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Messrs. Refer and Molen <br />M-1999-034 <br />February 1, 2005 <br />Page 4 <br />1.5 casing volumes, and every 0.5 casing volumes thereafter until stabilization." This would be <br />starting at approximately 6 minutes, then every 2 minutes until stabilization. Each time, record the <br />parameters (time, pH, conductivity, and temperature) in the logbook and on the field sheet. <br />Water Column Calculations <br />The well casing diameter is 8-5/8" per the-Well Construction Report, rather than 12". Please correct <br />all calculations to reflect this dimension. Using an 86-feet depth, as recorded on the Well <br />Construction Report, my calculations show <br />Radius <br />d 88in <br />r=-==4.3125 in <br />2 2 <br />Volume/ft of water in casing <br />h =nrZ =~r~4.3125in~Zl 12in)2(7.iftgal)=3.035ga1/ft <br />Using a static water level at 30 feet, h = 86 ft - 30 ft = 56 ft <br />Therefore, V = 13.035 ftl I(56 ft~=170 gal <br />Without-a-moraaccurate static -water-level-measurement, -to-purge a-minimum of three casing <br />volumes, 3V = 510 gal of water should be removed prior to sampling. <br />Pump Time <br />The Division will accept your proposal to rely upon the permitted pump rate as a conservative <br />estimate of the pump flow rate, and will not require that a flow meter be installed for taking the two <br />samples. <br />Based upon the corrected Water Column Calculations, <br />Three casing volumes, 3V=S10ga1. At 45 gpm, the minimum purge time is 11.3 minutes (use 12 <br />minutes). <br />Five casing volumes, SV = 850ga1. At 45 gpm, purge time is 19 minutes. <br />As noted in Item 2 below, pump/purge times need to be adjusted to account for pump surging, if <br />necessary for sample collection. <br />6 Sampling Method <br />1. The last four sections of the Protocol are errantly numbered "4, 5, 6, and 7." Please renumber as <br />6, 7, 8, and 9. <br />2. Step 2. Section 2, the Project Description, indicates that sampling from the -45 gpm pump <br />discharge will necessitate surging the pump. Step 2 of this section does not mention this practice <br />or elucidate how it will be accomplished, especially while simultaneously tracking purge times. <br />Please clarify, unless you and the Toppers agree on installation of a sampling port, in which case <br />that configuration should be included in this step. <br />