Water supply (multipurpose)
Water supply means supply of surface or ground water to water users in the amount required and in accordance with target values for water quality in water bodies.
Water is used by different users for most diverse purposes. However, the large majority of these uses can be broken down into the following major categories:
- use for domestic and drinking purposes (drinking, cooking, washing, laundering, housekeeping, etc.);
- use for industrial purposes (by industry, transportation industry, energy sector, agriculture, etc.).
There are centralized and decentralized water supply systems.
Centralized water supply system supplies water to several water draw-off points by arranging a water pipeline represented by a complex of engineering facilities by means of which water is withdrawn from the water supply system, treated as needed to improve its quality to meet the water user’s requirements, delivered to the area of consumption, and distributed among water consumers. The quality of drinking water shall be regulated by the State Standard (GOST). Centralized water supply is organized on surface or underground sources.
With decentralized, local, water supply system water is drawn-off by population directly from the water source without distribution network. Groundwater use most often used a water supply source; open (shaft) wells or spring catchments serve as water intakes. Sanitary regulations allow using well water for drinking if its coliform index is 10 or below; turbidity according to the standard scale is 1.5 mg/l or below; clarity (according to the Snellen font) is 30 cm or higher; color index is not higher than 30°. The other indices of chemical composition and organoleptic properties of well water must meet GOST “Drinking water” requirements.
The water supply system is a complex of structures designed to provide a certain group of water consumers (on a certain site) with water in the amount required and of the quality required. In addition, the water supply system must have a certain degree of reliability, i.e. ensure water supply to consumers without inadmissible lowering their own performance measures in relation to the quality and quantity of the water supplied (e.g. intermission in or lower water supply, or deterioration of its quality to intolerable values are inadmissible). The system of water supply (to human settlement or industry) is to ensure water withdrawal from natural sources, its treatment, if required by consumers’ requirements, and delivery to areas of consumption. This is accomplished by means of the following structures which generally are parts of the water supply system:
- water intake structures by using which water is received from natural sources;
- water-lifting structures, i.e. pumping stations that pump water to the sites of its treatment, storage, and consumption;
- water treatment facilities;
- water conduits and water supply lines that used to transport and deliver water to the areas of consumption of it;
- towers and reservoirs used as regulating reservoirs and storage basins within the water supply system.
According to water supply method:
- gravity;
- with mechanized water supply (by means of pumps);
- by zones (by gravity to some areas and by using pumps to others);
According to the type of used natural sources:
- receiving water from surface sources (river, lake, etc.);
- receiving water from underground sources (springs, artesian/pressure spring, etc.);
- mixed type.
According to the type of water use:
- direct-flow (once-through) water supply systems (with non-recoverable water use);
- recycling water supply systems;
- water reuse systems.
