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pvtng. s+ SECTION 3 CONCLUSIONS AND RECC)MMENDATIONS The objectives of this investigation were to confirm the presence of contc.minated soil identified by WGR near the southwest corner of the former tank locations and to determine if groundwater has been impacted by product in the soil. The presence of diesel near tbP southwest corner of the former tank locations has been confirmed by the soil sample collected from boring B-16. Groundwater at this location was also found to contain diesel. • The distribution of diesel in the groundwater among the five locations sampled is consistent with the southerly groundwater flow direction measured on March 7 and again on March 29, 1991. Of the five groundwater sampling locations, only the HydroPunch sample at B-16 is directly downgradient of the former tank location. The four existing monitoring wells are upgradient at the present time. Boring B-16 is located near the property line and the additional borings and wells are likely to be off site. Due to dropping groundwater levels, these wells now contain 3 to 4 feet of water and may likely be unusable within a short period of time. Because the wells have not yielded information about diesel in groundwater as shown in the HydroPunch sample B-16, ERM-West makes the following recommendations: ° Close the four existing wells; • Collect soil samples from approximately 25 feet in a minimum of 6 soil borings; • Collect groundwater samples from the soil borings by utilizing the HydroPunch; Analyze the soil and groundwater samples with i� portable on-site laboratory; ° Install new monitoring wells to an approximate depth of 40 feet with locations based on the analyses of soil and groundwater samples; and ° Develop and sample the wells approximately 30 days after well . ------- - 3-1