Rehabilitation of an Industrial Water Main Using Multicriteria Decision Analysis

This paper demonstrates the application of multicriteria decision analysis (MCDA) methodology in a real case study aiming to choose the best rehabilitation intervention of an industrial water main. This methodology is composed of three main stages: problem identification, structuring, and evaluation. Problem structuring, a crucial stage for the outcomes, includes identifying objectives, selecting scenarios within the analysis period, defining problem alternatives, and defining the problematic type. Problem evaluation includes the selection of assessment metrics, selection of the aggregation method, application of the method, and a sensitivity and robustness analysis. Two scenarios, nine assessment metrics, and seven alternatives are established, and two ranking methods (the additive model and ELECTRE III method) are used to compare the alternatives. The results show that the best solution corresponds to building a new pipe and deactivating the existing one, as it significantly reduces the pipe failure risk and O&M costs, whereas the worst solution is always the status quo case, since it is the only alternative that does not improve the system performance, independently of the ranking method and the analyzed scenario.

A review of water quality factors in water main failure prediction models

Water main failure can result from structural failure of the pipes, changes in water quality, or a combination. This paper is a review of articles evaluating water quality factors and subfactors in the development of water main failure prediction models since 2000. A systematic process was implemented to capture the most relevant current published papers. Of 4598 published papers, 304 were screened for water main failure prediction models. The resulting set was further screened for water quality factors and subfactors (e.g., pH, temperature, etc.). This led to the identification of 18 relevant research papers, and each of these was reviewed comprehensively. The water quality-related findings, as well as combinations with other information – such as type of prediction model and type of prediction – are summarized and discussed.

Current water main rehabilitation practice using trenchless technology

The market for water infrastructure rehabilitation is growing rapidly due to the increasing age of underground utilities. Currently, two common water main rehabilitation methods exist: cured-in-place pipe (CIPP) and polymer spray-on coatings. CIPP can provide structural support for both internal and external loads, while spray-on techniques provide chemical resistance as well as adding minor strength to the existing pipe. This paper summarizes water main rehabilitation practice using CIPP and spray-on methods. The history of trenchless rehabilitation technology is discussed, as well as current methodologies and products for water mains. The design, installation, and monitoring of water main rehabilitation products are also summarized, along with the associated risks. Quality assurance and control (QA/QC) methods are included for evaluating existing products and procedures.