INFRA 2015
Résumé de la conférence
Reducing Infiltration and Inflow (I&I) is an increasing priority for government and private entities with a stake in sewage treatment. Given the increasing costs for power and the emphasis on conservation, I&I reduction is more and more becoming the prime driver for repairing sewer systems. Achieving significant I&I reduction is easy with unlimited funds – the problem lies in optimizing its reduction for any given budget available. This inevitably means identifying and then prioritizing sources and then selecting repair methods to get the maximum reduction for a minimum investment. While advances in software and intelligent asset management systems using PACP codes have assisted in prioritizing sewer rehabilitation for NON I&I related works, these systems are challenged when it comes to I&I reduction. The difficulty is the inability to directly measure and quantify individual I/I sources.
A new approach using a low voltage electric current is being used by municipalities to provide another layer of information. The electric current data can identify and quantify I&I in sewers that is undetectable even to an expert eye looking at sewer CCTV recordings. The electric current variation method measures electric current leakage from non-metallic sewer pipes - through special algorithms this scanning technology can simultaneously identify and quantify potential water infiltration for each meter of sewer scanned.
This paper will show the results of this new technology in several municipalities in Ontario with an emphasis on ground truthing and directly comparing the electric current data to CCTV PACP data, expert visual analysis and with other nondestructive pipe testing methods. The results to date indicate that electric current surveying is an excellent tool that provides unbiased, quantifiable and reliable data that excels in the prioritization of rehab work, specifically as it relates to I&I reduction. This will be updated with additional findings and study being performed.