Water management

Processes related to water and wastewater management in PGE Group installations are carried out mainly on the basis of the Water Law Act and other executive acts dedicated to water and wastewater management. They are carried out in accordance with administrative decisions issued by competent authorities, such as integrated permits or sectoral decisions (water permits). The PGE Group continuously monitors the quantity and quality of water abstracted and wastewater discharged in accordance with administrative decisions issued in this respect.

For technological needs of installations within the PGE Group, water from surface water intakes is mainly used after undergoing purification processes. In order to reduce the amount of raw water consumption, closed circuits are used in the majority of cases, and used process water and wastewater are introduced to other processes. Wastewater generated by production operations undergoes treatment, including multi-stage treatment, and is then discharged to surface waters or transferred to municipal enterprises.

Conditions for water and wastewater management are set out in relevant permits, including mainly integrated permits and water permits. The Branches of PGE GiEK SA carry out ongoing monitoring of the quantity and quality of water abstracted and wastewater discharged.

For technological purposes, water from surface water intakes is used and subsequently undergoes purification and treatment processes, with the exception of the Szczecin CHP plant which uses internal sea water. In order to reduce raw water consumption, closed circuits are used and used process water and wastewater are introduced to other processes. Wastewater generated by production operations in power plants and cogeneration plants undergoes treatment, including multi-stage treatment, and is then discharged to surface waters or transferred to municipal enterprises.

Depending on environmental conditions, the branches utilise appropriate water treatment and wastewater treatment technologies to ensure compliance with all environmental requirements. Adaptation to the requirements of the BAT conclusions in PGE Górnictwo i Energetyka Konwencjonalna means also the reduction of emissions to water from flue gas purification systems utilised in the process of electricity generation. In this respect, wastewater treatment plants undergo modernisation and extension processes.

At the Dolna Odra Power Plant and Pomorzany CHP Plant, surface and underground water is abstracted, whereas at the Szczecin CHP Plant, internal sea water is abstracted. All active groundwater intakes are surrounded by direct water protection zones. The power plants of the branch are equipped with facilities to reduce pollutants contained in wastewater. Depending on the type of wastewater, it is treated in a chemical or biological treatment plant, in a mechanical treatment plant, or it is neutralised. Depending on the composition of wastewater, it is treated in one or two facilities. Rainwater and snowmelt from the branch premises are treated by means of settling tanks and separators.

The Turów Power Plant closes water circulation in production processes by diverting used water for treatment and subsequently returning it to production processes. The construction of a wet flue gas desulphurisation plant for the new power unit no. 7 in Turów is currently underway. Wastewater treated in the plant will be reused in technological processes. In order to reduce water consumption and the volume of wastewater discharge, water from the desalination of the main cooling system or, in emergencies, water discharged from the compressor cooling system is used instead of raw water for most of the year to supply water to the flue gas desulphurisation plant for units 4-6.

It is a measure aimed at improving the environmental conditions in the surroundings of the Turów Complex and ensuring the Turów Power Plant’s compliance with future EU and national environmental requirements.

The planned industrial wastewater treatment plant will be based on modern, highly efficient membrane technologies such as microfiltration and reverse osmosis. The efficiency of reverse osmosis is approximately 96-98 percent, which means that over 96 percent of all pollutants will be retained in the process. This will be the first in Poland and one of few in the European Union such a wide application of the aforementioned technologies in the field of wastewater treatment. Thanks to this project, the Turów Power Plant will be the first power utility to reuse treated wastewater in its technological systems. Consequently, it will be a wastewater-free power plant. The new wastewater treatment plant will be the largest in the Polish energy sector. It will use membrane technologies with a total capacity of over 14,000 m³ per day. The implementation of this investment will have a positive impact on the border river Nysa Łużycka.

At the Opole Power Plant, all wastewater from plant’s premises is treated in a final wastewater treatment plant. Some types of industrial wastewater are subject to multi-stage treatment. Industrial wastewater and rainwater are directed to the final mechanical-chemical wastewater treatment plant, where they undergo the coagulation process. Wastewater from households is treated using the activated sludge method in a biological system also located at the final wastewater treatment plant. Treated industrial and domestic wastewater is discharged through a common carrier pipe to the Odra river. In order to improve the sedimentation of inflowing suspended solids in raw wastewater and to improve and automate the discharge of sediments to the sedimentation plots, a new radial settling tank with an integrated coagulation chamber was built in 2019. The new settling tank increased the operational reliability of the wastewater treatment plant and created a reserve capacity for the equipment at the treatment plant. The new settling tank operates as a primary element of the wastewater treatment system. The design capacity ensures the capture and treatment of the incoming wastewater flow of up to a nominal volume of 3200 m³/h and has a hydraulic reserve.

In order to reduce water consumption and the volume of wastewater discharge, water used in the Bełchatów Power Plant is reused in closed internal circuits and is not discharged outside the system. Used process water is reused in slagging operations and to replenish losses in the hydro ash removal system. Domestic wastewater and rainwater or snowmelt are moved to the wastewater treatment plant of the Bełchatów Lignite Mine Branch.

At the Rybnik Power Plant, all wastewater from the power plant premises is processed in wastewater treatment plants: an industrial wastewater treatment plant and a flue gas desulphurisation plant wastewater treatment plant. The Rybnik Power Plant uses closed water circuits wherever it is possible. The power plant does not reuse any treated wastewater due to the fact that water from water intakes is used in internal processes and only when there is no possibility to use it is discharged as wastewater.

The extraction of lignite deposit based on the opencast method, carried out in the Bełchatów and Turów lignite mines, requires prior drainage of the rock mass, which has a significant impact on hydrogeological conditions and results in changes in hydrodynamic relations. Water management in lignite mines is connected with both sunk drainage and face drainage of open pits. Water from pits is discharged to field settling ponds for final purification by natural sedimentation of suspended solids supported by a plant filter or to dedicated treatment plants. Each of the opencast lignite mines operated by PGE conducts planned water protection activities. Drainage facilities used to ensure water purity are being expanded and modernised.

Drainage water in the Bełchatów Lignite Mine is captured in pits and discharged through ditches to settling ponds. The concept of settling ponds is based on the technology of natural suspended solids sedimentation supported by a plant filter. Water from sunk drainage is discharged through a system of ditches and canals in quantities and with physical and chemical parameters that do not exceed the statutory limits specified in the applicable water law decision. Water discharged to surface watercourses maintains at least class II purity. In order to protect water purity in the existing natural watercourses of the region, the Bełchatów Lignite Mine operates mechanical and biological wastewater treatment plants.

For water protection, it is important to operate the following facilities:

• sedimentation ponds for face drainage water,
• a protective barrier for the “Dębina” salt dome to maintain an even water level in the rock mass surrounding the salt dome.

In 2020, the Turów Lignite Mine Branch discharged mine water coming from face drainage of the pit, as well as well water and domestic wastewater into external watercourses. The quality of well water allows its direct discharge into external watercourses. Mine water and domestic wastewater were treated at five on-site wastewater treatment plants. The branch’s mine water treatment plants are equipped with the Actiflo system. It is a highly effective process for reducing suspended solids. The volume of mine water discharge depends on the level of precipitation. In 2020, it was approximately 10 million m³. The parameters in terms of quantity and quality of discharged wastewater are determined by the requirements specified in the applicable water permits. The quality and quantity of discharged water and wastewater are monitored on an ongoing basis.

In PGE Energia Ciepła, both surface and underground water is used to produce process water. Several plants also use water from municipal water supply systems. Depending on the size of the plant, the source and composition of raw water, different water preparation techniques are used, such as lime softening, filtration, ion exchange, ultrafiltration, reverse osmosis and electrodeionisation. In each case, the complete water preparation sequence consists of a combination of several of the above techniques.

Water is prepared for the needs of a variety of systems, and its main points of reception include the following:

• district heating networks,
• water and water/steam systems of heat generation units,
• closed cooling systems,
• wet flue gas desulphurisation plants.

Depending on technological requirements, water is supplied to reception points after various stages of preparation. At each stage of water preparation, particular attention is paid to its reasonable use. Many wastewater streams generated in the course of water preparation are returned to the process. An example of this is reuse of filter washings, water recovered from post-softening sludge, concentrates from reverse osmosis or electrodialysis processes, or regenerated brine from the softening process. As far as its composition allows it, wastewater generated in other installations is also returned to the process.

Examples of this include the following:

• returning so-called hot wastewater as a source for the water preparation process,
• using frequently rainwater or drainage water for water production,
• returning treated wastewater coming from the desulphurisation process to the desulphurisation process if its composition meets the required criteria, which directly depends on the quality of combusted coal,

• using part of domestic wastewater after treatment as a source of water to replenish losses in the closed cooling system (Kraków CHP Plant). Work is underway to use treated wastewater from the municipal treatment plant as a source of process water,
• using wastewater as a source of water for process water systems or for replenishing water in ash and slag removal systems.

Among the more stringent requirements of the BAT conclusions concerning nitrogen and sulphur oxides removal, requirements were introduced concerning the parameters of wastewater from wet flue gas desulphurisation plants. The most important parameters include concentrations of metals and metalloids in wastewater. In order to adjust the wet flue gas desulphurisation plants functioning in Cracow, Wrocław, Gdańsk and Gdynia, a number of measures have been planned to increase the efficiency of the wastewater treatment process accompanying this desulphurisation method. The existing flue gas desulphurisation plants are equipped with highly efficient wastewater treatment systems. However, due to the requirements related to the reviewed BAT conclusions, their operation will be further optimised. Consequently, wastewater will meet the required parameters, and at the Gdynia location, a modern and proprietary technology of heavy metals capture based on the INNUPS method will be additionally implemented. This technology was developed within the scope of a research and development project. It is an example of the widest possible reuse of produced anthropogenic minerals and precious elements, in line with the principles of a circular economy applicable in the PGE Group.

PGE Group companies that do not conduct production processes use water only for current administrative needs.