The kids were all nervously giggling when we arrived at the grates of the wast-water treatment plant. It looked like a weird water theme park. Over several acres of land was a wild collection of lagoons, ponds, fountains, waterfalls, settling tanks, and filtration beds.
We were greeted by Mark, a senior operator. Mark was a roly-poly man with an infectious sense of humor who insisted on referring to sewage as his "bread and butter."
The Bug House
"I'll let you in on a secret," Mark said in a stage whisper, "this whole facility is really a housing complex for billions of happy little waste-eating bugs. We don't treat the waste -- bacteria does. These one-celled critters chomp their way through several hundred tons of poop a day. My job is to keep the bugs happy, well fed, and close to home. Half the plant feeds bugs and the other half kills 'em before we return the water to nature."
I noticed as Mark described the lifecycle of his family of "bugs" that the kids took a few steps back from the edge of the first settling tank. The tank was part of the primary treatment process and works to remove the heavier organic solids from the waste stream. The method is both ingenious and simple -- at least in theory.
Hurried along by gravity or pumps, sewage flows through the narrow pipes at a relatively high velocity. Entering an Olympic sized pool, the speed abruptly drops from several feet per second to a virtual crawl. When the kinetic energy of moving water is dissipated, the heavier particles fall to the bottom.
Sink or Swim
"Here's where we separate the floatie-things from the sinkey-things. Heavy organic solids settle to the bottom of the tank while scum, grease, and lighter objects float to the surface," Mark explained.
"Is that for real?" asked my daughter as she pointed to an official looking No Life Guard on Duty/No Swimming Allowed sign hung from the railing of the tank. Mark just grinned and said, "What do you think?"
As the tour continued, the kids eyes grew wider by the minute and one question followed another. "I never knew poop was so complicated," my daughter said as she snapped scores of pictures.
Some questions worth asking on your waste-water tour:
- Where does the solid stuff go after it's removed from the water?
- What can we do to save water?
- Can recycled water be made safe to drink?
- Are all waste-water treatment plants the same?
- What makes sewage smell so bad?