WORK PLANS - Laserfiche WebLink

Home Browse Search

17 February 2012 AGE-NC Project No. 03-1100 Page 3of4 results of the soil-vapor sampling and analysis. Conclusions and recommendations will also be included in the reports,'if applicable. The report will be`'in a format acceptable to the CVRWQCB guidelines, and will be reviewed and signed by a California Professional Geologist. 3.0. FIELD PROCEDURES All field procedures will be`overseen by an AGE representative under the supervision of a California Professional Geologist. Procedures for soil boring'advancement, soil-vapor sample collection, equipment decontamination and boring abandonment are presented below. 3.1. SOIL-VAPOR PROBE BORING ADVANCEMENT Each probe boring will be advanced to a maximum depth of five feet bsg_using a truck mounted AMS Powerpr be direct-push drilling rig equipped with 1.25inch, stainless steel, hollow probing rods The Powerprobe rods are advanced using a hydraulic hammer to drive the attached soil-vapor sampling tool to specified depths. Proposed boring locations are presented in Figure 2. - 3.2. SOIL-VAPOR SAMPLING Soil-vapor samples will be obtained at depths of approximately four to five feet bsg in each boring.,Samples will be collected using a Geoprobe soil-vapor sampling assembly. An expendable vapor point will be placed into a poinf"holder at the bottom of an assembly of 1.25-inch diameter hollow drive rods. The assembly will then be advanced to the specified depth and retracted approximately six to twelve inches in order to disengage the expendable point and expose a.column of strata from which soil-vapor can-be extracted. A single use, '/4-inch diameter disposable polyethylene tubing is-then attached to a tubing adapter equipped with'an O-ring to ensure a vacuum-tight seal. The adapter assembly is then lowered through the center of the Geoprobe hollow drive rods to the specified depth and secured by threading into the expendable vapor-point holder. A stabilization time of . _- 20 minutes will follow boring placement. A diagram of the soil vapor samplingtis- presented p is r pr se ented in Figure 3. s Above ground, the surface around the soil vapor sampler will be sealed with a bentonite sealant.to prevent ambient air intrusion. The end of the polyethylene tubing is attached by a two-way inlet port to a Tedlar bag placed inside an SKC Vac=U-Chamber (lung box) Advanced GeoEnviroomental,Inc.