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<br /> Stantec
<br /> The content of this email is the confidential property of Stantec and should not be copied, modified, retransmitted, or used for any purpose
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<br /> Please consider the environment before priming this email.
<br /> From: Vicki McCartney [EH] [mailto:vmccartney@sjcehd.com]
<br /> Sent: Friday, May 02, 2014 12: 58 PM
<br /> To: Westhoff, Brian
<br /> Cc: Gabriel Gonzalez [EH]
<br /> Subject: RE: Arco 2130, Stockton Regulatory Response
<br /> Good afternoon Brian ,
<br /> Gabe Gonzalez, the new case worker for ARCO Station No. 2130 at 7906 North EI Dorado Street in
<br /> Stockton, and I visited this site on Wednesday, April 30, 2014. 1 have also discussed with Adrienne
<br /> Ellsaesser, Program Coordinator, Stanteds proposals for this site submitted in Well Destruction Work
<br /> Plan.
<br /> The following is a list of issues concerning the work plan :
<br /> 1 . Under Well Destruction Activities on page 2, second paragraph, AS-2 and AS-3 are listed twice
<br /> among the fifteen wells that Stantec proposes to require a variance.
<br /> 2. On page 2 of the work plan , Stantec proposes to place a mushroom cap at one foot below surface
<br /> grade ((bsg) when pressure grouting MW-5, MW-6, MW-13, MW-20 , AS-2, AS-3, VW-3, VW-6, VW-
<br /> 8, VW-10, VW-11 and MW-3A/B; however, on page 3 of the work plan Stantec proposes to air knife
<br /> to three feet bsg and cut off the casing at three feet bsg . There is no mention of a mushroom cap.
<br /> Stantec does state that "Given the risks associated with the subsurface structures at MW-6, AS-2 ,
<br /> AS-3, VW-3, VW-6 and VW-11 , Stantec recommends air knifing to approximately one ft bgs, and
<br /> each well casing will be cut at approximately one ft bgs. The borehole locations will be backfilled
<br /> and resurfaced with appropriate materials to match the existing grade. " Again there is no mention of
<br /> a mushroom cap.
<br /> If you propose to pressure grout some of the wells, you must include forming a mushroom cap. Cutting off
<br /> the casing at one foot bsg will not be deep enough to form a one-foot mushroom cap, with grout six inches
<br /> below and six inches above the cut-off casing. I suggest that you propose hand digging to two feet bsg , cut
<br /> off the casing at 1 .5 feet bsg , form a mushroom cap from two to one foot bsg , and finish off the last foot bsg
<br /> with appropriate materials to match the existing grade.
<br /> I am waiting to hear from Nuel Henderson as to whether MW-14 , MW-19 and MW-21 should be pressure
<br /> grouted or over-drilled . Since diesel was found in soil when installing these three wells, I believe that these
<br /> wells should be over-drilled . Once Nuel has commented about these three wells, I will let you know.
<br /> In conclusion, our agency will allow variances to pressure grout wells in or near the USTs, product lines,
<br /> electrical lines and near the Healy tank. However, the work plan in its current version will not be acceptable
<br /> and must be revised .
<br /> Please contact me if you have any questions concerning this email.
<br /> Thank you Brian.
<br /> Vicki McCartney, Senior REHS
<br /> San Joaquin County
<br /> Environmental Health Department
<br /> 1868 East Hazelton Avenue
<br /> Stockton , California 95205
<br /> Phone: (209) 468-9852
<br /> Email: vmccartnevosicehd .com
<br /> 5/ 14/2014
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