Water use

Fortum uses large volumes of water at various types of power plants and in district heat networks. In most cases our power plants do not consume water, but the water is discharged back to the same water system from where it was withdrawn. The properties of the water may change in the process, but the volume of the water generally remains unchanged. In some cases, water is transferred to another recipient, e.g. through evaporation into the air from cooling towers, leaks into the ground from district heat piping, or through the discharge of wastewater to a municipal sewage system.

Hydropower production is a special case of water use. Water flowing in a river is conducted through a turbine to generate electricity. No water is consumed nor are the properties of water altered in the process. However, the water system is often regulated for hydropower production, and the regulation changes the water flow and level patterns compared to their natural state. Fortum does not report water flows in rivers as water use related to hydropower production.

Cooling water 

Condensing power production requires large volumes of cooling water. Cooling water accounts over 90% of Fortum’s total water withdrawal annually.
Fortum’s big condensing power plants in Finland are located on coastal area and use direct sea water cooling. No water is consumed in the process and the water withdrawn is discharged back into the sea. The only change is an approximately 10 °C increase in the temperature of the cooling water.
Condensing power is occasionally produced also at our CHP plants. In most cases, the cooling water is withdrawn from a local water system. In Russia and Poland, cooling towers are used, so some of the cooling water evaporates into the atmosphere.

District heating network

Fortum is a major supplier of district heating in Finland, Russia, Poland and the Baltic countries. Fortum has a total of about 2,700 kilometres of district heat pipes in these countries. Water is used as the heat transfer media in the district heat networks. Some water is lost through leaks that occur in the pipes, so occasionally water must be added to the district heating network.

Process water and other water uses 

A thermal power plant needs water in the water-steam cycle when electricity is generated with a steam turbine. Because of leaks in the pipes, occasionally water must be added to the water-steam cycle. Water is also needed in some auxiliary processes, e.g. in SO2 removal with wet scrubber technology and in liquid radioactive waste handling and storage at nuclear power plants.

Water withdrawal

The Baltic Sea and local fresh water systems are the most important water sources for Fortum’s water withdrawal. Municipal tap water is used mainly at CHP plants in major cities. In some cases, water is acquired from a near-by industrial facility of another company.
The majority of Fortum’s power and heat production capacity is located in Finland, Russia and Poland. Our thermal power plants are not located on a water critical area in any of our operating countries. Water is used to clean solar panels at our Indian solar power plants. Even though the water volumes are relatively small, alternative water sources and purification methods are being explored in India.


Wastewater generated at power plants is either treated at the power plants’ own wastewater treatment plant and discharged into a water system or it is piped to a municipal wastewater system for further processing. In Russia, the wet method is used to pump ash from power plants into ash ponds. Part of the water from the ponds is recycled back to the power plant and part is released into a water system after sedimentation.   
Wastewater contains solids and nutrients, like nitrogen, phosphor, and heavy metals. Wastewater effluents can impact local water quality as well as the nutrient and oxygen balance of the water system.

Water withdrawal in 2015

We withdrew a total of 2,138 (2014: 2,186) million cubic metres of water in 2015. Sea water accounted for 70% of this amount.

Water withdrawal in 2013-2015 (GRI G4-EN8)


Water use in 2013-2015 (GRI G4-EN8)

Of the water we withdrew, we used the majority, 2,060 (2014: 2,094) million cubic metres, as cooling water. The Loviisa nuclear power plant withdrew from and discharged to the sea 1,403 million cubic meters of cooling water.

The reported water withdrawal and water use volumes are based on flow measurements at power plants and heat plants.

Wastewater in 2015

Our plants generated a total of 34 (2014: 33) million m3 of wastewater, of which 96% was released into the environment after being treated and 4% was piped to municipal wastewater treatment plants. 

Wastewater emissions by recipient in 2013-2015 (GRI G4-EN22)


About 1.2 tonnes of oil was released into water systems with wastewater. In addition, 3.8 tonnes of oil was relased into rivers from hydro power plants. In recent years there have been frequent violations of wastewater permits at Russian power plants. They have been discussed in more detail on page Environmental incidents.
The thermal load discharged into water systems with cooling water was 17 (2014: 18) TWh. Loviisa nuclear power plant’s share of this was 16 TWh. Temperature measurements indicate that the cooling water has increased the temperature of surface water by 1–2 °C within a 1–2 kilometre radius from the discharge point.
The reported wastewater volumes are based on flow measurements at our power plants and heat plants.