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A <br /> Northeast of the solvent tank excavation. Hydraulic 'ent information provided by the San <br /> Joaquin Flood Control District shows that the typical I ydraulic gradient in that area slopes to the <br /> Northeast. <br /> It isproposed that a 10" borehole be drilled in the east end of the driveway to a depth of 75'. Two <br /> 1 <br /> wells will be installed in the same borehole. MW#2A will be set at the bottom of the borehole @ <br /> 75'depth with 5'of screen.MW#2B will be set with the bottom of the screen at 55'of depth,with <br /> 20' of screen. A bentonite plug will be used between screens and separate the sample depths(see <br /> Monitoring Well Construction drawing,attached). <br /> Borehole #3 will be drilled in the parking lane of Ca ifornia Street, east of the Vogue Cleaners <br /> Building,and follow the same casing placement as M W#2(see Plot Plan attached).Borehole#4 <br /> will be drilled in the area south of the Vogue Clew en Building, and follow the same casing <br /> placement as MW#2 (see Plot Plan attached). <br /> SAMPLING SOIL BORINGS <br /> The San Joaquin Flood District records show that depth to groundwater varies from a low of 75 feet <br /> in 1978 to a high of 30 feet in 1986.We propose to sEmple the soil boring at 10 foot intervals for <br /> the first 20 feet of depth. Sampling will continue at ' intervals to a depth of 75 feet below the <br /> surface. <br /> Each BX soil sample tube will be capped with a lay of aluminum foil secured by plastic caps, <br /> sealed with duct tape, labeled for identification,and stored on ice for transport to the laboratory. <br /> All bore holes will be logged during the drilling using the standard soil classification method. Soil <br /> samples will be transported under a chain of custody Sherwood Labs of Hilmar,Ca.for analysis <br /> or analyzed on site. Samples from MW#2 , #3,and will be analyzed per EPA Methods 8020 <br /> (BTEX),and EPA Method 5030/8015{M)TPH line and Stoddard Solvent. Samples selected <br /> by PHS/EHD will be analyzed for EPA Method 8 60 for Oxygenates. Water samples will be <br /> analyzed by EPA 602(BTEX),EPA 5030 TPH-Gass ine and Stoddard Solvent and EPA Methods <br /> 8260 for Oxygenates, and Chlorinated Hydrocarbons. <br /> MONITORING WELL CONSTRUCTION <br /> MW#2A will be constructed of 2"PVC with a botto depth of 75'from the surface(See Drawing <br /> Attached). MW#2B will bottom at 55'below the .MW#3A&#3B,and MW#4A&#4B <br /> will follow the same criteria as MW#2A&MW . The screens section will have a sand filter <br /> and bentonite seal. The monitoring wells will be eloped <br /> ed and purged per PHS/EHD standards. <br /> Please contact this office if any question arise from I his work plan. <br /> Respectfully submitted, <br /> Foothill PAFe Ey <br /> NO.I <br /> Ervin Rifenb , RCE <br /> 2 <br />