You are here:
Demonstration and Evaluation of State-of-the-Art Wastewater Collection Systems Condition Assessment Technologies
Citation:
Selvakumar, A., M. Tuccillo, K. Martel, J. Matthews, AND C. Feeney. Demonstration and Evaluation of State-of-the-Art Wastewater Collection Systems Condition Assessment Technologies. Journal of Pipeline Systems Engineering and Practice. American Society of Civil Engineers (ASCE), Reston, VA, 5(2):04013018, (2014).
Impact/Purpose:
Our nation’s infrastructure is generally in poor condition (given a GPA of D+ in 2013 ASCE Report Card), and wastewater collection systems are no exception. In the U.S., there are approximately 16,000 sewer systems serving 190 million people and incorporating approximately 740,000 miles (1,190,660 km) of public sewers, plus 500,000 miles (804,500 km) of private lateral sewers (USEPA 2010a). Some components of the U.S. wastewater infrastructure are well over 100 years old. The combination of age, neglect, and mishaps give rise to 23,000 to 75,000 sanitary sewer overflows (SSOs) per year, along with the resulting illnesses and environmental degradation (USEPA 2011). The latest 2013 infrastructure report card issued by the American Society of Civil Engineers (ASCE) provides a “D” grade for wastewater infrastructure (ASCE 2013). ASCE (2013) indicated that as much as 900 billion gallons of raw sewage are released yearly because of the state of wastewater infrastructure. It should be noted that the grade has worsened between 1988 and 2013 from C to D.
Description:
Reliable information on pipe condition is needed to accurately estimate the remaining service life of wastewater collection system assets. 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, electro-scanning, 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, MO 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, CCTV) and laser scanning provided pipe condition above the water line, whereas sonar assessed conditions below the water line. Electro-scanning 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 multi-sensor inspection were $4.48 per ft of pipeline inspected as compared to $3.14 per ft for electro-scanning, $1.05 per ft for zoom camera, and $2.98 to $3.19 per ft for CCTV.
