River Quest 2016
Next week is the 24th annual St. Louis River Quest, a field-day experience that brings 1500 area sixth graders to the St. Louis River to cruise and learn from industries, agencies, and nonprofits about the interconnected nature of ecological, industrial and commercial aspects of the estuary. The event happens over four days aboard the Vista Star and the Duluth Entertainment & Convention Center. Students visit 12 learning stations on this half-day adventure.
WLSSD’s station provides a quick “Wastewater 101” for our sixth grade friends. Staff describe the treatment process with the help of a plethora of props and a little bit of humor. Our goal, in about 10 minute’s time, is to describe WLSSD’s role in the community as the wastewater authority and demonstrate how dirty water is cleaned at the wastewater treatment plant.
We all make dirty water every day. Brushing our teeth, flushing, washing clothes, and showering all contribute to the 40 million gallons that WLSSD treats daily, and lucky for us, our sweet and bright sixth graders are particularly keyed-in to personal hygiene and inferred potty jokes!
The Giant Microbe stuffy we employ during River Quest; it’s an E. Coli but it’s still lovable.
The session begins with the selection of a student scientist from each small group. Festooned with personal protective equipment including gloves, a lab coat, and safety glasses, and guided by a WLSSD staffer, the student extracts a drop of sewage sludge from a sample bottle. The drop is placed onto a slide and the student readies it for the light microscope.
In the meantime, another WLSSD staff is describing to the larger group the travel of dirty water through pipes and engineered systems to the wastewater treatment plant, where trash is removed and bacteria are introduced to the wastewater. The bacteria are given unlimited oxygen that they use to digest the nutrients (the “waste”). This echoes the naturally-occurring process in the river as wastes are decomposed by resident decomposers, including macro and microorganisms. After a short time spent eating, the bacteria settle down into the bottom of tanks and the clean water floats to the top. It is filtered and then returned to the river.
The grand finale of session comes with the dramatic reveal of the critters that clean our wastewater! A camera attached to the light microscope beams a live shot of the “critters” onto a large screen. We can’t see bacteria, who are so tiny specialized equipment is necessary, but we can see single-celled organisms that eat the bacteria and other solids.
Image of stalked ciliates common the activated sludge of the wastewater treatment plant.
Sixth graders are typically amazed and revolted at the same time, and we remain delighted to share the simple, but important role, of wastewater treatment in making our community a safe and beautiful place to live.