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Ms Margaret Lagono Page 3 of 4 1 Table 2 Oxygenates and additive concentrations are summarized in Table 3 Attachment B contains laboratory reports and chain of custody documentation ' Groundwater Sampling Summary and Discussion ' • Water levels rose this quarter Well screens in monitoring wells MW 1 through MW 12 and vapor wells VW I,VW3 and VW4 remain submerged ' • TPHg was not detected in wells MW6, MW7,MW9 and MW 11 and benzene was not detected in wells MW9 and MW 1 I • Despite increases in some wells this quarter, overall petroleum hydrocarbon concentrations in the monitoring and vapor extraction wells appear to be generally stable to decreasing ' • High levels of MTBE persist in the wells located on the southern portion of the property New well MW 14 was reported to contain a concentration of 24,000 ppb, the highest level ever detected in any well on the site MTBE is not present in wells located within the area affected by the onsite gasoline 1 release • EDB and 1,2-DCA appears to be associated with the onsite release VAPOR EXTRACTION SYSTEM ACTIVITIES ' VES Operation The soil vapor extraction system was not operated during the first quarter of 2001 pending the results of ' confirmation borings and direction from PHS/EHD regarding further operation of the system Confirmation borings sampled during the first quarter indicate that no significant vadose soil contamination remains These results will be presented in a separate report currently in preparation 1 RECOMMENDATIONS VES Operation Based on the analytical results of the confirmation soil borings we recommend removal of the thermox system, and destruction of selected vapor extraction wells Specific recommendations will be presented in the pending report ' Quarterly Groundwater Monitoring and Sampling We will perform groundwater monitoring and sampling for the first quarter in May 2001 PHS/EHD will be notified 48 hours prior to conducting the quarterly fieldwork mek+wnA1Q1N2001