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Home Office Well Monitoring Report <br /> Tolerance Limit <br />Well U er Lower <br />1 5009.34 5007.27 <br />2 5017.31 5011.19 <br />3 5013.95 5007.84 <br />4 5014.69 5010.93 <br />5 5016.71 5012.86 <br />6 5020.29 5014.96 <br />7 5021.05 5015.71 <br />8 5023.88 5018.81 <br />9 5033.9 5031.05 <br />10 5035.35 5033.92 <br />11 5023.2 5017.85 <br />Precaution is necessary in the use of these values. It is important to check the data to make <br />sure that both the confidence and coverage are correct. The following table summarizes the <br />relationship between confidence, coverage and required baseline size. As the number of <br />datapoints increases, it is expected that the percent coverage will increase. <br />Confidence <br />~,/off Coverage <br />~,/off Required <br />Baseline <br />Size <br />50 50 3 <br />80 90 29 <br />90 80 18 <br />90 90 38 <br />90 95 77 <br />95 90 46 <br />95 95 93 <br />99 99 662 <br />The confidence interval should be near a value of 90% given the uncertainty of the system itself <br />and the desire for relatively strong assurance that the range of values is correct. A 90 percent <br />confidence interval corresponds to 4 data points outside of the tolerance limits. <br />Ten of the eleven wells that were monitored meet the coverage and confidence requirements <br />for the baseline size. The well that did not meet the requirements, Well 8, is located on the <br />Seaworth property. However, because it is only a monitoring well no mitigation will be required. <br />The owners of the property have not reported any problems. The pit has been mined to within <br />60 feet of this well. It is expected that the well will be mined through the next time that Lafarge <br />is working in this pit. <br />TST~ INC. CONSU LTIN6 ENGINEERS <br />Page 4 <br />