ARCHIVED REPORTS XR0009905 - Laserfiche WebLink

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Results of Groundwater Pumping Tests - 152 East 11 th Street, Tracy Page 9 found that the area was blanketed in fog and the air temperature was very cold To wait for improved weather conditions, the start of testing was delayed until 12 25PM, when the fog had cleared and the temperature had risen Despite the improvement, the air remained noticeably hazy - a condition which is indicative of an elevated atmospheric moisture content - but it was decided to proceed with a test before further delay precluded any testing during the remainder of that day At that time, a pumping test was started using the same equipment and procedures as have been described for the testing performed on December 28th , except that the pressure transducers were used to measure drawdown in both the pumped and observation wells The pump discharge rate was measured to be 9 0 GPM Outputs from the pressure transducers were instantaneously, and essentially simultaneously, recorded by the electronic data logger Following the start of pumping, these recordings were initially separated by intervals of 0 5 sec and later at logarithmically-increasingly, longer intervals according to the standard procedure used to record groundwater pumping test data Approximately 4 5 min after the start of pumping, the pump froze, discharge from the pumped well stopped and the groundwater level rose After waiting for both the pumped well and the observation well to recover and for the weather to further improve, a second test was attempted In this case, with some intermittent hesitation of the pump, steady pumping was sustained for more than 1 5 hrs , toward the end of which period the air temperature was falling steadily and the air was becoming increasingly hazy Then at about 4 11 PM, 98 minutes after pumping was restarted, the pump froze for a second time and, thereafter, could not be operated again for more than a few minutes before becoming frozen At that point, it was determined that worsening weather conditions would prevent any further sustained pumping from the well that day Therefore, because sufficient data had been obtained from the testing conducted on December 28th to make the necessary calculations of hydrogeologic parameters and a field review of the data recorded from the early period of the sustained pumping that had been achieved over the immediately preceding hours indicated that sufficient early-time date had in fact been obtained, no further attempts to pump from Well NAV 6 were made on January 18th However, recording of the pressure transducers' output was continued until 6 45PM, at which time the water level in both the recovery and observation wells had returned to essentially the same elevations as before testing was begun For purposes of record, the drawdown date gathered during the pumping tests performed on January 18th 1994 are documented in Appendix B