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Mike Infurna <br /> From: Robert Hammond [rhammond@ameinc.net] <br /> Sent: Monday, March 11, 2002 11:29 AM <br /> To: Mike Infurna <br /> Subject: Re: Well destruction requirements <br /> Mike: <br /> Thank you for your input on well destruction criteria. I will write the work <br /> plan for over bore destruction of BC-12 and RW-1. I will look into historic <br /> soil data for BC-1 before proposing an abandonment method in that case. You <br /> asked for the most recent chloroform data in wells subject to destruction: <br /> BC-12 was last sampled in Jan 102, with chloroform reported at 16 ug/L. RW-1 is <br /> not routinely sampled, but chloroform at 21 ug/L was reported in a sample from a <br /> nearby monitoring well (BC-7) , also in Jan 102. BC-1 is a dry well and not <br /> sampled. Regulatory cleanup levels mentioned by the RWQCB are 1.1 ug/L <br /> chloroform, but our client has not agreed to this low level. <br /> Mike Infurna wrote: <br /> > get me the most current groundwater concentration data for the chloroform <br /> > impacted wells subject to destruction. ANy soil data in this area that is <br /> > NON-DETECT would support pressure grout methods. . .It's been our experience <br /> > that pressure grout is far from an exact science and over-excavations around <br /> > and thru monitoring wells destroyed by this method have revealed substantial <br /> > pockets of filter pack NOT impacted by the pressured grout and have provided <br /> > vertical conduits for contaminated soils to migrate to the groundwater. . .IF <br /> > no soil contamination exists in areas very close (if not the actual soil <br /> > sampling from the installation of the well)then pressure grouting may be <br /> > considered. Actual groundwater DETECTABLE levels of the contaminant <br /> > typically will require OVER-BORING for well destructions. . .irregardless of <br /> > MCLs. . . <br /> > Unless you are NON-DETECT at acceptable regulatory levels, plan on o/bore. <br /> > as for the private parcel, the rig installed it, and it should have been <br /> > clear from the start that a rig would take it out. A signed access <br /> > agreement for private parcels is required for permit issuance. EHD will <br /> > need a copy prior to issuance. <br /> > As a foot note, some shallow wells with a short grout may be PULLED up <br /> > slightly to allow the bottom cap to be 'popped' off. If this is possible, <br /> > then once the cap is off, grout can be added thru the casing. As the casing <br /> > is pulled up, the grout stays and mixes with the filter pack providing an <br /> > acceptable mixture (sand slurry) . The 'contents' of the well are removed, <br /> > the well is destroyed and NO large rig and no over bore may be necessary. <br /> > It's a shot in the dark sometimes, but when it works, it eliminates a lot of <br /> > work. This probably won't work for the 68 and 80 footers. . . .but you may <br /> > save substantially on the shallow one. <br /> > -----Original Message----- <br /> • From: Robert Hammond [mailto:rhammond(Dameinc.net] <br /> > Sent: Friday, March 08, 2002 4:36 PM <br /> > To: minfurna@sjcehd.com <br /> > Subject: Well destruction requirements <br /> > Mike: <br /> > Thanks for researching the monitoring well BC-8 destruction date the <br /> > other day. Now, I have a new question: <br /> > I will be applying for a permit to destroy wells BC-1 (2", td = 28.5 ft <br /> > bgs) , BC-12 (211, td = 68 ft bgs) , and Rw-1(811, td = 80 ft bgs) at the <br /> > same Tracy site in the near future. Costs for abandonment are <br /> > considerably less if a pressure grout method is acceptable vs. over <br /> 1 <br />