Lessons learned from restoring large scale mining induced water regime in Germany - Best Practice in Coal Mining -

Transcription

1 Lessons learned from restoring large scale mining induced water regime in Germany - Best Practice in Coal Mining - Mine induced water regime Flooding post mining open casts Innovative techniques for water treatment Solutions resolving ground water rise Conclusion and lessons learned Dr.-Ing. Friedr.-Carl Benthaus, LMBV Strategy and Development Dr. Friedrich von Bismarck, Head of Joint-Governmental-Agency for Coal Mine Rehabilitation

2 Where are we? Lausitzer und Mitteldeutsches Braunkohlenrevier

3 Here we are: Lignite mining areas in Eastern Germany Berlin A 2 Magdeburg A 13 Brandenburg Sachsen- Anhalt A 14 A 9 A 9 Cottbus Poland Halle A 13 A 38 Thüringen Leipzig Sachsen 4 A 4 Lignite area Mine in operation Mine closed motorway Weimar A 4 A 4 A 9 A 9 Gera 4 Chemnitz Dresden Czech Republic.

4 Lignite mining in soft rock conditions Direction of progress Recultivation Spreader Coal shovel Relocation Overburden conveyor Intermediate Greening Overburden conveyor bridge F60 Site clearance Overburden excavator Conveyor belt system Filter wells Coal conveyor Overburden Dump Lignite seam Groundwater rising Groundwater lowering Quelle: VEM/LMBV

5 Lignite coal mining in the south of Leipzig Impacts on - Landscape - Communities - Housing areas - Infrastructure - Water regime -

6 Remediation following mining activities

7 Partners of LMBV mbh Board Federal Ministry of Finance Federal Countries (Länder BB, S, S-A, Th) Steering- and Budgetary Committee (State and Countries) Regional Remediation Advisory Councils - Supervising of Company / Business - Funding - Budget - Funding - Regional Planning - Approval of Projects - Controlling -Participation in Rehab.- Planning and Reutilisation Transparent, reliable, efficient Mining Authorities Environmental-, Water-Authorities Job Center Contractors Vattenfall MIBRAG ROMONTA - Supervising - Licensing of Management Plan - Approval procedure - Supervision - Allocation of Unemployed - Tendering - Construction work - Commitments - Collaboration

8 Folie 8

9 Organisation of the governmental remediation programme 1st. Level Steering- and Budgetary Committee (StuBA) with Joint-Governmental-Agency for Coal Mine Rehabilitation => Financial controlling 2nd. Level 3 rd. Level Lausitzer und Mitteldeutsche Bergbauverwaltungsgesellschaft (LMBV) => Geotechnical legal planning and technical controlling Civil engineering enterprises => Mass moving, stabilization, construction work

10 Changing landuse before - while - after mining 1850 Quelle: LMBV V20

11 Changing landuse before - while - after mining Quelle: LMBV V20

12 Changing landuse before - while - after mining 2015 Quelle: LMBV V20

13 Solution: Flooding of 200 small and 51 big post mining end lakes By ground water inflow + deviation of surface water Reducing Deficit Surface waters and Ground waters from 13 bill. m³ to 3,6 bill. m³ Ameliorating Water Quality (AMD) ph: 6 8 Fe: < 3 mg/l SO 4 : mg/l

14 Transition from Berzdorf mine to lake Berzdorf Flooding Berzdorf lake from 2002 to surface: 930 ha - volume: 330 mill. m³

15 Ilse Lake Lausitz Lake District Sedlitz Lake Skado Lake Blunoer Süd Lake Sabrodt Lake Spreetal Lake Senftenberger Lake Koschen Lake Bluno Lake Total Lake Area: ha forest area agriculture area natural preservation end lake commercial areas Scheibe Lake

16 Wine yard at Geiseltal Lake

17 Land slide and acid mine drainage near Kittlitz 2011

18 Hydrological and chemical problems Influence of mining to water quality Groundwater level after ending lowering of groundwater Acidification by oxidation of pyrite FeS / 2 O 2 + H 2 O Fe SO H + water soluble Inflow from the groundwater: rich on solved Iron 2+ rich of sulphate high acidity (ph: 3 4) dump

19 Development of innovative processes for treatment of acidic water: pilot and demonstration projects Mine dump Mine End Lake Outflow watercourses Groundwater in Situ aquifer treatment by Microbial Sulfate Reduction Skado Damm Reducing precipitation by caping Witznitz dump area Liming by mobile ships on lake Burghammer, lake Scheibe, lake Hasselbach In-lake Neutralization of Lake Bockwitz with soda ash Amelioration of liming by injection of CO 2 at Lake Burghammer HDHC Water treatment plant experiment Sulphate reduction Ground water inflow Lake water Outflow water

20 Innovative in-lake liming by mobile entities (ships) 1. Lake water liming techniques by treatment ship floating on lake surface: 2. injection under water ameliorates the effectiveness of raw materials up to 80% Pilot- and Demonstration test of applicable techniques at Lichtenau lake 3. Test on hydrogen carbonate buffering with CO 2 and lime are underway Quelle: BRAIN-LUG

21 Water deficite after 50 years mining: 13 bill. m³ Maximum water depression cone at Leipzig area km² Maximum water depression cone at Lausitz area km²

22 Iron rich inflows following ground water rise Groundwaterinflow: ca. 50 L/s Groundwaterinflow: L/s Groundwaterinflow: L/s Groundwaterinflow: 100 L/s Auswirkungen der Exfiltration in die Spree, IWB Uhlmann 2012 Fe gesamt - Konzentrationen

23 Iron in the River Spree Ecological consequences: water plants - lack of light mussels smother by fine silt fishes mud accumulation (spawning grounds)

24 Social Disputes Investigation upon depositing iron bog in post mining lakes Published by LMBV via internet Water treatment plant Vetschau Protesters at town hall and parliament

25 In-Situ aquifer treatment through microbial iron reduction In-Situ treatment at the inflow to the Spree river FI:B Mikrobiell induzierte Eisenretention zu Fließgewässern: Pilotprojekt Ruhlmühle 20142

26 Mitigation of hydrological regime in mining landscape Pre-Mining Situation Phase of Mining Post-Mining Landscape v. Bismarck 2014

27 Lessons learned from remediation in East Germany 1. Mining operations have an huge impact on waters and environment. There is a corresponding need for appropriate forms to reduce impacts. 2. Integrating remediation into the mining process, technical and financial effort will decrease subsequently. 3. Mining industry s image and reputation is greatly enhanced when it adopts best practices of environmental governance. 4. Remediation strategy simply green is not sufficient. 5. Post mining landscape and water regime will never been pre mining. => Remediation is an opportunity to promote structural change and create new landscape that achieve sustainable development.

28 Lessons learned from restoring large scale mining induced water regime in Germany - Best Practice in Coal Mining - Glückauf fc.benthaus@lmbv.de bismarck@gs-stuba.de