The Flushing

Download the Video Teaching Guide PDF/Word

Main Topic of Video: Water conservation can start at home with the detection of leaky toilets.






  1. Brainstorm the ways in which you use water in your home.
  2. How do you use water at school?
  3. What home activity uses the most water on a daily basis? How about at school?
  4. Why is water conservation an environmental issue?
  5. What have you heard about water in your state in the news? How about in the world?
  6. Do you currently take any actions to conserve water usage in your home or classroom?


  1. As you watch the video, pay attention to the changes in the appearance of the toilet monster.
  2. What awakens the sleeping couple?
  3. What is the purpose of the water dye tablet?
  4. What is “phantom flushing”?
  5. What causes phantom flushing? How is it fixed?


  1. Have you ever experienced phantom flushing in your home or school?
  2. How can low-flow toilets lessen the impact of phantom flushing?
  3. Do you need to flush the toilet every time you use the bathroom? Why or why not?
  4. What are some personal actions you can take to use less water in your daily life?





  1. Students should come up with activities such as bathing, brushing their teeth, cooking, using the bathroom, washing hands, washing machines, watering the lawn, using swimming pools, and others.
  1. Students might use water in schools for flushing the toilet, washing hands, science labs, and other endeavors.
  1. From the EPA Water Sense Program: The average family of four uses 400 gallons of water a day, with most of it consumed in the bathroom.


This infographic on the Water Sense webpage breaks down home water usage (original data cited below image)


The following infographic from EPA water sense depicts the differences in water usage between schools and other types of facilities.



  1. Water conservation is an environmental issue because approximately 2.5% of the water on our planet is fresh water. Of that, less than 1% is on the surface of the planet (the rest is frozen in glaciers/ice or underground). Here is a brief summary of the fresh water crisis from National Geographic’s page on the fresh water crisis.

“Due to geography, climate, engineering, regulation, and competition for resources, some regions seem relatively flush with freshwater, while others face drought and debilitating pollution. In much of the developing world, clean water is either hard to come by or a commodity that requires laborious work or significant currency to obtain.

Wherever they are, people need water to survive. Not only is the human body 60 percent water, the resource is also essential for producing food, clothing, and computers, moving our waste stream, and keeping us and the environment healthy.

Unfortunately, humans have proved to be inefficient water users. (The average hamburger takes 2,400 liters, or 630 gallons, of water to produce, and many water-intensive crops, such as cotton, are grown in arid regions.)

According to the United Nations, water use has grown at more than twice the rate of population increase in the last century. By 2025, an estimated 1.8 billion people will live in areas plagued by water scarcity, with two-thirds of the world’s population living in water-stressed regions as a result of use, growth, and climate change.”

  1. Answers will vary. For the latest news surrounding water issues, do a quick google news search for water contamination, drought, water shortages, etc. before class.
  1. Answers will vary. Some students might take 5 minute showers, while others might turn off the faucet when brushing their teeth. 


  1. In the beginning, it was blue and contained in the toilet, then it became more agitated and partially out of the toilet. When the dye was added, it became green (because the dye leaked from the tank) and angry (because the leak had been discovered and the leaky valve was replaced). In the end, it was more docile and left wet footprints on the ground as it left the toilet and house. 
  1. Flushing sounds coming from the bathroom.
  1. It can tell you whether or not water from the tank is leaking into the toilet bowl.
  1. When water from the tank leaks out to the bowl, causing the toilet to constantly refill.
  1. Phantom flushing is caused by a broken flapper valve and can only be fixed by replacing the valve. 


  1. Answers will vary depending on experience.
  1. Low flow toilets are those which use no more than 1.6 gallons of water per flush (as opposed to the previous standard of 3.5 gallons/flush). If phantom flushing occurs with low flow toilets, there will be less water wasted as compared to traditional toilets.
  1. This is a personal question that will vary depending on student, grade-level, experience, etc. In times of drought, some people choose to not flush the toilet if there is no solid matter present. This article from SFGate discusses the debate over this personal choice.
  1. Answers will vary. Some students might save shower water to use for watering outdoor plants. Others might skip or reduce car washing.



The topic of water usage easily lends itself to quantitative practice. Have students calculate the water usage described in the following prompts:


If low-flow toilets use 1.6 gallons of water per flush and you flush the toilet 6 times a day, what is your daily toilet water usage?


What was your daily water usage in toilets without a low-flow toilet (assume it uses 3.5 gallons per flush)?


The water footprint network has many resources for exploration. Among them are a simple water footprint calculator that takes into consideration food habits, income, gender and country of residence.

National Geographic also has a nice online water footprint calculator.

Students can also complete a more detailed water inventory to take stock of their water usage. The Springs Preserve in NV has a nice water inventory activity that can be printed out.

The USGS water science school has more information (data, graphs) about water usage.

TED-Ed has a nice two part video series on freshwater—part 1 summarizes where we get our fresh water, while part 2 summarizes the issue of fresh water scarcity. The TED-Ed website has discussion questions that can follow each short video.

(part 1)

(part 2)

The National Center for Case Study Teaching in Science has a reading on the privatization of water in Bolivia—it’s a good introduction to the social justice and government issues inherent in providing water for a population.




Here is an Op-Ed from the LA Times on phantom flushing (May 2015).

A short video that illustrates how toilets work.

Another Green Ninja Show episode about another way to conserve water.


Credit: This teacher resource has been adapted from content originally developed by Lee Pruett.

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