To Flush or Not To Flush

By Mieka Myhre
Elementary Category (Grades 4-6)
Experiment | Environment

I did this experiment because we were having a lot of toilet clogging. I started thinking, “what if the “flushable” wipes that we put down the toilet are causing the problem by not breaking down fast enough to not clog the toilet?” I wanted to find out which brand of wipes are most flushable so that we could stop having toilet problems, and which brands break down the fastest. This experiment matters because:

  • There is a new sewage treatment plant being built in Victoria and we should know if wipes will cause sewage problems or clog the filters;
  • Fat burgs, which are wipes stuck together with fat, clog the sewer systems;
  • If we know which wipes break down fastest we can choose to buy those brands so we won’t have sewage problems; and,
  • We should know if the products we use are environmentally friendly so we can protect the animals and plants.

There is no standard way to decide if a wipe is flushable. Manufacturers don’t use the same tests or check if their products will cause problems in the sewers and treatment plants. For my experiment I defined flushable to mean that a wipe will go down the toilet when flushed and break down to less than 7.5 centimeters which is the size of standard sewage pipes in our homes.

My hypothesis is that Cottonelle flushable wipes will break down the fastest because the Cottonelle website says that the wipes are made of cellulose which is a material made of plant walls that breaks down quickly.

To test this I compared different brands of flushable wipes (variable) with each other and with toilet paper (control) by putting one wipe or two squares of toilet paper into jars of water, shaking them periodically and observing how much they broke down. I waited for a certain amount of time after every shaking and then repeated the process. I made observations after each shaking.

I made a 15 point scale and converted the observations into numbers and graphed the results. Level 12 and above is where wipes are considered flushable. Level 15 is the most the toilet paper broke down. Level 13 is the most any of the wipes could break down. My results show that flushable wipes take at least 4 hours and 15 minutes to disintegrate compared to toilet paper which broke down in just 15 minutes. All the wipes can go down the toilet but only 3 brands broke down to 7.5 cm pieces.

According to these results my hypothesis was correct. Cottonelle flushable wipes broke down to level 12 in 4 hours and 15 minutes, 17 times longer than toilet paper. This is faster than the other brands I tested which took 6 hours and 15 minutes or 25 times longer than toilet paper. Out of the five brands tested, three were flushable and two brands were not.

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