Water pollution affects the entire biosphere of plants and organisms living in these water bodies, as well as organisms and plants that might be exposed to the water. The effect can be damaging not only to individual species but also to the natural biological communities. The sources of water pollution can be grouped into point sources, non-point sources and groundwater pollution. Contaminants leading to water pollution include a wide spectrum of chemicals, pathogens, and physical changes such as elevated temperature. Measurement of water pollution is carried out by analyzing water samples with physical, chemical and biological tests. Control of water pollution can be achieved by appropriate wastewater treatment, providing safely managed sanitation services for people who are currently without access, agricultural wastewater treatment, erosion and sediment control from construction sites, and control of urban runoff.