For more than a billion people around the world, finding clean water is a daily concern. Though some technological advances have been made, not all have proven practical. Now, some say a simple clay filter may be the one of the most effective tools.

In Cameroon and Ghana, clay water filters, first produced en masse in 1998 to help victims of hurricanes in Central America, were used to curb the spread of cholera and Guinea Worm.

The discovery of the simple, but successful filtration system could have a major impact on the global water sanitation problem.

“Every 20 seconds a child dies as a result of the abysmal sanitation conditions endured by some 2.6 billion people globally,” UN Secretary General Ban Ki-moon said. In Angola this year, 198 people died in five months from cholera. Diarrhea kills 2.2 million children under the age of five each year. Dysentery, parasites, and other water-borne diseases are also caused by unclean water.

Aid groups are still looking to find the most affordable and adaptable solutions. The clay water filters, while helpful in preventing many diseases, can’t remove arsenic, which is prevalent in East India and other places. Other technologies like Lifestraw—a straw that purifies water as it is drunk—aren’t effective for cleaning large quantities of water.

Educating people on proper hygiene is also a vital part of the equation, as people often dip dirty buckets into clean water tanks.