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' 02 September 2003 . AGE-NC Project No.,98-0468 Page 5 of 11 ' of 65 micrograms per milligram(µg/mg)and 110 ag/mg in MW-4 at 17.5 and 20 feet bsg,respectively. Concentrations of TPH-d were detected in two of the eight ground water samples. TPH-d was reported at concentrations of 570 µg/1 and 130 µg/1 in samples B-2 and B-3,'respectively. On 18, 20 and 23 February and 08 Marcia 2002, three soil borings(B8,B9 and B10)were advanced at the site.The following is a chronology ofthe investigation: On 18 February 2002,one soil borings ' (B8)was advanced to a depth of 60 feet bsg and a discrete ground water samples was collected from boring B8 at 55 feet bsg with a HydroPunch water sampling assembly.On 20 February,the same soil boring B8 was advanced to a depth of 71 feet bsgand sampled at total depth. Also on 20 February, one soil boring (139) was advanced to a depth of 60 feet bsg and a grab ground water sample was collected at the total depth. On 23 February, soil boring B8 was abandoned and grouted and soil boring B9 was advanced to a depth of 70 feet bsg and completed as a depth discrete monitoring well ' screened from 70 to 75 feet bsg. On 08 March 2002,one additional monitoring well(MW-10)was installed east of co-located B9, MW-8 and MW-9 cluster, screened from 55 to 60 feet bsg. ' MTBE.was detected by EPA Method 8020 in the grab ground water samples B8-55 and B9-55 at concentrations of 170 µg11 and 41 µg/l, respectively. However, MTBE was not detected by EPA '. Method 8260 in sample B8-70. MTBE was detected at a concentration of 1.6µg11 by EPA Method , 8260 in sample B8-70 . TPH-g; BTEX and other fuel oxygenates were detected in the samples. Figures 4 and 5 depict the lateral extent of dissolved TPH at the site. Figure 2 depict the lateral ' extent of dissolved MTBE. Analytical data for the soil and ground water are summarized in Tables 1 and 2. Soil boring logs are included in Appendix A: ' 3.0. GROUND WATER MONITORING ' Between June 1994 and the April 2003,ten ground water monitoring wells have been installed and ; sampled for petroleum hydrocarbons. Initial ground water samples were collected in June 1994. To date, a total of fourteen ground water monitoring events have been conducted at the site. Depth to ' ground water has ranged between 7.04 and 14.01 feet bsg and ground water flow direction has been consistently northeast at a gradient of approximately 0.02 ft/ft. ' Petroleum hydrocarbon compounds were detected a maximum concentrations during the follownig monitoring events,TPH-g at 290µg/l(MW-6 in April 2002),TPH-d at 61µg/1(MW-4 in November 1999) BTEX compounds have been detected at the following maximum concentrations: benzene ' (MW-4:7.7µg/1-11199),toluene(MW-6:2.3 µg11-03/01)and xylenes(MW-6.1.9µg/1-03/01).MTBE has been detected in wells MW-3 through MW-10 at concentrations ranging from 0.84 µg/l,(MW-8 in September 2002) up to 1,100 µg/l (MW-4 in November 1999). ' Advanced GeoEnvironmenlal,Inc.