7301 EVERGREEN WAY EVERETT CHEVROLET 2017-03-01

One confirmatory soil sample will be collected from each sidewall of the excavation. Soil samples will be selected for laboratory analysis based on the highest PID reading or area exhibiting visual or olfactory evidence of impact. The purpose of this area excavation is to remove soil exceeding the MTCA Method A Cleanup Levels for protection of groundwater as a drinking water resource. 4.3.3 Parts Warehouse (Building 2) Excavations HL-2-5 West: Based on the soil analytical data, EEC anticipates the approximate extent of excavation will be 18 ft by 18 ft, and 6 ft deep; a total of approximately 72 cy. Confirmatory soil samples will be collected once the anticipated excavation vertical and lateral extents are achieved. A minimum of five confirmatory soil samples will be collected from the excavation. One confirmatory soil sample will be collected from the base of the excavation at approximately 6 ft bgs. One confirmatory soil sample will be collected from each sidewall of the excavation. Soil samples will be selected for laboratory analysis based on the highest PID reading or area exhibiting visual or olfactory evidence of impact. The purpose of this area excavation is to remove soil exceeding the MTCA Method A Cleanup Levels for protection of groundwater as a drinking water resource. HL-1-6 West: Based on the soil analytical data, EEC anticipates the approximate extent of excavation will be 12 ft by 14 ft, and 6 ft deep; a total of approximately 37 cy. Confirmatory soil samples will be collected once the anticipated excavation vertical and lateral extents are achieved. A minimum of five confirmatory soil samples will be collected from the excavation. One confirmatory soil sample will be collected from the base of the excavation at approximately 6 ft bgs. One confirmatory sample will be collected from each sidewall of the excavation. Soil samples will be selected for laboratory analysis based on the highest PID reading or area exhibiting visual or olfactory evidence of impact. The purpose of this area excavation is to remove soil exceeding the MTCA Method A Cleanup Levels for protection of groundwater as a drinking water resource. All confirmation soil samples will be analyzed for TPHo using Method NWTPH-Dx in conjunction with the silica gel method. The confirmation soil samples will be submitted to an accredited laboratory with an expedited, three-day turn-around-time (TAT). The excavations will not be backfilled until analytical results are reviewed by EEC. 4.3.4 Backfilling Upon completion of satisfactory confirmation sampling, the excavations will be backfilled with clean imported fill material and/or clean soil removed during excavation activities. "Clean" will be defined as meeting the Ecology regulatory definition of clean backfill materials. Soils previously segregated during excavation activities due to the absence of elevated PID readings and visual or olfactory evidence of impact will be sampled prior to use as backfill material in accordance with Ecology regulations. The source and type of the clean imported fill material will be reviewed and approved by AHLLC prior to backfilling. The future use of the Site will affect the type of fill material selected (e.g. structural fill). All existing open excavations are to be appropriately barricaded and fenced. All areas shall be maintained using temporary erosion and sediment control measures in accordance with local industry practices and requirements. Backfill material is to be compacted using no more than 8 inch lifts. It will be the responsibility of the contractor to select a compaction method that is an approved industry method compatible with the selected backfill material. 017386-174(123) 8 THIS DOCUMENT IS PRINTED ON RECYCLED PAPER Encore Environmental Consortium,LLC