Safe distance from power lines to a residential building. Acceptable standards of SanPiN

It is known that dangerous electromagnetic waves emanate from high-voltage lines (OHVs). The approved provisions of SNiP regulate the minimum safe interval from power lines (power lines) to residential buildings, which depends on the voltage in the network. Based on these intervals, the sanitary zones of power lines under the overhead lines and the “encumbrance zone” are determined, which is an area at a dangerous distance from waves harmful to human health. The construction of any housing on the territory of the sanitary zone is strictly prohibited.

Minimum allowable interval

Charged particles, while moving through wires, form an electromagnetic field, that is, radiation, which is divided into constant and alternating. Frequent changes in electric current from plus to minus and in the reverse order produce a change in the field value several times faster.

As is known, electromagnetic radiation has a detrimental effect on the human body. The World Health Organization, based on the results of numerous scientific experiments, has approved permissible radiation standards. In many states, including our country, regulations have been created and legislatively approved that impose a ban on any construction in areas close to power lines.

People who were exposed to a powerful electromagnetic field for a long time subsequently suffered from serious illnesses, chronic fatigue, and their life expectancy decreased.

The distance at which power lines are installed to the fence

In the matter of building a house and equipping its territory, many issues are important. This includes the distance from the power line to the fence, which everyone who has started building a fence for their private plot should know about. The safety of those who come to the territory on vacation or permanently reside on the territory depends on the correct calculation of the distance from power lines to the fence of a private house.

Diagram with dimensions of the location of the fence from the power line

Important points

A person uses electricity all the time, be it at home, in the country or in the office. But few people delve into the fact that power lines not only supply a useful resource, but can also be harmful due to magnetic fields, and in case of failures they become unsafe for humans. It is imperative to adhere to the established rules, which indicate the required distance from the support to the fence of a residential private house for the following reasons:

1. To preserve the health of building occupants.
2. In order not to suffer from the effects of airborne electromagnetic fields that have a detrimental effect on the human brain.
3. In the security zone of power lines, where the voltage level is especially dangerous for humans, the issue of locating residential buildings is especially acute. If the level of danger is off the charts, the area is fenced off with an industrial fence and a ban on construction in this area is put in place.

Power line protection zone diagram

Therefore, SNiP establishes distances from power lines to the fence of a house not just so that people do not receive fines for violations, but for the safety of the population of cities and villages.

The sanitary standards related to power lines clearly and in detail describe at what distance from power lines fences can be installed. This distance depends on the voltage level in the wires. In places of special tension, which are specially equipped, there are sanitary zones, near which it is prohibited to place fences and build residential buildings.

Safe distance from power lines

A requirement is established for the distance from the fence at the dacha to the place where the power line support is located, based on the voltage class.

Some owners of private plots turn to city or rural self-government bodies in order to obtain information about the voltage class in power lines located near their summer cottage.

Of course, not knowing how to determine the voltage level in the wires, it is better to do just that, so as not to unwittingly become a violator of SNiP requirements and endanger the residents of a private plot.

However, there is a method by which you can independently determine the voltage level in power poles.

Diagram of voltages in power lines of various types

If the voltage is very small, then it can be determined by counting the insulators.

How to increase your security level

Even having fully complied with all the norms and requirements regarding the distance of the fence from the poles through which electricity passes, houses built near power lines are still at risk in unforeseen situations and must protect their private sectors. This can be done in the following ways:

• Select a roof with grounding for the construction of the house,
• Install reinforcing mesh inside the wall structure. This solution will help reduce the risk of penetration of harmful electromagnetic waves into the living space,
• To increase the level of safety for home residents, fruit trees should be planted at a horizontal distance of at least 2 meters from power lines.

Minimum permissible distances from trees to power lines

Recommendations

The requirements in SNiP are prescribed primarily for the safety of people, and not to fulfill the wishes of self-government bodies. Therefore, you should not neglect safety rules, especially when it comes to electrical voltage. It is worth paying maximum attention to calculations at what distance it is safe to install a fence from power lines. Only a properly installed fence will provide comfort and limit the residents of a private plot from troubles and danger.

Plots in the sanitary zone

Based on the provisions of SanPiN, a construction procedure and security zones under power lines were created. Children's institutions located at a dangerous distance from power lines must be closed immediately. In addition, it is strictly prohibited to construct residential buildings for various purposes closer to the safe interval range relative to power lines prescribed in SanPiN 2971-84.

The degree of danger of radiation can be clearly seen in the price indicators for land plots located in close proximity to power lines. Here the price of land is very low, and the price increases every 30 meters. But you should not be tempted by the low price, since first of all you need to take into account the importance of preserving the health of your family.

Safe distance to power lines

The standardized width of the sanitary zone does not meet the standards for maintaining a safe distance for the construction of residential buildings. Its value is 2 times less and its measurement is carried out not from the outermost wires of the power line, but is indicated by one value with the center of the overhead line axis.

Sanitary zones of overhead lines:

Permissible distances from buildings to power lines and their dependence on the voltage indicator:

• 20 kV – from 10 meters;
• 35 kV – from 15 meters;
• 110 kV – from 20 meters;
• 150 – 220 kV – from 25 meters;
• 300 – 750 kV – from 30 meters;
• 750 – 1150 kV – from 40 meters.

Is it dangerous to live near power lines: determining the voltage in power lines

• To understand how dangerous it is to live near power lines and what the safe distance from power lines , you need to carefully consider it. The minimum voltage is 0.4 kV; such lines are equipped with small transparent insulators and five wires.
• 10-kilovolt lines have much larger insulators (only 1-2 of them) and three wires.
• A 35-kilovolt power line has a wire attached to each of the three insulators.
• A 110-kilovolt line has 6 insulators on each wire.
• And the 150-kilovolt line is from 8 to 9. Next come the lines through which electricity is supplied to the substation, their voltage is 220 kV, and here the number of insulators reaches 40.
• In the most powerful lines (330-750 kV) the number of wires is from two to five, insulators - from 14 to 20.

Distance

Possible harm to human health

A voltage of 10 kV is officially recognized as safe for people, creating a background whose density is no more than 10 µT. For example, the Earth's magnetic field emits 30 μT, which every person experiences constantly.

Prohibitions in the power line zone:

Electric current flows through the overhead line with a frequency of 50 Hz, that is, the current changes direction 50 times per second. The magnetic field changes in the same order.

It is worth noting that if people are often exposed to a magnetic field with high levels, malfunctions may occur in the body. This also applies to household appliances that a person uses constantly, for example, a hair dryer, refrigerator, computer.

Standards for distances from supports:

Permissible intervals from power lines and the harm caused to human health are absolutely interconnected. In the European Union, housing construction is permitted within an interval of at least 20 meters from the sanitary protection zone.

European standards for housing construction:

It is worth noting that the site area for any construction is to some extent located closer to the power lines than the minimum distance from the residential building. This area is designated in the technical documentation as the encumbrance zone. In this territory it is not prohibited to erect a fence and plant a vegetable garden, but to build residential premises is not allowed.

Life under tension

In the USSR, the magnetic component of radiation from high-voltage power lines was not taken into account at all in safety standards. Both construction in the power line zone and residence were allowed. Magnetic radiation levels acceptable in Russia since 2007 are today tens of times higher than similar standards in Scandinavia and a number of other European countries.

The majority of experts interviewed by BN advise weighing and even taking some measurements before buying or building new housing near power lines.

A look into history

Oddly enough, humanity is much more aware of safe levels of radiation than critical levels of electromagnetic radiation. High-voltage power lines are precisely sources of an electromagnetic field of industrial frequency - 50 Hz. Their wires are a kind of antenna for radio waves of enormous length - 6 million meters, these waves are called “megameter”. For comparison: FM radio stations broadcast on waves several meters long, and GSM cellular networks use decimeter waves.

In the USSR, permissible standards took into account only the electrical component of the field, and the impact of the magnetic component on the human body was not assessed at all.

Buying housing on the secondary market: what are the risks? When purchasing an apartment, room or house on the secondary market, you need to thoroughly check the history >> There are no problems with the electrical intensity of the electric field. The maximum permissible voltage level inside residential premises is 0.5 kilovolts per meter (kV/m), in residential areas – 1.0 kV/m. It is very difficult to exceed it, as experts say, so in the “Soviet” version, lines up to 220 kV were allowed to be located as much as desired, and sometimes even built. Dacha settlements under high-voltage lines were quite common. Later, so-called power transmission line security zones appeared, designed to protect the structures themselves rather than the health of the population. One way or another, they took into account the distance from the house to the power lines.

Magnetism is worse than electricity

“Most of our practical studies confirm that the electric field strength near power lines does not exceed established standards. Regarding the magnetic field, everything is not so clear. The magnitude of the magnetic field depends on the currents passing through the wires, the material of the building walls, and even the design of power line supports,” said Oleg Grigoriev, director of the Center for Electromagnetic Safety, member of the Scientific Advisory Committee of the EMF and Health program of the World Health Organization (WHO). A number of Western studies indicate that living near power lines increases the risk of a number of diseases, precisely because of the magnetic component. Some results are alarming.

Thus, Swedish scientists have found that people living at a distance of up to 800 m from power lines with a voltage of 200 kV are statistically more likely to have leukemia, brain tumors, and breast cancer. In men, reproductive function decreases, and the percentage of births of boys decreases. The researchers found that all of these problems were to blame for the increased level of the magnetic component of the electromagnetic field, and estimated the dangerous threshold for magnetic flux density at 0.1 microtesla (µT).

Finnish experts came to a similar conclusion. True, they conducted research in a five-hundred-meter corridor from power lines with a voltage of 110-400 kV. Finnish scientists considered a magnetic flux density value of 0.2 µT to be a dangerous threshold.

Edge of risk

The WHO Agency for Cancer Research has classified power frequency magnetic fields (PFMF) with flux densities above 0.3-0.4 μT as Group 2B “possible carcinogens.” To make it clear, there is also group 2A (“probable carcinogens”) and group 1, which, in fact, includes absolutely proven carcinogens. WHO experts admit that the magnetic component of an electromagnetic field of industrial purity with a flux density higher than 0.3-0.4 μT “under conditions of prolonged chronic exposure may be a carcinogenic environmental factor.”

To be fair, we note that in the new millennium, Russian standards also finally “saw” the danger of the magnetic component of the field. SanPiN 2.1.2 1002-00 established the limit value of the magnetic indicator for residential premises at 10 µT, and for residential areas at 50 µT. On November 10, 2007, more stringent limits came into force, amounting to 5 and 10 μT, respectively. Alas, even these figures are tens of times higher than the “Scandinavian” threshold of 0.2 µT, which has become the official criterion for many countries.

“A number of countries have confirmed these standards by law. These are Switzerland, Scandinavian countries, Israel and some others. But Russia is not on this list. I consider it advisable for newly introduced residential facilities and for all school and preschool institutions to adhere to the WHO recommendations on this issue. Even if this does not have a hygienic justification, the WHO precautionary principle is precisely intended for such situations,” says Oleg Grigoriev.

So far, representatives of the scientific world cannot find a biological basis for the effects of IHRL on the human body. There is also a dissenting opinion. They say that power lines cannot have a significant impact on people's health, since at distances of 200 meters from the wires the magnetic field formed by them is less than the Earth's magnetic field, which is 30-50 µT. However, we should not forget that the magnetic field of our planet is relatively constant, and does not vibrate at a frequency of 50 Hz per second, like MPFC.

Enemies external and internal

When inspecting a property, you should not immediately panic if you find a power line nearby. First, assess her tension. In Russia, the most common power lines are 6, 10, 35, 110, 150, 220, 330 and 500 kV. You can determine what voltage a given line has indirectly by counting the number of insulators (in power lines up to 220 kV), or the number of wires in one bundle (“bundle”) for lines from 330 kV and above.

In areas of individual housing construction, 6-10 kV lines, less often 35 kV lines, run along the streets. You will have to come to terms with this (if a potential buyer is scared of even such power lines, you should think about moving to a non-electrified eco-village). A more serious danger is posed by power lines from 110 to 750 kV.

“And it’s not even about the electromagnetic field, or rather, not only about it. Power lines are a source of increased danger: hurricanes, broken wires, lightning striking power line supports - all of this, alas, cannot be excluded,” says Sergei Urzhumov, chief occupational health specialist from the Federal Service for Supervision of Consumer Rights Protection in the Novosibirsk Region.

If there is a choice, construction under power lines is, of course, undesirable. Theoretically, a residential building located near power lines can be protected. A grounded roof made of corrugated sheet metal or metal tiles and reinforcing mesh inside the walls protect well from the electric field (therefore, reinforced concrete walls are the best at attenuating radio waves). But the roof and grid must be reliably grounded. To suppress industrial-frequency magnetic fields, you may additionally need shielding with ferromagnets or multilayer “pies” made of special grades of steel.

But even if all this is organized and protected from external danger, do not forget that a refrigerator, an iron, and even a cozy home floor lamp will provide you with electromagnetic fields of industrial frequency in abundance. Look at the table below and you will understand - in addition to external electromagnetic “enemies”, there are many potentially dangerous internal sources in the house.

Propagation of industrial frequency magnetic field from household electrical appliances (above the level of 0.2 µT)

Power lines will go underground

If Russia, following developed countries, recognizes a dangerous IHRL level of at least 0.4 µT, this will seriously affect the real estate market, since a significant number of individual and apartment buildings, kindergartens and schools will find themselves in the zone of increased IHRL levels. The authorities will have to organize expensive work to reduce the level of the magnetic field. Perhaps the question will arise about moving one or another power line. However, in large cities, in particular in Moscow and St. Petersburg, programs have been developed to transfer power lines from the surface to the ground. This is largely done in order to free up expensive land plots currently located under power lines for development. In this case, the thickness of the earth can become a natural barrier to the propagation of electromagnetic waves, and it will become easier to achieve a safe level of radiation.

However, experts point out the danger of poor-quality installation of underground lines, since the cost of relocation is estimated at 1 million euros per 1 km, and developers will be tempted to save on safety. After all, if overhead power lines are always available for monitoring by operating and controlling organizations, then the underground, as you know, is a shady business.

But overhead lines can also be made safer. “Today there are projects of supports where, due to the suspension of wires, phase splitting, etc., vector field compensation occurs,” says Oleg Grigoriev.

Draw conclusions

According to most experts, it is still better to purchase or build a new house away from power lines. And not only because of the possible impact of IHRL. The “psi factor” can also play a huge role, when the real danger will be much less than the phobias of the residents.

“I’ll give you a funny incident. The owners of a country house noticed that after the construction of a mobile operator base station nearby, bees disappeared from the site, and the number of flies and wasps decreased sharply. Upon checking, it turned out that the station had not yet been connected at all. So many appeals are due to purely psychological reasons – suspiciousness and fears,” notes Sergei Urzhumov.

If a house or apartment is located near power lines and a potential buyer has doubts, you can call Rospotrebnadzor specialists and determine the levels of electric and magnetic fields. But since the level of the magnetic component depends on the amount of current in the wires, it is necessary to find out in advance from the energy company in what mode the power line is operating at the time of diagnosis.

Text: Mark Powerman Photo: Alexey Alexandronok

Determination of power line voltage indicator

In the process of planning the acquisition of a plot of land, you should make sure that the overhead lines are located at a safe distance from the proposed construction site. Such data is not always available, but you can find it out yourself by the number of wires and insulator disks near the pole.

Standards for placing overhead lines in various areas:

Determining the value of consumer voltage by the number of wires in the cable:

In this case, it is necessary to count not the number of cables, but the number of wires in a bundle of one of them. In addition, the height of the poles along which the wires are stretched will help you get your bearings: the higher the poles, the higher the voltage in the wires.

When there is one wire in the line, it is possible to find out the voltage indicator by the number of insulators, that is, ceramic disks on one branch. The standards here are:

• from 3 to 5 insulators – 35 kV;
• from 6 to 8 – 110 kV;
• from 15 – 220 kV.

How to determine the correct placement of a house when buying?

If a citizen decides to purchase or build a private house and, when viewing the building/site, he notices that there are power lines nearby, then before concluding the transaction and before starting construction work, he needs to check the distance.

Without knowing the power of the power line, it is impossible to verify the fact of compliance with the standard, since the minimum permissible distance changes. The easiest way to get acquainted with the necessary information is to submit an official request to the company that services the energy networks in the locality. However, a response to such a request will not be provided immediately.

There are also two other methods, but they both allow you to find out only approximate data:

1. It is necessary to look at the number of cores from which the power line wire is woven. They are thick enough that a person with good eyesight will not have difficulty seeing the weaving. Typically, the following types of wires are used:

• 1 core - up to 330 kV;
• 2 cores - 330 kV;
• 3 cores - 500 kV;
• 4 cores - 750 kV;
• from 6 cores - 1 kV and more.

2. You need to look at the number of insulators (round ceramic, less often glass disks):

• 1-5 insulators - line with power up to 35 kV;
• 6-8 insulators - 110 kV;
• 15 insulators and more - 220 kV and more.

On a note:

If the purchased property, in the buyer’s opinion, is located in a “border” area from the sanitary protection zone of the power line, then you should not conclude a deal by “learning” the power of the network by eye by the number of cores in the wires or by the number of insulators. To avoid further problems with registering ownership of real estate, resale of the property, etc., it is recommended to be guided only by official information. This can be obtained by sending a formal request to the energy company.

If a violation of sanitary standards has been identified, then it is worth familiarizing yourself with the dates of construction of the objects. If the power lines were built later than the house, then a formal claim should be sent to the energy company, as well as a complaint to the district/locality administration.

Typical voltage value in residential areas

Within the areas of residential areas, power lines have a voltage of 6 to 10 kV, and there is no generation of radiation that exceeds the permissible values ​​for people.

Power line supports and voltage indicators:

According to the provisions of SNiP, buildings for various purposes must be located 5 meters from the “red line”. Only a wire that is connected directly to the building can violate the safe distance.

The insulator securing the wire outside the building must be located on the wall of the building at a height of at least 2.75 meters. The entry of wires into the house should not be located above the entrance or near the rooms where people are most often. A safe place could be, for example, the wall of a utility room, pantry or hallway.

The sag of self-supporting insulated wires over a pedestrian path or walkway must be at least 3.5 meters, the sag between the supports of high-voltage lines - from 6 meters above the ground.

Pulling wires to connect a building from the opposite side should only be done using additional supports. In this case, the height to the insulators must be at least 6.2 meters, and the minimum horizontal interval from the overhead line with a voltage rating of 6 kV to high vegetation is 2 meters.

Electric lighting supports

6.3.8. The supports of lighting installations for squares, streets, and roads must be located at a distance of at least 1 m from the front edge of the side stone to the outer surface of the support base on main streets and roads with heavy traffic and at least 0.6 m on other streets, roads and squares. This distance is allowed to be reduced to 0.3 m, provided there are no public transport routes or trucks. If there is no side stone, the distance from the edge of the roadway to the outer surface of the support base must be at least 1.75 m.

In the territories of industrial enterprises, the distance from the external lighting support to the roadway is recommended to be at least 1 m. This distance can be reduced to 0.6 m.

6.3.9. Lighting poles for streets and roads with dividing strips 4 m wide or more can be installed in the center of the dividing strips.

6.3.10. On streets and roads with ditches, it is allowed to install supports behind the ditch if the distance from the support to the nearest border of the roadway does not exceed 4 m.

The support should not be between the fire hydrant and the roadway.

6.3.11. It is recommended to install supports at intersections and junctions of streets and roads at a distance of at least 1.5 m from the beginning of the curvature of sidewalks, without disturbing the line of installation of supports.

Methods of protection against magnetic fields

As you move away from power lines, the emitted magnetic field gradually decreases, but does not disappear completely. The normative provisions of SanPiN specify the distance when this value reaches the permitted value. According to experts, an absolutely harmless distance is approximately 10 times higher than the permissible values. Placement of poles near the home:

Dwellings built at a distance closer than 100 meters from lines with a household voltage indicator and 200 meters from overhead lines must be equipped with protection from the electromagnetic field.