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As the precautionary excavation is completed, the backhoe is used to dig up soil represen- tative of the material which remains in the bottom of the pit. The sample material is col- lected and handled according to the same procedures used with other backhoe assisted spm sampling except ilio depth at and duichplicates the tessoiis RCB standard interface sampling in all re- Stockpile Survey (Modified BAAQMD Protocol): This sampling follows a survey Pat- tern but uses a modified BAAQMD protocol for sampling stockpiles of material that have been newly removed from a card pit excavation. This protocol calls for a discrete s -M.ple container to be collected for every 12.5 cubic yards of material. The r regi(for ds opposite sides of the stockpile. Strict observance of the BAAQMD p purposes of evaluating the levels of fuel vapor likely to be discharged from a stockpile)calls fee inclusion of the surface material in the brass liner which is driven into the pile at a right angle (to the angle of repose) until the liner is full. Unless specifically asked to follow the BAAQMD protocol,our personnel routinely modify the procedure to exclude the surface soil and collect soil from a depth of eight to eighteen. inches. While this pix-judices the sample in the direction of yielding higher results than would a strict BAAQMD sample, it ci hydrocarbons present in the soil and is not .rkely is more representative of the levels of f u to mislead the client or contractor into o.`fhauling or backfilling with soil stockpiles that are relatively clean a[ the surface, but unacceptably contaminated through the remainder of their volume. Confirming Samples of Stockpiled Material: Samples were obtained of stockpiled material left on the site after the excavation of the main gasoline storage tanks. Sample collection points were laid out in a pattern designed to survey the entire area over which the material had been spread- Also, the SU—.Vey pattern was selected prior to digging into the subject material. At each sampling point in the pattern the surface soil was dug away and sample mattrial was obtained from a de'Dth or six or more inches below the aers[ed surface. This was done to avoid including the surface soil which was presumed to be thoroughly aerated and obtain soil that was not open to the air in order to confirm that the material was sufficiently aerated to require no further handling. Hand Driven Core Sampling: This is another tern for the sampling methodology that is often called undisturbed soil sarnplirg. This is the generally prefe-red sarr:piing me[hod for both geotechnical and environment2l investigations because the method captures a relatively undisturbed cylinder of soil which can be retained in its sealed brass liner, d rring transport to a laboratory for very praise ex=nination. Wrtleslter driven by a drill rig e. z much smaller hand operated slide hammtr, the principle attributes of tl:e methodology remain the same. Because of the tors of force which ca-n e*.erted by a drill rig: the sarnpiers,drill mx and hammers are.,necessarily,quite massivt. Apparatus used in hand augered borings is usual- ly much lighter and more s[ibjcct to :s e L.d breakage, Specialized hand tools that enable a person to drive samples consist of a s^nr,, ng sheer. (which contains the brass liners), light weight drill rod, :ald a small slide fiam;n::r. These ltand'operated drive saiiiplers samples in the same two inch diancetcr hi:Ls liners used in rrany drill rig samplers, b,:[ collect only a four or six inch long tor: ra•. er than twelvee to twenty four inches of soil commonly obtained by dril3ing apparan::;.