65B - PROPOSED WATER AND SEWER RATE ADJ

Home Browse Search

WAFER RAI"E Si JOYS City of Santa Ana, CA Figure ES - 2: Number of Breaks per Mile of Pipe by Installed Decade and Material mAc ■CI it YCYL ■DI ■PVC HSTL HUNK AC= Asbestos Concrete CYL = Pre-stressed Concrete STL — Steel Cl = Cast Iron DI = Ductile Iron LINK = Unknown CMLC = Cement Mortar -Lined & Coated Steel PVC = Poly Vinyl Chloride In order to produce an R &R program, Black & Veatch conducted a high -level asset condition review using City - provided Geographic Information System (GIS) data and available condition reports for the water system. Black & Veatch evaluated the available data and held two workshops with engineering and maintenance staff to develop weighting factors for the asset assessment. Combining the condition reports and workshop results, Black & Veatch determined the Probability of Failure (PoF) and the Consequence of Failure (CoF). The PoF is a measurement of the likelihood that a particular asset will fail. The PoF score is arrived at by weighing factors such as the physical properties of the asset (material, age, etc.), the conditions of the surrounding environment (soil conditions, earthquake faults, etc.), and operational history. The CoF assesses the relative importance of each pipe in terms of delivery levels of service, economics, and health and safety. Criteria weighed in determining a CoF score include, but are not limited to, pipe size, critical customer impacts, and proximity to major roads. The product of the PoF and the CoF results in the Business Risk Exposure (BRE) — the higher the BRE score, the higher the likelihood that the asset requires attention. Without detailed condition assessment information, Black & Veatch cannot quantify the absolute risk of failure; instead, the analysis conducted herein provides a picture of the relative risk of failure. In other words, the analysis indicates which assets are more likely to fail in relation to other system assets. On its own, the BRE score is not sufficient to develop a Capital Improvement Program (CIP). Consequently, Black & Veatch developed R &R strategies reflecting how public agencies tend to conduct work — 4 65B -16 NOVEMBER 2014