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S E C 0 R � . 7-Eleven Store#32262 Extended Groundwater Pumping Test and Oxygen Injection Feasibility Study November 15, 2005 Page 4 constant rate test water levels were continuously logged in the pumping well and the two observation wells The calculated hydraulic conductivity during this test ranged from 0 0057 to 0 00036 centimeters per second On September 30, 2004, a report was submitted to the SJCEHD entitled, Results of Site Assessment, Remedial Feasibility Testing and Site Conceptual Model This report i summarized site activities and provided a guide for future assessment and remediation In a letter dated February 14, 2005, the SJCEHD approved the proposed extended groundwater pump test as outlined in the September 30, 2004 report Additionally, the SJCEHD requested an addendum work plan describing the pump test design as well as a work plan to further investigate the lateral and vertical extent of contamination On June 13, 2005, SECOR assumed ownership of the former Grant Line Gas and Food well MW-5(1n on behalf of 7-Eleven Inc MW-5(1) will be added to future monitoring and sampling events at the site On March 31, 2005, SECOR submitted a Work Plan for Additional Site Assessment and Interim Remediation Addendum to the SJCEHD The Work Plan was approved by letter dated May 3, 2005 The proposed 80 hour extended pump test and the Oxygen Injection Feasibility Test were conducted on September 12-16, 2005 and June 21, 2005 respectively EXTENDED GROUNDWATER PUMP TEST The purpose of this pumping test was to assess hydrogeologic conditions beneath the Site, and was conducted in accordance with the approved work plan All work was conducted under the supervision of a California-Certified Hydrogeologist Methodology Before beginning the step-drawdown and constant-discharge pumping tests, pressure transducers with built-in dataloggers were installed in pumping well EX-1 and observation wells S-1, MW-5, and MW-4 (Figure 2) on September 12, 2005 to monitor water levels before, during, and after aquifer testing A step-drawdown test was conducted on September 12, 2005 using a submersible pump in well EX-1 Before the start of the test, water levels in well EX-1, and the three observation wells (S-1, MW-5, and MW-4) were monitored and recorded Well EX-1 was pumped at slightly varying rates (steps) while monitoring changes In the water level in the pumping well The water levels and corresponding times were recorded during each step to allow for analysis of the drawdown attributed to each step, and to provide Information needed for the selection of an optimum pumping rate for the constant-discharge pumping test The optimum pumping rate is the highest pumping rate that would stress the aquifer without dewatering the well over the duration of the constant-discharge pumping test, which in this P case was approximately 80 hours ; 17-Elevenl7-11 stores1322621Reports132262 Pump Test and 02 Feasibility 11-10-05 doc SECOR Intemationa►Incorporated