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<br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />the Test was slight "frosting" (erosion) on the leading edge <br />of the turbine blades, No other damage was observed, but it <br />is anticipated further damage would be associated with <br />long-term flows of less than 350 cfs, <br /> <br />During the Test, the minimal variation (low flow) in power <br />production seemed to have a significant effect on noise <br />(caused by cavitation) from the unit. The noise from the <br />turbine runner sounded like gravel passing through the unit, <br />and there appears to be a direct correlation with the wicket <br />gate adjustment on the unit and the noted noise, As the <br />wicket gates are closed to reduce the passing flows to the <br />generating unit, the noise in the generating unit appears <br />to increase, <br /> <br />Attachment D contains the City of Farmington's impact <br />analysis of the Test. Their assumption is that although no <br />significant damage was detected during the Test, damage is <br />likely to occur at 250 cfs over a longer period of operation, <br />The seriousness of this expected damage is yet to be <br />determined and will require a longer period of low flow <br />to assess, <br /> <br />Method <br /> <br />Before the Test, the unit was opened, inspected, and photo- <br />graphed in detail by the City of Fannington to note existing <br />conditions. The unit was also inspected immediately after <br />the Test to document any damage, During the Test, the <br />generating unit output averaged 6 MW, ranging from 5,7 to <br />6.4 MW per day. Calculations based on the unit's per- <br />formance curves indicated the load should be 5,8 MW per <br />day, <br /> <br />Summer Low Flow Test Report - April 2002 <br /> <br />-21- <br />C(600 <br />