The document discusses various types and causes of water pollution resulting from human activities. It outlines different pollutants like oxygen-depleting wastes, plant nutrients, chemicals, sediments, radioactive isotopes, thermal pollution and oil that can pollute water. Specific causes mentioned include mining, agriculture, deforestation, oil spills, industrial waste, and nuclear energy. The impacts of water pollution include reduced oxygen in water, algal blooms, spread of diseases and eutrophication. Proper waste water treatment, sustainable practices, and pollution prevention are recommended to address the issue.