A dual water toilet flushing system to recycle shower water.

Solution Name

A dual water toilet flushing system to recycle shower water.

One-line solution summary.

A dual water toilet flushing system, called Arya, and a method to recycle the shower water to toilet is my solution. This was installed and tested in my home.

Elevator pitch

What is your solution?

My invention is a solution to conserve the clean water used for toilet flushing by substituting it with the used water (called grey water) from the shower.  I have developed a dual water toilet flushing system that can use both fresh water and grey water so that there will not be any interruptions if the grey water is unavailable.  In order to make it universally usable, I designed it without any need for electricity for switching between fresh and grey water as long as the grey water is available at a pressure similar to the city water supply.  To demonstrate its efficacy, I modified the shower basin in a single family home to automatically collect water,  purity it, and to store it in a tank.  I used a simple micron filter and used this system with a regular blow down of the tank every 48 hours. I have designed a simple technique to use an inch difference between the shower basin and the bathroom floor with a sump pump to transfer the water to a tank. An automatic pressurizing pump  transfers the grey water from tank to toilet.

What specific problem are you trying to solve?

A simple way to conserve nearly 25% of domestic clean water usage across the world is to redirect the used shower water (grey water) for toilet flushing.  I am creating a product to enable every home in the world to save water by using grey water instead of fresh water. Libya, Western Sahara, Yemen, Djibouti, and Jordan are top five countries with sever water shortages. The global water crisis is a human problem rather than a series of isolated geographical inconveniences as water is the most important economic source in view of how green hydrogen from electrolysis is picking at a fast pace.  The idea of shower water to toilet may be simple, but no one is doing it because an economical and robust commercial technology does not exist.  Grey water is essentially dirty water that one has to clean and reuse it.  It is a substitution for fresh water for a good cause and the solution can never compromise normal life.  As inventors, we cannot ignore this important aspect and I envisioned a toilet flushing system that simply has to switch back to fresh water without any valve opening or closing manually.  I am targeting the entire world community including developed countries because the water scarcity need to be considered as an anticipated problem of the world.  The water recycling problem is being overlooked due to lack of a good solution. 

Who does your solution serve? In what ways will the solution impact their lives?

My solution serves the world community to address water scarcity where needed.  When a robust solution like mine is implemented, people don't have to take shower in a bucket like they do in many localities.  The solution that  I have implemented is well tested, but not productized yet. The objective of my solution is to make sure that the use of shower water in a toilet is done to save a lot of fresh water and at the same time it is done in a hygienic way so that it becomes a standard practice and part of regular plumbing in every home.  Middle class community is major part of the world population and my solution targets that community faced with water shortage that they fight to manage every day.  In typical apartment homes with average 10-20 families,   shower water collection and reuse in toilet trials have failed because of complaints arising from   supply interruptions.  Instead of all or nothing type of grey water reuse methods,  use when available approach gives them a workable solution that can improve with time.  The rationed fresh water availability is very common in developed countries and the water saving potential guaranteed by my solution can significantly relieve them from the water related stress.  Developed countries can act ahead of serious future water scarcity issues by designing homes with my solution without worrying about if one will use it or not.   

What steps have you taken to understand the needs of the population you want to serve?

I wrote to several organizations in India to understand the requirement and problems they face in grey water recycling.  I chose India because it represents well in water related issues that affects the community.  I interviewed apartment owners and read several review articles.  Some of the case studies from Malaysia on grey water recycling helped me understand the troubles they face in spite of several efforts by the city and municipality.    I worked with 3M and Discovery education and the original work of mine started with participating in an Young Scientist Challenge sponsored by these two organizations.  I am a member of Water Environment Federation and I represented Texas in the national competition of Stockholm Water Junior Water Price.  Currently, I am in the process of engaging California Water recycle research organization for helping me with the productizing my solution.  I talked to Sugarland Mayor and city officials to understand Texas state requirements before I installed the solution in my home.  

Which aspects of the Challenge does your solution most closely address?

Other: Addressing an unmet social, environmental, or economic need not covered in the four dimensions above

What is the unmet need that your solution tried to address? Why is it important?

Grey water recycling from shower to toilet to save fresh water is the unmet need due to lack of a simple solution to do so.  In my view, use of fresh water for toilet flushing is serious mistake.  Use of least polluted shower water for toilet flushing after a simple purification step is a straightforward solution.  It is more important than ever to save fresh water because water is going to be the main feedstock for hydrogen via electrolysis using renewable energy.  We cannot waste water at all.  The cost of water will increase and it will definitely start impacting the economy in many ways.  Most commercial grey water purification solutions today go to an extreme side to purify the grey water to a greater level by expending a lot of energy and it is unnecessary.  Shower water is not pure and it is well understood.  But, to use it in a toilet simple micron filter is enough with regular blowdown of the tank.  However, my dual water toiler flushing system is the main equipment required that does not call for 100% purification of the grey water.  Fresh water and grey water are two independent water circuits and this is the key element of the overall solution with the dual water toilet flushing system.  It is important because switching between fresh and grey water for essential use equipment such as toilet flushing is not the right approach.  

Our solution's stage of development:

Explain why you selected this stage of development for your solution—in other words, what have you accomplished to date?

I have developed a dual water toilet flushing system and presented  the solution to a group of scientists at 3M and Discovery Education and received 2nd Price in the national level, which proved my idea to be well accepted by the scientific community.  I, then installed it in my home with the shower water recycling methodology and presented in the Stockholm Junior Water Price national competition and received innovator award, which proved my recycling methodology to be a true solution to the problem.  The arrangement I have is being visited my several people in my community for their verification and enquiry.  I am currently a high school senior and Covid has impacted my plans to productize it, but I have been contacting the state of Massachusetts and the state of California for Sponsoring my roll out including commercial productizing.  What I have is a Pilot plant in my home, which is in service since I commissioned it and I never had a single issue.  

Where our solution team is headquartered or located:

Team Lead:

Mehaa Raja Amirthalingam