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Appendix A - Standard Operating Procedures LI Page lofl Updated OB/13/2013 anteagroup 'III STANDARD OPERATING PROCEDURES F1 Utility Locating Prior to drilling, boring and excavation locations and an approximate 15-foot by 15-foot box are marked with white paint or other distinct marking and cleared for underground utilities through Underground Service Alert (USA). In addition, Antea Group will contract an independent locator services 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 air-knifed, or carefully advanced with a hand auger if shallow soil samples are necessary, to help evaluate the borehole location for - 1 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 l 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. J Undisturbed soil samples selected for laboratory analysis are cut away from the acetate sample liner using a hacksaw, or _I 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 j 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 Advancement using n' Drilling Pre-cleaned heavy-walled down-hole casings (typically 6 to 8 inches in diameter) are advanced using a sonic head. A smaller diameter core barrel (typically 4 to 6 inches in diameter) is advanced through the inside of the down-hole casings I to remove the soil cuttings from the borehole for sample collection and evaluation of subsurface conditions. --1I During drilling, soil samples are collected continuously using the sonic core barrel. A physical description of soil IJ characteristics (i .e. moisture content, consistency or density, odor, color, andplasticity), drilling difficulty, and soil type as a function of depth are described on boring logs. The soil cuttings are classified in accordance with the USCS and field screened for organic vapors using a PID. 1