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Dec A . 2003 6:24PM No -5270 P. 4 12/09/2883 11:17 218—M-1242 LEAK LOCATION SVS PAGE 03/84 AUied Waste -Pacific Division Page 3 December A, 2003 LLSI Project 425 M LEAK WcAT oN PROCEDURES The water puddle test for bare liners was used to rest the Izorwexd Unit 3 landfill, cell. This method detects electrical omtrent flowing through holes in the geo==bpQ0 liner that an f fled with water ®r other earth materials_ A water puddle test sensor was used to systematically spread the water over the top surface of the linen and a love voltage leak power supply wars used to energize the water with electrical ewmat. The low voltage leak power supply is conaccmd to an electrode placed in leak detection soil dr4nage layer located below they primary liner and the water puddle sensor head. When a hole in the liner is encountered warer will fill the hole or contact, the soils in the hole and cleatrical ewamt-will flow between the electrode located abovo and below the primmy liner. The change in electrical current is monitored using an LLSI leak that converts the increase in the current to an audible tome indication - The r s ..:k locationmethod electricalpaths ♦• am geomeI brane bridgingmaterial. Tbis electrical conduction path is provided by soil, water or other eleebical conductors geomembnnematerialand r k: • • -. t materials placedabove and below ithe geomembr=e. If the geomembrane is not in oompicte contact with the supporfing earth material$ then an electrical conductica path may not oxf st and leaks may not be detectP4 Tygicehy geometnbranes are covered with earth materWls such as water or s 1. The weight of these materials helps to hold the geomembraoe against the supporting sub -grade. In addition, the cover material ,keeps the geomernbrane from exposure to the sunt which helps to limit excessive wrinkling of the geomembr= material due to thermal expensiom However, it bare geomembrate does not have the advantage of the cover materials to help limit the wrinkling due to thermal expansion of the geomtembrane material. 13srs lifter water puddle: surveys am conducted when the liner matcrisl is m mploWy eontac&4 the wetderlying material, Therefore, bare liner surveys -area conducted during the cooler hours of the clay or very oarly morning hours when the liner material is tight and in complete contact with the supporting sub -grade.