SITE INFORMATION AND CORRESPONDENCE

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'i Dennis Kim y 22633 Mount Edan Page 2 of 3 I analyses. The sample results were positive for diesel. Gasoline was also detected in the soil samples, but benzene was non-detect (ND). Approximately 2000 cubic yards of contaminated soil were excavated from beneath the USTs and,', stockpiled on November 27, 2002, and soil confirmation samples were collected from the final excavation. The soil sample results were positive for diesel and ''gasoline at the base of the excavation approximately 20 feet below ground surface (BGS). The above-referenced `site was placed in the EHD Local Oversight Program (LOP) in January 2003. On February 20, 2003, three monitoring wells (MW) were installed around the former UST area. On May 12, 2003, one Geoprobe (PB-20) was completed within 10 feet of the former USTs to 45 feet BSG. The soil samples collected ''and analyzed from 25 feet BGS and 30 feet BGS and were ND for diesel. The monitoring wells were sampled quarterly for one year and were ND for diesel 'and BTEX. EHD staff reviewed We September 13, 2004, Closure Summary Report (the Report) submitted by AGE on your behalf for the above referenced site. . AGE recommended site closure in the Report and stated in section 5.0 that a sensitive receptor survey is currently being completed for the site. EHD has not received the survey to date. Please submit the completed sensitive receptor survey to EHD for review. The Report includes positive soil and groundwater results from the Phase II investigation that may not be related to the unauthorized release from the two USTs. Other non-UST ',releases have occurred at this site and have resulted in pollution. The gasoline' contamination in the soil and groundwater may or may not be associated with releases from the two former redwood USTs used to store diesel or heating oil products. The maps and cross sections provided'to EHD to date do not clearly differentiate contaminants origination from non-UST sources from those that did originate from the former USTs. EHD cannot concur with the closure request at this time as there are several issues that remain open` • The three groundwater monitoring wells are not situated to monitor: groundwater in the immediate former UST area or in the down-gradient direction, one well is up-gradient, the other two are cross gradient. The cross-gradient we: and are 70 to 80 feet from the former UST pit and are 180 feet apart. This leaves a large gap in the monitoring system in the down-gradient direction through which contaminants may migrate. • It is not clear that the impacted soil encountered in borings B-5 and PB-2 are related to the' UST release as the borings are approximately 40 to 65 feet away from the former USTs, but had impacted soil as shallow as 5 feet BGS. • The site has apparently been utilized as an unregulated landfill as, evidenced by the occurrence of building debris, engine parts and empty°