- Shallow well
- Deep well
- Industrial wells
- Materials and equipment
- Water purification systems
- Selection of pumping equipment
The organization of water supply to a cottage or summer house from underground sources requires building a complete technological chain – from drilling a well to water treatment systems. The initial stage of this process is to determine the water content of your site.
There are two main types of underground water locations:
– wells 10-15 m,
– Quaternary 15-30 m,
– Cretaceous (supra-Jurassic) 30-50 m.
Limestone depths – from 30 to 230 m – are called artesian. In the Moscow region, the first artesian horizons lie unevenly:
– south direction 30-60 m,
– north direction 90-180 m,
– west-east direction 60-90 m.
Large water flow rates provide wells with a depth of 20 to 200 meters, depending on the occurrence of groundwater. Surface water in ordinary wells is not able to cope with the task of providing water consumption up to 500 liters per hour. They are reliable for water consumption up to 100 liters per hour, but the sanitary quality of well water is naturally very low. Waste from industrial plants reaches even the deepest soil levels. Nitrates and nitrites, heavy metals, bacterial pollution – the source of many troubles for human health enter the body along with water.
In terms of total costs, the well is much more expensive than the well, but the risk of getting poor-quality water with the correct water treatment technology is minimal.
“Sandy” wells provide water for a country house with two points of water intake – a tap in the kitchen and a tap for irrigation. To provide a cottage with a European level of comfort, having several bathrooms, a washing machine, a dishwasher, a swimming pool, an artesian well is needed. The service life of a “sandy” well is determined by the properties of structural materials and the professional level of the installers and averages from 5 to 15 years. Water yield depends on the seasonal recharge of the aquifer – during dry periods the well can “dry up”.
The state considers artesian waters to be a deposit and, accordingly, regulates their consumption by licensing such wells. A technologically competently constructed artesian well operates smoothly for up to 50 years.
To ensure the cleanliness of the opening and isolation of the used aquifer, a special well design is required. It should have casing to prevent wall collapse when passing through loose sediments and to isolate non-target aquifers. New special substances for isolation have appeared – compactonites, which are poured into the isolated section of the well in the form of tablets. Then, under the action of water, they turn into an impermeable plastic mass, which forms a reliable plug at the entrance to the target horizon and does not give contamination. Internal pipes and materials contribute to the purity of the consumed water. Recently, durable PVC or HDPE plastics have been used. Polyvinyl chloride pipes are lightweight and strong, durable and not subject to corrosion. Environmental and hygienic cleanliness of PVC pipes has been proven by appropriate tests and requirements for food grade plastics.
Special drilling rigs carry out the process of drilling a well. Thick-walled steel pipes are inserted into the finished well. A deep pump 3-4 inches in diameter is submerged through them. The pressure pipeline from the pump goes to the surface and is led into the house. If the upper part of the well with the inlet pipe is deepened 1.5–2 meters into the ground, then water freezing in winter is excluded. To exclude the ingress of groundwater into the well, a caisson is installed above the wellhead – a kind of well in the form of an underground metal chamber, which serves for the convenience of pump operation and maintenance of the water supply system.
Further, water enters a membrane tank with a capacity of 100 to 500 liters, depending on the performance of the pumping device, located on the first floor of the house (basement) through a coarse filter. This tank is required to optimize the operation of the submersible pump by storing a supply of pressurized water. Water enters the open tap not from the pump, but under pressure from this tank. The service life of the pump increases, since it operates in a mode that ensures automatic activation only at high water flows or when the pressure in the system drops to a lower set limit. At the same time, he pumps water into the tank until the pressure in it reaches the maximum value.
Drilling the well will take three to seven days, depending on its depth and complexity. Only a professional driller can determine where there is water underground. Consultation with experts will help you choose the best option that will ensure the operation of the water supply system for a long, long time.
Subsequent stages of work with the well: long-term pumping of water to assess its operational capabilities, full chemical analysis to conclude that the water meets the requirements of GOST. The owner must obtain a passport for the water-lifting unit indicating its main characteristics. This document is required both for local supervision authorities and for the operation of repair and restoration work..
Individual wells can be divided into two types (conventionally): shallow and deep.
Shallow wells are drilled, as a rule, on aquifers of sandy horizons at a depth of 15–35 meters. Drilling is performed with augers, which in appearance represent the working part of the corkscrew.
Typical shallow well layout:
Seamless hot-rolled pipes (Steel 20) with a diameter of 127–159 mm are used as a casing string, the connection type is threaded. The filter is a perforated steel pipe equipped with a galloon mesh made of stainless steel or brass No. 52, 56, 68. The well is operated using vibration pumps (“Kid”, “Aquarius”, etc.). Its productivity is 0.3–0.5 m3 / hour. Due to their low production capacity, wells of this type are not very suitable for water supply and are mainly used for watering garden plots. However, sometimes they can be used to supply water to small country houses, while a filler tank is used. As a rule, water from such wells belongs to the category of technical water and is of little use for domestic needs and drinking. In addition, such water is characterized by high concentrations of iron, sometimes – manganese..
For autonomous water supply, the best option is an artesian well with a depth of more than 30 meters (limestone aquifers). Drilling in this case is performed with flushing with more powerful rotary-type installations and subsequent cementation of the annular space. Environmentally friendly drilling fluids and additives to them, which have a quality certificate and exclude the possibility of contamination of exposed aquifers, are used as flushing fluids. For cementation of the annulus, high-quality cement mixtures are used, which provide reliable insulation and exclude the possibility of contamination from the surface of the exposed aquifers.
The output from a deep well can reach 5 m3 / hour. Equipping it with the appropriate water supply equipment, you can create a system of comfortable water consumption.
Pipes (Steel 20) with a diameter of 133 mm serve as a casing string, the so-called conductor. Directly in the interval of the aquifer, it is possible to install a perforated column.
There are several variations of well arrangement. For example, JSC “Gidroinzhstroy”, according to its technology, uses polyvinyl chloride pipes (PNDTU 273) with a wall thickness of 12 mm and a diameter of 135 mm as a production casing, which meet the requirements for food grade plastics. In addition, the taste of water, unlike metal, is not affected.
Typical deep well setup:
The total cost of work at the facility should include travel to the drilling site, work performance, cost of materials, pumping out and a guarantee for a drilled well up to several years.
The contract for the production of work on drilling production industrial wells for centralized water supply is concluded only if the customer has a license for the right to use subsoil (water use), which is issued by the territorial management body of the subsoil fund and the constituent entity of the Federation on the territory of which drilling will be carried out … Drilling work for centralized water supply is carried out strictly according to projects with a permit for drilling wells.
Depending on the location and geological conditions, industrial production wells are drilled with powerful drilling rigs such as the Podolsko-Myachkovsky industrial aquifer or the Oksko-Protvinsky .
Materials and equipment
When installing borehole water supply, it is recommended to use environmentally friendly certified materials produced by leading domestic and Western companies, such as: GRUNDFOS, WILLO (Germany), PEDROLLO (Italy), etc..
The provision of automatic control of a submersible pump, as mentioned above, is carried out using a diaphragm tank, but at the same time a pressure switch and a control system are used, which, interacting, are capable of and maintain a constant pressure in the system.
Water purification systems
In modern water supply technology, a number of devices are implemented that allow you to solve almost any problem with water. All of these complex systems can be called filters. They can be classified according to their application, that is, depending on the specific function..
The following properties of water need to be addressed:
– the presence of undissolved mechanical impurities;
– the need to adjust the pH level;
– iron and manganese dissolved in water;
– presence of taste, smell, color;
– bacteriological contamination.
Required filters and equipment:
– sediment filter;
– iron removal filter;
– salt dissolver tank;
– carbon filter;
– ultraviolet sterilizer;
– drinking water treatment system.
Designed to remove mechanical particles, sand, suspensions, rust, and colloidal substances from water. To remove relatively large particles (over 20-50 microns), mesh or disc systems are used. The disadvantage is the relatively low dirt holding capacity. If the water is heavily contaminated or if the capacity is high, they require frequent flushing. In these cases, it is advisable to use automated charging systems. Mainly dehydrated aluminosilicate is used as a filtering medium, providing filtration of particles from 20 microns. For finer cleaning, use a filling made of special ceramics.
PH corrector systems:
The need to adjust the pH level arises if it is necessary to combat corrosion, since water with both low (less than 6) and high (above 8) pH has an increased corrosive effect. On the other hand, to ensure the optimal operation of water purification systems, since for the normal operation of some types of filter media, a certain pH level is required.
To change the pH level, fillings are used based on natural calcites, which, gradually dissolving, increase the pH. It also uses a metered addition to the water of chemicals that lower the pH level..
Iron removal systems:
Systems of this class are intended mainly for removing iron and manganese from water, which are present there in a dissolved state. Various natural substances are used as a filtering medium, including manganese dioxide (Birm, Filox, Greensand, etc.). Manganese dioxide serves as a catalyst for the oxidation reaction, in which iron and (or) manganese dissolved in water transform into an insoluble form and precipitate, which is retained in the layer of the filtering medium and is subsequently washed out into the drainage during backwashing. In the process of oxidizing iron and manganese, some systems also effectively remove hydrogen sulfide dissolved in water. Some of the filter media require regeneration with potassium permanganate. At high concentrations of iron and (or) manganese, special techniques are used to promote their more intense oxidation. The most promising direction in this area is ozonation.
An extensive class of devices designed to reduce water hardness. Thanks to the use of special backfills, systems of this type can have a complex effect and can also remove certain amounts of iron, manganese, nitrates, nitrites, sulfates, heavy metal salts, organic compounds from water.
Activated carbon has long been used in water purification to improve the organoleptic properties of water (to eliminate foreign taste, odor, color). Due to its high adsorption capacity, activated carbon effectively absorbs residual chlorine, dissolved gases, and organic compounds. However, since the accumulated organic matter is difficult to remove from the coal during backwashing, a salvo discharge of contaminants into the outlet line is possible. To prevent this phenomenon, the activated carbon backfill requires periodic replacement. Currently, to increase the service life, activated carbon from coconut shells is used, the adsorption capacity of which is 4 times higher than that of coal obtained by traditional methods (for example, from birch wood). To combat biological overgrowth, special coals with bacteriostatic additives are also used, as well as backwash systems..
The most common method of dealing with bacteriological pollution (the presence of microbes and bacteria in the water) is irradiation of water with ultraviolet light. The radiation parameters are selected in such a way that they guarantee almost complete sterilization of water. As sterilizers of this type, special ultraviolet lamps are widely used, mounted in a rigid case, inside which water flows, being exposed to ultraviolet radiation.
Drinking water treatment systems:
The most advanced systems for the preparation of drinking water are currently reverse osmosis systems. Water obtained with the help of such installations has excellent taste and its properties are close to glacial melt water. The key component of such a system is a semi-permeable membrane, the quality and material of which determines the degree of water purification, reaching 98–99%. To ensure normal operation, the system is equipped with preliminary cartridge filters, a pump, etc. depending on the parameters of the source water. Such systems are installed, as a rule, in the kitchen and are used only to obtain water used for food purposes. Commercial drinking water treatment systems can also be used.
Selection of pumping equipment
One of the key mechanisms of borehole water supply is a pump. Deep well pumps are capable of lifting water from a depth of up to 300 m, while creating the required water pressure in the house with a flow rate of up to 15 m3 / hour. In this case, at sufficiently high flow rates, accumulators with a capacity of 300 liters or more are used. The calculation and selection of equipment at the design stage of an autonomous water supply system is based on the initial data on the source of water supply. In the case of using a well, the main requirement for pumping equipment is reliability. Therefore, pumps of leading Western companies have several degrees of protection: from “drying out”, power outages, small stones entering the water intake, etc..
In each case, the optimal pump option is selected taking into account such parameters as the inner diameter of the well casing, the depth of the water table, the required flow rate and water pressure.