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| Flooding |
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| Early decommissioning of the large network of mining adits,
shafts, drifts, and galleries, and preparing the mines for flooding and
eventual closeout has been a priority on the agenda of Wismut GmbH. The
primary objective was to eliminate surface damage or subsidence and to
minimise adverse environmental impacts due to ground water. Flooding of
the mines was identified as the most environmentally friendly, technically
safest, and low-cost remedial option. Once mine water pumping is terminated,
the ground water will rise to its natural level. |
| Following termination of uranium mining, activities at the Ronneburg site in East Thuringia switched to mine decommissioning and close-out, just as at any other mining or milling site operated by SDAG Wismut. Approximately 27 million cubic metres of open mine workings and 40 shafts had to be prepared for flooding. This involved removal of grease/oils and of hazardous chemicals from underground mines, backfilling and sealing of day shafts and near-surface mine voids, and construction of about 120 hydraulic barriers. Flooding of mine workings occurs in two hydraulically separate systems: flooding of the mine fields located south of the A 4 motorway was initiated at the turn of the year 1997/98, that of the mine fields located north of the |
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A 4 began in January 2000. By the beginning of
June, 2004, the flood water level in the southern mine fields had risen
to approx. 200 m a.s.l. and that in the mine fields located north of
the A 4 to approx. 210 m a.s.l..
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