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City of San Leandro Sewer System Management Plan Volume I A rating schedule for line damage covering the range from light to medium to severe damage is applied to each condition found. The sum of these individual damage ratings divided by the length of the line televised provides a damage rating per foot value defined as the Damage. Severity Index (DSI) for the line segment. DSI = Sum of individual damage ratings =Damage Rating / Ft. Length of line segment televised The DSI value of the line segment defines its relative damage ranking among any of the line segments having undergone a condition assessment. The DSI value is calculated and included as an item in the line segment record when the VUCA data is added to the database. A DSI query of the CMMS database provides a listing of the VUCA investigated line segments ordered from worst to least. This listing provides knowledge of the most significantly damaged lines of system and those most likely in need of immediate repair. Engineering investigation of the Condition Assessment data for these lines and funding concerns will define the plan of rehabilitation improvements for the upcoming year. The DSI value is the key to selecting only needed and necessary improvements to the system to avoid overflows and return the collection system to safe and functional service to the community. DSI values are also used to reschedule the next CCTV/condition assessment work for the less than significantly damaged line segments. Overall, the condition assessment completed during the last five years has found the system is in good to moderate condition. Of the pipes included in the assessment, approximately 35% were in good condition, 63% in moderate condition, and 2% in poor condition. In pipe reaches with defects, the most numerous structural defects were sags, followed by offset joints and longitudinal cracks. The City also has an annual CIP project for pipe rehabilitation, asdiscussed in Section 8. In order to continue to effectively identify and prioritize sewer rehabilitation and repair needs, the City plans to apply the same rating system to future CCTV inspection results. The City will use the system to facilitate the development of the scope for the annual sewer repair CIP projects. Manhole Inspections Inspections conducted for manholes involve a visual assessment of the overall manhole condition and observed deficiencies that could result in UI. As part of the focused and cyclic cleaning programs, City maintenance staff visually inspect manholes for corrosion, debris or damage around the base, cracks or holes, and condition of manhole steps. Ratings applied to manhole investigations use a condition codes for each of the manhole structure components including the rim and lid, chimney/cone, bench and channel. Each component is rated as poor, fair, or good condition as a gross determination of construction adequacy of the structure and its component parts. ~~~e ~ ~.s