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qW *.d PROPOSED SCOPE OF WORK DRILLING PROJECT RMC proposes to drill and sample a minimum of eight soil borings at the subject site. RMC will hire a State-licensed drilling contractor to progress these borings utilizing a reverse-circulation, air-percussion drilling rig. An air percussion-drilling rig has been found to be best suited for the gravel and cobble-rich soil found in this area of the Central Valley. The approximate locations for the borings are shown in Figure 2. All borings will be advanced to approximately 40 feet bsg. This depth may vary based on the results of organic vapor analyzer (OVA) readings of the return cuttings taken during the drilling. Two of the borings will be further drilled to a depth of 140 feet bsg then converted into additional groundwater monitoring wells for the site. A field technician under the supervision of a State-registered geologist will perform all fieldwork. Return cuttings will be continuously logged using the USC system of soil classification. Detailed logs will be prepared to record the soil type, OVA readings, and any pertinent field observations. Original log sheets will be presented in the final report submitted to EHD. Soil Sampling Cutting returns will be collected and sampled with an organic vapor analyzer (OVA) [Foxboro Model 88] on a regular basis. The OVA probe will be pushed into the cuttings and left for approximately thirty seconds to determine if discernable hydrocarbon vapors can be detected in the pore space of the soil material. Cutting returns will be collected directly from the sample cyclone on the drill rig into a large rubber tub. The contents of the tub will be changed out every five feet and checked for soil type, odor and OVA response. Soil samples for chemical analysis will be taken directly from the soil cuttings in the rubber tub. If a petroleum vapor is encountered a soil sample will be taken every five feet until either the vapor is no longer detected or first water is reached in the case of the two proposed monitoring wells. If no odors are encountered in the cuttings a sample will be taken every twenty feet. All soil samples will be collected into a laboratory-cleaned glass-sampling jar, labeled, and placed into a chilled ice chest for analysis at a State-certified laboratory. Strict chain-of-custody protocol will be followed during all phases of sample handling. RMC plans to extend borings B5 and B8 (see Figure 2)to approximately 140-feet bsg and complete them as two additional groundwater-monitoring wells for the site. The location of the two new monitoring wells was chosen to improve the triangulation of the groundwater flow gradient. Upon reaching the water table drilling will be temporarily halted for at least thirty minutes to recover pressure equilibrium. After that recovery period measurements will be taken with an electronic water tape to determine the depth to the water level. A clean bailer will then be lowered down through the center drill tubing, to observe and measure any presence of floating petroleum product thickness. A sample of the groundwater will also be taken at that time for chemical analysis.