ADVERTISEMENT
See Inside May 2011

All's Well That Ends Smells

Some smells always belong, but do not always remain, outside



Illustration by Matt Collins

Editor's note: This article was printed with the title, "O Mercaptan, My Mercaptan" in the May issue.

Friday, February 25, 2011: A date which will live in odiferous infamy. At least at my house.

All seemed well that morning when the rains came. I was warm and dry and didn’t need to leave the comfort of home. But that comfort swiftly departed. First, I heard the glug glug glug. Then I picked up a whiff both faint and foul. Something was entering the bathroom that should only exit the bathroom—raw sewage was reversing its natural course and fighting its way back into my house.

The whiffs got stronger. Human waste includes some fascinating and fragrant organic compounds. Take skatole. (Please.)

Skatole bears a heavy responsibility for making poo smell phooey. But remember the axiom: it’s the dose that makes the poison. Because in low concentrations, according to Wikipedia, skatole “has a flowery smell and is found in several flowers and essential oils,” such as orange blossoms and jasmine. It is even used—again, in very small amounts—in perfumes. Think about that when dabbing behind the ears. And Wikipedia notes that cigarette manufacturers add skatole as (drum roll) a flavoring ingredient. Just another reason to stop smoking. In addition, waste contains various stinky sulfur compounds, collectively called thiols or mercaptans. They are not your friends.

When sewage is backing up into one’s home, the to-do list instantly becomes an un-doo list with only one item: get the plumbers to come immediately. Upon their swift arrival, they unsealed the trap to gain access to the line, which also sent the incoming waste fluid into the subbasement—still bad, but a big improvement. They then sent a camera down the line to examine the problem, performing their version of the closely related diagnostic technique of colonoscopy.

Thus, they found that the clay pipe leading from my house to the city sewer line had been severed. Instead of running slightly downhill, the pipe now pitched slightly skyward. (Technical plumbing lingo: there was a sag in the line.) In the former case, gravity was my friend, gently pulling waste away. But in this new configuration, gravity was a relentless enemy, allowing all things flushed to drift back toward the house. Add the heavy rain, and glug glug glug.

By late afternoon I had hired a contractor to tear up the street and replace the busted clay pipe with a cast-iron version this time. I hope to finish paying for this rather costly work before half of the cast iron’s alloyed carbon 14 decays. (That’s about 5,730 years for those keeping score at home.)

With all this hitting the fan, I was alarmed when my next-door neighbor called to ask me about all the black stuff in front of his house. I told him I’d meet him on our adjoining porches. To my relief, his porch was merely speckled with soot. I looked up the wall and saw that the soot was clearly emerging from the chimney that our furnace exhausts share. “What will we do?” he asked. I explained that we would do nothing because my gas fuel (naturally odorless but laced with mercaptans to make any gas leaks instantly obvious) was unlikely to be producing particulates. He, on the other hand, would have to have his oil-heat system examined for incomplete burning.

With that crisis averted, I turned my attention to tracking the location of the mouse that my cat had caught and was playing Ping-Pong with in the living room. (The mouse being the ball in this metaphor, not the opponent.) The frightened mouse contributed his own tiny measure of mercaptans to the mix.

In the evening, with all situations under semicontrol, I headed out to a local restaurant. As I drove on an unlit, woodsy road, a fluffy, whitish and very still object suddenly appeared in my headlights. Too late—I hit it. And before I could finish the short question—“What was that?”—I knew. Because a flood of fresh, sulfurous mercaptans assaulted my olfaction. My lone comfort was knowing that the poor skunk was already dead when I hit it. I hope the car stops smelling before I pay off the pipe ­installation.

Rights & Permissions
Share this Article:

Comments

You must sign in or register as a ScientificAmerican.com member to submit a comment.
Scientific American MIND iPad

Give a Gift & Get a Gift - Free!

Give a 1 year subscription as low as $14.99

Subscribe Now >>

X

Email this Article

X