Recognizing and Responding to a Leak

Pipelines are, statistically, the safest way to transport energy products like natural gas. However, as with any method of transportation, accidents can happen. In the event of a pipeline emergency, it’s important you know the warning signs and protect yourself.​

When natural gas is transported through a transmission pipeline like Alliance, it is odorless. An odor similar to rotten eggs is added when the gas enters a distribution pipeline system to your home, allowing you to detect a leak. Signs of a natural gas leak include:​

  • An odor similar to rotten eggs, diesel, oil or propane
  • A loud whistling or roaring sound
  • A steam-like cloud
  • Unexpected frost on the ground
  • Bubbling in wet areas
  • Dying vegetation along the right-of-way

​Actions to Take in the Event of a Pipeline Leak​


  • Operate phones or electrical devices
  • Start vehicles or machinery​ in the area
  • Come into contact with leaking substances


  • Extinguish/eliminate ignition sources, like cigarettes or machinery
  • Alert others in the vicinity
  • Leave the area immediately on foot, in an upwind direction​

Remember: if it’s too hot or too loud, you’re too close.​ If you suspect a leak, immediately leave the area on foot. Call 911 and follow their instructions.​​


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Unusual hissing, whistling or roaring

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Unlike the natural gas delivered to your home, odorant is not added to gas on the Alliance system. However, a leak on the Alliance system may have a natural petroleum smell.

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Steam-like cloud, frost on the ground, dirt blowing from the ground

Bubbling in wet areas

Dead or discolored vegetation​​​​​​​​​