As a Bangladeshi-American entrepreneur, Minhaj Chowdhury has always been aware of arsenic contamination of subterranean water in South Asian countries, especially in India and Bangladesh. After all, it took the life of his grandfather.

The thought of solving the problem always sat at the back of his mind, and is the reason why he chose to major in public health at the Johns Hopkins University in the US.

"I was passionate about solving a crisis that results in one out of every five deaths in Bangladesh alone," Minhaj told The Daily Star in an interview during his recent Dhaka visit.

The death of his grandfather from arsenic-related diseases years ago left a profound impact on the 25-year-old entrepreneur, who is originally from Chittagong.

But it wasn't until July 2011, when he visited Bangladesh as a Fulbright Fellow of the US Department of State, that he felt the clean water crisis was well solvable.

He found that high costs, maintenance requirements and low customer awareness are the reasons why community-based water filtration deployments break down within two years.

Minhaj then came up with a social business model, and co-founded Drinkwell Systems with three others in May 2013.

Social enterprises are businesses patterned after traditional capitalism models but with solutions that seek to address long-term goals such as poverty reduction.

US-based social enterprise Drinkwell transforms arsenic-affected tube-wells into local profitable water enterprises by using proprietary water purification systems and the micro-franchise model.

It uses locally made ion-exchange resins, which look like small beads, to remove heavy metals and chemicals such as arsenic, fluoride and iron. And there is no need for re-mineralising the water as the system retains good minerals.

Drinkwell says it can deliver water 60 times that of a conventional system, and is 17 times energy efficient at half the cost.

Developed by Drinkwell co-founder Arup K SenGupta, the filter is more efficient than the conventional one that uses reverse osmosis, the best practice at present.

Reverse osmosis is a water purification system that has a biological barrier to remove larger particles from water.

The company has a network of entrepreneurs that generate an income by selling clean drinking water.

It selects entrepreneurs by engaging with local prominent persons such as upazila chairmen and imams.

The construction cost of each Drinkwell filter is $8,000-$9,600 (Tk 6.2 lakh-Tk 7.4 lakh), and the chosen entrepreneur can get up to 70 percent of micro-loan to install the system. The entrepreneur then sells 600 litres of water for Tk 100.

Drinkwell provides technical service for each system and charges $0.49-0.59 (Tk 40-Tk 48) per thousand litres.

The company's engineers make unannounced site visits to ensure that the system is kept clean and tidy. They also test the water quality to ensure compliance with World Health Organisation standards.

Drinkwell's activities are mainly concentrated in India, but its filters have been deployed across Laos and Cambodia as well.

The social enterprise has more than 200 profitable deployments around the globe. It recently rolled out its water filtration technology on a pilot basis in Manikganj, with plans to establish additional 10 such tube-wells this year.

And it aims to reach 1 million people in Bangladesh within the next two years.

"By launching an aspirationally-focused social business that is capable of delivering water while creating jobs, I am confident Drinkwell can eradicate Bangladesh's drinking water crisis," said Minhaj.

For his efforts to address the water crisis through a for-profit, social enterprise approach, Minhaj was included in this year's "30 Under 30: Social Entrepreneurs" list of Forbes.

The WHO reports that arsenic contamination of water, which affects more than 200 million people across 70 countries, is the largest mass poisoning in human history.

Arsenic is a colourless, odourless and naturally occurring metal that is found in groundwater in South Asia in dangerously high amounts.

Long-term exposure to high levels of arsenic can lead to arsenicosis, an incurable cancer-causing disease.

Suman.Saha@thedailystar.net