Throughout Alberta, there have been a few discoveries of the existence of cross bores – this when one underground utility inadvertently crosses through another during installation.
Cross bores can go unnoticed for years or decades. While there is no immediate danger, there could be serious consequences if rotating equipment is used clear a blocked sewer. This can damage the gas line to the point of gas leaking into the sanitary or storm systems and then into buildings. Municipalities completing routine sanitary and storm mains maintenance can also damage the gas line.
While it’s unlikely to occur, here’s what you need to know about cross bores:
- When clearing a blocked sewer, be aware natural gas lines could have inadvertently penetrated sewer service lines during installation.
- Unless the natural gas line is damaged or there is interference, it does not pose an immediate safety risk; however, clearing a sewer service line that’s intersected with a natural gas line could pose danger.
- When planning to clear a sewer line, video inspect before the use of rotating equipment (e.g. motorized auger, power-snake or other root-cutting equipment) to clear a sewer service line. This is necessary if the blockage is beyond the outside wall of a building.
Should you suspect the presence of a cross bore, please contact ATCO to investigate, verify, and repair if necessary. The ATCO Call Centre number is 310-5678. If you have an emergency, please call 1-800-511-3447 or 911.