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Sewer

Here Are the 3 Most Unusual Things Found in the Sewer

Bar screen: a mechanical filter used to remove large objects, such as rags and plastics, from wastewater.
  • Amelie Hunt

You might want to grab some hand sanitizer before handling cash next time. We caught up with Andrew Clark, Wastewater Operations Superintendent at the Southeast Treatment Plant, who shared that sometimes the sewer has a surprise for us: money.

A $5 bill recently pulled off a screen at the Southeast Treatment Plant.
A $5 bill recently pulled off a screen at the Southeast Treatment Plant.

“Just the other day, one of our screens pulled up a $5 bill,” says Clark.

But that's not the weirdest thing they've found. Since San Francisco's combined sewer system collects and treats both wastewater and stormwater in the same network of pipes, Clark jokes that a better question might be: “What haven't they seen?” Here are some of the wildest, wackiest items that have made their way into our wastewater system:

1. A $100 Bill

That's right - one person's bad luck became someone else's Benjamin.

2. A Dozen Super Bouncy Balls

This one's a classic. At the Oceanside Treatment Plant a while back, a technician checked the fine screen that filters debris only to find super balls bouncing everywhere! A small concrete room soon turned into an arcade, with colorful toy balls ricocheting off the walls before workers finally retrieved them all.

3. A Baby Seal

This might sound like an urban legend, but the story goes that years ago, a live baby seal got swept up through the bar screen during pretreatment. While Clark says that large aquatic animals are an extremely rare spotting in our sewer system, it makes for good conversation around the dinner table.
 

And that's just scratching the surface. In addition to these gems, the San Francisco Public Utilites Commission's (SFPUC) Wastewater team has found tires, construction material, clothing, and of course, the infamous "flushable" wipes. 

Only Flush the 3 Ps

While it's anyone's guess how the seal ended up in the sewer system, Clark reminds us that the biggest culprit behind blockages is non-flushable items like wet wipes. Stick to flushing the 3 Ps: poop, pee, and toilet paper. Anything else? Don't even think about it. Dispose of it properly.

Follow the 3 Ps rule and please, no flushing spare change or bouncy balls - no matter how fun that may seem!