Is a leaking transformer dangerous ?

As an industrial or construction professional, you may need to install electrical transformers on a construction site you are planning to start. If the worksite is already on-going, you should know that a transformer can represent certain risks, which it is however possible to manage effectively.

Among others, the installation of a retention bund equipped with a rainwater filter under an electrical transformer will prevent the oils leaking from the transformer installed outdoor to pollute soil and phreatic water. Here is what you need to know about the transformer retention bund, in order to fully understand how useful it can be. 

Is a leaking transformer dangerous

What is an electrical transformer and what is it used for?

An electrical transformer is a piece of equipment that transforms energy for later use. As mentioned above, the use of dielectric oil is imperative to ensure proper operation of the transformer, since it is used for internal cooling and to also insulate the transformer. Since the quantity of oil required is very large, you understand that it is very important to manage the risks of groundwater pollution and fire as well as possible.

You should also know that the energy needs of an industry may involve the presence of several electrical transformers when necessary, in order to be able to transform as much energy as possible. This also automatically increases the risk of fire or oil pollution.

Electrical transformers are important components in an industrial installation, because without them it would be impossible to have electricity. But the operation of a submerged transformer requires the use of dielectric oil, which can represent risks of groundwater pollution or even fire, as we shall see later. 

What are the risks associated with electrical transformers?

Hydrocarbon leaks from a transformer can thus pollute the drainage water which will be absorbed by the soil.

Likewise, rainwater falling on the transformer will also drain hydrocarbons and may pollute the soil. The installation, which is compulsory, of a hydrocarbon retention bund under each transformer, however, prevents any pollution risk, by blocking the oils thanks to a rainwater filter.

As there may be several electrical transformers installed to produce enough electricity, the quantities of hydrocarbons are substantial. This can therefore represent a considerable risk in the event of a leak!

The main risk is that transformer oils accidentally spills (leaks) into drainage water, and then lead to oil pollution of the soil, which is always a significant danger to the ecosystem. The oils will then mix with drainage water or with rainwater runoff and infiltrate deep into the soil, thereby polluting the soil and phreatic water. 

eletrical transformer fire

Likewise, a fire risk is also possible on electrical transformers. A transformer can burst into flames as in the photo below, in an EDF power station in 2019 in Villejust.   

To prevent these risks, there are effective solutions to implement. This requires the installation of protective equipment. AKHELEC is specialized in the design, manufacturing and installation of hydrocarbon retention bunds, filters and other equipment. Those are dedicated to protect electrical transformers against the risks of fire propagation and soil and groundwater pollution.

How to protect oneself from the risks associated with electrical transformers?

When starting a construction site or when you are about to install electrical transformers, you must be aware of the risks associated with electrical transformers, and protect yourself against them. Our company is specialized in the preservation of ecosystems, and offers you high quality products, which today equip a large number of installations in France, Europe, and around the world. Proper equipment is essential to fully comply with the laws relating to water treatment.   

Hydrocarbon retention of transformers bunds prevent pollution of soil and groundwater

Retention bunds are compulsory equipment, particularly effective in preventing soil and groundwater pollution. Indeed, the rainwater may drain transformer dielectric oil and get charged with hydrocarbons. Without an oil retention bund, the situation would be catastrophic.

The transformer retention tank

A retention bund for a transformer installed outdoors collects rainwater potentially polluted with dielectric oil. To be effective, the retention must be equipped with a FILTRELEC® filter. Such filter will continuously drain the rainwater outside the retention and at the same time capture traces of hydrocarbons.

Depending on your needs, you can also equip your installation with a flexible retention bund , a  metallic or concrete bund . An oil retention bund is essential in all installations with an electrical transformer to fight against soil pollution.    

But this bund can also be used to store barrels or containers filled with polluting, harmful or even toxic products for humans and the environment. Storing products in a retention bund thus prevents polluting and harmful products from spreading on the ground and poisoning humans at the same time!

At AKHELEC, we provide you with a suitable choice of hydrocarbon retention bunds and other equipment, so that you always find what is ideally suited for your electrical installation.

Avoid transformers oil leaks

We have the solution for transformers oil leaks with our product HOLYBAG.

It separates the oil from the water, collects hydrocarbons and disposes rainwater.

This is a mobile pollution prevention system in the event of oil leaks.

System developed in conjunction with the maintenance teams from RTE (company that manages the public high voltage electricity transmission network in France).

transformer oil leaks

Hydrocarbon and rainwater filter system

filtrelec filtration system for polluted water

To make the retention bund even more efficient, our company has also developed a filter (FILTRELEC F5), which can be installed on the retention bunds to filter harmful substances. The whole point of FILTRELEC F5 is that not only it manages the storage of any leaks of dangerous products in the retention bund, but also helps the treatment of these product leaks! It is also the very first rechargeable filter, which is very interesting in terms of cost and waste reduction.  

Indeed, unlike a normal filter which will have to be changed completely by a new one, the rechargeable F5 filter does not require the replacement of the entire filter! This AKHELEC filter is rechargeable directly on site. You only need to change the filtration media cartridge so that the filter can be used again. This saves time and guarantees cost savings. In addition, with just a filter cartridge to change, there is naturally less waste to dispose of.

Limit the risk of fire spreading with fire-extinguishing covers or fire extinguishing retention bund

AKHELEC markets a natural fire extinguishing device to prevent fire propagation. Here is all the fire protection equipment that you can find at AKHELEC, to ensure the safety of your installations at all times:

  • fire-extinguishing retention bunds ;
  • and a fire cover or fire extinguisher system.  


To prevent these risks, there are effective solutions to implement. This requires the installation of protective equipment. AKHELEC is specialized in the design, manufacturing and installation of hydrocarbon retention bunds, filters and other equipment. Those are dedicated to protect electrical transformers against the risks of fire propagation and soil and groundwater pollution.

BAF - Fire suppression containment bunds for electrical transformers

For your safety

AKHELEC specializes in the marketing of the bunds and filters that we manufacture. For your safety, we also take care of the installation of this equipment. Each can also be carried out by a company which must be approved by the AKHELEC Company, so that the Manufacturer’s Certificate of Conformity can be issued.

We recommend to call on our experienced staff security and specific clearance teams for all installation work. They will thus be able to guarantee you a job carried out perfectly within the standards. By purchasing at AKHELEC, you will also be assured of managing the risks associated with electrical transformers as well as possible.

When you plan to install solar plants equipment, we also advise you to be vigilant in the choice of equipment, and to place all your trust in our company AKHELEC. We have all the skills required to carry out your work, whatever it may be.

To protect yourself against the risks associated with electrical transformers and to equip yourself well, we invite you to contact us.