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1 <br /> . Sample retrieval systems suitable for the valid where <br />' collection of volatile organic samples are positive — <br /> displacement bladder pumps, gear driven submersible n pi <br /> Pumps,syringe samplers and bailers(Barcelona, 1984, r — radius of monitoring well(feet) <br /> Nielsen, 1985) Field conditions and other constraints h — height of the water column (feet) <br />' will limit the choice of appropriate systems The [This may be determined by <br /> focus of concern must be to provide a valid sample for subtracting the depth to water from <br /> analysis, one which has been subjected to the least the total depth of the well as <br /> amount of turbulence possible measured from the same reference <br /> point] <br /> The following procedures should be followed cf = conversion factor (gal/ft') = 7 48 <br /> gal/ft' [In this equation, 7 48 gal/ft3 <br /> 1 Open the vial, set cap in a clean place, and is the necessary conversion factor] <br /> collect the sample during the middle of the <br /> cycle When collecting duplicates, collect Monitor well diameters are typically 2",31r,4",or 6" <br />' both samples at the same time Knowing the diameter of the monitor well, there are <br /> a number of standard conversion factors which can be <br /> 2 Fill the vial to just overflowing Do not rinse used to simplify the equation above <br /> the vial, nor excessively overflow it There <br />' should be a convex meniscus on the top of The volume, in gallons per linear foot, for various <br /> the vial standard monitor well diameters can be calculated as <br /> follows <br /> 3 Check that the cap has not been <br />' contaminated (splashed) and carefully cap v(gallft) ' nr2 {cf) [Equation 2] <br /> the vial Place the cap directly over the top <br /> and screw down firmly Do not overtighten <br />' and break the cap where <br /> 4 Invert the vial and tap gently Observe vial n = pi <br /> for at least ten(10)seconds If an air bubble r = radius of monitoring well (feet) <br /> appears,discard the sample and begin again cf = conversion factor(7 48 gallft') <br /> It is imperative that no entrapped air is in the <br /> sample vial For a 2"diameter well,the volume per linear foot can <br />' be calculated as follows <br /> 5 Immediately place the vial in the protective <br /> foam sleeve and place into the cooler, <br /> oriented so that it is lying on its side, not vol/linear ft nr2 (cf) [Equation 2] <br />' straight up 3 14 (1112 ft)2 7 48 gallft3 <br /> 0 1632 gallft <br /> 6 The holding time for VOAs is seven days <br /> Samples should be shipped or delivered to <br /> the laboratory daily so as not to exceed the Remember that if you have a 2" diameter well, you <br /> holding time Ensure that the samples must convert this to the radius in feet to be able to use <br /> remain at 4EC, but do not allow them to the equation <br /> freeze <br /> The conversion factors for the common size monitor <br /> 8.0 CALCULATIONS wells are as follows <br />' If it is necessary to calculate the volume of the well, Well diameter 2" 3" 4" 6" <br /> utilize the following equation Volume (gal/ft) 0 1632 0 3672 0 6528 1 4688 <br />' Well volume ' nr2h (cf) [Equation 1] If you utilize the conversion factors above, Equation <br /> 12 <br />