The chemical commonly used to sterilize water is chlorine. Chlorination is a widely employed method in municipal water treatment processes, as chlorine effectively eliminates harmful bacteria, viruses, and other pathogens. It is added to water supplies in controlled amounts to ensure that drinking water is safe and free from contamination. While chlorine is effective, it can also react with organic materials in water to form potentially harmful byproducts, such as trihalomethanes. Therefore, water treatment facilities often monitor and manage chlorine levels carefully, alongside other treatment methods like filtration and UV disinfection, to ensure the safety and quality of drinking water.