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volumes are removed prior to sampling, the lower pump rate will be used. The lower <br />pump rate is less than one-third the higher pump rate and between 3 and 9 well boring <br />volumes'will be removed. <br />Connect water piping to divert purge water away from the area around the <br />well. <br />2. Use the information in this section below to calculate the amount of water to <br />purge and the volume of water in the well. <br />3. Engage the pump. <br />4. Take an initial sample using one of the clean beakers and record the <br />parameters (pH, conductivity, temperature, and visual appearance) in the <br />logbook and the field data sheet. <br />5. Continue to allow the pump to pump a minimum of three boring volumes of <br />water from the well using the well purging information below. <br />6. Take at least three more samples using the beaker each time for the next <br />several minutes or as spread out over time depending on the pump rate and <br />purge volume. A minimum of three samples collected should be checked to <br />determine that the parameters have stabilized. Stabilization is determined by <br />parameter results that show the following: pH within 10%, temperature within <br />10%, and conductivity within 10% of the preceding values. If stabilization <br />does not occur continue to pump for enough time that a minimum of 5 boring <br />volumes are removed prior to sampling. <br />Water Column Calculations <br />A well casing size of 12 inches and a total well depth of 86 feet are listed on permit <br />number 32883. The static water level measured previously was 34.8 feet. Accounting for <br />the fluctuation of water levels in the well a higher water static water level of 30 feet is <br />used. The higher water level is used as an example for the calculations and to be a default <br />minimum of water to be removed if a water level measurement is not possible. <br />Calculation of well volume is as follows: <br />Well casing = 1 foot diameter = 0.5 foot radius <br />Formula for volume of cylinder = 7E r2 h <br />where h = 1 foot; r = 0.5 foot <br />Solving for volume of one foot in cylinder with 0.5 foot radius <br />Volume = 3.14 x (0.5ft)2 x lft <br />Volume in cubic feet per foot of cylinder = 0.785 <br />Converting to gallons using 7.48 gallons per cubic foot (7.48 x 0.785 = 5.872) <br />5