Cross Boring

Cross Boring

Blocked Sewer or Septic?
Call MNG Before You Clear It!

Before renting equipment or hiring a contractor to clear a blocked or backed-up sewer or septic pipe, there’s an important call you need to make.

Call Maine Natural Gas at 877.532.5636. Our professionals will promptly meet you or your contractor on-site to mark out buried natural gas pipelines and confirm there is no concern about cross-boring.

Cross-boring is a rare situation where a natural gas line has been inadvertently installed through a sewer or septic pipe. If the pipe becomes clogged, your efforts to clear it can damage the intersecting gas line and allow natural gas to escape.

There is no cost for the site visit and inspection by MNG professionals. If cross-boring is discovered, MNG will repair both the sewer and gas line at no cost to you.


  • If you have a blocked or backed-up sewer or septic pipe, call MNG at 877.532.5636 before clearing it. If you have hired a contractor, insist they make the call before starting work.
  • At least 2 full business days before any job requiring excavation, contact DigSafe to have natural gas lines and other utilities marked out. Dial 811 or visit
  • If you smell natural gas or suspect a leak, leave the building or area immediately and call MNG from a safe place at 877.532.5636, or dial 911 if there’s an imminent threat to life or safety.


MNG has an ongoing program to prevent cross-boring and mitigate risks. We partner with local contractors and local municipalities to conduct inspections on a timely basis and take any necessary actions.


Your plumber or drain-cleaning professional may recommend inserting a camera in your sewer to look for gas pipelines. This is a good practice, and if a gas pipeline is found, you’ll be reimbursed for the camera inspection. However, you should still call MNG to locate the gas pipeline, as it may be concealed behind other obstructions.


  • Stop all work
  • Contact MNG
  • If you suspect a natural gas leak by smelling, seeing or hearing gas escaping:
    • Leave and instruct others to leave the area
    • Call 911
    • Contact the gas company for the area
    • Do not operate any equipment
    • Eliminate any source of ignition
    • Do not operate any pipeline equipment or facility
    • Proceed with your work when the area is safe


Here is some additional information about cross-boring from the Gas Technology Institute:

For Plumbers and Contractors:

For Homeowners:

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