Laserfiche WebLink
I <br /> fl <br /> t <br />. Mr Kyle Christie Project 0805-15101 <br /> September 13, 1995 <br /> Page 2 <br /> used these data to evaluate changes in concentrations of dissolved gasoline hydrocarbons <br /> in the groundwater and changes in the flow direction and groundwater gradient <br /> On December 5, 1994, a representative from GTI measured depths to water in wells <br /> MW-1 through MW-4 On July 28, 1995, a representative from EMCON measured depths <br /> to water in these wells and collected groundwater samples from the wells for laboratory <br /> analyses of hydrocarbons Floating product was not observed in groundwater samples <br /> collected from these wells (see Table 1) EMCON's sampling and analysis procedures are <br /> presented in Appendix A <br /> The groundwater elevations were used to evaluate the direction of groundwater flow and <br /> gradient beneath the site (see Table 1) The groundwater gradient at the time of <br /> measurement was 0 002, and the direction of flow was toward the north to northwest (see <br /> Figure 3) This flow direction is consistent with the flow direction obtained last year <br /> Groundwater elevation increased approximately 2 01 feet from the previous sampling <br /> event (July 1994) <br />• The groundwater samples were analyzed at Columbia Analytical Services in San Jose, <br /> California, for total petroleum hydrocarbons as gasoline (TPHG), and benzene, toluene, <br /> ethylbenzene, and total xylene isomers (BTEX) using Environmental Protection Agency <br /> Methods 50301DHS LUFT and 503018020, respective., Coptes of the chain-of-custody <br /> records and laboratory analysts reports are presented in Appendix B <br /> Results of laboratory analyses are presented in Table 2 Results of the analyses indicated <br /> that TPHG and BTEX concentrations were below laboratory detection limits in <br /> groundwater samples collected from wells MW-I through MW-4 <br /> CONCLUSIONS <br /> Results of this monitoring event indicated that dissolved gasoline hydrocarbons are <br /> consistent with previous sampling events The groundwater gradient and flow direction <br /> data were also consistent with those previously obtained <br /> ANTICIPATED WORK <br /> • ARCO will continue to perform semi-annual monitoring and annual <br /> groundwater sampling at the site The next monitoring event is scheduled for <br /> December 1995 <br /> SACU IARC01602Ntr1y16020 qm3-95 pas <br />