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0 Appendix E <br />PERMEABILITY TEST PROCEDURES <br />Three in situ permeability tests were conducted at the San Joaquin <br />County Landfill Development Site. Two types of in situ tests were <br />conducted. The first type involved slug testing of a saturated <br />sandstone in Well G-1. The second type involved falling -head tests in <br />Permeameters P-2 and P-3 to determine the permeability in the unsatu- <br />rated zone immediately below proposed excavation depths. The results <br />of these tests, together with laboratory permeability results, are <br />presented in Table E-1. <br />Slug testing is used to determine values of hydraulic conductivity for <br />a water -bearing zone. Hydraulic conductivity is a measure of the <br />water -transmitting characteristics of a material. Values obtained <br />from a slug test represent a "point measurement" and provide an <br />evaluation of aquifer permeability in the vicinity of the borehole. <br />Slug testing involves inserting into or removing from a well a "slug" <br />or object of known volume to create an instantaneous change of water <br />level. At this site a PVC slug, 11 feet in length and 2.25 inches in <br />diameter, was used. The slug was quickly lowered into the well, and <br />the changes in water level were measured using a pressure transducer <br />while the level returned to static (falling -head test). After the <br />water level stabilized, the slug was removed, and levels were again <br />monitored as they returned to the original static water level (rising - <br />head test). <br />Both falling- and rising -head tests were conducted at Well G-1. The <br />well is completed in the uppermost water -bearing zone, which is <br />considered to be unconfined. EMCON slug tests are analyzed using a <br />computer program that employs the method developed by Bouwer and Rice <br />(1976). This method of analysis assumes that the aquifer is uncon- <br />fined, homogenous, isotropic, and infinite in areal extent and that <br />