Laserfiche WebLink
Jim Pinasco <br /> January 4, 1995 <br /> Page 3 <br /> ground water samples will be collected using the dedicated <br /> bladder pumps. However, based on the November 30, 1994 meeting, <br /> current and future ground water sampling protocol does not use <br /> bailers. Because bailers will no longer be used for ground water <br /> sampling at DDRW Tracy, including this sampling method in the <br /> study provides data that will no longer be useful, therefore, <br /> needlessly increases the cost of the overflow rate sampling <br /> study. <br /> Recommendations <br /> It is recommended that the low-flow rate sampling study not <br /> include sampling with bailers for two reasons: (1) bailers will <br /> no longer be used for ground water sampling at DDRW Tracy; and <br /> (2) bailers are not the preferred sampling method for collection <br /> of ground water samples to be analyzed for volatile organic <br /> compounds. Therefore, the cost of analyzing samples collected <br /> using a bailer does not appear to justify including this in the <br /> study, and the Report should be revised to delete bailer <br /> sampling. <br /> ■ <br /> 3 . Sequence of Sampling <br /> The Report discusses conducting the low-flow rate sampling <br /> study over an extended period of time to allow for conventional <br /> sampling with a bailer, installation of dedicated sampling <br /> equipment (bladder pumps) , low-volume purging and low-flow rate <br /> sampling, and finally standard purging (three saturated well <br /> volumes) and sampling with dedicated bladder pumps. To reduce <br /> the number of variables in the sampling study, the ground water <br /> samples should be collected as close together in time as <br /> possible. Because sampling with a bailer is not recommended (see <br /> comment 1) , low-volume purging and low-flow rate sampling <br /> followed by standard purging and sample collection with the <br /> dedicated bladder pump can be performed sequentially with minimal <br /> time elapsing between sampling with the two different purging <br /> methods. <br /> Recommendations <br /> It is recommended that low-volume purging and low-flow rate <br /> sampling be followed as rapidly as practical by standard purging <br /> and sample collection with the dedicated bladder pump. A <br /> MS.mk <br /> MS4.015/5 <br />