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• Page 2 of 11 <br /> Did I count correctly? You're contesting 13 wells out of 89? <br /> 1 can't remember, are you prepared for "a hole, one foot larger in diameter than <br /> the originally drilled hole, shall be excavated around the outside of the well <br /> casing to a depth of 3-feet below the ground surface, and the well casing shall <br /> then be cut off 6-inches above the bottom of this excavation and removed"? For <br /> an 8-inch borehole, that's a 20-inch hole and this is the requirement for pressure <br /> grouted wells (wells where the casing, filter pack, bentonite, and grout seal are <br /> left in place). <br /> I can't seem to find the actual work plan for the well destructions. Have you <br /> submitted it to me? IF not, please do. I'll continue to look for it now that you are <br /> working on this site again. <br /> Mike. <br /> From: Josh Ewert [mailto:ewert@geoconinc.com] <br /> Sent: Friday, November 04, 20114:27 PM <br /> To: Mike Infurna [EH] <br /> Subject: RE: 5400 and 5606 Pacific Avenue, Stockton - Well Destruction Information <br /> Good Afternoon Mike, <br /> Thank you for your comments on our proposal to destroy these 89 wells in Stockton. Now that finally <br /> have some time to spend on this]ob again, I will proceed accordingly. However, I'd like to make a case <br /> that some of the wells you proposed to be completely overdrilled should be allowed to be pressure <br /> grouted. <br /> ? VEW-16, VEW-19 and VEW-22—You state that these wells are to be drilled out based on their <br /> location within a line of estimated residual contamination and because VEW-19 and VEW-22 <br /> had soil vapor hits.The line that you reference is an isoconcentration contour for residual TPI-Ig <br /> in groundwater from AECOM's 9-22-2011 Figure 11. However, these wells do not and have <br /> never extended into groundwater making them not applicable to groundwater isocons. <br /> Additionally, the field data sheets presented in Attachment D of AECOM's Quarterly <br /> Remediation Status Report for the Fourth Quarter of 2009 show that each of these wells had PID <br /> readings of 0.0 immediately before the system was turned off for good on 12-28-09. This <br /> represents the most recent vapor data that we have for these wells and it shows that these <br /> wells are not in an area of pollution or contamination. <br /> ? MW-16 and MW-32—You state that these wells are within areas of contamination as shown on <br /> AECOM's 9-22-10 Figures 14 and 15.Are you willing to reconsider this due to the fact that these <br /> data points are estimated results?Or in the case of MW-32, the estimated result of 0.6 µg/I is <br /> below its ESL, MCL and WOO and thereby doesn't fit the county's definition of contamination or <br /> pollution? <br /> ? AS-20 and AS-21—You state that these wells are to be drilled out based on their 2008 soil data <br /> and because they are within the isoconcentration line shown in AECOM's 9-22-2010 Figure 11. <br /> The soil samples for AS-20 reported TPI-Ig concentrations at a depth of 50 to 70 feet with non- <br /> detect results at 80 and 90 feet while soil samples for AS-21 reported a TPI-Ig concentration at <br /> 11/7/2011 <br />