A natural gas leak is typically recognized by its odor. Pure natural gas is colorless and odorless but before it is delivered to your home, an odorant called mercaptan is added to give gas its distinctive odor so you can smell a leak immediately. Mercaptan makes gas smell like sulfur or "rotten eggs".
Although natural gas is colorless, there are still visual and audible signs that may indicate a natural gas leak. Blowing dirt, dead vegetation in an otherwise green area and bubbling water are all indications that a natural gas leak may have occured. Also, if you hear a hissing or whistling sound, it could be a natural gas leak.
If you ever suspect a natural gas leak, contact your LOCAL NATURAL GAS OPERATOR immediately.