Laserfiche WebLink
r <br /> Groundwater samples were collected from the on-site wells by EMC personnel Prior to sample <br /> collection, at least three well volumes of groundwater were removed from each well by a <br /> portable submersible pump or bailer During the purging of groundwater, pH, conductivity, <br /> temperature and turbidity were monitored at selected intervals This data is included in <br /> Appendix A along with the gauging data for the reporting period All equipment was cleaned <br /> using a solution of Alconox and water followed by two tap water rinses The actual <br /> groundwater samples were collected with a teflon bailer equipped with a bottom emptying device <br /> before being transferred into the laboratory supplied 40m1 VOA vials pending analyses The <br /> chain-of-custody documentation is presented in Appendix B. <br /> ANALYTICAL DATA <br /> Each groundwater sample was transported on ice in a light proof chest to American Analytics <br /> Laboratory The samples were analyzed for total hydrocarbons (TPHg) and volatile aromatic <br /> compounds (BTEX) by EPA methods 8015 and 8020, respectively Table 1 presents a summary <br /> of the TPHg and BTEX data The complete laboratory reports for the current samples are <br /> included in Appendix B �i`nthre�eof <br /> The results indicate a presence of the four wells on-site Detectable TPHg <br /> ranged from 6 2 mg/L to 47 0 g/L Detectable benzene concentrations ranged from 3,200 <br /> ug/L to 12,000 ug/L with the highest concentration noted in well MW-2 No detectable TPHg <br /> or BTEX were noted in sample MW-4 A benzene iso-con map is presented on Figure 3. An <br /> increase in the dissolved hydrocarbons concentrations was noted this quarter As previously <br /> stated, this increase could be a result of rise in groundwater beneath the site <br /> CLOSING <br /> Based on the site investigation and monitoring program, it appears that the shallow water zone <br /> found beneath the site exhibits the presence of dissolved hydrocarbons The monitoring events <br /> accomplished to data suggest the flow direction of groundwater across the site is generally to the <br /> south and south east Thrifty will continue to monitor the on-site wells on a quarterly basis <br /> If you have any questions, please contact me at (310) 923-9876 <br /> Very truly yours, \n F �'W <br /> X <br /> -�L' 1 <br /> <a�F 4164� <br /> Peter D'Amico <br /> Manager <br /> Environmental Affairs <br />