Outdoor gas leaks: Warning signs

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, rotten-egg or sulfur-like odor of mercaptan, look and listen for any of the following:

• A hissing, whistling or roaring sound
• Dirt being blown into the air from a hole in the ground
• Continuous bubbling in water
• Dead or dying vegetation in an otherwise moist area over or near a gas pipeline
• Frozen ground in warm weather