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A Shell service station and a 7-11 store that dispense gasoline are located at the respective southwest and northwest corners of the intersection of North Pershing Avenue and Rosemarie Lane Soil and groundwater investigations have been conducted at the Shell site TPH-g at concentrations up to 120,000 pg/L has been found in samples collected from MW8, which is located on the sidewalk adjacent to the eastern boundary of the Shell site, upgradient of Exxon RS 7-3942 3. SUMMARY OF RESULTS On 23 February 1993, wells MW8, MW10—MW12, RW1--RW4, P1, P2, V1, and V4 were purged and sampled. The samples were submitted to Pace Incorporated, where they were analyzed for Total Petroleum Hydrocarbons as gasoline (TPH-g) by DHS-modified EPA Method 8015 and for benzene, toluene, ethylbenzene, and xylenes (BTEX) by EPA Method 8020 The analytical results of the sampling of 23 February are presented in boldface type in Table I with results of previous analyses TPH-g and benzene concentrations are presented in Figures 2 and 3, respectively The laboratory analytical reports are included as Appendix A The field documents are included as Appendix B No petroleum hydrocarbons at concentrations greater than or equal to method detection limits were found in samples collected from the wells farthest downgradient of the site, MW 11 and MW 12 Concentrations of TPH--g in samples ranged from 1,000 pg/L in P2 to 150,000 µg/L �k in V4 Concentrations of benzene ranged from 58 gg/L in P2 to 15,000 pg/L in V4 Excluding the analytical results for the samples of groundwater collected from MW11 and MW12, petroleum hydrocarbon concentrations were lowest in the samples collected from P1 and P2, located along the western boundary of the site. The concentration of TPH-g in the sample collected from MW8, located adjacent to the Shell service station and upgradient of P1 and P2, was 49,000 pg/L, indicating that the Shell site is the likely upgradient contributor to the dissolved contaminant plume immediately west of the Exxon site Petroleum hydrocarbon concentrations of the 23 February sampling are consistent with those of previous sampling events. LPH was detected in four wells (V 1, V2, V4, RW3) during the previous gauging/sampling event of 8 October 1992, but no LPH was detected on 23 February Water levels in all wells on and off the site (with the exception of the air sparging/vapor extraction cluster wells) were measured on 23 February Measurements and groundwater elevations for 23 February are presented in boldface type in Table 1 with previous data, and in Figure 4 The inferred direction of groundwater gradient is to the east-northeast at a Imagnitude of 0 01, which is consistent with previous data Groundwater elevations have increased 3 3 feet from the previous quarter ' Two letters have been sent and received by certified mail and five phone calls have been made to Robert Pratt of Beverly Enterprises, property managers of the Chateau Convalescent Hospital Three weeks ago Mr Pratt returned one of EA's phone calls and said that he would respond to our request—no other phone calls have been returned since then I ' 73942(IYQ293/CX 3 2