Laserfiche WebLink
ST I <br /> n <br /> 8720033A-COT-5 `fVoodward•Ciyde+Consuitants <br /> soils encountered are presented in Appendix A. Soil samples were recovered <br /> by advancing the augers to a point immediately above the sarple interval <br /> and then driving a modified California Sampler with clean brass liner tubes <br /> through the hollow auger stem. The sampler was then winched out of the <br /> auger string and the sample tubes removed and sealed with aluminum foil and <br /> plastic end caps. Generally the second of the three sample tubes in each <br /> interval was retained for chemical analysis. The soil samples were <br /> delivered to the WCC environmental laboratory under Chain-of-Custcdy <br /> control. After removal of soil subsamples for analysis by WCC, the soil <br /> samples were transmitted under Chain-of-Custody control to California <br /> Anlaytical Laboratory for organic lead analysis. The completed Chain <br /> Custody forms are included in Appendix B. Soil samples were visually <br /> inspected in the field for stains and checked for odors. An HNU <br /> photoionization detector was 'used to check soil samples for organic <br /> vapors. Selected soil samples were sealed in ajar, shaken, and the <br /> photoionizer probe used to check the headspace for organic vapors. Many <br /> soil samples were found to have a distinct hydrocarbon odor or yielded a <br /> non-zero reading when tested with a photoionization detector. <br /> Monitoring Wells <br /> Groundwater monitoring wells were constructed in the soil borings at the <br /> completion of drilling. The groundwater wells were constructed with 4-inch <br /> diameter PVC pipe, with 20 foot lengths of well screen perforated with <br /> .020-inch slots extending from 28.5 to 30 feet to 48.5 to 50 feet blow <br /> the wall of the <br /> grade. The annular space between the slotted pipe and <br /> boring was backfilled with No. 3 Monterey sand to approximately 3 to 4 feet <br /> above the perforated section. A 1 to 2-foot bentonite plug was placed <br /> above the sand pack. The annular space from the top of the bentonite plug <br /> to the ground surface was filled with neat cement grout. The wells were <br /> completed with locking boxes at the surface. <br />