A startup affiliated with Purdue University in Indiana has developed what it says is a low-cost, low-maintenance slow sand water filter to better provide clean and safe drinking water to schools and communities in developing parts of the world.

Maji Safi International LLC (which means clean water in Swahili) was founded by John Maiyo, a doctoral student in Purdue's College of Engineering. Chad Jafvert, a professor of civil engineering and environmental and ecological engineering; and John Howarter, assistant professor of materials engineering and environmental and ecological engineering, are company advisers.

Maji Safi founder John Maiyo, and company adviser John Howarter The company installs groundwater wells and provides ceramic filters and slow sand filters in western Kenya where safe water is not readily accessible.

The Purdue technology used by Maji Safi uses containers filled with sand and water. At the bottom of the container is a water collection plate designed at Purdue. The sand provides a large surface area on which microbial growth occurs that metabolizes the dissolved and particulate organic material in the water. The point-of-use slow sand filters are made from readily available five-gallon plastic pails or 55-gallon drums.

Once water is treated by a filter, a small amount of chlorine is added to the water for final disinfection, producing clear, colorless, drinkable water. According to the research, after 30 minutes of contact with the chlorine, the water is ready to drink.

Maji Safi has installed 10 slow sand filters in rural schools in Kenya. Jafvert and Howarter have installed similar filters in Colombia, Tanzania, and China.

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Maji Safi International was born out of Purdue's involvement in AMPATH, a consortium of North American academic health centers led by Indiana University, working in partnership with the government of Kenya, to provide access to health care. Technology used by Maji Safi International LLC has been licensed through the Purdue Research Foundation Office of Technology Commercialization.

Initial work on the technology was done through a $40,000 gift from the Kimberly-Clark Corp. The group also received $10,000 from Purdue's Department of Earth, Atmospheric, and Planetary Sciences through an H₂0 grant written by undergraduate students who participated in the research, $10,000 from the Purdue Burton D. Morgan Center for Entrepreneurship, and additional support from AMPATH.

Maji Safi plans to improve the filters based on feedback from the communities and aims to implement filters in 1,000 schools over the next five to 10 years.

The company is also seeking support from people who would like to sponsor one or more schools, which would enable Maji Safi to install filters and provide clean drinking water to the students, teachers, and community members.