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07 August 2006 AGE-NC Project No. 01-0839 Page 2 of 4 potential contaminant migration pathways to assess the lateral and vertical extents of hydrocarbon- impacted soil and ground water at the site. Based on the distribution of hydrocarbons encountered to date during the ongoing investigation, AGE proposes to advance the CPT soil borings in the following locations: • CPT-1 will be advanced to a total depth of 100 feet bsg,to be located approximately 35 feet east of monitoring well MW-1 in the planter on the eastern edge of the property,to verify the lateral extent of the plume to the north; • CPT-2 will be advanced to a total depth of 150 feet bsg,to be located between wells MW-1 and MW-4,approximately 30 feet northwest of monitoring well MW-4 near the source area to define the vertical extent of contaminated soil and ground water at the site. The initial boring at each location will be a CPT sounding; soil parameters such as cone bearing, sleeve friction, friction ratio, and pore water pressure will be measured as the cone penetrometer is advanced. The CPT will acquire a continuous lithologic record to define the hydrologic units. Additional soil borings (for soil and grab ground water sample collection) will be located no more than 3 feet from the initial CPT sounding. Based on the CPT findings, discrete soil samples will be collected at various depths between 25 feet and 100 or 150 feet bsg based on significant lithologic variation. Soil samples will be collected utilizing a 2-inch diameter piston soil sampling assembly loaded with pre-cleaned brass sleeves. Upon soil sample retrieval, a brass sleeve will be removed from the sampler.The ends of the brass sleeve will be immediately covered with Teflon or aluminum sheets, sealed with plastic end caps, secured with tape, and placed in a chilled container for transportation to a California Department of Health Services (DHS)-certified laboratory. Each sample sleeve will be labeled with the location,boring designation,depth,time,date,and sampler's initials. Total depths of the borings may vary according to hydrogeologic conditions encountered during drilling activities. Soil sample duplicates will be monitored for the presence of organic vapor using a photo-ionization detector (PID) and the readings will be recorded on boring logs. Soil sample duplicates will be visually described by an AGE geologist using the Unified Soil Classification System (USCS) and recorded on the boring logs. Grab ground water samples will be collected from within 2-inch diameter hollow-stem rods equipped with a 5-foot, extendable 0.010-inch slotted polyvinylchloride (PVC) screen. Grab ground water samples will be collected in selected intervals of saturated porous and permeable material. The screen will be exposed at the selected depths and a stainless steel bailer will be used to retrieve the water samples. Ground water samples for appropriate EPA analyses will be collected into 40-m1 volatile organic analysis (VOA) vials containing 0.5 ml of 18% hydrochloric acid solution as a sample preservative. After collection, the ground water samples will be appropriately labeled and Advanced GeoEnvironmental,Inc.