Cross Bore Safety

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Some Paths Should Never Cross…

A cross bore is the intersection of an existing underground utility by a second utility, which results in direct contact between the utilities.

Cross Bore Illustration

That contact compromises the integrity of either utility and can create a hazardous condition. Be alert when unblocking an underground sewer line. A cross bore could exist and cause a natural gas emergency. In areas where trenchless technology has been used to install underground utility lines, there is a possibility that our gas pipeline may cross through a sewer pipe, resulting in a cross bore.

Not all sewer lines have been mapped or installed with tracing technology, and cannot be located on private property before drilling. If a clog in the sewer line occurs, plumbers and homeowners often use a rotating cutter that can be inserted to clear the line. While good for clearing out objects such as tree roots, these devices can also cut through plastic natural gas distribution lines, communication lines, water lines and electric lines that were unintentionally installed through sewer lines. If it is a gas line, natural gas could enter the sewer system and create a hazardous situation, including explosion, complete destruction of the structure, and injury or death of occupants.


  • Call or ask your sewer clearing professional to contact Intermountain Gas at 800-548-3679 prior to clearing your sewer line. We will promptly arrive to locate and mark our natural gas pipelines, free of charge.

  • Never use a sewer clearing machine to clear a line until the obstruction has been identified.

  • Take action if you notice bubbles rising through standing water or in the toilet bowl or a strong odor of natural gas. If these signs are present, immediately stop what you are doing and evacuate the premises (leaving the exit door open). From a safe distance, call 911 and Intermountain Gas at 800-548-3679.

Additional Cross Bore Information

Visit the Cross Bore Safety Association website:

or the Call Before You Clear website:

photo example of a cross bore

photo example of a cross bore

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