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PART 3 3.1 WN 3.3 peak leak signal plus noise signal to background noise ratio R=(S+N)BN for each of the recorded data lines. The measured leak signals must have characteristics of a leak. Wild data points that deviate from the theoretical leak signals shall not be used to determine R. 5. The two farthest lateral lines of data with an R value greater than 3.0 shall be noted. The average of the lateral distance from the leak for these two lines is defined to be the leak detection distance for the artificial leak 6. If unfavorable site conditions prevent obtaining an R ratio of 3.0 from being obtained, the leak location equipment shall be demonstrated to be able to detect an artificial leak from a smaller distance no less than 1 foot to verify that the leak location equipment is operational. LEAK LOCATION SURVEY PREPARATION A. The EARTHWORK CONTRACTOR shall uniformly wet the bare geomembrane with an equivalent of 0.2 -inches of water prior to the leak location survey B. The EARTHWORK CONTRACTOR shall uniformly wet the granular drainage material to field capacity. C. The GEOSYNTHETICS CONTRACTOR shall terminate the edge of geomembrane so that it is electrically isolated from earth ground. This requires leaving the geomembrane bare around a narrow strip around the perimeter of the geomembrane test area. is D. The CONTRACTOR'S shall assist the Leak Location Contractor with other preparations that may be necessary to meet the performance requirements of the leak location survey. LEAK SURVEY A. The leak location data shall be taken: 1. With a uniform measurement density of greater than one measurement every 10 square feet, or 2. On survey lines spaced no further apart than twice the leak detection distance determined for the artificial leak as discussed in Part 2. The measurement electrode spacing shall be no less than that used for the performance demonstration. The spacing between measurements shall be no more than that used for the performance demonstration. B. The data shall be recorded, plotted, and analyzed for leak signals. The positions of these leak signals shall be located and the leaks excavated. The leaks shall be repaired in accordance with the specified requirements for HDPE geomembrane. C. Following the repair, the leak location survey shall be repeated on the two closest survey lines for a distance extending 20 feet before and beyond the leak. If another leak signal is detected, the entire repair and resurvey process shall be repeated until no additional leaks are detected. REPORTING Forward Landfill WMU FU -13 ATTACHMENT A 2 LEAK LOCATION TESTING