Water intake from underground sources
The composition of the water intake and their General arrangement
Off-site water supply systems from groundwater sources consist of:
rainwater (meter) facilities for water intake, water wells (aquifer);
pumping stations of the first lift of water-meter devices;
prefabricated culverts that collect water from meter devices and conveying this water to the water treatment system (if necessary to improve water quality) or feed it in tanks for subsequent transportation to consumers;
facilities for water treatment and advanced water treatment to the required quality;
pumping stations and main conduits for transporting water to the consumer;
structures automation to regulate pressure and flow of water before supply to consumers in the internal network.
This is a typical scheme of functioning of groundwater abstraction. Rainwater (or meter) devices are drilling wells for water. The scheme, as well as the presence and mutual arrangement of the individual components thereof, may vary somewhat depending on hydrogeological conditions in a particular locality (presence of aquifers, quality of water, capacity of water intake), distance of source of water supply from consumers and the number of the latter; and from other possible conditions.
Thus, when the siphon method of selection of water pump stantsii and II recovery are usually combined in one building. If the water quality does not require its improvement of water supply schemes exclude appropriate facilities. If the water needs more serious treatment, such as in the deferrization and the fluorination, the complex of buildings included in the scheme of water supply expands. At a considerable distance from water users of a water supply source and a relatively large height difference in the terrain after the pump station of II lifting, constructing pumping stations III, IV lift, etc.
In groundwater used the following types of rainwater (meter) facilities: oil wells; dug wells; horizontal water intakes, combined water intakes; intakes of radiation; captai sources (springs). The choice of the type and schema of the intake depend on the hydrogeological conditions, the intended performance of the water intake and the technical and economic considerations.
Drilling wells is the most common type of water intakes. They are used for the extraction of groundwater in a variety of hydrogeological conditions. The depth of the well is determined by depth and operational capacity of the aquifer and can vary from 5-10 to 1000 m and more.
Wells are satisfied, as a rule, at first from the surface unconfined aquifer composed of unconsolidated rocks (Sands, gravels) are relatively limited thickness (10 m). Sometimes wells and constructing in confined aquifers at the depth of them up to 30-40 m from the surface. However, the device of mine wells of such depth it is useful only in low voodoobilly of the reservoir and the impossibility of creating a water intake from the wells.
Horizontal water intakes — drains, galleries, gallery — arrange also in non-pressure reservoirs when their capacity up to 8 m, predominantly near surface watercourses and water bodies.
Combined intakes consist of horizontal drains (galleries, galleries) of a system of vertical wells connected with them. This type of construction of water intakes appropriate in the presence along with the main captured unconfined aquifer deeper artesian waters.
Radial intakes are impervious dug wells branching off from them with horizontal beams-wells (drains). Dug wells serve in this case, structures to collect water from horizontal wells. Radial intakes are satisfied if the depth of the roof aquifers of 15-20 meters, and power them does not exceed 20 meters.
Pebble in water-bearing rocks in 70 mm and the presence of inclusions of boulders over 10%, and silty fine-grained rocks and when possible intensive colmatation filter zones of horizontal wells-rays to build a radial intakes is not recommended.
Captage sources (springs) arranged in the form of catchment chambers or standpipes shallow wells and used to capture groundwater in the presence of concentrated their exits to the surface.