ARCHIVED REPORTS XR0001587 - Laserfiche WebLink

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• shown on Plate 2 . The area shown is the maximum extent of excavation recommended. However, the actual excavation size should be determined by field observations as to the presence or absence of hydrocarbons in the soil, and field observations regarding the safety of continued excavation until the maximum area has been excavated. Continued excavation should be limited to that which is determined by the excavation contractor in the field to be safe. However, under no circumstances should excavation be continued beyond the area designated in Plate 2 without additional concurrence from a registered geotechnical engineer and West Clay Properties. During excavation, the soil will be field screened with an organic vapor monitor (PID or FID) . The vertical extent of the excavation should be limited by the vertical extent of hydrocarbons, as determined by organic vapor monitor screening, and field observations or 45 feet below existing grade, whichever is less. Once the excavation is complete, confirmation samples will be obtained from the north and east sidewalls and the excavation bottom at the sampling frequency specified by the SJCEHD. For estimating purposes, include five sidewall samples and four bottom samples. All samples will be obtained by pushing a sample sleeve into the soil obtained from the sample location by the independent contractor' s excavator. The soil samples will be obtained from the "teeth-end" of the bucket. The samples will be transported under Chain-of-Custody protocol to a State of California certified laboratory for analysis. . The nine soil samples obtained will be analyzed by a lab for the presence and concentration of the following: TPH Purgeable by EPA Method 8015M/5030 (gasoline range) BTEX by EPA Method 8020 TPH Extractable by EPA Method 3550 (kerosene range) The samples will be analyzed on a normal laboratory schedule requiring approximately two weeks (ten working days) for completion. All soils excavated will be segregated into piles which are anticipated based on field screening to "contain" and "not contain" detectable levels of petroleum hydrocarbons. The soil will be placed on, and covered with, polyvisquene by the excavation contractor. 6) Composite Sampling of Soils Excavated During the Proposed Excavation Following the completion of the proposed excavation, the stockpiled soil will be composite sampled as described in Task 4 . For purposes of cost estimating, please assume the following volumes : 300 cubic yards of soil anticipated to not contain petroleum hydrocarbons (overburden) 600 cubic yards of soil anticipated to contain petroleum hydrocarbons The six soil samples obtained will be submitted to a lab to determine the presence and concentration of the following: TPH Purgeable by EPA Method 8015M/5030 (gasoline range) BTEX by EPA Method 8020 TPH Extractable by EPA Method 3550 (kerosene range)