ARCHIVED REPORTS_XR0007433 - Laserfiche WebLink

Home Browse Search

VVZI INC 49 53 Groundwater Sampling Groundwater sampling at the site was conducted by McLaren, WaterWork, California Environmental Engineers and Contractors (CEECON), CalTest Analytical Laboratories and WZI personnel from 1989 to 1997 Appendix II is a standardized water sampling protocol that was reportedly used by each of the consultants in accordance with established water sampling guidelines published by the Regional Board (1992) Groundwater surface elevation measurements and water samples were collected from monitoring wells MW-1 to --10 and from the main and standby water supply wells located onsite All water samples were analyzed for TPH-G and VOA analysis by Modified EPA Test Method 8015 and EPA Test Method 602, respectively Monitoring wells MW-1, -3 and -6, which showed the presence of elevated concentrations of VOAs, were also sampled for ethylene dibromide (EPA Test Method 504) and organic lead (tetraethyl lead) The primary water supply well and the backup water supply well at the site were sampled for VOCs (EPA Test Methods 601 and 602), ethylene dibromide (EDB) and total volatile hydrocarbons (Modified EPA Test Method 8015 (modified)) Monitoring wells were allowed to equilibrate following construction for a period of not less than 12 hours prior to initial groundwater sampling Prior to sampling, the top-of-casing elevation for each well was surveyed relative to an assumed datum of 20 feet MSL, as derived from the United States Geological Survey topographic map of the Lodi North Quadrangle, California The depth to water from the top of the well casing to the groundwater surface in each well bore was measured These values were then used to determine the groundwater surface gradient • Before sampling, monitoring wells MW-1 through -8 were purged by pumping approximately 55 gallons of water from each well Monitoring wells MW-9 and -10 were bailed dry and 19150011 005 18