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..d 30 May 2014 AGE Project No. 13-2557 Page 2 of 5 USTs) from the EHD. Additionally, an encroachment permit for excavation/backfill of the sidewalk was obtained from the City of Tracy Fire Department for removal of the tank. On 28 April 2014, AGE contracted to have the sidewalk concrete cut and prepared for excavation. Permits from the City of Tracy were obtained and the City inspector was contacted for the proposed scope of work. On 29 April 2014, AGE exposed the area of the previously identified potential UST at the edge of the site and determined the sidewalk covered the UST completely. AGE removed the sidewalk concrete. Initially, the soil over the UST was excavated from the site with a backhoe and stockpiled on-site. The UST was inspected to evaluate residual petroleum waste and was determined to be 75% full of liquids and semi-solids. The attempts to remove the semi-solids were not advantageous and the work was terminated until a high-vacuum waste truck and disposal service could be contracted. Upon the direction of the City of Tracy, the UST excavation was backfilled to surface grade with crushed rock and aggregate base (recycled class II road base). On 01 May 2014, the UST excavation was re-established and additional soil over the UST was removed and stockpiled. Advanced Chemical Transport (ACT) provided a heated pressure washer, vacuum truck and support services to evacuate the semi- solids from the UST. A black, oil-like residual with sediment and possibly waste fuels was present at the lower portion of the UST. Prior to removal of the UST, the tank was triple-rinsed by AGE, using a heated pressure washer and alconox solution. Approximately 300 gallons of waste and rinseate were transported under non-hazardous manifest to ACT Merced, California (Manifest Document No. D55935 under State Facility ID CAL000336454) by ACT of Merced, California (Attachment A). After rinsing, approximately 30 lbs. of dry ice then applied to the UST. The lower explosive limit (LEL) and free oxygen was simultaneously measured to evaluate the risk of fire prior to UST handling and removal. The tank and associated piping were removed, transported and properly disposed of by West Coast Equipment of Turlock, California. The tank disposal receipt and Tank Closure Form are included in Attachment B. Soil removed from the site was stockpiled at the site for future disposal. The remaining excavation cavity was backfilled and compacted with clean fill aggregate road base — class II. The road base engineered fill was compaction tested by the City of Tracy representative (Klinefelder). Concrete was imported and the sidewalk replaced and brought up to surface grade. Advanced GeoEnvironmenfal,Inc.