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total depth of 56 6 feet, and constructed with 2-inch diameter PVC casing and • 0 020 inch slotted well screen Both wells were screened from a depth of 25 feet below ground surface to the extent of the wells Appendix A in SEACOR's report contains well construction details Based on visual inspection and field instrumentation, 3 to 4 soil samples from each boring were submitted to a laboratory and analyzed for total petroleum hydrocarbons as gasoline (TPH-g) , and benzene, toluene, ethylbenzene, and xylenes (BTEX) One sample from each boring was also analyzed for total lead and EDB None of the soil samples were found to contain detectable concentrations of TPH- g, with the exception of those collected from W-8 (7, 900 ppm at 20 feet, 1 ,400 ppm at 45 feet, and 1, 700 ppm at 55 feet) Toluene (up to 120 ppm) , ethylbenzene (up to 110 ppm) , and xylenes (up to 700 ppm) were also indicated in the samples collected from W-8 Residual concentrations of BTEX and total lead were present in several samples collected from SB-7, W-7(SB-8) , and SB-9 , however, these did not appear to be present at concentrations of concern EDB was not indicated in any of the samples Table 1 in SEACOR's report summarizes analytical results and Appendix B contains laboratory reports Conclusions Based on the results of the site assessment, it appears that an additional investigation is warranted at this site Although the lateral extent of hydrocarbon-impacted soil has been defined to the northwest (by W-5 and SB-6) , west (by SB-4) , southwest (by SB-7 and W-7) , south (by W-6) , and east (by SB-9) , it has not been defined to the north and northeast of the former tank system The vertical extent of impacted soils appears to have been defined in all areas with the exception of the north and northeast portions of the site Future Site Activities At this time, a cost estimate has been received from SEACOR for an additional investigation to define the extent of hydrocarbon-impacted soils at the subject site Upon issuing a work order, SEACOR will prepare a workplan for the proposed additional activities I apologize for the delayed submittal of this report and hope that it has not inconvenienced you Should you have any additional questions regarding these matters, please do not hesitate to contact me at (206) 286-4495 If I am unavailable, Kevin Murphy may be able to answer any questions that you may have Sincerely, 4/ Anastasia E Duarte Environmental Toxicologist cc Ms Beth Thayer California Regional Water Quality Control Board aed\1un93\4049 115