USEPA Sewer Electro Scan Field Demonstration Revisited

摘要

Potential Rain Dependent Infiltration (RDI) flows are a critical parameter for the design andrnprioritization of sewer collection system infiltration mitigation projects. An estimate of RDIrnflows may be obtained from the defect current measured by an electro scan of a pipe. RDI flowrnhas been calculated for the pipes electro scanned during the USEPA sponsored fieldrndemonstration. The field demonstration included CCTV inspection of the pipes. For pipe defectsrnthat are potential sources of RDI, the comparison with CCTV showed that electro scan is highlyrnreliable, identified 2.1 times more defects and that many of the defects missed by CCTV werernpotentially the largest sources of infiltration. The distribution of the electro scan estimated RDIrnflow was significantly more variable than that shown by CCTV. This reveals the potential use ofrnelectro scan to target and design rehabilitation projects that will significantly reduce RDI atrnconsiderably lower cost.