The non point sources are polluants that indirectly find their way to the ocean, most of the time because of rain or ground water. This type of pollution is the result of Urban street, suburbia, homes and mainly the agriculture. But other activities has negative impacts on the water quality such as mining, road salt, the spills, the sewers because they can find their way in the ground. These activities pollutes the water in the Ocean, rivers, lake but also and mostly the ground water. Agriculture is an huge issue in the water pollution process. Fertilizers, salts, pesticides and sediments make their way until the ground water and can have an impact on the water in which they come into contact. But Asia is a huge populated region and people need food so what can we do about agriculture ? If we stop to use fertilizer and pesticides there will be less food but peoples need food, that is why it's hard to stop the water pollution. In addition the phosphate and nitrate who run into the lakes provoke a multiplication of algae. The algae grow very fast because of the fertilizers of agricultures and then block the light from reaching underwater causing massive amounts of body death. This can touch the groundwater and make the things worse.
Many sites in South Asia are contaminated with dangerously-high levels of arsenic. The long-term exposure of this amount levels of arsenic in drinking-water reduce child survival and lead to cognitive impairment. He also provoke cardiovascular disease and cancer. It's important to continue the interventions in order to improve water quality.