Tips of the Trade Brought to you by Duke Energy
Be Alert for Cross Bores

Duke Energy Emergencies
Carolinas: 800-769-3766
Florida: 800-228-8485
Indiana: 800-343-3525
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Know what's below. Call 811 before you dig.

Call Before You Clear a Sewer Clog or Blockage
Some sewer laterals may have natural gas pipelines intersecting them. So before clearing any clogged sewer or drain lines, it’s critical that you contact Duke Energy to ensure you can proceed without the risk of puncturing a natural gas line. Please call our dedicated 24-hour emergency/dispatch number at 800-634-4300.

How Natural Gas Lines Intersect Sewer Lines
Duke Energy uses horizontal directional digging to install natural gas lines underground beneath streets, driveways and mature trees. This approach is common in the utility industry because it causes less environmental disruption than open digging. Duke currently uses techniques to detect sewer lines during directional digging. However, because many older sewer lines are not easily identifiable, in the past we may have unintentionally bored our gas lines directly through sewer lines in what are known as “cross bores.”

Know the Dangers
A cross bore in a sewer lateral will impede flow and lead to eventual blockage. A worker who attempts to remove the blockage can accidentally cut the gas line and cause a dangerous release of natural gas. The resulting loss of gas service may not be immediately apparent. Gas can migrate undetected through the lateral and concentrate in sewer lines and nearby structures, causing a potential hazard.

Take these Steps to Work Safely:

  • Before clearing. Always call Duke Energy at 800-634-4300 before you clear sewer lines. We will determine if any conflicts exist between our natural gas lines and the blocked sewer line. If we detect a conflict, we will notify the customer and repair/reroute the gas line.
  • During clearing. Play it safe and always proceed as if a cross bore might be present. As you go, feel for resistance that does not resemble a tree root or other common obstruction. Natural gas utility lines are typically plastic. If you must use a cutting tool, look for yellow or orange plastic on the blades when you withdraw it. Watch for bubbles escaping from the entry point of the cutting equipment or toilet and/or use a combustible gas indicator (CGI) or other gas detection equipment, if available.
  • If you suspect a gas leak. Immediately warn all inhabitants and evacuate the area. Do not use a flame or anything electrical, as a spark could ignite the gas. From a safe location call 911 and Duke Energy at 800-634-4300 immediately.

Would You Like to Know More?
Additional digging and overhead guidelines, case studies, instructional videos and training tools can all be found, at no charge to you, on Duke Energy’s e-SMARTworkers website.

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