65B - PROPOSED WATER AND SEWER RATE ADJ

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City of Santa Ana, CA Figure B - 1: Example Risk Heat Map Graph Relating PoF and CoF Scores. 10 C, v 3 8 LL 7 W 0 6 v V v 5 3 v 4 c v 0 3 F] 1 Probability of Failure 1 2 3 4 5 6 7 8 9 10 GENERAL ASSUMPTIONS AND OBSERVATIONS During the source data review, condition assessment and planning analysis, various assumptions were made to permit further evaluation. Many of these were necessary due to limitations in the existing data such as missing or conflicting pipe attributes, limited inspection data, or similar constraints. for example, the timing of pipeline lining is often unclear. The association of water break data to the correct asset was also not precise. Although good engineering judgment was used in the analysis of historic pipeline condition data, an unknown level of inaccuracy exists. Due to the limited quantity and quality of source data, further investigation is recommended before making specific rehabilitation or replacement decisions. The following list includes many of the general assumptions and observations made during the planning assessment on the water outside -plant network system. Additional comments are included in specific sections of this document. • Only water mains were considered in this assessment. The condition of pump stations, service laterals, reservoirs, etc. were not addressed. • Pipeline Type = "PRIV" or "ABAN" were omitted from the water analysis. • Pipe segments with zero length were omitted from the analysis. • The timing of pipeline lining is often unclear. Therefore, it was assumed that any inspection data referred to the pipe conditions prior to lining. Once lined, the pipe was assumed to have been "fixed" and currently be in very good structure condition. • Based on the GIS source data provided, it appears that zero water or sewer pipe was installed in 2010; even though 47 water main breaks occurred that year. BLACK & VEATCH I Appendix B'. Water CIP Prlerltizanon Process 65B -91 79