Energy

20 Years Wismut GmbH 20 Jahre Wismut GmbH Remediation for the Future

www.bmwi.de www.bmwi.de Text and editing Federal Ministry of Economics and Technology Dr J. Becker & Dr G. Ruhrmann, Partnerschaft, Erftstadt Wismut GmbH, Chemnitz

Design and production PRpetuum GmbH, Munich

Picture credits Wismut GmbH, cover photograph: New Ronneburg Landscape

Printed by Silber Druck oHG, Niestetal

Publisher The Federal Ministry of Economics and Federal Ministry of Economics Technology was awarded the audit and Technology (BMWi) berufundfamilie® for its family-friendly staff Public Relations Division/L2 policy. The certificate is conferred by the D-10115 Berlin, Germany berufundfamilie gGmbH, an initiative of the www.bmwi.de non-profit Hertie Foundation.

March 2011 Energy

20 Years Wismut GmbH Remediation for the Future 2

Table of contents Inhalt

Foreword ...... 3

1 Wismut uranium ore mining operations in Saxony and Thuringia ...... 4

2 Remediation goals and concepts ...... 10

3 Engineering services, licensing process, monitoring ...... 15

4 Remediation sites ...... 19

5 Stewardship sites ...... 53

6 Public relations ...... 55

7 Arts collection ...... 56

8 Documentation on Wismut corporate history ...... 57

9 Summary and outlook ...... 58 3

Foreword

Celebrating 20 years of Wismut GmbH means giving the company credit for 20 years of successful remedial action in Saxony and Thuringia, including the mitiga­ tion of environmental damage, the substantial reduc­ tion of environmental impacts, the creation of live­ able landscapes for the benefit of the people living in live-able former mining regions, and the creation of conditions and prospects for economic revival.

With German reunification in 1990, the Federal Republic of Germany has assumed the sole social and financial responsibility for the decommissioning and rehabilitation of immense legacies. By the end of 2010, the federal government had made available funds totalling some 5.4 billion euros to finance the remedial operations.

This brochure portrays the initial situation and the results achieved thus far in mine decommission­ ing and remediating former mining areas to prepare them for future reuse. In addition, it provides an over­ view of the tasks ahead. The presentation of this report is also a token of gratitude to the staff of Wismut GmbH and to everybody else involved in the Project for their outstanding achievements.

Federal Ministry of Economics and Technology 4

1 Wismut uranium ore mining operations in Saxony and Thuringia

The legacies left behind by uranium ore mining were GDR on August 22, 1953. This agreement was renewed generated by more than 40 years of mining and pro­ in 1962 and was extended in 1975. cessing of uranium ore in East Germany. As early as 1946, the then Sachsenerz Bergwerke AG started ura­ Annual uranium production peaked in 1967 with nium mining from abandoned mine dumps, adits, a rate of 7,100 tonnes. In 1990, production was still at and mine pits, under supervision of units of the Soviet some 3,000 tonnes of uranium. By the end of uranium military. To cover reparation claims, the mining com­ ore mining on December 31, 1990, Wismut mining panies operating in the Soviet occupation zone were units had produced a total of some 231,000 tonnes of transferred into Soviet ownership. Thus, the Soviet uranium, ranking the GDR according to latest find­ stock company Wismut was founded in 1947. The goal ings as the world’s fourth largest uranium producer of the undertaking was to provide uranium for the after the USSR, the United States, and Canada. nuclear armament programme of the Soviet Union. A large workforce, conscripted from across the Soviet Following German reunification, the Federal zone of occupation, was forced to work in the ura­ Republic of Germany and the Soviet Union signed a nium mines. Uranium mining and processing during transition agreement on October 9, 1990 under the that period was characterised by bad working condi­ provisions of which SDAG Wismut ceased its opera­ tions, complete disregard for nature and the envi- tion on January 1, 1991. This put an end to uranium ronment, as well as reckless encroachments on popu­ ore mining in Saxony and Thuringia. lation centres. Whole areas were confiscated and turned into prohibited zones: Wismut became a state In 1990, the environmental situation in the min­ within a state. ing districts was characterised by enormous environ­ mental degradation affecting a total surface area of In 1954 the German Democratic Republic (GDR) some 3,700 hectares, including radioactively contami­ got a share in what had been a purely Soviet stock nated mine dumps, tailings ponds, and plant areas company up to that time. The company was convert­ located within a densely populated region. Past min­ ed into a Soviet-German stock company SDAG Wismut, ing activities had marked the mine and mill sites of with both partners holding 50 per cent of the shares. Ronne­­burg, Seelingstädt, Crossen, Schlema, Pöhla, The basis for this change was an agreement conclud­ König­stein, and Dresden-Gittersee with their traces of ed between the governments of the USSR and the devas­tation. Uranium mining operations had released

Parking lot and pit shafts against a background of waste rock piles at Schlema (ca. 1965) 5

Schlema spa park with shade sail against the background of Hammerberghalde waste rock pile (2001) radio­active materials into the atmosphere, into soils, duction legacies were defined as and remain the and into the hydrosphere. More than 300 million company’s key mission and corporate purpose. The cubic metres of waste rock material had been brought Federal Republic of Germany is its only shareholder, to the surface and dumped in 48 waste rock piles. Pro­ represented by the Federal Ministry of Economics and cessing uranium ore into yellowcake had generated Technology. more than 160 million cubic metres of tailings sludges containing residual levels of uranium and other con­ Following the usual practice in countries with taminants. This situation made it imperative already planned economies, the SDAG Wismut had not set in 1990 to initiate immediate action to eliminate haz­ aside any financial reserves for future decommission­ ardous risks, to close mines and pits, and to clean up ing and rehabilitation work. As a consequence, the and rehabilitate production sites. federal government had to allocate sufficient funds for the Wismut GmbH company to fulfil its mission. The national Wismut GmbH – a federal responsibility The legal framework for the decommissioning and rehabilitation work is set forth in the Wismut Act Under the terms of German unification, ownership of as well as all other relevant regulations, laws and 50 per cent of the shareholdings of the binational ordinances contained in German mining and radia­ company SDAG Wismut passed to the Federal Republic tion protection legislation in particular as well as in of Germany. Under the terms of the German-Soviet German soil protection and water legislation. Fur­ governmental agreement of May 16, 1991, the Soviet thermore, under the provisions of the German unifi­ shareholdings were also transferred to the German cation treaty, two former GDR regulations containing side. As a consequence thereof, the Federal Republic specific provisions on the decommissioning of urani­ of Germany assumed responsibility for the company um mines (Nuclear Safety and Radiological Protection as a whole. On December 20, 1991, with the coming Ordinance and Mine Dump Ordinance) continue to into force of the Wismut Act of December 12, 1991, the be applied. Moreover, the German Commission on company SDAG Wismut was changed into Wismut Radiological Protection has issued a number of radio­ GmbH, a company under German corporate law. Site logical protection principles concerning the release decommissioning and rehabilitation of uranium pro­ of contaminated areas, waste rock piles, buildings, 6 1 Wismut uranium ore mining operations in Saxony and Thuringia

and materials originating from uranium ore mining. prehensive assessment of their ecological, economic These principles are taken into consideration when as well as social aspects. This optimisation process assessing the need to remediate areas and facilities. also comprised considerations regarding the long- term stability and follow-up costs of the different From mining to remediation company approaches. Trade-offs between the various interests were conducted in close cooperation with the rele­ A priority task to be addressed in the early 1990s was vant state supervisory authorities and through dia­ the restructuring of the company from a mining com­ logue with municipal and district representatives of pany oriented toward the maximum production of the affected areas. uranium under the conditions of a planned economy into a modern private sector remediation company. The decision-making process had to acknowl­ On January 1, 1992, the numerous affiliated mine sup­ edge that a good many of the remediation operations port activities of the SDAG Wismut were split from the were indeed intervention measures which have the newly founded Wismut GmbH and privatised during capacity to mitigate environmental damage but can­ the mid-1990s. not undo environmental impacts altogether. In the end, concepts were worked out through constructive When uranium mining was terminated at the cooperation with the regulatory bodies of the Free end of 1990, there were no ready concepts or plans States of Saxony and Thuringia which built a safe and available to initiate the pending remediation meas­ generally recognised basis for future remediation ures. For this reason, remedial concepts for all task planning by Wismut GmbH. First site-specific remedi­ complexes had to be developed at short notice. A pre­ al concepts were finalised by August 1991 and then requisite for the development of remedial concepts continuously updated in accordance with growing was the assessment of the existing environmental expertise and know-how. They provide the basis for impacts and the establishment of an environmental concrete design and planning of the various remedia­ database. The need for environmental restoration tion measures as well as for the annual work pro­ and the definition of concrete remediation goals grammes. All work projects are submitted by Wismut were derived from the analysis of these data. This GmbH to the competent authorities of the Free States meant in particular that the various options and alter­ of Saxony and Thuringia for approval and licensing. natives had to be submitted to a thorough and com­

Decommissioned Mine

Decommissioned Prosess Plant

Wismut Head Office

Wismut Sites 7

The multitude and diversity of tasks to be ad­ sented in compliance with the 1976 Co-determination dressed in developing remedial concepts required Act. Since 2009, the supervisory board has nine mem­ the pooling of international technical and scientific bers in accordance with the One-Third Employee expertise and the involvement of a great number of Representation Act. German and foreign experts. Today, Wismut GmbH comprises the head office, Organisation/corporate structure based in Chemnitz, and seven rehabilitation units in Saxony and Thuringia. The corporate structure has One of the priorities among the tasks to be addressed been continuously adapted to the progress in remedi­ following assumption of responsibility for the Wismut ation in a bid to conduct remedial processes in a cost- company by the federal government in 1990 was the effective manner. restructuring of the company from a mining compa­ ny oriented toward the production of uranium under Funding conditions of a planned economy into a modern pri­ vate sector remediation company. In the transition With German unification the federal government period leading to the founding of Wismut GmbH, the has not only assumed sole social responsibility for German side had already assumed managerial lead­ the remediation of the legacies left behind by urani­ ership as agreed during German-Soviet negotiations. um ore mining in Saxony and Thu­ringia but has also For that period, the Federal Ministry of Economics taken on sole responsibility for financing the enor­ and Technology had appointed an advisory board to mous tasks. Wismut GmbH is an institutional donee act as an interim supervisory board. Upon the found­ funded by the federal government. To complete the ing of Wismut GmbH, three executive officers and a environmental restoration programme, the federal supervisory board were appointed. Until 2009, the government has earmarked 7.1 billion euros, some shareholders and employees each had six representa­ 5.4 billion of which had been spent by the end of tives sitting on the supervisory board, equally repre­ 2010 − 2.9 billion in Thu­ringia and 2.5 billion in

Number of Personnel mill. euro 30,000 700 27,800

577 600 25,000

500 20,000 461

359 400 15,000 311 300 248 10,000 203 200 6,700 146 5,600 5,000 4,600 3,100 100 2,200 1,500 0 0 1991 1992 1993 1995 2000 2005 2010

SDAG Wismut Wismut GmbH Financing

Source: Wismut GmbH

Financing and workforce development 8 1 Wismut uranium ore mining operations in Saxony and Thuringia

Industrial zone established on former Paitzdorf plant area, Ronneburg Operations Office (2009)

Saxony. Financing needs are established on the basis is a remarkable achievement made possible by good of the company’s annual work plans, which are understanding among the parties involved, i. e. the adopted as part of the federal budget by the German Federal Ministry of Economics and Technology as parliament. owner, the supervisory board, management, staff, and the labour union. Workforce development The main goals set for workforce development – One of the major problems to be addressed during to ensure the completion of remedial tasks in a good the early years following the termination of uranium and workmanlike manner by experienced Wismut ore mining was to adapt and size the workforce to staff and to achieve socially acceptable workforce meet the challenge of the forthcoming remedial reduction – have been fulfilled. action. At the time when uranium ore mining and processing ceased, Wismut’s workforce totalled Managerial tasks funded by the federal budget almost 28,000 employees. Numerous jobs were lost encompass decommissioning and rehabilitation pro­ during the initial years. Setting up two employment jects, employment promotion schemes, redundancy promotion schemes made it possible to streamline programmes and other personnel policy regulations the production workforce in a socially acceptable for a socially acceptable staff reduction as well as manner. Close to 11,000 employees registered with extensive educational opportunities for more than those schemes and joined various employee develop­ 1,500 young people who have received training in a ment and job conversion training programmes. variety of trades with a promising future in the for­ mer mining regions. Following the spin-off of mine support and auxil­ iary units on January 1, 1992, Wismut GmbH had still Wismut as an economic factor some 6,700 employees on its payroll. In 2011 some 1,500 remain. That such drastic staff cuts could be car­ For the past 20 years, Wismut GmbH has been mak­ ried out in a socially acceptable manner using various ing a major contribution to shaping improved living tools (employment promotion schemes, semi-retire­ conditions and to the economic stabilisation of the ment, and miners’ insurance compensatory payments) former mining regions. Rehabilitation of areas is an 9

important prerequisite to attract investors and ensure ation of uranium mining legacies. In the course of the sustainable development. Achievements so far include­­ ongoing remedial process – including decommission­ the establishment of forest and grassland areas for ing, remediation and preparation for reuse – Wismut recreational use, the reactivation of tourism, the set­ staff have acquired vast scientific and technical know- tlement of new industrial plants as well as the instal­ how and developed state-of-the-art remedial technol­ lation of a solar park. By implementing this environ­ ogies of their own in dealing with radioactive mining mental restoration project, Wismut and the subcon­ legacies. Since the mid-1990s, demand for the compa­ tracted local firms make a major contribution to ny’s experience and the technical expertise has been em­­ploy­ment and job creation in the region. So far, growing from external, mainly international clients. Wismut GmbH has awarded third-party contracts Marketing of the know-how was initially assured by totalling some 1.9 billion euros, including ca. 1 billion the corporate unity Wismut-Consult and since 2002 is euros in Saxony and ca. 0.6 billion euros in Thuringia. performed by the wholly-owned subsidiary WISUTEC These contracts usually cover the purchase of materi­ Umwelttechnik GmbH, which was privatised in 2010. als and equipment; the supply of energy, raw materi­ als and fuels and the purchase of engineering and The Wismut environmental restoration project construction services. has emerged as a significant international reference project for the clean-up of radioactive legacies. Favourable urban development following com­ Wismut GmbH has presented its comprehensive prehensive rehabilitation of mining legacies is out­ expertise and experience at a multitude of seminars, standingly exemplified by the community of Bad congresses, and workshops at the national and inter­ Schlema in Saxony which has regained its former title national levels, and the company itself has also organ­ as a spa town. Successful reclamation of former min­ ised a number of international forums for exchang­ ing sites is also manifest in East Thuringia where ing experiences on major issues of mine rehabilita­ areas rehabilitated by Wismut GmbH were to a large tion. Prominent partners in these efforts included the extent incorporated into the BUGA 2007 national hor­ U.S. Department of Energy (DOE) as well as organisa­ ticultural exhibition as the “New Ronneburg tions and firms from Canada and Australia. These Landscape”. exchanges were subsequently joined by Eastern Euro­ pean and CIS countries which, like Wismut, were in International cooperation and the process of decommissioning their uranium indus­ exploitation of remedial know-how tries. This network of mine operators, remediation and expertise companies, regulators, and domain experts has estab­ lished itself as the “Uranium Mining and Milling From the outset of the remediation project, a priority Remediation Multilateral Exchange Group” (UMREG) was placed on making sure that the Wismut project and organises topical symposia at regular intervals. drew on and benefited from the international exper­ Since 2009, these meetings are held in Vienna under tise and experience that other countries – such as the the auspices of the International Atomic Energy United States and Canada – had gained in the remedi­ Agency (IAEA). 10

2 Remediation goals and concepts

Since 1990 Wismut GmbH is conducting the remedia­ mines. Shutting off the pumps which dewatered the tion of the legacies of uranium ore mining left behind mines during operation will allow natural inflow of in Saxony and Thuringia. This clean-up work is aimed groundwater into the mines. Prior to initiating the at removing the hazards generated by uranium ore flooding process, oils, greases, and chemicals will be mining and its legacies or at least diminishing such removed from the mines with a view to minimising risks to an acceptable residual level and at restoring subsequent contaminant release via the aquatic path­ an environment that is ecologically largely intact and way. In a next step, mine workings of low rock me­ fit for reuse in compliance with the provisions of the chanical stability – and in particular near-surface cav­ Federal Mining Act. This is an indispensable prerequi­ ities – will be backfilled with self-hardening material site for the economic revival of the regions affected by to prevent surface subsidence and ensuing mine Wismut mining operations. damage. Backfill materials consist of a mixture of sand, water, and cement or power plant fly ashes. In an initial phase, concepts had to be worked out Shafts and adit openings are safely sealed and for the remediation of the mining legacies. The con­ plugged with concrete. In the meantime, mine flood­ cept-building process had to identify solutions which ing at the Pöhla, Schlema-Alberoda, Dresden-Gitter­ were both ecologically effective and sustainable for see and Ronneburg sites is almost complete. Flooding the remediation of mines, waste rock piles, and tail­ of the Königstein mine is not yet terminated. ings management areas as well as for the treatment of contaminated waters generated during and past Mine dump remediation concepts remedial operations. What would happen to plant buildings, production facilities, and plant areas was Waste rock and overburden stockpiled in mine also up for decision. dumps of Wismut resulted from the development of the various ore deposits. Given their levels of natural­ Mine remediation concept ly occurring radionuclides, their resulting specific activity is basically within a range that requires reme­ The remediation concept for the mines at the Ronne­ diation for compliance with radiation protection leg­ burg, Schlema-Alberoda, Pöhla, Königstein, and islation. Moreover, the waste rock material contains Dresden-Gittersee sites calls for the flooding of the heavy metals which may be relatively easily mobilised

Beerwalde waste rock pile (2010) 11

such as e. g. iron, nickel, and copper, which have to be prevented to the extent possible from unrestricted access to groundwater and surface water. In addition, slopes of many waste rock piles were too steep, and there was a real risk of slope failure. Safe remediation of the waste rock piles is therefore required under Top soil mining, radiation protection and water legislation.

At Wismut waste rock pile remediation follows two different approaches: the concept of relocation whereby several waste rock piles are excavated and moved to a single location and the concept of remedi­ Moisture storage layer (mineral soil, 2 lifts) ation in situ whereby the waste rock piles are remedi­ ated in place. Which of the two concepts is followed in a given case is determined by site-specific condi­ tions, cost-benefit considerations, and public accept­ ance issues.

All but two smaller waste rock piles located to the Mine waste rock pile south of the motorway at the Ronneburg site were relocated into the worked-out Lichtenberg open pit mine, while the Drosen and Korbußen waste rock piles located to the north of the motorway were banked against the Beerwalde waste rock pile. At the Standard two layer mine dump covers exemplified on the case of majority of waste pile sites in Saxony relocation was the Schlema site not feasible for lack of space or economic considera­ tions. For this reason, these waste rock piles were In order to achieve the above mentioned goals, almost without exception remediated in situ. Mine Wismut has designed a number of site-specific cover dumps which contain waste rock and overburden options. Their topmost element is a topsoil layer fol­ materials suitable for capping purposes at tailings lowed by mineral soils acting as moisture storage management areas constitute an exceptional case as layer. Depending on conditions at the site, the cover they are either in part or entirely relocated for place­ may comprise an additional infiltration barrier made ment atop tailings management areas. of clayey material. Grass seeding follows immediately after completion of the cover. This primary seeding The basic remedial concept applicable to all serves as a protection against erosion and stabilises waste rock piles provides for enhancing long-term the newly established top soil layer. slope stability and covering the piles with mineral and vegetation supporting soils. The cover has a num­ Both landscape features newly constructed by the ber of functions to fulfil. It has to reduce infiltration of relocation of waste rock piles and piles remediated in precipitation into the waste rock pile body in order to situ have to be provided with farm roads and draining minimise the volume of contaminant-bearing seep­ ditches for collection and discharge of surface run- age waters. Furthermore, the cover shall prevent off. The concept for the reuse of reclaimed waste rock direct contact with the waste rock material and pile surfaces recommends the establishment of a for­ diminish the environmental impact of radioactive est and meadow landscape. The basic principle un­ releases from rock to a level within the natural back­ der­­­lying the landscaping of remediated waste rock ground range. Finally, the waste rock pile cover must piles provides for their contours and vegetation to support vegetation growth. blend in with the surrounding scenery.

12 2 Remediation goals and concepts

Tailings management facility The superimposed load of the interim cover squeezes remediation concept some of the pore water out of the fine-grained tail­ ings; the expelled pore water rises along the vertical Residues generated during the processing of urani­ drains into the interim cover from where it runs by um ores at Seelingstädt and Crossen – aka tailings – gravity flow to the lowest point of the pond surface were deposited as slurries into the Culmitzsch, for collection and pumping. The interim cover gradu­ Trünzig, and Helmsdorf/Dänkritz tailings manage­ ally evolves into a load-bearing surface suitable for ment facilities. Design of suitable stabilisation strate­ future remedial action. gies was not an easy thing to do since there were no experiences available in Germany or abroad on how to address tailings pond remediation of that order of magnitude. Scientific investigations and studies as well as pilot-scale tests had to be performed before informed decision-making was feasible. In develop­ ing promising remedial strategies, Wismut also sought the advice and expertise of foreign experts. In the end, in cooperation with the regulatory bodies and their consultants, “dry” in situ remediation with partial dewatering of the tailings was identified as the preferred option, since it presented the optimum trade-off between environmental benefit and costs. Based on this option, the remedial concept provides for the in situ remediation of all three tailings man­ Interim covering of Tailings agement sites involving the removal of the superna­ tant water and the capping of the tailings ponds with The next remedial step to follow is contouring. soil materials. Dam slopes are flattened wherever required for stabil­ ity or erosion protection reasons. The profile of pla­ To a large extent the technology of cover build­ teau areas is regraded in a way to allow natural sur­ ing had to be designed by Wismut themselves. In a face run-off. Given that deep fine-grained tailings first step following the removal of the supernatant sludges in particular will drain very slowly over ex­ water, a circa 1.5 metre thick interim cover was tended periods of time under the ap­­plied superim­ placed on top of the exposed tailings surface. As a posed load, so-called deep-reaching vertical drains rule, and this applies in particular to zones of fine- are driven through the interim cover down into the grained tailings, permeable waste rock, sand or grav­ tailings in order to enhance settlement that comes el are used to build the interim cover. along with drainage. Basically, settlements and defor­ mations should have faded away for the most part Covering the clayey-silty fine-grained tailings before the final cover is put in place. To achieve this was a formidable challenge. In contrast to the solid goal, drains are driven down up to locally ca. 25 to 30 sandy-grained tailings of the beach areas, here the metres below the tailings surface. low load-bearing capacity of the subsoil did not allow a straightforward placement of the cover material. In Eventually, the contoured surfaces are capped order to build a load-bearing surface for follow-up with 1.5 to 2 metres of final cover. Its primary pur­ operations, the exposed fine-grained tailings were pose is to control the infiltration of precipitation into covered with geotextile and geogrid materials. The the tailings in order to minimise the generation of geotextile primary capping provides sufficient load- contaminant-bearing seepage. Final covers of tailings bearing capacity for the operation of low-weight man­agement­­ areas basically feature an identical se­ equipment used to stitch up to 5 metres long wicks quence of layers, namely recultivation and storage (aka vertical drains) into the tailings. It also serves as a layer and infiltration barrier which may vary in thick­ support pad for the placement of the interim cover. ness or compaction depending on the properties of 13

Schematic diagram of interim cover placement on tailings pond the tailings material. Landscape planning for the Federal Mining Act. This does not compellingly imply, reuse of covered tailings provides for afforestation of however, that the proper shaping of the ground sur­ subareas as well as for the preservation of open grass­ face would tantamount to the restoration of pre-min­ land areas. ing conditions. In practice, the development of con­ cepts for the reuse of individual areas at Wismut is Concept for the handling of industrial guided by existing regional land development and buildings and facilities zoning plans. The actual need for remediation of an area is determined by the degree of the established After termination of uranium production there was contamination and the type of envisaged reuse. The no further use for most industrial buildings and facili­ release of areas for housing development, for indus­ ties. Only few units are still being used for ongoing trial, commercial, agricultural or forestry reuse is pri­ remedial work. These units will also be dismantled marily subject to compliance with the criteria recom­ and demolished once remediation will be completed. mended in the radiological protection. The concept for dismantling and demolition stipu­ lates that radioactively or chemically contaminated scrap and demolition rubble shall be disposed of within tailings management areas and waste rock piles. Uncontaminated scrap and scrap decontami­ nated by sand blasting shall be recycled. In contrast, uncontaminated demolition rubble shall be used for road construction purposes on reclaimed Wismut areas.

Concept for the reuse of rehabilitated areas

Areas contaminated or otherwise affected by mining activities and being attributed to Wismut have to be prepared for profitable reuse in compliance with the Green space at Kanigsberg, Ronneburg Operations Office (2009) 14 2 Remediation goals and concepts

In accordance with regional land development tailings dewatering purposes as well as for seepage and zoning plans, forests or green spaces are the pre­ from covered tailings management areas. Since these ferred types of reuse for the vast majority of areas waters are radioactively and chemically contaminat­ rehabilitated by Wismut. Only a few remediated ed they have to be treated in water treatment plants plant areas are eligible for commercial or industrial prior to discharge into receiving streams. reuse. Wismut operates eight water treatment plants. The concept for the remediation of waste rock Six of them use a flowsheet of precipitation with lime. pile footprints, plant areas and roadways and railbeds By addition of milk of lime, barium chloride, and iron basically stipulates that all ground contamination be chloride heavy metals, uranium, radium, and arsenic removed. On cleaned-up areas, foundations of demol­ are removed from the feed water as a low solubility ished buildings and facilities are removed down to a precipitate. Water treatment residues are disposed of minimum depth of 1.5 metres below ground level. in engineered cells in waste rock piles and tailings management areas. The two exceptions are the unit Concept for the handling of for the treatment of seepage from waste rock pile contaminated waters #371 at the Schlema site and the unit for the treat­ ment of the flood water from the Pöhla mine. At the Both during controlled mine flooding and after its Pöhla site, contaminants are precipitated by addition completion, flood waters will daylight which are con­ of barium and iron chloride without lime slurry; and taminated with uranium, radium, heavy metals, and the seepage from waste rock pile #371 is treated in an arsenic. The same is true for supernatant and pore ion exchange unit. waters which have to be removed by pumping for

BaCl2 CO2 HCl FeCl Feed 3 Milk of Lime 2 Flocculant

air HCl

1 4 3

7 5 6

1 Air blower Cement 2 CO strip column 2 Discharge to 3 Neutralisation tanks Culmitzsch 4 Lamella thickener 8 5 Filter 6 Storage tank To storage facility 7 Plate and frame filter 8 Mixing machine 9 9 Transport container

Flowsheet of the Seelingstädt water treatment plant using the lime precipitation process. 15

3 Engineering services, licensing process, monitoring

Comprehensive planning work is required to trans­ 3 Safe working conditions and protection of the late remediation concepts into actual remedial action. public during the execution of the required Such planning is in many cases based on detailed remedial operations, engi­neering services which, for the most part, also serve to underpin licence applications. The broad 3 Total rehabilitation expenditure including fol­ variety of remedial goals is reflected in the range of low-up long-term care and maintenance tasks, engineering branches and supporting applied natu­ and ral sciences involved: mining, geotechnics, soil me­ chanics, mine surveying, civil engineering including 3 Public acceptance. statical calculation, chemical engineering, process engineering, plant construction, electrical engineer­ Moreover, engineering services served as a basis for ing, measurement and control systems engineering, optimising work processes and enhancing quality transportation, hydraulics, road construction, energy control. supply, logistics, forestry as well as radiological pro­ tection. Science applications comprise geology, hy­ Engineering services not available at Wismut are drogeology, radioecology, and me­­te­­orology. Mathe­ being contracted out to recognised specialised firms matical modelling is used to assess the impact of vari­ to profit from their expertise. ous remedial options on water, air and soil quality as well as radiation exposure of critical groups of the Already at the time when mining operations public. ceased 20 years ago, Wismut sought contact with in­ ternationally operating engineering firms in the field Initially, these engineering services were aimed at of mine remediation with a view to enhancing the company’s mine engineering expertise and making it 3 The development of various remedial options, available for integration into its conceptual planning. In the meantime, Wismut’s mine remediation know- 3 Performing technical feasibility studies, and how is in demand nationally and internationally. A case in point is Wismut’s cooperation with the Czech 3 Investigating the efficiency and sustainability of company DIAMO in remediating the abandoned in the proposed remedial options. situ leach mines of Stráž pod Ralskem and Königstein and optimising treatment options for effluents from The findings served as a basis in the process of choos­ flooded uranium mines. In Hungary, the Mecsek-Öko ing a preferred option which in addition to technical company successfully terminated the rehabilitation feasibility would also comply with requirements of uranium mining legacies using Wismut know-how regarding and expertise. Remediation of the Sillamäe tailings

+0.1

Surface Contouring 0.0 -0.1 Sandy Tailings -0.2

Fine -0.3 Tailings -0.4 Bed Rock -0.5

-0.6 N S -0.7 m

Numerical settlement computation for Culmitzsch tailings pond 16 3 Engineering services, licensing process, monitoring

Monitoring along Postersteiner Sprotte

pond of the SILMET processing plant in Estonia was successfully completed in 2008 after some 10 years of project duration, with Wismut GmbH acting as plan­ ning advisor and consultant.

Briefing of regulatory agencies early on in the engineering planning stage has turned out to be con­ ducive to speeding up the licensing process, as it allows an informed discussion of technical and legal issues with the experts of the licensing authorities in Saxony and Thuringia.

Starting in 1990, Wismut has submitted more than 8,000 licence applications. Some 4,300 licences were granted in Saxony, approximately 3,700 in Thu­ ringia and ca. 60 licenses were awarded for cross-bor­ der clean-up. Almost half of the licences were granted Mobile measuring station for radon, dust, and precipitated dust under the provisions of the mining legislation, and about 1,000 permits each were awarded under radia­ sideration. To this end, local government representa­ tion protection legislation and water legislation, tives and Wismut GmbH meet at regular intervals. respectively. Permits granted under environmental protection legislation were in excess of 1,300. On behalf of the Federal Ministry of Economics and Technology (BMWi) a third party consultant Coordination of remediation planning with com­ which is mandated to assess the implementation of munities in the area is of particular importance. To decommissioning and remediation measures for the extent possible, reclamation at Wismut sites has solid practice and cost efficiency is also monitoring to take local and regional land use planning into con­ the licensing process. For more specific issues, the 17

Federal Institute for Geosciences and Natural Re­ parameters established from cover systems of waste sources and their expertise come into line. The Federal rock piles and tailings management areas to confront Ministry for the Environment, Nature Conservation their evolution with engineering and model calcula­ and Nuclear Safety (BMU) exercises federal supervi­ tion forecasts. Based on monitoring results, changes sion over licensing under radiological protection leg­ in environmental impacts occurring in the course of islation of the Free States of Saxony and Thuringia. In remediation are recorded, recorded data are stored in this respect, the BMU utilises the expertise of the data banks, and the findings are documented in re­ Federal Office for Radiation Pro­­tection (BfS) and con­ ports submitted to the regulators and the public. In sultants. this way, compliance with legal and regulatory stand­ ards and legislation is documented and the remedial Impacts and results of remediation activities are success made obvious. registered by a comprehensive monitoring system. Moni­­toring comprises radioactive and non-radioac­ By the end of 2010, Wismut operated a total of tive substances in water, soil and air. In addition, some 2,000 measuring stations. These stations moni­ meteorological data are collected and soil physical tor the atmosphere (radon, dust, long-lived radionu­

Air Pathway 100 1,600 90 1,400 80 1,200 70 60 1,000

50 800

40 Radon 600 Used air 30 400 20 10 200

0 0 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

Used air, 109 m3 Radon, 1012 Bq

Water Pathway 35 20 18 30 16 25 14 20 12 10 15 8 Water 10 6

4 Radium, Uranium 5 2 0 0 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

Water, 106 m3 Uranium, t Ra-226, 109 Bq

Source: Wismut GmbH

Evolution of releases via the atmospheric and aquatic pathways 18 3 Engineering services, licensing process, monitoring

Groundwater monitoring, Königstein

clides, both dust-borne and in precipitated dust) as needs of long-term post-remediation monitoring. well as receiving streams and groundwater (radionu­ Besides groundwater measuring points they also clides, heavy metals, further contaminants). Other comprise measuring stations for surface water and measuring networks are operated to register poten­ seepage to ensure long-term hydrological and hydro- tial movements at ground surface which could be chemical monitoring of individual objects or groups caused by the collapse of underground cavities, tail­ of objects. Any measuring station not eligible for inte­ ings dewatering or mine flooding. Soil and biomass gration into the key measuring networks for the sampling is conducted to track contamination by aquatic pathway shall be gradually placed out of ser­ radionuclides or other contaminants. vice. Depending on remedial progress at the various sites, this process will continue for several years and The number of required measuring stations will will certainly not be completed prior to the full reme­ decrease with further progress of remedial work and diation of the Culmitzsch tailings management site. the transition of reclaimed objects into the post-reme­ dial phase. At the end, only measuring stations will Measurement results registered to date demon­ remain active which are required for key measuring strate a significant improvement of environmental networks. These networks are designed to meet the quality. 19

4 Remediation sites

Ronneburg Remediation concepts

Initial situation Following approval by the regulatory bodies, remedia­ tion of mining legacies in the Ronneburg mining dis­ When uranium ore mining was terminated on Decem­­­ trict was implemented on the basis of the subsequent ber 31, 1990, the Ronneburg site comprised the min­ concepts: ing units of Schmirchau, Paitzdorf, Beerwalde, and Dro­sen. The Schmirchau mining unit also comprised 3 Mines: Removal of substances with the potential to the Reust mine and the worked-out Lichtenberg open pollute the incoming groundwater (grease, oil etc.) pit, and the Beerwalde unit also comprised the Kor­ and flooding up to natural groundwater levels. bußen mine. In 1991/92, these units were gradually merged to form the Ronneburg Rehabilitation Unit as 3 Buildings and Structures: Complete dismantling from January 1, 1993. and demolition.

When mining was terminated the legacies left 3 Lichtenberg Open Pit Mine: Backfilling with behind at Ronneburg comprised the pit sites with a waste rock material. total of 38 major shafts, 3 adits, mine drifts of a total length of 1,043 kilometres and open mine workings of 3 Waste Rock Piles: Relocation and concentration 26.7 million cubic metres, as well as the residual Lich­ at one single location each north and south of the tenberg open pit with a residual volume of 84 million motorway. cubic metres. Approx­imately 188 million cubic metres of waste rock and overburden were scattered among 3 Operation Areas: Preparation for reuse of former 16 mine dumps. Plant areas including waste rock pile mining areas predominantly for agricultural and footprints and the surface of the residual Lichtenberg forestry purposes as well as for industrial and open pit extended over an area of 1,670 hectares. The commercial reuse. groundwater depression cone due to mining opera­ tions extended for more than 50 square kilometres. 3 Contaminated Waters: Capture of all daylight­ ing contaminated waters and treatment to reach compliance with authorised discharge limits.

Conical piles and Ronneburg plant area before remediation (1991) 20 4 Remediation sites

Remediation achievements workings are completely flooded. Replenishment of dewatered pore spaces, fissures and cracks of the Flooding of underground mines cone of depression with groundwater and the subse­ Flooding of the mining fields located to the north and quent groundwater rise to its natural level is still south of the motorway of the Ronneburg mining dis­ going on. trict represented a major challenge. Elaborate pre­ paratory work, both scientific and technical, was Modelling of anticipated flood behaviour for the required to assess the impacts of mine flooding on mining districts located north and south of the aquifers and surface water bodies located down­ motorway had revealed very early on that groundwa­ stream of the mines. ter replenishment would very probably result in groundwater emergence in the Gessental valley and The preparatory studies revealed that prior to that this groundwater would be contaminated by flooding the mines all pit shafts and near-surface rock contact in the flooded mine workings. Preparing mine workings had to be backfilled with cohesive for such a scenario, in 2001 Wismut established a stowing material down to a depth of 100 metres in groundwater collection system on the bottom of the order to preclude future surface subsidence. Identical Gessental valley and along the north-western edge of precautions had to be taken with regard to mining the Lichtenberg open pit mine. Zones along the cavities near protective pillars as well as beneath the Posterstein Sprotte and Beerwalde Sprotte creeks town of Ronneburg. Mine workings at the Beerwalde were identified as further potential decant areas. and Drosen subsites had also to be backfilled in order to protect aquifers located north of a geological fault The water collection system is a combination of zone („Crimmitschau fault“). Underground remedial horizontal and vertical drainage installations. Ground­­­ work initiated in 1991 was completed in 2000. Ap­ water intercepted by this collection system drains to prox­­imately 5.8 million cubic metres of mining cavi­ a pump station located in the Gessental valley from ties were backfilled. where is pumped via a 3.8 kilometre long pressure pipe to the Ronneburg water treatment plant. Once mine workings and pit shafts had been re­ mediated and backfilled by 1998, overall flooding of In August 2006, the groundwater had risen to the mining fields located south of the motorway was initi­ lowermost section of the groundwater collection sys­ ated. Flooding of mining fields located north of the tem. motorway commenced in 2000. In essence, all mine

Residual Lichtenberg open pit (1992) 21

Mound atop backfilled Lichtenberg open pit (2010)

Dismantling and demolition of structures Lichten­berg open pit. Uncontaminated or decontami­ and facilities nated scrap was sold. The termination of uranium ore mining made the mine hoisting complexes consisting of 19 pit shafts as Waste rock pile remediation and backfilling well as 19 mine ventilation shafts redundant. For the of open pit mine associated ore bins and conveyors, ore loading and Waste rock pile remediation at the Ronneburg site transportation facilities, substations, transformer sta­ was completed in 2008. Except for the Beerwalde tions, power grid for electric supply, boiler houses, mine dump and waste rock pile #381 in the Gessental distribution stations, steam pipe networks for heat valley, Diabashalde dump and all low-grade ore, waste supply, pumping stations, water storage tanks, waste rock and overburden piles were completely dug up water treatment plants, piping systems for drinking and removed. The ma­­terial contained in the waste water and process water supply as well as sewage rock piles located south of the motorway was used to management, repair shops and storage houses as well backfill the worked-out Lichtenberg open pit mine. as administrative buildings, kitchen buildings and The Drosen and Korbußen waste rock piles located staff restaurants and sanitary facilities there was no north of the motorway were dug up and banked further use at the Ronneburg site. Starting in 1991, against the Beerwalde waste rock pile (Table 1). facilities and buildings were dismantled and demol­ ished. To date, only the administrative buildings, Relocation of waste rock material into the worked- repair shops, and storage houses of the former Lich­ out Lichtenberg open pit mine resolved several prob­ ten­berg mine are still in use. In the meantime, all lems at one go. On the one hand, the worked-out other facilities and buildings of the former spaciously open pit mine was backfilled, which otherwise would laid out mining district are gone. have filled up with radioactively and chemically con­ taminated groundwater in the wake of mine flood­ By the end of 2010, dismantling and demolition ing. On the other, there was waste rock at some loca­ of facilities and buildings had generated some 70,000 tions which contained up to 5 per cent of pyrite which tonnes of scrap and 285,000 cubic metres of demoli­ forms acid when reacting with atmospheric oxygen tion rubble. Radioactively contaminated scrap as well and water. To avoid the need to intercept and treat as both radioactively and chemically contaminated acid drainage for decades to come, pyrite-laden waste demolition rubble were disposed of in the residual rock had to be concentrated at a single location and 22 4 Remediation sites

disposed of in a way that would preclude pyrite to were completed by the end of 2010. Engineered cells come into contact with atmospheric oxygen. Placing within the fill body will accommodate excavated con­ waste rock with elevated acid generation potential at taminated soil as well as immobilised water treat­ the bottom of the open pit mine did meet this ment residues from the Ronneburg water treatment requirement in an ideal manner since the backfilled plant. Forests and green spaces are the intended material would for the most part be submerged reuse options for this 222-hectare area. By the end of below the groundwater table once flooding was com­ 2010, afforestation had been completed on 51 hec­ pleted. Groundwater provides efficient shielding tares. A network of logging roads and hiking trails against access of air. totalling 19 kilometres will be established for forest management and tourism development around the The available pit volume of 84 million cubic “Schmirchau Height”. By the end of 2010, 17 kilome­ metres was too small to accommodate the total vol­ tres of that network were completed. ume of 132 million cubic metres made up of relocated waste rock (Table 1), excavated contaminated soil The rationale behind excavating and banking the and rubble from the demolition of buildings and Drosen and Korbußen waste rock piles against the structures. The surplus material was used to build up Beerwalde pile was similar to that for relocating the a mound atop the backfilled open pit. In commemo­ waste rock piles into the worked-out Lichtenberg ration of the Schmirchau community which had to open pit, namely to concentrate the waste rock mate­ make way for the development of the open pit mine, rial of the three piles located north of the motorway the mound is called “Schmirchau Height”. This land­ in a single location. This approach was more cost- scape feature and the reclaimed Nord­halde footprint effective than to remediate the three piles individual­ in the Gessental valley were integrated as „New ly in situ. Ronneburg Landscape“ into the grounds of the 2007 National Horticultural Exhibition. The final cover of the Beerwalde waste rock pile consists of 0.40 metre infiltration barrier and 1.5 The Lichtenberg fill body is being provided with metre moisture storage layer on top. Vegetation of a final cover of 1.6 metre thickness of which 91 per cent the newly created landscape feature finalised the

Waste Rock Relocation into Open Pit Lichtenberg

3 Gessen heap leach pile 1 Relocation: 1990–1995 Volume: 7.6 mill. m³

3 North waste rock pile 2 Relocation: 1998–2003 Volume: 31.3 mill. m3

3 Stacked waste rock pile 3 Relocation: 1993–2006 Volume: 70.1 mill. m3

3 Reust terraconic waste rock piles 4 Relocation: 2004–2007 Volume: 6.4 mill. m3

3 Paitzdorf terraconic waste rock piles 5 Relocation: 2005–2006 Volume: 8.0 mill. m3

Relocation scheme for waste rock piles south of A4 motorway at Ronneburg 23

Shift change during waste rock pile relocation into Lichtenberg open pit mine (1998) remediation of the Beerwalde waste rock pile in 2003. A fleet worth some 45 million euros of up to 75 mas­ Since then, young forest plantations have been grow­ sive earthmoving machines including dump trucks, ing vigorously. excavators, shovels, and dozers excavated and moved up to 40,000 cubic metres of waste rock material a Excavating and moving waste rock piles at the day in its heyday. Ronneburg site involved off-highway equipment.

Table 1: Waste rock pile remediation at Ronneburg site Type of Remediation Volume, 106 m3 Relocation Period Remediation in situ Beerwalde pile 4.5 Waste Rock pile #381 0.8 Diabashalde dump 0.2 Total 5 .5 Relocation into Lichtenberg open pit Absetzerhalde pile 70.1 1993 – 2006 Nordhalde pile 31.3 1998 – 2003 Conical piles Paitzdorf 8.0 2005 – 2006 Gessenhalde pile 7.6 1990 – 1995 Conical piles Reust 6.4 2004 – 2007 Waste rock pile #370 1.4 2003 Waste rock pile #4 1.1 2006 – 2007 Waste rock pile #377 0.4 2004 Schutzdamm Ronneburg 0.1 2007 – 2008 Total 126 4. Relocation to Beerwalde waste rock pile Drosen waste rock pile 4.0 1997 – 1999 Korbußen waste rock pile 0.5 2000 – 2001 Grand Total 4 5. 24 4 Remediation sites

Conical waste rock piles at Reust mine site before remediation (1991)

Operation areas and waste rock pile pile have been fully reclaimed. Remediation of the footprints Nordhalde, Absetzerhalde, Paitzdorf and Reust waste In 1992, an area of approximately 1,520 hectares at pile footprints will for the most part be finalised by the Ronneburg site was owned by Wismut GmbH. 2015. This property was for the most part composed of operation areas of the former mining units as well as In line with regional land development planning of waste rock footprints and roadways and railtracks. for Eastern Thuringia the reclaimed areas will be Of that total, some 1,100 hectares were in need of turned into forests and green spaces for the most part. remediation. The sites either had an elevated natural Operation areas of the former Beerwalde, Schmirchau, radioactivity or were contaminated with heavy met­ and Paitzdorf mining units were reclaimed for com­ als and hydrocarbons or showed multiple contamina­ mercial and industrial reuse. Installation of a photo­ tion by two or three of the above types of contami­ voltaic plant at the site of the former Schmirchau nants. Depending on concentration levels of the mining unit in 2009 is a case in point. Planning is hydrocarbons, the contaminated soil excavated dur­ under way for a second photovoltaic plant at the foot­ ing ground remediation was either integrated into print of the former Reust waste rock pile. Under the the fill body of the Lichtenberg open pit or disposed motto „Resurrektion Aurora“ an open-air museum of at the Lichtenberg disposal cell for materials with depicting the history of uranium mining by Wismut multiple contamination operated by Wismut. Given as well as a sculpture park were inaugurated at the that large quantities of soil with multiple contamina­ site of the former Drosen mining unit on the occasion tion were excavated from 1997 through 2001, Wismut of the national horticultural exhibition in 2007. established a biological treatment unit at Ronneburg where hydrocarbon decomposition was performed Collection and treatment of contaminated by bacterial oxidation. waters In August 2006, the groundwater had risen to the To date, some 830 hectares of former plant areas, level of the water collection system established in the roadways and rail tracks as well as waste rock pile Gessental valley. Parallel to the groundwater rise the footprints have been reclaimed. Operation areas and volume of intercepted groundwater has risen from waste rock pile footprints at the former Drosen and less than 20 cubic metres per hour at the beginning to Korbußen mining units as well as the footprints of a volume in excess of 400 cubic metres per hour. waste rock piles #370, #377 and of the Gessenhalde Previously unknown hydraulic shortcuts caused the 25

Footprint of the Reust waste rock piles after remediation (2010)­ emergence of contaminated groundwater in the discharged into the Wipse streamlet from where they Gessental valley at sites located outside the sphere of reach the Weiße Elster River. influence of the collection system where the system hence failed to intercept them. Locally emerging Since its commissioning, the plant has treated water is currently intercepted in near-surface drain­ some 17.5 million cubic metres contaminated surface ages and catchment ditches and then pumped to the run-off and groundwater. Capital costs for the con­ Ronneburg water treatment plant as well. In 2008 struction of the water treatment plant including the and 2009, contaminated groundwater emerged feeder pipe amounted to 17 million euros. Upgrading along the Postersteiner Sprotte and Beerwalder of the plant will require an additional 5 million euros. Sprotte creeks as predicted. In co-ordination with the regulatory authorities, temporary collection systems Outlook were established here as well. The water is piped to appropriate locations from where it is returned to the Remedial operations at the Ronneburg site will for mine. the most part be finalised by 2015. Work to be final­ ised by that date involves mainly area remediation To terminate the temporary water catchment projects. Demolition of repair shops, storage houses, measures in the Gessental valley, the existing ground­ administrative buildings, associated roadways and water collection system will have to be enhanced. rail tracks as well as a number of water storage ponds This in turn will require the lowering of the flood which are currently still required for the execution of water level by about 25 metre. However, before pro­ remediation measures is slated to follow after 2015. ceeding with this plan, the capacity of the Ronneburg Subsequent to this work, the cleared areas will be water treatment plant has to be expanded to treat renaturated. 750 cubic metres per hour. The upgraded plant is expected to come on stream in autumn of 2011. Long-term tasks to be accomplished after remedi­ ation is complete will include water treatment, moni­ The Ronneburg water treatment plant is using toring as well as care and maintenance duties. The lime precipitation to treat the contaminated waters. period of time during which water treatment will be Immobilised water treatment residues are disposed required cannot be specified at the present time. within the Lichtenberg fill body. Treated waters are 26 4 Remediation sites

Seelingstädt The ore processing residues, also known as tail­ ings, were discharged into the Trünzig tailings man­ Initial situation agement facility from 1960 through 1967 and from 1967 till the end of ore processing in 1990 into the At the time when ore processing was terminated at Culmitzsch tailings management facility. Due to the the end of 1990, the Seelingstädt site comprised the process technology, each facility was divided by a Seelingstädt mill as well as the two tailings manage­ dyke into two ponds for a separate storage of residues ment areas of Culmitzsch and Trünzig. Commis­ from the acid and alkaline leaching process. sioned in 1960, the Seelingstädt mill was Wismut’s largest and most advanced processing site. The mill The Trünzig and Culmitzsch tailings manage­ processed a total of 110 million tonnes of ore coming ment facilities covered a total surface of about 350 for the most part from Ronneburg, but for some time hectares and contained some 104 million cubic also from the Aue district as well as from Königstein metres of tailings (Table 2). In 1992, the volume of and Dresden-Gittersee. The site of the mill was chosen supernatant water in the ponds amounted to some for its proximity to the two worked-out open pit mines 2.4 million cubic metres. of Culmitzsch and Trünzig which could be used to accommodate the processing residues. Both tailings ponds are bounded by dams and overburden dumps. The dumps were piled up during The Seelingstädt processing facility occupied an the development of the Culmitzsch and Trünzig as area of 83 hectares. Of that total some 25 per cent well as of the Sorge-Settendorf and Gauern open pit were built-up. In addition to ore processing facilities, mines. Out of a total of 9 overburden dumps, only the the premises also contained a sulphuric acid plant Waldhalde, Jashalde, Lokhalde and Südwesthalde and an industrial power plant. On balance, there dumps with an overall volume of 55 million cubic were more than 300 buildings. Depending on the metres are still owned by Wismut (Table 3). type of ore, the Seelingstädt mill either used an acid (sulphuric acid) or alkaline (sodium carbonate) flow Some slope sections of the Waldhalde and Süd­ sheet. westhalde dumps have to be flattened to achieve last­

Seelingstädt processing plant (1991) 27

Table 2: Parameters of Culmitzsch and Trünzig tailings management areas (1990)

Culmitzsch Trünzig Tailings area ha 234 115 Pond A ha 158 67 Pond B ha 76 48 Tailings volume 106 m3 85 19 Pond A 106 m3 61 13 Pond B 106 m3 24 6 Solids 106 t 91 19 Pond A 106 t 64 13 Pond B 106 t 27 6 Maximum Tailings thickness Pond A m 72 30 Pond B m 68 24 Volume Supernatant water 106 m3 2.4 0.08 Pond A 106 m3 2.1 – Pond B 106 m3 0.3 0.08 Maximum Water depth Pond A m 7.9 – Pond B m 2.4 2.3 ing slope stability. Material at other parts of the Wald­ 3 Tailings Management Facilities: Removal of halde dump must either be covered or removed for supernatant water, followed by interim cover compliance with radiation protection regulations. placement, contouring, placement of final cover on tailings; vegetation and afforestation of cov­ Remediation goals/concepts ered tailings.

Following approval by the licensing authorities, 3 Overburden Dumps: Flattening of low-stability remediation of legacies at the Seelingstädt site was slopes, relocation of low-grade ore from Wald­ conducted on the basis of the subsequent concepts: halde, and some excavation of material to be used for recontouring and final cover placement 3 Plant Facilities and Buildings: Except for the of both tailings management areas. Afforestation laboratory building, dismantling and demolition of newly recontoured dumps to be left in place. of all other structures.

Trünzig tailings management facility (1991) 28 4 Remediation sites

Table 3: Parameters of overburden dumps at Seelingstädt (1990) Footprint area Max . Height above Volumen ha footprint in m 106 m3 Lokhalde dump 81 23 16 Waldhalde dump 73 36 21 Jashalde dump 22 23 4 Südwesthalde dump 42 41 14 Total 55

3 Operation Areas: Rehabilitation of former plant Scrap from buildings and facilities where verifia­ premises and of Lokhalde footprint for reuse as bly no radioactive materials were handled, e.g. the forests and green spaces. sulphuric acid plant and the industrial power plant, were directly recycled, certified by a declaration of 3 Contaminated Waters: Treatment of contami­ plausibility. Steel scrap from radiation protection nated supernatant waters as well as contaminat­ areas, on the other hand, had to be measured for total ed seepage and run-off intercepted near tailings alpha surface activity using a procedure specifically management areas in Seelingstädt water treat­ designed for Wismut applications. In case of surface ment plant. Treatment of seepage will have to con­ activity levels below the release standard of 0.5 Bec­ tinue until compliance with discharge standards. querel per square centimetre the scrap was released for smelting. Large quantities of contaminated steel Remediation achievements scrap could be recycled after decontamination by sand blasting. Decontamination waste and unusable Plant facilities and buildings contaminated scrap were disposed of in engineered Dismantling and demolition of plant facilities were cells at the Culmitzsch tailings management facility for the most part carried out from 1997 to 2003. and plugged with concrete. Demolition work generated some 60,000 tonnes of scrap and 230,000 tonnes of demolition rubble. An unpolluted sector of the former plant premis­ es was sold and is now used for commercial purposes. Contaminated demolition rubble was crushed The laboratory and pilot-test building is the only sur­ and used to build interim covers on tailings manage­ viving structure on the remaining premises. Also still ment areas. Uncontaminated rubble was also used to in operation is the unloading station of the Wismut build roadways across tailings management areas. branch line which is used for the supply of sand and

Trünzig tailings management facility (2010) 29

Culmitzsch tailings management facility (2010) gravel destined for the interim cover of the material. Some 3.5 million cubic metres of sand, grav­ Culmitzsch tailings management area as well as top­ el, and material excavated from the Lokhalde dump soil destined for the recultivation of the reclaimed were needed to complete the interim cover on the plant premises. larger Culmitzsch tailings management facility.

Tailings management facilities Started in 2001, recontouring of dam and plateau Initial remediation work at the Culmitzsch and Trün­ sections at the Trünzig tailings management facility zig tailings management facilities began as early as is nearing completion. Final cover placement across 1990 and 1991, respectively, when interim covers were the entire facility is to be completed by 2012; current­ placed on exposed tailings beaches in order to elimi­ ly some 85 per cent have been put in place. The gently nate immediate risks and reduce contaminant disper­ undulated plateau area was designed in a way to allow sal by windblown dust. In the period that followed, surface run-off from pond A to discharge to­­wards the supernatant water was removed and the areas ex­ Culmitzsch lowland and from pond B to­­wards the posed due to the falling water level were then gradu­ Finkenbach valley. Contouring and final cover build­ ally capped with an interim cover. ing at Trünzig tailings management facility used up some 6.5 million cubic metres of overburden material. Placement of interim covers on ponds A and B of the Trünzig tailings management facility was final­ Contouring work on the Culmitzsch tailings man­ ised in 1995 and 2001, respectively. The interim cover agement facility began in 2007 by flattening the Nord­ on pond B was completed in 2006. Full interim cover damm for stability reasons. Forestry roads were built on pond A is slated for 2014; some 95 per cent are on the berms of the recontoured Norddamm and the presently in place. Building the interim cover of the adjacent Jashalde dump as well as along the toe of the Trünzig tailings management facility consumed Nord­­damm. To collect surface run-off riprap channels some 1.1 million cubic metres of earthen material, for and ditches were constructed. Work on the Nord­ the main part excavated during the renaturalisation damm is completed. Contouring work is under way of the Finkenbach valley which during production on pond B. Süddamm and pond A are slated to follow times was used as a dumping ground for overburden in a couple of years. According to current planning, 30 4 Remediation sites

contouring and final covering of the entire tailings ing at the Trünzig and Culmitzsch tailings manage­ management facility is to be finalised by 2022. In ment facilities is being provided by the complete addition to the 3 million cubic metres already used excavation of the Lokhalde dump and the partial ex­ up, some 18 million cubic metres more of overburden cavation of the Waldhalde and Südwesthalde dumps. material will have to be moved to the Culmitzsch tail­ The Lokhalde dump will be completely excavated and ings management facility for contouring and cover removed by 2021. building purposes. Excavation of the Waldhalde dump began in July In the end, the plateau section of the Culmitzsch 2008. In an initial step the dump slope is flattened. tailings management facility is to emerge as a slightly For that purpose, dumped material is removed from undulating landscape which discharges its run-off bottom right up to the top. The excavated material is towards north. The reclaimed areas are to be afforest­ used for contouring the Cul­mitzsch tailings manage­ ed for the main part with coniferous and deciduous ment facilities. To date, some 1.9 million cubic metres trees to form mixed woodland. Partial areas along the of dumped material have been excavated from the external dams and the pond centres are designed as Waldhalde dump and moved to the Cul­mitzsch tail­ green spaces. ings management faci­lities for contouring. Before contouring will be finalised by 2019, an additional Overburden dumps volume of some 3.6 million cubic metres is slated for Material needed for contouring and final cover build­ excavation and removal.

Reuse concept for Culmitzsch tailings management facility 31

unloading facility will be needed up to that point to conduct final remedial operations.

Collection and treatment of contaminated waters Seepage collected by rows of wells and deep drains located around the Trünzig and Culmitzsch tailings management areas as well as the remaining superna­ tant water from Culmitzsch A are merged in a storage and homogenisation lagoon and then pumped to the Seelingstädt water treatment plant.

At the beginning, supernatant water and seepage were treated in the former uranium ore processing facility at the Seelingstädt site. In 2000, a new water treatment plant was erected next to the Cul­mitzsch Seelingstädt water treatment plant (2004) tailings management facility; that plant went on stream in 2001. It has a design capacity of 300 cubic One slope of the Südwesthalde dump is also con­ metres per hour and uses a lime precipitation flow sidered to lack long-term stability in its present state. sheet. Water treatment residues are immobilised and During the period 2014 –2016 it shall therefore be flat­ stored in an engineered disposal cell within the peri­ tened by excavation and removal of material which meter of Culmitzsch B tailings management facility. will for the main part be used for building the final The treated waters are discharged into the Culmitzsch­ ­­­­ cover across the ponds of the Culmitzsch tailings bach creek from where they get into the Weiße Elster management facilities. River.

Following completion of the measures aimed at Since it came on stream, the new plant has treat­ enhancing slope stability and providing cover materi­ ed some 22 million cubic metres of contaminated als, forests will be restored on the Waldhalde and Süd­­­ waters from the Trünzig and Culmitzsch tailings westhalde dumps. management facilities. Investment expenditure for the construction of the Seelingstädt water treatment Areas plant was in the order of 8 million euros. Significantly contaminated areas within the cleared plant premises of the Seelingstädt mill were rehabili­ Outlook tated by soil replacement. A similar approach will be used at the cleared footprints of the Lokhalde, Wald­ After completion of remedial operations, forests and halde, and Südwesthalde dumps. green spaces established on the covered Trünzig and Culmitzsch tailings management facilities as well as The excavated contaminated soil from plant area the renatured plant premises and dump footprints rehabilitation is used either as interim cover material will have to be managed, i.e. post-remedial care and or for contouring purposes at the Culmitzsch tailings maintenance will have to be provided. Further long- management facility. term tasks are water treatment and monitoring. See­ page levels from the Trünzig and Culmitzsch tailings Remediation of the areas of the former plant management facilities may drop over time; but the premises is almost finalised; out of a total of 83 hec­ seepage flow will never dry up completely; and seep­ tares, 70 hectares were reclaimed by the end of 2010. age quality will not comply with standards for direct Completion of remaining work will take until 2017, discharge into Culmitzschbach creek for an extended because items up for demolition like the retention period of time. As a consequence, water treatment ponds, factory roads, parking spaces, and the railway will have to be continued for a very long period of time. 32 4 Remediation sites

Crossen/Helmsdorf Dänkritz II tailings management facilities. The 3 tail­ ings management facilities cover a total area of some Initial situation 227 hectares and contain approximately 57 million cubic metres of tailings (Table 4). The Crossen processing plant was established in 1950 on the premises of the Leonhardt paper factory. Pro­ The Helmsdorf tailings management facility was cessing of uranium ores ceased already at the end of established by the damming of two valley locations. It 1989 for economic considerations. was operational from 1958 to the shutdown of ore processing in 1989. Since the Zwickauer Mulde River was running right through the 21 hectares plant premises, the site The Dänkritz I and Dänkritz II tailings manage­ was cut into two distinct areas. The 17 hectares area ment facilities were established in the early 1950ies at on the right bank of the Mulde River was densely the site of two abandoned gravel pits located north of built-up and comprised the factory buildings of the the Helmsdorf tailings management facility. When processing plant, while the ore discharge and storage the latter was commissioned in 1958 the two Dänkritz facilities were on the left bank of the Mulde River. sites were closed. In 1990, the Dänkritz II tailings management facility was no longer owned by the The Crossen plant processed for the most part Wismut GmbH and it is not part of the company’s ores from mines in the Ore Mountains and from the remediation mandate. Ronneburg district as well as – until 1960 – from open pit mines near Seelingstädt. Until 1980, wet chemical The discarded waste rock from the radiometric as well as radiometric sorting and gravity concentra­ and gravitational ore processing was dumped on the tion methods were used for ore processing. Later, only Crossen waste rock pile. At the time when production the hydrometallurgical process was used. In total, was terminated, some 3.2 million cubic metres of resi­ some 74 million tonnes of ore were milled and 77,000 dues had accumulated on an area of 22 hectares, in­ tonnes of uranium produced in Crossen. cluding ca. 0.5 million cubic metres of tailings from hydrometallurgical processing during the early years Residues of the hydrometallurgical process were of operation until 1952. disposed as slurries in the Helmsdorf, Dänkritz I and

Crossen ore processing plant (1991) 33

Table 4: Parameters of Helmsdorf and Dänkritz tailings management areas (1990)

Helmsdorf Dänkritz I Dänkritz II Total Tailings area ha 200 20 7 227 water covered ha 116 12 3 131 Volume supernatant water 106 m3 5 0.25 0.05 5.3 Tailings volume 106 m3 45 5 1 50 Solids 106 t 50 7 1 58 Maximum Tailings thickness m 55 23 19 Maximum Water depth m 14 2 2

Remediation goals/concepts 3 Operation Areas: Rehabilitation of the former Remediation of the legacies left behind at the Crossen plant premises and of the Crossen waste rock pile site was implemented on the basis of the subsequent footprint, design as alluvial landscape and flood concepts: retention area.

3 Plant Facilities and Buildings: complete dis­ 3 Contaminated Waters: Treatment of contami­ mantling and demolition of all structures. nated supernatant waters and of seepage collect­ ed near tailings management facilities in the 3 Helmsdorf and Dänkritz I Tailings Mana­ge­ Helmsdorf water treatment plant. Seepage treat­ ment Facilities: Removal of supernatant water, ment to be continued until compliance with dis­ followed by interim cover building, contouring charge standards. and final covering of the tailings; vegetating for erosion protection and afforestation of covered Remediation achievements tailings areas. Plant facilities and buildings 3 Crossen Waste Rock Pile: Complete relocation 19th century buildings beyond repair, any reuse was to the Helmsdorf tailings management facility ruled out from the outset. Therefore, facilities and and use of the waste rock for interim cover and buildings were completely demolished. contouring purposes.

Remediated Crossen plant area with waste rock pile removal in progress (2008) 34 4 Remediation sites

Helmsdorf and Dänkritz I tailings management facilities, Crossen site (2010)

Dismantling of some technical equipment had Remediation work in the proper sense began in begun as early as 1989. Dismantling and demolition of 1996 after commissioning of the new water treatment large and sophisticated equipment was contracted to plant at the Helmsdorf site, where the pumped away specialised firms. Dismantling and demolition of all supernatant water could be treated and hence the above ground buildings and facilities was accom­ water level in the Helmsdorf tailings facility could be plished by 2006. gradually lowered. During the following years the ex­ posed tailings areas were capped with an interim cover. Dismantling and demolition work generated 26,500 tonnes of scrap and 62,300 cubic metres of By the end of 2010, some 201 hectares had been demolition rubble; of that total, 21,000 tonnes and capped with 1.5 metre interim cover; this effort had 49,000 cubic metres, respectively, were contaminated. consumed 2.9 million cubic metres of waste rock and Radioactively or chemically contaminated scrap and sand and gravel, respectively. The interim cover is demolition rubble were first dumped at the Crossen now 98 per cent complete, with a small residual lake waste rock pile for interim storage and subsequently remaining atop the pond’s deepest point. moved to the Helmsdorf tailings management facility. At Helmsdorf the rubble was used for interim covering Work began in 2002 at the Helmsdorf tailings purposes and the scrap was disposed in engineered ma­­­­­nagement facility to establish a final contour de­ cells within the covered tailings beach areas. Un­ signed as an undulating landscape of hills and swales. contaminated scrap was sold, the rubble for the most This involves the slope flattening and partial excava­ part used for roadwork on site. tion of embankment dams. The material removed this way together with mineral soil from nearby bor­ Helmsdorf and Dänkritz I tailings row pits is used to shape the hills of the plateau area. management facilities Since 2005, the contoured areas are in the process of In order to mitigate immediate risks, interim action being capped with a final cover of 1.5 metre of miner­ undertaken immediately after termination of produc­ al soil. The plateau relief is designed to allow dis­ tion focused on covering exposed sandy tailings to charge of surface run-off towards­­ the Wüster Grund prevent windblown dust. Moreover, seepage collec­ dam and towards Ober­rothen­bach. A minor portion tion systems were extended. of the run-off will discharge towards the Zinnbach creek, just like the run-off from the Dänkritz I tailings 35

management facility where contouring and cover cubic metres of contaminated fill and excavated soil, placement were finalised in 2007. 115,000 cubic metres of contaminated demolition rubble, and more than 3,000 cubic metres of multiple Contouring and final cover placement at the contaminated materials. On balance, nearly 268,000 Helmsdorf and Dänkritz I sites are to be finalised by cubic metres of uncontaminated soil materials were 2017. Some 6 million cubic metres of material have needed as replacement. The area is now vegetated been used for this purpose to date. An additional vol­ and blends in with the floodplain landscape of the ume of 3 million cubic metres will be required to Zwickauer Mulde River. complete the task. Following removal of contaminations identified The reclaimed area shall be used for forestry and in the ground, the 22 hectares footprint of the grassland purposes. Crossen waste rock pile, located immediately along the Zwickauer Mulde River, is to be turned into green Crossen waste rock pile space and shall serve as a polder for flood control. The Crossen waste rock pile has already been relocat­ Remediation of the footprint and dismantling of the ed to the Helmsdorf/Dänkritz I tailings management pipe conveyor are to be completed by 2016. facility at nearly 85 per cent. Excavation of the re­ maining waste rock material and of the soil from foot­ Collection and treatment of contaminated print remediation is to be terminated by 2015. waters Until 1995, supernatant water and seepage were Since 1997, haulage of waste rock and crushed de­ treated in an existing treatment plant at the Crossen molition rubble to the Helmsdorf tailings management site. In 1995, the Helmsdorf water treatment plant facility is conducted by pipe conveyor over a distance was the first of the state-of-the-art treatment plants of of 1.8 kilometres, which minimises environmental Wismut GmbH to come on steam. The plant had a impacts as opposed to truck haulage on public roads. design capacity of 250 cubic metres per hour. In the early years, it used a highly complex process to remove Areas uranium, radium, and nonradioactive contaminants Initiated in 2003, remediation of plant premises of separately from supernatant and seepage waters. the former Crossen uranium ore processing unit was Treatment sludges were immobilised separately and completed by 2008. Contaminated soil was excavated disposed at a licensed location within the Helmsdorf and replaced by unpolluted earthen materials. Gen­ tailings management facility. In order to simplify the erated as a result of remediation work were 294,000 process and for cost reasons, precipitation with lime

Pipe Conveyor, Crossen site (1996) 36 4 Remediation sites

was introduced in 2002. Presently, the two-line facili­ Königstein ty has a design capacity of 200 cubic metres per hour. Immobilised residue sludges continue to be disposed Initial situation at the Helmsdorf tailings management facility. Treated waters are discharged to the Zwickauer Mulde River. Prospecting for uranium in Upper Cretaceous sand­ stones of the Elbe rift valley southeast of Dresden Construction costs for the Helmsdorf water treat­ began in the early 1960s. In 1963, the Königstein de­ ment plant were in the order of some 20 million euros. posit was discovered. Mine development commenced Since it came on steam, the Helmsdorf water treatment as early as 1964 and eventually comprised 5 pit shafts plant has processed some 21 million cubic metres of and 7 ventilation raises as well as headings, extraction contaminated supernatant and seepage water from drifts, and cross-cuts on 4 levels. The surface area af­ the Helmsdorf and Dänkritz I tailings management fected by mining operations extends over ca. 6 square facilities. kilometres near the localities of Königstein, Bielatal, Langenhennersdorf and Struppen. Outlook Systematic operations were undertaken in 1967 After completion of remedial operations, the covered using conventional underground mining methods. areas of the Helmsdorf and Dänkritz I tailings man­ agement facilities which will be used for the most part A total rock volume of some 9 million cubic metres for silvicultural purposes, will have to be managed, including about 5 million cubic metres of ore were i.e. post-remedial care and maintenance will have to mined by conventional mining. The ore was hauled be provided. Further long-term tasks are water treat­ by ropeway to the Rottwerndorf loading station and ment and monitoring. Seepage from the Helmsdorf then by rail to the central ore processing facility at and Dänkritz I tailings management facilities may Seelingstädt. Waste rock from mine development and drop over time, but the seepage flow will never dry up conventional ore mining was moved to the Schüssel­ completely, and seepage quality will not comply with grund mine dump. standards for direct discharge into the Zwickauer Mulde River for an extended period of time. As a con­ Following development of an in situ leach techno­ sequence, water treatment will have to be continued logy, the mine shifted to full in situ leaching of urani­ for a very long period of time. um in 1984 as a response to decreasing uranium grades.

Königstein plant area (1994) 37

Leaching of the ore was performed with ground­ In addition to the requirement of remediating water to which sulphuric acid had been added. By and cleaning up the above ground legacies such as 1990, more than 55 million tons of sandstone had ore handling grounds, heap leach pads, buildings, come into contact with the leach liquor. When min­ plant areas, and the Schüsselgrund mine dump, the ing was terminated, a portion of the liquor remained task to minimise contaminant release in the wake of locked in the sandstone as pore water. Uranium was flooding the mine workings presents an enormous also extracted at 8 on-site leach pads from the ore challenge. that had been removed from underground in order to prepare for the in situ leach operation. Pregnant liq­ The mine flooding concept was based on the uor from underground leaching and from the heap awareness that flooding immediately after mine shut­ leach operation was piped to an above ground ion down would entail high environmental risks. Un­­con­ exchange unit which produced a liquid uranium con­ trolled flooding of the mine would have allowed the centrate as an interim product for final processing at residual uranium and other metals to dissolve and Seelingstädt. Residues from this process as well as the rise from the deposit located in the fourth aquifer to leached rock were moved to the Schüsselgrundhalde the overlying third aquifer and then discharge to the mine dump. Elbe River.

When uranium production was terminated in With this scenario in mind, the option calling for 1990, the mine had produced about 18,000 tonnes of monitored and controlled flooding involving con­ uranium, of that total some 70 per cent by conven­ struction of control drifts and water treatment in an tional mining and 30 per cent by in situ leaching. above ground facility was given preference over all other remedial approaches. Therefore, remedial Remediation goals/concepts emphasis will focus on:

Its location within the Sächsische Schweiz Protected 3 Removal from underground of substances with Landscape Area and its vicinity to the Elbe River make the potential to pollute the incoming groundwa­ the Königstein site stand out among the other reme­ ter (grease, oil, etc.), diation sites of Wismut GmbH. 3 Operation of control drifts aimed at preventing Above ground remediation is characterised by discharge of contaminated water, and allowing the requirement to blend the area affected by mining direct monitoring and sampling of flood water, into the „Sächsische Schweiz“ Protected Landscape Area and to control contaminant release from above 3 Attenuation of sulphuric acid concentration of ground springs and wells. The remedial concept leach solutions, specifies­ in this respect that radioactively contami­ nated facilities and buildings unfit for further use be 3 Removal of easily soluble uranium and other demolished and radioactive areas excavated. In addi­ heavy metals, and tion to contaminated material from ground excava­ tion, water treatment residues are to be moved to the 3 Sealing of mine perforations between the 3rd Schüsselgrund mine dump. and 4th aquifer to minimise water rise into 3rd aquifer during flooding. Clean-up goals for the Schüsselgrund mine dump focus for the most part on the reduction of precipita­ Remediation achievements tion infiltration into groundwater, of radon exhala­ tion and of gamma radiation exposure. To this end, While the slope of the Schüsselgrund mine dump is the mine dump is recontoured and capped. Capping already capped with 1 metre of mineral soil to reduce will be followed by vegetation as the final step to inte­ radon exhalation and infiltration of precipitation as grate the dump in the Protected Landscape Area. well as to promote vegetation, precipitation contin­ 38 4 Remediation sites

ues to infiltrate the mine dump by the uncapped pla­ run-off from reclaimed slope areas for discharge to teau area. Contaminated seepage is intercepted by a the receiving stream. drainage system and piped to the flood water treat­ ment unit. A rainwater retention pond established at The Schüsselgrund mine dump will continue to the toe of the mine dump receives uncontaminated receive any radioactively contaminated material

South North

Shaft 398 Shafts 388 and 390 Dewatering wells North fault Air well no. 5

Aquitard Aquifer no. 1

Aquitard Aquifer no. 2

Aquifer no. 3

S a n d s t o n e

135 m level

Aquitard

Flooding 2010: 102 m NN

94 m level Flooded mine, aquifer no 4

50 m G r a n i t e level

25 m level, north controll drift

Königstein mine, schematic vertical profile, flood level as of December, 2010 (not to scale) 39

Plant area and Schüsselgrund mine dump (2007) Remedial work at Schüsselgrund mine dump (2010) from the clean-up of the Königstein site. In 2009 alka­ contaminated mine water. Investment expenditure line material was tilled into the top layer of the entire for this two-stage unit for uranium removal and water uncapped plateau area. Precipitation is supposed to treatment was in the order of ca. 15 million euros. take up and carry the alkalinity inside the dump and Since coming on-stream in 2000 the plant has treated aid in the neutralization of the dump’s acidic pore 39 million cubic metres contaminated water. water. The final covering of the Schüsselgrund mine dump started in 2010. Impacts due to remedial operations are recorded and documented as part of the environmental moni­ In the meantime, off-site plant areas like the Rott­ toring programme. Environmental surveillance at werndorf ore loading station have been cleaned up. the Königstein site comprises long-term monitoring of flood water and mine dump as potential sources of Establishment of underground control drifts contaminant release and of their impact on ground­ designed to intercept contaminated flood water was water and surface water bodies. Moreover, a flood- finalised in 1994. After experimental flooding con­ related monitoring system was established to moni­ ducted over several years, flooding of the Königstein tor and control the flood process. Monitoring also mine was initiated in 2001. Since then, natural inflow extends to the release of airborne particles. and controlled addition of groundwater have gradu­ ally raised the water level in the mine to ca. 100 me­ Concentration levels of trace elements and urani­ tres a.s.l. um in the flood water have significantly decreased as a result of the multi-year flushing of the sandstone in To continue flood control after mine closure, it the underground mine. Immission measurements was necessary to connect the flooded control drifts conducted in the Elbe River show that there is no which are then functioning as horizontal wells to the environmentally relevant impact on the Elbe due to water treatment plant. To this end, two 300 metres discharge of treated water from the Königstein site. deep wells were drilled in 2009 at a cost totalling about 8 million euros. The flood monitoring network monitors the rise of the groundwater level in the third and fourth aqui­ While the underground mine was prepared for fer, the void subject to flooding, and the groundwater flooding, a water treatment plant was built to treat quality during and after flooding of the Königstein 40 4 Remediation sites

Groundwater sampling at Königstein site

mine. Monitoring emphasis is on areas of zones of Dresden-Gittersee potential flood water rise to the third aquifer as well as on discharge areas of the third and fourth aquifer Initial situation along the northern and western edges of the mine. The Dresden-Gittersee site of Wismut is located with­ Due to the continued shrinking of the volume of in a historic coal mining district where hard coal was open mine workings in recent years, there is a steady mined from 1542 through 1967. After the uranium decrease of radon exhalation from the Königstein content of the coal had been established in 1946, coal mine. There is no record of any significant radiologi­ was also mined for its uranium content from 1947 till cal exposure to the public via the atmospheric path­ 1955. In the 1950s, Wismut temporarily took over way. hard coal mining operations from VEB Steinkohlen­ werk Freital, later renamed as VEB Steinkohlenwerk Outlook “Willi Agatz”. Following complete taking over by Wismut in 1968, the uranium-bearing coal deposit In preparing for further pull-out of the mine, gradual was exclusively mined for uranium. backfilling of pit shaft #390 continues. Sealing of the last remaining ventilation raise #5 is under way and The uranium deposit extends across the mining the open drift in the aquiclude is being backfilled. fields of Gittersee, Bannewitz, and Heidenschanze. According to current planning, pull-out of the mine is Abandoned in 1958, the Heidenschanze mining field to be finalised by mid-2012 after sealing of pit shafts was not included into uranium mining operations #388 and #390. starting in 1968 for economic reasons, but remained hydraulically connected to the other mining fields. The licensing procedure initiated in 2005 for final flooding up to the natural level of groundwater rise is The mined uranium-bearing coal was at first currently suspended. hauled to Freital-Döhlen and Dresden-Coschütz for 41

processing. Afterwards, the ore was transported by rail taminated by the mining of uranium ore as well as to Crossen or Seelingstädt, respectively, for processing. the remediation in situ of the Gittersee and Marien­ schacht mine dumps by contouring and capping with When mining operations were terminated in a multiple layer cover. 1989, about 4 million tonnes of uranium-bearing coal had been mined, creating mine workings of some 2 Proposed work for underground remediation million cubic metres and extending over a surface included the rehabilitation of the mine workings by area of 210 hectares. A considerable portion of the backfilling of pit shafts and controlled flooding of the mine workings has either caved or was closed by set­ mine workings. The flooding conception provided for tlement. From 1949 through 1989 about 3,700 tonnes the flood water to rise within the mine workings and of uranium were produced. be kept at a safe level from where it would discharge via the Tiefer Elbstolln tunnel to the Elbe River. Remediation goals/concepts Preparations for flooding included: Remediation and clean-up work began shortly after mining was terminated in 1990. This work was based 3 Removal from the mine workings of materials on preliminary studies conducted already in 1988 on with the potential to pollute the incoming water, mine workings rehabilitation. Termination of mining and in particular of hydrocarbons, operations was followed by a systematic recording of contaminated areas, investigations of the hydrogeo­ 3 Backfilling and safe plugging of pit shafts, logical regime, of groundwater quality in the vicinity of plant areas and mine dumps as well as the sam­ 3 Extension of the monitoring network between pling of receiving streams. the Gittersee mine and the Tiefer Elbstolln tunnel to monitor flooding, In line with the results and findings of those pre­ liminary activities, the proposed rehabilitation work 3 Rehabilitation of the Tiefer Elbstolln tunnel which called for the demolition and dismantlement of above was built from 1817 to 1837 to dewater the 19th ground facilities and buildings, clean-up of areas con­ century coal mines but had lost a considerable

Plant area Dresden-Gittersee before remediation (1992) 42 4 Remediation sites

Remediated plant area and mine dump at Dresden-Gittersee site (2007)

portion of its hydraulic efficiency by 1.5 metre a mining heritage ensemble. It currently houses the sludge deposition, headquarters of Bergsicherung (Mine safety consult­ ants) Freital. 3 Establishment of an alternative temporary water handling system by sinking a drainage well at The Gittersee mine dump was also rehabilitated each of the Gittersee/Bannewitz and Heiden­ in situ. Its capping with a multiple layer system was schanze mining fields to provide for the case that finalised in 2006. insufficient flood water drainage via the Tiefer Elbstolln tunnel would require the construction Natural discharge of the rising groundwater via of a water adit between the Gittersee mine and the abandoned coal mines towards the Tiefer Elb­ the Tiefer Elbstolln tunnel. stolln tunnel was less than predicted and required. As a result, the water level rose up to 180 metres a.s.l. Remediation achievements This level of flood water rise caused surface damage as well as surface water emergences in residential Except for some minor residual work, remedial work areas of the town of Freital. As a consequence, the performed on the plant area was finalised with the flood level was lowered by discharge via the discharge demolition of buildings and facilities and excavation well provided for such an emergency. The flood water of contaminated ground on an area of approximately level in the Gittersee/Bannewitz mining field is kept 21 hectares. at ca. 115 metres a.s.l. Water discharged at the Gitter­ see/Bannewitz mining field is treated in the water Excavated contaminated ground and demolition treatment plant located on the Gittersee mine dump debris have been incorporated in the Marienschacht and discharged in the Kaitzbach creek. Water treat­ and Gittersee mine dumps. Remediation of the ment residues are incorporated in the Schüsselgrund Marienschacht mine dump including plant area was mine dump at the Königstein site. completed in 1999. Remedial work comprised place­ ment of a multiple layer cover and grass seeding of In order to preclude renewed flood water rise and the entire surface area. The Marienschacht pit and its subsidence risks, the decision was taken in 2005, fol­ Malakoff head frame form an industrial monument. lowing regulatory approval, to develop a horizontal Together with its associated mine dump it constitutes gallery running between the Tiefer Elbstolln tunnel 43

Marienschacht mine dump, Malakoff tower, Dresden-Gittersee site (2009) and the Gittersee/Bannewitz mine over a total dis­ tance of ca. 2,900 metres. Flood water from the Gittersee/Bannewitz and Heidenschanze mining fields is to discharge via this gallery to the Tiefer Elbstolln tunnel and from there to the Elbe River without any risk to the public. Flood levels in the Gittersee mining field will be constantly kept at ca. 120 metres a.s.l. and in the Heidenschanze mining field at ca. 130 metres a.s.l.

Development of what is known as Wismut gallery began in 2007 in Freital-Potschappel at the site of the abandoned Osterberg quarry. From that point, the gallery is being developed to the northwest in the direction of the Tiefer Elbstolln tunnel and to the southeast in the direction of pit shaft #3 of the Gitter­ see mining field located in Freital-Burgk.

Rock anchoring, bolting, meshing, and grouting were required to ensure safety and long-term stability in heavily fissured and water-bearing rock zones. By the end of 2010, development progress was 915 Development work of Wismut-Stolln, Dresden-Gittersee site metres towards northwest and 321 metres towards (2009) southeast. Outlook Pending completion of the Wismut gallery in 2013, the flood water level in the abandoned Dresden- It is a specific feature of the Dresden-Gittersee site Gittersee mine is kept at ca. 115 metres a.s.l. Prior to that there are no waters with radionuclide levels discharge to the receiving stream, pumped flood requiring licensing under radiation protection legis­ waters are treated with lime slurry in order to reduce lation for discharge into receiving streams. Perma­ iron levels. Heavy metals, on the contrary, are only nent safe discharge of waters from the flooded Dres­ present at very low concentration levels and there­ den-Gittersee mine via the Wismut gallery towards fore are not of environmental relevance. the Tiefen Elbstolln tunnel will make pumping, treat­

44 4 Remediation sites

ment and discharge of flood water into the Kaitzbach for uranium in this area in 1945. Investigations began creek redundant. The water treatment plant can in the region of Oberschlema at the site of the therefore be dismantled upon completion of the gal­ Markus-Semmler-Stolln, a drainage gallery built in lery. In addition to mitigating environmental impacts, the 16th century in order to dewater the historic the development of the Wismut gallery will also have Oberschlema und Schneeberg mines. The gallery cost-saving aspects. runs from the portal at the Zwickauer Mulde River along the entire Schlema valley and extends out under Schneeberg right up to Wolfgangmassen. Schlema In 1946, near-surface mining started at numerous Initial situation newly discovered lodes in the Oberschlema area. The subsequent development of the deposit down to a The Schlema site is located in southwest Saxony, depth of 640 metres involved 30 pit shafts as well as immediately north of the town of Aue. At this site, one several adits, blind shafts, and winzes. The Markus- of the world’s largest “hydrothermal” uranium depos­ Semmler-Stolln gallery was defined as 0-metre-level its was mined from 1946 through 1990, with its lodes for surveying purposes. The horizontal development yielding ca. 80,000 tonnes of uranium. Mining opera­ of the Oberschlema deposit comprised a total of 23 tions affected areas within the townships of Ober­ levels. schlema and Niederschlema as well as in the Aue sub­ urb of Alberoda and extended to the boundaries of During the course of mining operations, an the towns of Schneeberg and Hartenstein. extended waste pile landscape emerged at the site of the historic Oberschlema radon spa. Apart from waste Uranium ore mining in the Schneeberg-Schlema- rock dumped right in the town’s centre, a number of Alberoda ore field followed upon mining operations conical waste rock piles disturbed the local scenery. for tin, iron, silver, bismuth, copper, cobalt, and nick­ Mining operations also extended to the Silberbach el which have taken place in this district since the valley and the Hammerberg. In an effort to redress mid-15th century. Since the 19th century, uranium the lack of dumping grounds available in the town was mined as a by-product. This advance knowledge area, a rail track was built to haul waste rock for of uranium occurrence and of the use of radon-laden dumping along the Hammerberg and Schafberg water in the Oberschlema spa launched prospecting slopes. In the end, waste rock dumping was extended

Schlema (1960) 45

Table 5: Waste rock pile remediation at Schlema site Footprint Volume End of Remediation* Waste Rock Pile ha 106 m3 Year Dump pit shaft 38 alt/Lichtloch 9 7 0.54 2007 Dump pit shaft 38 neu/208 26 4.7 2012 Dump pit shaft 13b 5 0.27 2007 Hammerberghalde waste rock pile 43 4.0 2011 Dump pit shaft 66/207 25 4.1 2018 Dump pit shaft 371 67 13.5 2025 Dump pit shaft 310 5 0.57 2024 Dump pit shaft 366/plant areas 186/366/383 42 7.7 2013 Dump pit shaft 208W 2 0.06 2001 Dump pit shaft 8 2 0.06 1998 Dump + plant areas pit shaft 12/259/309 14 1.9 2022 Dump Blue Colour Works/pit shaft 13 1 0.04 2008 Dump + plant area pit shaft 373 1 0.11 2007 Dump pit shaft 382 34 4.2 2018 Dump Großschurf I/plant area timber storage 250 2 0.03 1999 Dump pit shaft 372 2 0.08 2008 Dump 312 14 1.2 2011 Dump 382West 26 3.2 2016 Dump pit shaft 250 5 1.0 1992 * including 5 years post-remediation to the Borbachtal valley located within the boundary Oberschlema with residues being discharged into the of the Wildbach community. newly established settling pond in the Borbach valley. From the mid-1950s, radiometric sorting was con­ By the late 1950s at the latest, the Oberschlema ducted at pit shaft #371 and hydrometallurgical pro­ deposit was exhausted. Abandoned pit shafts were for cessing at the Crossen processing plant. the most part backfilled with waste rock and to some extent subsequently plugged. Surface subsidence as In the1960s during active mining, pilot-scale pro­ well as near-surface mine voids were locally back­ jects were initiated with a view to conducting pur­ filled, but there was no systematic mine rehabilita­ poseful remediation of the waste rock piles involving tion. As mining-induced surface cave-ins and subsid­ contouring and afforestation. This, however, resulted ence continued to occur, larger portions of the only in modest corrections to the waste rock pile land­ Oberschlema town area had to be fenced off and scape. which subsequently degenerated into wasteland. In the end, mining operations extended over an With the discovery of the larger and more fertile area of ca. 22 square kilometres and had created Niederschlema-Alberoda deposit, mining operations underground mine openings on 62 levels with a total shifted to the lower Schlema valley and to the banks mined volume of ca. 41 million cubic metres that had of the Zwickauer Mulde River. Mining in that district been developed by means of more than 54 pit shafts, went down 1,800 metres below the level of the numerous blind shafts, and a couple of adits. Of that Markus-Semmler-Stolln gallery. In the wake of these total, 8 pit shafts including 4 ventilation shafts, and 10 mining operations, large waste rock pile complexes blind shafts were still in operation after mine shut­ were dumped on both sides of the Zwickauer Mulde down. Horizontal headings totalled 4,200 kilometres. River and along the town boundaries. When remedial work started, 176 kilometres of head­ ings on 7 levels were still accessible. Mining waste Physical processing of the mined uranium ore totalling ca. 45 million cubic metres had been dumped was initially conducted in the Blue Colour Factory at on 42 waste rock piles covering an area of 311 hectares. 46 4 Remediation sites

Wismut GmbH has responsibility for the reclamation Above ground remedial action was aimed at restor­ of 19 of these waste rock piles. ing to profitable reuse the areas affected by uranium mining operations. The plant areas associated with the Aue mining unit extended over 111 hectares. Apart from mine pits, In detail, the above ground remediation pro­ mine support and auxiliary units included repair gramme was focussed on the following activities: shops, storage and supply complexes, the radiometric sorting unit, ore loading facilities, and tailings pond 3 Remediation of waste rock piles and preparation in the Borbach valley. Handling of uranium ores had for their gradual return to profitable use on the caused widespread radioactive contamination of basis of agreed reuse concepts, plant areas and technical facilities as well as locally elevated levels of arsenic and heavy metals. 3 Demolition and dismantling of buildings and facilities unfit for future use, and Remediation goals/concepts 3 Rehabilitation of plant areas. The remediation objectives were as follows: In essence, the remediation concept for the waste 3 Removal of technical substances with the poten­ rock piles provided for their rehabilitation in situ tial to pollute incoming groundwater, followed by including regrading for long-term stability as well as mine flooding and adjustment of mine ventilation capping and vegetation. to rising flood water levels, Remediation achievements 3 Erection and operation of water treatment plants to reduce contaminant levels in mine waters prior By the end of 2010, 45 pit shafts had been backfilled, to discharge into receiving streams, and sealed, and plugged to ensure long-term stability. In order to protect the ground surface against subsid­ 3 Protection of ground surface against subsidence ence, 232.000 cubic metres of near-surface mine events by backfilling of near-surface mine voids. voids were backfilled in the Schlema-Alberoda area. A major remedial focus was the safeguarding and back­

Schlema subsidence area, spa park (1960) 47

Bad Schlema spa area (2008) filling in a large subsidence area in Oberschlema, In the immediate vicinity of Oberschlema and in turned into a spa park. Another important task was Alberoda, the waste rock pile landscape is completely the establishment of stable and long-lasting mine recultivated. Remedial work is still underway at the ventilation. For this purpose mine workings on the sites of waste rock piles #309, #310, and #371. At the Markus-Semmler level were upgraded and the venti­ other waste rock piles, substantial remedial work is to lation shaft #382 was equipped with new mine fans. a very large extent finalised. At these sites care, post- remedial maintenance and long-term tasks are per­ Flooding of the mine began as early as 1991. To formed in order to ensure long-term remedial suc­ date, ca. 99 per cent of the floodable mine workings cess. Focus is on grass mowing and grazing, mainte­ are flooded. The residual void of ca. 0.5 million cubic nance of ditches and culverts, and forest tending. metres remaining below the Markus-Semmler level will be used as buffer storage facility to compensate In the vicinity of waste rock piles, remedial pro­ for peak inflow levels or temporary shutdown of the gress is significantly reflected by diminished radon water treatment plant. The plant which was built at a concentrations in ambient air. Many sites have reached cost of 15 million euros has since start-up in 1998 compliance with radiation protection standards. At treated some 13 million cubic metres contaminated some locations work is continuing to further improve mine water. the situation.

Operation of the water treatment plant will per­ Surveying and geomechanical monitoring pro­ manently ensure that no contaminated flood water vides evidence of flooding-induced ground move­ will emerge. The flood water level may be lowered or ments which, however, are negligible in comparison raised as need may be. Residues from the water treat­ to mining-induced movements. ment will be moved to waste rock pile #371 where they are incorporated and covered. Seepage from Outlook waste rock pile #371 is treated in a facility erected in 2009 and then piped to the Zwickauer Mulde River Underground remedial work still to be accomplished just like the treated flood water. will focus on the Markus-Semmler level in the Ober­ schlema mining field where further refurbishing of 48 4 Remediation sites

Waste rock pile #38neu / #208, pit shaft #382 and Borbachtal settling pond, (1992)

drifts is required to complete the establishment of a to reach compliance standards, operation of the stable and long-lasting mine ventilation. What is water treatment plant will have to continue for an more, a deformed section of the Markus-Semmler extended period of time. water-adit which is not safe for operation in the long run will have to be replaced. In its place a new by-pass Focus of waste pile remediation during forthcom­ adit (aka Südumbruch) of 1,200 metres length is to be ing years will be on waste rock complex #371 where developed from 2011 to 2013. integration of contaminated soil and rubble from area rehabilitation and demolition of buildings as As a constant drop of contaminant levels in the well as of immobilised water treatment residues will flood water is to be expected but will take some time continue. Cover building operations will be finalised

Pit shaft #366, waste rock pile #366 (1991) 49

Waste rock pile #38neu /#208, pit shaft#382 and covered Borbachtal settling pond (2010) by 2016 except for the engineered area where immo­ Pöhla bilised residues are to be integrated. Initial situation Final contouring and capping of the remaining remotely located waste rock piles #309 and #310 are The Pöhla site is located in the Western Ore Moun­ to be completed by 2015. Depending on remedial pro­ tains on the border with the Czech Republic. The sur­ gress, follow-up work on the reclaimed areas will roundings of Pöhla contain many traces of historical include care as well as post-remedial and long-term mining; some of them date back to the 17th century. tasks. These works are required to ensure long-term After 1945 Wismut started a number of mining devel­ remedial success. opments in the area. Uranium mining conducted in

Waste rock pile # 366, conclusion of remedial work (2010) 50 4 Remediation sites

the Pöhla area from 1967 through 1990 produced area of ca. 34 hectares. Their volume was about 2 mil­ about 1,200 tonnes of uranium. lion cubic metres.

During prospecting for uranium mineralisation Remediation goals/concepts the Hämmerlein tin deposit and the Tellerhäuser tin- uranium deposit were developed by the Pöhla adit The following works had to be accomplished in order and vertical passageways. Mining operations created to ensure a sustainable reduction of contaminant the spacious mine void of ca. 1 million cubic metres of release from the mine closed in 1990 and to blend the the Pöhla mine. The adit portal was annexed to a vast reclaimed former mining area into the surrounding plant area which included the Luchsbachhalde mine landscape: dump. A radiometric ore sorting unit was erected at this site during the 1980s, but shutdown after trial 3 Removal from underground of technical sub­ operation. As a consequence, the ore mined from the stances with the potential to pollute the incom­ Pöhla-Tellerhäuser deposit was trucked to the sorting ing water, unit at mine shaft #371 of the Aue mining unit. 3 Backfilling of redundant near-surface vertical The smaller, separate Pöhla-Globenstein mine passageways and of adits, except for the main had been developed by prospect shaft #24 sunk as adit, early as 1957. Despite most intense prospecting on three levels no mineable uranium mineralisation was 3 Flooding of the mine until natural overflow detected. In 1989/90, the pit shaft was partly back­ occurs at the level of the main adit, filled to ground level and plugged, and the mine was flooded. 3 Maintenance of the main adit to allow monitor­ ing and discharge of contaminated flood water On balance, the mining field extended over an separately from unpolluted infiltration water on area of about 5.5 square kilometres. Above ground the one hand and to maintain access to mine units and the associated pit openings, buildings, facil­ voids for the storage of residues of the Pöhla ities, and mine dumps covered an area of 60 hectares. water treatment plant, on the other, Of that total, the 4 mine dumps covered a footprint

Plant facilities Pöhla (1991) 51

Luchsbachhalde mine dump and passive-biological water treatment plant (2010)

3 Erection and operation of a water treatment Pöhla mine. A total of ca. 740 cubic metres of residues plant for flood water, and contained in 2,956 drums were moved underground for long-term safe storage using 1,700 cubic metres of 3 Remediation of mine dumps the largest of which concrete. was the Luchsbachhalde dump containing 1.8 million cubic metres of mine waste and covering The scheduled overflow of flood water in 2004 an area of 26 hectares. coincided with the trial operation of a passive biologi­ cal treatment plant which had been built at a cost of Remediation achievements ca. 0.7 million euros. The treatment process includes self-aeration of the feed water followed by an iron All above ground facilities were either dismantled or hydroxide precipitation stage where arsenic is also demolished. The Luchsbachhalde dump was regrad­ re­moved. In a following process stage radium is re­ ed and capped with mineral soil. Construction of for­ moved by stonewort algae (Characeae). The final est roads and drainage ditches as well as landscaping stage of the process chain consists of a series of filters was terminated on and around the Luchsbachhalde designed to adsorptively remove residual arsenic and mine dump in 2008, ending substantial remediation radium by means of reactive materials. During the work in this area. trial operation it has become clear, however, that the biological process stage did not perform as anticipat­ After termination of clean-up and demolition ed. With the process stages of iron hydroxide precipi­ work in the Tellerhäuser area, flooding of the mine tation and filtration water treatment continues to commenced in 1992. Until 2004, the flood water was comply with required standards. The contaminant- kept below overflow level by pumping and piped to laden filter material is immobilised at the Schlema- a water treatment plant built in 1994 at a cost of ca. Alberoda water treatment plant and subsequently 2 million euros where it was treated for its radium, integrated into the engineered cell of waste rock pile arsenic, iron, and temporarily for its uranium levels. #371. Technologically modified and highly automat­ ed, the water treatment plant is to return on stream Treatment residues from the water treatment by 2012. plant were stored in the Hämmerlein­­ section of the 52 4 Remediation sites

Remediated Luchsbachhalde mine dump (2010)

Outlook

Rehabilitation of the Luchsbachhalde mine dump, of the Pöhla plant area and of the Schurf 24 mine dump is finalised. Post-remedial care and environmental monitoring have to be continued at these objects.

Final rehabilitation of the Pöhla mine will only be possible after water treatment is terminated. Given that flood water quality is improving at a very slow rate treatment will required over an extended period of time. 53

5 Stewardship sites

Stewardship site Annaberg-Buchholz, Drei Könige waste rock pile at beginning of clean-up operation (2007)

These areas and facilities used for uranium mining positions, signed an administrative agreement re­ operations by the predecessor Wismut Company had garding remediation of formerly abandoned Wismut been returned for the most part in an unremediated sites in Saxony. The aim is similar to the Wismut Proj­ state to local authorities or private parties in the early ect: mitigation of environmental damage in order to 1960s. For these legacies which are known as formerly restore a wholesome and unimpaired environment abandoned Wismut sites Wismut GmbH has no reme­ for the benefit of the public in the affected former diation obligations under the provisions of the Wismut mining regions and provide impetus to positive re­ Act as these sites were neither property of Wismut gional development and economic revival. Financing GmbH on June 30th, 1990 nor ceded to the company for unlimited and unrestricted use. A survey of these objects was established by the legacy inventory com­ piled by the Federal Office for Radiation Protection on behalf of the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety. This inven­ tory documented a total area of ca. 1,500 square kilo­ metre in Saxony, Saxony-Anhalt, and Thuringia. For Saxony alone, ca. 1,900 individual objects were identi­ fied. This inventory served as the basis for an initial agreement concluded in 2001 between the federal Stewardship site Annaberg-Buchholz, Drei Könige waste rock government and the Free State of Saxony regarding pile, protective wall around remaining conical piles after com­ pletion of remediation (2008) seven priority rehabilitation projects at the sites of Johanngeorgenstadt, Breitenbrunn and their envi­ ronments. For these priority projects the federal gov­ is provided equally by the Federal Government and ernment and the Free State of Saxony provided the Free State of Saxony to the tune of 78 million financing totalling ca. 4.8 million euros. In September euros to terminate the effort by 2012. An advisory 2003, the federal government and the Free State of council on remediation was established to steer and Saxony, without prejudice to their respective legal control the rehabilitation of formerly abandoned 54 5 Stewardship sites

Stewardship site Schneckenstein, pit shaft 241, central shaft and waste rock piles in the background (ca. 1948)

Stewardship site Schneckenstein, waste rock pile #241 after remediation (2010)

Wismut sites. Wismut GmbH is mandated with the implementation of the remedial projects. By the end of 2010, 58 million euros were spent for the remedia­ tion of more than 150 objects located at a large num­ ber of sites in Saxony. A considerable number of reclaimed areas have been restored to local commu­ nities for sustainable reuse. Talks are expected to begin in 2011 on a follow-up to the administrative agreement between the Federal Government and the Free State of Saxony for the period starting in 2013. 55

6 Public relations

Visitors at Open Day, Ronneburg site

Due to decades of a policy of secrecy followed by al projects were presented on the occasion of the Wismut, in 1990/91 the newly established Wismut 2000 World Exposition EXPO 2000 and the National GmbH and their activities were confronted with Horticultural Exhibition held in 2007 in Ronneburg. strong mistrust and reservations on behalf of not only the public and the media but also the nascent regula­ Since 1991, more than 1.5 million visitors from tory authorities. At that time, Wismut was almost Germany and abroad were welcomed to remedial daily in the news, mostly providing unfavourable sites in Saxony and Thuringia. headlines. A particular form of paying tribute to remedia­ Purposeful and transparent information policy tion achievements and regional development was the and meaningful outreach work were therefore high Saxon State Award for Building Culture 2008 award­ on the agenda for the Wismut GmbH. The change of ed jointly to Wismut GmbH and the spa town of Bad image came as a result of numerous confidence- Schlema for their joint submission „From Death building measures, but first and foremost of success­ Valley to Spa Town“. ful remediation that was visible from the outside, conducted by the federally-owned Wismut GmbH.

Nowadays Wismut GmbH presents itself by numerous public outreach activities as an efficient remedial company. Local communities, districts, public authorities, technical experts and environmental groups were involved in the development of remedial concepts, the identification of remediation goals and proposals for the reuse of reclaimed properties. Information centres were established at remediation sites in Saxony and Thuringia. Wismut GmbH keeps the public informed about remedia­ tion progress by the press, online, “Open Days” at the sites and presents itself at national and international symposia. A number of Wismut’s outstanding remedi­ Environmental reports of Wismut GmbH 56

7 Arts collection

Evidence of the vast artistic and cultural activities of About half of the works, which were for the most SDAG, some 4,100 works of art (paintings, drawings, part commissioned, are thematically related to min­ graphic art among others) dedicated by 450 artists are ing. Their focus is on underground scenery, mine owned by Wismut GmbH. landscapes, pit shafts and mine buildings. There are also a great number of miner portraits and group pic­ Artists working for SDAG Wismut came notably tures representing four decades of uranium ore min­ from the Academy of Visual Arts Leipzig, which estab­ ing. Others works include still lives, landscapes, nude lished its reputation as the “Leipziger Schule”, and the studies, everyday scenes, animal representations, or Dresden University of Art. In addition, the collection literarily inspired paintings. comprises works by artists from art colleges in Halle, Berlin, and Weimar. It also includes many works by Ranking as the largest and most important of amateur artists working in visual art clubs at Wismut. GDR corporate collections, the Wismut GmbH arts Other contributions were provided by artists from collection will continue to be presented to the public. Armenia, Hungary, Bulgaria, Poland, and Russia.

Nikola Kiriliev: Blackbirds over mine dumps, 1989 57

8 Documentation on Wismut corporate history

In 2008, a project was launched to comprehensively To this end, a project team has been formed under document and depict more than 40 years of uranium the overall responsibility of the Chemnitz University ore mining by Wismut in Saxony and Thuringia as of Technology. Financing is ensured by contributions well as rehabilitation results achieved after 1990 by from the Ministry of Economics and Technology, the Wismut GmbH. Scientific studies and documentation Chemnitz University of Technology, the Gerda Henkel will also include the subject areas of politics, econom­ Foundation, the Friedrich Ebert Foundation, the ics, environment, and social affairs. International Munich-based Institute of Contem­porary History, and comparative studies have been proposed, with the Wismut GmbH. Study volumes documenting Wismut aim of providing benchmarks for the classification corporate history will be published in summer 2011. and evaluation of Wismut corporate history, particu­ This publication will constitute a major work of refer­ larly with regard to business regime, levels of sophis­ ence regarding Wismut corporate history. tication of mining engineering, environmental con­ cerns and radiological protection, safety standards, economic viability, and employee social benefits.

May day rally in the 1960s

Order no. 155, Soviet Military Administration, 1945 58

9 Summary and outlook

Since uranium ore mining was terminated and reme­ 2020. Thereafter, some objects will require post-reme­ dial operations started 20 years ago, remedial results dial care, and long-term tasks will have to be per­ achieved by Wismut GmbH in rehabilitating the lega­ formed at nearly all reclaimed sites. This includes in cies of former uranium ore mining operations are particular the interception and treatment of flood clearly visible at all sites in Saxony and Thuringia. water and seepage, maintenance of covered areas of More than 80 per cent of the physical work had been waste rock piles and tailings management areas, the finalised by 2010. Environmental impacts in the operation of a vast environmental monitoring system affected areas have been significantly reduced by the as well as mine inspection tasks. The time frame remedial efforts. required for these efforts cannot be specified at the present time. Today, the rehabilitated areas once again have become home to a multitude of animals and plants. This brochure provides a general overview of the A bio-monitoring programme is helping Wismut to remediation work performed by Wismut GmbH, keep track of the return of the indigenous fauna and including its mission, goals, and achievements. In the flora. annexed flyer, tables and graphs provide figures on key processes and developments of Wismut GmbH. The work completed so far has provided a sound For more complete information concerning the basis for the accomplishment of future tasks. The fed­ Wismut Project, please log onto the Wismut GmbH eral government will continue to fund the effort. website at (www.wismut.de) or consult the extensive According to current levels of knowledge in 2011, sub­ literature available on this subject. stantial remediation work will be completed after

Rose chafer (Cetonia aurata) on large pink (Dianthus superbus) 59

Reclaimed waste rock pile landscape Schlema site (2010)

The rehabilitation and reuse of former mining areas establish key preconditions for economic devel­ opment and job creation. Continued remediation at formerly abandoned Wismut sites will provide local communities with new possibilities for the sustaina­ ble use of reclaimed mine land. 60

This brochure is published free of charge as part of the public relations work of the Federal Ministry of Economics and Technology. It is distributed free of charge and is not intended for sale. It may not be used by political parties, candidates or electoral assistants for purposes of election campaigning. In particular, the distribution of this publi­ cation at campaign events or at information stands run by political parties is prohibited, and political party-related information or advertising shall not be inserted in, printed on, or affixed to this publication. The distribution of this publication to third parties for purposes of election campaigning is likewise prohibited. Irrespective of when, how and in what quantity this publication reaches the recipient, it shall not be distributed or used – even outside the context of election campaigns – in any manner that suggests bias on the part of the Federal Government in favour of specific political groupings.