Previously, if fluoride, arsenic, manganese, etc. were dissolved in high concentrations in drinking water, there was no other way to consume them or to filter the water using expensive water purification equipment called an RO system. RO equipment provided by many developed countries was no longer used in underdeveloped countries within a year due to high costs and technical difficulties in maintenance. O2NB CO. first began supplying equipment to African villages seven years ago, allowing villagers to manage and operate it, and enabling continuous use by residents in need of water with very low energy consumption and low costs. By installing 1,000 tons/day equipment to remove fluoride contained in spring water and groundwater in the Arusha region of Tanzania, the company is helping 50,000 residents avoid diseases, establishing a sustainable system, educating villagers on technology, and contributing to the creation of a source of revenue.