The document discusses various types of water pollution including point source pollution from direct discharge into waterways, non-point source pollution from runoff, thermal pollution from industrial cooling water, organic pollution from excess organic waste, ecological pollution from natural events, and toxic pollution from chemicals. Specific examples of issues discussed include water pollution in the Pasig River in the Philippines, pollution of surface water sources in the United States, and the potential for subsurface oceans on Jupiter's moons Europa and Ganymede.