If you add the valences of each atom in the molecular formula for arsenious acid, H 3 AsO 3, you can see that the molecule, which is uncharged, has a total valence state of 0 (3x(+1) for the hydrogen atoms; 1x(+3) for the arsenic(III) atom; 3x(-2) for the oxygen atoms = 3+3-6 = 0).
Eighty percent of sewage in India is untreated and flows directly into the nation's rivers, polluting the main sources of drinking water, a study by an environment watchdog showed Tuesday.
Two Sources of Water Pollution. Though water pollution may occur from a variety of sources, there are two terms used to describe how the water became polluted. When water is polluted from point sources, this is pollution from a discrete location.This discrete location could be a factory, a sewer pipe or a runoff from a single farm.ollution may be caused by natural sources or human activities, but regardless of the cause, the result is the same. It can have detrimental effects on aquatic ecosystems as well as the health of those who depend on those sources of water, like us!