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U-Haul#709-50 Preliminary Site Conceptual Model Blaes Environmental December 15,2006 • 4 7 1 MW-6C Pump Test Results The MW-6C pump test lasted approximately 20 hours A total of approximately 2,493 gallons were purged from MW-6C during the 20 hour period which equates to a pumping rate of approximately 2 gallons per minute or 125 gallons per hour At periodic intervals during the pump test, Blaes Environmental monitored the water levels in extraction well MW-6C and surrounding monitor wells MW-6B, MW-9B, MW-2C, and MW-213 using a Heron groundwater level meter Static groundwater levels recorded during the MW-6C pump test are provided in Appendix N, Table 9 After approximately 20 hours of pumping, the maximum draw down (as measured with the Heron water level meter) in the extraction well (MW-6C) was measured at 1 18 feet (Figure 9) The maximum elevation change as measured by the Solimst level loggers equated to approximately 1 25 feet in extraction well MW-6C and approximately 0 23 feet in monitor well MW-613 (located approximately nine feet from MW-6C) At the conclusion of the pump test, the data loggers were removed from each well and subsequently connected to a laptop computer for data transfer The transferred data was analyzed using AQTESOLV software according to the Theis (1935) method for pump tests in unconfined aquifers Results of the data • analysis indicated a transmissivity of 0 OI615 ftz/minute and a storativity of 1 x 10 10 This equates to a hydraulic conductivity value of approximately 26 x 10' cm/s This hydraulic conductivity value corresponds with a soil type of silty sand, which relates (in general) to the soil types described in boring logs from drilling activities conducted at the site 4.7 2 MW-3C PumD Test Results The MW-3C pump test lasted approximately 6 5 hours A total of approximately 485 gallons were purged from MW-3C during the 6 5 hour period equating to a pumping rate of approximately 124 gallons per minute or 75 gallons per hour Technical data on aquifer conditions could not be derived from this pump test due to equipment malfunction During this test, the Solinst data loggers did not operate correctly and, as a result, the transmissivity and hydraulic conductivity values related to well MW-3C could not be calculated However, given the amount of data derived from the MW-6C pump test, further aquifer testing is not necessary 4.73 Pump Test Conclusion Given the results of the MW-6C pump test, it appears technically feasible to extract a large volume of • groundwater for a sustained period from the aquifer as a method of remedial treatment The hydraulic conductivity values calculated from the pump test correlate with the reported subsurface sediment Page 20