Horizontal Drilling/ Microtunneling - This method is used for installing a new trenchless sewer line in new ground. Like the name suggests, microtunneling involves digging an access point and using a microtunnel boring machine (MTMB) to carve out a small horizontal tunnel where the piping will lay, and then inserting the piping through said tunnel.
Pipe Ramming - Same as microtunneling, pipe ramming is used for trenchless installation of a new line. And same as microtunneling, pipe ramming carves out a pipe-shaped tunnel with minimal surface disruption. This method uses pneumatic percussive blows to drive a pipe through the soil and filter the soil in through the pipe-ramming device, instead of compacting it outside the pipe which could make cave-ins more likely.
Sliplining - Sliplining is used for repairing pipes with leaks or structural integrity issues. One of the oldest methods of trenchless tech, this technique involves uncovering a small section of the line and inserting a small “carrier pipe” inside, and then sealing any cracks by filling the space between the two pipes with grout.
Shotcrete/Gunite - This is another method used to repair underground lines that have been corroded or damaged. Shotcrete is the process of spraying a solution of cement and sand over an area using a pressurised hose. For sewer line repair, after accessing the line, shotcrete can be sprayed on the damaged section, filling up cracks in the interior and protecting against further corrosion after it sets.
Pipe Bursting - This method is useful for replacing a defunct or beyond-repair underground pipe. Pipe bursting involves digging two access points to the old line, and running a cable through the line with a “bursting head” attached on the front and the new pipe on the back. A powered winch pulls the cable through and the bursting head destroys the old pipe, pushing it out of the way while laying the new pipe behind it.