Why does water need to be treated to be safe for consumption? Water needs to be treated to be safe for consumption because some places on Earth are not suitable to be drank from. Diseases such as cholera can be found in still water such as lakes and ponds that contain micro-organisms. Also, some pollution can get into water like pesticides or oil, and those substances can be harmful to the human body. Other living organisms also need fresh water. The USGS Water Science School writes,” Clean water is critical to plants and animals that live in water. Migratory birds use water for resting and feeding. Water that has harmful bacteria has to be taken care of. Decaying organic matter and debris can use up oxygen in lakes, causing fish to die off.” Even the economy is affected. The cost of ill health could be lower rates of productivity from sick workers. Paragraph #2: How does a water filter function? First of all, “the process of filtration involves the flow of water through a granular bed of sand or another suitable media, at slow speed” (History of Water Filters). A filter blocks the passageway of unwanted materials, such as living organisms, leaves, and dangerous metals like lead and mercury. Some filters include layers of materials, such as carbon, sand, Tzang 2 and cloth. (Carbon is used for