SITE INFORMATION AND CORRESPONDENCE

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Blue Star - 3 - 25 October 2013 4040 E. Main St. Stockton, San Joaquin Country • The release consists only of petroleum. • The release has been stopped. The UST system was removed in March 2002. • Free product has been removed to the maximum extent practicable. Free product was not encountered. • A Site Conceptual Model has been developed. • The secondary source has been removed to the extent practicable. Secondary source was removed by excavation of approximately 200 tons of soil. The stockpiled soil was tested with maximum concentrations for total petroleum hydrocarbons as gasoline (TPHg), 13 milligrams per kilogram (mg/kg) and benzene, 0.023 mg/kg. Due to the proximity of the street to the open excavation and the low contaminant concentrations, the soil was approved for reuse as backfill in the excavation. Based on stable to decreasing concentrations in groundwater, GHD concluded that there does not appear to be a significant secondary source remaining that would reverse these trends. • Soil and groundwater have been tested for MTBE and the results reported in accordance with Health and Safety Code section 25296.15. Soil and groundwater have been tested for MTBE; MTBE was detected in two wells during the first quarter of 2013. Maximum MTBE in MW-1 was 11 ug/L. • A nuisance, as defined by Water Code section 13050 does not exist at the site. No nuisance exists from the release at this Site. 11)The Site meets the State Water Board's LTCP's Groundwater media specific criteria, scenario 1 as follows: • The contaminant plume that exceeds water quality objectives is stable or decreasing in areal extent. • GHD concluded that the Site meets all the requirements for scenario 1 of the groundwater criteria of the State Water Board's LTCP. The contaminant plume that exceeds water quality objectives (WQOs) is less than 100 feet in length. The TPH-G isoconcentration contour map and the first quarter 2013 groundwater elevation contour map are included as Figures 3 and 4. • There is no free product. • The closest water supply well or surface water body is greater than 250 feet from the defined plume boundary. The closest wells are approximately 600 feet northeast and 600 feet southeast of the Site. The municipal well 600 feet northeast was determined to be inactive and slated for destruction per California Water Service well destruction work plan submitted to SJCEHD and received by our office from CWS on 17 September 2013. The closest surface water was identified as Mormon Slough approximately 1,200 feet south of the Site. A well survey map is included as Figure 5.