Laserfiche WebLink
('KLE/NFELOER <br /> erigMhopk Flgln S.ti.m[nf <br /> 2.3 BACKGROUND SOIL SAMPLING AND ANALYSIS <br /> RWQCB staff recommended that two background sample locations be used to assess <br /> the background soil quality. Two soil sample locations will be used to assess <br /> background soil conditions in areas where the former LTU had not operated. Soil <br /> samples will be collected at three depths from each location based on the use/depth of <br /> the former LTU (1 foot, 2 feet, and 3 feet) from the soil boring to analyze background <br /> conditions (six total). The boring locations are located outside of the former LTU area, <br /> approximately 100-200 feet west of the aqueduct service road near the southeast <br /> corner and eastern portion of the site (Plate 2). <br /> 2.4 SIMULPROBE GROUNDWATER SAMPLING, SURVEY, AND SAMPLING <br /> Drilling <br /> Using a C-57 licensed driller and standard hollow-stem auger (HAS) drilling techniques, <br /> Kleinfelder proposes to collect five groundwater samples at the former LTU to assess <br /> existing groundwater quality conditions and groundwater flow direction at the site (Plate <br /> 2). The drilling will be completed under the direct supervision of a California State <br /> licensed Engineer or Geologist. <br /> A total of five HSA borings will be advanced for the purpose of collecting soil and grab <br /> groundwater samples using SimulProbes in the vicinity of the former LTU (Plate 2). The <br /> SimulProbe grab groundwater and soil sampling technique was selected due to its <br /> updated technology over former grab groundwater sampling techniques. The probe has <br /> the advantage of being able to collect soil and groundwater samples in approximately the <br /> same zone, allowing correlation between soil and groundwater sampling results (there is <br /> both a soil and groundwater collection chamber in the probe). Additionally, discreet grab <br /> groundwater samples can be collected with a much lower probability of cross <br /> contamination. The groundwater samples are also much less turbid than typical grab <br /> samples. This is accomplished using a stainless steel sampling chamber equipped with <br /> 0-rings and by collecting samples using a down-hole application of nitrogen gas by <br /> positive displacement. Samples are collected at the surface from the center of the sample <br /> collection chamber (versus collection of samples from the bottom) using tubing, which <br /> greatly reduces turbidity in the sample. <br /> 128328/SAC14R0267 Page 5 of 11 July 12, 2013 <br /> copyright 2013 Kleinfelder Revision 2 -February 14,2014 <br />