R2011-40 AUTHORIZING THE EXECUTION OF A WATER DISTRIBUTION SYSTEM LEAK DETECTION SURVEY AGREEMENT

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Large Pipe Alternative Survey Method Lake Crossings and Large Diameter Pressurized Pipe(14"diameter and larger) ADS will use a newer alternative technology in leak correlation that has specifically been developed for large diameter PVC and Concrete Water Mains as well as metallic mains.ADS would use a new leak detection technology from Echo-logics called the LeakFinderRT system. This system uses advanced leak noise correlation that is PC based that has dramatically improved performance on large diameter PVC and Concrete mains as well as metallic pipe. Master Meter Accuracy Testing To aid in the assessment of Unaccounted-for or Non-Revenue Water Loss,The City of Decatur requires accuracy tests of 5 Meters at the treatment plant and 6 large consumer meters. Each meter will be tested at working flow rate for 30 minutes duration. ADS shall complete accuracy tests of all requested master meters. These meters shall be tested in accordance with acceptable ISO 3966-2008Test and Measurement methods using calibrated instruments. The tests shall be conducted for a minimum of 30-minutes. Each meter will have two tests done at different flow rates to verify the results. The test instrument shall be certified and accepted as an accurate portable measuring device under the American Society of Mechanical Engineers— Power Test Code 18 and laboratory certified as accurate within±2%of the flow rate. Site Investigations Prior to accuracy testing,each meter site shall be physically inspected to verify the accessibility,safety conditions and appropriate appurtenances needed to complete the tests. Each site must have at a minimum either a full one-inch diameter corporation stop,an air release valve,or other access point such as a Mueller 1"Ground Key Corporation Valve H-9992 or an equivalent. If the tap is installed with a tapping saddle then the Ford Meter Box 1-1/4"Ford B11-455 Ball Valve with iron pipe inlet and outlet threads or an equivalent type would be acceptable. If the site investigations identify there is not an acceptable access point to the water main used for the accuracy testing then the consultant shall provide a photograph and diagram of the piping layout and indicate where an acceptable tapping point may be located or any other modifications would be needed to complete the tests. Accuracy Tests The true inside diameter of the measurement point must be made prior to the actual testing by actual measurement. The accuracy tests must be completed using an approved flow velocity measuring instrument and recording device. The instrument must be placed in series with the meter being tested under normal operating conditions. The instrument must be able to accurately measure point velocities of 0.5 feet per second or higher,with an accuracy of 2 percent or better. The instrument must have been in use and proven to be accurate in the water industry for at least five years. An accurate average velocity must be calculated by completing a velocity profile of the selected sites. The flow must be determined by multiplying the calculated average velocity by the true cross sectional area of the pipe as determined by measurement of the true inside diameter. The flow must be determined by multiplying the calculated average velocity by the true cross-sectional area of the pipe(Q=Va„g x Area). Detailed Scope of Work: 1. Conduct a site investigation in order to determine the locations for the gauging points necessary to test the meters. 2. Provide a detailed diagram and photograph of each site. A-3 Exhibits ADS Environmental Services