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' EXECUTIVE SUMMARY The project objectives were to further assess the lateral extent of impacted groundwater and to expand the on-site groundwater monitoring network, so that the groundwater flow direction and gradient could be calculated and monitored To achieve these objectives, one additional on-site ' groundwater table monitoring well (MW-3) was permitted, installed, surveyed, monitored and sampled, and the nearby municipal irrigation well was sampled ' Sods observed during the drilling of MW-3 consisted of massive intervals of clay, silt and fine sand mixtures to the total drilling depth of approximately 55 feet The groundwater-bearing interval is a fine sandy silt soil approximately 10 feet thick Groundwater does not appear to be present under confining conditions, and recharge was observed to be moderately strong On December 6, 2001, the depth to static groundwater across the site ranged from 45 50 feet ' below ground surface (bgs) in MW-3 to 46 91 feet bgs in MW-1 The corresponding groundwater surface elevation ranged from a high of 26 86 feet below mean sea level (msl) at MW-3 to a low of 27 70 feet below msl at MWA Between December 18, 2000 and December 6, 2001, the groundwater surface dropped an average of 3 13 feet The groundwater flow ' direction appears to be toward the south, away from the municipal irrigation well The three soil samples collected during the investigation did not contain detectable ' concentrations of any of the gasoline compounds analyzed In soil, significant concentrations of TPH-as-gasoline, BTEX and MTBE extend through the unsaturated soil beneath the former UST #3 Although the lateral extent of impacted sod is undefined, former UST#3 appears to be the lie primary source of gasoline in groundwater beneath the site The groundwater samples collected from MW-2 and MW-3 contained detectable concentrations of TPH-as-gasoline, BTEX compounds and MTBE Monitoring well MWA was not sampled due ' to the presence of 0 33-feet of free product The sample collected from the pressure tank of the municipal irrigation well did not contain detectable concentrations of any of the gasoline compounds analyzed ' In groundwater, gasoline hydrocarbons are concentrated as free product near former UST#3 Concentrations of gasoline compounds decrease with distance to the east and northeast of ' former UST#3 The lateral extent of impacted groundwater at the water table is undefined The vertical extent of impacted groundwater has not been investigated ' Based on these conclusions, Ramage Environmental recommends that a work plan be prepared to further investigate the lateral and vertical extent of impacted soil and groundwater, and to initiate soil and groundwater remediation at the site 1 ' 4