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0L,,29 93 09:48 _%2916 366 7013 aA, KKffiLviu 40`+I+ require an excavation and grading permit, the bum pit area and the teepee area now warrant a remedial work plan and the teepee area is adjacent to the trench, it seems prudent to include the trench work in a common remedial work plan with the other sites. I $cooe of Work Task 1: Work Flan and Permitting Kleinfelder will prepare a remedial work plan addressing the removal of impacted soil, removal verification soil sampling, stockpile , sampling, and potential avenues for the disposition of impacted soil depending on the results of the stockpile samples. In addition, Kleinfelder will prepare ;he applications for environmental work plan review and excavation and grading permit. The: applications will be submitted to AMM for the required signatures and submittal to the County. Task 2: Soil Excavation Task 2A: Burn Pit Area Based on the limited assessment, Kleinfelder will assume for estimating purposes that an approximately 400 square foot area to a depth of approximately 15 feet will need to be excavated. This estimate is based on the limited vertical migration indicated by the three samples from bolting B-2 and the assumption that lateral migration beyond the burn pit has not occurred. The data from B-2 indicates that the top 7 feet (approximately 150 cubic yards) may not be impacted and shoald therefore be stockpiled and sampled separately from the bottom 8 feet (approximattly 175 cubic yards). Upon excavation, the soil will be placed directly in bins provided by AMM. Whim each bin is full, the AMM supplied and operated forklift will be used to deposit the soil in the proper stockpile. Based on the potential depth (15 feet), the quantity of soil to be moved (approximately 325 cubic yards), and the unconsolidated soil around the burn pit, Kleinfelder recommends excavating the soil with an excavator (verses a backhoe). The excavator has a longer reach which will allow it to be further from the excavation and still reach the anticipated depth. This should reduce the potential for the unconsolidated sediments to lose lateral support. In addition, the larger bucket should increase productivity. Although the excavator costs approximately 40 percent more than the backhoe on a per yard basis, site !Fafety and increased productivity should reduce the impact to the total project cost. Task 211: Trench Area While on site for the bum pit area remediation, soil potentially impacted by petroleum hydrocarbons at the drainage ditch (trench) will be removed. Based on the assumptions that the trench is approximately 15 feet wide and approximately 75 feet long, and that only 1 foot of soil will need to be removed from the trench, approximately 60 cubic yards of soil will be excavated. In addition, adjacent to the drain, approximately I cubic yard of material will be removed. The soil from ;he drain and trench will be stockpiled at the teepee area. Task 2C: Teepee Area Upon removal of the trench area stockpile from the teepee area, an additional approximately 6 inches of soil/debris will be removed. Assuming a 20 foot radius, approximately 6 cubic yards of material will be added to the soil being disposed. FHB-92-222 Page 2 of 7 24 220182-800 C,,r At 4992 Kleinfelder, hie,