This article is a continuation of our series about various topics in renewable energy. Water from public sources may appear to be clean, fresh and safe to drink, but that is not always the case.  In many large lakes and other bodies of water, there exists vast breeding of bacteria and pathogens. Even running water, which appears to be pure, may have animal waste, sewage or industrial waste in it. The effects can be seen from the plants (water cress) growing near the banks of the river or lake. Behind the scenes of many pools, zoos, parks, cities and towns, are portable water filtration units that keep the environment safe for people and animals. This is not an easy task as it may seem for there is more to keeping swimming pools than just throwing in volumes and volumes of chlorine. The water has to be filtered constantly and used again in order to keep it always fresh, clean and to prevent diseases from breaking out. Research and high technology processes are applied to ensure water in any community is safe and meets appropriate clean and potable water standards. Modular water filtration devices are made in various different ways for many applications. These can be used to utilize different kinds of mediums in order to remove the bacteria from the water for drinking, bathing and swimming. Water sources in the community are filled with contaminants, like human and animal waste, mining sludge, and industrial wastes. It is human’s responsibility to clean up the mess it made, so it can leave a better world for the next generations to come. Portable or modular, as well as permanent water filtration devices and units can be used in various applications to clean and purify the water that is otherwise unsafe to use. Modular water filtration systems are very important during emergency cases like in natural disasters such as torrential downpours, earthquakes, landslides, flooding, mudslides, typhoons and political dilemmas. Flooding adversely affect water treatment plants and can contaminate available water resources. In times like these, modular water filtration systems can make an instant source of clean potable water for people to use for cooking, drinking and bathing. Companies and manufacturers of modular or portable water filtration devices can set these units up and delivered within short periods of time. Whenever and wherever there is an immediate need for fresh and clean or potable water, water filtration devices can be rented too. It is wonderful to know that there will be no situations where people in developed countries have to sacrifice to make use of water full of bacteria. It is also nice if the whole world would have the same access to clean and safe water. Clean and safe water can stop major world problems like poverty, diseases, and premature deaths. It is not feasible for a community to be productive and show development and progress if they can’t meet even the most basic needs of its people. It is important that water filtration be introduced to help them improve their quality of life.