Gas Pipeline Ruptures and Neighborhood Evacuations¶

Natural gas pipeline ruptures and high-pressure transmission line leaks pose extreme fire, explosion, and asphyxiation hazards. Underground distribution mains damaged by excavation or ground movement can fill nearby structures and soil with volatile gas.

Recognizing Gas Leaks and Ruptures¶

• Smell: A strong sulfur or rotten egg odor added to natural gas (mercaptan) signals escaping gas.
• Sound: Hissing, whistling, or loud roaring sounds near gas lines, meters, or excavation zones.
• Sight: Dirt blowing into the air, persistent bubbling in puddles or standing water, dead or dead-looking vegetation in an otherwise green area, or dry spots in moist soil.

Immediate Safety Actions¶

1. Evacuate Immediately On Foot: Leave the building or area on foot right away. Walk crosswind away from the leak site.
2. Do Not Create Any Sparks or Flames:
3. Do not flip electrical light switches or unplug appliances.
4. Do not use telephones, cell phones, flashlights, or electronic devices within or near the odor zone.
5. Do not start motor vehicles, turn on engines, or operate power tools nearby.
6. Do not strike matches, use lighters, or smoke.
7. Leave Doors and Gates Open: Leave doors open as you exit to help prevent gas concentration indoors, provided doing so does not delay your safety.
8. Call Emergency Services From a Safe Distance: Once you are at least 100 m (330 ft) away and upwind from the suspected leak area, call 911 or your local emergency number and your local gas utility.

Evacuation Perimeters and Neighborhood Safety¶

• Maintain an initial perimeter of at least 100 m (330 ft) for residential low-pressure line leaks and at least 800 m (0.5 mi) for high-pressure transmission pipeline ruptures.
• Do not attempt to turn off utility shut-off valves on high-pressure pipelines or street mains. Leave pipeline operations to qualified utility personnel and firefighters.
• Wait for official clearance from emergency responders before returning to your home or business.