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' Visual observations will include documenting the presence of hydrocarbon sheen or floating ' product and identifying any unusual odors Once the groundwater grab sample is collected, the boring will be tremae grouted using a cement grout The groundwater grab samples will be ' tested for TPH-gasoline, TPH-diesel, TPH-motor oil, BTEX, and MTBE as described in Table I 4.3 Phase 2 —Subsequent Investigation The Phase 2 information may be needed to evaluate additional groundwater parameters such as ' flow direction, gradient, and water quality t4.31 Groundwater Well Construction and Development ' If needed, monitoring wells will be installed based on the results of the phase 1 investigation The monitoring well(s) will be constructed within the uppermost water-bearing unit to a depth of ' approximately 20 feet The well(s) will consist of 2-inch diameter flush-threaded schedule 40 polyvinyl chloride (PVC) casing with 0 01-inch machine slotted screen placed at depths of 5 to ' 20 feet bgs This screened interval correlates with the offsite wells The remainder of the well will consist of blank casing The screened interval should extend a minimum of I foot above the ' top of the groundwater level The well screen will be fitted with a flush-threaded bottom cap A No 2-12 sand pack will extend from the bottom of the screen to I-foot above the top of the ' screen One foot of bentonite pellets will be placed above the sand and hydrated with tap water The remainder of the annular space will be sealed using a neat cement grout Protective casing ' will be installed with a lock ' The groundwater welI(s)will be developed once the wells have been allowed to cure for at least 48 hours Water will be removed from the well by bailing, pumping, or surging until it is clear ' of sediment The development water will be monitored for turbidity (removal of fine materials), and the temperature, pH, turbidity and conductivity will be monitored until measurements ' stabilize (temperature within 1 degree centigrade, pH within 0 1 pH unit, turbidity within 10 percent, and conductivity within 3 percent) All field observations including water quality data, Field Cnvestigatton Work Plan 8 2 September 2003 ' TREADWELL&ROLLO,INC