Response tactics for outdoor leaks differ from those for indoor leaks, as gas leaks from outdoor sources may involve higher-pressure pipelines.

In addition to the distinctive, sulfur-like odor of mercaptan, look and listen for any of the following:

• Dirt being blown into the air
• Dead vegetation in an otherwise green area
• A dry spot in an otherwise moist area
• Fire coming from the ground or appearing to burn above the ground
• Water bubbling or being blown into the air
• Roaring, blowing or hissing sounds
• A damaged connection to a gas appliance
• An exposed pipeline after an earthquake, fire, flood or other disaster
• A fire or explosion nearby