ARCHIVED REPORTS_XR0012715 - Laserfiche WebLink

Home Browse Search

r _ W, the relntively donee soil, the local Implementing agency Inspector decider not to have the interface Doli sampled and has tho backhoe dig• deopor to ace It the contaminntian diminishes to acceptable levels. This exploration naves the property owner the cost of running two namplen est that location, and annbldts it+e Inspector to ilrectly observe the condition of the deeper Nail. In both exnmplaa, different material In collected In lieu of a standard RWQCB Interface sample. Further, the material collected is substantially different from what would have been obtained by taking representative nail at the Board specified sampling location. Note that troth of these samples were taken at the direction of the local implementing agency lnspoctor who was present at the site and elnctad to select alternative sampling locations, Note too, that those alternative samples may provide more information about the site than standard hoard specified samples. However, as the LIA elected famples do not accurately reflect soil conditions at the sampling points specified by the RWQC13, the decision matting process may be hampered. Clearly there is no advantage in 'smiting the ability of they regulntor in the field to make prudent Judgementa. Likewise, regulatory personnel and consultants who will review the reports without benefit of having been present at the site need to know that the samples taken were not obtained nt the standard loca!tans. A simple resolution to these situations is a brief notation indicating [fiat the sampling was elective rather than in accordance E with a standard bop,rd specification. These notations appear in the third column of the TABLE OF SAMPLING LOCATIONS AND ANALYTICAL RESULTS. By referring to the notations In column three and four In the TABLE, any party reviewing the report should be able to determine if something other than Board standard samples were obtained, and when variant sampling was performed, clarify whether it was elected by the LIA inspector, elected by our field personnel, or the result of some physical condition at the site that made it Impossible to obtain material from the correct sampling location. SAMPLING METHODOLOGIES USED ON THIS PROJECT STANDARD RWQCB INTERPACH SAMPLE. The tank removal sampling followed the standard protocol for obtaining interface samples. These samples fall Into the category of samples which are known to be of primary concern to the interested regulatory agencies for determining if additional action Will be required at a site and the methodology has been closely defined in. State and i RWQCB publications, supplements, and presentations. These specify both the acceptable depth and lateral ultuation of sample collection points. In .+ accordance with these specifications, sample collection in executed an clord s as possible to 1 .d center line (longitudinal axis) of the tank and on a vertical axis with the fill pipe. A corresponding location is also found at the opposite end of the tank wh.ensver stand.ttrd._Interface-samples..-are._.being .----._-- -- -_------- Briefly, the method consists of digging up native soil from directly below the fill pipe and thq corresponding opposite end of the tank and obtaining s Sampling Report 88055-C-2 CHEVRON I9Ii3 paitie 8