoring wells are considered de minimis conditions. These wells should be properly abandoned/destroyed before development is completed. i CONDOR