Bio-Sand Water Filters are constructed using metal molds, which forms the poured concrete into a tall, rectangular, standing filter. Once dried and all air bubbles are removed, the filters are removed from their molds and loaded onto a truck to the local villages. When installed on flat ground in someone’s home, larger rocks are poured into the center, then smaller rocks, and then the bio sand. This pattern of rocks and sand is essential. By pouring water through the top, the fine sand removes pollutants and bugs, and as the water trickles further down, the water becomes purified. The pressure from the water pushes it through the tube in the bottom and back out through the top, creating water flow from the spout. The clean water is cooler, and some families use the filter as a sort of refrigeration for meat by storing it on top. The clean water dramatically reduces risk of disease, and only costs about $50 to construct one. Each water filter can last at least twenty years.