An autonomous source of water supply in a suburban area is a good alternative to centralized communication. More often, craftsmen prefer to equip a well or a well. With proper installation and operation of sources, their flow rate remains constant. But there are frequent cases when a hydraulic structure in the lower part is overgrown with sludge, which leads to a decrease in its productivity. If the well is silted up, it needs to be cleaned. There are several washing methods. It is important to choose your own in accordance with available opportunities and finances.
Signs of siltation
The problem of fouling of the sludge source affects wells on sand more. This is a feature of their design. Grains of sand, overcoming even the smallest filter mesh, sooner or later densely fill the lower part of the casing. This prevents the free flow of water into the mine. The sure signs of siltation of the source are a decrease in flow rate (especially after winter downtime of the hydraulic structure) and an admixture of a large amount of turbidity, sand in the water.
Silt fouling is also characteristic of an artesian well. But such phenomena are more rare.
The root causes of the problem
Sanding, and then siltation of the lower part of the hydraulic structure occurs with such provoking factors:
- Source exploitation in periods. If the well is used only in seasons, the alternation of the flow rate from the bottom by itself provokes the sedimentation of silt on the filters. With a strong pumping of liquid, its volumes seem to randomly wash the grid. As soon as the flow stops, all grains of sand slowly settle to the bottom and form a dense silty crust.
- Incorrect installation of the bottom of the casing. If it is located outside the aquifer zone or in the part where water arrives more slowly, sooner or later problems will arise with filter overgrowing, since the dynamics of fluid movement is extremely low.
- Incorrect pump location. If it does not reach the bottom (normally 1 m from its lowest point) and also has an upper fence, silting cannot be avoided.
- The use of rotary pumping equipment, which cannot be lowered below 10 m. In such situations, all the agitated particles of clay or sand settle to the bottom.
An important factor is the complete tightness of the casing. If the column is damaged in the artesian well, soil, sand and clay can ooze into it along with the underground waters of the upper horizons.
Methods for cleaning wells from sludge
Cleaning the well from sludge can be done on its own or invite specialists for this. It all depends on the depth of the source and the scale of the problem.
Cleaning using a bailer
This is the simplest home-made way to clean shallow hydraulic structures (up to 15 meters). Deeper alone can no longer cope. To complete the work, you will need:
- strong winch (preferably electric);
- a piece of steel pipe with teeth at one end and special flaps (choke);
- the pump is powerful, as efficient as possible (it can be drainage or fecal) for pumping sludge-polluted water.
The work is carried out in the following sequence:
- Pump water from the source to the maximum.
- The winch is installed strictly above the well.
- Attach the bailer to it with the teeth down. Its diameter should be less than the cross section of the casing.
- With force (with a free fall from a height of about 1-1.5 m) lower the steel flask to the bottom of the source.When impacted on silt, the shutter doors open and capture some of the contaminants with water. When raising the flask, the blades will close and will not allow dirt to fall back into the shaft of the shaft.
Thus, they act until the volumes of sludge that are raised do not decrease significantly.
When operating the bailer, a pump is switched on in parallel to pump out the de-agglomerated water. Work is performed continuously until the cleanest fluid flows from the well.
Using airlift
This method involves the use of a special compressor. To begin with, a smaller section pipe is installed in the casing. Compressed air is already fed into it, which will loosen the silt deposits and thus clean the source bottom. Water mixed with air and sludge is converted into foam, which, when the pressure is changed below, is pushed up.
Doing this work on your own is relatively difficult. Here you need to have certain skills and control the water level in the inner pipe.
When pumping out the silted volume, a tank with a sieve or a mechanical filter can be installed next to the hydraulic structure. Merging a resource here, it is cleaned of impurities and then used for technical purposes or for irrigation.
Mechanized cleaning method
Two types of pump will be required - one for supplying clean fluid under high pressure to the bottom of the well, the other a drainage pump for pumping silted water from below. Turn on both units at the same time. Moreover, the drainage pump must be located as close as possible to the bottom of the source. The supply of clean water under pressure is done from about a height of 50 cm from the bottom of the column.
Fire truck help
This method is suitable for those who are confident in the strength of the casing with a filter and have enough money to rent equipment. The principle of cleaning the source is to supply a stream of water into the well through a fire hose and the same reverse pumping of liquid with sludge. It takes half an hour to flush with special equipment. But if the elements of the well are flimsy, there is a risk of damaging them. It is convenient to clean the hydraulic structure in this way.
Comprehensive source cleaning
Several methods are used simultaneously to clean the source. First of all, water and all large debris are removed from the mine as much as possible. Then, under high pressure, water is fed into the column, eroding the silted bottom. At the same time, dirt is pumped out using a powerful pump. The next step is to rinse the filter and pipe with special reagents or acids.
It is important to consider that improperly proportioned chemicals can be harmful. Mostly professional drillers work with acids and reagents.
In conclusion, perform a water hammer using special equipment. It removes residues of sludge, used chemicals.
Prevention of siltation
To prevent the formation of a sand-organic crust from the bottom in the well, a number of preventive measures should be taken:
- Closely follow established drilling technology and ensure complete casing tightness.
- Thoroughly pump the well after installation until absolutely clean water appears.
- Mount the head and protect the shaft of the mine from atmospheric precipitation and small debris.
- Properly mount the submersible pump in compliance with the optimum depth (a meter from the bottom), which does not allow sand to silt the filter screen.
- Use only a vortex or centrifugal pump, but not a vibration pump.
- Operate the source constantly to provide dynamic fluid movement in it. If living on the site is seasonal, it is better to pump out 100 liters of water each month from the well.
Subject to such recommendations, the hydraulic structure will not cause problems to the owner, silt.
