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Geon ical7echnics 2nc. . • Page 3 ' 5inc�air Trucking-QMR Project No.320.2 November 8, 1999 ' A stainless steel bailer was used to collect each sample. Bailer cleanliness was assured by collecting a bailer blank(pouring distilled water through the bailer and collecting it in a VOA vial) prior to collecting the analytical sample. ' Extreme care was exercised while collecting samples to prevent agitation of the water contained in the bailer and to minimizes sample aeration during transfer of the sample into the bottles. Water samples were transferred from the bailer into 40-m1 VOA vials preserved ' with hydrochloric acid. All samples were checked for headspace bubbles, labeled, inserted into foam holders and placed in an ice chest cooled to 4°C for transport to the laboratory. The sampling technician wore disposable gloves while collecting all samples. A chain of custody document, listing all samples collected and their intended analyses, accompanied the samples from field to the laboratory, thereby providing a means to track ' their movement and insure their integrity. 1.3 Laboratory Analyses ' The groundwater samples were delivered to BSK Labs (Department of Health Services Certification No. 1180), of Fresno, California, for analysis. The samples were analyzed using the following methods: • EPA method 602 - BTEX • EPA method 5030/8015(m) -TPH-Gasoline • EPA method 8260 - OFCs The detection limits for the above analyses are listed in Table 1 of Appendix A and the lab ' data is presented in Appendix B. ' 2.0 FINDINGS AND DISCUSSION The results from the latest round of monitoring event show that: Floating product has not been detected in any of the monitoring wells. ' • Low concentrations of aromatic hydrocarbon compounds (BTEX) are present in MW-1 while only trace concentrations were found in MW-4. • The concentrations of TPH-G in MW-4 has dropped significantly since the first monitoring event, suggesting that the contamination plume may be smaller then originally thought from the February 1999 monitoring event results. • Total petroleum hydrocarbons as gasoline (TPH-G) are present only in MW-1. • The five oxygenated fuel compounds (OFCs) tested for were not detected in any of the ' monitoring wells. • The upgradient monitoring wells, MW-2 & 3, did not contain any of the petroleum hydrocarbon compounds tested for. ' • _The domestic water well did not contain any of the petroleum compounds tested for. 1