Demonstration and Evaluation of State-of-the-Art Wastewater Collection Systems Condition Assessment Technologies

Abstract

Condition assessment of wastewater collection systems is a vital part of a utility’s asset management program. Reliable information on pipe condition is needed to prioritize rehabilitation and replacement projects, given the current state of our nation’s infrastructure. Although inspections with conventional closed-circuit television (CCTV) have been the mainstay of pipeline condition assessment for decades, other technologies are now commercially available. Five of these innovative technologies were selected for field trials under the U.S. Environmental Protection Agency (USEPA) demonstration program: zoom camera, electroscanning, digital scanning, laser profiling, and sonar. The goal of the field demonstration was to evaluate the technical performance and cost of these technologies. The field demonstration was conducted in August 2010 and was hosted by the Kansas City, Missouri Water Services Department. The innovative technologies were compared to CCTV inspection. Each technology identified maintenance and structural defects by collecting data or images of the pipe condition. The camera technologies (i.e., digital scanning, zoom camera, and CCTV) and laser scanning provided pipe condition above the water line, whereas sonar assessed conditions below the water line. Electroscanning detected leakage-related defects anywhere along the pipe circumference. Costs were compared for different inspection technologies based on actual costs for planning, field work, data analysis, and reporting. Total costs for the multisensor (digital, laser, and sonar scanning) inspection were $14.71 per m of pipeline inspected as compared to $10.31 per m for electroscanning, $3.46 per m for zoom camera, and $9.78 to $10.48 per m for CCTV.