Laserfiche WebLink
S E C 0 R i <br /> . 7-Eleven Store#32262 <br /> Extended Groundwater Pumping Test and Oxygen Infection Feasibility Study <br /> November 15, 2005 <br /> Page 5 <br /> Based on the analysis of the step-drawdown test, the constant-discharge test was initiated <br /> on September 12, 2005 by pumping EX-1 at 0 8 gallons per minute (gpm) The objective of <br /> the test was to create hydraulic stress in the aquifer by pumping from well EX-1 at a <br /> constant pumping rate, while monitoring drawdown in wells S-1, MW-5, and MW-4 During <br /> the pumping test, water levels were continuously logged in the pumping well and the <br /> observation wells using a set time interval After approximately 280 minutes of continuous <br /> pumping in pumping well EX-1, with data collected at 1-minute-intervals, the data collection <br /> interval was changed to 15 minutes The data collection interval was set at 5 minutes for <br /> the observation wells The pumping rate fluctuated during the pumping test, and during a <br /> pumping rate increase to approximately 0 95 gpm the water level in well EX-1 dropped <br /> below the level of the transducer The pumping rate was then reset to 0 8 gpm and the <br /> water level began to rise Throughout the pumping test the pumping rate appeared to vary <br /> between 0 65 and 0 95 gpm The time-weighted average pumping rate, and that used for <br /> analysts of the pumping test data, was 0 72 gpm <br /> The pumping test flow rates were monitored using a totalizer to register water flow from the <br /> system to a holding tank At the conclusion of the constant-discharge pumping test, <br /> groundwater recovery data was monitored and recorded until the water level in well EX-1 <br /> recovered to at least 99 percent of its pre-pumping level The resulting drawdown data was <br /> analyzed to estimate the aquifer parameters of transmissivity (T) and hydraulic conductivity <br /> (K) <br /> Results of aquifer testing are discussed below A data plot of the drawdown in pumping <br /> well EX-1 is presented in Attachment B Field notes of the extended groundwater pumping <br /> test are in Attachment C <br /> t <br /> Step-Drawdown Pumping Test <br /> The step-drawdown test was conducted to determine an optimum pumping rate for well EX- <br /> 1 during the constant-discharge pumping test The transducers/dataloggers, installed in the <br /> observation wells to measure pre-test trends, were maintained at a 5-minute data-collection <br /> interval during the step-drawdown test Pumping rates were verified during the tests using <br /> a totalizer <br /> During the step-drawdown test pumping well EX-1 was pumping at rates varying between <br /> 0 8 gpm and 1 0 gpm Baseline groundwater level measurements were taken in the <br /> pumping well and observation wells before the start of the test During the course of the <br /> test, measurements were taken by transducers at the predetermined time interval After <br /> approximately 6 hours of pumping well EX-1, the extraction pump was shut off <br /> Groundwater level measurements continued to be taken from the pumping well and <br /> observation wells until well EX-1 was recharged Analysts of the drawdown data for these <br /> steps indicated that a pumping rate of approximately 0 8 gpm was the optimum pumping <br /> rate for an 80-hour constant-discharge pumping test <br /> 117-Elevenl7-11 Stores1322621Reports132262 Pump Test and 02 Feasibility 11-10-05 doc SECOR International Incorporated <br />