Sand, anthracite or activated carbon filters refine the water stream, removing smaller particulate matter. alum, ferric chloride) destabilizes the particle charges and prepares them for clarification either by settling or floating out of the water stream. Clarification refers to the separation of particles (dirt, organic matter, etc.) from the water stream. Traditional surface water treatment plants generally consists of three steps: clarification, filtration and disinfection. Water purification usually occurs close to the final delivery points to reduce pumping costs and the chances of the water becoming contaminated after treatment. Water treatment must occur before the product reaches the consumer and afterwards (when it is discharged again). Virtually all large systems must treat the water a fact that is tightly regulated by global, state and federal agencies, such as the World Health Organization (WHO) or the United States Environmental Protection Agency (EPA). The raw water is transferred to the water purification facilities using uncovered aquedu cts, covered tunnels or underground water pipes. Raw water (untreated) is colWDWEDWEFGWERFGEElec LKDFLOPIEJTFIJQWEOFKWP RJFE[Q'EPDLKWPEOJPQ ODPWIRJFOLEJRFWīold te xt ted from a surface water source (such as an intake on a lake or a river) or from a groundwater source (such as a water well drawing from an underground aquifer) within the watershed that provides the water resource. Water abstraction and raw water transfer 1 Water abstraction and raw water transfer.Water supply networks are often run by public utilities of the water industry. Connections to the sewers (underground pipes, or aboveground ditches in some developing countries) are generally found downstream of the water consumers, but the sewer system is considered to be a separate system, rather than part of the water supply system.A pipe network for distribution of water to consumers (which may be private houses or industrial, commercial, or institution establishments) and other usage points (such as fire hydrants).Additional water pressurizing components such as pumping stations may need to be situated at the outlet of underground or aboveground reservoirs or cisterns (if gravity flow is impractical).Tall buildings may also need to store water locally in pressure vessels in order for the water to reach the upper floors. Smaller water systems may store the water in cisterns or pressure vessels. Water storage facilities such as reservoirs, water tanks, or water towers.Treated water is transferred using water pipes (usually underground). Raw water may be transferred using uncovered ground-level aqueducts, covered tunnels, or underground water pipes to water purification facilities. A raw water collection point (above or below ground) where the water accumulates, such as a lake, a river, or groundwater from an underground aquifer.A drainage basin (see water purification – sources of drinking water).A water supply system typically includes the following: A water supply network or water supply system is a system of engineered hydrologic and hydraulic components that provide water supply.