What is a cross bore?
A cross bore is an unintended intersection of an existing underground utility such as a sewer or septic line by a natural gas line. This happens when utilities are installed using trenchless installation techniques such as directional drilling or boring.
Because the drilling operator can’t see the head of the equipment or other buried utilities during installation, they rely on accurate “locates” to show them the location of other existing underground utilities. Unlike other types of underground utilities, sewers are traditionally difficult to locate. They are made of non-metallic materials and are installed without any type of aid to allow them to be located from above ground.
Since the identification of the cross bore risk, utilities have implemented practices to eliminate the potential risk of creating new cross bores.
Does this affect me?
Instances of natural gas lines intersecting sewer lines are rare but they have been found across Ontario. Cross bores may be present for years with no indication or immediate hazard prior to a sewer blockage. However, once clearing equipment is used outside the walls of a building, there is potential for this equipment to damage a gas line. If the gas line is damaged through sewer cleaning activity, natural gas may enter the sewer line and pose an immediate safety risk. A cross bore has the potential to exist even if there is no gas service to a property.
When should I call?
The most important thing you can do is have yourself or your plumber call Ontario One Call at 1-800-400-2255 and request a FREE sewer safety inspection before using mechanical clearing/cutting or high-pressure water jetting equipment to try to clear a blockage outside the walls of the building. A blocked sewer can be a stressful situation and you’ll want it resolved fast. That’s why these inspections are available 24/7 and treated as emergency calls with a goal of resolving the issue as quickly as possible.
What happens once I call?
Once the call is placed, Ontario One Call will notify the service provider in your area who will attend and to verify if you do or do not have a cross bore on your property. If there is no potential of a cross bore, clearing activities will proceed. If there is a potential cross bore the call will be escalated to the appropriate utility.
Is there any cost to me?
No, the inspections performed are FREE.