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Message Page 1 of 2 <br /> Jeff Wong [EH] <br /> To: Angelo.Franchitto@ch2m.com <br /> Subject: RE: Re drilling well MW-10 at PG&E's Lathrop <br /> Angelo and Bob: <br /> Your proposal to overdrill the 20-foot well is acceptable. The previous destruction permit SR34951 issued to <br /> is still valid. However, if you've decided to use a different C-57 driller, a new permit application plus $60 fee must <br /> be submitted. <br /> I've checked with our Accounting Office and you still have$186 in the account; therefore advance payment is not <br /> necessary. You will be billed for any additional time over this amount. <br /> regards, <br /> Jeff <br /> -----Original Message----- <br /> From: Angelo.Franchitto@ch2m.com [ma ilto:Angelo.Franchitto@ch2m.com] <br /> Sent: Tuesday, February 03, 2004 4:34 PM <br /> To: Jeff Wong [EH] <br /> Cc: Diane.Sarmiento@ch2m.com; Bob.Noyes@ch2m.com <br /> Subject: Re drilling well MW-10 at PG&E's Lathrop station <br /> Jeff, <br /> This is to follow up on our telephone discussion this afternoon regarding well MW-10 at PG&E's Lathrop <br /> station which was abandoned last August. <br /> MW-10 was located outside of the station about 3-4 feet east of the fence.At the time,we did not have <br /> permission from the property owner to access the well from outside of PG&E's station fence line, and were <br /> therefore forced to abandon this well from within the station fence. Our only option to abandon the well was <br /> to remove the entire length of PVC casing, which we did, and tremie grout the well. Upon removing the <br /> casing, the sand filter pack of the well sloughed into the borehole and we were only able to place our <br /> tremie pipe about 10 feet below ground surface (bgs). As discussed with you at the time, we made the <br /> grout thinner than usual to aid in grouting the sand below the 10-foot level, and tremie grouted the borehole <br /> from 10-feet to about 4-feet bgs. <br /> At the time, you indicated that because we could not grout this well from the base (20-feet bgs)we needed <br /> to over excavate the well during our remedial excavations, and that you wished to be present when this <br /> was done. Because it is extremely difficult to over drill an already grouted borehole with standard <br /> environmental drilling equipment, we propose to over drill the well to the installation depth of 20-feet bgs <br /> with a large-diameter, solid-flight post-hole type drilling rig, and backfill the borehole with grout. The well <br /> is located within our proposed excavation perimeter, in an area that is to be excavated to about 10-12 <br /> feet bgs. <br /> We understand that you are satisfied with this method and that you will let us use the existing well <br /> abandonment permit that was approved last August. We also understand that you will inform us of the <br /> payment required for you to come out and inspect the over drilling procedure once you get an estimate of <br /> the time/cost from your accounting department less any credit remaining in our account. <br /> Our project manager, Bob Noyes, and our onsite construction superintendent, Cecil Gore, will schedule the <br /> drilling and contact you at least 48 hours prior so you can observe the work. At your request, the over <br /> drilling and regrouting of this borehole will take place at least 24 hours prior to excavating soil near the well. <br /> Currently, the excavation work is scheduled to commence in approximately 2 weeks time. <br /> regards <br /> 2/4/2004 <br />