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Appendix 8 - Standard Operating Procedures O Page 1 o/ 2 Updated 08/1/2014 antea'group STANDARD OPERATING PROCEDURES Utility Locating Prior to drilling and excavation, locations and an approximate 15 by 15-foot box are marked with white paint or other distinct markings and cleared for underground utilities through Underground Service Alert (USA). In addition, Antea Group will contract an independent locator service to clear boring or excavation locations of subsurface assets. The first five feet (or more in instances where utilities are suspected in close proximity) of each borehole are cleared using an air-knife and vacuum truck, or carefully advanced with a hand auger if shallow soil samples are necessary, to help evaluate the borehole location for underground structures or utilities in accordance with Antea Group's subsurface hazard avoidance policy. Subsurface Investigation Methods — GeoProbe®, Sonic, Hollow Stem Auger Drilling, Sampling, and Borehole Completion Borehole Advancement using GeoProbe® Pre-cleaned push rods (typically one to two inches in diameter) are advanced using a hydraulic direct push-type rig for the purpose of collecting samples and evaluating subsurface conditions. The sample barrel located at the leading end of the drill rod serves as a soil sampler, and an acetate liner is inserted into the sample barrel rod prior to advancement of the push rod. Once the sample is collected, the rods and sampler are retracted and the acetate sample tubes are removed from the sampler. The sample barrel is then cleaned, filled with clean sample tubes, inserted into the borehole and advanced to the next sampling point where the sample collection process is repeated. Undisturbed soil samples selected for laboratory analysis are cut away from the acetate sample liner using a hacksaw, or equivalent tool, in sections approximately 6 inches in length. The 6 inch samples are lined at each end with Teflon® sheets and capped with plastic caps. Labels documenting project number, borehole identification, collection date, and depth are affixed to each sample. The samples are then placed into an ice-filled cooler for delivery under chain-of-custody to a laboratory certified by the State of California for analysis. The remaining collected soil that has not been selected for laboratory analysis is logged using the United Soil Classification System (USCS) under the direction of a State Registered Professional Geologist, and is field screened for organic vapors using a photo ionization detector (PID), or an equivalent tool . Borehole Completion Upon completion of drilling and sampling neat cement grout, mixed at a ratio of 5 gallons of water per 94 pounds of Portland cement, is introduced to the borehole via a tremie pipe through the center of the outer casing rods or augers. The outer rods or augers are retracted as the grout is introduced to the bottom of the boring to prevent the cross contamination of encountered water bearing zones. Displaced groundwater is collected at the surface and placed into Department of Transportation ( DOT) approved 55-gallon steel drums, or an equivalent storage container. In areas where the borehole penetrates asphalt or concrete, the borehole is capped with an equivalent thickness of asphalt or concrete patch to match surface grade.