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I.f _ f GROUNDWATER MONITORING WELL SAMPLING AND PURGING PROTOCOL Prior to sampling the groundwater monitoring wells, the wells are open to the atmosphere for approximately one hour to allow for the groundwater.to adjust to the open barometric pressure. i The depth to groundwater is then measured in the well, followed by electrical conductivity, pH,and temperature readings of the groundwater. These parameters, along with the volume of the purged water (described below) and time, are recorded on the field sampling and purging i form. The volume of water in the monitoring well is calculated using the following equation: Feet of water in well x 0.163 for 2 inch diameter well = Volume water in gallons Feet of water in well x 0.653 for 4 inch diameter well = Volume water in gallons i Where the feet of water in well is calculated by subtracting the depth to groundwater from the total depth of the well. i i The volume of water to be removed is estimated by multiplying the volume of water in gallons I by three to four well volumes. This value will be recorded on the field form. i f The pH, temperature, and electrical conductivity will be monitored and recorded between each a well volume removed, and must be within 10% of the previous reading prior to sampling. The y groundwater level in the monitoring well is allowed to recover to 80% of the original depth } prior to sampling. 1 ,II l A minimum of four well volumes (where four volumes were available) were removed using a truck-mounted bailer prior to collecting the water sample. The removed water was placed in I steel storage barrels with bolt-on lids, which where retained on site. After the well had stabilized, water samples were collected using a disposable bailer with a check valve. j I