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STANDARD OPERATING PROCEDURE SOIL BOREHOLE DRILLING, REMEDIATION WELL INSTALLATION, AND SOIL, SAMPLING Drilling and Soil Sampling Permits, Site Safety Plan. Utility Clearance ATC Associates hie. (ATC) obtains all the required permits, unless otherwise contractually directed, ATC prepares a site specific Site Safety Plan detailing site hazards, site safety and control, decontamination procedures, and emergency response procedures to be employed throughout the defined phase of work. At least 48 hours prior to drilling. Underground Service Alert (USA) or an equivalent agency is notified of the planned work. ATC attempts to locate all underground and aboveground utilities by site inspection (in conjunction with it's' subcontractors and knowledgeable site managers, if available), and review of site as- built drawings. ATC may employ a private, professional utility locator to refine the site utility inspection. Drilling Equipment All soil borings are drilled using a Track-mounted hollow-stem auger drill rig, unless site conditions warrant a different drilling method. Subsurface conditions permitting, tire first five feet of each boring is advanced using a hand-auger or post-hole digger. All drilling equipment is inspected daily and maintained in safe working condition by the operator. All down-hole drilling equipment is steam cleaned prior to arriving on site. Working components of the drill rig near the borehole, as well as augers and drill rods are thoroughly steam cleaned bchveen each boring location. All ATC drilling and sampling methods are consistent with ASTM Method D4 452-80 and local, stale and federal regulations. Soil Sampling and Lithologic Description Whenever possible and approved by the appropriate regulatory agency, the first ATC boring to be drilled at a site is continuously cored to obtain a complete lithologic description. Otherwise, soil samples are typically collected every 5 feet to the total depth explored, using brass tubes fitted in a California-modified split- spoon sampler. If copper or zinc contamination is the subject of the investigation, stainless steel liners are used instead of brass. Additional soil samples may be collected based upon significant changes in lithology or in areas of obvious soil contamination. During soil sample collection, the split spoon sampler is driven 18 to 24 inches past the lead auger by a 140-pound hammer falling a minimum of 30 inches. The number of blows necessary to drive the sampler and the amount of soil recovered is recorded on the Field Exploratory Soil Boring Log. The soil sampler and liners are cleaned with an Alconox® solution and rinsed with tap water prior to each sampling event. New liners are used whenever a soil sample may be retained for laboratory analysis. Soil samples selected for laboratory analysis are sealed on both ends with Teflon tape and plastic end caps. The samples are labeled, documented on a chain-of-custody form and placed in a cooler for transport to a state-certified analytical laboratory. Soil contained in remaining liners is removed for lithologic descriptions (according to the Unified Soil Classification System). Additional soil is screened for organic vapors by placing approximately 30 grams of soil in a sealed plastic bag or a glass jar sealed with aluminum foil. The bag or jar is left undisturbed for approximately 15 minutes, in the sun if possible. The headspace in the bag is accessed in a manner to minimize entry of outside air, and is tested for total organic vapor using a calibrated photo ionization detector (PID). The results of the field screening are noted with the lithologic descriptions on the Field Exploratory Soil Boring Log. On encountering an impermeable (clayey) layer three feet or more in thickness below a saturated permeable layer, where the impermeable layer is considered to be a possible confining layer for an underlying aquifer, drilling is halted until a decision to proceed is obtained from the project manager. This process minimizes