Environmental threats and reclamation after underground mining 1

USJP Forestry 4th year presentations

1. Environmental Threats and Reclamation after Underground Mining: Specially focus on Gem mining R.M.T.D. M adusanka AS2012135

2. Underground Mining. Gem mining. Gem mining areas. Gem mining methods. Pit mines. Environmental threats of gem mining. Threats on water. Threats on soil. Threats on fauna and flora. Threats on humans Threats on Landscapes. Mine Reclamation. Gem mine Reclamation. Conclusion.

3. Mining The activity, occupation, and industry concerned with the extraction of minerals. Underground Mining Mineral exploitation in which the extraction is carried out beneath the surface of the earth Types of Underground mining. Drift mining. Slope mining. Shaft mining. Borehole process. Hard rock mining.

4. Graphite Mining. Gem Mining.

5. Gemstone mining is a traditional industry in Sri Lanka runs way back to the era of ancient kings. Even today traditional mining is the most common practice. (more than 6,500 licenses issued in 2013, more than 6,000 were for pit-mining operations using traditional methods) Currently Gem mining is under the regulatory supervision of the NGJA . A gradual rise in the use of light mechanized mining methods can also be seen in recent times . I llegal exploitable gem mining is also increased in recent times.

6. Traditional gem mining areas Ratnapura Pelmadulla Balangoda , Eheliyagoda Rakwana . Recently extended areas Elahera Bakamuna Passara Okkampitiya Kanthale Bibile Horana

7. Shallow circular pits. When Gem deposits are located near the surface. Depth of a shallow pit can be only few meters . Deep rectangular pits. May have a depth of over 50 meters . E xcavated horizontally creating tunnels extend from 6 to 9 meters

8. Environmental Threats of Gem Mining.

9. Contamination of rivers, lakes and waterbodies. Causes Discharge of muddy water , sediments, rubbish into hydrological environments. Washing of gem bearing soils in streams. Long-term consequences Reduce the reservoir capacities . Floods. Turbidity and salinity levels have effects on fauna and flora. .

10. Contamination of rivers, lakes and waterbodies. Mitigation Strategies Mud filtering systems can be introduced. -Sediment tanks -Slit traps

11. 2. Alteration of surface and ground water flow. Causes Unrestrained pumping of water for mining activity. Diversion of streams from the mining area . Long-term consequences Depletion of groundwater levels . Altered flooding patterns are. Unavailability of water for agricultural purposes.

12. 2. Alteration of surface and ground water flow. Mitigation strategies Re-diverting the streams following the cessation of mining. Regulating the excessive pumping of water.

13. Soil erosion and Instability . Causes Pilling of easily erodible subsoil in the surface. Mining in stream banks. Long-term consequences Siltation in streams & reservoirs. Collapsing the stream banks. Mitigation strategies Covering the piles of soil . Effective law enforcement.

14. 2. Loss of soil nutrition. Causes Bringing up the infertile sub soil in to the earth surface. Washing the soil in searching gems. Long-term consequences infertile soil Depletion of agricultural production. Mitigation strategies Limit damage to topsoil in the mining R emediate appropriately post-mining.

15. 1 . Loss of faunal and floral habitats Causes Deforestation. Complete uprooting of vegetation. Long-term consequences Biodiversity loss . Mitigation strategies Conserve the similar habitats. Regulate the behavior of labours .

16. 2 . Overuse of timber resources. Causes Reinforcing mining pits(Rubber & Arecanut ) Mine sheds.(Bamboo, Arecanut ) Long-term consequences Depletion of timbers in the market. Depletion of Arecanut production. Mitigation strategies Introduce Replanting of timber species. Use other common timber species. Reuse where appropriate.

17. 1. Contaminated water sources. Causes Muddy water from the mines. Long-term consequences Depletion of drinking water sources. Health problems for humans. Mitigation strategies Introduce filter systems.

18. 2. Safety hazard of pits during and after mining. Causes Improperly constructed pits. Improperly ceased pits. mine collapse . Gas poisoning. Long-term consequences Malaria, Dengue. Respiratory and skin diseases. Deaths.

19. 2. Safety hazard of pits during and after mining. Mitigation strategies Reinforcing pit walls. Pits and shafts should be closed properly after mining has ceased . Use of safety wears. Aerate the deep mines. P re-identification of possible gas poisonings.

20. 3 . Land-use conflicts. Causes Mining activities conflicts with livelihood activities. (Paddy cultivation, plantations) Long-term consequences Social and economic Problems. Mitigation strategies I mprove s takeholder participation in planning mining activities.

21. 4. Damages to the man made structures. Causes Digging in roadsides Depletion of water table by pumping of water. Long-term consequences Cracking the soil and walls of houses. Erosion of roads. Mitigation strategies Set the limits for dewatering mines. Law enforcement.

22. Landscape destruction . Causes Constant pitting and trenching. Long-term consequences Unstable deteriorated landscapes. Mitigation strategies Pits must be reclaimed properly after mining. Regulate the mechanized mining.

23. Reclamation of Gem Mines.

24. Mine reclamation is the process of restoring land that has been mined to a natural or economically usable state. After any mining activity landscapes are altered and the ecosystem totally disrupted. Two options in reclamation, Restoring the pre-mining land use. Change the land use to another.

25. The first task in developing an effective mine reclamation program is to set a clearly defined post-mining land use objective. It should be compatible with surrounding land use. It should support biodiversity. It should be consistent with the expectations of the local community and the landowners. R egulatory agencies must agree with it.

26. For the most Gem mined area, restoration of the pre-mining land use is the best suited method. Because, most of gem mines are in the paddy fields, forested areas and stream banks. Permanent alteration of those land uses is not accepted.

27. Reclamation plans should implemented as soon as areas become available . The disturbed mined areas need to be returned to a safe and stable physical state. Pits should be closed. Soils are stabilized. R isks to humans, domestic animals and wildlife minimized.

28. Then suitable vegetation can be established or facilitate the natural succession. Outcome will be, Restoration of habitats. Conservation of soil. Increase the productivity. Restore the scenic value.

29. About 90% of the gem mining is carried out in alluvial deposits using traditional methods. Despite the relatively high economic and social benefits gem mining cause significant environment damages. The damage on the environment from the industry is gradually rising with the illegal gem exploitation and the recently introduced mechanized methods for mining.

30. National Gem And Jewellery Authority Act No 50 of 1993. Mines And Minerals Act No 33 of 1992. Guild lines for natural resource management, CEA Rehabilitating mines to meet land use objectives: bauxite mining in the jarrah forest of Western Australia by J. Gardner MEASURES TO REDUCE ENVIRONMENTAL IMPACTS OF GEM MINING D.K.N.G. Pushpakurnara ' and H.C. Panditharathna / CAN TRADITIONAL METHODS BE STILL USEFUL IN EXPLORATION AND MINING OF GEM DEPOSITS? - A REVIEW , S.W . NAWARATNE Environmental Stewardship in G emstone Mining by David Suzuki . http://www.fao.org/docrep/004/y2795e/y2795e03.htm Official website of Geological survey and Mines bureau http://www.gsmb.gov.lk/ Official website of National Gem and Jewellary Authority http:// www.ngja.gov.lk/en/ q