Condition Assessment of Water Distribution Pipes

Abstract

With average pipe replacement rates in the United States at about once in 200years, effective assessment of pipe condition is required to plan renewal programs for distribution systems. The paper is based on a project for the American Water Works Association Research Foundation and presents findings and a management framework about utility practices in condition assessment and it validates the framework through comparisons with practices in leading utilities. The project findings indicated that utilities can utilize available information much better than they do. However, they are impeded by lack of a standard procedure for recording data on leaks, breaks, and condition indicators. Ideally, the large amount of information involved would be consolidated into a composite condition index, but this is not feasible. Advanced applications are required for the future. These might include real-time assessment, smart pigs to collect data, small chip sets, and automated pipe data registration. Research needs are indicated in nondestructive testing, leak detection and loss measurement, causes for pipe, joint, lining, and coating deterioration, and in situ methods to test condition. While condition assessment is a promising concept, it is not applied consistently. In the past, condition information was used by operations and engineering departments. The same decisions still require condition information, but organizations are more integrated, have newer methods available, and face higher standards and expectations than in the past. When utilities manage their distribution capital programs better, it can lead to organizational improvement across the board because different departments can work together to improve the entire system. By use of the proposed framework, combined with effective information systems, operations improvements, and capital improvement programs, utilities can optimize returns on their investments in distribution systems. Utilities will continue to face obstacles such as lack of records, inability to inspect pipes while in service, and not being supported for funding by boards or councils. In the end, the solutions may already be within the grasp of utilities, through better management of existing information.