Landscaping

Landscaping waste rock piles:

The remediation of waste rock was carried out after uranium ore mining was terminated. The smaller - appr. 100,000 m³ - waste rock piles were relocated to the main waste rock pile, which has a volume of nearly 10 million m³. Following the development of morphology, the piles were covered. The one-meter-thick soil covering ensures that radiation stays within set parameters, infiltration is minimised, and that the soil is thick enough for forestation. Contaminated water flowing from beneath the waste rock piles is collected in belt trenches and then it is treated.



Non-ferrous metal mining in Gyöngyösoroszi resulted in creating 23 waste rock piles. After a technical survey and an investigation of the composition of the waste rock piles were carried out, the work of landscaping commenced. The main consideration is to minimise the environmental risk stemming from the waste rock piles. The waste rock piles that are of a higher volume and have a composition carrying a higher environmental risk are relocated to the tailings pond in Szárazvölgy, where most of the contamination released can be collected in belt trenches and, if necessary, can be treated in situ or at a minewater treatment plant.

Landscaping heap leaching sites:

Crushed low-grade uranium ore was piled into 10-12-meter high heaps in basins that were insulated with a plastic liner. The uranium content of the ore was leached by alkaline solutions. As these heap leaching piles are located in the immediate vicinity of the drinking water catchment area supplying the town of Pécs, the residues have been hauled to a safer area, the main waste rock pile, to avoid groundwater contamination. The main waste rock pile is located above the former shaft so most of the seepage from the pile is collected by the shaft's cavities. The collected water is then pumped out in the form of mine water and is subsequently treated.

Landscaping tailings ponds:

During the time period of the uranium ore processing two tailings ponds covering 163 hectares were created for mill tailings. The ponds were built near a drinking water catchment area and had no bottom liners, thus a part of the technological solutions and the precipitation falling into them leaked further into the groundwater.



During the implementation of the remediation plan, first the morphology is developed, then a multi-layer cover (clay, sand, and loess) is placed over the entire surface of the tailings piles. The cover has to be minimum 1.5m thick, and the successive layers are built under constant technical supervision. It serves as a radon barrier (preventing radon gas emission), stops the dispersal of tailings and significantly decreases the dissolution of contaminants from the tailings. The covered and revegetated surface of the tailings piles prevents surface erosion and the disintegration of the structure of the multi-layer cover.

Closure of underground mine workings:

In the 42-year-long period of the Hungarian uranium ore mining, five mining plants were opened. The closure of these mining plants was regulated in the Act on Mining as follows: "underground mine workings that will not be utilised any longer shall be abandoned in such a condition that presents no threat to the environment or the surface". It was in compliance with the law that the soils contaminated with oil, grease, acid and alkali were removed and disposed of on the surface, and the contaminated machinery were taken out. A system of dams was built in the mine workings so as to ensure steady water build-up. It also attenuates the emission of radon gas.