Laserfiche WebLink
4. Conclusions <br /> The purpose of this supplemental site investigation pp t gatton was to further define the extent of <br /> petroleum hydrocarbons in soil and groundwater in the vicinity of the former Cardlock Gas <br /> Station site Based upon this investigation, the following conclusions can be made• <br /> • Groundwater flow direction continues to be toward the northeast across the <br /> site <br /> • Petroleum hydrocarbons were detected in groundwater samples collected <br /> from sampling locations SVi through SV7 downgradient from the former <br /> underground storage tanks (USTs) at the Cardlock station <br /> • Petroleum hydrocarbons were detected in sod samples collected from SV II , <br /> SV3, SV4, SV6, and SV7 located directly downgradient from the former <br /> USTs at the Cardlock site <br /> • • Soils and groundwater samples collected from beneath the southeastern <br /> corner of the Venetian Square Shopping Center indicate the low level <br /> presence of petroleum hydrocarbons <br /> • Because soil containing petroleum hydrocarbons exists only at depths <br /> greater than 23 feet bgs (within the capillary fringe zone), it appears that <br /> groundwater gradient and direction of flow were the primary factors which <br /> contributed to the offsite migration of petroleum hydrocarbons <br /> • Offsite soils have been impacted by petroleum hydrocarbons due to the <br /> forces of capillary tension These forces occur in the unsaturated zone, <br /> above the soil-groundwater interface, and cause the groundwater to be <br /> "wicked" or "drawn up" into the fine-grained soils. <br /> • Samples collected from Boring SV8 indicate that the former tank(s) at the <br /> Cardlock station are the likely source of the observed on site petroleum <br /> hydrocarbons Petroleum hydrocarbons released from the former Cardlock <br /> 9�ob2\940S49V.j,.,tdoa 9 940549 00 <br />