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68 <br />SEWER RATE STUDY 1 City of Santa Ana, CA <br />Figure B- 1: Example Risk Heat Map Graph Relating PoF and CoF Scores <br />Probability of Failure <br />1 2 3 4 5 6 7 8 9 10 <br />10 <br />9 <br />Q) <br />8 <br />LL 7 <br />w <br />0 <br />v 6 <br />V <br />v 5 <br />7 <br />v 4 <br />c <br />V O 3 <br />2 <br />1 <br />10 <br />20 1 30 40 517 1 "' I —_ 1 80 90 <br />( 100 <br />Replace / Redesign <br />9 <br />18 27 36 4! Strategy 77 <br />11 Economic Based ) 48 5 72 <br />90 <br />8 <br />80 <br />Replacement Strategy e <br />7 <br />14 Li to 15 4 SLOt 56 63 <br />70 <br />6 <br />12 <br />18 <br />24 <br />3 <br />SS 42 4R [;a 60 <br />predictive <br />5 <br />10 <br />15 <br />e <br />J`'��e <br />d� <br />30 35 Monitoring SO <br />4 <br />8 <br />teas <br />20 <br />24 1 28 Strategy 40 <br />12 <br />15 <br />Condition 24 27 30 <br />Monitoring <br />Runto i <br />8 <br />10 <br />Strategy 16 18 20 <br />Failure <br />4 <br />5 <br />6 7 <br />8 <br />9 <br />10 <br />GENERAL ASSUMPTIONS AND OBSERVATIONS <br />During the source data review, condition assessment and planning analysis, various assumptions were <br />made to permit further evaluation. Many of these were necessary due to limitations in the existing data <br />such as missing or conflicting pipe attributes, limited inspection data, or similar constraints. For <br />example, the timing of pipeline lining is often unclear. The association of water break data to the correct <br />asset was also not precise. Although good engineering judgment was used in the analysis of historic <br />pipeline condition data, an unknown level of inaccuracy exists. Due to the limited quantity and quality of <br />source data, further investigation is recommended before making specific rehabilitation or replacement <br />decisions. <br />The following list includes many of the general assumptions and observations made during the planning <br />assessment on the sewer outside -plant network system. Additional comments are included in specific <br />sections of this document. <br />• Only sewer mains were considered in this assessment. The condition of manholes, service <br />laterals, lift stations, etc. were not addressed. <br />• Pipeline Type = "PRIV" or "ABAN" were omitted from the sewer analysis. <br />• Pipe segments with zero length were omitted from the analysis. <br />• The timing of pipeline lining is often unclear. Therefore, it was assumed that any CCTV <br />inspection data referred to the pipe conditions prior to lining. Once lined, the pipe was assumed <br />to have been "fixed" and currently be in very good structure condition. <br />• Based on the GIS source data provided, it appears that zero water or sewer pipe was installed in <br />2010; even though 47 water main breaks occurred that year. <br />65B -227 <br />NOVEMBER 2014 <br />