Microorganisms are microscopic living organisms that are present in water which include bacteria, viruses, fungi, protozoa and algae. While some microorganisms are beneficial to the environment, others can be harmful to human health as in water microorganisms can thrive and multiply rapidly. Therefore, making it important to regularly monitor and treat water sources to ensure that they are safe for consumption as some commonly known waterborne diseases caused by microorganisms include cholera, typhoid fever and dysentery. Proper water treatment methods, such as filtration and disinfection, can effectively remove, reduce or kill harmful microorganisms from water, making it safer and healthier for use.