Beyond Risk: A Community Return on Investment Approach to Pipe Rehabilitation

American water resource agencies are increasingly turning to risk analysis to prioritize replacement and rehabilitation (R&R) activities, especially for distribution and collection system piping. Risk is commonly evaluated using a two-dimensional matrix, and pipes scoring highest in both dimensions (failure likelihood and failure consequence) are scheduled for attention first. This approach is an improvement over traditional methods but still has two shortcomings: It ignores the cost of the rehabilitation as compared with its benefits, and it does not help utilities identify those activities that are worth undertaking from a community value point of view — and those that are not. A number of agencies, including the Orange County Sanitation District (OCSD), are developing more comprehensive approaches to address both of these shortcomings and to identify which R&R activities are truly in the public's interest.