Gaps of Decision Support Models for Pipeline Renewal and Recommendations for Improvement

As part of the U.S. Environmental Protection Agency (EPA)'s Aging Water Infrastructure Research Program, one key area of research pursued, in collaboration with wastewater and water utilities, was a study of the current approaches available for making rehabilitation versus replacement decisions. The purpose of this study was to: (1) identify the current methodologies and decision support models being used for determining how to rehabilitate or replace underground utilities; (2) identify the critical gaps of these current models through comparison with case history data collected from utilities; and (3) assess the feasibility of substantially improving upon existing approaches. This paper identifies the decision support models and methodologies that have been proposed/used in the US for method selection and discusses the improvements that are required in existing models to make them more directly useful in decision support. A summary from case study visits to utilities in terms of how cities actually make these decisions is also provided. Proposed improvements for the next steps needed to improve current method selection support software are also discussed.