Laserfiche WebLink
20 December 2012 <br /> AGE-NC Project No. 01-0887 <br /> Page 3 of 5 <br /> REVISED FIELD PROCEDURES <br /> All field procedures will be overseen by an AGE representative under the supervision of <br /> a California Professional Geologist. The soil-vapor boring advancement and revised <br /> sampling procedures are described utilizing stainless steel canisters (Summa) and <br /> manifold assemblies. Leak testing, purge volume calculations, tracer gas application, <br /> purge, sampling and soil boring abandonment procedures are also described below. <br /> SOIL-VAPOR BORING ADVANCEMENT <br /> Probe borings will be advanced using a van-mounted Geoprobe®5400 direct-push probing <br /> unit equipped with 1-.25-inch probing rods. <br /> Clean and dry direct-push soil boring rods and a post-run tubing (PRT) system assembly <br /> will be prepared for advancement by installing new disposable O-rings on the PRT <br /> expendable point holder(the PRT adapter)and the disposable drive point. The boring rod <br /> with the PRT assembly will be advanced to the target sampling depth of 3 feet bsg for each <br /> soil-vapor sampling location, then the boring rod will be retracted approximately six inches. <br /> The PRT adaptor will then be connected to a disposable, single use, 1/4-inch Teflon <br /> tubing. The PRT adaptor and tubing will be inserted through the hollow boring rods down <br /> to the PRT assembly attached to the lead probe rod and seated to the adaptor into the top <br /> of the PRT probe assembly. <br /> Hydrated bentonite will be placed around the drive rod at ground surface to prevent <br /> ambient air intrusion. A minimum of 120 minutes equilibrium time will be allowed at each <br /> soil-vapor boring location prior to purging and sample collection. <br /> SOIL-VAPOR SAMPLE COLLECTION AND ANALYSIS <br /> One five-liter Summa canister will be utilized for purging and each soil-vapor sample will <br /> be collected in a one-liter Summa canister; during sampling one sample duplicate will be <br /> collected at a SJCEHD specified sampling location, which will be determined in the field. <br /> The sampling and purge canisters will be connected together with a dedicated and <br /> serialized sampling inlet manifold. The sampling inlet manifold will consist of a vapor-tight <br /> valve; a particulate filter; a calibrated flow restrictor, calibrated to 200 milliliters per minute <br /> (ml/min); a stainless steel tee-fitting;two vacuum gauges at either end of the flow controller <br /> and connections for both purge and sampling canisters(manifold assembly).The manifold <br /> assembly will be attached to the tubing from the direct-push soil probe rods. The purge <br /> Advanced GeoEnviro n mental,Inc. <br />