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Field Demonstration of Electro-Scan Defect Location Technology for Condition Assessment of Wastewater Collection Systems
Citation:
Feeney, C., C. Wilmut, K. Martel, F. LAI, AND A. SELVAKUMAR. Field Demonstration of Electro-Scan Defect Location Technology for Condition Assessment of Wastewater Collection Systems. 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, electro-scan (FELL-41), 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 drinking water and wastewater treatment and conveyance systems. This paper will highlight field demonstration results for the electro-scan (FELL-41) technology. Electro-scan (FELL-41) uses the variation of current flow through the pipe wall to identify pipe defects that are potential leaks; standard practice is outlined in the ASTM standard F2550-06. It can be used in non-conductive (i.e. non-ferrous) sanitary sewer mains, gravity lines, and service laterals. The field demonstration will be performed in an area with small diameter (8-in. and 12-in.) vitrified clay pipe and limited sections of PVC pipe. This technology requires the pipe in the region of the probe to be fully surcharged to test its full circumference (360°). For 8-in. to 12-in. lines, the most efficient approach is to use a sliding pipe plug in conjunction with a jet truck. Technology performance will be measured in terms of versatility, accuracy, repeatability, and inspection time/production rate. The evaluation of the total cost 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. Existing flow conditions are often an important and challenging aspect of the inspection process. High flow conditions and high water velocity present difficult operating conditions. Low flow conditions require supplemental flow from fire hydrants or other sources. Benefits of Project: Findings from the field demonstration will be used as a basis for developing practical guidance to help utilities develop and implement condition assessment programs. Electro-scan (FELL-41) technology can be used to estimate the magnitude and location of potential leaks along a pipeline, helping utilities better understand and control sources of infiltration. Pipe defects are coded automatically by the accompanying software. Electro-scan (FELL-41) technology directly measures leak potential, independent of external conditions that are temporal in nature (e.g., seasonal, wet weather). Its use of direct measurements provides a quantitative analysis of leak potential without relying on visual observation. 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.