Responsibly and safely - managing mine water inflows at KGHM

KGHM’s copper mines have been facing water hazards since the beginning of their operations and are able to operate under such risks. Changes in underground water inflows have not threatened the operation of mines or the safety of workers, and have not limited production. KGHM has been investing and carrying out preventive measures related to this problem for years. It is worth emphasizing that mine water inflow is a natural phenomenon and is not due to human error or any negligence.

At KGHM, regular monitoring of hydrological conditions and the technical performance of facilities and infrastructure is carried out. Ongoing upgrades and repairs, as well as

actions aimed to reduce the inflow of underground water are carried out. The company is steadily increasing its technical capacity to pump water to the surface.

Among other things, the Polkowice-Sieroszowice mine is carrying out rock mass injection activities to reduce inflows. The mine is in the process of commissioning another so-called Main Dewatering Pumping Station at the SW-4 shaft. Its task is to pump water to surface reservoirs and then further to the surface pipeline network of the Tailings Plant. The pumping station is located relatively close to the site of water inflow to the workings, which simplifies the dewatering system.

Technological commissioning of the first stage of the Main Dewatering Pumping Station at the SW-4 shaft began in mid-2023. The acceptance procedure for the first stage of the pumping station is currently underway while testing the technical solutions used. At the same time, work is being carried out on the second stage of construction of the pumping station.

Within a few years of the first signs of water inflows from the main dolomite stratum, more than a dozen kilometers of underground boreholes were drilled at the Polkowice-Sieroszowice Mining Facility to identify the water hazard, in particular the paths of water migration in the rock mass. Underground reconnaissance allowed the first injection hole to be selected from the surface to reduce the quantity of the incoming water. Initially, the injection treatments, carried out since August 2023, helped reduce the rate of inflow increase, and for the last six months have kept inflow steady. More openings are planned.

The phenomenon of increased water inflow in the mines appeared in 2021, and to date the company has carried out a number of projects that have adapted the technical infrastructure to the situation. In 2023, a permanent Team for the Odra River was established at KGHM, which is responsible, among other things, for obtaining new water-law permits and for monitoring the compliance of the activities undertaken with the issued permits. Initiatives have also been taken to, among other things, secure the lawful management of mine water. The initiatives included an amendment to the water-law permit for the Tailings Plant, KGHM’s division. In October last year, the company obtained a new permit allowing safe operation of hydrotechnical facilities with a reduced environmental impact.

In addition to investments projects related to the development of hydrotechnical infrastructure, activities are also carried out to reduce the level of salinity of underground waters. Currently a feasibility study for the construction of a salt brewing plant is in the final stages of completion. In the next stage, investment decisions should be made. Research and testing of pilot salt content reducing plants are also underway.

With regard to the monitoring of the hydrotechnical infrastructure, including the Żelazny Most Tailings Storage Facility, measures have been taken in accordance with applicable laws, including:

• a study of the amount of atmospheric precipitation at a meteorological station representative of the location of the Żelazny Most Facility
• testing of indicator substances and parameters in surface, leachate, and underground water from the list specified in the water qualification regulations
• measurement of underground water levels in observation wells
• measurement of leachate water volume
• control of the amount of discharged wastewater
• quality control of the discharged wastewater
• control of the water quality of the Odra River

At KGHM Polska Miedź S.A., we emphasize that in recent years there have been no incidents related to the pumping of water out of mines, hydrotechnical infrastructure for tailings management, and water management that would threaten the safe conduct of business operations.