Water contamination, caused by human activities like industrial discharge, agricultural runoff, and improper waste disposal, introduces harmful substances into water bodies. Pollutants such as pesticides, fertilizers, untreated sewage, toxic chemicals, heavy metals, and plastics degrade water quality, posing significant risks to human health and aquatic life. Major sources include agricultural practices, industrial waste, oil spills, plastic debris, urban runoff, and mining activities, all contributing to unsafe drinking water and ecological damage.