Decentralized water supply involves the withdrawal of water from underground sources for drinking and household needs without its delivery to the destination. Most users have a strong confidence in the safety of underground moisture storage, which has passed through the filtering layers of soil. But this incorrect opinion is refuted by the performance of fluid samples taken in various areas.
Determination of decentralized water supply and its difference from centralized
In rural areas where it is not possible to organize water supply for the population along highways, sampling points from underground natural reservoirs or aquifers are arranged using various devices that are personally or publicly owned. To raise groundwater, mine and capturing wells are being built, artesian wells are being drilled.
In cities and towns covered by main water pipelines, water is supplied from the source to the place of use through a piping system. The complex scheme includes:
- underground storages or open reservoirs where water is drawn;
- water treatment complexes, consisting of structures for filtering and receiving liquids with the required level of quality;
- tanks for clean water;
- distribution stations;
- backbone networks;
- water pipes.
The list of elements indicates a fundamental difference between the ways of supplying the population with water resources. Water supply in rural areas does not have water purification complexes, distribution stations and main networks. The role of reservoirs of pure water is taken by domestic vessels into which the delivered water overflows.
Current requirements
The state attaches great importance to the protection of natural sources. November 25, 2002, Decree No. 40 was issued on the approval of SanPiN, which impose certain requirements on the composition and quality of water extracted from wells and wells: smell, turbidity, rigidity, mineral content and taste. For field water supply, criteria are approved that should be followed when choosing water intake sites, as well as the rules for their arrangement.
An underground source survey includes data on water quality and the sanitary condition of the surrounding area. Information is collected on the possible causes that can cause infection by germs or toxic substances.
Selecting a location for the source
A guarantee of water quality is the correct selection of places for the construction of the well. This protects it from the invasion of dangerous microorganisms and toxic compounds, does not allow turning the source into a focus of infection.
Corresponding data on places of catchment are contained on hydrogeological maps, which are compiled on the basis of sanitary and geological exploration studies in the area.
Near the chosen point, the presence of burials and cattle cemeteries, places of storage of toxic chemicals, landfills, cesspools and other objects polluting the nature is not allowed. To prevent groundwater from entering a well or well, they are arranged no closer than 50 m higher on the slope from the channel of the rain stream.
It is unacceptable to organize a water intake point in a swampy or periodically flooded area, as well as in places where landslides are possible. An artificial source is permitted at least 30 m from busy highways.
Device and equipment for water intake facilities
There are several types of structures for water intake from underground sources:
- mine wells;
- artesian wells;
- springs.
Aquifers can be located at different depths. If they are not far from the surface, dig a well in which fluid is collected that has passed through a natural filter from sedimentary rocks. The shaft may have a round or square section.
The device includes:
- the upper element of the barrel structure, called the head (superstructure above the source);
- shaft, side surface of the shaft;
- the cavity in which moisture is collected, i.e. water intake.
The head protects animals and people from dirt and falling, so the height of the structure above the surface should be 0.8 m. The well is covered with a lid or a canopy is erected over it. Sometimes a special structure is adapted for this.
A “castle” of compacted clay, the depth / width of which is 2/1, as well as a blind area around the perimeter of two meters around the device, made with a slope from it, are designed to protect the well from landslides and destruction, runoff or seepage of surface water. For safety, the wells are fenced, next to arrange a pedestal for buckets.
Wells are tubular wells that can have a depth of more than 100 m. Their arrangement is carried out using pipes for casing. To raise the water, use a pump with a filter to prevent clogging. The superstructure on the surface is carried out similarly to conventional wells, with a blind area and a bench. The tip rises to a height of 1 m, the well is closed by a casing, water is supplied through a drain pipe, onto which a hook for buckets is welded.
Kaptazhny wells are arranged for the abstraction of spring water. They are of two types:
- descending - water flows from the wall of the well;
- ascending - there is a cavity for collecting fluid.
They also have a fence, are equipped with a water intake, overflow system and sunroof. Water intake is carried out from a pipe with a diameter of at least 10 cm. Captages are placed in the pavilions and equipped with a pipe to remove stagnant odors.
Maintenance and operation of water intake facilities
Careful attitude to the source requires compliance with the rules for its operation:
- it is unacceptable to wash cars and wash clothes at a distance closer than 20 m from the appartment;
- if the well is not equipped with a pump, they collect water in a public bucket, from where it is poured into the brought containers; for this purpose you cannot use household utensils and scoop up water from a public bucket with the help of a brought bucket.
In winter, the well needs to be insulated with environmentally friendly materials that are allowed by the Ministry of Health of the Russian Federation for household and drinking sources. Sawdust and shavings from woodworking shops are suitable for this purpose. In cold weather, sediment needs to be heated.
Once a year, or as needed, the wells are cleaned by scooping up the remaining liquid, and they are repaired, simultaneously carrying out disinfection measures. If a decision has been made to dismantle, the well is filled up, ramming the soil tightly.
Water quality control
To ensure safe water use, sanitary and epidemiological surveys of wells and the surrounding area are periodically performed. This rule applies to functioning and new, commissioned facilities.
If sanitary indicators deviate from the norm, re-sampling is done for control. If deterioration is proven, take measures to identify and eliminate the causes of infection. This work is carried out by specialists who clean and disinfect the well. If the source of chemical poisoning cannot be eliminated, the intake device is eliminated.
