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4 The field parameters (pH, temperature, dissolved oxygen and specific conductance) were sometimes not allowed to reach equilibrium before the sample was collected. For well M-13 the pH and specific conductance (SC) measurements did not met the criteria for stabilization (±0.1 pH unit and ±10% in specific conductance). Three measurements of field parameters were taken: pH1=9.29, pH2=9.21, pH3=9.08; SC1=252pS, SC2=282NS, SC3=335pS. The last two pH measurements were within 0.1 pH unit if the measurement are rounded, but more importantly, there is a larger difference between the last two measurements than the first two, indicating that steady state has not been attained. The last two SC measurements were within 17%, not 10%, and again there was a larger difference between the last two SC measurements than the first two, indicating that the 5eld parameters had not yet stabilized. The method used to check stability of the dissolved oxygen (DO) and pH measurements was to turn the meter off, take a reading, turn the meter off again, take a reading. It would have been more accurate to watch the reading after turning the meter on again to observe whether or not the reading had stabilized. Groundwater wells M-9 and M-13 had at least three casing volumes purged from them before collection of the sample, while only approximately two casing volumes were purged from well M-12. However, the field parameters measurements from well M-12 were within the established stability criteria. Instruments are required to be calibrated at the beginning of each sampling day (TR-0006, pg. 16); in addition, the calibration should be checked after 3-5 samples are collected and after collection of a sample that differs significantly from the following sample (i.e., after collection of the process point samples but before collection of the groundwater well samples). Specific conductance measurements were not taken at the process point samples. TR-0006 is unclear about which 5eld measurements should be taken at the process points (except for temperature), but all field parameters, including dissolved oxygen and specific conductance can and should be taken. 2.2 Field Quality Control Samples According to TR-0006, the following QC samples should be collected: one field duplicate in 10 samples, one field blank in 20 samples, and one rinse blank in five (for groundwater and surface water samples) or 10 (for process points -- see pg. 32) samples. The rinse blank (taken after the collection pond sample) was prepared by washing the barrel filter with soapy water, rinsing with tap water, rinsing with DI water, filling the barrel filter with DI without a filter membrane and collecting the rinse blank. The filter membrane is an integral part of the filtration process and is not rinsed before filtration of a sample. RCG/Hagkr, Bailly, Inc.