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A-2 Soil Classification As the samples are obtained in the field,they are classified by the field geologist in accordance with the Unified Soil Classification System. Representative portions of the samples are then retained for further examination and for verification of the field classification. Logs of the borings indicating the depth and identification of the various strata, the N value, and pertinent information regarding the method of maintaining and advancing the borehole are prepared. Soil Sample Screening After the soil samples in Ziploc®type bags have been brought to ambient temperature, the headspace vapors in the bag are screened with a photoionization detector equipped with a 10.2 eV lamp. The. corner of the bag is opened and the detector probe immediately placed within the headspace. The highest observed reading is recorded. Soil Cuttings From Drilling Operations Soil generated during drilling operations will be stockpiled on-site. The stockpile is typically set on asphalt and covered by plastic sheeting in a manner to prevent rain water from coming in contact with the soil. If no asphalt is available the soil is placed on plastic sheeting and covered in the above method. The soil will remain on-site until the proper method for disposal is assessed. Stockpile Soil Sampling Stockpile soil sampling is performed under the direction of a registered geologist or civil engineer. Prior to collecting soil samples Delta personnel will measure and calculate the volume of soil in the stockpile(s). The stockpile(s) is then divided into sections containing the predetermined volume sampling interval (50, 100, 200, 500 yd3, etc.). Soil samples are typically collected from 0.5 to 2 feet below the surface of the stockpile. In some instances two to four soil samples may be collected from each sampling interval and composited into one prior to laboratory analysis. The soil samples are collected in cleaned,brass or stainless tubes of varying diameter and lengths(typically 2 x 6 inches)or other appropriately cleaned sample containers. A hand-driven sampler holding the sample container may be used. To reduce the potential for cross-contamination between samples,the sampler is cleaned between each sampling event. Upon recovery,the sample container is sealed to minimize the potential of volatilization and cross-contamination prior to chemical analysis. Soil sampling tubes are typically CL006.KS