|
' Supplemental Investigation Report,Problem Assessment Report and Work Plan
<br /> Cleanup and Abatement Order No 5-00-707 EAI Protect No 1232
<br /> In May 1987, JHK completed 10 soil borings (B6 through B14) and installed three wells (MW-
<br /> 4, MW-5 and MW-6) at the site (see Figure 4) The results of the soil testing are summarized
<br /> on Table 2, and ground water testing results on Table 4
<br /> Between September and December 1988, Kaprealian Engineering, Inc (KEI) completed soil
<br />' remediation work at the site by excavating approximately 6,000 cubic yards of soil from the
<br /> site (see Figure 4) The depth of the excavation in some areas was 53 feet bgs, t e , to ground
<br /> water The excavated soil was stockpiled on-site and at an off-site location After the soil was
<br /> excavated and stockpiled, composite soil samples from the stockpile were collected and tested
<br /> Based on these initial composite testing results, KEI concluded that
<br /> • 4,200 cubic yards of the soil excavated was clean and suitable for immediate reuse on-
<br /> site as backfill material
<br /> • 1,800 cubic yards of the soil required aeration to reduce the hydrocarbon concentrations
<br /> to acceptable levels, prior to reuse on-site as backfill material
<br /> Apparently, aeration was able to reduce the hydrocarbon concentrations to acceptable levels for
<br /> 1,600 of the 1,800 cubic yards aerated, and the other 200 cubic yards was reportedly
<br />' transported off-site for disposal (see KEI, 1988) Of the 6,000 cubic yards of soil excavated, it
<br /> appears 5,800 cubic yards was reused on-site as backfill matenal It should be noted that EAI
<br /> was unable to obtain a complete copy of the KEI report (see KEI, 1988), and that the report
<br /> EAI reviewed contained only the text, tables and figures Appendix B contains a copy of the
<br /> KEI report EAI reviewed
<br /> During soil remedial work, wells MW 1 and MW-7, and seven vapor extraction wells were
<br /> destroyed under permit
<br /> On August 25, 1989, the RWQCB issued a letter for the site confirming that the soil
<br /> contamination at the site has been adequately cleaned up, but, that the extent of ground water
<br /> impact has yet to be defined (see Appendix C)
<br /> Between 1988 and 1991, the property was redeveloped into an office building During this
<br /> time is appears that wells MW-3, MW-4, MW-5 and MW-9 were lost (see Figure 4)
<br /> In April 1992, monitoring wells W-1, W-2, MW-2, MW-8 and RW-1 were properly destroyed
<br /> An attempt to locate wells MW-3, MW-4, MW-5 and MW-9 using ground-penetrating radar,
<br /> was unsuccessful
<br /> During April and May 1992, KEI installed ground water monitoring wells MW-10, MW-11,
<br /> MW-12, MW-13, is1T,'�'-14 and M`,�'-15, and destroyed tivel l NIW-6 (see Figure 4) The results of
<br /> the soil testing are summarized on Table 2, and ground water testing results on Table 4
<br /> In November 1995, KEI installed wells MW-16 and MW-17 (see Figure 4) The results of the
<br /> soil testing are summarized-on Table 2, and ground water testing results on Table 4
<br /> BS 1232P IRW_WP -7-
<br />' ENVIRONMENTAL AUDIT, INC
<br />
|