Mine flooding in Saarland

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The mine flooding in Saarland is a pilot project to flood disused coal mines in Saarland .

introduction

Due to safety and profitability deficiencies, several coal mines in Saarland were closed in the 1990s. The last mine in Saarland, the Saar mine in Ensdorf , was closed in 2012. One reason for the final cessation in 2008 was a tectonic earthquake in the Saarlouis district with a magnitude of 4.5. The cause was sandstone ceilings under which the coal was extracted and which then collapsed.

An important measure in coal mines is dewatering , i.e. the permanent pumping out of accumulations of water caused by rain, underground water reservoirs, etc. This dewatering must be continued even after the pits have been closed, as the rising water level endangers the stability of the subsoil, which can lead to building damage , waterlogging of the soil and the escape of radon . Another potential hazard lies in highly toxic substances, some of which are naturally present, but to a large extent have also accumulated through coal extraction methods such as PCBs and the like. If the pits were flooded, the rising groundwater contaminated with the toxins could mix drinking water layers.

First mining considerations

As early as 2006, the Federal Office of Economics and Export Control had commissioned the auditing company KPMG to estimate the cost of the perpetual obligations due to the closed coal mines. The operators of the coal mines in Saarland were obliged to pay the follow-up costs of the perpetual obligations. The expert opinion basically assumed permanent pumping, since no empirical values ​​were available for the potential risks. In the event that the pumps were to be stopped, however, corresponding cost discounts were estimated in advance (KPMG report, p. 70). In the report it was pointed out that shutting down the pumps would only be conceivable if all shafts had been renovated. The RAG had once will not go into, according to the experts, the risk of contamination of drinking water, and went from an unlimited water drainage from (KPMG report page 64). However, they considered a groundwater uplift up to approx. –400 m above sea level as tolerable.

In the appraisal, the cost of the mine drainage management accounted for around five billion euros in the cost estimate for mining operations, including one third of all costs incurred, including personnel management, pensions, mining damage, etc. (KPMG report, p. 100). About one sixth of these costs were accounted for by mine water management in Saarland. These figures make it understandable why RAG ultimately preferred flooding the pits.

In order to meet the future obligations of the mine operators, RAG AG and Evonik , the latter the “white area” of the companies acquired, were merged under the umbrella of the RAG Foundation in 2007 . Their main purpose was

"... the adjustment, control and support of the German hard coal mining of RAG Aktiengesellschaft (called" RAG "in these articles of association) depending on the legal and other framework conditions for the termination of subsidized mining of hard coal in Germany. This also includes support in the elimination and avoidance of consequential burdens from RAG's hard coal mining for the environment and nature within the framework of legal obligations ... "

In the preamble it says:

"With the proceeds from the capitalization of the investment area, the foundation will take over the financing of the mining obligations of RAG AG from the perpetual obligations on a permanent basis."

RAG and Evonik were to partially finance the foundation. Government funding for hard coal mining was planned until 2018.

In view of the uncertainty about the consequences of the flooding, however, resistance to this project grew in Saarland. Above all, the Saarland feared irreparable contamination of the drinking water layers. The pits are currently being pumped out and discharged into streams that empty their cargo into the Saar .

At the end of 2012, the RAG applied for the flooding of the Saarland mining fields Primsmulde , Dilsburg and Nordfeld up to approx. –400 m above sea level to the responsible mining authority in Saarbrücken as part of a special operating plan. The Oberbergamt des Saarlandes, however, rejected the request, in particular the design as a special operating plan . The declaration as the final operating plan would have been correct . The State Office for Environmental Protection and Occupational Safety was also against flooding because the risks would be too great and unmanageable. The mining authority, which is subordinate to the state government, nevertheless approved the application.

In February 2013 the decommissioned Saar mine was closed under the direction of mine director Friedrich Breining, with the intention of being final. The manholes were to be partially filled and sealed and dammed with concrete structures. A monitoring system for the controlled flooding of the mine was to be installed in Ensdorf to prevent possible mining damage. It was hoped that the supply of combined heat and power plants with released methane and a pumped storage power plant with a head of approx. 850 m would generate profitable energy, but this turned out to be uneconomical.

Proposal for the pit flooding

In February 2014, RAG announced its plans for the pit water in a two-stage pit water concept: In the first stage, the Reden pit was to be flooded, mainly because drainage was the most expensive here.

“Based on the status quo, phase 1 of the mine water concept provides for the dewatering Reden to be discontinued and the mine water in the water province of Reden to rise from –600 m asl by 280 m to –320 m asl, with overflow into the water province of Duhamel. This will require a period of three to four years after approval. Currently in Reden, by far the largest volume of mine water, at 13.9 million m³, is being pumped into the Saar via Klinkenbach, Sinnerbach and Blies near Saargemünd. After phase 1, these tributaries of the Saar would in future be free of mine water over a length of 87 river kilometers. "

In the second step, the remaining pits were to be flooded so that joint discharge of the pit water would then be possible via the Duhamel pit in Ensdorf into the Saar:

“To this end, in a later phase 2, the remaining water holdings Luisenthal , Viktoria and Camphausen , which currently pump around 3.9 million m³ of pit water together, are to be gradually discontinued in order to allow the pit water to rise further. In this way, a uniform mine water level would develop in the entire Saar area. At the Duhamel site near the Saar, the pit water will finally reach the surface after 2035 at a water level of around + 190 m above sea level. From there it can be fed into the Saar without using pumps. "

Problems with the pit flooding

In the following months, however, concerns about mine flooding grew: According to listings by the Ministry of Economic Affairs and RAG, around half a million cubic meters of fly ash from flue gas desulphurisation systems in hard coal power plants had been stored by 2012 . They were used as a building material by adding cement. As a further desulfurization product, spray absorbent ash was used in the event of a smoldering fire underground. In addition, several thousand barrels of asbestos cement were disposed of in the Reden mine until the 1990s . Another burden is foundry used sands, which were used to fill a shaft in the Luisenthal mine.

In January 2015, “ Der Spiegel ” announced that highly toxic hydraulic oil containing PCBs had been used in mining in the 1970s and 1980s . More than 10,000 tons of this carcinogenic substance were still stored in the shafts, in containers, abandoned facilities or spilled on the ground. Over 1500 tons of this poison were consumed in Saarland, but there are no documents available that document proper disposal, which suggests that a considerable proportion has and will get outside in an uncontrolled manner. RAG was also unable to provide reliable information about the amount of PCB in question underground.

Finally, the Group of the Greens requested a parliamentary committee of inquiry into the mine flooding. With the votes of the left and pirates, the required number of votes for the committee of inquiry came together. His goal was "the behavior of the state government, its members and the subordinate authorities in connection with the approval and assessment of implemented and planned mine water management measures in Saarland and the role of RAG AG and RAG-Stiftung in these decisions" examine. Its first meeting took place in May 2015.

Meanwhile, affected communities in the narrower flood zone, especially in the Saarlouis district, got involved in the current discussions.

The Nalbach municipal council decided unanimously to appeal against the flooding in Primsmulde and Dilsburg, which was approved in 2013. In particular, the special operating plan was criticized. On April 15, 2015, the RAG resumed pumping of the two mines mentioned, but expressed confidence that the mining authority would reject Nalbach's objection.

In July 2015, the Nalbach municipal council published a second resolution, according to which the economic and social life in Saarland would be endangered in the long term in the event of a flood. The communities of Riegelsberg and Schwalbach followed Nalbach.

In April 2016, the RAG applied for partial flooding of the Reden and Duhamel pits, initially at −320 m above sea level. For this, the pumps should be parked in these pits. The pit water should rise gradually until it could ultimately be drained into the Saar. In the following May, the municipality of Nalbach brought an action at the Saarlouis administrative court "against the approval of the special operating plan for the rise of pit water in the Saar mine, Duhamel operating area, up to the level of the 14th level, by the Saarbrücken mining authority".

At the end of the 15th legislative period of the Saarland state parliament, the investigation committee into the mine flooding was ended. His findings were essentially:

  • The flooding of the Saar mine at –400 meters above sea level was approved by the then Minister of Economics Maas - despite the rejection by the Environment Agency. Since the long-term RAG plan for complete flooding was known at the time, this permit was “the first step in the implementation of the mine water management concept, which provides for a complete increase in mine water. From the point of view of the state parliament, approval of this step would have required a final operating plan and a plan approval procedure with an environmental impact assessment. "
  • The contamination of the pits was also analyzed. It turned out that when the cavities were filled with the toxic fillers, a complete flooding was never assumed. PCB and other toxins of unknown extent, which were not taken into account when assessing a rise in mine water, make things more difficult.
  • According to the then Prime Minister Peter Müller before the committee, the content of the inheritance contract concluded with RAG in 2007 was that pumping is done forever in order to exclude the risk of drinking water pollution. "The optimization obligation, which the group is now referring to in order to justify its plans for complete flooding, related exclusively to the handling of the foundation's assets, not to a possible rise in pit water."
  • The expert Harald Friedrich also called for compliance with the perpetual contract, especially with regard to drinking water.

In conclusion, the state parliament of Saarland asked the state government:

  • "The inheritance contract with perpetual pumping of the pit water to protect the Saarland drinking water was to exist, ie the plans of the RAG AG to completely increase the pit water already now clearly to be rejected,
  • to revoke the permit to increase pit water in the Saar mine from –1450 meters above sea level to –400 meters above sea level and to include this partial flooding in the approval process for the increase to –320 meters above sea level,
  • Obtaining independent expertise in the approval process on all possible risks of a rise in pit water,
  • ensure before any approval that the presumption of mining damage also applies to damage caused by a rise in pit water, ie for all citizens living in communities affected by the rise in water, as well as for all possible damage caused by a rise in pit water. "

In January 2017, the feared impairment of the water-bearing layers by the pit water flooding was examined in more detail. Experts from the Saarland Environment Ministry considered the expected salt concentration, along with the iron content in the pit water, to be a greater risk than the PCB. The salts wash themselves out of the rock. The experts assumed that the mine flooding would reduce the concentration of pollutants anyway if the increased liquid was channeled into the Saar in Ensdorf as planned. The RAG also feared that PCB cleaning of the mine water would hardly be possible, and if so, it would be too costly. The removal of the salts was judged to be even more problematic, because the portions that did not flow into the Saar would threaten the groundwater.

In July 2017, Jürgen Wagner, operator of GGF GRUNDWASSER- UND GEO-FORSCHUNG GMBH, published the “Expert hydrogeological assessment of the rise in pit water in underground cavities caused by mining after cessation of coal mining in Saar carbon”, which was requested by the Upper Mining Office of Saarland.

Jürgen Wagner points out that this report also deals with other risks beyond - as required - possible impairment of drinking water. The main view was as follows:

  • With permanent mine water management, disadvantages would not necessarily be completely avoided, those with the planned increase of the mine water level to −320 m above sea level. could occur:
  • Vibrations: In the case of mine water management, these would occur less often, but they would be stronger due to the friction. On the other hand, with mine flooding, several vibrations would occur in the initial phase, which, however, are hardly noticeable. In addition, the CO 2 emissions are many times higher when pumping out forever.
  • The upper, used groundwater is not affected by the lower groundwater, so it cannot be impaired.
  • There may be a few limited rises in groundwater. It does not affect the production of drinking water. Cross faults through the main southern fault are difficult to predict. Continuous monitoring should therefore take place here, especially because of the wells in the Scheidtertal .
  • A high pressure dam has been built between Luisenthal and Geislautern at a depth of approx. 1000 m. Over time, the material tires and fine cracks can form. Ev. a moderate flood would ease the tension somewhat.
  • Unmounted boreholes for drinking water production are not affected by flood-induced vibrations.
  • Penetration of the carbon with water can cause moderate uplift on the order of a few centimeters.
  • A Göttelborn shaft would be ideal for installing permanent monitoring.
  • The concentration of salts in mine water is negligible - in contrast to stationary groundwater in the Carboniferous Mountains, where the salt had more time to accumulate. The PCB exposure will no longer be significant.
  • After detailed analyzes of hydrochemical mine water data, it is found that for most of the pits no reliable information can be given, so that the tests should be continued. The informative value should not be overestimated.
  • Above all, the salt loads should be defused.

In August 2017, the RAG submitted the "application to raise and discharge mine water at the Duhamel site in the Saar as a result of the mine water level rising to –320 m above sea level in the water provinces of Reden and Duhamel". Objections to this application could be made to the Oberbergamt des Saarlandes until January 15, 2018. Around 7,000 Saarlanders voiced their objection.

Then in January, at the instigation of the Mayor of Illingen , Armin König, a people's initiative of the Saarland with the title "Water is life - protect Saarheimat - stop mine flooding", prompted the state government of Saarland to deal with the subject of mine flooding.

During this time there was a hearing in the Saarland state parliament on the matter of mine flooding. A total of 24 municipalities and cities were represented. Of these, 22 clearly rejected the RAG's plan to flood to –320 m because of serious concerns. Two were undecided because there were different requirements.

In March 2018 it became known that the PCB load in some pits was 15 to 20 times higher than the tolerated values ​​of the environmental quality standard of 20 µg / l. According to the Ministry of the Environment, however, the treatment of the mine water should also be ordered in mid-2021 at the same time as the decision to discharge the pit water.

At the same time, the doctor from Quierschieder, Karl Michael Müller, reported serious concerns about the increased release of radioactive radon induced by the movement of the earth caused by flooding. The doctor had come across noticeably high lung cancer rates in old mining communities through the analysis of the Saarland cancer registry .

At the beginning of April 2018, the ProH2O Saar association was launched with the aim of protecting the surface waters of the Saarland and the groundwater and drinking water. Well-known founding members are Armin König, Barbara Meyer-Gluche, deputy state chairman of the Greens, and Hubert Ulrich, former state chairman of the Greens and ex-Member of the Bundestag.

On April 25, 2018, the application of the municipality of Nalbach for the non-approval of the special operating plan for the mine flooding at −400 m above sea level in 2013 was granted. A few weeks later, RAG and the Saarbrücken Mining Authority appealed against this decision.

Individual evidence

  1. ↑ [1] FragDenStaat. Last accessed on August 13, 2018
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  3. ^ [3] parliamentary group page of the Greens in Saarland. Last accessed on August 13, 2018
  4. ^ [4] parliamentary group page of the Greens in Saarland. Last accessed on August 13, 2018
  5. ^ [5] Saarbrücker Zeitung. Last accessed on August 13, 2018
  6. ↑ [6] Mining. Our Heritage. Side of the RAG. Last accessed on August 13, 2018
  7. ^ [7] Plenary minutes of the Saarland Landtag. Interview with Minister of Economic Affairs Rehlinger. Last accessed on August 13, 2018
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  9. ↑ [9] DER SPIEGEL 3/2015. Mining: poison in the shaft. Last accessed on August 13, 2018
  10. ↑ [10] State Parliament Protocol of the Saarland, p. 2061. Last accessed on August 13, 2018
  11. ^ [11] Printed matter of the Saarland Landtag. Last accessed on August 13, 2018
  12. ^ [12] Resolution of the Nalbach municipal council on the subject of perpetual costs and burdens in mining September 26, 2014. Last accessed on August 13, 2018
  13. ^ [13] Saarbrücker Zeitung. Last accessed on August 13, 2018
  14. ^ [14] page of the Saarland. Last accessed on August 13, 2018
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  16. ^ [16] Landtag des Saarlandes, printed matter 15/2110. Last accessed on August 13, 2018
  17. ^ [17] by Johannes Schleuning, Saarbrücker Zeitung. Last accessed on August 13, 2018
  18. ^ [18] EIA portal. Last accessed on August 13, 2018
  19. ^ [19] page of the Saarland. Last accessed on August 13, 2018
  20. ↑ [20] More democracy. last accessed on August 13, 2018
  21. ^ [21] page of the Saarland Landtag. Last accessed on August 13, 2018
  22. ↑ [22] by Ute Kirch, Saarbrücker Zeitung. Retrieved May 3, 2018
  23. ^ [23] Regional Association of Mining Affected Saar. Last accessed on August 13, 2018
  24. ↑ [24] Homepage of ProH2O. Last accessed on August 13, 2018
  25. ^ [25] Saarland, state law. Last accessed on August 13, 2018
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