TRIC Trenchless Pipe Bursting An entrance and exit hole needs to be made from where the new pipe, which is called H.D.P.E. -- High Density Polyethylene -- can be pulled through the old line with a pulling cable. After pulling the new line, the ends of the H.D.P.E. pipe need to be connected to the existing pipe and the holes filled in. This process usually requires at least one excavation hole outside the structure and another access through the basement floor. For a more detailed explanation of the process with pictures vist: http://www.trictrenchless.com