For more information, download a copy of the EPA Benchmark report by clicking on the following link U.S. EPA Benchmark Study.
*The U.S. Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, Water Supply.
For large pipes the existing flow level can be used as long as it is realized that only that part of pipe submerged is Electro-scanned.
For sewer laterals, it is best to submerge the entire segment of the pipe, from the sewer clean-out to close to the mainline sewer connection.
In the case of pipe relining projects, the most difficult task is re-connecting service laterals while maintaining the water tightness of the liner. CCTV cannot effectively examine the water tightness of this connection. Electro Scan readily detects the potential of water flowing through the lateral connection and the connection of the liner to the manhole.
The same is true for post-grouting projects. According to ASTM 2304-03, Standard Practice for the Rehabilitation of Sewers Using Chemical Grouting, and ASTM 2454-05, Standard Practice for Sealing Lateral Connections and Lines from the Mainline Packer Method, Using Chemical Grouting, a seal is not achieved by simply placing an internal grout ring. Grout must be placed outside the joint. This is not able to be verified by a CCTV camera. Again Electro Scan is able to determine water tightness of a grouted joint.