A contractor is removing old natural gas distribution pipe(8" steel) from a roadway. Is this pipe considered hazardous waste and need to be sent to the landfill or is it good to go to metal recycling yard? The pipe still smells like natural gas.
What you are probably smelling is methyl mercaptan or ethyl mercaptan, added in tiny quantities to the distribution system to make gas leaks easily detectable.
From bioreference.net:
It can react with or be adsorbed metallic pipe materials, particularly when corroded, and will bind to soil particles. Explosions have occurred where underground gas leaks went unnoticed because the mercaptan was filtered out by the soil.