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Figure ES - 1: Installed Mains by Decade <br />:oo <br />a 700 <br />LL <br />0 <br />v <br />600 <br />c <br />500 <br />0 <br />r <br />c <br />400 <br />v <br />m 300 <br />m <br />Y <br />N <br />5 200 <br />N <br />C <br />100 <br />0 <br />SEWER RATE STUDY I City of Santa Ana, CA <br />In order to produce an R &R program, Black & Veatch conducted a high -level condition assessment <br />review using City - provided Geographic Information System (GIS) data and available condition reports for <br />the water system. Black & Veatch evaluated the available data and held two workshops with <br />engineering and maintenance staff to develop weighting factors for the asset assessment. Combining <br />the condition reports and workshop results, Black & Veatch determined the Probability of Failure (PoF) <br />and the Consequence of Failure (CoF). The PoF is a measurement of the likelihood that a particular asset <br />will fail. The PoF score is arrived at by weighing factors such as the physical properties of the asset <br />(material, age, etc.), the conditions of the surrounding environment (soil conditions, earthquake faults, <br />etc.), and operational history. The CoF assesses the relative importance of each pipe in terms of delivery <br />levels of service, economics, and health and safety. Criteria weighed in determining a CoF score include, <br />but are not limited to, pipe size, critical customer impacts, and proximity to major roads. <br />The product of the PoF and the CoF results in the Business Risk Exposure (BRE) — the higher the BRE <br />score, the higherthe likelihood that the asset requires attention. <br />Without detailed condition assessment information, Black & Veatch cannot quantify the absolute risk of <br />failure; instead, the analysis conducted herein provides a picture of the relative risk of failure. In other <br />words, the analysis indicates which assets are more likely to fail in relation to other system assets. On its <br />own, the BRE score is not sufficient to develop a Capital Improvement Program (CIP). Consequently, <br />Black & Veatch developed R &R strategies reflecting how public agencies tend to conduct work — <br />grouping projects by area. Based on criticality criteria (PoF and CoF), Black & Veatch developed a list of <br />projects to address immediate system needs over the next 5 years. <br />As shown in Figure ES 2 and explained in more detail in Appendices A through D, the City's sewer system <br />has no extremely critical condition (red zone — highest risk of failure) lines. There is 0.1 miles ($0.1 <br />million) in highly critical condition (gold zone), 3.8 miles ($3.7 million) that are critical (yellow zone), and <br />10 <br />65B -169 <br />NOVEMBER 2014 <br />