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Low dig technology

The "low dig" technology used to rehabilitate the water mains does not require the entire length of the water main to be excavated in order to perform the structural lining.  The added benefits of this process are:

  • less need for trench work
  • fewer traffic disruptions
  • utilization of existing water mains
  • shorter duration of work, lower cost compared to complete replacement
  • minimized disruption to neighbourhood.

The structural lining process generally consist of the following:

  1. A temporary water main (blue or yellow PVC pipe) is installed above ground as well as a temporary water service (blue rubber hose) to each building normally connected to the water main.  This temporary water service is connected to the outside tap for residential application.  A wye connection is installed on the outside tap so a garden hose can be connected to the one side, while receiving water on the other side.
  2. Excavation pits are placed at approximately 300 foot intervals along the water main.
  3. The existing water main is cleaned by dragging metal scrapers or spraying high pressure water through the pipe several times to remove the iron build up.
  4. The main is structurally lined using the cured in place pipe liner.
  5. The newly lined water main is disinfected and bacteriologically tested and returned to service.
  6. Restoration of affected curbs, street, sidewalk and driveways is completed.