There’s no question that clean water is a necessity. Access to clean water decreases water-borne illness, makes life safer, especially for women and girls, and potentially increases national income. Widespread access to clean water can be a game-changer in developing countries, especially in the wake of the COVID-19 pandemic when sanitation practices are more critical than ever. 

Ensuring clean water for everyone is a complex issue. While governments and large nonprofit organizations work on developing major systems to make clean water available throughout the world, steps are being taken to end the harshest realities of the water crisis with options that bring faster relief. One of those solutions is BioSand filters (BSF) which provide an inexpensive and sustainable opportunity for clean water.

Invented by Dr. David Manz of the University of Calgary, the BSF enables Thirst Relief International to deliver clean water to places where it’s needed most for very little money. 


How the BioSand Filter Works

The BSF was designed to be as low-maintenance and affordable as possible, and it requires neither heat nor electricity (another scarcity in developing countries) to purify water. Instead, the BSF model is based on the natural process by which the earth filters the water, which includes 4 discrete filtration processes. These processes occur in combination with one another, rather than in prolonged sequence: 

  • Biological Filtration – The top two centimeters of the filter are made up of a fine sand, which captures and retains beneficial microorganisms that create their own food chain, consuming harmful parasites in the water. This is called the “biological layer”
  • Mechanical Trapping – The water continues through a deeper layer of fine sand, which traps harmful organisms between the grains. This is referred to as “mechanical trapping” or “mechanical filtration”
  • Adsorption – The fine sand also creates a static charge between grains, causing even more organisms to stick to each one, a process known as adsorption
  • Natural Death – The physical depth of the filtering sand reaches about 3 feet, allowing very little light and oxygen to reach the bottom. This produces the fourth filtration process, “natural death.” The harmful parasites that do not get stuck within the sand are starved for light and oxygen, rendered harmless as they die naturally


The filtered water produced by the BSF is free of up to 100 percent of worms and protozoa, 98.5 percent of bacteria, and 99 percent of viruses. Additionally, the BSF cools water as it filters, which can be essential in regions of water scarcity, as many have blisteringly hot climates. 

This specific filtration process also allows water to retain naturally found minerals that can offer health benefits. Due to these unique elements of the BSF filtration process, the water produced is also known to taste better than boiled water–another common, though energy-heavy, method of purification.

Most importantly, BioSand Filters present a more sustainable and inexpensive option than many other filtration systems. They are durable and easy to use, with a high yield rate and relatively little required maintenance. Due to its simple design, local community members can undertake repairs with minimal training. 

Further, replacement materials for the BSF are readily available within most nations, meaning that they are much less likely to be subject to taxes or bribery issues that affect many imported materials, and sourcing and delivery are likely to be easier. 

The up-front cost of the BSF is also minimal. For example, a BioSand Filter model can cost as little as $100, a price that includes manufacturing and delivering the filter and training community members to use and repair it. These filters can provide clean water for more than 10 people for up to 30 years. Broken down, that means clean water for one individual costs about 2.7 cents per month—making the BSF possibly the most economical option for clean water in the industry. Since clean water relief efforts are still largely reliant on donor funds, that level of cost-effectiveness is incredibly valuable.


Forward to a More Filtered Future

There are so many ways you can help Thirst Relief International’s mission to make clean water accessible. Whether you make a cash donation, create a fundraising event, participate in an existing fundraiser, or just share the message with friends, family, and associates, your support can serve whole communities! With the ability to offer clean water, it’s never been so easy to use your power to save lives!