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V Z MA i. Working To Restore Nature o The new wells will be surveyed, properly developed, purged and sampled. The 6' groundwater samples collected from the wells will be analyzed for BTEX (EPA Method 8020) and TPHd and TPHg (EPA Method 8015). y o The hydraulic gradient and groundwater flow direction at the site will be verified from surveying and monitoring data collected during field activities. 60 2.1.1 Groundwater Monitoring Well Installation Methodology 6W Three soil borings will be drilled to approximately 16 feet below surface grade on the west, north west and northeast, sides of the former tank excavation. The locations are near areas where previous investigations indicated residual soil contamination may exist. Three y additional borings which will be completed as monitoring wells, will be drilled to approximately 30 feet below grade, or 15 feet into the water zone. Two of the three borings completed as wells will be located in the estimated downgradient direction from the former tank excavation and one will be located in the estimated upgradient direction. The proposed location of the wells are shown on Plate 3. Drilling will be conducted by Spectrum Exploration, Inc. (State C57 license no. 512268). V using a hollow-stem auger drill rig. All downhole and sampling equipment will be decontaminated to avoid the possibility of cross-contamination. A field geologist will be present to log all drill cuttings and soil samples utilizing the Unified Soil Classification System. Soil samples will be collected above the water table at 5-foot intervals and below the 6" water table at selected intervals in accordance with the Soil Sampling Protocol (Appendix I). The soil samples collected at the capillary fringe will be submitted for laboratory analysis; `, additional samples will be analyzed from areas which exhibit physical evidence of soil contamination [olfactory. soil discoloration or Photoionization Detector (PID) readings]. Soil .r analysis will be conducted for BTEX (EPA Method 8020) and TPHg and TPHd (EPA Method 5030/8015). Descriptions of soil types encountered, sample collection intervals, and well construction details will be recorded on boring logs. V All drill cuttings will be placed on plastic sheeting, covered with same, and stored on-site pending laboratory results. Water used to clean the augers after drilling the borings will be collected and stored in 55-gallon drums approved for hazardous liquid storage pending �• laboratory analysis. Following completion of the three 16-foot deep soil borings, they will be backfilled to surface with cement grout. V 4 r.r