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2015 URBAN WATER MANAGEMENT PLAN <br />consumption type listed above the associated validation score reflects utility policy for customer accounts, <br />frequency of meter testing and replacement, computer -based billing and transition to electronic metering <br />systems. <br />Water Losses are defined as the difference between the volume of water supplied and the volume of <br />authorized consumption. Water losses are further broken down into apparent and real losses. Apparent <br />losses include unauthorized consumption, customer meter inaccuracies and systematic data handling <br />errors. Default percentages were provided for the Audit by AW WA for unauthorized consumption and <br />systematic data handling error as this data is not often available. The corresponding default validation <br />score assigned is 5 out of 10. A discrete validation score was included for customer meter inaccuracies to <br />represent quality of meter testing records, testing procedures for meter accuracy, meter replacement <br />cycles, and inclusion of new meter technology. <br />System Data includes information about the City's physical distribution system and customer accounts. <br />The information included is: length of mains, number of active and inactive service connections, location <br />of customer meters in relation to the property line, and the average operating pressure of the system. The <br />number of service connections is automatically divided by the length of mains to find the service <br />connection density of the system. The calculated service connection density determines which <br />performance indicators best represent a water system's real loss performance. The validity scores in this <br />section relate to the water system's policies and procedures for calculating and documenting the required <br />system data, quality of records kept, integration with an electronic database including GIS and SCADA, <br />and how often this data is verified. <br />The final section is Cost Data and contains three important financial values related to system operation, <br />customer cost and water production. The total annual cost of operating the water system, customer retail <br />unit cost and the variable production cost per AF are included. The customer retail unit value is applied to <br />the apparent losses to determine lost revenue, while the variable production cost is typically applied to <br />real losses. In water systems with scarce water supplies, a case can be made for real losses to be valued <br />at the retail rate, as this volume of water could be sold to additional customers if it were not lost.] Validity <br />scores for these items consider how often audits of the financial data and supporting documents are <br />compiled and if third -party accounting professionals are part of the process. <br />Calculations based on the entered and sufficiently valid data produce a series of results that help the City <br />quantify the volume and financial impacts of water loss and facilitate comparison of the City's water loss <br />performance with that of other water systems who have also performed water loss audits using the <br />AWWA methodology. The City's Data Validity Score was 74 out of 100, with a total water loss volume of <br />677 AFY. The Non - Revenue Water volume represents 1.9 percent of the total water supplied by the City. <br />The value of non - revenue water is calculated to be $814,980 per year. <br />The Infrastructure Leakage Index (ILI) is a performance indicator developed from the ratio of Current <br />Annual Real Losses (CARL) to the Unavoidable Annual Real Losses (UARL). CARL was developed as <br />part of the workbook and explained as real losses above. UARL is developed on a per system basis with <br />an equation based on empirical data, developed by IWA that factors in the length of mains (including fire <br />hydrant laterals), number of service connections, average distance of customer service connection piping <br />between the curb stop and the customer meter and the total length of customer service piping, all <br />multiplied by average system pressure. The City received an ILI score of 0.15 which taken at face value is <br />a very high score and indicates that real losses are well managed. This value suggests that the City's real <br />arcadis.corn d I�b 2 -5 <br />