ARCHIVED REPORTS XR0000213 - Laserfiche WebLink

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Based on the groundwater data, the inferred groundwater flow direction beneath the site is to the east (Figure 2) with an average hydraulic gradient of 0 003 meter per meter (0 003 foot per foot) 3 2 GROUNDWATER SAMPLING Groundwater samples were collected from fourteen monitoring and/or vapor extraction wells Prior to the collection of groundwater samples, the monitoring wells were purged of a minimum of three well volumes of water and until pH, conductivity, and temperature stabilized The wells were allowed to recover to at least 80 percent of their original static groundwater levels prior to sampling Wells VW-1 and MW-26 were sampled on August 3, 1998 prior to their abandonment The following are procedures were implemented for well monitoring, well purging, and water sampling 1 All equipment was washed prior to entering the well with an Alconox solution, followed by two tap water rinses and a deionized water rinse 2 Prior to purging the wells, depth-to-water was measured using an Solinst groundwater interface probe to an accuracy of approximately 0 01 foot The measurements were made to the top of the well casing on the north side 3 Monitoring wells at the site were prepared for sampling by purging the well of approximately three well volumes of water using a polyvinyl chloride (PVC) bailer 4 Water sin samples were collected with a le-use Teflon bailer after the well had P g been purged and water in the well had equilibrated to approximately 80 percent of the static water level or two hours after well purging, whichever occurred first The water collected was immediately decanted into laboratory-supplied vials and bottles The containers were overfilled, capped, labeled, and placed in a chilled cooler prior to delivery to the laboratory for analysis 5 Chain-of-custody procedures, including chain-of-custody forms, were used to document water sample handling and transport from collection to delivery to the laboratory for analyses 6 Groundwater samples were delivered to the State-certified hazardous waste laboratory within approximately 48-hours of collection 7 Purged water was contained in a DOT approved 55-gallon drum The dram was labeled with the contents, date, well number, client name, and project number 2 iF Transfer�ReporriCALTRANS1CafiyO97471977%gm398fin