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0 GF—C7MA1 RIX soil forming a portion of a temporary equipment access ramp The ramp was constructed for equipment used to refurbish two anhydrous ammonia storage tanks at a nearby facility (see WGR letter in Geomatrix, 2004) On May 21, 2004, wells MW3-6,MW3-5, MW3-1, MW3-2, and MW3-4 (Figure 2) were purged and sampled by WGR in that order Depth to groundwater was measured in the site monitoring wells before purging Prior to sampling each well, the presence of separate-phase petroleum hydrocarbon was assessed with a disposable bailer About 100 gallons of water was purged from each well using a dedicated stinger and vacuum truck Each dedicated stinger is stored on the site in its own sealed plastic bag Suction on the vacuum truck line remains on during purging and while making and breaking the connection with the individual stingers After purging the initial 50 gallons from each well, a new, clean disposable bailer was used to collect water from each well for measurement of field parameters Measured field parameters, which generally comprise electric conductivity (EC), pH, temperature, dissolved oxygen (DO), and oxidation reduction potential (ORP), were recorded on field data sheets (Appendix A) During the May sampling round, no ORP measurements were taken by WGR, owing to • unavailability of an ORP meter After the first set of field parameters was collected and water levels had recovered, an additional 50 gallons of water was purged with the dedicated stinger New clean disposable bailers were used to collect groundwater samples for field parameters and laboratory analysis of total petroleum hydrocarbons quantified as gasoline (TPHg) and benzene, toluene, ethylbenzene, and xylenes (BT'EX) Groundwater samples collected by WGR were preserved and transported under chain-of-custody (Appendix B) procedures to Precision Enviro-Tech Analytical Laboratory (PET) in Stockton, California, a state-certified laboratory The groundwater samples from the five sampled site monitoring wells were analyzed by PET for TPHg and BTEX using U S Environmental Protection Agency (EPA) Method 8260B In addition to required quarterly sampling conducted by WGR, Geomatrix collected groundwater samples from the site monitoring wells On April 1, 2004, Geomatrix collected groundwater samples from groundwater monitoring wells MW3-2, MW3-1,MW3-6, MW3-4, and MW3-5 in that order On May 18, 2004, Geoznatrnx collected groundwater samples from groundwater monitoring wells MW3-2, MW3-5, and MW3-4 in that order Geomatrix used a clean non- dedicated submersible pump to purge groundwater at about 1 to 2 gallons per minute from each well The wells were purged until at least four well casing volumes were removed and field parameters consisting of pH, temperature, and EC had stabilized (Appendix A) Field I TROJECT1G(WsW17 00016437 21 doe 2