Laserfiche WebLink
# Comment Response to Comment <br /> Furthermore,the entire vinyl chloride plume at IAS-14 is not <br /> vertically constrained. <br /> Recommended Actions: Central Valley Water Board staff <br /> recommend the Port add at least three additional grab <br /> groundwater samples to the north (e.g.near W-204), east(e.g. <br /> near W-156), and west(e.g. W-143)around the plume at site <br /> IAS-14 to fully characterize all dimensions of the plume <br /> geometry.Additional deeper samples are also necessary within <br /> the currently defined and modeled plume to define the <br /> maximum vertical extent. <br /> 9 Issues: According to Table 6 of the 9 November 2018 Third See response to DTSC General Comment 4. <br /> Quarter 2018 Groundwater Monitoring Results, groundwater <br /> monitoring well W-167 exceed(ed)California Maximum <br /> Contaminant Levels(MCLs) for Gross Alpha and Gross Beta in <br /> the Southern Landfill area. However,the duplicate sample <br /> collected at W-167 in Q3 2018 was non-detect for Gross Alpha <br /> and Gross Beta.The extent of this radionuclide plume is thus <br /> now unknown, and radionuclide analyses are not proposed in <br /> the Investigation for grab groundwater samples for this <br /> location. <br /> Recommended Actions: Central Valley Water Board staff <br /> request the Port add radionuclide analysis to wells that will be <br /> sampled near W-167 in the Investigation. This would include <br /> the grab groundwater sample GGW-17 and any additional wells <br /> or grab groundwater samples added in response to Comment 7 <br /> above.Additional groundwater samples should again be <br /> collected from W-167 because of the discrepancy between the <br /> main sample and duplicate sample observed in the Q3 2018 <br /> sampling event for radionuclides. <br /> 9 08.03.2019 <br />