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.
Non-Point Source Pollution. Water Pollution. As water from rainfall and snowmelt flows over and through the landscape, it picks up and carries contaminants from many different sources. This is called Non-Point Source pollution. This polluted water ends up in streams, lakes and the ocean by flowing directly in or by going through untreated storm drains. Water also carries pollutants into underground drinking water as it soaks into the ground. 40% of all lakes and streams are too polluted to use for fishing or swimming in the United States.