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Page 2 of 2 <br /> at approximately 25' bgs and check for the presence of free product. The results of free product <br /> measurements conducted on September 26, 2011 indicated no free product in MW-5, and about a foot of <br /> product in MW-2. These results, along with the soil testing results from MW-5, indicate that we may be <br /> dealing with a submerged plume in the area of the old waste oil tank. Review of DWR water level data <br /> (attached) for well 01N06E14Q003M located in McKinley Park about 0.5 miles north of the site indicates <br /> that the water table elevation in 1990 was about -30 feet msl when the waste oil tanks were taken out of <br /> service. This elevation is about 18 feet lower than the current elevation of about-12 feet msl. A release <br /> of heavy product to the 1990 water table may have become trapped and submerged due to the rising <br /> water table. <br /> In accordance with our Corrective Action Plan Feasibility Study, a free product recovery test was to be <br /> performed on the new well MW-5. Based on the preliminary data from September 2011, no free product <br /> is encountered on the current water table surface in MW-5. In lieu of the recovery test recommended in <br /> the CAPFS, we plan on checking for free product in well MW-5 on a weekly basis for about one month to <br /> confirm either the presence or absence of free product in well MW-5. Free product will continue to be <br /> removed from MW-2 as before. <br /> In addition to the above, a slug test on MW-4 is planned per the CAPFS to provide hydraulic conductivity <br /> data needed to perform the Monitored Natural Attenuation analysis. The slug test is currently schedule <br /> to occur in early December. After the slug test and free product monitoring is complete, we will issue a <br /> report summarizing the findings of this work as well as the well installation work. <br /> As far as the preparation of a work plan to perform batch extraction of groundwater at MW-4, we want to <br /> evaluate the most recent groundwater analytical data from September 2011 first. Based on the February <br /> 2011 data, there was a significant order of magnitude reduction in both TPH-Gasoline and benzene in <br /> groundwater samples from MW-4. Should this trend continue, groundwater extraction may not be <br /> warranted. <br /> Please contact us if you have any questions. <br /> Joseph Krohn, PG <br /> Taber Consultants <br /> 707 365 5843 <br /> ikrohn@taberconsultants.com <br /> 1/10/2012 <br />