A novel way to purify water

An interview with Francesca O'Hanlon, founder of Blue Tap

This year’s World Water Day on 22 March celebrates water for all.

It is a human right to have access—without discrimination—to sufficient, safe, physically accessible and affordable water for personal and domestic use.  

Yet billions of people around the world still do not have access to safely managed drinking water. Contaminated water can transmit a variety of diseases, such as diarrhoea, cholera, dysentery, typhoid and polio. Innovations around water safety and quality are therefore crucial to human health.

 “Water pollution and deteriorating water quality are leading environmental problems facing our water resources all over the world,” said Lis Mullin Bernhardt, UN Environment’s Programme Officer for Fresh Water.

“The resulting toll it takes on human and ecosystem health is considerable. Finding inexpensive, low-tech solutions to improve water safety in homes would be an important step in the right direction.”

In 2016, 29-year-old Francesca O'Hanlon founded Blue Tap, a social enterprise that uses 3D printing to provide household water purifying solutions for users in developing countries. The 3D-printed chlorine injector is designed to automatically inject chlorine into household-level water systems, enabling high-quality drinking water in low-resource settings.

We talked to O’Hanlon about her work and what it takes to be an environmental entrepreneur.

What inspired you to start Blue Tap?

I was building a chlorine injector for Engineers Without Borders in Mexico. They found that their customers were not drinking the water as much as the organization wanted to, because the chlorine tablets would not disperse properly, meaning that some cups of water were highly chlorinated, and others not at all. My task was to work on designing a chlorine injector. I then set the project aside and went back to university to study for a master’s degree. After that, I worked with Doctors Without Borders, where I spent one year working in South Sudan and six months in Central Africa Republic, providing water and sanitation to displaced populations. I was responsible for ordering a chlorine injector, but the cost was extortionate—around US$1,600. When I started studying for my PhD, I started exploring the idea of developing a low-cost chlorine injector using 3D printing.

What is Blue Tap’s business model?

After having tested the design in the lab in 2016, we went to Uganda to do some field trials. We wanted to implement a development project in a different way; rather than selling or donating the injector straight to the end user, we set ourselves up as a community interest company. We sell the chlorine injector for US$33 to local plumbers and they get training on chlorination and managing their business. The plumbers then sell it on to the beneficiaries along with their service for around US$53. This not only helps plumbers to improve their income, but it also means that there is always someone in country who is managing the chlorine injectors.

Why is a chlorine injector better than other mechanisms of water purification?

A lot of contamination happens when people store water in dirty containers and chlorine is the only form of purification that protects water that is in storage.

Why did you decide to use 3D-printing to produce chlorine injectors?

When I was a student at the engineering department at Cambridge University, they had just bought 3D-printers which were very fashionable at the time. It has been amazing for us, because it is a fantastic technology to prototype. You can design a chlorine injector, send it to print and six hours later you can test it in the lab—we could therefore assess the effect of making changes in the design very quickly. Without 3D printers our project would have taken 2–3 years longer and by being affiliated with a university, we basically had no expenses.

What advice can you give people who want to found their own start-up?

I would recommend partnering up with people who have different skill sets. For Blue Tap, it was crucial to have someone who has a detailed understanding of technology, someone with a business mindset, and someone with a development background. Also, find people you get along with—it makes it so much easier to work as a team.

Do you have what it takes to invent the future? Our Young Champions of the Earth prize, powered by Covestro, is open until 31 March. Apply now!