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Site Background Information - Grewal's Market Page 3 of 6 Laboratory analysis of soil samples collected beneath the former USTs and product piping areas detected total petroleum hydrocarbons quantified as gasoline and diesel(TPH-g and TPH-d, respectively) at concentrations as high as 3,000 milligrams per kilogram (mg/kg) and 12;000 mg/kg, respectively. Benzene, toluene, ethylbenzene and xylenes (BTEX compounds) were detected beneath the former UST and product piping areas at concentrations as high as 290 mg/kg; methyl tertiary butyl ether (MTBE) and tert-butanol (TBA)were detected in the same areas at concentrations as high as 0.76 mg/kg.Analytical results of UST removal soil samples are summarized in Table 2. PREVIOUS SITE INVESTIGATION The following is a brief summary of the site assessment investigations conducted at the site to date: k • May 9997-As part of a preliminary site assessment, five soil borings (P-1 through P-5) were advanced to depths of 30 feet bsg to assess for petroleum hydrocarbon impact beneath the former UST area. Analytical results of the P4-30 foot soil sample detected xylenes at a concentration of 0.026 mg/kg; benzene was detected in sample P6-40 at a.concentration of 0.0068 mg/kg. MTBE was detected from P3-25 foot, P4-30 foot and P5-25 foot soil samples at concentrations as high as 0.28 mg/kg. Analytical results of soil samples are summarized in Table 2. Results of the May 1997 investigation were reported°in the AGE-prepared Preliminary Site Assessment Report- May 9997, dated 06 June 1997. • June 1999 - As part ofcontinued site assessment activities, four additional soil borings (P-6 through P-9) were advanced at the site to depths of.55 feet bsg to further assess the lateral and vertical extent of petroleum-impacted soil and ground water. Laboratory analysis of the P8-40 foot soil sample detected TPH-g and TPH-d at concentrations of 340 mg/kg and 37 mg/kg, respectively, while BTEX (i.e. toluene, ethylbenzene and xylenes) were detected at concentrations as high as 20 mg/kg. Residual BTEX compounds and MTBE were detected from the P6-40 foot soil sample at concentrations as high as 0.0082 mg/kg. Laboratory analysis of a grab water sample collected from P-8, detected TPH-g and TPH-d at concentrations of 1,900 micrograms per liter.(pg/1), BTEX compounds as high as 310 lag/I and MTBE as high as 52 pg/l. Analytical results of soil and ground water samples are summarized in Tables 2 and Al. Results of the June 1999 investigation were reported in the AGE-prepared Preliminary Investigation and Evaluation Report, dated 27 September 1999. • February 2000 - Ground water monitoring wells MW-1, MW-2 and MW-3 were installed at the site.to continue assessment of the lateral and vertical extent of petroleum-impacted soil and ground water; results of the February 2000 investigation were reported in the-AGE-prepared Ground Water Monitoring Well Advanced GeoEnvironmentnl,Inc. I