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Flows at these levels in the past have been handled by the two existing pumps, with occasional use of a booster pump. It now appears as if the primary reason for LVSCS levels rising to near or above 24 inches is the gradual decrease in efficiency of Pump #2, which apparently was slowly declining since mid July of 2007. It is important to note that CC&V now concludes that the mechanical issues were the cause of this series of events, as opposed to our previous concern about the performance of the Phase IV primary liner or an anomalous precipitation or operational event. In this recent series of events, in addition to the diminished performance of Pump #2, the booster pump used to enhance the performance of Pump #1, failed sometime on August 4~h or Soh. This equipment failure resulted in the sump in-flow of approximately 59 gpm exceeding the pumped quantity of approximately 50 gpm, Subsequently, the transducers indicated sump levels of over 24". The followings steps were taken as soon as possible: 1. Alternate booster pumps were used to augment the pumping rate of both pumps (Sunday, August 5, 2007). 2. The 1 '/x" dischazge line for Pump #2 was replaced with a 2" line (Monday, August 6, 2007). 3. Pump #2 was replaced (Wednesday, August 8, 2007). As a result of these measures, the maximum pumping capacity was increased to over 66 gpm and the sump level declined to below the 24" level on August 9, 2007. With minimal driving head, each pump is now capable of approximately 31 gpm and over 33 gpm with a booster pump. This configuration will minimize the likelihood of a recurring elevated sump levels in the immediate future. Due to apparent inconsistencies in transducer readouts, Transducer #1 was replaced on the morning of August 15, 2007. Since this time, it appears as if Transducer #1 is functioning properly. An unsuccessful attempt to replace Transducer #2 was made on the afternoon of August 16, 2007. Since the pump must be pulled in order to replace the transducer, the decision was made to place the pump back into operation in order to minimize the time that the sump was over 24", and to address the Transducer #2 issue at a later date. The importance of the accuracy of Transducer #2 is secondary to the accuracy of Transducer #1 due to the fact that Pump #2 will quickly cavitate if left unchecked, thereby confirming a fluid level near zero in the vicinity of Pump #2. Due to sump design issues (size of pipe and points of inflow into the sump), there is a historical tendency for more flow to be experienced through Pump #1 than Pump #2.