How to Recognize a Natural Gas Leak

Natural gas leaks are rare but can occur in a variety of places, so it is important to be aware of the signs.

Because natural gas is colorless and odorless, Unitil adds a harmless, non-toxic chemical that makes it easier to detect a gas leak before it can create a hazardous situation. The chemical additive is called Mercaptan, and it gives the rotten eggs smell to natural gas. Natural gas is also lighter than air, so if it escapes, it rises into the air and dissipates quickly.

Signs of a Leak

A gas leak is often recognized by sight, sound or smell.

Dirt being blown or appearing to be thrown in the air
Water bubbling or being blown into the air at a pond, creek, river or other wet area
Fire coming from the ground or appearing to burn above the ground
Dead or dying vegetation on or near a pipeline right of way in an otherwise green area

What to do if you suspect a leak →

Residential Methane Detectors

An additional layer of detection

A residential methane detector alerts residents of natural gas leak inside a building. The detector works like a smoke detector, using an internal sensor that measures and monitors the concentration of methane in the air. (Natural gas consists primarily of methane.) The detector will activate an alarm when safe levels of methane are exceeded.

There are a range of detectors available on the market. Unitil recommends that whatever you purchase is UL rated (UL 1484).