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Mr Jeffrey Wong Page 4 of Borings SB2 through S135 were backfilled to the ground surface with neat cement grout Soil cuttings were contained on site by placing on, and covering with plastic sheeting All down-hole drilling and sampling equipment was decontaminated by steam cleaning Rinsate collected from decontamination procedures was contained in 55-gallon drums The drums are currently stored on site pending proper disposal 3.2 Well Construction Prior to the construction of MW 1, the boring was backfilled to the desired depth with coated bentonite pellets Based on statigraphy and depth to groundwater measurements observed in boring SBI, well MWI was screened from 45 to 65 feet bgs The well was constructed of 2-inch diameter, Schedule 40 PVC casing and 0 020 inch slotted screen The filter pack consisted of#3 silica sand The annular seal contained 2 feet of bentonite overlain by neat cement grout to the ground surface The well construction log is included in Attachment A 3.3 Well Development and Groundwater Sampling On March 2, 2000, the well was monitored, developed and sampled Prior to well development, the groundwater was measured at a depth of 42 16 feet bgs The new well was developed by surging and pumping until turbidity was minimized Temperature, pH, and electrical conductivity were measured during the well development process and allowed to stabilize before collecting samples The groundwater elevation observed in the well was above the top of the well screen, however, during development, the water level dropped significantly to approximately 60 feet bgs The decrease in the groundwater elevation indicated that a cone of depression developed This allowed the potentiometric surface to come into contact with the screened interval, and provide a representative sampling environment Groundwater was collected from the well after recovery The samples were submitted to Argon Laboratory for analysis of TPHg, BTEX, and gasoline oxygenate additives Purge water generated during field activities was placed into a DOT approved 55-gallon drum which is currently stored on site pending disposal Groundwater monitoring and well development logs are included in Attachment B 4.0 RESULTS OF INVESTIGATION 4.1 Subsurface Conditions The general stratigraphy at the site consists of lean clay and silt from the surface to approximately 18-20 feet bgs Underlying this, a layer of well-graded sand with silt was encountered in the three borings that penetrated to that depth In SB 1 alternating layers of well- graded sands and silts were present from approximately 24 feet to approximately 80 feet where a silty clay unit was identified Groundwater was initially encountered at a depth of approximately 50 feet and subsequently rose to approximately 42 feet bgs data\grounzelhanyslsumrpt doe