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order to determine the natural subsurface conditions,to be able to better recognize fill conditions, and to <br /> Prevent cross contamination For monitoring wells, a 2 x 2-foot square or 2-foot diameter circle is the <br /> minimum removal For soil borings and push-type samplers,the minimum pavement removal is 8-inches <br /> When pea gravel, sand, or other non-indigenous material is encountered,the drilling location will be <br /> abandoned unless the absence of subsurface facilities can be demonstrated and client approval to proceed is <br /> obtained If hole clearance activities are conducted prior to the actual day of drilling,the clearance holes <br /> are covered with plates and/or backfilled <br /> The minimum hole clearance depths are 4 feet below ground surface(bgs) outside the critical zone and 8 <br /> feet bgs within the critical zone and are conducted as follows <br /> • 0 to 4 bgs The area to be cleared exceeds the diameter of the largest tool to be advanced and is <br /> sufficiently large enough to allow for visual inspection of any obstructions encountered The <br /> first 1 to 2 feet is delineated by hand digging to remove the soil, then the delineated area is <br /> i <br /> probed to ensure that no obstructions exist anywhere near the potential path of the drill auger or <br /> I <br /> push-type sampler <br /> Probing is extended laterally as far as possible Hand augermg or post-hole digging then <br /> proceeds, but only to the depth that has been probed If subsurface characteristics prohibit <br /> effective probing, a hand auger is carefully advanced past the point of probing In this case, <br /> sufficient hand augermg or post-hole digging is performed to remove all the soil in the area to <br /> be delineated For soil borings <br /> located outside of the critical zone, an attempt should be made to probe an additional 4 feet <br /> • 4 to 8 bgs For the soil borings located inside the critical zone, probing and hand clearing an <br /> additional 4 feet is performed If probing is met with refusal, then trained personnel advance a <br /> hand auger without excessive force An alternate or additional subsurface clearance procedures <br /> may also be employed, as required by clients,permit conditions, and/or anticipated subsurface <br /> conditions(for example, near mayor utility corridors or in hard soils) Alternate clearance <br /> techniques may include performing a geophysical investigation or using an air knife or water <br /> knife If subsurface conditions prevent adequate subsurface clearance, the drilling <br /> operation is ceased until the client approves a procedure for proceeding in writing <br /> If any portion of the UST system is encountered, or if there is any possibility that it has been <br /> encountered, the work geaWs,and the client is notified immediately If there is reason to <br /> believe that the product sygtsm has been damaged,the emergency shut-off switch is activated <br /> Mmn\D\Environmental\PannarTexaco\Rcports\SAR1203 wpd <br />