Laserfiche WebLink
Ambient sewer effluent samples were collected through manholes by lowering a collection vial <br /> into the middle of the effluent stream. Flush sewer effluent samples were collected through the <br /> same manholes by injecting potable water in an upstream direction and then collecting a sample <br /> as the surge of injected water flowed back down stream past the manhole (NERI, 1996). <br /> Sewer effluent sampling results reportedly indicated the presence of 1,1, 1-TCA(8,980 gg/1), <br /> 1, 1-DCE (177 µg/1), 1,1-DCA (14.7 µg/1), and TCE (5.1µg/1) in the sewer system downstream <br /> of the LNC site and other facilities during 1993. Subsequent sewer sampling in 1995 did not <br /> detect any VOCs in the vicinity of the LNC site. <br /> 4.5 Discrete Depth Groundwater Sampling <br /> The RWQCB, DTSC, and City of Lodi have conducted discrete-depth groundwater sampling <br /> throughout the City of Lodi between 1989 and 1995 to assess the horizontal and vertical <br /> distribution of VOCs within the groundwater. During the 1993 investigation, twenty nine (29) <br /> HydroPunch discrete-depth groundwater samples were collected from 16 soil boring locations <br /> throughout the City of Lodi. Of these, 11 water samples were collected from six of the <br /> HydroPunch borings located within the northern portion of the City of Lodi, including one on <br /> the LNC site (URS, 1994). <br /> The discrete-depth groundwater samples were typically collected at first encountered <br /> groundwater at about 50 to 60 feet bgs. At five of the locations, multiple depths were sampled <br /> up to 121 feet bgs. The discrete-depth groundwater sample analyses results reportedly indicated <br /> the presence of various solvents including 1,1, 1-TCA and its degradation products and PCE and <br /> its degradation products. <br /> During 1996 WZI investigated the LNC site with exploratory soil borings. Three continuous <br /> core soil borings were advanced into the first encountered groundwater zone beneath the LNC <br /> site and adjacent property owned by Ackel (WZI, 1996). Three shallow, discrete-depth <br /> M ain\D:AEnvironmentaI\LN CV\10152007.wpd 19 <br />