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SOIL SAMPLING PROTOCOL Soil Sampling by Drill Rig Review and confirmation of the proposed boring locations and special instructions are discussed with the client prior to sampling. Underground Service Alert (USA) and/or private utility locators are contacted to mark utilities in the area before beginning the drilling activities. Equipment used in drilling is steam cleaned prior to its arrival at the site. Equipment includes, but is not limited to, augers, bits, drilling rod, samplers and sample liners. The sampler is thoroughly cleaned with trisodium phosphate or Alquinox and rinsed with distilled water between sampling intervals. Each exploratory boring is drilled with a truck-mounted drilling rig using either solid flight or hollow stem augers. The boring is advanced to the desired sampling depth and the sampler is then lowered to the bottom of the hole. The sampler is driven a maximum of 18 inches by a 140-pound, rig-operated hammer falling 30 inches. The number of blows required to drive the sampler the final 12 inches is recorded on the boring log. The samplers commonly used are either a California-type sampler (3-inch or 2.5-inch) or a standard penetrometer (2-inch). If samples are collected for laboratory analysis, a California sampler equipped with brass or stainless steel liners is used. Upon retrieval, the sampler is disassembled into its component parts. One or more of the liners are selected for chemical analysis. The selected liners(s) are sealed with Teflon sheets, plastic caps, and tape. The samples are then labeled, logged on the chain-of-custody and preserved in a cooled ice chest. Each soil sample is classified in the field with the aid of the Unified Soil Classification System and a Munsell soil color chart. Soil descriptions are detailed on the boring log. Soil samples may also be field-screened for volatile organic vapor with a photoionization detector(PID) calibrated to a 100 ppm isobutylene standard. Soil samples or auger cuttings are placed into polyethylene bags or glass mason jars and allowed to accumulate (PID) headspace vapors for a period of five to ten minutes (temperature dependent). The instrument probe is inserted into the bags or mason jars and the maximum reading is recorded. Samples are held in the possession of ENGEO personnel until transfer to the analytical laboratory. The transfer is accomplished in one of three ways; on-site pickup by the laboratory, pick-up by the laboratory at ENGEO offices; or delivery to the laboratory by ENGEO. Each transfer of responsibility is documented on a chain-of-custody log that accompanies the sample(s). 4203-F3 March 25, 1997