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Soil samples will be examined for lithologic description and field screened for undifferentiated volatile organic compounds(UVOCs)using a photo-ionization detector(PID). Select soil samples collected from boring CPT-1 B will be submitted for laboratory analysis.Drilling and soil sampling details are presented in greater detail in Appendix B. SOIL BORING DRILLING Boring BSW-1 will be manually excavated to approximately 4 feet bgs in order to avoid any subsurface obstructions and then straight drilled with 8-inch diameter hollow stem augers to a final depth of approximately 80 feet bgs at the location shown on Figures 3 and 3A. Drilling will be conducted using a limited access hollow stem auger drilling rig. WELL CONSTRUCTION Subsequent to drilling boring BSW-1 to its final depth,biosparge well BSW-1 will be constructed with a 2-inch diameter, Schedule 40 PVC screen and blank casing. Five feet of 0.020-inch slotted casing will be placed in the bottom of the borehole from approximately 75 feet bgs to 80 feet bgs. Based on previous investigations, sands are present from approximately 65 to 85 feet bgs with a clay lens from 70 to 75 feet bgs in the vicinity and location of well MW-16. The screen interval will be adjusted to be set in the sand layer if needed based on the CPT data. Blank casing will extend from the top of the slotted screen casing to just below the ground surface. Subsurface lithology and proposed biosparge well B SW-1 are shown on Figure 5. Sand will be placed in the annular space between the screened casing and the borehole wall and will extend approximately 3 feet above the top of the screened casing interval. Surging and bailing will be conducted during the placement of the sand to ensure proper consolidation of the sand pack. A 3-foot seal of time release bentonite pellets will be placed in the annular space above the sand. Neat cement will be placed over the hydrated bentonite pellets to approximately 1-foot bgs. Wells will be completed with a traffic rated well box set in concrete. WELL DEVELOPMENT Newly-installed well BSW-1 will be developed by bailing and pumping no sooner than 48 hours after well installation in accordance with the procedures described in Appendix B. WELL SURVEY Additionally, newly-installed well BSW-1 will be surveyed for elevation (relative to a City, County, or Federal benchmark) and for location, using Global Positioning System methodology. The survey will be conducted in accordance with SWRCB GeoTracker protocol. SOIL AND GROUNDWATER DISPOSAL/RECYCLING Soil cuttings generated during drilling operations will be temporarily stored on-Site in a roll-off bin. Following the receipt of laboratory analytical data, the soil cuttings will be profiled, manifested, and transported to an appropriate State-licensed recycling facility or landfill. FREY Environmental, Inc. 4 Project No. 1175-01