1. mi.ttu.ee Sustainable Groundwater Resource Management in Estonian Oil Shale Deposit Helena Lind Jüri R. Pastarus Tallinn University of Technology, Department of Mining Kalmer Sokman and Erik Väli Estonian Oil Shale Mining Company (Eesti Põlevkivi) Riho Iskül Kunda Nordic Cement Company

2. mi.ttu.ee 16-09-2007TUT Mining Department Content of the presentation Sustainability Is the groundwater resources management sustainable? Problems and impacts of oil shale mining Environmental taxes Are we sustainable? Can we be more sustainable? Conclusion

3. mi.ttu.ee 16-09-2007TUT Mining Department Sustainability Water quality, resource and environmental diversity remains while groundwater is used We predict the impacts in advance and use the best possible technological solutions Long term development

4. mi.ttu.ee 16-09-2007TUT Mining Department Impacts of the oil shale mining The main impact to the environment during mining and after mining: change of water regime: decreasing & increasing waterlevel change of groundwater chemical components

5. mi.ttu.ee 16-09-2007TUT Mining Department Hydrogeological and mining conditions Mines next to closed and water filled areas Oil shale outcrop area

6. mi.ttu.ee 16-09-2007TUT Mining Department Dewatering: pumping stations

7. mi.ttu.ee 16-09-2007TUT Mining Department Dewatering: pumping rate Pumping rate at 2006 was 155 million m 3 Precipitations 555 mm Data: Estonian Oil Shale Company

8. mi.ttu.ee 16-09-2007TUT Mining Department Dewatering: pumping rate per produced tonnage Data: Estonian Oil Shale Company

9. mi.ttu.ee 16-09-2007TUT Mining Department Dewatering: pumping rate Data: Kunda Nordic Cement company

10. mi.ttu.ee 16-09-2007TUT Mining Department Pumped mine water Analyse of 2006: 50-90% precipitations Recirculating water – water from closed mines Groundwater Methodology of analyse: Reinsalu, E (2005). Changes in mine dewatering after the closure of exhausted oil shale mines. Oil Shale, 22(3), 261 - 273

11. mi.ttu.ee 16-09-2007TUT Mining Department Changes in watertable Water level decreases

12. mi.ttu.ee 16-09-2007TUT Mining Department Water quality: microcomponents of water in mine IndicatorUnit Water in mine, 2004 Water in mine, 2006 Normatives of mineral water Normatives of drinking water Soodla water reservoir pH 7,17,44 6,5-9,58 NH 4 + mg/l0,0170,26 <0,50,005 NO 2 - mg/l0,0150,01 <0,50,003 NO 3 - mg/l11,76,4150 0,76 Cl-mg/l16,432,69200< 250 SO 4 2- mg/l342,436,1200< 25031,1 Ca 2+ mg/l174,5124,8150-53 Mg 2+ mg/l51,640,950-5 Total Femg/l0,690,481< 0,2 (1,0)0,27 Oil productsmg/l0,150,063 0.05 Total phenols mg/m3<0,001<0,003 < 0,0005 Data: Reinsalu, E; Valgma, I; Lind, H; Sokman, K (2006). Technogenic water body closed oil shale mines. Oil Shale, 23(1), 15 - 28. Estonian Oil Shale Company

13. mi.ttu.ee 16-09-2007TUT Mining Department Legislation Environmental taxes are increasing every year: Data: Estonian Oil Shale Company

14. mi.ttu.ee 16-09-2007TUT Mining Department Environmental taxes and sustainability Increasing environmental taxes has incentive effect: use new mining methods and technology, new environment protective technologies (infiltration dams) to pump out less groundwater to clean the water To be more effective, decrease losses -> to decrease usage of nature resources -> to decrease influence on environment and society (nearby living people)

15. mi.ttu.ee 16-09-2007TUT Mining Department Resources management To understanding the behaviour of a groundwater system and its interaction with the environment is nessesary to have a sustainable management plan Mathematical models supported by field information have a key role in assessing the future behaviour of a system to find effective operating conditions for sustainable development and management groundwater resources.

16. mi.ttu.ee 16-09-2007TUT Mining Department Groundwater modelling

17. mi.ttu.ee 16-09-2007TUT Mining Department Are we sustainable? Watertable recovers within 2 to 5 years after the pumping has stopped, The quality of waterfilled underground mine is close to natural groundwater limits within 5 years Data: Reinsalu, E; Valgma, I; Lind, H; Sokman, K (2006). Technogenic water body closed oil shale mines. Oil Shale, 23(1), 15 - 28.

18. mi.ttu.ee 16-09-2007TUT Mining Department Where can we be more efficient, sustainable? There can be techncal solutions to avoid water income – infiltration dams, permeable walls Clean the water to reach the drinking water quality Computational mathematical models can be used to allocate the technical and environmental constraints

19. mi.ttu.ee 16-09-2007TUT Mining Department Where can we be more efficient, sustainable? But, ->There is always question of money, what is more pofitable? is it cheaper to pump the water and pay the taxes or use new innovative solutions?

20. mi.ttu.ee 16-09-2007TUT Mining Department Conclusion Increasing taxes has affect to develop new innovative technologies to mine the maximum possible resources with less losses, in the same time avoiding expansive impact to the environment There can be used technological solutions to be more effective, environmentally friendly, sustainable

21. mi.ttu.ee Thank You for attention!

22. mi.ttu.ee 16-09-2007TUT Mining Department 1. Background information (1) Location:Estonian Oil Shale Deposit & & & & & ' ' ' ' ' ' ' ' ' OIL SHALE MINING AREA & & & & & ' ' ' ' ' ' ' ' '

23. mi.ttu.ee 16-09-2007TUT Mining Department 9. Results of the model (2) Groundwater table and contour lines at timestep 0.day Movie file green: groundsurface, blue/gray: watertable, brown: bottom of oil shale layer