Issue Definition: Common household products that claim to be ‘flushable” are actually a hazard when introduced into the wastewater treatment system.

Students test the soluble properties of a ‘flushable’ wipe, then develop an action plan to educate others on the impact of these products in the sewer system.

• two small, clear plastic bottles (juice, water, gatorade, etc) [This can also be done using clear plastic cups or small cereal bowls. If you do not use bottles with caps, you will need a stirrer to agitate the water.
• toilet paper squares slightly smaller than a post-it  (Sample A)
• wet wipes squares – same size as toilet paper (Sample B)
  • wipes can be reused between sessions by air-drying if they are still in whole pieces
• small ziploc or other bags to separate the samples

Preparation: Prepare the flushable wipes by rinsing out the soap and let it dry

You may want to begin by talking about  how advertisers often use words that do not give us the full picture, but rather, are designed to persuade us to buy something.  Example: Sugar-Free, Fat-Free, Organic, and FLUSHABLE.

Discuss what ‘flushable’ means. Collect as many ideas as the students suggest. This will set a shared understanding of the term. Does it just mean it can be flushed? What do they think makes something flushable? A common thought is ‘out of sight, out of mind;’ If it is gone, it is gone.

Introduce the terms soluble and insoluble. Create a T chart to have students list examples of each.

Explore

Before handing out materials, review the steps of the flushable test with the students.

•  It is important that students are able to distinguish between the two samples (toilet paper (A) and wipes (B)). Wipes may be marked with a marker to help students keep track of which is which.
• Using two clear plastic bottles, have students label the bottles, A and B
• Bottles should be filled half-way with tap water

Once materials have been distributed, ask the students to feel the materials and discuss their characteristics (texture, thickness, etc).

Have students hypothesize which they think is the flushable wipe. What evidence can they provide to support their claim?

Review the steps of the test before beginning.

Review again what they are ‘looking for’ to consider something dissolved. How many fragments, size of fragments?

Students may want to measure how long it takes for the samples to dissolve.

Follow the steps on the slide deck to conduct the test.

• Students place toilet paper in bottle A and the wipe in bottle B.
  • Don’t tear up the flushable wipe since they don’t tear them in practice.
• Agitate each bottle gently for at least a minute.
• Let the samples rest to settle for a time (which mimics the water treatment plant)
• Make observations on what happened to each sample – did they break up while stirring, are they intact, did they dissolve partially or in whole? Use what was observed to determine which piece was toilet paper or a wipe.

Explain

Facilitate a discussion to share observations and come to some conclusions about what they saw.

Revisit the adjective – flushable. What does it actually mean? Do our findings support the claim that something that is flushable IS really flushable?

Upper Grade/HS Students – explore the types of polymers that make up toilet paper and wipes, and what instruments we use to identify them. Career connection – Materials Science

Students will suggest what happens to the wipes once they enter the sewer system.

The plastics in the wipes travel through the system and combine with other elements in the pipes that make it difficult to keep the water system moving the way it should.

Action project – What can students do to inform people about the proper way to dispose of ‘flushable’ wipes.

Focus on the cumulative problem – have the students combine the liquid from their tests through a sieve to see how the flushable liquid collects to form a larger blob of flushable wipe fragments.

Clean-up: How to clean up?  We don’t want to put the “wipes” detritus down the drain!!!  We put the wipes detritus on a plate to throw away