Well Water Filters

If water is supplied to the house from a well, it requires treatment. Sand, clay, iron, manganese, nitrates, bacteria, hydrogen sulfide – this is not a complete list of what it may contain. Depending on the degree of contamination, equipment is selected – sedimentation tanks, aerators, filters. In order for the filters for water purification from the well to be selected correctly, its chemical analysis is necessary, and preferably expanded: it will be possible to more accurately select equipment for purification.

Cleaning steps

Purification of water from a well takes place in several stages:

• Pre-cleansing. At this stage, coarse impurities are removed from the water raised from the well – sand, dissolved clay, and other mechanical particles. This can be done in two ways: coarse filters or sedimentation tanks. It is very undesirable to omit this stage: large particles quickly clog fine filters and can even break them.
• Removal of iron, magnesium and some other chemical impurities and gases.
• Softening is the removal of salts by ion exchange, while the salts precipitate and their residues are removed in the next stage.
• Fine cleaning and disinfection. At this stage, biological purification from microorganisms and bacteria occurs. And fine filters filter out small particles.
• Drinking preparation. At this stage, they usually put filters that work on the principle of reverse osmosis. Only that part of the liquid that goes to cooking or drinking is driven through them.
  

In each case, the number of purification steps is determined based on the analysis of water from the well. If the content of any substances exceeds the norm, methods are selected to reduce their concentration and equipment for this.

You can read more about irrigation systems here.

How to clean sand from well water

The removal of sand or particles of clay, silt, and other large particles occurs on a filter lowered into the well. This is done using simple mechanical filters – lamellar or sandy, and this stage is called the coarse cleaning stage.

If you weigh a lot, one filter is not enough: it will quickly become clogged. It is more practical to put a system with cells of different sizes. For example, water from a well enters a filter that captures particles up to 100 microns in size, then a filter with a purification rate of up to 20 microns is installed. They will remove almost all mechanical impurities.

Filter types

Coarse filters are: mesh, cassette (cartridge) or backfill. Mesh are most often placed in the well itself. They are a hollow pipe with a slightly smaller diameter than the wellbore. Holes are drilled in the walls of the pipe or slots are made (the shape of the holes depends on the soil), a wire is wound on top, and a mesh is wound along it. The mesh cell is selected depending on the type of soil in the aquifer: it must retain the bulk of the contaminants and at the same time not be clogged. At this stage, the largest impurities are retained, which, moreover, can damage the pump. But some solid particles still rise to the surface. They are removed during further purification.

Sometimes it is not possible to put a filter in the well. Then all cleaning is transferred to the surface. In this case, cassette or backfill filters are used to purify water from a well. There is a replaceable cartridge in cassettes – a system of membranes, crushed charcoal, etc. on which sand and other large contaminants settle.

Cartridges get clogged from time to time and need to be replaced. The frequency depends on the degree of water pollution and the intensity of its use. Sometimes one cartridge becomes clogged quickly. In this case, it makes sense to install two filters with different degrees of purification. For example, the first one delays particles up to 100 microns, and the one behind it is already up to 20 microns. So the water will be clean and the cartridges will have to be changed less often.

In bulk filters, loose filter material is poured into the container – sand, crushed shells, special filtrates (for example, BIRM (BIRM)). The simplest mechanical filter is a sand barrel with a flushing function. One caveat: in the presence of a large amount of dissolved iron, it is still preferable to fill in a special filtrate, it is also a catalyst that oxidizes the dissolved iron and manganese, causing them to precipitate.

Depending on the particle size of the backfill of such a filter, quite small particles can be retained. Sometimes they put two such filters in a row, only with different filling – first, water enters the one where the filtrate is large, then with a finer filling. Bulk filters for purifying water from a well are good because they require replacement of the backfill approximately every three years. And in this they differ from lamellar ones, the filter of which needs to be changed much more often: sometimes once a month, sometimes once every three to six.

But in order for cleaning with a back-up filter to be effective, they need periodic washing of the filtrate. This usually happens by shutting off some faucets and opening others. In this case, the water goes in the other direction, washing away the main amount of accumulated precipitation.

An example of assembling two sequential filters for water purification from coarse impurities, see the video.

How to make a bailer to clean the well can be found here. 

How to clean water from a well from iron

The most common problem with water lifted from wells is excessive iron content. If we talk about sanitary standards, then the permissible level of iron in water is 0,3 mg / l. If the concentration rises, a specific taste appears. With an iron content of more than 1 mg / l, the color already changes – after a short settling, a characteristic reddish – rusty – shade appears.

There is no reliable data on the occurrence of pathology or the development of any diseases when drinking water with an increased amount of iron, but drinks and food are far from the most attractive appearance and taste. But such water can help with a low content of hemoglobin in the blood, if you drink it long enough. Nevertheless, water is more often purified from iron, and, at least, to sanitary standards. The reason is that iron is deposited on household appliances, which often causes it to fail. There are several types of equipment for removing iron from water.

Reverse osmosis

This is perhaps the most effective way: almost all particles are removed. This water purification equipment has special membranes that allow only H2O molecules to pass through. All the rest settle on the filter. A special cleaning system allows you to automatically remove accumulated contaminants that are discharged into the sewer or drain pit.

Reverse osmosis removes not only iron, but also all other substances dissolved in water. The problem is insoluble particles, including sand and ferric iron (rust): they clog the filters. If you have a large amount of these impurities, coarse filters (described above) will be needed before the reverse osmosis equipment. Another nuance: this equipment is installed on a water pipe and works under a certain pressure.

Still, the main disadvantage of such a system is its high cost, and the filters are also not cheap, and they need to be changed at about the same frequency as in cartridge installations (once every one to three months). Therefore, most often this equipment is installed for the preparation of drinking water – they are installed under the sink, a separate tap is removed and used only for drinking or cooking. To purify the rest of the water – for technical needs – use other methods and methods.

Well water filters with ion exchange resins

According to the device, they are very similar to cartridge ones, but they contain special filters with resins that replace iron with sodium. At the same time, water softening occurs: magnesium and potassium ions are also bound. This equipment has several types of devices. Cartridge filters are suitable for small volumes, for large volumes they are no longer enough and filter columns are installed, which can provide clean water at a significant flow rate. That is why when selecting filters and equipment for cleaning water from a well, an average and peak flow rate is also required: in order to choose the right capacity.

Removal of iron from water by aeration

Well water filters are effective, but far from cheap equipment. You can solve the problem easier: with the help of aeration. The fact is that iron is present in water in two forms: the dissolved divalent form and the trivalent form that precipitates. The principle of aeration is based on the addition of oxygen to water, which oxidizes ferrous iron dissolved in water to trivalent iron, which precipitates in the form of a rusty precipitate. In addition to rust, this method neutralizes manganese, hydrogen sulfide (gives the smell of rotten eggs), ammonia.

Pressure aeration systems

According to the device, aerators can be divided into non-pressure and working under pressure. The pressure aerator consists of an aeration column and a compressor that pumps air. At the top of the column there is an automatic bleed valve that removes excess air. Water can get into it, so it is connected to the sewer system.

Water is taken from the lower third of the aeration column, but not too low, as insoluble sediment accumulates at the bottom – the result of purification. The system turns on only when there is a flow of water. To do this, there is a flow sensor at the outlet. As soon as the tap is opened, the compressor turns on, closed, it turns off.

The pressure aeration system is also not the cheapest pleasure. But it is necessary if the content of iron or other dissolved substances is exceeded by 30 or more times. Otherwise, you won’t get rid of so many contaminants: the filters will become clogged very quickly.

Non-pressure aeration water treatment systems

The second type of aeration system is non-pressure. It has a large container in which water settles. The volume of the tank is from 600 liters, but in general it depends on the water consumption: no more than 50-60% of the available volume should be consumed so that the sediment remains at the bottom.

Water is supplied to the tank directly from the well. The water level can be controlled by sensors – lower and upper levels or, as in the photo, a float switch of a borehole pump. To protect the system from overfilling, a water discharge pipe is made just above the critical level. It can go into the drainage or sewer system. It is important that there are some visual indicators that there is too much water in the tank.

Such a system works as follows: Water is drawn into the tank to the required level, after which the pump is turned off. To purify the water, a compressor (possibly powerful for aquariums) is turned on, which supplies air to the tank. It is distributed through the divider, which is located at about half the depth.

To ensure constant pressure in the system, water from the tank can be pumped out using a pumping station. Water is taken from the lower third, but not from the very bottom (through Tap 1): the purest water accumulates here. It enters the pumping station through Crane 3 and from there through the tee and Crane 5 goes into the system.

The scheme above also provides for a cleaning system. In this case, Valve 2 and Valve 5 are closed, Valve 2 and Valve 4 are opened. Sediments from the bottom in this position of the locking elements are drained into the sewer or drainage system. After the precipitation has been removed, you need to drain some more clean water in order to rinse all the pipes well. Only when clean water goes into the sewer, all taps can be returned to their original position.

Read more about drip irrigation systems here. 

Do-it-yourself water purification systems from a well

One of the options for home-made water purification from a well using the aeration method is shown in the photo below. Two stages of aeration are used here for a more complete water purification and removal of all impurities. The need for the second stage is determined based on the results of cleaning the first stage: the quality is far from always satisfactory. Re-aeration can help with this, but this is far from the only way: you can put one of the filters. He will do a good job, and will rarely clog.

In this embodiment, water from the well is supplied through shower heads. Thus, primary oxygen enrichment occurs. There is also a submersible atomizer from an aquarium compressor. The water level is controlled by a float switch (used to control the water in the pool). At the bottom of the tank there is a tap for draining settled substances.

From the first tank, water is taken in the same way as in the previous version, from the lower third. the system is organized in the same way. From there, water can be supplied to the final cleaning and disinfection filter, and then it is diluted around the house.

See the video for another example of a home-made water purification system from a well.

Homemade water purification tips

If we talk about home-made systems, water purification from a well, then different approaches and methods are often used. Here are some quotes:

I remove iron cheaply and simply. I have a 120 liter tank. I pour 7-10 grams of lime into it, then I blow it with a compressor from the aquarium for 4-5 hours and let it settle for 3 hours. Then I supply water to a filter with a 2 micron cartridge, and from there into the system. This method was made in the country. I change the filter once a month. A friend at home made the system larger – by 500 liters. There are two compressors running 12 hours. If you increase their power, the time can be reduced.

The second option is no less interesting:

I had a lot of sand and silt coming out of the well: my consumption is high and it “pulls” a lot of all sorts of rubbish. I solved the problem by installing a filter. I only gutted my own cassette (after the filter became unusable), and poured crushed shells into it. Some pour marble chips. Works fine too. Only the fraction is needed not small, otherwise it will be quickly clogged. And then I have a tank with a purge (aeration), and after it there is a filter that removes what the first two could not. The last filter I have is a barrel filled with BIRM. It has a faucet for washing. So once every couple of weeks I wash the backfill, and it needs to be changed after three years.