ARCHIVED REPORTS_XR0011159 - Laserfiche WebLink

Home Browse Search

A � � aA S-I Step Discharge Test Results On April 1, 2004 the first step was performed at an extraction rate of approximately 0 5 gpm Initially, the pump was set approximately i foot above the bottom of the well However, sands and silts within the well inhibited pump operation The pump was reset (raised) to approximately 58 5 fbg to alleviate this problem This pumping rate was maintained for 109 minutes until the water table stabilized at 0 152 feet of drawdown A second step was performed at an extraction rate of approximately 10 gpm This pumping rate was maintained for 75 minutes until the water table stabilized at 1 541 feet of drawdown A third step was performed at an extraction rate of approximately 2 0 gpm This pumping rate was maintained for 6 minutes and produced 2 642 feet of drawdown The pump was then shut off and water level recovery was monitored The water level in well S-1 recovered to greater than 80% within three minutes of shutting off the pump S-1 Constant Rate Test Results: On April 2, Cambria elected to conduct the constant rate test at an extraction rate of approximately 0 75 gpm Well S-1 was pumped at this flow rate for approximately 5,410 minutes (88 69 hours) The maximum drawdown achieved in the pumping well was 1 695 feet The groundwater extraction set up for this test was designed to operate unmanned and Cambria personnel were not onsite during the entire duration of pumping Unfortunately there were two unscheduled shutdowns during the constant rate test There was no obvious cause for these shutdowns and it is likely our test equipment was tampered with by unauthorized personnel Groundwater Samples The initial groundwater sample collected from S-1 on April 1, 2004 contained no MTBE, 79,000 ppb TPHg, 1,400 ppb benzene, and 270 ppb 1,2-DCA The subsequent groundwater sample collected from S-1 on April 7,2004 contained no MTBE,76,000 ppb TPHg, 4,900 ppb benzene, and 880 ppb 1,2-DCA The subsequent groundwater sample collected from S-1 on April 8, 2004 contained no MTBE, 81,000 ppb TPHg, 3,500 ppb benzene, and 670 ppb 1,2-DCA The certified analytical report is provided as Appendix H Pump Test Analyses: During the S-1-85 step test, water level data in well S-3-84 and S4-83 fluctuated approximately 0 1 feet While this water level change appears to be related to the pumping in S-1-85, it was partially masked by the natural background fluctuation of the water table and overall was a low magnitude change The following factors did not allow the aquifer to be adequately stressed to induce a discernible drawdown in these observation wells 0797 8