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Natural gas lines can sometimes intersect with sewer lines. When this happens it is known as a sewer cross bore.

When left undisturbed, sewer cross bores do not present a safety risk.

What you need to know about sewer cross bores

Utility companies across North America began using no-dig or trenchless tunneling technology back in the 1980s as a way to install underground utilities. The method results in less damage to property, roadways, and tree roots. It also saves both time and money.

On rare occasions, natural gas pipelines installed with trenchless tunneling methods may inadvertently intersect sewer service lines. (Remember, left undisturbed, these intersections – cross bores – do not pose a safety risk.) When new gas services are installed today, contractors use techniques that ensure new sewer cross bores are not created.

In the interest of public safety and in accordance with requirements of the Technical Standards and Safety Authority (TSSA), gas companies have implemented communications programs to inform customers and plumbers of this risk. All gas companies in Ontario will provide a free sewer safety inspection for customers to ensure that there is no cross bore. 

This video provides a brief overview so that you know what to do if your sewer line gets blocked beyond your foundation walls.

If you have a blocked sewer line beyond the outside wall of your building, your attempt to clear it could damage the gas line, causing natural gas to leak into your home or building.

Before you call a plumber, or rent motorized or water jetting equipment (also known as an electric sewer snake or auger) to clear a sewer blockage, phone Ontario One Call at 1-800-400-2255 to arrange a free Sewer Safety Inspection. Your gas utility will respond within two hours.

Before you clear an outside sewer blockage, always confirm that you are not at risk of damaging a gas line!

Ontario 1 Call 1-800-400-2255

For emergencies, call us 24/7 at 613-546-1181. If you have any questions about sewer cross bores, call Utilities Kingston at 613-546-1181.