Laserfiche WebLink
1 <br /> ARCADIS Brian Taylor, P.G. <br /> February 2,2009 <br /> 1 <br /> Passive versus Standard Sampling Technique Evaluation <br /> ARCADIS proposes to perform an evaluation of monitoring and sampling techniques <br /> (passive versus standard purge and sampling).The purpose of the evaluation is to <br /> investigate the feasibility of passive sampling techniques to collect groundwater <br /> samples during the monitoring and sampling program for the site.To facilitate the <br /> study ARCADIS will perform comparison sampling at the following monitoring wells: <br /> MW-5A, MW-12B, MW-28A, MW-29A, MW-31 A, MW-32A, MW-39UA, MW-65B, <br /> MW-67UA, and MW-69UA. ARCADIS will sample the monitoring wells using three <br /> passive sampling methods to compare data with the standard 3 well volume purge <br /> and sampling technique used currently during site-wide during quarterly monitoring <br /> and sampling.The three passive sampling techniques include: <br /> Grab Groundwater <br /> Snap Sampler' <br /> HydraSleeve® <br /> These no-purge groundwater sampling methods are discussed below. <br /> Snap Sampler T1" <br /> The Snap SamplerTm employs standard-sized 40-milliliter(mL)glass VOA vials with <br /> double-end openings. Specialty Teflon®end caps seal water within the Snap <br /> SamplerTM vial with an internal closure spring made of perfluoroalkoxy-(PFA <br /> Teflon®)coated stainless steel.To deploy the sampling device,the vial is placed <br /> inside the Snap SamplerT", and the end closure caps are attached to the sampler's <br /> trigger mechanism in an open position.The trigger cable is secured at the top of the <br /> well using a docking station.As many as four vials can be attached in series with one <br /> trigger cable.After a recommended minimum 72-hour equilibration period,the trigger <br /> is activated, "snapping"the sample vial(s)closed.The vial(s) are retrieved and <br /> remain closed prior to sample analysis. <br /> 1 <br /> Sampling Event <br /> Using the Snap SamplerT61 technology, ARCADIS will set four 40-mL glass VOA vials <br /> in series on a trigger cable(rig)at the mid-point of the well screen interval.The well <br /> and rig will be allowed the manufacturer's recommended 72-hour equilibration period <br /> I <br /> Page: <br /> 2/5 <br /> IWgOeubfiwmnl5xturcnbCR'fMAL1EMLM1W1611W OdwWIMWUMPYrM>P"V��htln'AMhipMmmhEon�m"�T`�10350.6x <br /> 1 <br />