The document discusses various types of water contamination. It defines water contamination as introducing materials that alter the water's quality and make it unsuitable for uses like consumption. Some key contaminants mentioned include household waste water from areas lacking waste disposal systems, which contains detergents, hot water, greases and other materials directly discharged into rivers. Around 74% of all waste water produced comes from households. The conclusion calls for people to stop littering in rivers and stop discharging chemical waste in order to protect water quality for all.