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Ge0bg"I rechawsW Page 3 3 d Quarter 2001 Groundwater Monitoring Report Project No 507 2 November 6,2001 ' Gradients Slope and Bearing, and Table 2 shows the calculated vertical gradients The information used in the calculations is shown below Vertical gradient calculation formulas are as follows • Vertical correction for gradient [(gw gradient slope) x (distance) = vertical correction] ' • Vertical head [(head of deep well) - (head of shallow+ correction) µ vertical head] • Vertical gradient [(vertical head) / vertical distance) = vertical gradient] ' For the September 17, 2001, monitoring event, a vertical gradient was calculated for the MW-9/MW-109 pair The vertical gradient was negative (a downward direction) and twice the magnitude of the horizontal gradient of the water table 1.2 Groundwater Sampling Procedure On September 17, 2001, Don Light of Del-Tech mobilized to the site to conduct groundwater monitoring of the eleven existing monitoring wells Before sampling was attempted the wells were sounded for depth to water and then a clear disposable bailer was used to determine if floating product was present The wells were purged of at least three well volumes of stagnant water using a dedicated Waterra check-ball assembly and %2 inch tubing Purging continued until the temperature, conductivity, and pH of the groundwater stabilized (<10% variation between three readings), indicating that formation water representative of aquifer conditions was entering the wells These water quality parameters were measured at intervals of each well volume purged ' Once purging was complete, a water sample was collected from the Waterra tube Care was taken to minimize sample agitation Once the sample container was filled and capped, the ' bottle was inverted, tapped, and checked for headspace bubbles The sample container was identified and labeled with a unique designation, inserted into a foam holder and placed in an ice chest cooled to 40C for transport to the laboratory ' All non-disposable sampling using equipment g ui ment was decontaminated a hot water washer and detergent before and between uses Disposable gloves were used by the technician to µ ' collect all samples and were changed with each sample collection ' A chain of custody document, listing all samples collected, accompanied the samples from field to laboratory, thereby providing a means to track their movement and insure their integrity ' All water purged from each monitoring well and not used as a sample was placed in a 55 gallon DOT approved container These drums were properly labeled and will be stored on site until their proper disposition can be arranged