ARCHIVED REPORTS_XR0012715 - Laserfiche WebLink

Home Browse Search

A- M—Mb zsaRZ, P 0,27 ..._.�:N�-i' -..:...-..W_ ;rst -�� _..;,. _.: .�. ..,:az. - �t4r.� ?��". ,,. t�i �2 �.. �a-�. k� � �.gs._va._ �4�� "" w...�� . ii SAMPLING MU.-rlioD0L(rjj,.s U581) ON THIS PROJECT STANDARD RWQCD INTERFACK SAMPLE: ',he Lank removal rtampling followed the atandnrd protocol for obtaining interface fiftmplcn, Thena nntnplon (nil into the category of sample% which are known to be of primary concern to the Interested regulatory agonclon for determining if additional action will be required at a nits and the methodology has been clounly defined In State and RWQCB publications, oupplements, and pracentAtiona, Theno apecify both the acceptable depth and lateral situation of sample collection paints. in af,cordance with thane specifications, sample collt3ctlon in executed nit clone an Poncible to the conttr Lina (longitudinal axis) of the Lank and on a vertical axis with the fill pipe. A corresponding location its ahso found at the opposite end of the tank whenever standard interface unmpinu are being collected. Briefly, the method consists of digging up native coil from directly below the fill pipe and the corresponding opposite and of the tank and obtaining a sample from the backfill/native *oil Interface or a short distance below the Interface. In the case of tank& loan than 1,000 gallons in capacity, only one camplo from beneath the tank to required. A ahort diatnnce has been defined by Region 2 Board angineotrz as not greater than twenty-four Inches below the backfill/nntivu soil Interface and to generally taken to be one foot ba:ow the the backfill/native coil interface. Thin ooil In kiroughl up in the backhoe bucket. A shovel or trowel in used to cut away surface soil and backfill material which may have beer, included In the bucket, and the sample Is taken by pushing or driving a brass sample liner into the newly exposed soil from the designated depth and location. Additional clarifications by Region 2 Board engineers have indicated that when there Is an obvious difference In the relative contamination of soil brought up from the interface depth, than It in the retntively more contaminated soil that should be selected for Inclusion in the sample. ELECTIVE EXPLORATORY SAMPLP-S: This type or sampling employs the same sample collection and handling procedures an are used In standard RWQC13 Interface sumpling, but the coil Is typically obtained it a greater depth or from a position that is laterally offset from the interface location. STOCKPILE SURVEY MODIFIED 8AAQHD PROTOCOL' This sampling follows a survey pattern, but uses a modified BAAQMD protocol for sampling stockpiles of material that have bean newly removed from a tank pit excavation. Thin Protocol calls for a discrete sample container to be collected for every 12.5 cubic yards of material. The survey includes opposite sides of the stockpile. Strict observance of the BAAQMb protocol (for purponee of evaluating the 10VOIC.-.0f fuel vapor likely-to--be.-discharged-frnm-&-stock p114) - ealist far Inclusion of the surface material In the brass liner which Is driven Into the pile at a right angle (to the angle of ropos*) until the liner Is full. Unless specifically asked to follow the BAAQ,",ID protocol, our personnel rouLinely modify the procedure to exclude the surface soil and collect soil from a depth of eight to eighteen inches. While this prejudices the a-ample In the direction of yielding higher results than would a strict BAAQM D sample. It to more representative of the levels of fuel hydrocarbons Sampling Report 88306-M-3 Chevron 1918 SECTION FOURIpage 6