RAG Aktiengesellschaft

It’s been two years since the last mines in North Rhine-Westphalia have been closed. On 21st December 2018 RAG miner handed over the last coal from the Prosper-Haniel mine in Bottrop/Germany, to Federal President Frank-Walter Steinmeier. Today RAG Aktiengesellschaft, Essen/Germany, has met all conditions to finally bid farewell to the underground world (Figure 1). “All of this in difficult times – and accident-free”, says CEO of RAG, Peter Schrimpf, praising his team. And the company is satisfied with the performances in 2020.

Also for the two mines in Ibbenbüren and Bottrop, which received assistance until most recently, the irrevocable farewell from the mine is now approaching, around two years after the shutdown of production, with the final deactivation of the pumps. While in Ibbenbüren the closure plan for leaving the rest of the mine was already approved in April, the mining authorities also issued this last approval in November for the Prosper-Haniel mine in Bottrop. With the approval for the closure plan procedures of the former Lohberg mine expected at the beginning of the year, RAG will come another step closer to the complete mining withdrawal and thus the implementation of the mine water concept in the Ruhr area because the site in Dinslaken is absolutely crucial in the RAG’s concept. “With this approval the mine water there can rise to a level of -630 m. This, in turn, is the prerequisite for enabling the mine water to spill over from Prosper-Haniel to Lohberg and no longer having to be fed into the Emscher river”, explains Schrimpf. In doing so, an important step is taken to completely free the Emscher of mine water by the end of 2021. The Emscher rebuild generation project can also be completed.

Apart from the mining approvals, the water permits for the raising and subsequent introduction of mine water into the receiving waters are now also entering a “stressful phase”. The mine water concept for the Ruhr area provides that in future mine water still only be raised from great depths at six locations with large submersible pumps and fed into the Ruhr, Lippe and primarily into the Rhine. In Ibbenbüren the mine water should go into the Aa via a mine water channel still to be built. Schrimpf: “We will create these processes openly and transparently. In the end it is about relieving as many river kilometres as possible of mine water and thus making a natural development of the waters possible.” The CEO of RAG attaches huge importance to the fact that the company is also available as a contact partner to citizens in the former mining regions even after the end of the coal mining sector. Schrimpf: “We’re here and will remain so. We will keep our word and tackle the impacts of mining in a responsible manner.”

To this end, RAG has restructured itself. There are currently just under 1,240 employees at RAG. In 2007, when the political decision was made to end the coal mining sector, the number of employees was 34,000. Almost 33,000 employees were laid off in a socially responsible manner. All those who were unable to transition into early retirement were offered new alternative jobs repeatedly. Around 160 former miners rejected all offers and filed a suit against RAG after compulsory redundancies. Schrimpf: “The behaviour of the colleagues really affected me personally. It shows a lack of solidarity. I have no time or sympathy. We will examine all available means of legal redress!”

The realignment of RAG also meant that the group had to part with business activities, e. g., from RAG Mining Solutions at the end of 2020. Since 2009 the company has marketed RAG mining equipment that is no longer required worldwide. Over 70 M € were generated in total. Schrimpf: “This was a further illustration of the excellent reputation German mining know-how and equipment enjoyed on an international level.”

On 31st December 2020 the former marketer of domestic coal and at one time the biggest German coal importer, RAG Verkauf, also ceased operation. For almost seven decades the company made a significant contribution to energy security in Germany (Figure 2). “RAG Verkauf always played a key role for the RAG Group”, says the CEO of RAG. “If RAG Verkauf was not able to market our coal, then the entire phase-out process of the German coal mining sector would not have been possible in a socially responsible manner. Because the necessary public funding was not available for the extracted, but for the sold tonnes of coal.” Since the middle of the 1990s, RAG Verkauf has also marketed international coal in addition to German coal and became an important coal importer, in 1998 it became Germany’s biggest coal importer.

The organisational optimisation of the property-related tasks is also making good progress. All activities, which are assigned to post-mining, such as the renovation of former mine areas or the cleaning of groundwater at former sites of coking plants, should be processed by RAG directly in the future. However, after the reorganisation the land development urgently required for new industrial locations in the former mining regions on the Ruhr, in Ibbenbüren and in Saarland remains a core activity of RAG Montan Immobilien. Schrimpf: “It makes a significant contribution to the structural change.”

At RAG the year 2020 was also characterised by corona. Schrimpf: “The pandemic showed us how vulnerable and fragile people, but also economic processes are. We were once again reminded of how important it is to support each other. Together we embraced the challenges and maintained the necessary business processes and at the same time were able to protect our staff.” (RAG/Si.)

Our underground is on the move. However, the shocks are often so small and spatially restricted that they are only detectable for very sensitive sensors. Even where mining was once conducted and people interfered with the natural geology and deposits, it may subsequently cause microseismic shocks. Paloma Primo, scientist at the Research Center of Post-Mining (FZN) at the TH Georg Agricola University (THGA), Bochum/Germany, pursues these mini-movements. In the new research project “PostMinQuake”, the expert examines how they occur exactly, identifies particularly endangered structures and develops a long-term risk management system for affected regions (Figure 1). To this end, she works closely with many European partners. Because also in the Czech Republic, Poland and France the post-mining period should not become a “nail-biting affair”. “The joint project is just as complex as the circumstances underground”, says Primo. “Our investigations go beyond the simple connections between seismicity and the geological activities in the decommissioned coal mines partly filled with water.”

Experts from various disciplines are working together in the project, including surveyors, geotechnical engineers or hydro-logists. Together they monitor the geological dynamics in the respective test areas, which have been changed by coal mining – in Germany this is mainly the Ruhr area, the Ibbenbüren and Aachen mining districts. “In these areas we document microseismic activities underground roughly once a week. There are also records from the past, which we analyse and put into context.” Primo obtains her data from the Geological Survey NRW, RAG Aktiengesellschaft, the Institute for Geosciences and Natural Resources (BGR), as well as seismological stations at the Ruhr-University Bochum (RUB). “At these stations we can determine time, size, place and depth of the event.”

The experts are pursuing an important common objective, explains Primo: “With our research we want to guarantee long-term safety, create transparency and inform the public. Because every municipality and every former mine operator should have sound knowledge of the processes that take place underground. When it comes to the topic of ground movements there are many fears and misunderstandings about what microseismic events are and the effects they can have.” Therefore, the main objective of the project is to gain a better understanding of the mechanisms of microseismic events after mining and create plans for the long-term monitoring of the soil after mining.

What external factors cause the micro-shocks? What factors can be used to realistically simulate the impacts on the PC? And how can satellite images help to properly interpret the data acquired from underground? “We’re talking here about vast amounts of data, which first of all we have to standardise in order to make it comparable and then be able to evaluate it using the latest methods”, says Primo. Over the next three years the project team will develop a reference database from the findings for European areas after mining. The research should also help to develop new monitoring strategies and interpretation methods for areas with increased risk of earthquakes. The project is part of the EU-financed Research Fund for Coal and Steel (RFCS). (THGA/Si.)

Alfons von Bronk, former Member of the Executive Board of Bergbau AG Lower Rhine, died on 2nd December 2020 at the age of 91 (Figure 1). “We have lost an exceptional person, to whom we owe a great deal. We will cherish his memory”, said Peter Schrimpf, CEO of RAG Aktiengesellschaft, Essen/Germany.

Von Bronk dedicated his entire career to coal mining. After posts in the underground operation of the König Ludwig 1/2 mine and as department manager for personnel/workers’ rights, in 1968 he became Manager of Human Resources of Ruhrkohle AG. In 1986 von Bronk was appointed to the Executive Board of Bergbau AG Lower Rhine. In a period marked by changes for the entire indigenous coal mining sector, he championed the company’s interests and concerns of staff demonstrating exceptional commitment and profound expertise. (RAG/Si.)

For almost seven decades long RAG Verkauf GmbH, Herne/Germany, made a significant contribution towards energy security in Germany (Figure 1). A success story whose last chapter comes to an end at the turn of the year. On 31st December 2020 – a good two years after the closure of the last two RAG mines – the former marketer of domestic coal and at one time Germany’s largest coal importer ceases its activities – but not without paving the way for the future for the staff, as well as individual business and product areas.

“RAG Verkauf has always played a decisive role for the RAG Group”, says Michael Kalthoff, RAG Chief Financial Officer and Chairman of the Advisory Board of RAG Verkauf. Thanks to detailed market knowledge and very good customer contacts, the sales specialists always managed to reliably sell the extraction of the local mines, even in difficult times. An extraordinary achievement, which was also necessary in order to make possible the entire phase-out process of the German coal mining sector in a socially acceptable manner. Because the necessary public funding was not available for the extracted, but for the sold tonnes of coal. According to Kalthoff, the efforts of all staff of RAG Verkauf therefore deserve the special appreciation and recognition of the Group’s entire workforce.

Despite these successes and a successful restructuring and development process, it was still unavoidable to cease the business operations of RAG Verkauf at the end of the year. Because without the domestic coal mining sector, RAG is simply no longer the so-called “Best Owner” in the post-mining era. Kalthoff is very pleased that it managed to close the company without any upheavals in a joint effort with the social partner.

RAG Verkauf employed more than 200 staff at its peak; in November 2020 this figure was still 16. The funds for the socially acceptable reduction of staff essentially covered transferring people from one job to another through the sale of entire business units including job guarantee for the RAG Verkauf staff, as well as semi-retirement models. “My heartfelt thanks to all involved for the successful realisation”, says Kalthoff. “And in particular to our social partner, who was always by our side during the entire time.”

The Steelworks Agreement concluded in 1968 and extended in 1985 and the Century Contract concluded in 1977 with its supplementary agreements between the mining and electricity industry were the basis for the supplies of German coal until into the 1990s (Figure 2).

“Since 1996 the sale of German coal has been in competition with the global market price. We are proud that RAG Verkauf sold over 0.6 bn t of coal and coke since then”, says Manfred Müller, Chairman of the Managing Board. “Over all these years the objectives of RAG Verkauf were able to be achieved thanks to the high identification and motivation of our staff.”

Since the company’s foundation in 1953, at that time it was called Präsident Ruhrkohlen Verkaufsgesellschaft mbH, the company has pursued a major core business: the marketing of German coal. Supplies of fine coal, lump coal and low-grade coal to the power industry represented the largest business area. Apart from large energy supply companies, other customers included municipal utilities and municipal providers. Through wholesale channels in the heating market sized anthracite also went to small consumers such as nurseries and garden centres who do not convert it into electricity or also as domestic fuel to public buildings and private households.

The large customers of the iron and steel producing industry used coking coal for their coking plants, as well as coke and pulverised coal injection for direct use in their furnaces. RAG Verkauf was also responsible for the sale of foundry coke, crushed coke and coke breeze. There was also products on the “white side” of the coking plants, mainly gas and coal derivatives such as tar and ammonia, which are used in the chemical industry as a raw material for numerous products – from toothpaste to plastics through to fertilisers.

Other business activities were added over the years, such as the marketing of tailings, which arose with the coal production, and the material flow management for the resource-friendly treatment and recycling of various materials. This also includes the cost-optimised and on-time secure backfilling of the RAG shafts no longer in use, which is a basic prerequisite for the release of the mine areas from the mining authority and thus also for the establishment of companies and jobs.

Since the middle of the 1990s, RAG Verkauf has also marketed international coal in addition to German coal and in 1998 became Germany’s biggest coal importer. The company purchased the import coking coal required for the Prosper coke plant directly from producers in Australia, the USA and Canada. The sale of the coke plant to ArcelorMittal Bremen in 2011, in which RAG Verkauf played a role in the negotiations, did not change anything in this regard.

The business also changed with the end of the German coal mining sector. The direct marketing of coal and coke is completed. In order to give the “International coal and coke trade” business unit prospects for the future, RAG Verkauf sold it in August 2018 to Xcoal Energy & Resources Germany GmbH with its registered office in Essen. By the end of 2020, RAG Verkauf secured the commercial winding-up of German coal production and is further developing the material flow management business field, including the shaft backfilling. From 2021 this business unit will be continued under the umbrella of RAG Montan Immobilien GmbH. (RAG/Si)

On 30th September 2020, RAG Aktiengesellschaft, Essen/Germany, submitted the planning notification for the drainage and discharge of mine water in the Ruhr at the three central water pumping sites Robert Müser, Friedlicher Nachbar and Heinrich (Figure 1) to the Mining Authorities of the State of North Rhine-Westphalia.

After the planning notification for the Haus Aden site and thus for the future discharge to the Lippe district was already submitted in the first quarter of this year, the RAG is also seeking a water permit in the Ruhr. In addition, the company is also planning the start of the approval process for the central water pumping site Lohberg this year.

Along the Ruhr the mine water is drained and discharged at the three sites Robert Müser and Friedlicher Nachbar in Bochum, as well as Heinrich in Essen. Mine water which is only slightly mineralised has already been discharged at the discharge points under view for several decades. The amount of the mine water to be discharged is not changing; it will remain at around 25 M m³/a altogether. The company is obtaining authorisation for instead of the previous 60 only 37 M m³ in order to be able to continue to discharge mine water in the case of deviations, such as extreme rainfall.

“The special feature of the water discharge consent for the Ruhr is that we are considering all three sites in one process”, states Project Coordinator Ralf Tinnefeld from the Permit Management Department (V-GM) on the special features of the procedure. This allows a holistic view of the objects of protection to be examined in the environmental impact assessment.

After a review of the planning notification the district government will send it to other public interest bodies such as authorities, associations and municipalities and invite them to the scoping meeting. At this meeting, the content and scope of the documents submitted by RAG in the water law procedure requiring an EIA will be discussed.

Even though the sites are being considered in one process, the application and approval are effected on a local level. “This is important as water rights always only have a limited term and can be cancelled and adapted at any time”, explains Thomas Brambrink, Department Manager for Water Discharge Consent/Monitoring at V-GM. “If this is the case at one site, a location-specific adaptation can be implemented without having to reopen the entire procedure.”

The water law approval procedure for the Ruhr is the next important element in the optimisation of mine water management of the RAG. (RAG/Si.)

RAG Aktiengesellschaft, Essen/Germany, started to digitise abandoned surface openings, shafts and mining galleries of the coal mining sector via the Sigfox-0G network. There are around 60,000 in North Rhine-Westphalia alone. The aim of this IoT connection is the continuous monitoring of changes in real time in order to increase protection against sinkholes and reduce the effort of on-site inspections. The Sigfox–0G-based mining shaft monitoring system, which is also used for long-term documentation, has been designed by the Research Center of Post-Mining (FZN) and the Electrical Engineering/Information Technology and Industrial Engineering research sector of the TH Georg Agricola University (THGA) in Bochum/Germany and developed to series production in cooperation with the RAG (Figure 1).

The 0G-based remote monitoring system which is operated by a solar generator comprises pull-wire switches and a microcontroller with radio transceiver, which transfers the data via Sigfox-0G networks to a monitoring cloud. The sensors monitor, e. g., the vertical movement of the filling column of an old mine shaft. The data collected via Sigfox-0G network can be shown in the cloud for monitoring purposes and in the event of an alarm can be automatically sent to a predefined message chain by SMS and e-mail.

“It is necessary to constantly monitor the over 5,200 km² hard coal easements in our area of responsibility which have around 7,200 former surface openings because sinkholes are possible at any time in a section of around 100 km². Therefore, around 6,000 inspections are carried out every year in order to be able to take preventative action in good time. To minimise these on-site inspections and for real-time monitoring of any changes, selected surface openings are now also constantly monitored via a Sigfox-0G network connection”, says Frank Wollnik from the Site and Geo Services Division of RAG.

“The Sigfox-0G solution for shaft monitoring is an element of the so-called Mineberry system, which works completely independently and is solar-operated and is suitable for almost every type of old mining objects thanks to the modular structure. In order to implement the cloud connection of our remote monitoring solution in a manner that is cost-efficient, long-lasting and maintenance-free, we connected proven sensor technology to the innovative Sigfox-0G network. And as it can be used worldwide without any roaming charges, our solution can also be used worldwide”, explains Prof. Bernd vom Berg, Head of the Laboratory for Electrical Measurement and the Laboratory for Microprocessor Technology at the THGA.

“The RAG monitoring system is an excellent example of the remote monitoring of things and states, which up to now could not always be given special attention because it was too expensive or too energy-hungry to record all this data in real time. However, with Sigfox 0G real-time monitoring of even the simplest objects and states is possible. In the case of mining, it is easy to imagine that there are many control points worldwide, which can be monitored via a Sigfox-0G network. Especially because after the fossil-fuel phase-out no more money is earned, cost-efficient and low-maintenance data communication channels like Sigfox-0G offers are particularly important”, explains Stéphane Pâris, Technical and Network Director at Sigfox Germany.

The 0G controller is installed aboveground outside the possible Ex zone for the remote monitoring system for surface opening monitoring, whereas the Ex-protected sensors are installed in the shaft. As radio signals can be transmitted via the Sigfox-0G network across many kilometres, their use is also possible in areas with a poor mobile phone connection. The controllers can also be operated for many years without changing the batteries thanks to the battery-saving radio technology. Installations in the equally radio-critical underground environment can be found in the water supply network of the city of Antwerp. However, prerequisites for extensive underground installations are repeaters, which must be positioned every 3 to 5 km. (THGA/Si.)

RAG Aktiengesellschaft, Essen/Germany, is putting its spoil tips in new hands: The Ruhr Regional Association (Regionalverband Ruhr, RVR) is taking over 20 redeveloped mining sites with a total surface area of 1,149 ha (Figure 1). These are primarily intended to be developed into natural sites and activity areas.

“The mountains of the Ruhr metropolitan area are more than viewpoints. As landmarks, they are points of reference in the urban landscape and represent a unique feature of this region with their ever-changing backdrop. The acquisition of further spoil tips offers us, as the largest spoil tip owner in the Ruhr region, the opportunity to significantly help shape the geographical development of our region,” explains RVR Regional Director Karola Geiß-Netthöfel. RAG is keeping its promise to make post-mining sustainable for the people in the mining regions, according to Peter Schrimpf, Chairman of the Executive Board of RAG: “Not only can our areas help with creating new jobs; they can also make the district more attractive. Needless to say, this also includes our spoil tips. However, we are unable to guarantee public use permanently. The RVR is clearly better suited to this.”

“We want to incorporate the spoil tips into the green infrastructure of the Ruhr metropolitan area and open them up to the people of the Ruhr region as well as tourists. They are not just decorative structures but rather important components in the creation of a climate-friendly region,” adds RVR representative Nina Frense. Some of the newly acquired spoil tips are already accessible to the public and are being used for leisure and tourism purposes, for local recreation or for energy production – in 2021, this already applies to nine spoil tips with a surface area of 380 ha. These are the spoil tips of Lohberg North (Dinslaken), Scholver Feld (Gelsenkirchen), Rungenberg (Gelsenkirchen), Mottbruch (Gladbeck), Graf Moltke 2 (Gladbeck), Elsa-Brändström-Straße (Lünen/Dortmund), Blumenthal 8 (Oer-Erkenschwick), Humbert (Hamm) and Groppenbruch (Dortmund).

Other spoil tips are still under mining authority supervision and will gradually be made accessible to people in the Ruhr region. The stages of the closure plan will be successively completed by RAG subsidiary RAG Montan Immobilien GmbH by 2035. Over the course of the next 15 years, the spoil tips Haniel (Bottrop), Canal Belt – Haus Aden (Bergkamen), Brinkfortsheide (Marl), Lohberg North extension (Hünxe), Sundern (Hamm), Radbod (Hamm), Scholven (Gelsenkirchen), Kohlenhuck (Moers), Graf Moltke 1 (Gladbeck), Wehofen East (Dinslaken/Duisburg) and Rossenray (Kamp-Lintfort) will be gradually handed over to the RVR.

“By handing the spoil tips over to the RVR, RAG will save on maintenance costs. In this way, we will be able to contribute some of these savings to the RVR’s maintenance costs for a period of 20 years. We are therefore playing an important part in the transformation of the Ruhr region and in the future public use of spoil tips,” states Michael Kalthoff, CFO at RAG.

The operating costs for the upkeep of the landscape and trail system amount to around 1.4 M € per year for the 20 spoil tips. RAG will contribute half of the maintenance expenses. The RVR has already commissioned external planning offices to look into if and how the reclaimed mining sites can be used for tourism, leisure and recreation. The result of the utilisation concept is that nine spoil tips with a total surface area of 742 ha are suitable for developing tourist facilities because of their site qualities.

The nine spoil tips that are of special interest for tourism purposes include Kohlenhuck, Lohberg North, Haniel, Mott-bruch, Scholven, Rungenberg, Brinkforts-heide, Haus Aden 2 and Humbert. Haus Aden 2, Lohberg North, Mottbruch and Brinkfortsheide are also being considered as potential sites for the International Garden Festival (IGA Ruhr metropolitan area 2027). The other eleven spoil tips will add to the green leisure and recreation infrastructure of the Ruhr metropolitan area and enhance it from an ecological point of view. Energy production systems have already been installed at six spoil tips, while other spoil tips are being considered as potential sites for wind turbines or solar plants.

Consultants involved in the utilisation concept estimated the investment costs for qualifying the spoil tips to amount to around 50.4 M €. The RVR will attempt to secure funding for this.

The RVR is the owner of 37 spoil tips to date. Many of them have already been specifically developed so that they remain visible landmarks. Works of art have turned them into symbols of the new Ruhr region. At the same time, they have been transformed into attractive areas for tourism, recreation, leisure and sport. (RAG/Si.)

RAG Aktiengesellschaft, Essen/Germany, tested methods for further reducing PCB in pit water at pilot facility level in Bergkamen and Ibbenbüren. The initial results from this series of tests are now available. The investigation into the PCB content takes place at the margin of detectability in the trace substance range. The analytical process being used here for the first time needs further development. At the same time, project manager Christoph Schabronath emphasises that: “The environmental quality standard for PCB in water is being adhered to at both the Haus Aden and Ibbenbüren sites.”

RAG broke new ground with this project and exceeded the legal requirements. Both the systems engineering and the analysis in the trace substance area were challenging. The task was to filter the smallest traces of PCB out of a large volume of pit water and to analyse it.

In North Rhine-Westphalia, RAG operated a pilot facility on container scale for removing PCB from pit water at the Haus Aden site, followed by Ibbenbüren (Figure 1). Further developed technologies and operating methods from drinking water preparation were used, i. e. single- and multi-layer filters made from quartz sand and anthracite coal in the pit water side stream.

Schabronath explains: “The pilot facility ran smoothly at both sites. However, the examination of the PCB content took place at the margin of detectability in the trace substance range.” Reliably determining such small traces of a substance and assessing the results is extremely challenging, and requires experience and a procedure adapted to the specific case at hand.

Due to the low concentration of PCB in the pit water, the results were unclear and it was not possible to eliminate uncertainty in the analysis. With such minimal traces, parallel investigations into the background presence of PCB in air and water are necessary.

At the end of 2019, an expert group consisting of ministries, authorities, surveyors and scientists met to assess these results. This group of experts also sees a need for further research. RAG has committed to further developing the analytical method within the framework of a doctorate in cooperation with the TH Georg Agricola University (THGA) in Bochum. (RAG/Si.)

The Haus Aden 2 shaft from RAG Aktien-gesellschaft, Essen/Germany, in Bergkamen is currently being filled. In 2023, submersible pumps are to pump mine water at depth through cladding tubes. The filling work will be completed by the end of the year. RAG has submitted the planning notification to North Rhine-Westphalia’s mining authority in order to raise and discharge mine water from the Haus Aden site into the Lippe river. RAG has provided an initial overview of the project in this planning notification, which makes the procedure transparent right from the start.

After coal mining has ended, the long-term optimisation of mine water drainage is a central element of the perpetual obligations. The mine water plan for the Ruhr region envisages that, in the future, the mine water will only be raised at six central water drainage sites. Haus Aden in Bergkamen is one of these future central water drainage sites.

No mine water is currently being raised at Haus Aden. The site is currently being converted into a well drainage system (Figure 1). For this purpose, Thyssen Schachtbau, Mülheim an der Ruhr/Germany, is building three cladding tubes in the shaft. This happens step by step. First of all, the tubes are constructed section by section and then the corresponding shaft section is filled with concrete. Work started at the end of September 2019. At present, approximately 120 m of concrete has been poured – a total of around 5,000 m³ of concrete. The remaining 660 m should be completely filled by the end of the year and the pumps should be operational by the end of 2023.

RAG expressly supports the Water City project in its planning work. As a result, a new functional building based on a harmonious and coordinated overall plan is also to be jointly turned into an architectural landmark. RAG is planning a power house at the site, which will contain a well system with lifting equipment for the pumps and pipelines that, in the future, will regulate the mine water level in the eastern Ruhr region. Preserving the shaft frame is not compatible with these plans. The power house will not fit under the existing construction. Instead, it is to be built on the dismantled shaft frame foundation in order to transfer the huge total load of the lifting equipment and the three suspended pipelines, each weighing 500 t, into the ground. This is the latest point at which the remaining steel construction’s statics can no longer be guaranteed.

In order to resume drainage after the target horizon has been reached, RAG requires a new permit relating to water laws in order to raise and discharge mine water into the Lippe river. The planning notification marks the start of the water law procedure, which also includes an Environmental Impact Assessment (EIA). This planning notification has meanwhile been sent by the mining authority to authorities, associations, communities and other public bodies. The mining authority will soon invite these recipients to a scoping meeting. At this meeting, the content and scope of the documents submitted by RAG in the water law procedure requiring an EIA will be discussed.

The water law procedure will also deal with the issue of removing traces of PCB present in mine water. To investigate the extent to which it is possible to separate these traces from the mine water, RAG already began operating container-scale pilot facilities at the Haus Aden and Ibbenbüren sites about a year and a half ago to filter out the smallest traces of PCB from a large quantity of mine water and examine them analytically. The pilot facility ran smoothly at both sites. At the end of 2019, the results were evaluated by an expert group consisting of ministries, authorities, RAG, IWW, surveyors and scientists. Since this group of experts also sees a need for further research – especially in the field of analytics – RAG has committed to further developing the analytical method within the framework of a doctorate in cooperation with the TH Georg Agricola University (THGA) based in Bochum/Germany. (RAG/Si.)

The long-term optimisation of mine water drainage is a central issue regarding which RAG Aktiengesellschaft, Essen/Germany, is facing up to its responsibility in the period after active coal mining has ended. The Ruhr region’s mine water plan envisages that mine water will only be raised at six central drainage sites. From 2030 onwards, the Lohberg site in Dinslaken will be the largest central water drainage system in North Rhine-Westphalia (Figure 1). Up to 33 M m³/a of water will be raised here and discharged directly into the Rhine river.

In an extensive feasibility study, RAG has demonstrated that raising mine water at the Lohberg site will, in all probability, be technically possible and that subsequent discharge into the Rhine river will be legally permissible. RAG’s mine water plan provides for various safety measures that are taken into account in the feasibility study. The feasibility study is a basic prerequisite for approving the outstanding colliery closure plans, in particular regarding the former Prosper-Haniel mine and withdrawing from the Zollverein, Amalie and Carolinenglück mine water drainage sites.

RAG’s mine water plan for the “water province” of Lohberg envisages discharging mine water directly into the Rhine river in the future. This means that the Emscher river will be completely cleared of mine water. This is a basic prerequisite for successfully completing the intergenerational Emscher conversion project. In this sense, the Lippe river will also be significantly relieved.

The plan also provides for a clear distance between the mine water and the groundwater resources used for drinking water production at all times and in the long term. This applies, in particular, to drinking water production from the Halterner Sande area, through which over 50 M m³/a of natural groundwater is currently extracted for drinking water supply. The mine water plan is thus primarily also a concept for drinking water protection. (RAG/Si.)