If you’re like most, the gross factor keeps you from looking too closely at sewer facts. But don’t hold back your curiosity. The sewage treatment world is full of interesting trivia, from when the first sewers were invented to how we use sewage now (once we’ve made it safe again.) We’ll share our best sewer trivia below.

1. Sewers Were Invented in 600 BC

The Romans are well-known for inventing aqueducts, a way of bringing in new freshwater to a city. Of course, then they also had to develop a way to get all of that extra human waste out of the city. They installed the first sewer line in 600 BC. At first, it was just a canal, but the clever Romans soon realized they should cover the canal and extend it underground to reduce the smell of the wastewater.

2. A Bacteria that Treats Sewage is Also in Your Corn

It’s also in your gastrointestinal tract. Bacillus subtilis is an endlessly useful bacteria that humans have used for all sorts of purposes. You can find B. subtilis in the ground, and in the digestive tracts of animals that eat grass. It is used on an industrial scale to treat human waste and even waste from nuclear power plants. In 2011, part of the bacteria’s DNA was added to a strain of corn, to help it resist cold shock from early frosts.

B. subtilis has also been used:

  • To treat stomach aches before we had antibiotics
  • For space research
  • To boost the growth of saffron
  • To prevent a specific fungus’ growth
  • For fermenting proteins and foods
  • To make phosphorous more bio-available in soils

3. Photographers are Fascinated with Manholes

Just search #ManholeMonday on Twitter, and you’ll find months of unique manholes from all over the world. According to the Chicago Sun Times, the hashtag got started when a group of Chicago manhole enthusiasts started sharing their best pictures on Twitter.

Manholes are more interesting than you may imagine, as dozens of unique posts reveal every Monday. The photos reveal manhole covers with uplifting messages in Scotland, historic manhole covers in Rome, and artistic manhole covers from Japan.

4. Many Sewer Back-Ups Are Caused By Fatbergs

In major cities, the sewer system sometimes can’t handle the amount of fat we pour down the drain. That fat can collect together to form what waste treatment authorities call fatbergs. In fact, in New York City, 71 percent of sewage back-ups are caused by a fatberg closing off the line. We now use systems that capture fats and grease before it can clump together, but it doesn’t always work.

5. Your Sewage can be Used as Fertilizer

As we treat sewage we remove liquids, or wastewater, and end up with sewer sludge. After several different treatments, the sludge is transformed into “biosolids” that act as safe and nutrient-rich fertilizer for farms. If we didn’t treat sludge and use it as fertilizer, our other options would be to dispose of it in a landfill or incinerate it. So, we’re quite lucky we’ve figured out how to make it useful and safe.

That’s all of the sewage facts we have for you today. But you can learn more by browsing our blog.