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Field Demonstration of Multi-Sensor Technology for Condition Assessment of Wastewater Collection Systems (Abstract)
Citation:
Tuccillo, M. E., J. Graham, C. Feeney, F. LAI, AND A. SELVAKUMAR. Field Demonstration of Multi-Sensor Technology for Condition Assessment of Wastewater Collection Systems (Abstract). Presented at WEF Collection System Specialty Conference, Raleigh, NC, June 12 - 15, 2011.
Impact/Purpose:
To inform the public.
Description:
The purpose of the field demonstration program is to gather technically reliable cost and performance information on selected condition assessment technologies under defined field conditions. The selected technologies include zoom camera, focused electrode leak location (FELL), and a multi-sensor platform that includes laser, sonar and digital scanning. The field demonstration will be conducted in Kansas City, MO, in areas of the collection system with known operational issues due to root intrusion and inflow/infiltration (I/I). The project is part of a USEPA research program “Innovation and Research for Water Infrastructure for the 21st Century.” The program is being implemented by the USEPA Office of Research and Development to generate science and engineering knowledge to help utilities reduce the cost and improve the effectiveness of operation, maintenance, and replacement of aging and failing drinking water and wastewater treatment and conveyance systems. This paper will highlight field demonstration results for the multi-sensor unit that includes laser, sonar and digital scanning. The field demonstration will involve inspection of a 20-ft deep of 54-in. to 72-in. interceptor constructed in the 1960’s. The performance of each technology will be measured in terms of versatility, accuracy, repeatability, inspection time/production rate, and miscellaneous technology-specific metrics. The evaluation of the total cost of each condition assessment technology includes factors such as traffic control, cleaning requirements, labor, equipment, and disruption of service. Results will be compared to a baseline condition assessment completed using traditional in-line CCTV inspection. Benefits of Project: Findings from the field demonstration study will be used as a basis for developing practical guidance to help utilities develop and implement condition assessment programs. The multi-sensor technology using laser, sonar and digital scanning allows inspection of the full circumference of the pipe. Dewatering is not required prior to inspection and the inspections can be conducted under any flow conditions. Laser scanning generates a cross-sectional profile of a pipe’s interior wall by highlighting the shape of the sewer. The technology detects changes in the pipe’s shape which may be caused by deformation, corrosion or siltation. Laser scanning equipment measures pipe geometry and surface condition with great precision above the water line. This technology is generally used in conjunction with standard in-line CCTV inspection to provide additional information on pipe condition. It can be used to assess the condition of any pipe material. Internal diameter and deflection graphs are used to quantify internal pipe wall material loss/gain or deformation at a given payout location. The laser scanning system records all measurements for post-inspection reporting. Sonar is used to inspect pipe surfaces below the water line. As the sonar head passes through the pipe, it sends and receives high frequency ultrasonic signals, which are reflected by the pipe walls. The signals change when there is a change in the material it is being reflected by, allowing for the detection of defects. The time between signal transmission and receipt can be used to determine the distance between the sonar head and the pipe wall and to estimate sediment level accumulating in the pipe. Digital scanning employs one or two high resolution cameras equipped with wide angle lenses that provide a 180-degree field of view of the pipe interior above the water line. The technology provides two types of images: an unfolded view of the sides of the pipe and a circular view down the length of the pipe. The unfolded view enhances the computer aided measurement of defects and objects. The digital scan can be reviewed and coded at any time subsequent to the inspection. The image can be analyzed in the post-inspection process to determine precise measurements of identified defects. Status of Completion: The field demonstration is expected to be done by August 2010. Data analysis and the final report will be completed by the end of the year. Conclusion: The conclusions of the paper will be developed following the field demonstration program.