Guidelines for mine closure activities and calculation an periodic adjustment of financial guarantees.
Date: 2021-03-22
Institutions: Directorate-General for Environment
Subjects: EU Member State, EU financial instrument, cessation of trading, directive (EU), environmental impact, health risk, investment protection, mining extraction, report, scientific calculation, technical standard, waste management

Guidelines for Mine Closure 
Activities and Calculation and 
Periodic Adjustment of Financial 
Guarantees

March 2021 

Study on the elaboration of guidance on best practices 
for the calculation and the periodic adjustment of the 
financial guarantee for extractive waste facilities 
07.201/2018/793585/ETU/ENV.B.3 

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PDF        ISBN 978-92-76-32067-8        doi:10.2779/350770        KH-09-21-049-EN-N

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Study on the elaboration of guidance on best practices 
for the calculation and the periodic adjustment of the 
financial guarantee for extractive waste facilities 
07.201/2018/793585/ETU/ENV.B.3 

ABSTRACT 

The Directive 2006/21/EC3 on the management of waste from the extractive industries 
("the  Directive"  or "EWD") provides minimum requirements, procedures and guidance 
to prevent or reduce as far as possible any adverse effects on the environment and any 
resulting  risks  on  human  health  from  the  management  of  extractive  waste.  The  Di-
rective requires the competent authority to demand a financial guarantee (FG), prior to 
commencement of any operations involving the accumulation of extractive waste. 

In this context, the EWD requires the Member States (MS) to ensure that the operator 
draws up an Extractive Waste Management Plan (EWMP). The EWMP must include a 
closure plan, including site rehabilitation, after-closure procedures and monitoring. For 
waste  facilities  that  require  a  permit,  the  EWMP  is  part  of  the  permit  application.  The 
FG is to be established in accordance with procedures to be decided by the MS. The 
guarantee  is  lodged  at  the  pre-operational  phase  and  based  on  anticipated  closure 
measures and their implementation cost, e.g. as specified in the EWMP. Since the op-
erational  phase  of  a  mine  might  last  for  several  decades,  there  is  a  degree  of  uncer-
tainty associated with the FG. The EWD addresses this issue by requiring a review of 
the EWMP every 5 years and the FG periodic adjustment in accordance with any reha-
bilitation work needed to be carried out as described in the EWMP. For the closure and 
after-closure phase, the EWD requires MS to ensure that the operator requests an au-
thorisation to start the closure procedure. This request is based on the latest periodic 
review of the EWMP taking into account the actual environmental impact of the waste 
facility and elaborates in detail the closure tasks and programmes including expected 
costs. Some MS require a separate closure plan. 

The Commission has adopted a Decision on technical guidelines for the FG establish-
ment in accordance with the EWD. Some MS suggested to provide additional technical 
guidance for the implementation of the FG provisions. The present guideline document 
(GD) aims to support the EWD implementation by elaborating technical guidance for 

• Collection and description of the Closure Best Practices by Mining Typology

• FG  calculation  prior  to  the  commencement  of  waste  deposit,  and  FG  periodic

adjustment;

• Elaboration of updated closure plans taking into account the environmental im-

pact of the operations; and

• Approaches  for  determining  the  cost  of  the  respective  activities  to  implement

the closure plan.

As specified in the Terms of Reference for this project, the scope of the GD goes be-
yond the EWD  requirements for the closure of extractive waste facilities and includes 
FG approaches for wider aspects of mine closure (e.g. brownfields, wastes not directly 
resulting  from  mineral  extraction,  decommissioning  of  infrastructures  used  for  mining 
but not for waste management, and closure of cavities that might cause risk to human 
and environment). The GD focuses on FG for decommissioning, closure, rehabilitation 
and  after-closure  of  mine  sites,  related  infrastructure  and  associated  waste  facilities 
(“closure  of  a  mine  site”).  This  includes  all  mines  associated  with  Category  A  waste 
facilities (e.g. TMFs and heaps) for which FG are required by the EWD as well as other 

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Study on the elaboration of guidance on best practices 
for the calculation and the periodic adjustment of the 
financial guarantee for extractive waste facilities 
07.201/2018/793585/ETU/ENV.B.3 

mining objects for which the competent authorities might require further FG to ensure 
public closure and post-closure safety.  

The  GD  considers  all  mining  typologies,  e.g.  aggregates,  ores,  energy,  and  industrial 
minerals, with all types of extraction approaches (underground, opencast, and borehole 
mining). The GD comprises two main topics: 

•

•

description of the technical solutions for mine closure (sections 1 – 4), and

documentation  of  cost  profiles  and  cost-relevant  activities  for  the  technical
measures of those solutions (section 5).

The GD for the technical solutions is structured in the following sections: 

• Part A - Provisions on the Establishment of Financial Guarantees: this section
deals  with  the  FG  role  and  purpose,  the  financial  options  and  instruments,  as
well as their applicability and routines for establishment.

• Part  B  -  General  Provisions  on  Best  Practices  for  Closure,  Rehabilitation  and
After-closure  Design:  this  section  deals  with  the  general  approach  to  closure
design options, the permitting and implementation requirements and quality as-
surance of implementation.

• Part  C  -  Overview  on  Closure  Best  Practices  by  Mining  Typology:  this  section
deals  with  the  mining  typologies,  and  the  specifics  and  challenges  of  aggre-
gates,  industrial,  and  energy  minerals  as  well  as  ore  mining.  The  section  is
supported by mine closure show cases.

• Part D - Cost Profile, Cost-Relevant Activities and Unit Cost: Cost profiles and
unit cost were obtained from about 30 closure plans and related Bills of Quanti-
ties (BoQs) from implemented mine closure activities of the last 20 years, main-
ly  from  Northern,  Central  and  Eastern  Europe.  The  data  were  complemented
with  information  from  comparable  rehabilitation  works,  for  instance  landfill  clo-
sure and aligned with information on unit cost provided by the MS.

The considered closure activities concern tailings management facilities (TMF) rehabili-
tation as well as other mining facilities closure, like cavities, mine seepage water out-
lets and mine waste disposal sites. Through these shaft and mine waste heap closure 
activities  will  be  ensured  to  prevent  a  future  release  of  waste  materials  into  the  envi-
ronment. It is to be noted that the GD does not refer to unforeseen liabilities according 
to Art. 6 EWD. 

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financial guarantee for extractive waste facilities 
07.201/2018/793585/ETU/ENV.B.3 

CONTENT 

1. 

Introduction ............................................................................................................ 16 

1.1  General Introduction: Objective of the GD ...................................................... 16 
1.2  Structure of the GD ......................................................................................... 17 
1.3  Glossary / Key Terminology ............................................................................ 18 
1.4  Legal Framework ............................................................................................. 24 
1.4.1 
European Union Legislation ................................................................... 24 
1.4.2  National Legislation ................................................................................ 25 
Licensing / Permitting Conditions ........................................................... 32 
1.4.3 
Institutional Framework .......................................................................... 34 
1.4.4 

2.  Part A: Principles and Purpose of Financial Guarantees .................................. 35 

2.1  Overview of the Financial Provision Determination Process ........................... 35 
2.1.1  General Approach .................................................................................. 39 
2.1.2  Overview on Financial Provision Instruments ........................................ 40 
2.1.3 
Time Schedule for Establishing the Financial Guarantee ...................... 44 
2.1.4  Coverage of the Financial Guarantee .................................................... 44 
2.1.5 
Approach to Financial and Economic Analysis ...................................... 45 
2.1.6  Cost – Benefit - Analysis ........................................................................ 48 
2.1.7 
Structure of Costing ............................................................................... 48 
2.1.8  Costing: Investment and Maintenance Cost .......................................... 50 
2.1.9  Costing: Engineering and Supervision Cost ........................................... 51 
2.1.10  Plausible Worst Case Scenario .............................................................. 53 
2.1.11  Content of Technical Design .................................................................. 56 
2.1.12  Bills of Quantities ................................................................................... 58 
2.1.13  Cost Profile and cost-relevant activities ................................................. 58 
2.1.14  Periodic Adjustment of the Financial Guarantee .................................... 58 
2.1.15  Quality Management due to ISO 9001:2015 .......................................... 59 
2.2  Financial Guarantee Implementation .............................................................. 60 
2.3  Review and Release of the Financial Guarantee ............................................ 60 

3.  Part B: Best Practices for Closure, Rehabilitation and After-closure Design . 62 
3.1  Combined Closure, Rehabilitation and After-closure Plans ............................ 62 
3.2  Definition of the Rehabilitation Scope and Resulting Closure Steps ............... 62 
3.3  Definition of After-closure Options ................................................................... 64 
3.4  Design of a Closure Plan ................................................................................. 66 
3.4.1  General Approach .................................................................................. 66 
3.4.2 
Structure of a Closure Plan – Design for Closure .................................. 67 
Site Investigation and Extractive Waste Characterization ...................... 70 
3.4.3 
3.4.4  Option Analysis ...................................................................................... 71 
3.4.5  Closure Tasks ........................................................................................ 73 
3.4.6  Closure Plan Costing ............................................................................. 73 

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financial guarantee for extractive waste facilities 
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3.4.7  Criteria for Successful Closure ............................................................... 74 
Accompanying Documents .................................................................... 75 
3.4.8 
3.4.9  Closure Plan Validation and Audit .......................................................... 75 
3.4.10  Environmental Impact Assessment ........................................................ 75 
3.4.11  Environmental Management Plan .......................................................... 80 
3.4.12  Occupational Health and Safety Plan .................................................... 80 
3.5  Design of an After-closure Plan ....................................................................... 80 
3.5.1 
Approach to After-closure ...................................................................... 80 
After-closure Measures and Activities .................................................... 81 
3.5.2 
3.5.3  Restoration and After-closure Costing ................................................... 81 
3.5.4 
Environmental Monitoring Plan .............................................................. 82 
3.5.5  Rehabilitation and After-closure Plan Review ........................................ 82 

4.  Part C: Overview on Closure Best Practices by Mining Typology .................... 83 

4.1  Best Practices Overview ................................................................................. 83 
4.2  BREF for Extractive Waste Management ........................................................ 83 
4.3  Mining Typology .............................................................................................. 84 
4.3.1 
Aggregates ............................................................................................. 85 
4.3.2  Ores ....................................................................................................... 87 
Energy Minerals ..................................................................................... 89 
4.3.3 
Industrial Minerals .................................................................................. 94 
4.3.4 
4.4  General Overview on Closure Activities .......................................................... 97 
4.5  Closure of Aggregate Mining Sites ................................................................ 100 
4.5.1  Overview .............................................................................................. 100 
4.5.2 
Particular Challenges at Aggregate Mining Sites ................................. 100 
Earthworks ........................................................................................... 101 
4.5.3 
4.5.4  Water Management .............................................................................. 101 
Ensuring Long Term Geotechnical Stability ......................................... 102 
4.5.5 
Ensuring Long Term Environmental Safety ......................................... 102 
4.5.6 
After-closure: Revegetation, Flooding, Nature Protection .................... 102 
4.5.7 
4.6  Closure of Ore Mining Sites .......................................................................... 104 
4.6.1  Overview .............................................................................................. 104 
4.6.2 
Particular Challenges at Ore Mining Sites ........................................... 105 
4.6.3  Closure of Open Cast Mines ................................................................ 108 
4.6.4  Closure of Underground Mines ............................................................ 110 
4.6.5  Management of Solid/liquid Control of Extractive Waste ..................... 118 
4.6.6 
Extractive Waste Stabilisation .............................................................. 118 
4.6.7  Compaction, Consolidation and Deposition of Extractive Waste ......... 119 
Prevention or Minimisation of Pollutant Leaching ................................ 119 
4.6.8 
4.6.9 
Prevention or Minimisation of Acid Rock Drainage (ARD) ................... 119 
4.6.10  Prevention or Minimisation of Self-ignition of Extractive Waste ........... 120 
4.6.11  Reduction of Dangerous Substances in Extractive Waste ................... 120 
4.6.12  Minimisation of Groundwater Status Deterioration and Soil Pollution .. 120 
4.6.13  Closure of Tailings Management Facilities .......................................... 121 
4.6.14  Closure and Covering of Waste Rock Heaps ....................................... 124 
4.6.15  Groundwater and Soil Pollution Remediation ...................................... 125 

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financial guarantee for extractive waste facilities 
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4.6.16  Surface Water Pollution Remediation .................................................. 126 
4.6.17  Prevention or Minimisation of Dusting of Extractive Waste .................. 127 
4.6.18  Decommissioning of Buildings and Processing Plant Areas ................ 127 
4.6.19  Water Management and Treatment ..................................................... 128 
4.6.20  Ensuring Long Term Geotechnical Stability ......................................... 129 
4.6.21  Ensuring Long Term Environmental Safety ......................................... 129 
4.7  Closure of Energy Minerals Mining Sites ...................................................... 129 
4.7.1  Overview .............................................................................................. 129 
Particular Challenges at Energy Minerals Mining Sites ....................... 130 
4.7.2 
4.7.3  Closure of Open Cast Mines ................................................................ 131 
4.7.4  Closure of Underground Mines ............................................................ 134 
4.7.5  Water Management .............................................................................. 134 
Ensuring Long Term Geotechnical Stability ......................................... 137 
4.7.6 
4.7.7 
Ensuring Long Term Environmental Safety ......................................... 140 
4.7.8  Closure of Hydrocarbon Boreholes ...................................................... 141 
4.8  Closure of Industrial Minerals Mining Sites ................................................... 143 
4.8.1  Overview .............................................................................................. 143 
Particular Challenges at Industrial Minerals Mining Sites .................... 144 
4.8.2 
Earthworks ........................................................................................... 145 
4.8.3 
4.8.4  Water Management .............................................................................. 145 
Ensuring Long Term Geotechnical Stability ......................................... 146 
4.8.5 
Ensuring Long Term Environmental Safety ......................................... 147 
4.8.6 
4.9  Mine Closure Show Cases ............................................................................ 149 
4.9.1 
Aggregates Mining ............................................................................... 149 
4.9.2  Ore Mining ............................................................................................ 151 
Energy Minerals Mining ........................................................................ 157 
4.9.3 
Industrial Minerals Mining .................................................................... 161 
4.9.4 

5.  Part D: Cost Profile, Cost-Relevant Activities and Unit Cost .......................... 165 

5.1  Data Base and Approach .............................................................................. 165 
5.2  Cost Profiles of Engineering Works ............................................................... 165 
5.2.1  Cost estimation, Bills of Quantity and Procurement rules .................... 165 
Site Investigation .................................................................................. 167 
5.2.2 
Feasibility Study ................................................................................... 167 
5.2.3 
Technical Design .................................................................................. 167 
5.2.4 
Supervision .......................................................................................... 168 
5.2.5 
5.2.6  Occupational Health and Safety ........................................................... 168 
Environmental Monitoring .................................................................... 169 
5.2.7 
Environmental Reporting ...................................................................... 169 
5.2.8 
5.3  Cost Profile of Technical Works .................................................................... 169 
5.3.1 
Site Preparation ................................................................................... 170 
5.3.2 
Earthworks ........................................................................................... 171 
Fencing and Drainage .......................................................................... 172 
5.3.3 
5.3.4  Demolition / Decommissioning ............................................................. 173 
5.3.5 
Placing Back Extractive Waste into Excavation Voids ......................... 173 
5.3.6  Relocation ............................................................................................ 174 

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financial guarantee for extractive waste facilities 
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5.3.7  Groundwater Protection through Cut-off Wall ...................................... 174 
Shaft and Adit Closure ......................................................................... 175 
5.3.8 
5.3.9 
TMF Dewatering/Stabilisation and Covering ........................................ 176 
5.3.10  Application of Surface Sealing ............................................................. 177 
5.3.11  Reclamation / Revegetation ................................................................. 179 
5.3.12  Flooding ............................................................................................... 180 
5.3.13  Waste Disposal .................................................................................... 181 
5.4  Cost-relevant Activities for the FG Calculation and Periodic Adjustment ...... 182 
Site Investigation .................................................................................. 183 
5.4.1 
Site preparation and quality management ........................................... 185 
5.4.2 
Earthworks ........................................................................................... 187 
5.4.3 
Fencing and Drainage .......................................................................... 189 
5.4.4 
5.4.5  Demolition / Decommissioning ............................................................. 190 
5.4.6 
Filling .................................................................................................... 192 
5.4.7  Relocation ............................................................................................ 193 
5.4.8  Hydraulic and Geochemical Water Protection Options ........................ 193 
5.4.9 
Shaft and adit closure .......................................................................... 194 
5.4.10  TMF Dewatering and Closure .............................................................. 195 
5.4.11  Application of Surface Sealing ............................................................. 197 
5.4.12  Reclamation / Revegetation ................................................................. 199 
5.4.13  Flooding and Water Treatment ............................................................ 200 
5.4.14  Water treatment ................................................................................... 201 
5.4.15  Waste disposal ..................................................................................... 201 

6.  References ........................................................................................................... 203 

ANNEXES 

ANNEX 1: Correlation between the annex of the EIA Directive with the formalities of the 
codes of the Statistical Classification of Economic Activities in the European Communi-
ty (commonly referred to as NACE). 

ANNEX 2: Sample of a report structure for Environmental Impact Assessment of mine 
closure projects. 

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financial guarantee for extractive waste facilities 
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TABLES:  

Table 1: Mine Reclamation Financial Provision Instruments (MonTec, 2008; amended 
by the authors)...................................................................................................... 42 
Table  2:  Closure  Guarantee  Factors  (after  Legislative  Audit  Division,  1997;  Mota  de 
Lima, 2003; Cheng & Skousen, 2017; amended by the authors) ......................... 49 
Table 3: Cost estimation levels during the design process .......................................... 52 
Table 4: Definitions of sensitivity levels of receptors .................................................... 78 
Table 5: Definitions of magnitude levels of impacts ..................................................... 79 
Table 6: Numerical ranking and verbal category of impact significance ...................... 79 
Table 7: Closure components applicable for type of mine ........................................... 98 
Table  8:  Some  inorganic  reagents  and  their  primary  functions  in  ore  processing 
(Pearse, 2005) .................................................................................................... 106 
Table  9:  Typing  of  acidic  open-cast  ponds  according  to  the  origin  of  the  acidification 
(Nixdorf et al., 2000) ........................................................................................... 141 
Table  10:  Some  inorganic  reagents  and  their  primary  functions  in  industrial  mineral 
processing (Pearse, 2005) ................................................................................. 145 
Table 11: Sample of cost calculation - shafts and adits in Elesnitsa region (in EUR)  156 
Table 12: Unit price range for site investigations ....................................................... 183 
Table 13: Unit price range for site preparation and quality management ................... 185 
Table 14: Price range for earth works. ....................................................................... 188 
Table 15: Unit price range for fencing ........................................................................ 189 
Table 16: Unit price range for drainage ...................................................................... 190 
Table 17: Unit price range for demolition / decommissioning ..................................... 191 
Table 18: Unit price range for filling ............................................................................ 192 
Table 19: Unit price range for hydraulic and geochemical water protection options .. 193 
Table 20: Unit price range for shaft closure ............................................................... 195 
Table 21: Unit price range for adit closure ................................................................. 195 
Table 22: Unit price range for TMF dewatering and closure ...................................... 196 
Table 23: Unit price range for the application of surface sealing ............................... 197 
Table 24: Unit price range for reclamation / revegetation .......................................... 200 
Table 25: Unit price range for flooding and water treatment ...................................... 200 
Table 26: European Electricity prices (source: https://strom-report.de/electricity-prices-
europe/) .............................................................................................................. 201 
Table 27: Unit price range for waste disposal ............................................................ 202 

FIGURES:  

Figure 1: Exemplified scheme of mine design and mining process. Black words indicate 
activities  related  to  mine  preparation  and  operation,  blue  words  indicate  water-
related flows and activities, words in brown colour refer to waste-related flows or 
activities (Schneider & Wolkersdorfer, 2021) ....................................................... 16 
Figure 2: Exemplified scheme of a mine balance sheet for environmental rehabilitation 
(Tambo& Theobald, 2018) .................................................................................... 35 
Figure 3: Approach to defining the need for and scope of financial provisions (Bradley 
et al. 2017) ........................................................................................................... 36 
Figure  4:  General  approach  to  assessing  and  costing  environmental  liabilities 
(Environmental Protection Agency of Ireland, 2014) ............................................ 37 
Figure 5: Approach to financial deposits for unforeseen / foreseen liabilities (Bradley et 
al. 2017) ............................................................................................................... 37 
Figure 6: Flow sheet of the principal steps to calculate a FG (MonTec, 2008) ............ 39 
Figure 7: Categories of FG instruments and typical examples (MonTec, 2008) .......... 41 

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financial guarantee for extractive waste facilities 
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Figure  8:  Approach  to  Financial  Analysis  (Legend:  CAPEX:  Capital  Expenditure, 
OPEX: Operational Expenditure) .......................................................................... 47 
Figure 9: Approach to Economic Analysis .................................................................... 48 
Figure 10: Risk Evaluation Matrix according to Nohl & Thiemecke (1988) .................. 54 
Figure 11: Potential TMF failure mechanisms (ATV-DVWK-M 503) ............................ 55 
Figure 12: Simplified sample of a BoQ ......................................................................... 58 
Figure 13: After-closure options in practice .................................................................. 65 
Figure  14:  Integrating  stages  of  mining  and  mine  closure  plan  (Department  of  Mines 
and Petroleum at the Environmental Protection Agency Australia, 2015) ............ 66 
Figure 15: Closure cost estimate types, Legend: LoA - Life of asset (ICMM, 2019) .... 73 
Figure  16:  Overview  on  the  existing  environmental  assessment  approaches  with 
respect to mining .................................................................................................. 75 
Figure  17:  Flow  chart  illustrating  the  EIA  process  (Source:  European  Commission 
Scoping Guidance, 2017) ..................................................................................... 76 
Figure  18:  Influence  and  impact  by  mining  phase.  Analysis  of  potential  impact 
measures that can be taken to offset impact (Hofsteenge et. al, 2017) ............... 77 
Figure 19: Basic illustration of a sand and gravel opencast mine ................................ 86 
Figure 20: View of an aggregates mine (left); aggregates processing plant (right) ...... 86 
Figure 21: Example of a sand dredging facility ............................................................ 87 
Figure  22:  Relation  between  technologies  and  requirements  for  effective  deposit 
utilization .............................................................................................................. 88 
Figure 23: Copper open cast mine in Andalusia, Spain ............................................... 88 
Figure 24: Sample of an overall planning model for underground mining .................... 89 
Figure  25:  Reservoir  formations  of  oil  and  gas  deposits  (left),  oil  and  gas  production 
facilities (right) (Devold, 2013) .............................................................................. 90 
Figure 26:  Example of natural gas extraction by fracking (source: U.S. EPA) ............ 91 
Figure 27:  Scheme of oil and gas extraction (source: MagentaGreen, CC BY-SA 4.0)
 ............................................................................................................................. 91 
Figure 28: Open cast lignite mining in Eastern Germany ............................................. 92 
Figure  29:  Principle  of  open  cast  mining  (Tudeshki  &  Pielow,  2018,  translated  from 
German) ............................................................................................................... 92 
Figure 30:  Uranium mining in Romania: open cast (left, figure source: Dima 2016), and 
underground (right) ............................................................................................... 93 
Figure 31: Salt exploration ........................................................................................... 95 
Figure 32: Surface stockpiling of potash residues........................................................ 95 
Figure 33: Principle of brine extraction by salt leaching (Warren, 2016) ...................... 96 
Figure 34: Kaolin extraction (figure source: German Federal Institute for Geosciences 
and Raw Materials) ............................................................................................... 97 
Figure  35:  Flooding  of  an  aggregate  quarry  in  Sweden  (left);  closed  dry  aggregate 
mining site, included in infrastructural landscape in Germany (right) ................. 101 
Figure  36:  Typical  Drainage  Plan  for  water  management  across  a  quarry  (source: 
Department of Economic Development, Jobs, Transport and Resources. Code of 
Practice  for  Small  Quarries,  2010;  Adapted  from  Quarry  Code  of  Practice, 
Department  of  Environment  and  Primary  Industries  Water  and  Environment, 
Tasmania 1999).................................................................................................. 102 
Figure  37:  Potential  habitats  in  a)  in  gravel,  sand,  clay  and  clay  pits  (left),  and  b) 
quarries (right) (Trautner & Bruns 1988, modified) ............................................. 103 
Figure 38: Impressions of TMFs in Romania ............................................................. 107 
Figure 39: Impressions of Acid Mine Drainage in Spain ............................................ 107 
Figure 40: Conceptual zonation of a filled open pit (Chapman et al. 1998) (left); open pit 
Lichtenberg, Germany (2004), filled with reactive zones (right) ......................... 109 
Figure 41: Sample of a flooded copper mine in Bulgaria (left); water diversion channel 
upstream the mine (right) ................................................................................... 109 

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Figure  42:  Engineering  demands  for  selecting  materials  for  filling  (Zhang  et  al.  2019)
 ........................................................................................................................... 110 
Figure 43: Mine flooding scheme of the Schlema-Alberoda site, Germany (Schneider et 
al. 2005) ............................................................................................................. 112 
Figure  44:  Sample  of  shafts  (left);  adits  (centre)  and  sinkholes  (right)  before 
rehabilitation ....................................................................................................... 113 
Figure 45: Shaft closure: a) full filling: cohesive filling column (left); b) full filling: coarse 
rock filling column combined with cohesive filling column section (centre), and c) 
partial filling: sealing and coarse rock filling column combined with cohesive filling 
column section (right) ......................................................................................... 114 
Figure 46: Shaft mouth sealing with reinforced concrete plate (left); shaft sealing with 
concrete shear plug (right) ................................................................................. 116 
Figure 47: Adit sealing with a) brick wall and filling with crushed or waste rock (left), b) 
with fluid concrete (centre), and c) blasting or pouring with waste rock or crushed 
roc. ..................................................................................................................... 117 
Figure  48:  Adit  or  shaft  mouth  closure  with  brick  wall  and  drainage  pipe  with  siphon 
(left); adit or shaft mouth closure with fluid concrete and drainage pipe with siphon 
(right) .................................................................................................................. 117 
Figure  49:  Sinkhole  sealing  with  concrete  plug  close  to  the  surface  (left);  filling  with 
waste rock (right) ................................................................................................ 118 
Figure 50: Typical TMF to be closed; sample of a copper mining site in Bulgaria ..... 122 
Figure  51:  Overview  on  active  tailings  pond  (left);    tailings  pond  under  forced 
consolidation  through  subaquatic  fill  of  extractive  waste  through  hopper  barge 
(right) .................................................................................................................. 123 
Figure  52:  Application  of  vertical  drains  through  drilling  (left);  TMF  stabilisation:       
geogrid, underlain by geofabric and drain mats (right) ....................................... 123 
Figure  53:  Mineral  sealing  layer  on  waste  rock  heaps  (figure  source:  Wismut  GmbH, 
left) and a reactive horizontal barriers (right, Schneider et al. 2002) .................. 125 
Figure 54: Typical mining facilities structures to be demolished ................................ 128 
Figure  55:  Open  cast  lignite  mining:  in  operation  (left);  in  closure  through  open  pit 
flooding (right) .................................................................................................... 130 
Figure  56:  Main  reclamation  steps  steps  of  open  cast  energy  minerals  mining  sites 
according to Tudeshki & Pielow (2018), amended and modified by the authors 132 
Figure  57:  Activities  in  terms  of  mass  movement  in  open  cast  lignite  mine  closure 
(Tudeshki & Pielow, 2018).................................................................................. 132 
Figure 58: Activities in terms of embankment and soil stabilisation in open cast lignite 
mine closure (Tudeshki & Pielow, 2018; amended by the authors) ................... 132 
Figure 59: Activities in terms of embankment and soil stabilisation in open cast lignite 
mine closure (Tudeshki & Pielow, 2018; amended by the authors) ................... 133 
Figure  60:  Activities  in  terms  of  water  management  measures  including  open  pit 
landscape restoration (Tudeshki & Pielow, 2018; amended by the authors) ..... 133 
Figure 61: Activities in terms of repair of mining damage (Tudeshki & Pielow, 2018) 133 
Figure  62:  Water  management    practices:  flooding  of  a  former  open  cast  lignite  mine 
(above left), construction of water diversion channels (above right), construction of 
water level regulation facilities (down left), mine water management, water is kept 
through a retaining wall (down right) .................................................................. 135 
Figure 63: Water management practices: groundwater retention wall (left); sealing wall 
cutter for construction of a groundwater retention wall (right) ............................ 136 
Figure  64:  Water  management  practices:  groundwater  management  (left);  cascade 
outflow of siphon pipe for water level controlling (right)...................................... 136 
Figure 65: Ensuring geotechnical stability in lignite mine closure: slope stabilisation of 
former  open  cast  that  is  under  flooding  (above  left),  profiling  of  slopes  (above 
right);  stabilisation  of  underground  instability  of  coarse  rock  through  injection 
(down left), vibro compaction for ensuring ground stability (down right) ............ 138 
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Figure  66:  Ensuring  geotechnical  stability  in  lignite  mine  closure:  bioengineering 
stabilisation  and  erosion  protection  for  water  related  structures,  here:  spreaders 
with live fascines for embankment protection (left); use of water engineering rocks 
from  natural  material  combined  with  live  stakes  for  stabilisation  and  greening 
(right) .................................................................................................................. 139 
Figure  67:  Ensuring  geotechnical  stability  in  lignite  mine  closure:  bioengineering 
stabilisation  and  erosion  protection  for  earth  structures,  here:  Living  branches  of 
Salix are arranged as fascines for slope stabilisation with drainage function. ... 139 
Figure  68:  Ensuring  geotechnical  stability  through  ecological  engineering  (Dittrich  & 
Stowasser, 2010)................................................................................................ 140 
Figure  69:  Ecological  engineering  stabilisation  and  erosion  protection  of  opencast 
lignite mining, here: slopes of flooded mine (left); planting of trees for reclamation 
and erosion protection purposes (right) .............................................................. 140 
Figure 70: Principle of exploration and extraction: Oil well with pumpjack scheme (left. 
legend:  1.  driving  motor  2.  counterweight  3.  connecting  rod  4.  balancer  5.  horse 
head 6. piston rod 7. Seal as part of the eruption cross 8. Pipe 9. concrete filling of 
the borehole 10. outer borehole piping 11. pump rod 12. inner borehole piping 13. 
deep  pump  14.  pump  valves  15.  oil-bearing  rock  layer).  Principle  of  oil  and  gas 
exploration  using  intelligent  drilling  (right,  figure  source:  Bohrtechnik  ©  2018 
BVEG - Bundesverband Erdgas, Erdöl und Geoenergie e.V). ........................... 142 
Figure 71: Sample of phosphogypsum ponds in Andalusia, Spain ............................ 144 
Figure 72: Brine caused caverns and their geotechnical impacts (Warren, 2016a). .. 146 
Figure 73: Principle sketch of hydraulic filling in potash mining industry .................... 146 
Figure  74:  Concepts  for  shaft  stabilisation  in  potash  mining  (Zschiedrich  et  al.  2017)
 ........................................................................................................................... 147 
Figure  75:  Systematics  of  surface  sealing  /  covering  at  salt  and  potash  mining  waste 
heaps (Palm & Kockx, 2018) .............................................................................. 148 
Figure 76: Concept for surface cover of potash mining waste heaps (Zschiedrich et al. 
2017) .................................................................................................................. 148 
Figure 77: Aerial view of Ostrauer Kalkwerke GmbH ................................................. 149 
Figure 78: Extraction scheme and further SEE direction of excavation (left); preliminary 
exploration with subsequent extraction (right) .................................................... 150 
Figure 79: Overview on the location and the shaft and adit system to be closed ...... 151 
Figure 80: Overview on the location and the shaft and adit system to be closed ...... 153 
Figure  81:  Ensuring  geotechnical  stability  in  underground  ore  mine  closure:  complete 
filling  of  the  shafts.  The  section  above  the  flooding  level  to  be  expected  in  the 
future  must  be  installed  as  a  drainage  layer  before  the  cohesive  filling  column 
reaching to the surface layer (left); partial filling (right) ...................................... 154 
Figure 82: Break out of shaft, preparation for plugging .............................................. 155 
Figure 83: Adit open, no water discharge (left); adit open, water discharge (right) .... 156 
Figure 84: Methodology of financial provision calculation (Tudeshki & Pielow, 2018) 158 
Figure  85:  Methodology  of  financial  provision  verification:  Distribution  of  the  closure 
cost  due  to  objectives  (left.  Legend:  OC  open  cast,  IL  –  industrial  landfill),  FG 
allocation due type of activity (right) (Tudeshki & Pielow, 2018) ........................ 159 
Figure  86:  Distribution  of  the  closure  cost  due  to  objectives  (left.  Legend:  OC  open 
cast,  IL  –  industrial  landfill),  allocation  of  the  financial  provisions  due  type  of 
activity (right) (Tudeshki & Pielow, 2018) ........................................................... 159 
Figure  87:  Underground  closure  of  Morsleben  salt  mine  type  (Bundesgesellschaft  für 
Endlagerung, 2016) ............................................................................................ 161 
Figure  88:  Underground  closure  of  Morsleben  salt  mine  (Bundesgesellschaft  für 
Endlagerung, 2016) ............................................................................................ 162 
Figure 89: Current situation at the fluorspar mine site: adit with mine water outlet (left); 
aeration zone for mine water passive treatment of the drainage water (right) ... 163 
Figure 90: Site preparation ......................................................................................... 170 
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Figure  91:  Scheme  of  an  open-pit  mine  morphological  reclamation,  including 
landscaping  possibilities.  (a)  Complete  filling  for  restoration  of  the  original 
agroforestry  uses  or  the  implementation  of  new  uses,  (b)  partial  filling  for 
rehabilitation  of  pre-mine  uses  for  implementation  of  new  uses  (e.g.  recreation), 
(c) minimal selective filling and treatment of rock faces, tips, and embankments for 
replacement  activities  (e.g.  recreation,  lakes,  wetlands),  and  (d)  maintenance  of 
morphological characteristics of the open pit with vegetation development (Favas 
et al. 2018) ......................................................................................................... 174 
Figure 92: Illustration of possible shaft (left) and adit (right) entrances...................... 175 
Figure  93:  Stabilisation  technology  for  tailings  ponds:  vertical  drains  in  combination 
with  a  stabilisation  package  made  of  geofabric,  drain  mats,  and  geogrid.  The 
system  is  covered  with  1  to  2  m  mineral  soil  or  waste  rock  material  to  force 
consolidation (source: Wismut GmbH, 2019). .................................................... 177 
Figure 94: Installation of soil cover systems ............................................................... 178 
Figure 95: Flooding of a quarry (left) and a lignite mining site (right) ......................... 181 

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ABREVIATION LIST: 

AMD 

BAT 

Acid Mine Drainage 

Best Available Techniques 

BATNEEC  

Best Available Techniques not Entailing Excessive Costs 

BREF 

BAT Reference Documents 

BoQ 

CP  

CP 

Bill of Quantities 

Closure Plan 

Cleaner Production  

CWATUP 

Walloon Code of Land Planning, Urban Planning and Heritage 

DIN EN ISO  German  Institute  for  Standardisation  (German:  Deutsches  Institut  für  Normung 

EC 

EIA 

EU 

EM 

EMAS 

ERTD 

ESTA 

EWD 

EWIW 

FIDIC 

FS 

GD 

GOP 

ICMM 

IEC 

IED  

ISO 

e.V), edition of European Standards 

European Commission 

Environmental Impact Assessment  

European Union 

Environmental Monitoring 

EU Eco-Management and Audit Scheme 

Environment Restoration Technical Design 

Electrostatic Separation 

Extractive Waste Directive 

Extractive Waste Influenced Water  

Federation Internationale des Ingénieurs-Conseils 

Feasibility Study 

Guideline Document 

Good Operating Practices 

International Council on Mining and Metals 

International Electro technical Commission 

Industrial Emissions Directive 

International Organization for Standardization 

ITA-AITES 

International Tunnelling and Underground Space Association 

LHD 

MS 

Load Haul Dump 

Member State  

MWEI 

Management of Waste from Extractive Industries 

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NAG 

NACE 

NAMR 

NORM 

Non Acid Generating (extractive waste) 

National Association of Corrosion Engineers 

National Agency for Mineral Resources 

Naturally Occurring Radioactive Material 

OSPAR 

Oslo/Paris Convention for the Protection of the Marine Environment of the North-

PAG 

PPE 

QMP 

East Atlantic  

Potentially Acid Generating (extractive waste) 

Personal Protective Equipment 

Quality Management Plan 

PRODCOM 

PRODuction COMmunaitaire (French) 

SMART 

Specific, Measurable, Achievable, Timely (development approach) 

SME 

TD 

TDS 

Small to mid-size Enterprise 

Technical Design 

Total Dissolved Substances 

TENORM 

Technologically Enhanced Naturally Occurring Radioactive Material 

TFEU 

TMF 

TOP 

Treaty on the Functioning of the European Union 

Tailings Management Facilities 

Technical Operation Plan 

UNCLOS 

United Nations Convention for the Law of the  

VLAREM 

Flemish Environmental Permitting Regulations 

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1.  Introduction 

1.1  General Introduction: Objective of the GD 

The  GD  objective  is  the  provision  of  guidance  for  the  assessment  of  the  technical 
framework and measures for FG  establishment  according to Directive 2006/21/EC on 
the management of waste from the extractive industries (the Extractive Waste Directive 
- EWD). Waste from extractive operations involves materials that must be removed to 
gain  access  to  the  mineral  resource,  such  as  topsoil,  overburden  and  waste  rock,  as 
well  as  tailings  remaining  after  minerals  have  been  extracted  from  the  ore  (European 
Commission,  2019).  Further,  mining  waste  water  or  treatment  sludge  might  result  as 
residue.  Figure  1  shows  an  exemplified  scheme  of  the  mining  process  (Schneider  & 
Wolkersdorfer, 2021). The EWD as such focuses on FG for mine waste, means mate-
rial that is indicated in brown colour in figure 1. 

Figure 1: Exemplified scheme of mine design and mining process. Black words indicate 
activities related to mine preparation and operation, blue words indicate water-related 
flows and activities, words in brown colour refer to waste-related flows or activities 
(Schneider & Wolkersdorfer, 2021) 

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Mine waste might be inert and hence not likely represent a substantial pollution poten-
tial.  However,  other  fractions,  in  particular  those  generated  by  the  non-ferrous  metal 
mining industry, may contain large quantities of dangerous substances, such as heavy 
metals  or  even  radionuclides  (European  Commission,  2019).  The extraction and sub-
sequent mineral processing can foster metals and metal compounds to become chemi-
cally more available, resulting even in the generation of acid or alkaline drainage (figure 
1).  Tailings  management  facilities  (TMF,  also  called  tailings  ponds)  are  intrinsically 
risky,  as  they  are  large  ponds  of  mining  residues  retained  by  dams.  The  stored  TMF 
material usually involves residual processing chemicals and elevated levels of metals. 
The collapse of dams or heaps may have serious impacts on environment and human 
health  and  safety  (European  Commission,  2019).  Prominent  examples  are  the  acci-
dents  in  Aberfan  (Wales,  1966),  Stava  (Italy,  1985),  Aznalcóllar  (Spain,  1998),  Baia 
Mare  and  Baia  Borsa  (Romania,  2000).  Other  likely  significant  impacts  relate  to  the 
physical  footprints  of  waste  disposal  facilities  and  resulting  loss  of  land  productivity, 
effects on ecosystems, dust and erosion (European Commission, 2019). 

In practice, the separation of the closure activities for waste facilities from the closure 
and decommissioning of an entire mine site including its related infrastructure might be 
conceptually  difficult.  Therefore,  the  scope  of  the  GD  goes  beyond  the  EWD  require-
ments and includes FG approaches for the wider aspects of mine closure (e.g. mining 
brownfields,  wastes  not  directly  resulting from mineral extraction, decommissioning of 
infrastructures used for mining but not for waste management, closure of cavities that 
cause risk to human and environment). This GD focuses on FG for decommissioning, 
closure,  rehabilitation  and/or  restoration  and  after-closure  of  mine  sites,  related  infra-
structure and associated waste facilities. This includes all mines associated with Cate-
gory A waste facilities (e.g. TMFs and heaps) for which FG are required by the EWD as 
well as other residual mining objects for which the competent authorities might require 
further FG to ensure public closure and post-closure safety. 

Fundamental  criteria  for  closure  processes,  from  initial  planning  through  to  actual  im-
plementation  including  the  closure  objectives  are  summarized  in  table  2  of  the MWEI 
BREF (Garbarino et al. 2018). The purpose of this guideline is to support the financial 
aspects of the mine closure process, but not providing guidance to the closure process 
itself.  It  has  to  be  underlined  that  site-specific  information  including  the  geographical 
location and local environment, type of the mineral resources extracted, type of deposit 
and  extractive  and  processing  methods,  as  well  as  characteristics  of  the  extractive 
wastes  and  technical  characteristics  of  the  waste  facilities  and  its  confining  structure, 
affect closure activities needed and therefore also closure cost. Also the planned after 
closure land-use, visual impacts of the site and measures needed to protect the biodi-
versity of the surrounding environment affect closure activities and costs (Garbarino et 
al. 2018). The closure scopes for extractive waste are highlighted in the MWEI BREF. 
That is to ensure long-term safe and environmentally responsible deposition of extrac-
tive waste, including chemical, physical and mechanical stability over time, in order to 
prevent  any  accident  and  to  minimise  emissions  that  could  have  a  negative  effect  on 
the environment and/or human health. The requirements for log-term safety apply also 
to non-waste mining facilities to be closed. 

1.2  Structure of the GD 

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The GD comprises two main topics: 

•  description of the technical solutions for mine closure (sections 1 – 4), and 

•  documentation  of  cost  profiles  and  cost-relevant  activities  for  the  technical 

measures of those solutions (section 5). 

The GD for the technical solutions is structured in the following sections: 

•  Part A - Provisions on the Establishment of Financial Guarantees: this section 
deals  with  the  FG  role  and  purpose,  the  financial  options  and  instruments,  as 
well as their applicability and routines for establishment. 

•  Part  B  -  General  Provisions  on  Best  Practices  for  Closure,  Rehabilitation  and 
After-closure  Design:  this  section  deals  with  the  general  approach  to  closure 
design options, the permitting and implementation requirements and quality as-
surance of implementation. 

•  Part  C  -  Overview  on  Closure  Best  Practices  by  Mining  Typology:  this  section 
deals  with  the  mining  typologies,  and  the  specifics  and  challenges  of  aggre-
gates,  industrial,  and  energy  minerals  as  well  as  ore  mining.  The  section  is 
supported by mine closure show cases. 

•  Part D - Cost Profile, Cost-Relevant Activities and Unit Cost: Cost profiles and 
unit cost were obtained from about 30 closure plans and related Bills of Quanti-
ties (BoQs) from implemented mine closure activities of the last 20 years, main-
ly  from  Northern,  Central  and  Eastern  Europe.  The  data  were  complemented 
with  information  from  comparable  rehabilitation  works,  for  instance  landfill  clo-
sure and aligned with information on unit cost provided by the MS. 

The  considered  closure  activities  concern  TMF  rehabilitation  as  well  as  other  mining 
facilities  closure,  like  cavities,  mine  seepage  water  outlets  and  mine  waste  heaps. 
Through these shaft and mine waste heap closure activities will be ensured to prevent 
a future release of waste materials into the environment. It is to be noted that the GD 
does not refer to unforeseen liabilities according to Art. 6 EWD. 

1.3  Glossary / Key Terminology 

For the GD  purposes, the meanings of the key terms used are as follows (terms that 
are used according to EWD definition are indicated). 

Bank guarantee is a guarantee issued by an approved bank pursuant to an agreement 
between  the  bank  and  an  operator  whereby  the  bank  agrees  to  provide  funds  to  the 
relevant  regulator  named  in  the  agreement  from  collateral  provided  by  the  operator  if 
the operator does not fulfil the environmental obligations stipulated in the agreement. 

Best  Available  Techniques  (BAT)  is  the  most  effective  and  advanced  stage  in  the 
development  of  activities  and  their  methods  of  operation  which  indicate  the  practical 
suitability of particular techniques for providing in principle the basis for emission limit 
values  designed  to  prevent  and,  where  that  is  not  practicable,  generally  to  reduce 
emissions  and  the  impact  on  the  environment  as  a  whole  (Industrial  Emissions  Di-
rective 2010/75/EU (IED), Art. 13):  

• 

‘techniques’ shall include both the technology used and the way in which the in-
stallation is designed, built, maintained, operated and decommissioned, 

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• 

• 

‘available’ techniques shall mean those developed on a scale which allows im-
plementation in the relevant industrial sector, under economically and technical-
ly viable conditions taking into consideration the costs and advantages, whether 
or not the techniques are used or produced inside the MS in question, as long 
as they are reasonably accessible to the operator, 

‘best’ shall mean most effective in achieving a high general level of protection of 
the environment as a whole. 

Cash deposit is money deposited by an operator with a third party (e.g. in a bank ac-
count) and legally secured so that it can only be used for the intended purposes. For 
the purposes of this practical guide this includes ‘escrow accounts’. 

Category A waste facility is classified after EWD (Annex III of Directive 2006/21/EC) if 
a)  a  failure  or  incorrect  operation,  e.g.,  the  collapse  of  a  heap  or  the  bursting  of    a  
dam,  could  give rise  to  a major  accident,  on  the  basis  of  a  risk assessment tak-
ing  into  account  factors  such  as  the  present  or  future  size,  the  location  and the envi-
ronmental impact of the waste facility; or b) it  contains  waste  classified  as  hazard-
ous  under  91/689/EEC  above  a certain threshold; or c) it  contains  substances  or  
preparations    classified    as    dangerous    under  Directives  67/548/EEC  or  1999/45/EC 
above a certain threshold. 

Charge  on  asset  is  a  mortgage/charge  over  a  specific  asset  in  favour  of  a  regulator 
which  enables  the  charge  holder  to  exercise  their  power  of  sale  over  the  asset  if  an 
operator defaults on its obligations. 

Collateral refers, for the purposes of this guide, to funds or assets pledged as security 
by  the  operator  (or  a  company  associated  with  them,  such  as  a  parent  company)  in 
respect of a guarantee by a financial institution, to be forfeited in the event of the oper-
ator’s default under the guarantee. 

Competent person is a natural person who has the technical knowledge and experi-
ence, as defined by the national law of the MS in which the person operates, to perform 
the duties arising from Directive 2006/21/EC (Art.3 (26) of Directive 2006/21/EC) 

Competent authority is the authority or authorities which a MS designates as respon-
sible for performing the duties arising from Directive 2006/21/EC (Art.3 (27) of Directive 
2006/21/EC) 

Concurrent rehabilitation is a rehabilitation that occurs during the process of mining 
as the ore body is mined out in parts of a mine. 

Cost profile is the pattern of closure, restoration and after-closure costs over time for 
mines and landfills. A cost profile can also be known as a financial profile. 

Dam is an engineered structure designed to retain or confine water and/or waste within 
a pond (Art.3 (11) of Directive 2006/21/EC) 

Decommissioning is the process of taking infrastructure out of active service, from the 
end  of  its  utility  for  site  activities  until  the  removal  of  all  unwanted  infrastructure  and 
services. 

Decontamination refers to the removal of contaminants from buildings or other infra-
structure,  for  instance  asbestos  abatement,  pipeline  cleaning  and  general  clean-
ing/washing.  

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Demolition/deconstruction refers to the process of physically taking apart infrastruc-
ture, may involve disassembly of some or all of the structures, or destruction of infra-
structure with heavy equipment or explosives. 

Environmental  Management  Plan  is  a  plan  to  manage  and  rehabilitate  the  environ-
mental impact as a result of prospecting, reconnaissance, exploration or mining opera-
tions 

Environmental impairment liability insurance is insurance specially tailored to envi-
ronmental liabilities including liabilities under the Environmental Liability Directive. 

Environmental liabilities are costs relating to environmental obligations. 

Environmental  obligations  are  obligations  on  operators  relating  to  environmental 
protection, such as closure, restoration and after-closure following cessation of an ac-
tivity or clean-up and restoration in the event of an incident/accident. 

Extractive  waste  is  waste  resulting  from  prospecting,  extraction,  treatment  and  stor-
age of mineral resources and the working of quarries but does not cover waste which 
does not directly result from such activities, waste which results from offshore activities, 
and injection/re-injection of groundwater as defined by the Directive 2000/60/EC. 

Financial institution guarantee is a guarantee provided by a financial institution (e.g. 
a bank or surety) to pay if an operator defaults on its obligations. This includes ‘bank 
guarantees’, ‘letters of credit’, ‘surety bonds’ and ‘performance bonds’. 

Financial  provision  is  the  establishment  of  a  source  of  funding  for  liabilities  under 
environmental  law  or  an  environmental  permit,  licence  or  other  authorisation.  The 
terms ‘financial guarantee’ and ‘financial security’ can also be used. For the purposes 
of this document these three terms can be read interchangeably. 

Foreseen liabilities are environmental liabilities that are known to arise. They include 
development,  decommissioning,  closure,  rehabilitation,  and  after-closure  of  installa-
tions, activities or sites, or the costs of repatriation. 

Hazardous waste are wastes featuring on a list of Annex Ia and Ib (generic types of 
hazardous wastes) of Annex II (constituents of wastes listed in Annex Ib which render 
them  hazardous  if  they  have  properties  listed  in  Annex  III,  any  other  waste  which  is 
considered by a MS to display any of the properties listed in Annex III, e.g., toxic, car-
cinogenic,  inflammable  (Article  1(4)  of  Council  Directive  91/689/EEC  on  hazardous 
waste). 

Heap is an engineered facility for the deposit of solid waste on the surface (Art.3 (10) of 
Directive 2006/21/EC) 

Incident/accident is a change from normal operating conditions with actual or potential 
negative consequences. 

Inert waste is waste, that does not undergo any significant physical, chemical or bio-
logical  transformations.  Inert  waste  will  not  dissolve,  burn  or  otherwise  physically  or 
chemically react, biodegrade or adversely affect other matter with which it comes into 
contact  in  a  way  likely  to  give  rise  to  environmental  pollution  or  harm  human  health. 
The  total  leachability  and  pollutant  content  of  the  waste  and  the  eco-toxicity  of  the 
leachate  must  be  insignificant,  and  in  particular  not  endanger  surface  water  and/or 
groundwater quality (Art. 3 (3) of the Directive 2006/21/EC (EWD)) 

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Insolvency  refers  to  a  situation  where  the  operator  enters  into  legal proceedings be-
cause it does not have adequate financial viability to meet its liabilities. 

Leachate  means  liquid  percolating  through  the  deposited  waste  and  emitted  from  or 
contained within a waste facility, including polluted drainage, which may adversely af-
fect the environment if not appropriately treated (Art. 3 (14) of the Directive 2006/21/EC 
(EWD) 

Letter of credit is a guarantee issued by an approved bank pursuant to an agreement 
between  the  bank  and  an  operator  whereby  the  bank  agrees  to  provide  funds  to  the 
relevant  regulator  named  in  the  agreement  from  collateral  provided  by  the  operator  if 
the operator does not fulfil the environmental obligations stipulated in the agreement. 

NEEI refers to the non-energy extractive industry 

Mine Closure entails the process of rehabilitation at the end of a mine’s life leading to 
the issue of a closure certificate by the competent authority. 

Mine  closure  plan  is  describing  and  detailing  the  actions  that  are  required  from  the 
decommissioning  via  further  potentially  necessary  steps  like  demolition,  depollution, 
and rehabilitation to achieve relinquishment. 

Mineral resource or mineral is a naturally occurring deposit in the earth's crust of an 
organic  or  inorganic  substance,  such  as  energy  fuels,  metal  ores,  industrial  minerals 
and construction minerals, but excluding water (Art. 3 (5) of the Directive 2006/21/EC 
(EWD) 

Mutual  fund/pool  is  a  group  financial  provision  arrangement  under  which  the  group 
pays the obligations of an operator who is a member of the mutual/fund or pool if the 
operator defaults on its obligations. 

Operator  is  the  natural  or  legal  person  responsible  for  the  management  of  extractive 
waste,  in  accordance  with  the  national  law  of  the  MS  in  which  waste  management 
takes place, including in respect of temporary storage of extractive waste as well as the 
operational  and  the  after-closure  phases  (Art.  3  (14)  of  the  Directive  2006/21/EC 
(EWD) 

Parent company guarantee is a guarantee by the parent of the operator to pay or fulfil 
the operator’s obligations if the operator defaults. 

Performance  bond  is  an  indemnity  agreement  for  a  specified  amount  issued  by  an 
approved bank, other financial institution or surety. The provider of the bond agrees to 
pay the relevant regulator up to the amount of the bond, as specified in the bond, if the 
operator defaults on its environmental obligations. 

Planned mine closure is a form of mine closure that occurs when closure is undertak-
en in a planned way as outlined in a long-term mine plan. 

Polluter Pays Principle describes the principle according to which the person respon-
sible for harming the environment (i.e. the polluter) should bear the costs of remedying 
pollution  or  environmental  degradation  and  consequent  adverse  health  effects  to  the 
extent of either the damage done to society or exceeding an acceptable level (stand-
ard) of pollution. 

Pond is a natural or engineered facility for disposing of fine-grained waste, normal tail-
ings, along with varying amounts of free water, resulting from the treatment of mineral 

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resources and from the clearing and recycling of process water (Art.3 (12) of Directive 
2006/21/EC) 

Post-closure  management  is  the  on-going  management  of  residual  environmental 
impacts for a specified period as determined after closure. 

Premature mine closure is a form of mine closure that occurs when closure is unex-
pectedly necessitated before the anticipated time of closure as outlined in a long-term 
mine plan. Reasons for this form of closure can include unforeseen technical difficulties 
in mining, sharp decreases in ore prices, etc. 

Rehabilitation is the treatment of the land affected by a waste facility in such a way as 
to restore the land to a satisfactory state, with particular regard to soil quality, wild life, 
natural  habitats,  freshwater  systems,  land  scape  and  appropriate  beneficial  uses  ‘re-
habilitation’ means the treatment of the land affected by a waste facility in such a way 
as to restore the land to a satisfactory state, with particular regard to soil quality, wild 
life,  natural  habitats,  freshwater  systems,  landscape  and  appropriate  beneficial  uses 
(Art.3 (20) of Directive 2006/21/EC) 

Rehabilitation plan  is describing and detailing the concrete actions that are required 
to adequately mitigate environmental impacts and achieve rehabilitation outcomes. 

Relinquishment  refers  to  the  end  of  site  ownership  by  the  mining  company  and  of 
their responsibility for the site, with transition of ownership and residual liability to the 
jurisdictional authority or a third party. Completed closure was approved by the compe-
tent authorities. 

Self-provision is financial provision by the operator itself. This includes ‘provisioning in 
accounts’ and ‘self-insurance’. 

Site  is  all  land  at  a  distinct  geographic  location  under  the  management  control  of  an 
operator Art.3 (28) of Directive 2006/21/EC) 

Surety bond is a bond issued by a surety (usually an insurance company) pursuant to 
an agreement between the surety, an operator or its parent company, and the relevant 
regulator in which the surety agrees to carry out the obligations specified in the agree-
ment  up  to  the  specified  amount  if  the  operator  defaults  on  those  obligations.  Surety 
bonds may be payment bonds, in which case the surety agrees to pay the regulator up 
to the amount specified by the bond, or performance bonds, in which case the surety 
agrees to perform the activities on which the operator has defaulted up to the monetary 
limit of the bond.  

Tailings are waste solids or slurries that remain after the treatment of minerals by sep-
aration  processes  (e.g.,  crushing,  grinding,  size-sorting,  flotation  and  other  physical- 
chemical  techniques)  to  remove  the  valuable  minerals  from  the  less  valuable  rock 
(Art.3 (9) of Directive 2006/21/EC). 

Treatment of mineral resources refers to mechanical, physical, biological, thermal or 
chemical  process  or  combination  of  processes  carried  out  on  mineral  resources,  in-
cluding  from  the  working  of  quarries,  with  a  view  to  extracting  the  mineral,  including 
size change, classification,  separation  and  leaching,  and  the  re-processing  of  pre-
viously discarded  waste,  but  excluding  smelting,  thermal  manufacturing  processes 
(other than the burning of limestone) and metallurgical processes (Art.3 (8) of Directive 
2006/21/EC) 

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Unforeseen 
dents/accidents. 

liabilities  are  potential  environmental 

liabilities  arising 

from 

inci-

Unpolluted soil is soil that is removed from the upper layer of the ground during  ex-
tractive  activities  and  that  is  not  deemed  to  be  polluted  under  the  MS  national  law 
where  the  site  is  located  or  under  Community  law  (Art.  3  (4)  of  the  Directive 
2006/21/EC). 

Waste  means  any  substance  or  object  which  the  holder  disposes  of  or  is  required to 
dispose  of  pursuant  to the provisions of national law in force (Article 1(a) of Directive 
75/442/EEC) 

Waste facility any  area  designated  for  the  accumulation  or  deposit  of  extractive  
waste, whether in a solid or liquid state or in solution or suspension, for the following 
time-periods:  a)  no  time-period    for    Category    A    waste    facilities    and    facilities    for  
waste  characterised  as  hazardous  in  the  waste  management  plan,  b)  a    period    of  
more  than  six  months  for  facilities  for  hazardous  waste generated unexpectedly, 
c) a period of more than one year for facilities for non-hazardous non-inert waste, d) a 
period  of  more  than  three  years  for  facilities  for  unpolluted  soil,  non-  hazardous  pro-
specting waste, waste resulting from the extraction, treatment and storage of peat and 
inert waste (Art.3 (15) of Directive 2006/21/EC). 

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1.4  Legal Framework 

1.4.1  European Union Legislation 

As  a  complement  to  applicable  horizontal  EU  environmental  legislation,  a  specific 
framework for the safe management of waste from extractive industries at EU level is in 
place comprising: 

•  Directive  2006/21/EC  on  the  management  of  waste  from  the  extractive  indus-
tries  (the  Extractive  Waste  Directive  EWD).  Commission  report  on  the  imple-
mentation of Directive 2006/21/EC, 

•  Best Available Techniques reference document Management of Waste from Ex-
tractive Industries in accordance with Directive 2006/21/EC (MWEI BREF), 

• 

the Seveso III Directive which includes in its scope operational tailings disposal 
facilities, including tailing ponds or dams, containing dangerous substances, 

•  2009/335/EC: Commission Decision of 20 April 2009 on technical guidelines for 
the  establishment  of  the  financial  guarantee  in  accordance  with  Directive 
2006/21/EC  of  the  European  Parliament  and  of  the  Council  concerning  the 
management of waste from extractive industries (notified under document num-
ber C(2009) 2798); and 

•  Guidance document on non-energy mineral extraction activities in Natura 2000 

protected areas. 

The overall scope of the guideline on financial aspects is to provide support in terms of 
financial data on the closure process. Further, there is a relation to the Environmental 
Liability Directive 2004/35/CE. Further apply the provisions of the Public Procurement 
Directive (2014/24/EU) (public works contracts). 

According to Directive 2006/21/EC, the FG provision has to be foreseen for category A 
facilities.  According  to  Annex  III of 2006/21/EC, waste disposal facilities are assigned 
to category A if: 

• 

• 

• 

the risk assessment, taking into account factors such as current or future size, 
location  and  environmental  impact  of  the  waste  disposal  facility,  shows  that  a 
failure  or  improper  operation,  such  as  the  slipping  of  a  heap  or  a  dam  break 
could lead to a serious accident, or 

the  plant  contains  waste  that is classified as dangerous according to Directive 
91/689/EEC above a certain threshold, or 

the  system  contains  substances  or  preparations  which  are  classified  as  dan-
gerous  according  to  the  guidelines  67/548/EEC  or  1999/45/EC  from  a  certain 
threshold value. 

Further,  following  parts  of  the  environmental  acquis  and  the  respective  primary  and 
secondary  legislation  apply  (Directorate-General  for  Internal  Market,  Industry,  Entre-
preneurship  and  SMEs,  Directorate  Industrial  Transformation  and  Advanced  Value 
Chains, 2017): 

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•  Treaty on the Functioning of the European Union (TFEU) 

•  EU´s  Raw  Materials  Strategy  framework,  in  connection  with  the  classification 

according to the NACE Rev. 2 and the PRODCOM 

•  eight conventions (Aarhus, Espoo, Lugano, on the Protection and use of Trans-
boundary Watercourses and International Lakes, on the Transboundary Effects 
of Industrial Accidents, the OSPAR, UNCLOS and London Conventions) 

• 

• 

internal market Directives (Services, Concessions, Public Procurement, Utilities 
Procurement, Accounting, Transparency, and Professional Qualifications Direc-
tives) 

the  European  Framework  Directive  on  Safety  and  Health  at  Work  (particularly 
the Occupational Health and Safety Framework Directive 89/391/EEC) and the 
Carcinogens Directive 

•  environmental Directives (EIA, Birds, Habitats, Extractive Waste, Environmental 

Liability, Seveso III, and the Water Framework Directive). 

1.4.2  National Legislation 

The  national  legislation  is  briefly  presented  per  EU  MS  in  alphabetical  order  (Direc-
torate-General  for  Internal  Market,  Industry,  Entrepreneurship  and  SMEs,  Directorate 
Industrial  Transformation  and  Advanced  Value  Chains,  2017,  amended  by  the  au-
thors). 

Austria:  Mining  is  governed  by  the  Mining  Law  (MinroG  Act  No.  38/1999,  last  time 
amended 2019) which regulates the exploration and extraction of all mineral raw mate-
rials. The Austrian Mining Law includes a dynamic reference (§ 221a. MinroG) to other 
Federal  Laws.  Following  laws  may  be  concerned:  Commercial  Code  1994  (BGBl.  Nr. 
194),  Federal  Acts  on  Environmental  Impact  Assessment  (UVP-G  2000),  Water  Man-
agement (215/1959) and Construction Coordination (BauKG 37/20099), Acts on Nature 
Protection and Acts on Land Use Planning, Work Inspection Act 1993 (ArbIG), among 
others.  Austria  has  a  mixed  permitting  regime  with  decentralised and centralised pro-
cedures depending on the type of mineral. 

Belgium:  In  the  Flemish  region,  the  main  laws  relevant  to  mine  permitting  are  the 
Flemish  Environmental  Permitting  Regulations  (VLAREM)  and  the  Flemish  Codex  of 
Spatial Planning. In Wallonia, the main law is the Decree “Carrières” of July 4th 2002 
as amended by Decree of May 31 2007; for environmental regulations, the Decree of 
11th  March  1999  governing  environmental  permits  and  the  Walloon  Code  of  Land 
planning, Urban planning and Heritage (CWATUP). In Flanders, only extraction permit-
ting procedures are subject to spatial planning; there are no specific exploration permit-
ting  procedures  for  surface  mineral  resources.  With  regards  to  extraction  permits,  for 
quarries, it depends whether the parcel of land is already included in a Sector Plan as 
“extraction zone” or not. 

Bulgaria: Mining is regulated by the Concessions Act (SG No. /36/2.05.2006, last time 
amended  2016)  and  the  Subsurface  Resources  Act  (No.  23/12.03.1999,  last  time 
amended 2005). Other laws of relevance for permitting procedures include the Waste 
Management  Act  (53/13.07.2012,  last  time  amended  and  supplemented  2019),  the 
Environmental  Protection  Act  (that  requires  EIA),  the  Nature  Protection  Act,  the  Pro-

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tected Areas Act (133/11.11.1998, last time amended 2012), the Act for the protection 
of  the  environment  (SG  91/25.09.2002,  last  time  amended  and  supplemented  2020), 
the  Water  Act  (67/27.07.1999,  last  time  amended  and  supplemented  2017),  Law  for 
Biological  Diversity  (SG/77/09.08.2002,  last  time  amended  and  supplemented  2018) 
and the Health and Safety Working Conditions Act, among others. Bulgaria has a cen-
tralised regime where all licenses for all kind of commodities are processed after a writ-
ten application to the Ministry of Energy. 

Croatia:  Mining  in  Croatia  is  governed  by  the  Mining  Act  (Official  Gazette  56/13  and 
14/14.), the Geological Explorations Act (Official Gazette 34/86), the Concessions Act 
(Official  Gazette  143/12)  and  the  Regulation  on  compensation  for  concession  for  ex-
ploitation of mineral resources (Official Gazette 31/14). The regulatory framework has 
been recently complemented with the Act on the Exploration and Production of Hydro-
carbons (Official Gazette 55/18), the Decree on Petroleum Mining Projects and Proce-
dure for Verification of Petroleum Mining Projects NN 95/2018, Decree on reserves NN 
95/2018,  and  the  Decree  on  construction  of  oil  and  mining  facilities  and  installations 
NN 95/2018. Croatia has a centralised permitting regime. Concerning exploration per-
mits, the decision to grant an exploration permit for the purpose of granting a conces-
sion for exploitation can only be provided in areas planned for of mining activities in the 
planning  documents.  Concerning extraction permits, a concession shall be performed 
on the basis of one public tender in a single procedure consisting of four phases. 

Cyprus: the Chapter 270 is the main encompassing law that sets up a general frame-
work  for  exploration/exploitation  permits  and  the  running  of  the  industry  overall.  The 
substantive part of the licensing procedure is delivered by the Council of Ministers’ reg-
ulations, pursuant to the provisions of the general law (Mines and Quarries Regulations 
1958-2014).  The  key  permitting  authorities  in  the  exploration  and  exploitation  are  the 
Council of Ministers, the Mines Service, the Town Planning and Housing Department, 
the Ministry of Agriculture, Rural Development and Environment, the Department of the 
Environment,  and  the  District  Administrator.  For  exploration,  reconnaissance  or  pro-
specting  permits  must  be  applied  to  the  Mines  Service,  including  an  environmental 
management study, and, if applicable, a permit for waste management through a cen-
tralised permitting regime. 

Czech  Republic:  The  primary  legal  basis  of  mineral  extraction  activity  is  the  Mining 
Law (Mining Act) No. 44 of 1988, as amended by Law No. 186 of 2006. For prospect-
ing and exploration for reserved mineral deposits the most relevant law is the one No. 
62/1988 Coll., on Geological Work (the Geological Act), and MoE Decree No. 368/2004 
on geological documentation. Other important national Acts are the Act on EIA, Forest 
Act, Act on Land and Soil, Act on Nature and Landscape, etc. For permitting of explora-
tion of mineral deposits the Ministry of Environment is the relevant authority. Regarding 
exploitation, the District Mining Authorities are the relevant state bodies. These are part 
of the State Mining Administration (SMA), which is composed also by the Czech Mining 
Office in Prague (central mining authority), establishing a centralised permitting regime. 
For prospecting and exploration, an application for “reserved” minerals is to be consid-
ered by the Ministry of the Industry and Trade with the approval of the Ministry of the 
Environment. 

Denmark: The exploration and extraction of Danish minerals is mainly governed by the 
Raw  Material  Act  of  2016  and  by  the  Act  on  the  Use  of  the  Danish  Subsoil  of  2011, 
amended by the Consolidated Act no.1190 of 2018. Another important regulation is the 

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Government  Regulation  No.  949  of  2016  on  Marine  Raw  Materials.  Further  relevant 
laws are the Drilling Act, the Water Supply Act, the Environmental Protection Act, the 
Nature Protection Act, among others. Denmark has a decentralised permitting regime 
for land-based minerals and a centralised regime for offshore ones. It is the responsi-
bility  of  the  Regional  Council  to  assess  whether  or  not  an  Environmental  Impact  As-
sessment should be made for the intended extraction activity. 

Estonia: The primary legal basis of mineral extraction activities is the Mining Act (Riigi 
Teataja No. 20, 118 of 2003) amended by legal instruments (mainly focused on safety, 
mandatory  documentation,  rights  to  operate)  and  the  Earth’s  Crust  law  (Riigi  Teataja 
No. 84, 572 of 2003) amended by legal instruments (regulates research and issuance 
of permits for exploration and extraction). The relevant authority for mining permitting is 
Ministry  of  Environment  (if  mining  is  planned  in  a  mineral  deposit  of  national  im-
portance),  otherwise  it  is  the  Environmental  Board  the  organism  with  competence  on 
permitting procedures. 

Finland:  The  primary  legal  basic  of  mineral  extraction  activity  is  the  Mining  Act 
621/2011  which  covers  metallic  ores  and  industrial  minerals.  Non-claimable  minerals 
are  regulated  by  the  Land  Extraction  Act  No.  555/1981.  The  Government  Decree  on 
mining activities (391/2012) provides important provisions to the Mining Act. The Finn-
ish  Mining  Act  establishes  that  mineral  exploitation  rights  belong  to  the  discoverer. 
Other  relevant  laws  are,  i.e.,  the  Nature  Conservation  Act  (1096/1996),  the  Environ-
mental  Protection  Act  (527/2014),  the  Act  on  the  Protection  of  Wilderness  Reserves 
(62/1991),  the  Land  Use  and  Building  Act  (132/1999),  the  Water  Act  (587/2011),  the 
Reindeer  Husbandry  Act  (848/1990),  the  Off-Road  Traffic  Act  (1710/1995),  and  the 
Government Degree on Mine Waste (190/2013). The Mining Authority responsible for 
onshore  and  offshore  mining  permits  is  the  Finnish  Safety  and  Chemicals  Agency 
(Tukes).  The  Regional  State  Administrative  Agencies  (AVI)  grant  the  environmental 
permits. In Finland are applied two financial guarantees for mining projects, a financial 
guarantee for waste management according to the Environmental Protection Act and a 
guarantee for safety aspects of mine closure according to the Mining Act. 

France:  Under  French  Law,  the  exploitation  of  materials  defined  as  “eligible  for  con-
cession” (“mining substances” according to Art. L. 111-1 of the Mining Code) is ruled by 
the regulations on mines, and the exploitation of materials defined as “non-eligible for 
concession”  (“quarried  minerals”)  is  ruled  by  the  regulations  on  quarries.  Exploration 
and  extraction  operations  are  governed  mainly  by  two  centralised  items:  the  French 
Mining Code, which defines the mine nature and the exploitation conditions along with 
post-mine dispositions, and the French Environmental Code. The mining administrative 
procedures defined by Decree n°2006-648 and Decree n°2006-649 constitute the main 
mining  legal  corpus  applicable  in  France.  The  application  of  the  Metropolitan  mining 
code was extended to overseas departments. For onshore minerals, the main permit-
ting authority for non-energy minerals is the Ministry of Economy and Finance. Quarry 
materials depend on the Ministry of Environment, Energy and Sea. 

Germany:  The  primary  legal  basis of mineral extraction activity is the Federal Mining 
Act  (Bundesberggesetz  –  BBergG,  BGBl.  1310/1980,  as  amended  1962/2016  and 
Allgemeine Bundesbergverordnung, ABBergV). Other relevant federal laws include the 
Federal  Water  Resources  Act  (Wasserhaushaltsgesetz  WHG),  Federal  Imission  Con-
trol Act (Bundesimmissionsschutzgesetz BImschG), Environmental Impact Assessment 
Act  for  Mining  (Verordnung  über  die  Umweltverträglichkeitsprüfung  bergbaulicher 

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Vorhaben  –  UVP-V  Bergbau),  Federal  Nature  Conservation  Act  (Bundesnaturschutz-
gesetz BNatSchG), among others. The German federal system is characterised by the 
fact that the legislative competencies are held by the federal states. The execution of 
the  laws  is  pursuant  to  Art.  83  of  the  Basic  Law  regularly  conducted  by  the  federal 
states (Länder) as their own affair. According to BBergG, regional authorities have ad-
ministrative  instruments  for  efficient  supervision,  including  the  issue  of  mining  ordi-
nances, the grant, refusal and revocation of mining licences, the approval of operating 
plans  as  well  as  the  power  to  give  individual  instructions  for  prevention  of  dangerous 
situations and to enforce the law and the right to be informed by the mining companies. 
As established in the Section 52 (2a) BBergG, a general operating plan is required and 
a planning approval procedure (Planfeststellungsverfahren) pursuant to the provisions 
of Sections 57a and 57b BBergG shall be executed for its approval if a project requires 
an environmental impact assessment (EIA) as stipulated by Section 57c BBergG. For 
the closure of operations, closure plans (Abschlußbetriebsplan) shall be prepared. 

Greece:  The  Greek  Legislation  (the  Mining  Code,  namely  L.210/1973,  amended  by 
274/1976  and  4512/2018)  distinguishes  mineral  raw  materials  into  two  broad  catego-
ries: a) “Metallic Minerals” which, either on the surface or underground, do not belong 
to  the landowner of the area they occur in nor to the state, and b) ”Quarry Minerals”, 
which belong to the landowner of the area they occur in. Additional important legislation 
includes  L.669/1977  on  the  exploitation  of  ornamental  rocks  and  industrial  minerals, 
L.1428/84 as amended by L.2115/93 on the exploitation of aggregates, and Mining and 
Quarrying  Activities’  Regulation  (KMLE)  (Ministerial  Decision  2223-FEK1227/14-6-
2011).  In  Greece,  the  basic  legislation  for  the  environmental  permitting  of  all  types of 
projects and activities is L.4014/2011. This Law applies to the permitting of mining pro-
jects  and  activities  in  combination  with  Ministerial  Decision  37674/2016213  (on  the 
classification of projects / activities into groups and categories, depending on the signif-
icance  of  their  environmental  impacts)  and  Ministerial  Decision  167563/2013,  which 
specifies the procedures and criteria for this permitting. 

Hungary:  The  legal  basic  of  mineral  extraction  activity  is  Act  No.  XLVIII  of  1993  on 
Mining  (Mining  Act)  as  last  amended  by  Act  No.  LXXXVI  of  2014  and  311/2014  (XII. 
11)  Government  Regulation.  Important  pieces  of  law  for  permitting  procedures  are 
Governmental  Decree  No.  203/1998.  (XII.19.)  (detailed  permitting  rules),  Government 
Regulation No. 267/2006 on the Hungarian Office of Geology and Mining (MBFH) (on 
involvement  of  co-authorities),  Government  Regulation  No.  53/2012  on  mining  con-
struction  permitting,  Government  Regulation  No.  314/2005  on  EIA  and  IPPC,  Act  No. 
LIII  of  1996  on  nature  conservation,  Government  Regulation  No.  275/2004  on Natura 
2000 sites, Government Regulation No. 312/2012 on construction permitting, Ministeri-
al  Decree  No.  14/2008  (IV.  3.)  on  mining  waste  management,  and  Ministerial  Decree 
No. 8/2014 on the mining concession tender procedure. For permitting procedures, Act 
No. CXL of 2004 on the General Rules of Administrative Proceedings and Services is 
also highly important. 

Ireland:  The  Minerals  Development  Act  2017(Act  23  of  2017)  governs  onshore  and 
offshore mineral exploration and development in Ireland. Other laws of importance are 
the  Environmental  Protection  Agency  (EPA)  Act  of  1992  which  constituted  the  Irish 
EPA, the IPPC Regulations 2012 (S.I. No 282 of 2012) ensuring an EIA procedure is 
carried out where required under Directive No. 2011/92/EU (and amendments) in rela-
tion to relevant decisions of the EPA to grant an IPC licence, the European Communi-

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ties (Birds and Natural Habitats) Regulations 2011 (and amendments), the Air Quality 
Standards  Regulations  2011  and  the  Planning  and  Development  Act  2000,  the  main 
Act  covering  developments  of  any  type.  Exploration  and  extraction  permitting  is  gov-
erned by the Minister for Communications, Energy and Natural Resources, which acts 
through the Exploration and Mining Division (EMD) of the Department of Communica-
tions, Energy and Natural Resources (DCENR). 

Italy:  The  primary  legal  basic  of  mineral  extraction  activity  in  Italy  is  the  Mining  Law 
(Royal  Decree)  No.  1443  of  1927  (consolidated  in  1999)  which  divides  minerals  into 
two  categories  (Art.  2):  “first”  and  “second”  category.  With  the  Legislative  Decree  no. 
616/77  (related  to  second  category  minerals),  the  Legislative  Decree  112/98  and  the 
Constitutional  Law  3/2001  (related  to  first  category  minerals)  competences  related  to 
planning and management, including permitting, passed from the national State to the 
Regions. Other important national laws in Italy are Presidential Decree 128/59 (Police 
rules for mining and quarrying), Legislative Decree 152/06 (legislative framework appli-
cable to all matters concerning environmental protection including EIA, SEA and IPPC), 
the Law of 23 December 2000 no. 388, Art. 114, which provides a special plan for re-
habilitation  and  environmental  recovery  of  mines,  Legislative  Decree  no.  624/1996 
(health and safety of workers) and Legislative Decree no. 117/08 (transposing Directive 
2006/21/EC and important for the management of extractive waste). Italy has a decen-
tralised regime and each region has its own relevant regional laws (RL) regulating ex-
traction and environmental permitting procedures. 

Latvia: The law regulating mining is the Law on Subterranean Depths as of 1996. Li-
cencing  procedures  are  prescribed  in  the  Regulation  No.  696/2011  of  the  Cabinet  of 
Ministers “Procedure for the Issue of Licences for the Use of Subterranean Depths and 
Authorisations for the Extraction of Widespread Mineral Resources”. Important is also 
the Cabinet Regulation No 570 of 2012 “Procedures for the Extraction of Mineral Re-
source” which sets requirements for all mining related work stages and Cabinet Regu-
lation  No  1055  of  2006  Regulations  regarding  the  State  Fee  for  a  Licence  for  Use  of 
Subsoil,  an  Authorisation  for  the  Extraction  of  Widespread  Mineral  Resources  and  a 
Passport of the Deposit. For prospecting, exploration and extraction of minerals a com-
pany or a natural person needs a Licence for use of subterranean depths. 

Lithuania: The main law is the Underground Law No. I-1034/1995 and its implement-
ing Government Resolutions (No. 1433/2001, No. 198/2002, No. 584/2002), which reg-
ulate  the  exploration  and  extraction  permits.  Other  important  laws  regulating  permits 
and licences for the authorisation of exploration and extraction include the Environment 
protection  Law  I-2223/1992,  Proposed  economic  activity  environmental  impact  as-
sessment Law No. I-1495/1996 (which regulates the EIA process), Environment minis-
ter  order  No.  166/1996  on  exploited  mining  areas  rehabilitation, Protected Areas Law 
No.  I-301/1993,  Water  Law  No.  VIII-474/1997,  Spatial  Planning  Law  No.  I-1120/1995 
and Environment minister order No. D1-145/2014, both of which regulate spatial plan-
ning  (and  set  provisions  for  the  extraction  and  reclamation  plan).  The  competent  au-
thority granting exploration and extraction permits is the Lithuanian Geological Survey 
under the sphere of the Ministry of Environment. 

Luxembourg: The main legislation governing permitting procedures involves the law of 
21/04/1810 (last amended in 1994), the law of 10/06/1999 relative to the classification 
of  potentially  dangerous  establishments  (amended  by  Grand  Ducal  regulation  of 
10/05/2012) which classifies the extractive industry as “class 1” and makes it subject to 

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an  “authorisation  to  operate”  procedure  following  an  investigation  procedure  called 
“commodo-incommodo”.  Other  relevant  laws  are  the  amended  law  of  19/12/2008  on 
water  and  Law  of  19/01/2004  on  the  conservation  of  nature  and  natural  resources. 
Relevant authorities are the Ministry of Labour, Employment and Social and Solidarity 
Economy and the Ministry of Sustainable Development and Infrastructure which are the 
competent authorities for issuing the “authorisation to operate” supported by its Inspec-
torate  of  Labour  and  Mines  (ITM)  and  the  Department  of  Environment  (organized  in 
three  Administrations:  Environment,  Nature  &  Forests  and  Water  Management),  the 
Administration of the Environment, the College of burgomasters and aldermen and the 
Communes.  Concerning  exploration  for  industrial  or  construction  minerals,  it  only  re-
quires the permission by the landowner, except when it involves drillings that require a 
permit according to commodo-incommodo law. 

Malta: The authorities do not provide a license for exploration but only for exploitation. 
Malta  has  a  centralised  permitting  regime  and  licensing  is  handled  exclusively  at  the 
national  level.  Companies  need  to  express  their  interest  by  applying  for  a  land  use 
permit  with  the  Planning  Authority  (PA).  The  PA  consults  the  Environment  and  Re-
sources  Authority  (ERA),  the  Malta  Resources  Authority  (MRA)  and  the  Agency  for 
Energy and Water as the main Consultees including the other statutory Consultees in 
Schedule 3 of L.N. 162 of 2016 Development Planning Act (Cap. 552). ERA and MRA 
may only issue their respective permits and licences, once the development consent is 
issued  through  the  development  planning  permit.  Other  entities  consulted  during  the 
process  are  the  Superintendence  for  Cultural  Heritage  and  the  Regulator  for  Energy 
and Water Services. 

The  Netherlands:  The  main  mining  law  is  the  Mining  Act  of  2002  (last  amended  in 
2018). Other relevant laws are the Mining Decree of 2003 (last amended in 2017), the 
Mining Regulation of 2013, the Excavations Act of 2008, the Environmental Licencing 
Act of 2010, the Nature Protection Act, the Flora and Fauna Act, the Spatial Planning 
Act and the Water Act. In 2021, the Dutch Senate passed the bill to amend the Mining 
Act  to  further  stimulate  investments  in  the  Dutch  Mining  industry  and  to  prevent  that 
natural  gas  reserves  are  left  behind  when  existing  infrastructure  is  being  decommis-
sioned. The State Supervision of Mines (SSM) is the agency within the Ministry of Eco-
nomic Affairs that oversees the production of minerals and the Netherlands’ continental 
shelf.  The  agency  is  responsible  for  drafting  and  enforcing  mining  laws,  mine  safety, 
and mineral production regulations on and offshore. Netherlands has a mixed (central-
ised-decentralised) permitting regime in which the SSM grants the exploration and ex-
traction  permits,  and  the  Ministry  of  Infrastructure  and  Environment  grants  the  envi-
ronmental and water extraction permits. 

Poland:  The  principal  legislation  concerning  permitting  procedures  is  the  Geological 
and Mining Law (unif. text J.L. of 2015, item 196), Act on the Liberty of Economic Activ-
ity (unif. text J.L. 2014, item 1446), Nature Conservation Law (unif. text J.L. 2015, item 
1651), Environmental Protection Law (unif. text J.L. 2013, item 1232), Water Law (unif. 
text J.L. 2015, item 469) and Act on Land Use Planning and Space Management (unif. 
text J.L. 2015, item 199). The competent authorities and the procedures for obtaining 
the license are different for state-owned and land-owned mineral deposits, and for ex-
ploration and extraction phases, their location, as well as extraction method and size. 
For exploration, in order to receive a prospecting or exploration licence, it is necessary 

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to  obtain  the  environmental  permit.  The  competent  authority  that  grants  the  environ-
mental permit is the Regional Director for Environmental Protection. 

Portugal:  The  legal  basis  for  the  extraction  of  state-owned  minerals  is  Law  No. 
54/2015, which is the legal framework regime for exploration and use of existing geo-
logical resources in the country, including those located in the national maritime area. 
For  land-owned  (or  privately  owned)  minerals  extracted  in  quarries  (mineral  masses 
also called construction minerals) the guiding principles relating to their exploration and 
extraction are regulated by Decree-Law No. 270/2001 which was amended by Decree-
Law No. 340/2007 of 12th October. The Decree Law No 88/90 (Minerals Law) estab-
lishes the mineral deposits regulation. Another relevant law for the permitting chain is 
Decree-Law No. 151-B/2013, which establishes the regulatory framework for Environ-
mental Impact Assessments. The Portuguese national mining authority for state-owned 
minerals is the DGEG (under the Ministry of Economy) which acts as a “one-stop shop” 
for mining permits in the exploration, extraction and post-extraction phases.  

Romania: Mineral resource extraction activities and the management of solid mineral 
resources are regulated by the Mining Law no. 85/2003, whose provisions are detailed 
by  the  Norms  of  application  of  the  Mining  Law  and  technical  instructions  on  specific 
problems  (Joint  Order  of  NAMR  and  MoEn  no.  58/19  of  25/02/004  resp.  09/04/2004, 
amended through Order nr. 2.026 of 26/07/2010, and NAMR order no. 22/2006, etc.). 
The  Romanian  authorisation  system  for  permits/licences  for  the  project  development 
around  solid  mineral  resources  is  of  a  multi-authorisation  nature,  i.e.  up  to  6  permits, 
licences  or  approvals  are  necessary  so  that  exploration  or  exploitation  works  can  be 
conducted.  Prospecting  permits  and  exploration  licences  are  issued  by  the  National 
Agency for Mineral Resources (NAMR) and up to 5 co-authorities might be involved in 
the process. Extraction licences are also granted by the NAMR and between 6 and 9 
co-authorities may be involved in the process. An environmental rehabilitation plan and 
technical project are required due to NAMR Order no.17/2005. 

Slovakia: The Ministry of the Environment acting under law No. 569/2007 and registra-
tion  N.51/2008  provides  oversight  and  management  of  the  country’s  mineral  deposits 
and  energy  sources.  Mining  activities  are  administered  by  the  Main  Mining  Bureau  at 
the  Ministry  of  the  Economy.  The  tasks  of  the  Main  Mining  Bureau  are set out in law 
No. 44/1988, revised in Law 214/2002. The legal framework relevant for permitting pro-
cedures  comprises  mainly  the  Mining  Law  (Law  No.  44/1988  Coll.  216  with  amend-
ments) and the Geological Law (Law No. 569/2007 Coll. with amendments). The Minis-
try  of  the  Environment  issues  the  licences  to  undertake  geological  exploration  pro-
grams  in  compliance  with  Law  No.  569/2007  and  by  Registration  No.  51/2008.  Other 
important laws are Law No. 543/2002 Coll. on nature and landscape protection, Law. 
No. 24/2006 Coll. on the environmental impact assessment, Law No. 39/2013 Coll. on 
integrated prevention and environmental pollution control, and the Water Law (Law No. 
364/2004  Coll.).  Competent  authorities  are  the  Ministry  of  Environment  of  the  Slovak 
Republic, Ministry of Economy of the Slovak Republic, Main Mining Office and the Re-
gional (or District) Mining Offices. 

Slovenia: The primary legal basis of mineral extraction activity is the Slovenian Mining 
Act No. 56/1999, consolidated in 2004 and amended subsequently, which defines the 
conditions for the exploration activities and extraction of minerals. Other important laws 
are the Environmental Protection Act and the Spatial Planning Act. The competent au-
thority for granting exploration and extraction rights for mineral resources is the Energy 

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Directorate  (within  the  Ministry  of  Infrastructure).  The  local  municipalities  are  an  im-
portant  co-authority  as  they  are  responsible  for  the  municipal  spatial  plans.  All  areas 
with  a  mining  concession  (or  with  mining  rights)  need  to  be  included  in  the municipal 
spatial  plans  and  designated  as  “mineral  extraction  areas”.  For  such  plans  strategic 
environmental assessment or at least screening is needed. 

Spain: Mining operations are governed by the Spanish Mining Law 22/1973, of 21 July, 
and  its  regulations  were  approved  by  Royal  Decree  2857/1978  and  Law  21/2013  on 
Environmental  Assessment.  The  Royal  Decree  975/2009  on  the  management  of  ex-
tractive  industries  waste  and  the  protection  and  rehabilitation  of  the  sites  affected  by 
mining activities, refers to the main environmental issues arising from the exploitation 
of a mine. These laws are applicable to the whole country. Each of the 17 Spanish Au-
tonomous Regions may enact additional mining rules provided the basic mining system 
governed by national provisions is respected. According to the Mining Law, all mineral 
deposits and geological resources within Spain are public domain goods, thus mining 
activity  must  be  preceded  by 
the  corresponding  permit/concession.  The  per-
mit/concession  allowing  mining  activity  depends  on  the  type  of  mineral  commodity 
(“mineral  section”).  The  competent  authorities  governing  mineral  exploration  and  ex-
traction  are:  the  General  Directorate  of  Energy  and  Mines  Policy  (Ministry  of  Energy, 
Tourism and Digital Agenda), Ministry of Agriculture and Fisheries, Food and Environ-
ment, Ministry of Education, Culture and Sports and the Ministry of Public Works, De-
partments of Industry, Environment, Culture and Public Works of each of the 17 Auton-
omous Regions. 

Sweden:  Mineral  exploration  and  the  extraction  of  “concession  minerals”  in  Sweden 
are  governed  by  Minerals  Act  (1991:45)  and  Minerals  Ordinance  (1992:285),  as 
amended subsequently, which is applicable in parallel with other legislation to all explo-
ration  and  extraction  works,  e.g.  the  Planning  and  Building  Act  (2010:900),  Environ-
mental  Code  (1998:808),  Cultural  Heritage  Act  (1988:950)  and  Off-Road  Driving  Act 
(1975:1313).  The  Swedish  Environmental  Code  is  particularly  relevant,  as permits for 
extraction must be granted under both the Minerals Act and the Environmental Code. 
The  primary  law  concerning  the  extraction  of  “non-concession  minerals”  is  the  Envi-
ronmental  Code  (1998:808),  which  is  applicable  in  parallel  with  other  legislation  (as 
above). The Minerals Act does not apply to these sub-groups. The competent authority 
for mining is the Mining Inspectorate. For extraction to commence, besides the extrac-
tion  concession,  an  environmental  permit  is  required.  The  application  for  an  environ-
mental permit required under the Environmental Code is handled by the Land and En-
vironmental  Court  or  by  any  of  12  (out  of  21)  responsible  County  Administrative 
Boards. The extraction of national resources from the seabed and Swedish economic 
zone is regulated in the Act on Continental Shelf (1966:314) and Continental Shelf Or-
dinance (1966:315). 

1.4.3  Licensing / Permitting Conditions 

The EWD is of importance for permitting procedures in all three phases of mining, i.e. 
exploration, extraction, post-extraction (Directorate-General for Internal Market, Indus-
try,  Entrepreneurship  and  SMEs,  Directorate  Industrial  Transformation  and  Advanced 
Value Chains, 2017). The EWD has three major instruments relevant in terms of per-
mitting:  

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•  completion of a waste management plan prior to the commencement of extrac-

tion;  

•  elaboration of an external emergency plan for “Category A” facilities, and  

•  FG provision to secure proper rehabilitation of the affected land.  

All these instruments are highly relevant to permitting of mineral resource projects. 

According  to  Directorate-General  for  Internal  Market,  Industry,  Entrepreneurship  and 
SMEs  and  Directorate  Industrial  Transformation  and  Advanced  Value  Chains  (2017), 
the number of co-authorities is smaller for exploration than for extraction permits. Per-
mitting procedures differ not only by the type of mineral and its ownership, but also due 
to the mineral development phase. 

Concerning the terms related to the withdrawal of material from the earth´s crust, apply 
the definitions given in Art. 41(1) of the EU Accounting Directive (2013/34/EC). Accord-
ing  to  Directorate-General  for  Internal  Market,  Industry,  Entrepreneurship  and  SMEs 
and  Directorate  Industrial  Transformation  and  Advanced  Value  Chains  (2017),  there 
are three major permitting stages: 

•  exploration permitting: from the green field phase until the competent authori-
ty issues a resolution on the first exploration technical operation plan (TOP) (or 
equivalent national legal term), with which the holder may start exploration ac-
tivities promptly; 

•  extraction  permitting:  starting  from  the  approval  of  the  exploration  report 
and/or mineral reserves reporting to the valid authority resolution on the first ex-
traction TOP or equivalent permit with which the holder may start extraction ac-
tivities promptly; 

•  post-extraction  permitting:  closure  and 

rehabilitation  TOP,  after-care 

measures, including monitoring of reclamation measures. 

The present guideline refers mainly to the phase of post-extraction permitting, however 
when it comes to FG also the extraction permitting is relevant, as the financial obliga-
tions must be deposited during the operational lifetime of the mine. There is a diversity 
or terms regarding the permitting system, referring mainly to the two terms “permit” and 
“licence” that are used to refer to the authorisations, permissions or approvals granted 
by public authorities to companies before they can proceed with any phase of the min-
eral development cycle. 

There are two distinct procedures to obtain exploitation permits in the EU (Directorate-
General  for  Internal  Market,  Industry,  Entrepreneurship  and  SMEs,  Directorate  Indus-
trial Transformation and Advanced Value Chains, 2017). Most MSs have a procedure 
which depends on the application for the permit by the interested party (DK, EE, FI, FR, 
DE, EL, HU, IE, IT, LT, PL, PT and ES) whilst others have an inherited public tender 
system (HR, RO). In some MSs, a previous spatial planning (or development plan) has 
to be issued in the area of potential exploitation (BE, DK, IT, PL, SI, RO) before a con-
cession can be granted, whereas, in general, exploitation can be carried out anywhere, 
provided the necessary authorisations have been obtained. 

All EU MSs require Environmental Impact Assessment (EIA) and subsequent environ-
mental evaluation and authorisation previous to the  exploitation concession grant (Di-
rectorate-General  for  Internal  Market,  Industry,  Entrepreneurship  and  SMEs,  Direc-

33 

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torate  Industrial  Transformation  and  Advanced  Value  Chains,  2017).  The  duration  of 
the mining exploitation permit is regulated by law in most MSs between 20 years (BE, 
but unlimited for quarry) and 75 years (in the case of ES or FR after extensions) or EL 
(50  y  +  2  extensions  of  25  for  metallic  ores);  most  include  extensions  to  the  original 
permit, for instance, DK (10y +10 y), FR (50 y + renewal), HU (35y+17.5), PL (3-50 y). 
In the case of AT is open ended and RO is 20 y plus 5 years’ period renewal with no 
limit. In the case of IE it is related to the predicted length of the operations. 

1.4.4  Institutional Framework 

According  to  Directorate-General  for  Internal  Market,  Industry,  Entrepreneurship  and 
SMEs  and  Directorate  Industrial  Transformation  and  Advanced  Value  Chains  (2017), 
there  are  first-instance  and  second-instance  permitting  levels  in  the  European  Union. 
The definitions are: 

•  First-instance  permitting  (local,  regional,  national):  first-instance  permitting 
authorities are those government agencies primarily in charge of granting a rel-
evant permit or licence for any mineral development to take place at local, re-
gional and national level. They also include co-authorities. This level involves all 
relevant  authorities  with  professional  competence  to  issue  legally  binding  per-
missions. 

•  Second-instance  permitting  (regional,  national):  second-instance  permitting 
refers  to  the  level  at  which  there  is  a  legal  option  for  the  applicant  (a  mining 
company,  an  investor)  or  for  any  other  interested  party  to  appeal  against  the 
resolution of the first-instance authority within the public administration system, 
i.e. not yet involving any court actions. Only regional and national levels (courts) 
are considered (unless a local court is of high importance for any MS). 

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2.  Part A: Principles and Purpose of Financial Guarantees 

2.1  Overview of the Financial Provision Determination Process  

The main FG scope is to ensure the mining companies responsibility for the responsi-
ble closure of their mining sites, means to generate financial deposits during the mining 
operation period in order to have the necessary budget for an environmentally sufficient 
mine closure.  

The range of liability scenarios include (Bradley et al. 2017): 

•  Foreseen  liabilities:  liabilities  that  are  known  to  arise.  They  include  develop-
ment,  decommissioning,  closure,  rehabilitation,  and  after-closure  of  installa-
tions, etc. 

•  Unforeseen 
/accidents. 

liabilities:  environmental 

liabilities  arising 

from 

incidents 

A closure plan serves as basis for the determination of the FG amount by the compe-
tent authority. A guarantee should reflect the cost of a mine closure and be adjustable, 
up or down, to reflect changes in the proposed closure plan (Mota de Lima, 2003). An 
exemplified scheme of a mine balance sheet for environmental rehabilitation is given in 
figure  2.  Following  types  of  cost  have  to  be  considered:  direct  closure  costs,  indirect 
closure  costs,  mobilization  and  site  preparation,  contingencies,  engineering  and  De-
sign,  profit  and  overhead,  closure  management,  administrative  costs,  maintenance 
costs, and monitoring costs. 

Figure 2: Exemplified scheme of a mine balance sheet for environmental rehabilitation 
(Tambo& Theobald, 2018) 

The approach to defining the need and scope as well as amount of financial provisions 
is illustrated in Figure 3 (after Bradley et al. 2017).  

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Figure 3: Approach to defining the need for and scope of financial provisions (Bradley 
et al. 2017) 

Financial instruments can be divided in three main categories depending on the degree 
to which the FG is decoupled from the mine operator's assets (MonTec, 2008): 

•  FG remains within the operator company 

•  FG is guaranteed by a third (commercial) party 

•  FG is transferred to the government or a trust fund 

The calculation of the volume of the financial provisions is based on the prognosis of 
closure and restoration costs after termination of the mining activities. For some types 
of mining, the closure takes place only after termination of all mining activities (typically 
for instance in ore mining) while for other types of mining closure takes place in parallel 
to the extraction activities. This is typically the case for open cast lignite mining where 
the area of the foreland of the open pit is consumed for mining while extraction waste is 
deposited backwards and restored in parallel. This approach leads to the need of com-
bined  closure  and  restoration  plans.  Thus,  the  combined  strategy  must  be  developed 
already from the beginning of mining. This is also necessary to generate the financial 
provisions  that  are  taken  from  the  current  mining  activities  and  are  established  as  fi-
nancial  deposit.  According  to  the  Environmental  Protection  Agency  of  Ireland  (2014), 
sites  with  no  soil  or  groundwater  contamination  or  other  long-term  liabilities  require  a 
closure  plan  only,  while  sites  with  soil  or  groundwater contamination and certain sec-
tors such as landfills and mines require a closure strategy and plan. Figure 4 illustrates 
the general approach to assessing and costing environmental liabilities (Environmental 
Protection Agency of Ireland, 2014). 

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Figure 4: General approach to assessing and costing environmental liabilities (Envi-
ronmental Protection Agency of Ireland, 2014) 

A  particular  case  is  incidents  or  accidents  that  might  occur  during  mining  operation, 
and often lead to a premature closure. Even incidents or accidents create unforeseen 
liabilities; their occurrence shall already be assessed through an environmental liability 
risk assessment as basis for the creation of financial provisions for unforeseen liabili-
ties.  In  practice,  usually  there  are  different  types  of  financial  deposits  for  unforeseen 
and foreseen liabilities (figure 5): 

Figure 5: Approach to financial deposits for unforeseen / foreseen liabilities (Bradley et 
al. 2017) 

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The calculation of unforeseen liabilities comprises the following cost types (in analogy 
to Bradley et al. 2017): 

• 

Immediate emergency measures 

•  Environmental damage assessment 

•  Primary rehabilitation (according to baseline) 

•  Complementary rehabilitation (of a different resource) 

•  Compensatory rehabilitation (for interim losses) 

Some  published  resources  are  available  for  the  calculation  of  unforeseen  liabilities 
(Bradley et al. 2017): 

•  An evaluation of the potential for wider application of the Dutch, Irish and Span-
at 

ish 
https://www.impel.eu/projects/financial-provision-what-works-when/ 

2018/XX) 

available 

methods 

(IMPEL 

report 

is 

•  The Ministerio de Agricultura y Pesca, Alimentación y Medio Ambiente (Spain) 
has  developed  a  computer  application  (Modelo  de  Oferta  de  Responsabilidad 
Ambiental (MORA), 2017) for calculating potential environmental damage costs. 
The  English  version  of 
is  available  at 
https://servicio.mapama.gob.es/mora/login.action?request_locale=en 

the  MORA  and 

IDM  models 

• 

Ireland has also developed guidance (‘Guidance on assessing and costing envi-
ronmental  liabilities’)  for  costing  potential  liabilities  arising  from  incidents  (i.e. 
unforeseen liabilities). 

•  A Dutch model has been developed as a tool for the competent authorities re-
sponsible for issuing permits for Seveso companies and IED Annex I-category 4 
companies (chemical industry) in the Netherlands to help determine the amount 
of financial security needed to cover the costs of rehabilitation of environmental 
at 
damage. 
https://www.rijksoverheid.nl/binaries/rijksoverheid/documenten/rapporten/2016/
11/22/financiele-zekerheidstelling-voor-milieuschade-bij-majeure-
risicobedrijven/Financi%C3%ABle+zekerheidstelling+voor+milieuschade+bij+m
ajeure+risicobedrijven.pdf. 

available 

model 

Dutch 

The 

is 

Subject  of  the  present  GD  are  foreseen  liabilities.  Important  is  to  estimate  a  realistic 
volume  even  the  closure  will  be  far  in  the  future.  For  that  reason,  it  is  necessary  the 
estimation  to  be  as  comprehensive  and  transparent  as  possible  as  well  as  designed 
according  to  BAT.  Furthermore,  all  cost  of  conceptual  and  technical  design  including 
supporting studies, permits, proofs, endorsements and contingencies must be covered. 
The Extractive Waste Directive requires that the calculation of the FG shall be made, 
inter  alia,  on  the  assumption  that  independent  and  suitable  qualified  third  parties  will 
assess  and  perform  any  rehabilitation  work  needed.  This  requirement  ensures  the 
availability of an adequate FG in case of a bankruptcy of the operator of a mine.  

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2.1.1  General Approach  

Figure 5 shows the principal steps to calculate a FG (MonTec, 2008). Section 5.3 pro-
vides a practical example (show case) for a calculation methodology applied to energy 
mineral resource extraction. 

Figure 6: Flow sheet of the principal steps to calculate a FG (MonTec, 2008) 

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Defining  the  appropriate  amount  of  financial  provision  and  timing  of  the  availability  of 
the  provision  is  important  (Bradley  et  al.  2017).  For  facilities  that  are  subject  to  pro-
gressive  closure,  the  financial  provision  needs  to  reflect  the  partial  closure  works  as 
well  as  the  final  stage  of  closure,  and  the  period  of  after-closure.  The  duration  of  the 
after-closure period needs to be determined, for instance at landfill sites typically being 
considered to require after-closure financial provisions for at least 30 years (Bradley et 
al. 2017). For ore mining sites, the time might be substantially longer. In the particular 
case of uranium mining, more than 100 years typically are relevant. Further it is to be 
ensured that the financial provision is protected in case of operator insolvency or disso-
lution. 

For foreseen liabilities following issues apply (Bradley et al. 2017): 

•  The calculation should typically be based on the potential liability as determined 
by a risk assessment, and should apply any legally required formulas or default 
amounts. 

•  The calculation should allow for the scenario where a third party needs to com-

plete the works, to provide for cases where the liability is abandoned. 

•  Where the liability is going to change throughout the life of the operation, calcu-

lations should take account of the cost profile of the operation. 

•  For operations where the liability is unlikely to change significantly (e.g. a max-
imum amount of waste that is permitted to be held at a waste transfer facility), 
calculations should be based on that maximum amount. 

•  Contingency is necessary to provide for the uncertainty in costing complex and 
remote events, e.g. mobilisation issues or design changes, and for inflation. An 
example from Sweden determined the uncertainty with 28%.  

•  The  calculation  should  not  include  the  assets  of  the  operation  to  offset  the 
amount  of  the  financial  provision,  to  ensure  that  a  sufficient  amount  will  be 
available to the regulator in the case of insolvency or dissolution. 

2.1.2  Overview on Financial Provision Instruments 

Figure 7 shows categories of FG instruments and typical examples (MonTec, 2008). A 
preferred mechanism of a reclamation bonding system is that the bond amount be suf-
ficient for a third-party to do the reclamation work and supervised by the administrative 
authority  (Cheng  &  Skousen,  2017;  van  Zyl  et  al.  2012).  Bonds  are  provided  by  a  fi-
nancial institution to pay if an operator defaults on its obligations. This includes perfor-
mance bonds, payment bonds, and letters of credit. Bank guarantees and surety bonds 
possess similar characteristics to these. Bonds tend to be used by operators that are 
subject to financial provision requirements for foreseen costs such as closure or recla-
mation costs. 

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Figure 7: Categories of FG instruments and typical examples (MonTec, 2008) 

Following general FG types are used (Mackie et al. 2016): 

Performance Bond: issued by a bank or other financial institution or a bonding com-
pany (called a surety). The bank or surety agrees to pay the regulator up to the amount 
of  the  bond  if  the  operator  defaults  on  its  obligations  under  environmental  law  or  its 
environmental permit, as specified in the bond. Bonds are issued by a surety by charg-
ing a premium for them; bonds issued by a bank reduce the amount an operator may 
borrow. 

Payment Bond: bank or surety agrees to pay monies demanded by the regulator up to 
the amount of the bond instead of paying the costs incurred by the regulator in carrying 
out measures that the operator failed to carry out. 

Letter  of  Credit:  agreement  by  an  approved  financial  institution,  to  pay  the  amount 
specified  in  the  agreement  to  a  regulator  on  demand.  The  institution  requires  the  op-
erator  to  provide  collateral  (such  as  cash,  securities,  bonds  or  other  monetary  instru-
ments) in the amount of the letter of credit and also charges the operator for providing 
it. Regulators generally require letters of credit to be irrevocable. 

Self-provision: financial provision by the operator itself. This includes ‘provisioning in 
accounts’ and ‘self-insurance’. It is, in essence, a promise by an operator to cover their 
environmental  liabilities  when  required.  It  does  not  require  an  operator  to  set  aside 
money. Generally, self-provision is based on the operator’s demonstration of sufficient 

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financial  strength.  The  operator  must  generally  update  the  above  information  on  an 
annual or other regular basis. 

Parent  Company  Guarantee:  legally-binding  agreement  by  the  operator’s  parent 
company  or  another  affiliate  to  satisfy  the  operator’s  obligations  under  environmental 
law or an environmental permit if the operator fails to do so. As with self-provision, the 
information  must  generally  be  updated  regularly.  Also  as  with  self-provision,  a  parent 
company guarantee does not require the corporation to set aside funds. 

Secured Fund: money deposited by an operator with a third party (e.g. in a bank ac-
count) and legally secured so that it can only be used for the intended purposes. Ex-
amples include ‘escrow accounts’ and ‘trust funds’. A trust fund is a particular type of 
secured  fund  established  by  an operator and managed by a trustee for the benefit of 
specified beneficiaries, generally including the regulator. A variant of the secured fund 
is  a  cash  deposit  with  the  regulator.  Secured  funds  tend  to  be  used  for  foreseen  re-
sponsibilities and not for costs arising from a pollution incident. 

Mutual or Pool: a group financial provision arrangement that an operator can join and 
pay into and which will pay if the operator defaults on its obligations. Legislation some-
times  allows  a group of operators to satisfy financial provision requirements by mem-
bership in an approved mutual (sometimes called a pool). Acceptance into the mutual 
requires each member to provide evidence of a specified amount of financial provision, 
or to pay a specified amount into the mutual each year. Members must agree to pay up 
to a specified (or unspecified) amount if another member of the mutual fails to do so. If 
the  amount  of  such  payment  exceeds  the  monies  held  by  the  mutual,  an  additional 
drawing is made on its members. 

Charge on asset: mortgage/charge over a specific asset in favour of a regulator which 
can  be  triggered  if  an  operator  defaults  on  its  obligations.  It  is  commonly  taken  over 
premises. 

Common  FG  instruments  with  their  advantages  and  disadvantages  are  illustrated  in 
Table 1.  

Table 1: Mine Reclamation Financial Provision Instruments (MonTec, 2008; amended 
by the authors) 

Types 

Surety 
bonds 

Characteristics 
• Most heavily used instrument. 
• A premium is paid by the min-
ing company to the underwrit-
ing institution that is the guar-
antee. 

Advantages 
•  The cost of getting it is rela-

tively low. 

•  Cost associated with putting 
it are expensed as a tax de-
ductible item. 

•  Once in place only a mini-
mal amount of administra-
tion is required. 

•  Many ways of initiating and 
releasing bonds through 
phased implementation and 
phased release. 

Disadvantages 
• Often a Letter of Credit is re-
quired to back up the bond, 
which makes it more expen-
sive. 

• Its availability may be restrict-
ed by a company's credit and 
its environmental risk. 

• The full face value of the sure-

ty may be required. 

Cash Trust 
Funds 

• The funds must be structured 
in such a way as to give rea-
sonable assurance that suffi-
cient funds will be available to 
meet expected closure costs. 

• It is highly desirable that the 

income earned by the fund be 

•  The company has control 
over its fund since any sur-
pluses created, or earned 
should be returned to the 
company 

•  The company have the in-
centive to ensure sound 

• Uncertainty about the size of 
the fund in view of the long 
time frame involved; 

• If large amount is required a 
transition period is necessary 
to allow time to the company 
to build up the required FG. 

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Types 

Characteristics 
tax protected until it is with-
drawn company; 

Letters of 
Credit 

• Similar to a surety bond. 
• The content of a LC should 
reflect the terms and condi-
tions agreed between a com-
pany and the government with 
respect to a specific closure 
plan. 

Advantages 
management of the fund; 
•  Are more visible and often 
better understood by gov-
ernment and the public than 
other alternatives. 

•  Low initial cost (about 1% 
per annum of the face val-
ue). 

•  Cost associated with open-
ing a LC are expensed as a 
tax deductible item. 
•  Once in place only a mini-
mal amount of administra-
tion is required. 

Disadvantages 

• Issued by a bank and usually 
for a larger sum of money 
than originally estimated for 
closure. 

• The availability of a LC may 
be restricted by a company's 
credit and its environmental 
risk. 

• Issued for a period of one year 

- short-term solution for a 
long-term problem. 

• Reduction of the company 

borrowing power. 

Insurances  • Special form of surety bond. 
• The premium paid will be a 

function of the estimated clo-
sure cost with actuarial calcu-
lations to annual pay-out lev-
els and the total amount of the 
insurance. 

•  May require smaller up-front 
cash commitments than a 
cash trust fund. 

• Initial premiums may be very 
high to ensure substance of 
the insurance. 

•  Premiums would be tax de-

• In addition to premium 

ductible. 

•  Less administration is re-

quired than with a cash trust 
fund 

Self- 
guarantees 

• Also known as corporate 

• Financial instrument of choice 

for a mining company. 

guarantee or self- insuring. 
• Based on an evaluation of the 
assets and liabilities of the 
company and its ability to pay 
the cost of closure require-
ments. 

Mortgage  A mortgage is a property title (e.g., 

real estate) which the operator of 
a mine transfers to the 
competent authority in order to 
secure the performance of a pre-
determined closure and 
rehabilitation duty. As soon as the 
duty is fulfilled, the property title is 
transferred back to the operator. 

Cash de-
posit 

A mortgage is a property title (e.g., 
The amount required to cover all 
closure and rehabilitation costs is 
paid into a bank account 
accessible only by the govern-
ment. In case the mine operator 
defaults on its obligations, the 
government has immediate ac-
cess to the funds in the account 

• Easy to administrate 
• No cash outflow from compa-

ny 

• Cash is readily available for 
closure and rehabilitation 
• Investment-grade securities 
(treasuries) can be traded 
with minimal risk of liquidity 
• High public acceptance ("visi-

bility" of guarantee) 

• for small and junior mining 

companies, if they fail to meet 
the criteria of a bank 

• Can be dissolved only partly 

in case of need 

• Can be transferred into a 

pooled fund 

amounts there could be taxes 
and insurance brokerage fees. 
• A new, not well tested guaran-

tee instrument. 

• Require long history of finan-
cial stability and an annual fi-
nancial statement prepared by 
accredited accounting firm. 
• Gaining access to assets may 
be problematic in the case of 
firms facing bankruptcy. 

• Value of mortgaged property 
may change (lose) with gen-
eral market conditions 
• Administrative cost to gov-

ernment to liquefy mortgaged 
property 

• Discount on property value in 
case rapid liquidation is nec-
essary 

• Mortgage reduces ability of 
mining company to obtain 
loans 

• Significant capital is tied up for 
the duration of the mine life, 
especially for large mining 
projects 

• Some governments may be 

tempted to use the deposited 
cash for purposes other than 
securing the mining project 
• Cash is more vulnerable to 
being lost to fraud or theft 

Countries that already implemented a mine reclamation bonding system are the United 
States, Canada, Australia (Cheng & Skousen, 2017), Ireland (Environmental Protection 

43 

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Agency  of  Ireland,  Office  of  Environmental  Enforcement,  2014),  and  South  Africa 
(2015, 2018). Proven bond types are cash deposits, bank guarantees, insurances, and 
trust  funds  (Cheng  &  Skousen,  2017;  van  Zyl  et  al.  2012).  Cheng  (2009)  arguments 
that a desirable bonding system should form economic incentives rather than economic 
burdens for mining companies. For that reason, cash bonds are rare because high cost 
of  bonding  reduces  investment  in  and  by  the  mining  industry  (Cheng  &  Skousen, 
2017).  Cash  bonds  may  impose  liquidity  constraint  and  economic  burdens  on  some 
companies  and  are  usually  expected  when  the  financial  strength  of  the  company  is 
questionable, or the permit time is short (Cheng & Skousen, 2017). 

A combination of financial provisions may be used by operators to cover the full liability 
(Bradley et al. 2017). Examples of such scenarios are: 

•  covering foreseen liabilities with one financial provision (e.g. cash deposit) and 
unforeseen liabilities with another (e.g. environmental impairment liability insur-
ance) 

•  covering the gap with, for example, a financial institution guaranty, while a cash 

deposit is accumulating; and 

•  using a variety of insurance products to achieve full cover for unforeseen liabili-

ties 

2.1.3  Time Schedule for Establishing the Financial Guarantee 

The FG is requested in case of exploration and exploitation. Exploration is performed 
based on an exclusive license granted for any of the mineral resources. The evaluation 
of  environmental  rehabilitation  project takes into consideration: the works required for 
the protection and restoration / rehabilitation of the environment, funds allocated to the 
works  required  for  the  environmental  protection  and  rehabilitation,  correlation  of  the 
environment rehabilitation project with the proposed exploration program. 

The  exploration  license  is  granted  for  a  certain period (depending on country specific 
rules), provided a fee is paid in advance for the exploration activity and an appropriate 
FG for the environment rehabilitation is submitted, determined under the environmental 
rehabilitation project. The FG for environmental rehabilitation in case of an exploration 
license should to be deposited annually in the first month of the period covered, and is 
established within the license so that to cover for the environmental restoration works 
specified in the environmental rehabilitation project. 

2.1.4  Coverage of the Financial Guarantee 

A closure plan serves as base for regulatory body's determination of the FG amount. A 
FG reflects the cost of a mine closure and has to be adjustable, up or down, to reflect 
changes in the proposed closure plan. This cost will frequently be higher than the cost 
to the operator, because, in the event of a bankruptcy of the operator, the state will not 
be able to use site's mine production equipment and personnel, with resulting marginal 
cost (Hollands, 1999). Long-term commitments (e.g., monitoring, after care, etc.) have 
to be taken into account on a best-estimate basis, even though no clear official calcula-
tion methods exist. The other method to calculate the FG often applied by the surveyed 
companies is based on unit amount calculations (e.g., per t of mine wastes produced, 
etc.). FG must cover closure and post-closure activities. 

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2.1.5  Approach to Financial and Economic Analysis 

An  investment  requires  financial  and  economic  analysis,  two  approaches  that  serve 
two  different  purposes.  The  financial  analysis  is  used  to  document  a  reasonable  ex-
pected return on investment to prospective investors. The economic analysis is used to 
document that the project is a net benefit to society as a whole – this is especially in-
teresting in relation to public investments. The main traits of the financial and economic 
analysis respectively are: 

Financial Analysis: 

• 

Investor's perspective 

•  Based on market prices 

• 

Including taxes, tariffs, subsidies etc. 

•  Does not include externalities 

Economic Analysis: 

•  Society's economic perspective 

•  Applies  economic  prices  excluding  taxes,  tariffs,  subsidies  etc.  to  reflect  the 

value of the project to society. 

•  Externalities  (positive  and  negative)  are  included  and  quantified  in  monetary 

terms (such as reduction in GHG emissions). 

The  central  economic  concepts  are  briefly  introduced  which  are  essential  to  under-
standing financial and economic feasibility studies (FS). 

Interest Rates 

Interest  rates  are  a  central  element  in  financial  and  economic  analyses.  The  interest 
rate is the opportunity cost of capital, i.e. what is the expected return on investment. 

The return of a project shall be compared to the alternative return, given the money is 
invested elsewhere. Therefore, the appropriate discount rate for a financial assessment 
is the weighted average cost of capital often referred to as the WACC, that is calculat-
ed using following formula:   

WACC = Share of Equity × Cost of Equity + Share of Debt × After tax Costs of Debt 

where the corporate tax shield is deducted from the cost of debt. 

Economic/Social  Discount  Rate:  the  appropriate  discount  rate,  when  performing  an 
economic analysis is the rate of return of the entire economy, i.e., the national oppor-
tunity cost of capital. In comparison, the WACC applied in the financial analysis is only 
relevant to a specific investor, as the WACC calculation is based on a single investor´s 
cost of equity and debt. The economic discount rate is typically lower than the WACC. 

Interest  rates  are  very  important  to  economic  and  financial  FS,  as  they  enable  the 
comparison of costs and revenues at different points in time. 

Discounting and annuities 

Interest  rates  are  used  to  compare  payment  streams  today  with  payment  streams  to-
morrow. Such a comparison can employ one of two main methods: 

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•  Net Present Value 

•  Total Annual Net Cost 

These  methods  each  have  their  strengths  and  weaknesses.  The  Net  Present  Value 
method  is  good  for  keeping  track  of  cash  flow  and  variations  in  costs  and  revenues 
over time. The Total Annual Net Cost method is good for managing complex projects 
with many technical components with different technical life spans. 

Net Present Value 

On  some  projects,  revenues  and  costs  vary  over  time,  e.g.  up  front  investments  and 
revenues that fluctuate (in real terms) over time. In that case will be needed to use the 
Net Present Value method to calculate the difference between the present value of all 
future costs and the present value of all future revenues.  This method allows to keep 
track of cash flow, as the method requires to plot all costs and revenues over time. 

NPV: The Net Present Value is a measure of profitability used in corporate budgeting 
to  assess  a  given  project´s  potential  return  on  investment,  the  NPV  is  the  difference 
between the present value of cash inflows and the present value of cash outflows. Due 
to the value of the time, the NPV takes into account the discount rate (here the WACC) 
over the lifetime of the project, thus presenting the annual cash flows in present values. 

The interest rate applied for calculating the NPV is either the WACC or the economic 
discount rate. The NPV is calculated using the formula: 

where i is the financial discount rate (WACC), Ct the net cash flow at time t and N the 
total number of time periods.  

A NPV of zero (0) implies that the return on the investment equals the WACC. There-
fore, a negative NPV can be found for a project with a positive return, but where this 
return is lower than the investor’s required return. 

Total Annual Net Cost 

On  project  where  revenues  and  operating  costs  are  constant  over  time  it  may  be  an 
advantage  to  use  a  simpler  approach  than  NPV.  The  Total  Annual  Net  Cost  method 
annualizes  all  capital  costs  into  annual  payments  on  a  loan  with  either  WACC  or  the 
Economic Discount Rate as the interest rate. Since operating costs and revenues are 
identical from one year to the next it will be sufficient to calculate the sum of the annual 
payment on the capital investment, the annual operating cost and the annual revenue 
for a single year. This Total Annual Net Cost is directly comparable to other alternatives 
calculated in the same manner. 

This method is especially effective when there is a project that includes many technical 
components  with  different  technical  life  spans.  The  annual  payment  is  calculated  on 
each  component  separately,  and  based  the  payment  calculation  on  a  loan  with  the 
same duration as the technical life span. 

Key Indicators 

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When  one  or  more alternatives are compared, it is usually sufficient to directly match 
the Net Present Value or the Total Annual Net Cost in order to assess which project is 
the  better  alternative.  However,  in  many  cases  you  will  also  want  to  directly  assess 
whether the preferred alternative is economically and financially feasible. The primary 
indicator  of  this  is  simply  the  value  of  the  Net  Present  Value  or  the  Total  Annual  Net 
Cost.  A  positive  value  means  the  project  yields  a  net  surplus  –  and  a  negative  value 
means a net loss. In addition to this direct assessment of the value exists several ways 
to extract more detailed information on the profitability of a project. 

IRR: The internal rate of return is a measure used for assessing the profitability of po-
tential  investment.  The  internal  rate  of  return  is  the  discount  rate  that  makes  the  net 
present value if all cash flows equal to zero. 

DSCR: The debt service coverage ratio is the ration of cash available for debt servicing 
to interest, principal and lease payments. The DSCR is a measurement of an entity´s 
ability to earn enough cash to cover its debt payments.  

The higher this ratio is, the lower the risk of the lender. To be confident that the inves-
tor or project owner can repay his debt, financial institutions (lenders) will demand that 
the DSCR is larger than one (1) by a certain margin.  

Financial Analysis 

A  financial  analysis  estimates  the  profitability  of  a  project,  from  an  investor's 
perspective.  In  a  financial  analysis  are  compared  the  costs  of  the  project  to  the 
expected  revenue  over  the  project  lifespan.  This  includes  costs  of  financing  and 
taxes/subsidies. Figure 8 shows the approach to Financial Analysis. 

Figure 8: Approach to Financial Analysis (Legend: CAPEX: Capital Expenditure, 
OPEX: Operational Expenditure) 

The goal of the financial analysis is to demonstrate the ability of the project to generate 
a  sufficient  return  on  investment  to  be  interesting  for  investors.  The  results  of  the 
financial  analysis  are  typically  presented  as  the  Net  Present  Value  and  the  Internal 
Rate of Return. Investors will also be interested in the Debt Service Coverage Ratio to 
assess the financial risk of the project. 

Economic Analysis 

An  economic  analysis  takes  a  broader  view  of  the  profitability  of  the  project.  In  an 
economic  analysis,  you  include  external  effects  such  as  environmental  impacts  and 
health  impacts.  The  value  of  external  effects  is  typically  assigned  using  economic 
opportunity  costs  or  shadow  prices.  An  economic  analysis  does  not  include  taxes, 
tariffs, subsidies, etc. These costs do not add to economic productivity and are merely 
transactions between entities within the economy. 

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Figure 9: Approach to Economic Analysis 

An  economic  analysis  is  always  a  comparison  between  a  base  case  –  the  expected 
present  and  future  situation  without  the  project  –  and  the  project  alternative.  Without 
this comparison, it would be impossible to assess whether the external effects are an 
improvement  or  not.  Whenever  the  term  "benefit"  is  used  in  an  economic  analysis  it 
refers to the change in external effects that can be attributed to the project. 

The goal of the economic analysis is to demonstrate that the project is a net gain for 
society. This is typically mandatory whenever there is an element of public financing or 
regulation, e.g. tariffs. Economic analysis is also more and more frequently being used 
to brand private investments as being socially responsible. Typically, there is a greater 
variation  in  how  the  results  of  the  economic  analysis  are  reported  as  opposed  to  the 
financial  analysis.  The  financial  analysis  serves  a  very  specific  purpose,  whereas  the 
economic analysis is used to communicate the benefits of the project to many different 
stakeholders. 

2.1.6  Cost – Benefit - Analysis 

The assessment of the several remedial options for the mine objects is based on a cost 
benefit  analysis.  This  means  that  the  evaluation  of  whether  rehabilitation  actions 
should  be  undertaken  or  not  and  to  select  a  preferred  rehabilitation  option  with  the 
maximum effect in relation to the money spent and other potentially negative impacts. 
A scoring system is needed to assess the effects of each option. Each factor has the 
same  weighing  except  the  costs.  Following  factors  of  relevance  in  the  cost  benefit 
analysis are usually chosen: 

• 

Improvement  of  geotechnical  stability,  water-related  aspects,  air-related  as-
pects, and soil-related aspects 

•  Facilitation of beneficial after-uses 

•  Worker safety 

•  Sustainability, and  

•  Costs 

The options for all objects are compared through rating points. The total points will in-
dicate the preferred option (the higher the more preferred).  

2.1.7  Structure of Costing 

The structure of costing of closure activities comprises following basic cost types: 

Closure cost: 

• 

Investment and maintenance cost 

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•  Design, engineering and supervision cost 

•  Administrative cost (permits, fees and taxes) 

After-closure cost: 

•  After-closure and monitoring cost 

• 

Inspection cost 

It should be noted that costings associated with conformance checks, reviews, audits 
and safety evaluations as set out in the BREF for the Management of Waste from Ex-
tractive Industries must be included at all stages.  

Table 2 provides an overview on closure guarantee factors, illustrating which types of 
cost must be covered through the FGs.  

Table 2: Closure Guarantee Factors (after Legislative Audit Division, 1997; Mota de 
Lima, 2003; Cheng & Skousen, 2017; amended by the authors) 

Costs 
Direct closure costs  Calculated  using  conditions  which  represent  the  maximum 

Description 

closure cost. 

Indirect closure costs  Contract  preparation  and  administration  costs.  Calculated  by 

project staff and site specific. 
1 to 5 % of direct closure cost 

Mobilization  and  site 
preparation 
Contingencies 

Engineering 
Design 
Overhead 

and 

Project uncertainties and unexpected natural events, up to 30 
% of direct closure costs is possible. 
Redesign  to  reflect  current  conditions.  2  to  10  %  of  direct 
costs. 
Overhead not included in direct cost calculations, 3 to 14 % of 
direct closure costs. 
Project inspection and supervision, 2 to 7 % of direct closure 
costs. Administrative maintenance 

Operation  of  the  environmental  operation  system,  water 
treatment  etc.  Duration  and  cost  site  specific.  2  to  10  %  of 
direct costs. 
Environmental observation, duration and cost site specific. 

manage-

Closure 
ment 
Administrative costs  Permitting cost. Country and site specific. 
Maintenance costs 

Monitoring costs 

There is inherent uncertainty in costing closure and after-closure due to the complexi-
ties involved and lack of knowledge of the circumstances that will pertain at the time of 
closure. Therefore, the final costing should include a level of contingency. The contin-
gency  is  a  specific  provision  for  unplanned  or  unforeseeable  items  and  provides  an 
additional level of confidence in relation to the costing. The rate of contingency should 
reflect the level of uncertainty inherent in the costing.  

As  mentioned  in  table  2,  the  cost  to  be  considered  concern  engineering  and  design, 
direct  closure  costs,  indirect  closure  costs,  mobilization  and  site  preparation,  contin-
gencies,  closure  management,  administrative  costs,  maintenance  costs,  and  monitor-
ing costs including and overhead. Cost profiles in this GD consider engineering works 
and technical works. Cost-relevant activities are given in section 5. Initial costs of clo-

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sure, rehabilitation and after-closure should be adjusted to account for future inflation. 
The inflation rate used and justification for it should be provided by the permit holder. 

2.1.8  Costing: Investment and Maintenance Cost 

Construction costs represent investment costs as a price expression of the investment 
costs for a building. They are estimated as part of the construction planning. There are 
four  primary  methods  used  to  estimate  construction  costs  that  are  not  specified  in 
terms of application to a certain design level or in terms of determination of the relevant 
cost information (Xu et al. 2014):  

•  project comparison estimating 

•  area and volume estimating 

•  assembly and system estimating, and 

•  unit price and schedule estimating 

A unified model of these four methods consists of quantity and pricing (Xu et al. 2014), 
and  this  is  the  approach  that  is  typically  applied  in  closure  design  projects.  Scope  of 
the cost estimation is the net present investment value that must be supplemented with 
the  (future)  proofing  costs,  contingencies,  and  the  consideration  of  inflation  and  dis-
counting. The resulting value is the direct investment cost. Hence, in-order to define the 
scope  of  Work  (and  thereafter  to  prepare  a  cost  estimate)  following  details  are  re-
quired. 

1. Detail drawing 

2. Material Specification 

3. Standard of work man ship 

4. Method specification/ statement of the intended construction 

5. Time period 

6.  Reasonable  up  to  date  rates  applicable  for  various  trade  items.  Involved  with  con-
struction. 

A cash flow showing expenses and incomes must also be a part of the FS for the im-
plementation  of  the  mine. The cash flow should be linked to the staggering of invest-
ments,  the  exploitation  production  rate,  the  closure  and  rehabilitation  works  including 
post  closure  monitoring  and  maintenance.  Closure  and  rehabilitation  works  are  de-
signed, if technically possible, as much in parallel with the exploitation works. Dimen-
sional  characteristics  of  the  mining  elements,  as  they  are  at  the  time  when  the  entire 
reserve  has  been  extracted  according  to  the  mining  plan, including as build drawings 
for  all  constructions  and  utility  networks,  will  be  the  starting point in dimensioning the 
closure and rehabilitation works.  

The  various  positions  constituting  the  investment  will  correspond  to  all  expenses  and 
margins of the engineering company to carry out the project. The main items constitut-
ing the cost of the investment are generally the following: 

Project evaluation and cost estimation 

• 

the main equipment 

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•  secondary materials 

•  packaging and transportation 

•  construction work, including temporary site installations 

•  supply studies and start-up services 

•  specialized studies (topography, soil, hydrometry, noise, pollution ...) 

• 

financial expenses: deposits and known financial charges 

•  basic  insurance:  professional  liability,  transport  of  equipment  and  personnel 

start-up of construction site 

insurance 

the general expenses and the profit of the company 

• 

• 

All items must be supplemented by technical and unexpected provisions and the provi-
sions needed to cover inflation and foreign exchange risks over the life of the project. 
As the detailed and semi-detailed methods are based on contractual prices, there is no 
need to correct the final assessment by a location factor. To have a correct cost esti-
mate in the above presented context, detailed and semi-detailed cost estimation meth-
ods  should  be  used.  These  methods  are  based  on  the  definition  of  the  various  items 
constituting the investment. This definition is based on: 

• 

• 

the cost breakdown structure, itself based on the tasks to be performed to carry 
out the project and the required resources (work breakdown structure) 

the "cost code" or project account plan which is a categorical cost classification 
system 

The structure of this "cost code" is based on a logical cut of the construction project in 
controllable elements to meet the following two objectives: 

•  estimate of the investment 

•  control of the investment during the realization of the project. 

Firstly,  the  breakdown  of  costs  is  based  on  the  physical  decomposition  of  the  project 
(technical  chart).  The  principle  of  cost  splitting  makes  it possible to better identify the 
essential  elements  and  to  ensure  the  completeness  of  the  costing.  The  approach  is 
starting from the main installation to get to all its components. Maintenance expenses 
are the costs incurred to keep an item in good condition or good working order. When 
purchasing  an  item  that  requires  upkeep,  consumers  should  consider  the  initial  price 
tag as well as the item's ongoing maintenance expenses. 

2.1.9  Costing: Engineering and Supervision Cost 

Engineering and supervision cost comprise design and management activities that are 
necessary  to  develop  the  project  implementation  documentation.  Based  on  technical 
dimensions,  mandatory  technologies  and  materials  specification  in  the  above-
mentioned conditions the cost of closure and rehabilitation works can be evaluated.  

The  objective  of  the  cost  estimate is to produce, depending on the project's progress 
phase,  information  to  establish  the  project  budget.  The  project  estimation  methods 

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used depend on the project's progress phase. As a result, the choice of an estimation 
method depends on the level of information available. Table 3 shows the cost estima-
tion levels during the design process. 

Table 3: Cost estimation levels during the design process 

Initial / concep-
tual studies 

Budget 
Categories 
Estimation 
method 

Budget "order of 
magnitude" 
Global method 
or similarity 

Level 
precision 

of 

40 to 50 % 

Feasibility 
studies 
(FS) 
"Preliminary" 
budget 
Modular meth-
od or factor 
method 
25 to 30 % 

Basic studies: 
project design 

"Goal" budget 

Semi-detailed 
method 

Project devel-
opment / de-
tailed design 
Initial or con-
tractual budget 
Detailed meth-
od 

15 to 20 % 

5 to 10% 

Engineering cost include further design, engineering and supervision cost. The starting 
point in calculating the FG would be the TD for restoring the environment affected by 
mining  activities  and  the  Bills  of  Quantities  (BoQ)  for  the  environmental  rehabilitation 
works. The TD for mine closure should be based on the elements presented and esti-
mated  in  the  preparation  of  FS  and  TD  based  on  which  the  capital  works  are  per-
formed. Still compared to the FS mine closure cost estimate, the FG value should con-
sider that decommissioning and rehabilitation works will be performed by independent 
and properly qualified third parties so additional cost chapters (compared to the situa-
tion where is considered that the mining operator will do the mine closure and rehabili-
tation works by itself or under own management) should be included: 

•  Obtaining endorsements, approvals, permits  

•  Design and engineering (compared to the technical design prepared at the be-
ginning of the mining objective, the re-designing of the closure and environment 
rehabilitation  works  will  be  usually  required  in  order  to  correlate  them  with the 
status  of  the  objective  at  the  moment  of ceasing the activity  and given the re-
quirement  of  implementing  technical  solutions  adjusted  to  possible  new  tech-
nical standards and regulations approved meanwhile.  

•  Organizing the procurement procedures 

•  Consultancy 

•  Technical assistance 

In order to be able to physically build the mining project’s elements there is a need for a 
detailed design. Project design will serve as input to the development consent applica-
tions  and  will  be  assessed  in  an  Environmental  impact  assessment  (EIA)  process  if 
required. 

In  order  to  establish  a  correct  FG  value  that  should  cover  the  mine  decommissioning 
and  rehabilitation  cost  including  post  closure  monitoring  and  maintenance,  there  is  a 
need for a calculation methodology which is a) high enough to be sure that in the case 
of bankruptcy the tax payer does not need to step in, but also b) low enough in order to 
attract  investment.  The  outcome  of  the  designed  decommissioning  and  rehabilitation 
works must match the post-mining land use(s) that has been proposed/agreed with key 

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stakeholders including regulators. The design for closure and rehabilitation works must 
follow all applicable standards and norms that will impose technical dimensions, man-
datory technologies and materials specification. 

2.1.10  Plausible Worst Case Scenario 

It is to be underlined that the FG function is not to cover the consequences of accidents 
and  incidents,  as  these  are  unforeseen  liabilities.  The  plausible  worst  case  scenario 
refers to the plausible event that poses the maximum environmental liability in the case 
of foreseen liabilities, i.e. consequence, during the period to be covered by the financial 
provision (Environmental Protection Agency, 2014). A worst-case scenario is a concept 
in risk management wherein the planner, particularly in planning for potential disasters, 
considers the most severe possible outcome that can reasonably be projected to occur 
in a given situation. In case of FG establishment for mine closure this topic is particu-
larly relevant in terms of provision for premature closure. The plausible worst case sce-
nario may be represented by the risk with the highest consequence rating. 

Although practical planning for premature closure (permanent or suspended operations 
under care and maintenance) may not be done in detail in the early stages of the pro-
ject, consideration must be given in the Mine Closure Plans for how a proponent plans 
to  deal  with  these  closure  scenarios  which  may  arise  from  economic,  environmental, 
safety or other external pressures (Department of Mines and Petroleum, 2015). In such 
an  event,  an  accelerated  closure  process  will  need  to  be  implemented.  In  particular, 
this  should  include  confirmation  that  appropriate  materials  are  available  on  site  and 
contingencies  are  provided  to  make  landforms  such  as  tailings  storage  facilities  and 
mine waste heaps secure and non-polluting/ non-contaminating in the event of prema-
ture closure (Department of Mines and Petroleum Australia, 2015). The dimensions of 
premature closure must be considered during the closure design already, based on a 
risk assessment. 

To assess the risk, the source – pathway - receptor model might be used. The model 
starts with the risk source and the pathway how the hazard can reach through the envi-
ronment. Finally, it is considered how the receptor of the hazard is affected. A receptor 
can  be  human  and/or  environment.  Usually  for  each  source,  there  are  multiple  path-
ways and receptors. After identification of the sources, the pathways and the receptors, 
the next step is the assessment of the impact of the risk or hazard to the receptor with 
respect to the following parameters: 

•  Spatial extent of the impact 

•  Temporal extent of the impact 

•  Severity of the impact. 

The  significance  of  the  impact  is  calculated  by  multiplying  the  assigned  values  for 
magnitude  of  the  potential  impact  and  the  sensitivity  of  the  receptor  to  generate  an 
evaluation matrix. The risk matrix according to Nohl & Thiemecke (1988) is a common 
methodology for technical risk assessment. These two elements of a risk can be pre-
sented in a matrix that allows risks to be categorised by different qualitative risk clas-
ses. The aim of the matrix is to estimate the risk significance (figure 10). The severity of 
impacts  is  ranked  according  to  the  following  qualitative  scheme  that  is  based  on  the 
sensitivity  of  receptors  and  magnitude  of  impacts.  When  determining  impact  magni-
tude, conservative assumptions are often used. 

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Sensitivity of Receptors 

1 

Low 

2 

3 

Medium 

High 

Magnitude  

of the impact 

1 

2 

3 

Minor 

Negligible 

Minor 

Moderate 

Moderate 

Minor 

Moderate 

Major 

Major 

Moderate 

Major 

Critical 

Figure 10: Risk Evaluation Matrix according to Nohl & Thiemecke (1988) 

The most sensitive facility in terms of the plausible worst case scenario is a dam failure 
of the TMF that can lead to the spreading of tailings material. Santamarina et al. (2019) 
argue that given the number of tailings facilities worldwide (over 9000), there is an ur-
gent  need  to  gain  a  better  understanding  of  the  mechanisms  of  tailings  dam  failures, 
and  to  use  this  understanding  to  improve  management  practices.  Figure  8  illustrates 
potential  TMF  failure  mechanisms  that  must  be  considered  during  the  Technical  De-
sign.  There  must  be  taken  precaution  indicator  during  the  design  to  avoid  TMF  dam 
failure, that are: 

• 

• 

• 

• 

the  impoundment  must  be  stable  under  all  static  and  transient  loads;  for  that 
must be identified failure modes 

the  impoundment  must  be  stable  for  seismic  loading  and  must  pass  design 
flood 

the transient load design magnitudes must be sufficient 

the surface and groundwater quality must meet regional and global water quali-
ty standards 

To analyse the physical stability in the short and long term according to Eurocode 7–1 
(EN 1997-1:2004 - Part 1) or equivalent national standards and to the provisions of the 
ICOLD guidelines (including Bulletin 139 and 148) or equivalent national standards in 
the case of large dams. 

It is essential for the stability and or integrity of a TMF to manage decant pond water, 
the combination of supernatant and runoff. The starting point for good management is 
an  integrated  water  balance  model  that  will  allow  the  prediction  of  the  water  volume 
needed to be managed (figure 11).  

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Figure 11: Potential TMF failure mechanisms (ATV-DVWK-M 503) 

The main hazards in terms of potential TMF failure mechanisms are: 

Foundation instability: 

•  collapse due to mine subsidence allows tailings to escape into mine or void;  

•  sliding on weak soil or liner interface 

•  compression of weak soils leads to cracking of dam 

•  construction pore pressures rise and foundations move 

•  seepage through a poor membrane or pervious soils into groundwater system, 

bypassing seepage recovery systems 

•  seismic liquefaction of foundations 

•  seismic deformation of foundations 

•  non-seismic liquefaction of foundations 

Structural failures: 

•  piping around a culvert or decant pipe 

• 

reclaim tower fails 

•  pumps fail due to loss of power 

•  pipeline or conduit fails 

• 

landslide blocks spillway 

Without  prejudice  to  other  Community  legislation,  and  in  particular  Directives 
92/91/EEC and 92/104/EEC, MS have to ensure that major-accident hazards are iden-
tified  and  that  the  necessary  features  are  incorporated  into  the  design,  construction, 
operation  and  maintenance,  closure  and  after-closure  of  the  waste  facility  in  order  to 
prevent  such  accidents  and  to  limit  their  adverse  consequences  for  human  health 
and/or the environment, including any transboundary impacts. Article 6 “Major accident 
prevention and information” of the Directive 2006/21/EC shall apply to waste facilities, 
save for those waste facilities falling within the scope of Directive 96/82/EC (The Seve-
so II Directive). 

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According to article 6 of EWD each operator must, before the start of operations, draw 
up a major-accident prevention policy for the management of extractive waste and put 
into  effect  a  Safety Management System, implementing it in accordance with the ele-
ments set out in the Directive (Section 1 of Annex I). The document is intended to give 
an overview of how the operator ensures a high level of protection for people and envi-
ronment. As part of that policy, the operator must appoint a safety manager responsible 
for the implementation and periodic supervision of the major-accident prevention policy. 
During the design, extraordinary meteorological situations, particularly forecasts of 100 
and 1000 years rain events must be taken into account. 

However,  the  Safety  Management  System  does  include  the  procedures  necessary  to 
ensure  that  an  adequate  Internal  Emergency  Plan  is developed, adopted, implement-
ed,  reviewed,  tested,  and  where  necessary  revised  and  updated,  specifying  the 
measures to be taken on site in the event of an accident. The procedures should also 
cover the necessary arrangements for communication of the plans to all those likely to 
be affected by an emergency. Best Practice is an integrated risk management and the 
implementation of a Risk Management System According to ISO 31000:2018. 

2.1.11  Content of Technical Design 

The  TD  for  environmental  rehabilitation  shall  be  drawn  up  in  compliance  with  the  re-
spective  legislation.  It  must  be  based  on  a  comprehensive  risk  assessment.  The  FG 
cannot be lower than the total value of the environment rehabilitation works provided in 
the  TD  for  environment  rehabilitation,  namely:  (i)  the  value  of  the  works  for  restoring 
the environment affected by mining works planned for the next guaranteed period, and 
(ii) the value of outstanding works or of the works not properly carried out for the reha-
bilitation of the environment affected as a result of mining works performed to date. Any 
changes made to the development-mining TD or to the exploration works design shall 
be accompanied by the appropriate updating of the Technical Design for environment 
rehabilitation,  and  the  updated  version  will  be  considered  only  after  all  the  required 
endorsements, approvals and permits are obtained according to the applicable legisla-
tion. Following specific issues shall be considered in the TD: 

General information on the mining facility: 

•  administrative – territorial location 

•  access in the area 

•  surface morphology 

•  geology of region and ore body 

•  status of resources / reserves 

General presentation of the mining facility: 

•  description of the mining works program 

•  current status of the mining works 

•  mining works planned for the next period 

•  planned decommissioning works 

•  status of land as at the date of drafting the study and at the end of the period 

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Environment deterioration generated by the mining activity;   

•  stability of the land surface, of the open pit slopes and embankments 

• 

land degradation caused by excavation, waste disposal, soil stripping, etc. 

•  pollution of buildings, plant and equipment 

•  pollution of surface and underground aquifer layers 

Degradation of water quality due to emissions of dust, exhaust gases, etc.: 

•  deterioration of vegetation (deforestation, soil stripping, etc.) 

Environmental rehabilitation works: 

•  works for stabilizing the natural slopes and open pit/mine waste heap embank-

ments 

•  placing  back  of  extractive  waste  into  excavation  voids  and  filling  back  other 

wastes for recovery works 

•  works for environmental rehabilitation of tailings ponds and/or decant dams 

•  water management (collection, drainage, wastewater treatment, discharge) 

• 

• 

land decontamination works 

land consolidation works 

•  works for restoring the vegetation (planting, grassing) 

•  other works required 

Physical volume and value of environment rehabilitation works: 

• 

lists of works to be carried out and quantities required 

•  unit costs by categories of works 

• 

• 

total costs of the environment rehabilitation works 

funding sources for the environment rehabilitation works 

Schedule of the environment rehabilitation works; 

•  carry  out  the  environment  rehabilitation  works  in  correlation  with  the  mining 

works schedule 

•  phases for carrying out the environment rehabilitation works 

Monitoring: 

•  objectives of the monitoring program 

•  estimated period of the monitoring works 

•  maintenance and/or rehabilitation works 

•  costs of the monitoring works 

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2.1.12  Bills of Quantities  

Base of the cost estimates are the Bills of Quantities (BoQ). BoQ is a document pre-
pared  by  the  cost  consultant  (often  a  quantity  surveyor)  that  provides  project  specific 
measured quantities of the items of work identified by the drawings and specifications 
in  the  tender  documentation.  Figure  12  provides  a  simplified  sample  of  a  BoQ.  The 
quantities may be measured in number, length, area, volume, weight or time. Preparing 
a BoQ requires that the design is complete and a specification has been prepared. The 
BoQ is issued to tenderers for them to prepare a price for carrying out the works. 

Bills of Quantities 
Environment Rehabilitation Works provided in the Technical Design 

M.U. 

2 

Quantity 

Unit Price 

Total Value 

3 

4 

5 

No. 

Item 

1 

0 
1.  Works in the area affected by mining 
1.1  Depositing soil on berms and compacting 
1.2  Planting shrubs 
1.3  Maintenance Works 
......................... 
..... 
2.  Works in the area of tailings stockpiles 
2.1  Organizing the area 
2.2  Covering the land with mesh  
2.3  Transportation of topsoil 
2.4  Fertilisation 
2.5  Grass sowing 
2.6  Maintenance 
..... 
3.  Other  works  for  environment  rehabilita-

............................. 

tion 
............................ 

..... 

TOTAL 

Figure 12: Simplified sample of a BoQ 

2.1.13  Cost Profile and cost-relevant activities 

The  GD  summarizes  the  technical  steps  for  a  closure  that  is  safe  in  the  long  term.  It 
contains the cost-relevant activities for the respective closure activities. 

2.1.14  Periodic Adjustment of the Financial Guarantee 

According  to  Article  14(3),  the  FG  size  has  to  be  adjusted  periodically  in  accordance 
with any rehabilitation work needed as described in the waste management plan. Pur-
suant  to  Article  5(4)  of  the  Directive,  the  EWMP  must  be  reviewed  every  5  years,  or 
more frequently in case of substantial changes of the operations. According to Article 
7(4),  competent  authorities  have  to  reconsider  and,  where  necessary  update  permit 
conditions in case of substantial change of the operations, or on the basis of monitoring 
results, or in case of important modification of the Best Available Techniques. 

Any changes in TD or Exploration Works Design shall be accompanied by the appro-
priate updating of the Environment Restoration Technical Design (ERTD). The update 
will be considered only after all endorsements, approvals and permits are obtained. A 
modification of the general cost estimate related to the TD for environmental rehabilita-
tion shall implicitly lead to the FG modification. The ERTD shall highlight the values for 
the environmental rehabilitation at the end of each exploitation/exploration year, under-
lining the balance between the additional rehabilitation works associated with any new 

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exploration/exploitation  impact  generating  works  and  the  environment  rehabilitation 
works  forecasted  for  each  of  the  next  years  during  the  lifetime  of  the  mining  facility. 
Therefore, after the reception of the environmental rehabilitation works for the previous 
year, the value of the FG shall be adjusted. The annual FG amount update is also nec-
essary  because  of  potential  price  changes.  The  FG  shall  be  constituted  and  updated 
respectively,  prior  to  the  commencement  of  works,  namely  in  the  12th  month  of  each 
exploration/exploitation year, based on the values determined in the ERTD and on the 
documents confirming the carrying out of environmental rehabilitation works. 

a) 

Initial FG Assessment  

The  FG  amount  will  result  from  the  cost  estimate  of the ERTD. For the calculation of 
the amount software might be used which includes a data base with all the Cost Esti-
mate Norms and is easily updated with materials and norms required by the new con-
struction technologies. 

b) 

Verification Methods 

In  order  to  verify  the  value  correctness,  it  is  necessary  to  check  the  compliance  be-
tween sizes and specifications from drawings and bills of quantities, and subsequently 
with  works  cost  estimates.  Price  verification  can  be  conducted  using  a  software  with 
updated prices. 

c) 

FG Periodic Adjustment  

The time period for FG periodic adjustment might be adapted in case of lower risk and 
likelihood  of  environmental  consequences  (In  analogy  to  The  World  Bank  Group  Oil, 
Gas and Mining Policy Division, 2008). In case of a medium risk and likelihood of envi-
ronmental consequences the periodic adjustment might be conducted every 3 years, in 
case of a low risk and likelihood of environmental consequences every 6 years. 

2.1.15  Quality Management due to ISO 9001:2015 

Quality  management  of  the  closure  design  and  implementation  process  plays  a  sub-
stantial role and comprises two parts: 

Quality assurance during the design process 

•  design verification, and  

•  establishment  of  a  Quality  Assurance  Plan  (QAP)  as  part  of  the  design  docu-
ments. The QAP contains the requirements for the material testing (at least soil 
mechanics and chemistry), that is parameter sets and the analysis procedures 
requirements.  Analytics  has  to  be  performed  by  a  lab  accredited  according  to 
DIN EN ISO/IEC 17025.  

Quality assurance during the implementation process 

•  Comprises implementation verification and field testing 

• 

implementation  verification  is  performed  by  an  independent  certified  assessor. 
Following  levels  of  independent  implementation  verification  is  performed  in 
practice: 

o  Prefabrication of materials / components / systems 

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o  Self-monitoring of the manufacture by the manufacturer 
o  External monitoring of the construction by a commissioned third party 
o  Construction on the construction site 

  Self-examination of the executing construction company 

  External  inspection  by  a  commissioned  third  party  (commis-
sioned by the client), which must be confirmed by the competent 
authority 

o 

Inspection by competent authority 

2.2  Financial Guarantee Implementation 

FG must be complemented by permitting, inspection, enforcement and education pro-
cess  to  be  effectively  implemented.  The  permitting  process  is necessary for clarifying 
the  criteria  for  mine  closure,  impelling  planning  for  closure  from  the  outset  of  mine 
planning  and  successfully  ensuring  enforcement  of  closure  criteria.  The  enforcement 
capacity of the regulator should be clearly and explicit defined since it allows all parties 
involved to be aware of the FG implications in case of permit violations or bankruptcy. 
Inspections  require  good  communication  between  mining  companies  and  regulators 
with the goal of identifying faults in the previous closure plan and problems during their 
formative stages (Anderson, 1999). 

2.3  Review and Release of the Financial Guarantee 

The FG amount and the appropriateness need to be reviewed periodically. FG review 
is  mostly  done  annually or bi-annually. In some countries the review is undertaken at 
any time on request of the State Mining Authority, as it is the case in Poland. In Finland 
the  review  is  carried  out  only  in  the  case  the  permit  is  updated (after 9 years) and in 
Greece every 5 years. The FG release shall depend on the waste facility liability period 
described in the Mine Closure Plan, which also regulates how and when the FG has to 
be released. Only after approval of the plan by the competent authority the FG will be 
released.  The  process  might  be  supported  by  the  review  and  approval  of  an  external 
auditor stating that all closure and rehabilitation measures have been finalised accord-
ing to best practice and to the closure plan, and that no further hazard exists.  

FG  shall  be  released  only  to  the  holder  regardless  the  changes  occurred  during  the 
lifetime of the facility. In order to have the FG released, the operator, after full comple-
tion of the environmental rehabilitation works provided in the TD, shall submit an appli-
cation to the competent authority. This shall be accompanied by documents confirming 
the  carrying  out  of  environmental  rehabilitation  works  in  accordance  with  the  ERTD 
provisions. After the completed closure was approved by the competent authorities, the 
end of site ownership by the mining company and of their responsibility for the site, with 
transition of ownership and residual liability to the jurisdictional authority or a third party 
can be established (relinquishment). 

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a) Formalities regarding FG release  

Within 30 days from submitting the application on releasing the guarantee and related 
proving documents, the competent authority shall send a written response to the opera-
tor,  either  positive  or  negative.  During  the  evaluation  period  the  competent  authority 
shall conduct, through its territorial representatives, the verification on site of the envi-
ronmental rehabilitation works carried out and draw up a verification report.  

b) The case when the exploration/exploitation title is transferred to another mining op-
erator. 

In case of changing the mining operator within one perimeter, FG obligations shall be 
taken over by the new operator. 

c) The way rehabilitation works are to be carried out in case the mining operator goes 
bankrupt.  

In case the mining operator fails to meet its obligations on environmental rehabilitation, 
the  competent  authority  shall  commence  the  tender  procedure  for  the  environmental 
rehabilitation  works  based  on  the  Technical  Specifications  within  the  ERTD.  The  pro-
cedure  will  be  followed  in  accordance  with  the  legislation  in  force  on  public  procure-
ment. The amounts required for the tender procedure and funding all the expenses for 
the environmental rehabilitation works provided in the General Cost Estimate shall be 
funded  by  the  competent  authority  out  of  the  environmental  rehabilitation  guarantee 
submitted. 

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3.  Part B: Best Practices for Closure, Rehabilitation and After-closure De-

sign 

Closure cost must also cover engineering cost, particularly closure design cost, and in 
this way must be included into the FG. For this reason, also best practices for closure, 
rehabilitation and after-closure design are included into the GD. 

3.1  Combined Closure, Rehabilitation and After-closure Plans 

The  closure  of  mining  sites  requires  a  combined  approach  of  decommissioning  and 
rehabilitation,  laid  down  in  a  closure  plan.  However,  the technical closure strategy in-
cluding the closure options to be taken into consideration does substantially depend on 
the after use scenario. Depending on the mining typology, following closure approach-
es can be distinguished. 

•  Closure after termination of mining 

•  Closure in parallel to mining (progressive closure). 

After-closure plans refer to the closed mine that undergoes monitoring and inspections 
for  a  certain  period  that  is  determined  by  the  competent  authority.  In  analogy  to  the 
Environmental Protection Agency of Ireland (2014), the closure plan shall include, as a 
minimum, the following: 

•  a scope statement for the plan; 

• 

the  criteria  that  define  the  successful  decommissioning  of  the  activity  or  part 
thereof, which ensures minimum impact on the environment; 

•  a programme to achieve the stated criteria; 

•  where  relevant,  a  test  programme  to  demonstrate  the  successful  implementa-

tion of the decommissioning plan; and 

•  details of the costings for the plan and the FG to underwrite those costs. 

The closure plan must be validated through a final validation report in order to achieve 
a certificate of completion for the closure plan  that shall be emitted by the competent 
authority  (CA)  within  a  certain  period.  For  closure  in  parallel  to  mining,  that  typically 
takes  place  for  lignite  open  cast  mining,  milestones  must  be  defined  over  the  whole 
operation  period  of  several  decades  in  order  to  already  dismiss  parts  of  the         
recultivated  land  to  the  public.  If  closure  after  termination  of  mining  takes  place,  the 
closure plan must be submitted to the CA together with the application for exploration 
to  provide  the  complete  necessary  data  to  allow  the  CA  the  assessment  of  all  cash 
flows  for  operation  and  closure  for  a  comprehensive  assessment  of  a  sustainable  fi-
nancing plan.  

3.2  Definition of the Rehabilitation Scope and Resulting Closure Steps  

The main goal of rehabilitation is to return affected areas as near as possible to their 
economic and ecological value. It does not aim to return them to original state (UNEP, 
1983).  The  EWD  defines  as  overall  rehabilitation  scope  the  “treatment  of  the  land  af-
fected  by  a  waste  facility  in  such  a  way  as  to  restore  the  land  to  a  satisfactory  state, 

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with  particular  regard  to  soil  quality,  wild  life,  natural  habitats,  freshwater  systems, 
landscape and appropriate beneficial uses”. 

The  rehabilitation  scope  depends  on  the  level  of  potential  pollution  resulting  from  the 
mining activities and the requirements for the geotechnical long terms stability. Already 
during  the mining operation, an estimate or preliminary soil and water quality assess-
ment is needed to determine whether soil or water are contaminated and, where appli-
cable, to define the scope of the rehabilitation work. The characterization must:  

a)  determine  the  contamination  level;  depending  on  the  future  use  of  the  mining 

site 

b)  find the precise location of the contamination and determine whether and where 

it is spreading;  

c)  determine the volume of each type of contaminant. 

If a need for rehabilitation has been identified, the development of a suitable technolo-
gy for the rehabilitation of the mining legacy sites needs to be based on state of the art 
technologies. The aims of these technologies are: 

• 

• 

• 

• 

to  exclude  existing  acute  dangers  or  comparable  unacceptable  risks  from  the 
objects to human health and safety; 

to  create  long  term  stable  site  conditions  for  existing  piles,  former  operational 
areas and underground facilities; 

to interrupt the pathway for the transfer of pollutants to human beings; 

to minimize the impact of the objects to the environment. 

The  rehabilitation  techniques  shall  be  economically  and  technically  feasible.  The  clo-
sure plan involves the consideration of (Düzgün & Demirel, 2017): 

1.  Land use prior to mining and natural and cultural factors affecting the land use, 

2.  Land capability prior to mining, to support a variety of uses, 

3.  The alternatives for land use after completion of mining and rehabilitation 

4.  A  detailed  description  of  how  the  proposed  post-mining  land  use  is  to  be 

achieved 

5.  Methods  for  ensuring  that  mining  and  rehabilitation  operations  are  in  line  with 

declared land use plans and programs 

6.  Mining methods used to ensure that closure plan is compatible with local physi-

cal, environmental and climatic conditions, 

7.  The economic and technical feasibility of the closure plan, and 

8.  The current mining and regulatory conditions. 

The assessment of closure alternatives is not only a requirement for the assessment of 
economically efficient solutions, but also a regulatory requirement of the European en-
vironmental  legislation,  particularly  the  requirement  for  Environmental  Impact  Assess-
ment (EIA). If EIA is required, it can be seen from the Annex I of the newly amended 
EIA  Directive  2014/52/EU.  GD  Annex  1  provides  a  correlation  between  the  annex  of 

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the  EIA  Directive  with  the  formalities  of  the  codes  of  the  Statistical  Classification  of 
Economic Activities in the European Community (commonly referred to as NACE).  

3.3  Definition of After-closure Options 

Extractive activities create changes to topography with ongoing potential to impact the 
environment long after a extraction activity has ceased. The restored landscape can be 
designed as: 

•  agricultural land, field or meadow, including fisheries and gardening 

• 

forest 

•  biotope and greenfield including left to natural succession 

•  wetland 

•  waste disposal site (for instance preparation and operation as landfill) 

•  waste disposal site 

•  culture and recreation 

•  military facilities 

• 

industry and infrastructure. 

Even ore mining sites require often large rehabilitation efforts, Kivinen (2017) reported 
a  variety  of  documented  after-closure  uses  for  closed  mining  in  Finland  that  illustrate 
the general options:  

Mining sites in general: cultural heritage site of national significance, outdoor recrea-
tion,  nature  trail,  holiday  village,  museum,  dive  site,  swimming,  disc  golf  course, 
sand/gravel pit, bus scrapyard, concrete element factory, military facilities, and fire res-
cue exercises.  

Rehabilitated  TMFs:  Birdwatching,  concentration  of  ore,  military  facilities,  motorsport 
venue, airport (light aircraft), raw materials research, rally/dirt biking track, sand/gravel 
pit,  shooting  range,  unofficial  landfill,  golf  course,  waste  water  treatment  plant,  grey-
hound racing, waste facility of a potato processing factory, temporary parking lot.  

Waste rock facility: Off-road driving, construction material. 

Water-filled open pit: dive and swimming site, concerts. 

Underground mine: museum, research site on mine water treatment. 

Buildings: Restaurant; concentration plant, school, museum, engineering works, mili-
tary battle training, observation tower, sawmill, protected building, cultural events, rail-
way vehicle manufacturing, lighthouse, warehouse, offices, mushroom cultivation.  

Figure 13 illustrates some after-closure options in practice. The figures show: above - 
after-closure  as  mining  museum  and  underground  teaching  and  research  site  in 
Freiberg (Germany), Centre – after-closure use as swimming and diving site Blue La-
goon  in  Gotland  (Sweden).  Below  –  after-closure  use  as  hotel  and  recreation  area  in 
post-industrial atmosphere at a former limestone quarry in Gotland (Sweden).  

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Figure 13: After-closure options in practice 

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3.4  Design of a Closure Plan 

3.4.1  General Approach  

Closure  plans  leave  mine  and  TMF  site  in  an  acceptable  condition  ensuring  public 
health and safety, minimising the risk of contamination and, where possible, allow pro-
ductive  use  of  the  land  or  creates  a  stable  environment.  Best  Practice  in  staged  ap-
proach as risk-based closure process (Department of Mines and Petroleum at the Envi-
ronmental Protection Agency Australia, 2015) that includes: 

• 

Identifying a range of closure scenarios commensurate with risk 

•  Early identification of potential risks to successful closure 

•  Development of acceptable and realistic criteria to measure performance 

•  Orderly, timely and cost-effective closure outcomes 

•  Reduced uncertainty in closure costs; and 

•  Continual  improvement  in  industry  rehabilitation  standards  (e.g.  cover  design, 

and management of contaminated drainage, erosion and seepage) 

Figure 14 illustrates the integrating stages of mining and mine closure plan. 

Figure 14: Integrating stages of mining and mine closure plan (Department of Mines 
and Petroleum at the Environmental Protection Agency Australia, 2015) 

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For the integration of mining and mine closure plan, following planning steps are nec-
essary (Düzgün & Demirel, 2017):  

• 

Inventory of the pre-mining conditions 

•  Evaluation and decision on the post-mining requirements of the area consistent 

with the needs and requirements of the local communities 

•  Analysis of alternative mining and rehabilitation schemes to determine best al-

ternatives that meet the overall objectives  

•  Review of the rehabilitation experience at neighbouring mines or at mines oper-
ating  in  similar  conditions  to  determine  successful  rehabilitation  practices  and 
parameters, and  

•  Develop  an  acceptable  mining,  rehabilitation  and  land  use  scheme  to  be  inte-
grated  with  existing  technical,  social,  environmental,  political  and  economic 
conditions 

In the European Union exist since a few years, special requirements for the installation 
of  certain  industrial  activities,  among  them  the  energy  industries,  production  and  pro-
cessing  of  metals,  and  the  mineral  industry  regarding  the  inventory  of  the  pre-mining 
conditions.  Directive  2010/75/EU  on  industrial  emissions  (IED)  applies  an  integrated 
environmental  approach  to  the  regulation  of  certain  industrial  activities  (Part  A  activi-
ties). Where the activity involves the use, production or release of relevant hazardous 
substances, and having regard to the possibility of soil and groundwater contamination 
at  the  site  of  the  installation,  under  Article  22(2),  operators  are  required  to  submit  a 
baseline  report  (that  fulfils  the  requirements  of  the  inventory  of  the  pre-mining  condi-
tions). The aim of the IED Baseline Report is primarily the assessment of the soil quali-
ty at the start of the renewal of the permit of an industrial activity as to establish an ini-
tial state. The objective is to provide a basis for comparison upon definitive closure of 
the  activity,  as  to  make  possible  the  application  of  the  “polluter  pays  principle”  on  an 
objective basis. 

3.4.2  Structure of a Closure Plan – Design for Closure 

In order to help ensure the short-term and long-term structural stability of the extractive 
waste deposition area1, BAT is to use the following technique (MWEI BREF): 

Design for closure - Relevant for ponds, dams and heaps (permanent and temporary) 

•  a preliminary identification of the covering techniques; 

•  a  preliminary  identification  of  the  techniques  to  prevent  and  control  water  and 

wind erosion; 

•  an assessment of costs related to the proposed and alternative closure strate-

gies including a cost benefit analysis; 

1  The  MWEI  BREF  defines  waste  deposition  area  as  „Any  area  under  the  responsibility  of  an 
operator  where  extractive  waste  is  handled,  treated,  accumulated  or  deposited  whether  in  a 
solid or liquid state or in solution or suspension. This includes, but is not limited to, Extractive 
Waste Facilities, excavation voids where extractive waste is placed back, and areas for tempo-
rary storage of extractive waste.” 

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•  an Environmental Risk and Impact Evaluation; 

•  a specific indication of the closure process to be followed, specifying if the re-
habilitation will be progressively carried out during the operation phase or when 
progressive rehabilitation is not possible, it will be entirely carried out in the clo-
sure phase; in the latter case, the initial closure and after-closure planning ex-
plicitly states if a dry or wet cover will be implemented and provides details on 
the final landform and surface rehabilitation; 

•  a design of the EWF that takes into consideration possible premature closure; 

• 

long-term stability analysis; 

•  a  proposal  for  the  control  and  monitoring  procedures  to  be  carried  out  during 

the after-closure phase. 

The general structure of a closure plan can be summarised as follows: 

1 Scope and Purpose  

1.1 Purpose  

1.2 Scope  

1.3 Phases of mine closure  

1.4 Review 

2 Project Summary 

2.1 Location 

2.2 Land ownership  

2.3 Mining tenure  

2.4 Postal address, site address and contact details  

2.5 Project history  

2.6 Overview of operations  

2.7 Closure domains  

3 Closure Obligations and Commitments  

3.1 European Legal Obligations Register  

3.1 National Legal Obligations Register 

4 Stakeholder Engagement  

4.1 Stakeholder identification  

4.2 Stakeholder engagement register 

5 Post–Mining Land Use and Closure Objectives  

5.1 Pre-mining land use  

5.2 Post–mining land use  

5.3 Closure objectives and guiding principles  

6 Completion Criteria  

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6.1 Basis for development  

6.2 Development of completion criteria  

7 Collection and Analysis of Closure Data  

7.1 Climate Observations  

7.2 Flora and Vegetation  

7.3 Fauna  

7.4 Soils  

7.5 Hydrogeology  

7.6 Hydrology  

7.8 Geotechnical assessment  

7.8 Socio-economic Situation 

7.8 Cultural Heritage 

7.9 Characteristics of the resource  

7.10 Natural background data for water and soil  

8 Identification and Management of Closure Issues 

9 Rehabilitation Options and Evaluation in General 

9.1 General remarks and unit prices  

9.2 Rehabilitation options for mine openings  

9.3 Rehabilitation options for waste rock heaps 

9.4 Rehabilitation options for buildings and processing plant areas  

9.5 Rehabilitation options for tailings ponds  

9.6 Rehabilitation options for mine water  

9.7 Closure Costing 

9.8 Option analysis per object and conclusion of preferred option  

10 Closure Implementation  

10.1 Closure domains 

10.2 Timeline for closure  

10.3 Mine openings closure work program  

10.4 Waste rock heaps closure work program 

10.5 Tailings ponds closure work program 

10.6 Infrastructure area closure work program  

10.7 Infrastructure area closure work program 

10.8 Water and soil management  

10.9 Unexpected closure – care and maintenance 

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11 Closure Monitoring and Maintenance 

11.1 Geotechnical monitoring 

11.2 Soil monitoring  

11.3 Water monitoring  

11.4 Biodiversity monitoring  

12 Financial Provisioning for Closure  

13 Management of Information and Data  

14 References  

The closure plan should include a Gantt chart, or similar, to show the activities (tasks 
or events) over the planned timeframe. This provides greater clarity on the sequencing 
of works/tasks/events and the expected timeframes. The sections below provide details 
for some parts of the closure plan structure. 

3.4.3  Site Investigation and Extractive Waste Characterization  

In order to support the identification of potential environmental risks and impacts asso-
ciated with the extractive waste site and extractive waste management options, BAT is 
to use all of the following techniques (MWEI BREF): 

• 

• 

Identification of extractive waste site options 

Identification  of  extractive  waste  handling/  transport,  treatment  and  deposition 
options. 

In  analogy  to  the  provisions  given  in  Environmental  Protection  Agency  of  Ireland 
(2014), following topics need to be addressed in the frame of the site evaluation:  

Operator performance, to include information relating to: 

•  any existing Environmental Management System (EMS) for the activity; 

•  compliance, enforcement, incident and complaint history; and 

•  any  relevant  results  of  monitoring  and/or  site  investigations  carried  out,  which 
may  include  baseline  monitoring/conditions  that  existed  prior  to  the  com-
mencement of site operations (where available). 

Environmental pathways and sensitivity, to include: 

•  details on the underlying geology/hydrogeology; 

•  proximity to surface water bodies, their classification and status; 

•  proximity to sensitive receptors, including humans; 

•  details on the nearest natural habitat, Natura2000 and national habitats; 

• 

list  of  all  emission  and  discharge  points,  including  the  quantities  of  materials 
(solid/liquid/gas) emitted; and 

•  neighbouring developments, etc. 

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The  environmental  sensitivity  should  also  consider  the  potential  pathways  through 
which  the  operation  may  impact  on  the  surrounding  environment.  It  should  be  noted 
that much of the preparatory information required for this section will be available from 
existing information (see above). 

Site processes and activities, to include: 

•  overview of the processes and activities undertaken at the site; 

•  detailed maps of the site and building layouts (to an appropriate scale); and 

• 

the  different  process  areas,  e.g.  incoming  raw  materials,  production  units,  dis-
patch area, waste handling/storage areas, water/waste water treatment areas. 

Inventory of buildings, plant and equipment, to include: 

• 

list of all buildings and major plant and equipment; 

•  details  of  any  hazardous  or  potentially  polluting  components  and  construction 

materials, e.g. PCBs, asbestos; 

• 

list of all bunded, secured and protected areas; and 

•  details of any tests on bunds, pressure tanks, pipelines, etc. 

Inventory of raw materials, products and wastes, to include: 

•  a  comprehensive  list  of  all  raw  materials,  products  and  waste,  including  non-

hazardous and hazardous materials; and 

• 

the quantities of each item identified in the inventory. 

Maximum storage capacity for raw materials, products and wastes and maximum stor-
age amount in practice. 

Important  is  the  assessment  of  the  baseline  situation,  as  well  as  the  environmental 
using the source  – pathway – receptor model. In case that polluted material is identi-
fied,  the  hot  spots  of  pollution  must  be  subject  to  rehabilitation  planning.  The  goal  of 
risk-based rehabilitation is to reduce present and future risk in a cost-effective manner 
through the use of one or more of the following risk reduction techniques: 

•  Chemical source reduction —  Achieved by physical removal or control of haz-

ardous substances. 

•  Receptor  restriction  —  Land  use  controls  and  physical  barriers  (e.g.,  concrete 
caps and site fencing) that prevent the exposure of hazardous substances until 
source concentrations are reduced below risk levels. 

•  Chemical  pathway  elimination  —  Examples  include  placing  restrictions  on  ex-
cavation or groundwater use to prevent on-site or off-site receptors from making 
contact  with  chemicals  of  concern.  Identified polluted hot spots will be consid-
ered in the option analysis. 

3.4.4  Option Analysis  

Scope of the assessment of closure options is to find the best system which meets the 
requirements  in  terms  of  the  regulatory  requirements  and  complies  with  the  specific 
closure objectives for the respective mining site. The purpose of the option analysis is 
the optimisation process to find the ‘best’ alternative. In general, after the exploitation 

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of  the  mines  they  will  be  closed  because  of  economic  reasons  and  to  ensure  public 
health and safety to reduce negative environmental impacts. The methodology adopted 
comprises, for each option analysis, the following steps: 

1.  Specify design parameters: targets to be met, relevant unit costs, other relevant 

parameters 

2.  Define and describe suitable options. This activity includes: 

•  summarise base data and general options that are state of the art 

•  update strategic options based on new information available 

•  cost estimation 

In  theory  there  are  often  many  options,  but  common  sense  is  necessary  to  screen 
down the list to a small number of practical robust alternatives which meet the objec-
tives  and  are  not  clearly  ruled  out  on  grounds  of  practicality,  legality  and  consistency 
with local circumstances. Further the very specific objectives which have to be met by 
the system circumscribe the number of options available. 

3.  Define evaluation criteria to identify the best option. Important criteria are: 

•  Cost (investment, O&M costs) 

•  Environmental aspects (not only the negative impacts from construction and 
operation, but also the positive impacts resulting from the environmental im-
provement); 

•  Technical  aspects  (efficiency  (in  achieving  targets),  robustness,  technical 

maturity) 

•  Legal  aspects  (complies  with  legislation,  whether  compatible  with  existing 

institutional structures); 

• 

Implementation risks (public acceptance, threatens existing vested interests, 
time needed to implement) 

4.  Identify best option. 

5.  Draw conclusion based on the foregoing. 

The methodology for the identification of the best option consists of two parts: a tech-
nical  analysis  and  a  financial  analysis.  Within  the  technical  analysis  is  analysed  the 
technical feasibility and the applicability of several options and their resulting environ-
mental impacts. In parallel are analysed the cost, taking into account investment cost 
and  operation  and  maintenance  cost.  In  general,  a  solution  must  be  applicable  from 
technical  point  of  view  first,  and  in  the  next  step  is  analysed  the  cost.  The  approach 
depends in each case on the options being compared, and is discussed further when 
options are being evaluated. The direct cost analysis must consider investment cost as 
well as operation and maintenance (O&M) cost, and both are used to prepare prelimi-
nary estimates for the cost comparison of the closure options. The investment cost and 
the  O&M  cost  are  to  be  calculated  and  assessed  separately,  and  finally  will  be  con-
cluded the result in terms of the preferred option regarding cost. The Net Present Value 
(NPV),  a  profitability  indicator,  expressed  as  sum  of  the  present  values  of  all  project 
cash flows over the first n years, will be calculated in a Financial Analysis for the total 
system that consists of components which are the result of the preferred option. 

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3.4.5  Closure Tasks  

Closure tasks per objects and per mining typology can be identified from section C of 
this guidance. In the report shall be detailed the tasks necessary to achieve successful 
closure  and  provide  a  program  (Gantt  chart  or  similar)  for  the  entire  closure  process 
with all key activities included (Environmental Protection Agency of Ireland, 2014). De-
tails should include (Environmental Protection Agency of Ireland, 2014): 

•  plant and equipment decontamination; 

•  plant and equipment decommissioning; 

•  demolition (if necessary); 

•  waste facility closure (e.g. landfill and extractive waste facilities); 

• 

raw materials, products and waste disposal and/or recovery; 

•  contaminated land treatment, removal and/or disposal; and 

•  programme (Gantt chart or similar) and timeframes for delivery. 

Proposals  regarding  contaminated  land  treatment,  removal  and/or  disposal  should  in-
clude the following details (Environmental Protection Agency of Ireland, 2014): 

•  baseline/existing conditions; 

•  proposed  rehabilitation  methods  and  their  current  status,  including  details  of 

any agreements reached with the competent authority; and 

•  monitoring proposals. 

For each element the report must contain a detailed rehabilitation work schedule (pro-
gressive and after shutdown of mining activities) including the human and material re-
sources involved (Gouvernement du Québec, 1997). 

3.4.6  Closure Plan Costing  

The elaboration of a closure plan is typically based on the costing stage of conceptual 
design  for  the  remedial  option  analysis,  and  detailed  design  for  the  preferred  option. 
Beside the design cost, and according to the International Council on Mining and Met-
als ICMM (2019), several types of cost estimates are used to characterise the financial 
aspects of closure, that are illustrated in figure 15. 

Figure 15: Closure cost estimate types, Legend: LoA - Life of asset (ICMM, 2019) 

Closure cost estimates frequently need to be estimated for the implementation of clo-
sure activities many years or even decades in the future. In this context, it is important 
to be realistic about the achievable accuracy of cost estimates (ICMM, 2019). 

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3.4.7  Criteria for Successful Closure  

In  analogy  to  the  Environmental  Protection  Agency  of  Ireland  (2014) following criteria 
have  been  established  to  set  the  benchmark  for  the  successful  closure  of  the  site 
(amended): 

•  plant safely decontaminated using standard procedures and authorised contrac-

tors; 

•  wastes handled, packaged, stored and disposed or recovered in a manner that 

complies with regulatory requirements; 

• 

relevant records relating to waste and materials management retained through-
out the closure process; 

•  no soil or groundwater contamination at the site, verified using monitoring data; 

•  and a soil and groundwater assessment at the time of closure (if required); 

•  hazard and/or risk of environmental pollution is returned to a satisfactory state; 

• 

long term geotechnical stability is ensured, verified using monitoring data; 

•  sufficient funds available to cover the full cost of closure; and 

•  Environmental  management  system  in  place  and  actively  implemented  during 

closure. 

Due  to  International  Council  on  Mining  and  Metals  ICMM  (2019),  the  SMART  ap-
proach (specific, measurable, achievable, relevant, timely) is useful for developing and 
accessing success criteria. Key considerations for each element of SMART criteria are 
as follows (ICMM, 2019): 

Specific: Criteria should relate directly to closure objectives and individual closure ac-
tivities.  A  closure  activity  or  group  of  closure  activities  without  an  associated  criterion 
indicates a gap; a criterion without an associated measure  or measures may indicate 
the criterion is too general. 

Measurable: If a criterion cannot be measured, there is no way to stakeholders that it 
has been met. While the method of measurement is usually obvious for numerical crite-
ria,  narrative  criteria  may  require  alternative  forms  of  measurement  (such  as  comple-
tion of a given task as confirmed through as-built drawings or field inspections). Some 
objectives may require a combination of qualitative and quantitative measurement. 

Achievable: If relinquishment or return of financial assurance is to be attained, realistic 
criteria are crucial are to be achieved. Unrealistic or poorly defined criteria can delay or 
prevent relinquishment, or unnecessarily extend monitoring periods. 

Relevant: Criteria should ultimately be aligned with closure objectives and the social, 
environmental and regulatory context of the site. 

Timely: Criteria will have a time component, either explicitly or implicitly. Some can be 
considered  completed  immediately  after implementation of the associated closure ac-
tivities while others will require a period of monitoring. 

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3.4.8  Accompanying Documents 

In case of water-related structures, it might be required a water management plan in-
cluding water balance and design flood analysis (Garbarino et al. 2018). 

3.4.9  Closure Plan Validation and Audit 

This  section  should  detail  the  environmental  monitoring  and  validation  provisions  that 
will  be  in  place,  the  scope  and  criteria  for  the  validation  audit,  the  qualifications  and 
independence  of  the  auditor  and  the  nature  of  the  report  and  closure  certification  re-
sulting from the audit (Environmental Protection Agency of Ireland, 2014). 

3.4.10  Environmental Impact Assessment  

Environmental  assessment  as  such  is  a  process  that  ensures  that  environmental  ef-
fects of projects are assessed and taken into account before the decisions of their au-
thorisations are taken. Figure 16 gives a general overview on the existing environmen-
tal  assessment  approaches  with  respect  to  mining.  Legend:  SEA  –  Strategic  Impact 
Assessment,  EIA  –  Environmental  Impact  Assessment,  EMS  –  Environmental,  Man-
agement System, LCA – Life Cycle Assessment. 

Figure 16: Overview on the existing environmental assessment approaches with re-
spect to mining 

Strategic  Impact  Assessment  (SEA)  is  a  legal  instrument  for  the  environmental  im-
pact assessment of plans and programs. With SEA, potential environmental impacts of 
a  planning  can  be  recognized  and  taken  into  account  before  the  plan  or  program  is 
accepted. Typical applications are regional development plans, land use plans, waste 
management plans, energy concepts, etc. In the European Union, SEA is based on the 
EC  Directive  (2001/42/EC)  on  the  assessment  of  the  environmental  effects  of  certain 
plans and programs. 

In the mining sector, SEA plays a major role in regional planning, as reserve areas and 
priority areas for mining are identified as a result of the localization of ores and mineral 
resources. In this regard, SEA precedes the Environmental Impact Assessment (EIA). 
While the EIA is used for the approval of environmentally relevant projects, SEA is al-
ready carried out at the planning stage. 

Environmental impact assessment (EIA) is a process governed by law. It serves to 
determine,  describe  and  evaluate  in  advance  the  impacts  of  projects  on  the  environ-
ment,  including  human  health.  Generally,  mining  operations  are  subject  to  EIA,  de-
pending  on  their  type.  EIAs  according  to  Directive  2011/92/EU  as  amended  by 

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2014/52/EU are carried out to assess of individual projects in a formalized, systematic 
and  comprehensive  process  of  identifying  and  evaluating  the  environmental  effects. 
Impact  Assessment  has  to  be  done  ex-ante  with  participation  of  public  and  relies  on 
multidisciplinary input. Figure 17 shows the flow chart illustrating the EIA process. 

Figure 17: Flow chart illustrating the EIA process (Source: European Commission 
Scoping Guidance, 2017) 

The environmental impact assessment analyses, evaluates and identifies: 

1) Direct and indirect impact of a given project on (EIA Directive, Art.3(1)): 

a.  the environment and the population, including the health and living con-

ditions of people 

b.  material goods 

c.  monuments 

d.  landscape, including cultural landscape 

e.  interactions between abovementioned elements 

f.  availability of mineral deposits 

g.  risk of serious accidents and natural and construction disasters 

2) Means and ways to avoid, prevent, reduce and if possible offset the significant ad-
verse effects of project on the environment; 

3) Required parameters and duration of monitoring. 

Furthermore, the EIA process needs to include an appropriate assessment required for 
N2000 sites under Art. 6 of the Council Directive 92/43/EEC (Habitats Directive), as its 
scope and binding conclusion concerning permitting differ from the SEA and EIA provi-
sions. The link with those directives is detailed in the guidance “Managing and protect-
ing Natura 2000 sites” at  

https://ec.europa.eu/environment/nature/natura2000/management/guidance_en.htm 

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Environmental  Management  Systems  (EMS)  are  part  of  the  overall  overarching 
management system, which includes the organizational structure, responsibilities, for-
mal  procedures,  and  means  for  the  implementation  of  the  environmental  policy  of  a 
company.  ISO  14001:2015  specifies  the  conditions  for  an  EMS  that  an  organization 
can use to enhance its environmental performance (Schneider et al. 2017). 

Life  Cycle  Assessment  (LCA)  is  a  systematic  analysis  of  environmental  effects  of 
products  throughout  the  life  cycle.  The  preparation  procedure  is  laid  down  in  ISO 
14040:2006.  LCA  includes  all  environmental  effects  during  the  production,  the  utiliza-
tion  phase  and  the  disposal  of  the  product,  as  well  as  the  associated  upstream  and 
downstream  processes  (e.g.  production  of  the  raw  materials  and  supplies).  Environ-
mental impacts are classified in impact categories and include all environmentally rele-
vant  withdrawals  from  the  environment  (e.g.  ores,  petroleum)  and  emissions  into  the 
environment  (e.g.  waste,  CO2  emissions).  The  overall  scope  of  the  assessment  is  to 
identify environmental optimization potential in order to achieve a cradle-to-cradle sys-
tem (Braungart & McDonough, 2002). 

Figure 18 illustrates influence and impact by mining phase, and analysis potential im-
pact  measures  that  can  be  taken  to  offset  impact  according  to  Hofsteenge  et.  al. 
(2017). 

Figure 18: Influence and impact by mining phase. Analysis of potential impact 
measures that can be taken to offset impact (Hofsteenge et. al, 2017) 

The EIA methodology is based on the following criteria: 

•  Spatial extent of the impact 

•  Temporal extent of the impact 

•  Severity of the impact 

At least the following criteria will have to be taken into account for the assessment: 

•  Existing degradation or disturbance of areas or nature 

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•  Proximity of sensitive habitats or specially protected areas, presence of protect-

ed species 

•  Sensitivity of receptors to a given impact 

•  Area in which disturbances (noise, dust) may be noticed and may have signifi-

cant nuisance levels 

• 

Impact on water or air so that legal quality standards are exceeded  

•  Potential of water contamination in case of accidental spills 

The severity of impacts is ranked according to the following qualitative scheme that is 
based on the sensitivity of receptors and magnitude of impacts. It should be noted that 
the application of the criteria always contains a subjective element. Therefore, the fol-
lowing tables should be used as orientation and need to be applied with a site-specific 
focus. 

Sensitivity 
Low 

Medium 

High 

Table 4: Definitions of sensitivity levels of receptors 

Description 

Areas have already been significantly degraded 
Non-designated or locally designated sites/habitats 
Non-sensitive receptor with regards to the impact type (e.g. noise 
receptors) 
Partially degraded area 
Regionally designated sites / habitats 
Regionally rare or endangered species 
Moderately sensitive receptor with regard to the impact type 
Nationally or internationally designated sites/habitats 
Species protected under national or international laws / conventions 
High sensitivity with regard to the impact type 

The  significance  of  the  impact  is  calculated  by  multiplying  the  assigned  values  for 
magnitude  of  the  potential  impact  and  the  sensitivity  of  the  receptor  to  generate  an 
evaluation matrix. 

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Table 5: Definitions of magnitude levels of impacts 

Magnitude  Description 
Minor 

Moderate 

Major 

Reversible 
Duration < 2 years 
Will not cause any material change to the value or function of the 
receptor 
Emissions comply with regulations 
Emissions contained within project footprint 
Local disturbance 
Potentially irreversible 
Duration > 2 and < 10 years 
Causes a change in the value or function of receptor but does not 
fundamentally affect its overall viability 
Emissions comply with regulations 
Emissions reach outside Project footprint 
Local/Regional disturbance 
Mainly irreversible 
Duration > 10 years 
Causes a significant change in the environment affecting the viability, 
value and function of the receptors 
Unmitigated emissions or other impacts do not comply with regulations 
and need to be reduced 
Emissions reach outside Project footprint and may extend to national or 
transboundary influence 

The  significance  of  the  impact  can  be  summarised  in  terms  of  numerical  values  as 
shown in the significance table below, verbally or through a colour key. Higher impact 
significance  reflects  a  higher  severity  of  impact  and  requires  customized  mitigation 
measures. The EIA procedure considers risks during the rehabilitation works, and the 
remaining risks after the rehabilitation works. 

Table 6: Numerical ranking and verbal category of impact significance 

Numerical impacty ranking (impact 
magnitude x receptor sensitivity) 

Verbal category of 
impact significance 

0-1 

2 

3-4 

6 

9 

+ 

Negligible 

Minor 

Moderate 

Major 

Critical 

Denotes overall positive 

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3.4.11  Environmental Management Plan  

An Environmental Management Plan (EMP) can be defined as an environmental man-
agement  tool  used  to  ensure  that  undue  or  reasonably  avoidable  adverse  impacts  of 
the construction, operation and decommissioning of a project are prevented; and that 
the positive benefits of the projects are enhanced. An EMP is based on the principles 
of Environmental Management Systems (EMS) according to ISO 14001:2015. An EMP 
is not foreseen in the EWD, however it represents Best Practice in construction works 
(like an Occupational Health and Safety Plan). Both types of plans might be required by 
the competent authority. An EMS basically includes 1) the environmental policy, 2) ob-
jectives and programs, 3) organization and personnel, 4) impact on the environment, 5) 
design  and  process  control,  6)  environmental  management  documentation,  7)  envi-
ronmental  audits  (Schneider  et  al.  2017).  On  international  scale  the  most  common 
standardized EMS is provided by ISO 14001:2015. In the European Union further ex-
ists  the  “EU  Eco-Management  and  Audit  Scheme”  (EMAS),  a  premium  management 
instrument developed by the European Commission for companies and other organiza-
tions to evaluate, report, and improve their environmental performance. 

3.4.12  Occupational Health and Safety Plan  

A health and safety program is a definite plan of action designed to prevent accidents 
and  occupational  diseases,  and  it  is  based  on  a  hazard  assessment  for  all  activities 
with risks to health and safety in line with the principles of ISO 45001:2018. It contains 
provisions for safe working procedures as well as emergency procedures. 

3.5  Design of an After-closure Plan 

3.5.1  Approach to After-closure 

After-closure  refers to longer term measures that are necessary where environmental 
liabilities  remain  following  closure,  e.g.  contaminated  soil  and  groundwater,  landfills, 
extractive  waste  facilities,  mines,  quarries  and  soil  recovery  facilities.  Measures  may 
encompass activities such as rehabilitation, ongoing emissions control and monitoring 
(Environmental  Protection  Agency  of  Ireland,  2014).  The  two  main  circumstances  re-
quiring an after-closure plan are: 

•  soil and groundwater contamination; and 

• 

landform changes, e.g. landfills, extractive waste facilities, mines, quarries and 
soil recovery facilities 

The projection of after-closure monitoring works and the financial assessment of after-
closure monitoring costs. The following issues are to be addressed: 

1. The monitoring objectives;  

2. Data required  

2.1 Monitoring the surface stability  

2.2 Water monitoring  

2.3 Air monitoring  

2.4 Monitoring the tailing ponds and the stability of decant ponds structure  

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2.5 Monitoring the ecosystems and vegetation 

3. Quality management  

4. Data Management  

5. Estimation of costs required for fulfilling the long-term tasks.  

6. Models of monitoring and impact mitigation plans.  

3.5.2  After-closure Measures and Activities 

Examples  of  after-closure  measures  include  (Environmental  Protection Agency of Ire-
land, 2014, amended): 

•  maintenance of surface water drainage systems; 

•  maintenance of green and plantations; 

•  operation of contaminated soil and groundwater pump and treat systems; 

•  monitoring (e.g. water, air, gas, leachate, stability, biodiversity); 

•  maintenance of access to monitoring locations; 

•  servicing and calibration of monitoring equipment (e.g. continuous water quality 

monitors); 

•  Landscape maintenance of grass cover and planting; 

•  staff resourcing; and 

•  site security (e.g. inspections/patrols, fencing) 

3.5.3  Restoration and After-closure Costing 

Both the rehabilitation and after-closure proposals require detailed costing by operators 
(Environmental Protection Agency of Ireland, 2014). 

For sites where significant soil and groundwater contamination is present, the following 
items should be costed (Environmental Protection Agency of Ireland, 2014): 

• 

site investigation works (e.g. drilling and groundwater well installation) in order 
to delineate the extent and magnitude of contamination; 

•  environmental  risk  assessment  in  order  to  determine  whether  risk  is  posed  to 
environmental receptors and to devise an appropriate rehabilitation strategy; 

• 

implementation  of  a  rehabilitation  programme  such  as  excavation,  treatment, 
environmental verification testing and/or design and installation of in-situ treat-
ment systems; 

•  maintenance  and  monitoring  costs  associated  with  the  site  rehabilitation,  e.g. 
costs  of  maintenance  of  the  treatment  plant  associated  with  a  pump  and treat 
system  or  the  costs  of  groundwater  monitoring  associated  with  a  monitored 
natural attenuation (MNA) programme; 

•  staff resourcing; and 

•  site security (e.g. inspections/patrols, fencing). 

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For landform changes, the following items should be costed (Environmental Protection 
Agency of Ireland, 2014): 

• 

restoration  measures,  e.g.  reclamation  of  excavated  areas,  seeding  and  land-
scaping 

•  maintenance of surface water drainage systems 

•  ongoing  pollution  control  measures,  e.g.  landfill  gas  extraction  and  flar-

ing/utilisation, landfill leachate extraction and treatment/disposal 

•  maintenance of access to monitoring locations 

•  monitoring (e.g. surface water, groundwater, air, gas, leachate, stability) 

•  servicing and calibration of monitoring equipment (e.g. continuous water quality 

monitors) 

• 

landscape maintenance 

•  staff resourcing; and 

•  site security (e.g. inspections/patrols, fencing). 

A proposal for review of the closure plan should be provided. Typically, restoration and 
after-closure plans must be reviewed annually and proposed amendments thereto noti-
fied  to  the  competent  authority  for  agreement  (Environmental  Protection  Agency  of 
Ireland,  2014).  Also  restoration  and  after-closure  costing  must  be  reviewed  annually, 
and updated respectively. 

3.5.4  Environmental Monitoring Plan 

Environmental Monitoring (EM) refers to the observation of scientifically relevant areas 
of  the  environment  and  the  documentation  of  ecological  parameters  (Schneider  et  al. 
2017).  The  scientific fields include biology, soil science, chemistry, geography, geolo-
gy,  hydrology,  meteorology  and  physics.  The  findings  can  be  important  for  forestry, 
landscape  planning  and  other  environmentally  relevant  planning  tasks  and  problems, 
as well as the scientific monitoring of environmental projects. The goal is the long-term 
recording  of  environmental  and  environmental  protection-relevant  changes  in  air,  soil 
and water. Impacts on landscape and biodiversity can thus be systematically recorded. 

In terms of the implementation of CP strategies in the mining sector, EM plays a role in 
all design and operational steps. An EM plan needs to be provided by the applicant for 
the respective EIA project, and will be complemented by an obligatory EM plan through 
the mine approval by the competent authority (Schneider et al. 2017). 

3.5.5  Rehabilitation and After-closure Plan Review 

A  proposal  for  review  of  the  closure  plan  should  be  provided.  Typically,  after-closure 
plans  must  be  reviewed  annually  and  proposed  amendments  thereto  notified  to  the 
competent authority for agreement (Environmental Protection Agency of Ireland, 2014). 

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4.  Part C: Overview on Closure Best Practices by Mining Typology 

4.1  Best Practices Overview 

Best  Practice  is  a  technique  or  methodology  that,  through  experience  and  research, 
has been proven to reliably lead to a desired result. Best practices are used to maintain 
quality as an alternative to mandatory legislated standards and can be based on self-
assessment or benchmarking. The further step of Best Practice is the application of the 
Best Available Techniques (BAT), the most effective and advanced stage in the devel-
opment of an activity and its methods of operation. In Europe, the Best Available Tech-
niques  (BAT)  reference  documents,  the  so-called  BREFs,  are  the  explanation  docu-
ments that have been adopted under both the Directive on Integrated Pollution Preven-
tion  Control  IPPC  (2008/1/EC)  and  the  IED  Industrial  Emissions  Directive  (IED, 
2010/75/EU).  BAT  refers  to  operating  facilities.  Good  Operating  Practice  (GOP)  is  a 
strategic  management  term.  The  term  best  environmental  practice  (BEP)  means  the 
application of the most appropriate combination of environmental control measures and 
strategies. Best available techniques not entailing excessive costs (BATNEEC), some-
times  referred  to  as  best  available  technology  was  introduced  in  1984  into  European 
law  with  Directive  84/360/EEC.  The  BAT  concept  was  first  time  used  in  the  1992 
OSPAR Convention for the protection of the marine environment of the North-East At-
lantic for all types of industrial installations. 

4.2  BREF for Extractive Waste Management  

The  Best  Available  Techniques  Reference  Document  for  the  Management  of  Waste 
from Extractive Industries (MWEI BREF, Garbarino et al. 2018) is a technical document 
representing the results of the latest exchange of information, organised by the Com-
mission, on Best Available Techniques (BAT) for the management of extractive waste 
and  associated  monitoring,  based  on  the  developments  in  the  extractive  waste  man-
agement  sector  since  the  elaboration  of  the  initial  Best  Available  Techniques  Refer-
ence  Document  for  the  Management  of  Tailings  and  Waste-Rock  in  Mining  Activities 
(MTWR BREF). The MWEI BREF refers exclusively to mine waste management, and 
not to the closure of other extractive facilities like shafts and opencast mines. 

Processes and activities covered by the MWEI BREF BAT Conclusions:  

• 

• 

• 

• 

• 

the management of extractive waste from onshore extractive activities 

the  handling/transport  of  extractive  waste  (e.g.  loading,  unloading  and  on-site 
transport) 

the treatment of extractive waste 

the deposition of extractive waste 

the activities directly associated with the management of extractive waste. 

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According to the Terms of Reference of this study, the documentation refers to MWEI 
BREF for extractive waste management; however, it goes beyond MWEI BREF for fur-
ther closure techniques like for instance shaft closure. 

To apply a design for closure and after-closure approach by including an initial closure 
and after-closure planning of the extractive waste deposition area (including the EWF) 
that may contain the following (MWEI BREF): 

•  a preliminary identification of the covering techniques (MWEI BREF BAT 38); 

•  a  preliminary  identification  of  the  techniques  to  prevent  and  control  water  and 

wind erosion (MWEI BREF BAT 21 and BAT 49); 

•  an assessment of costs related to the proposed and alternative closure strate-

gies including a cost benefit analysis; 

•  an Environmental Risk and Impact Evaluation (MWEI BREF BAT 5); 

•  a specific indication of the closure process to be followed, specifying if the re-
habilitation will be progressively carried out during the operation phase or when 
progressive rehabilitation is not possible, it will be entirely carried out in the clo-
sure phase; in the latter case, the initial closure and after-closure planning ex-
plicitly states if a dry or wet cover will be implemented and provides details on 
the final landform and surface rehabilitation; 

•  a design of the EWF that takes into consideration possible premature closure; 

• 

long-term stability analysis (MWEI BREF BAT 22); 

•  a  proposal  for  the  control  and  monitoring  procedures  to  be  carried  out  during 

the after-closure phase (MWEI BREF BAT 3, 23, 40, 48 and 52). 

If  possible,  the  closure  and  after-closure  planning  of  the  extractive  waste  deposition 
area is integrated into the periodic extraction plans. 

4.3  Mining Typology 

In general, the term “mining” refers to exploration, extraction and processing of mineral 
resources  from  the  earth's  upper  crust  using  technical  facilities  and  recourses.  The 
extraction comprises of the exploitation of raw materials of mineral and fossil origin as 
well as the generation of geothermal heating.  Additionally, the underground mining is 
becoming  increasingly  important.  All  mining  activities  are  regulated  worldwide  by  the 
respective  mining  law  within  the  national  legislation.  All  mining  operations  require  an 
operation plan, which also regulates the closure and reclamation after the completion 
of mining works. Depending on the raw material and specific deposit conditions differ-
ent extraction methods are used. The mining exploitation and processing shall be con-
sidered as a mining complex. The extraction of deposits is distinguished between:  

•  Underground mining  

•  Opencast mining 

•  Borehole mining. 

Different underground and opencast extraction methods can be  used. The mined raw 
materials can be divided into three major groups:  

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Element resources (aiming on a certain element): These are aggregates, ores, as well 
as precious and semi-precious stones, but might include also industrial minerals. 

Energy resources: hydrocarbons, coal and uranium. 

Property resources (aiming on a certain material characteristics): These include raw 
materials  for  metallurgical  and  chemical  processes,  as  well  as  salt  and  fertilizer  raw 
materials.  

In terms of technological characteristics, the resources are usually divided in a) aggre-
gates, b) Industrial Minerals, c) ores, and d) energy minerals. The specific characteris-
tics  of  the  groups  are  considered  in  more  detail  below,  with  a  raw  material-specific 
group derived from the groups above mentioned. 

It should be noted that the site specific conditions as type of raw material (unconsoli-
dated  rock,  hard  rock,  hydro-soluble,  sulfidic,  type  of  surrounding  rock  etc.)  and  the 
type  of  extraction  (open-pit  as  drift  mining  or  slope  mining, hard rock, unconsolidated 
rock,  underground  mining,  borehole  mining,  solution  mining,  etc.)  are  very  diverging. 
Each closure plan is site specific and not transferable to another site. The GD provides 
a  general  overview  to give guidance on the general steps and conditions to be taken 
into consideration for the respective mine closure. 

4.3.1  Aggregates 

The  term  “aggregate”  refers  to  coarse  particulate  material  such  as  crushed  stone, 
gravel, sand, clay, and marl. Aggregate is used in the construction of buildings, roads, 
dams,  and  other  infrastructure  as  a  base  material  or  in  composite  material  such  as 
concrete.  In  terms  of  material  rheology,  the  original  material  for  the  production  of  ag-
gregates are divided into coarse rock materials (soil and sandy or clayey materials) and 
solid  rock  materials  (used  for  crushed  rock  and  dimension  stones).  Aggregates  (also 
known as inorganic non-ores), as a component from the group of element raw materi-
als, combine various non-metallic, mineral-abiogenic and mineral-biogenic raw materi-
als. Basically, there are: 

Mass commodities: coarse rock (sand, gravel), crushed sand (e.g. basalt) 

Binder: Cement, carbonate / limestone, gypsum / anhydrite stone, clay / kaolin, quartz 
sands 

Dimension stones 

Industrial minerals for special applications (see point. 4.3.4) 

The  mining  of  raw  materials  takes  place  predominantly  by  the  opencast  method. 
Whereby  a  relatively  high  output  (over  60…  90%)  is  technologically  based  on  a  high 
level of extraction, both in terms of mining and processing technology. Overburden or 
rock of lower qualities is usually used for the reclamation of excavated areas. After the 
relevant drilling exploration works, the mining exposure of the deposit is generally car-
ried out in a combination of ramps (exploratory works), berms (pre-processing works) 
and  benches  (extraction).  Following  illustrations  show  a  typical  exploratory  and  pre-
processing works as well as extraction activities in an aggregate mine. 

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 Figure 19: Basic illustration of a sand and gravel opencast mine 

-  Exploratory works 
-  Pre-processing works (berms) 
-  Extraction (benches) 

The  reclamation  of  excavated  areas  of  opencast  mines  will  be  done  in  parallel  to  the 
ongoing extraction works. This mining method results the relatively high output. Figure 
20 shows example of manufactured sand processing from hard rock.  

Figure 20: View of an aggregates mine (left); aggregates processing plant (right) 

According to the respective legislation, the topsoil that occurs during the mining opera-
tions has to be used for later reclamation or to be sold as raw material (e.g. as a basis 
for the greening of mining waste heaps or tailing ponds).  

Further extraction and mining possibilities are the dredging within the groundwater lev-
els or from rivers or lakes (figure 21). Large gravel and sand deposits support signifi-
cantly groundwater resources. With the extraction of gravel and sand, the nature and 
especially the water balance will be significantly changed. The changes to groundwater 
system cannot be restored, especially in wet mining. Therefore, frequently it comes to 
the conflict of interests between extraction of gravel and sand and the protection of the 
groundwater. 

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Figure 21: Example of a sand dredging facility 

The available BAT document for the aggregates sector is “Best Available Techniques 
(BAT)  Reference  Document  for  the  Production  of  Cement,  Lime  and  Magnesium  Ox-
ide: Industrial Emissions Directive 2010/75/EU. 

4.3.2  Ores 

Ores are naturally occurring mineral aggregates of economic interest, from which one 
or more components of value can be extracted by processing. Most of these are min-
erals that contain more or less metallic components. From a mining point of view, the 
distinction based on criteria is the most effective, i.e. ores are distinguished from metal 
cations. 

•  Black metal ores: Fe, Mn, Cr, Ti, Ni, Co, W, Mo, V 

•  Non-ferrous metal ores: Cu, Pb, Zn, Sn 

•  Light metal ores: Al, Mg, Li, Be 

•  Precious metal ores: Au, Ag, Pt 

The  available  BAT  document  for  the  ore  mining  sector  is  “Best  Available  Techniques 
(BAT) Reference Document for the Non-Ferrous Metal Industry”. 

Ore mining takes place in open-cast or underground mining. In-situ leaching (ISL) is a 
special  feature,  which  can  be  applied  for  ore  extraction  from  the  rock  in  both,  under-
ground  and  above  ground.  The geological, geotechnical and environmentally relevant 
framework conditions are decisive for the choice of the mining method. Large, surface 
near mass deposits are usually exploited as open-cast mines, whereby the limit depth 
(separation  of  open-cast  mining  to  underground  mining)  can  be  defined  as  approxi-
mately  300  m.  For  the  mining  extraction,  the  connection  between  mining,  processing 
and smelting must be considered. Figure 22 shows the relations. 

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Figure 22: Relation between technologies and requirements for effective deposit utiliza-
tion 

Knowledge  of  the  underground  mining  methods  that  may  be  used  are  crucial  for  the 
subsequent remedial measures. A distinction is made in 

•  mining  process  with  scheduled  reclamation  of  excavated  areas  (full  or  partial 

reclamation) 

• 

• 

fracture  construction  method  with  lowering  of  the  slope  layers  (longwall  con-
struction) 

ridge  construction  or  ridge  joint  construction  method  with  placing  back  into  re-
maining open excavation space. 

Figure 23: Copper open cast mine in Andalusia, Spain 

In  addition  to  costly  expenses  for  subsequent  refilling  to  secure  the  surface,  the  ex-
pected  geotechnical  framework  conditions,  including  long-term  metrological  surface 
monitoring,  are  decisive.  For  this  purpose,  large  above-ground  piles  of  unproductive 
bedrock  were  and  are  still  being  built,  which,  despite  the  increased  return  of  such 
waste as material to the open underground mine, necessitates long-term above-ground 

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remedial measures. Figure 24 shows a sample of an overall planning model for under-
ground mining. 

Figure 24: Sample of an overall planning model for underground mining 

In  terms  of  underground  leaching  mining  (opening  of  chambers  with  interim  storage 
and  subsequent  leaching)  particularly,  long-term  effects  on  the  entire  extraction  pro-
cess, in part the uncalculated time sequences, must be taken into account. 

4.3.3  Energy Minerals 

A group of energy resources includes hydrocarbons, coal and uranium. 

•  Hydrocarbons:  petroleum  and  natural  gas  (associated  with  natural  asphalt, 

earth wax, bitumen and oil shale) 

•  Coal: lignite, hard coal and anthracite, peat, sapropel coal (caustobiolites) 

•  Uranium: raw material for nuclear power generation 

The available BAT document for the energy resource mining sector are: 

•  2008 BAT Guidance Note for the Energy (LCP) Sector 

•  2008 BAT Guidance Note for the Oil & Gas Refining Sector 

•  1996 Draft BATNEEC Guidance Note - Extraction of Peat - 14/05/96 

Hydrocarbon Extraction 

The  oil  and  natural  gas  resources  are  extracted  exclusively  (with  a  few  exceptions) 
through surface drilling up to a depth of approx. 2,000-3,000 m. Due to inclined drilling 
for oil and natural gas extraction in the so-called offshore areas the inclined drilling can 
reach a borehole length of up to 11 km. With regard to the geology of the deposit and 
the viscosity of the oil and thus ultimately the effort required for oil extraction, conven-
tional  deposits  are  distinguished  from  unconventional  ones.  Figure  25  illustrates  the 
reservoir formations of oil and gas deposits (left), oil and gas production facilities (right) 
according to Devold (2013). 

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Figure 25: Reservoir formations of oil and gas deposits (left), oil and gas production 
facilities (right) (Devold, 2013) 

Conventional deposits are located in relatively highly porous and permeable reservoir 
rocks  and  contain  relatively  low  viscosity  oil.  Unconventional  deposits  are  located  in 
rather  low-pored  and  impermeable  rocks  or  contain  more  viscous,  bituminous  oil,  so 
that the extraction can be only done through increased technical and energy expendi-
ture. The oil exploration takes place in phases:  

-  Prospection 

-  Development of oil deposits 

-  Extraction  

•  Primary extraction (the pressure within the deposit drives the oil to the sur-

face) 

•  Secondary  extraction  (If  the  pressure  in  the  deposit  drops  in  the  course  of 
oil  extraction,  it  can  be  increased  by  (re)injecting  water  or  natural  gas  into 
the deposit)  

•  Tertiary extraction (extraction of additional oil from the deposit through spe-

cial measures such as hot steam, CO2 or N2 and others) 

•  Offshore extraction 

Oil  sands  and  oil  shale  close  to  the  surface  are  also  mined  and  extracted  directly  in 
open-cast mines. Deep drilling has been made on a larger scale since the mid of 19th 
century.  The  state  of  the  art  in  producing,  operating  and  filling  of  boreholes  and  the 
applicable legal provisions have developed continuously since then and have reached 
a high standard based on long experience. 

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The extraction of natural gas resources is also differentiated from extraction from con-
ventional  deposits  (extraction  from  salt  domes,  and  from  non-conventional  deposits 
(hydraulic fracturing). Figure 26 shows a natural gas fracking example. 

Figure 26:  Example of natural gas extraction by fracking (source: U.S. EPA) 

Natural gas (methane) also occurs in coal seams or e.g. within potash seams. The ex-
traction  takes  place  onshore  and  offshore.  Figure  27  shows  a  scheme  of  oil  and  gas 
extraction.  

Figure 27:  Scheme of oil and gas extraction (source: MagentaGreen, CC BY-SA 4.0) 

Oil extraction causes significant damages to the environment. Even with conventional 
deposits, development and extraction cause adverse interventions in ecosystems, es-
pecially  offshore  plants.  In  addition,  flaring  of  associated  petroleum  gas,  which  is  still 
common  under  certain  circumstances,  also  damages  the  environment  through  emis-
sion of carcinogenic particulate, carbon dioxide, sulphur dioxide and nitrogen oxides. 

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Lignite Mining 

Coal  deposits  are  basically  divided  into  hard  coal  deposits  and  lignite  deposits.  Hard 
coal deposits are mostly mined underground (exceptions Canada, USA, Australia and 
Russia), lignite deposits are mainly open cast mined. Up to 90% of underground hard 
coal deposits are exploited upright and horizontal. Caving or room and pillar methods 
are used as extraction method. The mining depth is usually between 800 m and 1,000 
m below surface. In case of caving, load-bearing elements will be systematically thrown 
to breakage. The disadvantage of all types of caving methods is the significant subse-
quent damage of the surface, which can cause the subsidence of up to several meters. 
The  impact  on  the  environment  in  opencast  mining  is  mainly  determined  by  the  high 
land consumption. Further environmental impacts are the lowering of the groundwater 
level and dust formation. These are mainly large opencast mines for lignite extraction 
(figures 28 and 29). 

Figure 28: Open cast lignite mining in Eastern Germany 

Figure 29: Principle of open cast mining (Tudeshki & Pielow, 2018, translated from 
German) 

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In lignite mining, a continuous lowering of the groundwater level in the mining area is 
necessary. To reach this condition, hundreds of sump wells are often built around the 
open-cast mine, where the groundwater is sucked off by pumps. However, this lower-
ing of the groundwater often has an effect far beyond the opencast mine and can affect 
other  users.  For  this  reason,  various  measures  have  to  be  taken.  The  pumped  well 
water is used, for example, to irrigate the surrounding wetlands using infiltration plants. 
Waterworks ensure the public water supply. 

Uranium Mining  

The same principles shall apply to the extraction of uranium ores as for the extraction 
of metal ores. Examples are shown in figure 30. The uranium ore can occur in: 

•  hydrothermal lode deposits 

•  sediment deposits as well 

•  as a by-product in the extraction of other raw materials such as copper, silver, 

gold or vanadium 

In 2017, 4 % of uranium was mined in this way. Another 46 % of uranium were extract-
ed in underground or opencast mining. 

Figure 30:  Uranium mining in Romania: open cast (left, figure source: Dima 2016), and 
underground (right) 

However, half of the uranium is now extracted by so-called in-situ leaching (ISL). The 
uranium is extracted from the surrounding rock using leaching acid, and pumping the 
leached ore through drill holes. In the underground the interim storage of extracted rock 
will be done. As a mining method, there is possible a cut and fill caving with and with-
out interim storage of the waste rock and a mine filling extraction method. All uranium 
mines are under national regulatory supervision. Most of mines apply the international 
environmental  management  standard  ISO  14001  and  are  certified  accordingly.  The 
mine  operators  are  obliged  to  protect  people  and  the  environment  from  harmful  influ-
ences and to restore the natural landscape after finalization of mining operations. The 
process of certifying the social responsibility of mining companies is in progress.  

Uranium  ore  contains  up  to  0.1%  uranium  in  the  form  of  oxides.  After  ore  extraction, 
the  first  stage  of  processing  is  the  production  of  yellowcake.  Uranium  oxides  can  be 
released from the extracted ore using acids. Approximately one kilogram of yellow cake 
is extracted from two tons of ore mined in uranium mills. It consists of more than 80% 
uranium compounds. The residues from the extraction of yellowcake (so-called tailings) 
are still radioactive despite the uranium separation and must therefore be disposed of 

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in an orderly manner. The large quantity and the long half-life of the remaining thorium, 
radium and uranium isotopes present longstanding environmental problems. Contami-
nation of groundwater resources is particularly problematic. 

4.3.4  Industrial Minerals 

Industrial  minerals  refer  to  non-metallic  mineral  raw  materials  for  technical  use  and 
further processing due to their chemical or physical properties, partly only after appro-
priate processing.  Industrial minerals include salt, barite, fluorite, quartz, feldspar and 
graphite.  In  contrast  to  ores,  which  are  converted  into  metals  by  smelting,  industrial 
minerals can be used directly or with provision of small technical effort. Following raw 
materials further represent industrial minerals: 

•  potassium and magnesium salts, sea salt, potash, industrial brine, (evaporated 

salt) 

•  kaolin,  bentonite,  special  clays,  quartz,  quartz  sand  and  gravel,  phosphorous, 

diatomaceous earth, silica, molding sand, adhesive sand 

•  pegmatite sand, fluorspar, barite, graphite, sulphur, bauxite 

The available BAT document for the industrial mineral sector are: 

•  2008 BAT Guidance Note for the General Inorganic & Alumina Sector 

•  2008 BAT Guidance Note for the Glass Sector including Glass Fibre 

•  2008 BAT Guidance Note for the Ceramic & Diamond Sector 

The extraction approach of the industrial minerals is different. Potash and salt are usu-
ally extracted from larger depths (about 500 – 1,000 m and below) and they will be only 
mined underground. In addition, chamber construction, chamber pillar construction and 
offset  construction  (i.e.  chamber  construction  with  regularly  standing  pillars,  then  dis-
placement  of  the  chambers  and  subsequent  dismantling  of  the  pillars)  are  used.  The 
last-mentioned mining processes have the least possible influence on the surface envi-
ronment,  since  the  use  of  processing  waste  for  construction  eliminates  the  need  to 
transport such waste to the surface. In addition to minimizing the loss from dismantling, 
a significant improvement in fuse protection can be achieved at the same time and the 
avoidance of possible rock falls must be ensured.  

Potash and rock salt deposits are excavated and installed in a horizontal manner, with 
the shaft depth also being of particular importance with regard to subsequent renova-
tion. The shafts are largely submerged in the freezing process, which is essential when 
groundwater  resources  are  encountered.  The  underground  device  is  designed  using 
diesel  or  electric  LHD  technology  in  conjunction  with  access  ramps  to  the  respective 
mining levels. The underground extraction takes place depending on the specific host 
rock conditions 

•  drilling and blasting work (especially when there is a risk of CO2 outbreaks) or 

• 

rock-friendly machine extraction (partial cut or full cut machines) 

The  mining  technology used in these deposits is highly productive, but in case of the 
open  chamber  construction  it  means  low  output  with  high  losses  up  to  60%.  With  a 
combination  with  offset  construction,  the  deposit  losses  will  be  reduced  to  up  to  30% 

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on  one  hand,  and  on  the  other  hand,  a  significant  advantage  that  the  residue  is  only 
slightly required to be stored for days. At the same time, productivity is also declining 
on a larger scale. Salt exploration examples are illustrated in figure 31, potash wastes 
in figure 32. 

Figure 31: Salt exploration 

flotation,  cold  pre-
Conventional  processing  methods  such  as  hot  dissolving, 
decomposition  and  Electrostatic  separation  (ESTA)  are  to  be  used.  As  non-
conventional treatment processes are to be mentioned gravity separation by hydrocy-
clones, and nanofiltration. The piling up of the potash and rock salt residues is particu-
larly  negative  for  the  environment,  especially  with  regard  to  the  salinization  of  the 
groundwater and the receiving water. Extensive ecological measures are required here 
in the long term (see also section 4.6.). 

Figure 32: Surface stockpiling of potash residues 

The mining of kaolin, bentonite, special clays, quartz, quartz sand and gravel, diatoma-
ceous  earth,  silica,  molding  sand,  adhesive  sand  takes  place  in  the  mining  industry 
over days by means of the above-mentioned technologies like in aggregates extraction, 
i.e. in the form of open pit mines and quarries, depending on the size of the deposits. 
The berms are set up regularly and the alignment is carried out using ramps. The tech-
nology  is  almost  exclusively  trackless  diesel-powered  LHD  technology  combined  with 
direct extraction by excavators. Drilling and blasting technologies as extraction method 
are only used in exceptional cases. Thus, ecological challenges are: 

•  use of space for the mines to be created 

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•  placing back of processing rock and mines to be mined for the renaturation of 

land, and 

• 

influence in particular on natural water resources including their environmentally 
relevant pollution 

A  further  type  of  potash  and  rock  salt  mining  is  brine  mining.  Salt  solution  mining 
means dissolving salt resources and pumping the resulting brine to the surface where it 
is concentrated or processed to recover the desired chemical products (Warren, 2016). 
Extraction takes place via drilling (figure 33).  

Actual dissolution and recovery methodology is predicated on the solubility of the tar-
geted  salt  (Warren,  2016),  a  rough  estimation  in  the  solution  mining  industry  is  that 
every 7–8 m3 of freshwater pumped into a cavity will dissolve 1 m3 of halite. Water or 
undersaturated  brine  is  injected  through  a  purpose-designed  well  drilled  into  a  salt 
mass  to  etch  out  a  void  or  cavern  (Warren,  2016).  The  resulting  “almost  saturated” 
brine  is  then  extracted  for  processing.  The  technique  usually  targets  salts  at  depths 
greater than 400–500 m and down to 2,000 m (Warren, 2016). The resulting caverns 
can be used as natural gas storage. Table salt is usually extracted from clean sea wa-
ter in the immediate vicinity of the coast. Figure 33 illustrates the principle of brine ex-
traction by salt leaching (Warren, 2016). 

Figure 33: Principle of brine extraction by salt leaching (Warren, 2016) 

Figure 34 illustrates kaolin and clay extraction. Fluor spa and barite are usually bound 
either  to  veins  or  sedimentary  deposits,  which  are  usually  mined  in  open  pits.          
According  to  the  current  state  of  the  art,  the  removal  and  device  is  carried  out  by 
means of ramps coming from above. Following the depth, the individual mining levels 
are  connected  to  each  other  by  means  of  additional  ramps.  Extraction  technology  is 
drilling and blasting technology, the downstream production processes are carried out 

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using LHD technology. Partial cutting machines are also used for selective mining, tak-
ing into account the corresponding rock properties.  

Figure 34: Kaolin extraction (figure source: German Federal Institute for Geosciences 
and Raw Materials) 

Both barite and fluorspar are very often associated with other elements, which, howev-
er,  usually  have  a  low  concentration.  In  the  course  of  a  raw  material  strategy,  which 
requires  a  complex  use  of  all  deposit  components,  the  goal  is  to  use  these  reserves 
economically by selective extraction. The preparation is usually done by flotation. The 
aim is to place back the residues to the pit and to install them there as planned. In con-
trast to the extraction of raw materials in open-cast mines, the impact on nature and the 
temporary use of space in underground mines is minimal. Nevertheless, the operation 
of  mines  is  associated  with  negative  environmental  impacts  and  pollution  of  the 
transport infrastructure. 

4.4  General Overview on Closure Activities 

Generally, closure activities might comprise: 

•  Dismantling  of  processing  plant  and  related  structures,  steel  buildings  and 

structures, reinforced concrete buildings and structures 

•  Rehabilitation of access roads, subsided areas, and overburden and spoils 

•  Demolition  and  rehabilitation  of  electrified  railway  lines,  non-electrified  rail-

way lines, housing and facilities 

•  Opencast rehabilitation including final voids and ramps 

•  Sealing of shafts, adits and inclines, fencing 

•  Rehabilitation of processing waste deposits and evaporation ponds  

•  General surface rehabilitation, including grassing of all devastated areas 

•  River diversions 

•  Water management  

•  Maintenance and after-closure 

Table  7  provides  a  general  overview  on  the  closure  components  applicable  for  the 
types of mining. 

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Table 7: Closure components applicable for type of mine 

Main description 

Dismantling  of  processing  plant  and  related 
structures  (including  overland  conveyors  and 
power lines) 
Demolition of steel buildings and structures 
Demolition  of  reinforced  concrete  buildings 
and structures 
Decontamination  of  buildings,  plant  and 
equipment 
Rehabilitation of access roads 
Demolition  and  rehabilitation  of  electrified  rail-
way lines 
Demolition  and  rehabilitation  of  non-electrified 
railway lines 
Demolition of housing and facilities 
Opencast  rehabilitation  including  final  voids 
and ramps 
Sealing of shafts, adits and inclines 
Rehabilitation of overburden and spoils 
Rehabilitation  of  processing  waste  deposits 
and  evaporation  ponds 
(alkalinic,  salt-
producing waste) 
Rehabilitation  of  processing  waste  deposits 
and  evaporation  ponds  (acidic,  metal-rich 
waste) 
Rehabilitation of subsided areas 
General surface rehabilitation, including grass-
ing of all devastated areas 
River diversions 
Fencing 
Water  management  (Separating  clean  and 
dirty water, managing polluted water and man-
aging  the  impact  on  groundwater,  including 
treatment, when required) 
maintenance and after-closure 

Applicable closure components  
Oil  
Open- 
wells 
cast 
no 
yes 

Com- 
bination 
yes 

Under-
ground 
yes 

yes 
yes 

yes 

yes 
yes 

yes 

yes 
yes 

yes 
yes 
yes 

yes 
yes 

yes 

yes 
yes 

yes 

yes 
no 

yes 
yes 
yes 

yes 
yes 

yes 
yes 

yes 

yes 

yes 
yes 

yes 
yes 

yes 

yes 

yes 
yes 

yes 
yes 
yes 

yes 
no 

yes 
yes 

yes 

yes 

yes 

no 

yes 
yes 

yes 
yes 
yes 

yes 
yes 

yes 
yes 
yes 

yes 
yes 

yes 
yes 
yes 

yes 
yes 

no 
yes 
yes 

yes 

yes 

yes 

yes 

Closure of underground mines requires a special attention in terms of geotechnical 
stability of the mining construction and the impact of water pollution with hazardous and 
radioactive substances. 

Surface mines (open pits) need to be evaluated and rehabilitated in order to mitigate 
the  impact  on  water,  air  and  soil  and  for  safety  issues  regarding  slope  stability  and 
mine security. 

Geotechnical  stability  of  tailings  deposits  raises  complex  problems.  The  dam  and 
stockpile surface are tightly connected with the water balance, impact on underground 
water  and  generation  of  dust  on  dry  beaches.  The  rehabilitation  works  at  a  tailings 
pond will complicate even more the situation and this is the reason why it needs a care-
ful planning. 

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Tailings and salted water ponds may cause problems because of the salt load of the 
surface and underground waters. In certain situations, it requires conditioning. 

Tailing dumps can generate on long term acid water leakage which may create seri-
ous  water  pollution  problems.  Depending  on  the  tailings  material,  waste  heaps  can 
generate significant amounts of acid infiltrations. A careful planning of the dump cover 
needs to be conducted considering the water balance. 

Salt and salt bearing rock dumps can generate large amounts of salted infiltrations.  

Contaminated  buildings  (such  as  treatment  plants,  ore  bunkers)  require  demolition. 
The  wastes  resulted  need  to  be  managed  so  that  the  amount  of  wastes  requiring 
treatment or special removal methods to be reduced to minimum. 

Mine water treatment and management are critical and complex actions because of 
the time period required for water treatment. The relatively large amount of mine waters 
treated during long periods of time and the issues associated with discharging the re-
sulted  water  need  to  be  addressed  appropriately.  Standards  on  treating  the  effluents 
can offer an efficient rehabilitation solution in terms of costs. 

Sudden  breakage  of  rocks  and  underground  landslide  are  to  be  expected.  They 
will result in erosion holes and land collapse up to the surface. Moreover, the emission 
of gas may occur (CH4, CO2) and needs to be carefully monitored. These seismic activ-
ities  associated  with  mining  operations  can  be  detected  in  due  time  by  very  accurate 
geophysical measurements. 

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4.5  Closure of Aggregate Mining Sites 

4.5.1  Overview 

Usually  aggregates  mining  of  stable  rock  is  conducted  as  open  pit  mining,  in  case  of 
solid rock called quarry, excavated using one or more horizontal benches. Sand mining 
from rivers or lakes is subject dredging. Unsustainable sand dredging is often accom-
panied  by  massive  geotechnical  and  ecological  hazards.  The  closure  technique  de-
pends on the type of extraction. Dredging sites are usually left as ponds, maybe a sta-
bilisation of the slopes might be required. The further description refers to the rehabili-
tation of quarries.  

Quarrying activities create changes to topography with ongoing potential to impact the 
environment long after a quarrying activity has ceased. The restored landscape can be 
designed as agricultural land, field or meadow, forest, biotope, wetland, waste dispoal 
site,  or left to natural succession without further treatment. 

A local agreement may also be required if the proposed final land use changes the land 
use currently in force for the area or if the area is subject to planning overlaps. Once 
the final land use has been agreed, the completion criteria can be set. The mine opera-
tor must ensure that: 

a)  the rehabilitated area is left in a stable, safe, non-polluting state; 

b)  the area is suitable for the planned final use or rehabilitation objective; 

c)  rehabilitated areas are not excessively affected by erosion; 

d)  vegetation has to be consistent with the final land use. 

The operator must ensure that all obsolete and superfluous installations, vehicles, ma-
chinery  and  equipment  are  removed  from  the  working  area,  as  well  as  all  temporary 
and permanent structures, unless they are required for future use. While most part of 
the rehabilitation works should take place during the working phase of a quarry opera-
tion, some areas shall be rehabilitated after completion of the works. Proposed recla-
mation as contained in a mining plan describes a concept for the final end use of the 
site. Reclamation end uses are quite variable and may range from basic slope stabili-
zation to wildlife habitat, or even lakeshore residential development. With a concept in 
mind,  mining  activities  like  clearing,  stripping,  stockpiling,  and  landform  construction 
are directed towards final reclamation. 

4.5.2  Particular Challenges at Aggregate Mining Sites 

Usually,  aggregates  mining  sites  in  the  regular  case  do  not  contain  dangerous  waste 
according to Directive 91/689/EEC. However, it must be ensured that the site does not 
contain  blasting  or  explosive  chemical  residues.  Further,  it  must be inspected that no 
illegal waste disposal took place at the quarry site. A potential risk can occur from the 
instability of slopes, as a slope failure could lead to a serious accident. Further, aggre-
gates mining sites are usually prone to erosion. A substantial portion of quarries have a 
convex  shape  that  leads  on  the  mid-term  to  the  accumulation  of  water  (flooding  pro-
cess). In case the final after use option is not an artificial lake, the construction of water 

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diversion  channels  is  necessary.  The  area  should  be  redesigned  to  blend  in  with  the 
landscape as much as possible. Figure 35 shows a flooded aggregate quarry in Swe-
den and a closed aggregate mining site in an infrastructural landscape in Germany. 

Figure 35: Flooding of an aggregate quarry in Sweden (left); closed dry aggregate min-
ing site, included in infrastructural landscape in Germany (right) 

4.5.3  Earthworks 

A quarry should remain in a stable, free drainage condition. Objective is to reconstruct 
the  landform  to  be  compatible  with  the  surrounding  landscape  and  to  prepare  the 
ground  for  revegetation.  The  mine  operator  must  ensure  that  the  site  is  left  in  a  safe 
and stable condition. The usual closure practice is: 

•  The  reduction  of  all  slopes  to  a  gradient  of  1:3  (vertical:  horizontal)  or less, or 
application  of  artificial  slope  stabilising  means  like  geotextiles,  mulch  mats  or 
benching to break up the slope 

•  Once a stable landform has been created, respreads topsoil uniformly over the 

area at a suitable depth to support revegetation 

•  Leave topsoil with a rough surface 

The  main  earth  works  consist  of  profiling  and  stabilising  works.  During  the  closure 
works  is  necessary  to  ensure  erosion prevention, preferably through establishment of 
vegetation on a stable landform. However, as vegetation establishes, it may be neces-
sary  to  use  other  erosion  prevention  techniques.  In  order  to  decelerate  the  runoff, 
drainage controls, such as troughs, contour banks and rock filters, must be maintained 
above the area to be rehabilitated through the covering growing seedlings with surface 
mulch on steep slopes to reduce erosion, weed formation and soil moisture retention, 
and to add nutrients to the soil. 

4.5.4  Water Management 

Aggregate  mining  typically  has  less  impact  on  water  quality,  as  this  type  of  mining  is 
carried  out  without  chemicals,  and  the  target  raw  materials  rarely  contain  oxidizable 
minerals like pyrite or marcasite (Schneider & Wolkersdorfer, 2021). However, the ag-
gregates  mining  requires  sound  water  management  with  a  focus  on  water  supply  for 

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dust  control  and  sanitation  purposes  as  well  as  flood  control.  Therefore,  aggregate 
quarries  operators  usually  maintain  a  sedimentation  basin.  These  facilities  will  also 
have to be put into long term stable conditions during the closure process. Depending 
on after-closure options, water diversion channels might be required for the long term 
stable maintenance of the former aggregates site. An example is given in figure 36.  

Figure 36: Typical Drainage Plan for water management across a quarry (source: De-
partment of Economic Development, Jobs, Transport and Resources. Code of Practice 
for Small Quarries, 2010; Adapted from Quarry Code of Practice, Department of Envi-
ronment and Primary Industries Water and Environment, Tasmania 1999) 

4.5.5  Ensuring Long Term Geotechnical Stability 

The main task at aggregates mining sites is to ensure the long term geotechnical sta-
bility, particularly of the slopes. At river dredging sites, there might also occur a ground 
failure risk. Aggregates mining sites are often prone to erosion as long as no vegeta-
tion  is  established.  Further,  in  case  of  quarries,  the  slopes  can  have  sharp  edges  or 
other dangerous structures that require supplementary occupational health and safety 
installations. On high slopes, fall protection must be ensured. Another type of geotech-
nical risks are coarse rock zones shall be available for rock sliding. 

4.5.6  Ensuring Long Term Environmental Safety 

After ceasing the aggregates mining activities, all installations, vehicles, machinery and 
equipment and the substantial environmental risk decreases shall be removed from the 
working area. However, the main remaining risk results from geotechnical stability.  

Monitoring the rehabilitation works may take some time before it is determined that the 
works are safe, stable and environmentally friendly. The required level of surveillance 
may vary depending on site characteristics and the proposed final land use. 

4.5.7  After-closure: Revegetation, Flooding, Nature Protection 

Establishing a self-sustaining cover of vegetation is the best way to stabilise quarries in 
the long term. Vegetation also minimises the visual impact of quarries. Generally, the 
vegetation  type which existed before the disturbance, or a similar vegetation type will 
be regenerated most successfully. Steps to successful re-vegetation are: 

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•  Use the native vegetation originating from the local area, which is selected ac-

cording to the ecological vegetation class of a location. 

•  Sow  seed  or  plant  tubestock.  Use  of  high  quality  seeds  free  from  harmful 

weeds. 

Revegetation  may  take  several  years  to  produce  a  stable,  safe  and  self-sustaining 
ecosystem.  Any  damage  to  rehabilitation  should  be  quickly  rectified.  The  preferable 
period of species restoration is:  

•  To carry out the preparatory earthworks is in the drier months. 

•  To plant plants at a time when growth is most likely (usually autumn or spring). 
In  species  susceptible  to  frost,  however,  seeds  should  be  sown  after  the  last 
frosts. 

The  recommended  practice  is  to  inspect  rehabilitated  areas  regularly  to  assess  the 
health  of  the  vegetation  and  to  check  for  erosion,  pest  animal  browsing  damage  and 
weed infestation. In areas where germination has failed, to carry out enrichment plant-
ing of seedlings into unstocked areas or spot sowing by hand sowing of seed into small 
cultivated patches. The application of fertiliser might be useful if poor growth and yellow 
leaves indicate nutrient deficiencies. The planting of a variety of species in the vegeta-
tion with native vegetation increases the probability of success. 

Although quarries change nature and landscape, mining areas can also become eco-
logically  valuable  secondary  sites  for  many  animal  and  plant  species.  Sometimes  im-
portant  sites  for  species  and  nature  conservation  will  be developed  during the opera-
tion. A mosaic of partial and micro habitats of sun-exposed screes, precipices, niches 
and  ledges,  old  lanes  and  ponds  promotes  a  high  biodiversity  and  offers  space  for 
plants and animals with different survival strategies. Important during the mining opera-
tion  are  suitable  accompanying  measures 
managing existing operations or planning the rehabilitation of pits and quarries, there is 
a wide range of opportunities for the aggregate industry to contribute to the conserva-
tion and enhancement of biodiversity, figure 37. 

that  promote  biodiversity.  Whether        

Figure 37: Potential habitats in a) in gravel, sand, clay and clay pits (left), and b) quar-
ries (right) (Trautner & Bruns 1988, modified) 

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In case of species habitat planning, the following issues are to be considered: 

• 

Is the site within the range of any species at risk or rare habitats? It is          rea-
sonable to target the species for which there are recent records within about 20 
km of the site. 

•  Does  the  site  contain  suitable  biological,  hydrological,  and  geophysical  condi-
tions to create the desired habitat? What is the condition of existing habitat fea-
tures on the site? 

•  What are the surrounding land uses? Is the site connected to an adjacent natu-
ral  area  and,  if  so,  what  kinds  of  vegetation  are  found  in  the  intact/reference 
habitat? 

•  Are there local genetic stocks of the species at risk readily available? 

Animal translocation is strongly discouraged, unless under exceptional circumstances. 

4.6  Closure of Ore Mining Sites 

4.6.1  Overview 

Ore  mining  can  be  performed  as  opencast  or  underground  mining,  depending  on  the 
depth of the ore below surface. In addition to the geotechnical and hydrogeological site 
exploration  of  the  extraction  site,  water  management  activities  during  the  exploration 
and  site  preparation  include  the  planning  and  implementation  of  processes  for  (1)   
lowering the groundwater level, (2) disposing of groundwater and wastewater, and (3) 
planning of development of facilities for liquid and solid residues from the site (Schnei-
der & Wolkersorfer, 2021). Technical measures for the closure of ore mining sites are 
the groundwater rebound after switching off the pumps (mine flooding), the closure and 
dismantling of the mining facilities, the covering of heaps and tailings facilities and the 
reclamation of the land used for mining and their landscaping. In addition to mine clo-
sure and dismantling of facilities, placing back of excavated material and flooding of the 
mines may be required. In this case, groundwater recovery management is necessary, 
probably including water treatment (Schneider & Wolkersorfer, 2021).  

For closure techniques particularly in ore mining is to be considered the Best Available 
Techniques Reference Document for the Management of Waste from Extractive Indus-
tries,  in  accordance  with  Directive  2006/21/EC  (MWEI  BREF),  that  is  a  review  of  the 
Reference Document for Management of Tailings and Waste-Rock in Mining Activities. 
The document presents updated information on the management of waste from extrac-
tive industries, including information on BAT. It is published by the European Commis-
sion Article 21(3) of Directive 2006/21/EC on the management of waste from extractive 
industries. MWEI BREF presents data and information on the following:  

•  General information and key figures on extractive industries in Europe (Chapter 

1).  

•  Applied  processes  and  techniques  for  the  management  of  extractive  waste 

(Chapter 2).  

•  Emission and consumption levels resulting from the management of extractive 

waste (Chapter 3).  

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•  Techniques  to  consider  in  the  determination  of  Best  Available  Techniques 

(Chapter 4).  

•  Best available techniques conclusions (Chapter 5).  

•  Emerging techniques (Chapter 6).  

•  Remarks and recommendations for future work (Chapter 7). 

4.6.2  Particular Challenges at Ore Mining Sites 

During the extraction and processing of ores, liquid and solid (such as treatment resi-
dues, wastewater), waste is generated for which disposal facilities must be planned. In 
some cases, the mining residues might be toxic if the extraction or material treatment 
has  been  carried  out  with  chemicals  (Schneider  &  Wolkersorfer,  2021),  so that TMFs 
may contain toxic substances.  

For example, in the case of gold mining, cyanide  is used as a solvent; in the case of 
metal mining, acid or alkaline solutions are used (Schneider & Wolkersorfer, 2021). For 
instance,  sulphuric  acid is used for leaching of copper from oxide ore, and some sul-
phide ores. The highest volume of bulk inorganic reagents used in mineral processing 
is lime and sulphuric acid (Pearse, 2005). Lime is used for pH adjustment, coagulation, 
heavy metal precipitation, causticisation and depression of pyrite in flotation.  

Sulphuric acid is also used for pH adjustment but more importantly for the leaching of 
oxide  copper,  lateritic  nickel,  zinc  calcine,  titanium  dioxide  from  ilmenite  and  uranium 
minerals  (Pearse,  2005).  Further,  sodium  or  calcium  cyanide  (solvent  for  gold)  and 
caustic soda (pH adjustment in several processes and for the leaching of alumina from 
bauxite)  are  used  in  large  quantities.    Many  other  inorganic  reagents  are  used  in  the 
mineral  processing  industry,  even  if  in  smaller  amounts  than  those  above.  Table  8 
gives  an  overview  on  inorganic  reagents  and  their  primary  functions  in  mineral  pro-
cessing (Pearse, 2005). Those materials may be found in the TMF, depending on the 
mineral processing methodology. 

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Table 8: Some inorganic reagents and their primary functions in ore processing 
(Pearse, 2005) 

Reagent 

Sodium cyanide 

Sodium silicate 

Zinc sulphate 

Copper sulphate 

Sodium sulphite 

Primary function 

Pyrite and sphalerite depressant 

Slimes dispersant 

Sphalerite deactivator 

Sphalerite activator 

Pyrite,  sphalerite  and  oxidised  galena  de-
pressant 

Potassium dichromate 

Galena depressant 

Potassium permanganate 

Arsenopyrite and pyrrhotite depressant 

Sodium hydrosulphide 

Sulphidizer  for  oxide  and  weathered  miner-
als 

Soda ash 

Ammonia 

pH adjustment in lead flotation 

Nickel solvent 

Hydrogen peroxide 

Oxidant for gold cyanidation 

Lead nitrate 

Additive in gold cyanidation 

Alum,  Polyaluminium  chloride,  Ferric 
chloride 

Clarification 

Sodium hypochlorite 

Sodium ferrocyanide 

Cyanide destruction 

Anti-caking agent 

The pollutant-containing suspension is deposited into the TMF’s, so that the sediment 
can  settle  and  thus  forms  a  sediment  layer  with  an  excess  waste  water  level  (figure 
36).  A  special  extraction  form  is  in  situ-leaching,  where  the  acid  or  alkaline  solutions 
are pumped into the rock in order to transfer the target resource into a mobile form and 
to  extract  the  mineral  as  solution.  In  situ-leaching  sites  require  challenging  closure 
techniques  as  the  long  term  immobility  of  polluted  water  must  be  ensured.  Figure  38 
provides exemplarily impressions of TMFs in Romania, figure 39 illustrates exemplarily 
acid mine drainage in Spain. 

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Figure 38: Impressions of TMFs in Romania 

In addition, if necessary, water treatment plants might be necessary, which is particu-
larly  the  case  when  mine  water  with  elevated  concentrations  of  potentially  toxic  ele-
ments  or  acidity  is  formed  during  the  excavation  of  the  deposit  (Schneider  &  Wolker-
sorfer, 2021). Usually, this occurs when geogenic iron (di)-sulphides (pyrite, marcasite, 
pyrrhotite) are oxidized by water and oxygen; in this case, sulphuric acid reacts with the 
host rocks, forming Acid Mine Drainage (AMD, figure 37) (Evangelou & Zhang, 1995; 
Nieto et al. 2007; Wolkersdorfer, 2008; Blowes et al. 2014). 

Figure 39: Impressions of Acid Mine Drainage in Spain 

A  further  particular  challenge  at  ore  mining  sites  occurs  when  the  host  rock  contains 
geogenic radioactive material that remains as waste during processing. It is about radi-
onuclides of the natural decay series of Uranium-238, Uranium-235 and Thorium-232, 
which are represent in all rocks and ores as traces. If rocks and ores are used as raw 
materials,  natural  radionuclides  are  also  inadvertently  introduced  into  industrial  pro-
cesses. In some industries, natural radionuclides can accumulate in parts of the mate-
rial  streams.  These  residues  are  called  “naturally  occurring  radioactive  material” 
(NORM) (International Atomic Energy Agency, 2013). In the long term, this leads to a 
radioactive pollution of the environment. When using raw materials (for example ores), 
natural  radionuclides  are  generally  introduced  into  technological  processes  causing 
increased radiation exposure and radioactive residues (Technologically Enhanced Nat-

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urally  Occurring  Radioactive  Material,  TENORM).  That  material  requires  particular 
waste management practices. 

4.6.3  Closure of Open Cast Mines 

Generally, there are two approaches for the closure of opencast mines: 

a)  Filling  with  solid  material  (placing  back  extractive  waste  into  excavation  voids 

for rehabilitation and construction purposes) 

b)  Flooding with water, resulting in a pit lake. 

Filling with solid material 

Filling with solid material is often selected as solution in case a geochemical barrier of 
the waste rock is required. The advantages are (Chapman et al. 1998): 

•  Consolidating diffuse sources (multiple rock piles) into a single location; 

•  Providing a secure, maintenance free repository for potentially acid generating 

waste rock; 

•  Reducing the area impacted and increasing the area of land returned to its orig-

inal use; and, 

•  Preventing the development of an exposed acidic pit lake. 

Within  an  open  pit,  three  potential  deposition  zones  can  be  identified  in  terms  of  the 
potential  for  continued  oxidation  of  the  waste  rock,  as  shown  in  Figure  34.  A  secure 
zone  exists  below  the  re-flooded  water  table  as  oxygen  ingress  is  severely  restricted 
and thus the saturated anoxic zone represents the zone most suited for placement of 
waste rock with a high potential for acid generation. 

Above water table two additional zones do exist (Chapman et al. 1998). An oxygenated 
zone  (oxidation  zone)  exists  from  the  surface  down.  The  depth  to  which  oxygenation 
occurs depends on several factors, including diffusive transport and barometric pump-
ing. Each of these mechanisms depends on such factors such as the physical proper-
ties of the fill and the degree saturation (Chapman et al. 1998). The more reactive the 
waste  rock,  the  more  rapid  oxygen  will  be  consumed  and  the  shallower  the  resulting 
depth of oxygen entry. The third zone, (unsaturated anoxic) is delineated by the lower 
boundary of the oxygenated zone and the water table. This zone is anoxic and the po-
tential for further oxidation is limited. But, unlike the saturated zone, water flow through 
this zone generally is unsaturated so that only a small proportion of the waste rock is 
actually contacted by infiltrating water (Chapman et al. 1998). 

According  to  Paul  et  al.  (2004),  the  open  pit  mine to be  filled may be subdivided into 
sections,  but  it  will  be  difficult  to  distinguish  between  their  relative  effects.  Water  flow 
consists of infiltration respectively groundwater recharge in the open pit area (preferen-
tially  vertical  flow),  groundwater  flow  through  higher  permeable  areas  (aeration  zone, 
inside dump) due to hydraulic gradients and despite the hydraulic connection provided 
by  the  mine  workings,  as  well  as  exchange  of  substances  between  the  well  flowed 
through aeration zone surrounding the open pit and the filled waste rock in the pit. Fig-
ure 40 illustrates the conceptual zonation of filled open pit (Chapman et al. 1998) and 
the practical example of the open pit Lichtenberg, Germany in 2004, that was filled with 

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conceptual  zonation.  In  the  foreground  are  visible  hydrological  test  sites  for  the  final 
surface cover (Hoepfner & Schneider, 2006). 

Figure 40: Conceptual zonation of a filled open pit (Chapman et al. 1998) (left); open pit 
Lichtenberg, Germany (2004), filled with reactive zones (right) 

Flooding with water, resulting in a pit lake  

The flooding process happens because the drainage wells or dewatering pumps stop 
to work and the open mining spaces are filled with ground and surface water. Flooding 
the open cast mine with water means also to allow for precipitation to enter the open 
case mine, and/or to provide supplementary water from other sources. Usually, in case 
of solid rock pen cast mines, as sources might be used water diversion channels from 
natural creeks, in case access water might be diverted. In case of flooding with surface 
water,  protection  of  the  natural  water  courses  according  to  EC  Water  Framework  Di-
rective must be ensured. Figure 41 shows a sample of a flooded copper mine in Bul-
garia. 

Figure 41: Sample of a flooded copper mine in Bulgaria (left); water diversion channel 
upstream the mine (right) 

A flooding strategy strongly depends on the after-closure usage scenario and the avail-
able water sources. 

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4.6.4  Closure of Underground Mines 

Closure of open mine workings 

Two general filling approaches are applied for underground mines, resulting in follow-
ing closure techniques: 

a)  Filling with solid material  

b)  Flooding  with  water,  resulting  in  a  raising  groundwater  level  and  a  mixture  of 
mine and groundwater. A flooding water level might result in an outcrop. In such 
a case, adits are necessary for mine water management.  

Filling with solid material 

Regarding the filling with solid material, there are many requirements in terms of quality 
because this affects mining cost, performance  of the mining equipment and the filling 
ratio,  e.g.  binder  vs.  rocks  (Zhang  et  al.  2019).  Further,  the  selection  of  materials  for 
filling and its mixture design is essential, as well as a close-by source of the  materials 
(Zhang  et  al.  2019).  Figure  42  provides  an  overview  on  engineering  demands  for  se-
lecting materials for filling.  

Figure 42: Engineering demands for selecting materials for filling (Zhang et al. 2019) 

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The provision of filling material is done through an open mine working like a shaft or an 
adit.  Depending  on  placement  and  consistency  of  the  fill  material,  the  following  types 
can be distinguished (Konietzky, 2018): 

•  Pneumatic filling: dry material is placed via pneumatic conveying through pipes 

•  Hydraulic filling: liquid material is placed via pipes, belts or trucks 

•  Paste filling: pasty material with high solid content (> 65%) transported through 

pipes by hydraulic pressure 

•  Mechanical  filling:  dry  granular  material  is  placed  via  belts,  chutes,  pipes  or 

trucks in the excavations (just gravity driven) 

•  Big bags: filled with dry or only slightly wetted material are placed in the excava-

tions. 

There are further differences between cemented and uncemented material (Konietzky, 
2018). The first one can be transported and placed by gravity or pumping, the second 
one by pneumatic or slinger stowing. 

Flooding with water  

Flooding in underground mines is usually controlled. These types of mines are not di-
rectly influenced by surface waters, so it is mainly underground water that plays a role 
in  the  flooding.  One  of  the  main  reasons  to let an underground mine be flooded is to 
avoid  disulphide  oxidation  and  thus,  avoid  acid  mine  drainage.  In  case  flooding  with 
water takes place, stable bedrock is a precondition. Flooding means to cut off the op-
eration of the pumps that keep water out of the mine and to allow groundwater to rise. 
Shafts  and  other  mine  workings  act  as  preferential  flow  paths  in  this  case,  and  the 
permeability  is  much  higher  than  before  the  mining  activities.  Flooding  of  mines  re-
quires  a  comprehensive  mine  water  management.  The  controlled  flooding  of  under-
ground mines usually follows these guidelines: 

•  Removal of potential water hazards 

•  Fill the surfaces that might collapse during or after the flooding process 

• 

• 

Install water diversion systems 

Install, at both the surface and underground, a system to monitor hydrogeologi-
cal and geotechnical aspects 

•  Make  a  projection  of  hydrological  and hydrogeochemical development of mine 

waters 

Figure  43  shows  a  mine  flooding  scheme,  illustrated  at  the  Schlema-Alberoda  site, 
Germany (Schneider et al. 2005). 

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Figure 43: Mine flooding scheme of the Schlema-Alberoda site, Germany (Schneider et 
al. 2005) 

Closure of mine openings 

Mine openings must be kept permanently and securely at the end of their useful life to 
avoid damage to the surface of the day and in the interest of public security. A distinc-
tion is made: 

Ensuring permanent safety 

Permanent safety measures over a limited period (years / decades) eliminate or signifi-
cantly reduce the risk to public security. Periodic inspections or monitoring are an inte-
gral  part  of  these  rehabilitation  measures  (e.g.  plumbing  the  fill  level  and,  if  neces-
sary)The inspection by the competent authority will be continued all the period. 

Definitive final long term closure 

Permanent, effective and maintenance-free measure to prevent adverse effects on the 
surface  of  the  site  and  rehabilitation  of  existing  damages.  The  scope  and  type  of 
measure must be adapted to the existing or planned use of the site surface. The clo-
sure design must ensure an efficiency of more than 100 years. The inspection by the 
competent authority will end after a certain period after approval of implementation. 

Visible  mine  openings  include  shafts,  adits  and  sinkholes.  Abandoned  and  unsafely 
secured  mine  openings  are  an  acute  hazard  to  people.  Shafts  have  to  be  stabilised 
and inadvertent access prevented to avoid danger to the surface and to ensure public 
safety  when  mining  activities  have  ceased.  Figure  44  illustrates  samples  of  shafts,   
adits, and sinkholes before rehabilitation. 

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Figure 44: Sample of shafts (left); adits (centre) and sinkholes (right) before rehabilita-
tion 

Before  planning  and  executing  shaft  safekeeping,  preliminary  examinations  must  be 
carried out to determine the type of safekeeping: 

•  Analysis of the mine survey documents and the technical information 

•  Analysis of mining damage 

•  Geological and geotechnical surveys 

•  Hydrological studies 

Shafts contain two parts that must be closed: the shaft hole (drilling hole) and the mine 
opening (shaft mouth). Generally, shafts have to be stabilised by total or partial filling 
(waste  rock,  crushed  rock  or  cohesive  material).  Shafts,  that  are  located  in  predomi-
nantly or completely in the coarse bed rock or in the non-stable solid rock must be filled 
to their full depth. Shafts in the stable, solid bed rock must be rehabilitated by partial or 
full filling according to the specific conditions. 

Shaft hole 
Depending  on  the  site  setting,  the  following  materials  are  generally  permitted  for  the 
filling of shafts: 

•  Broken bedrock: crushed stone, grit 

•  Non-cinder coarse rock: gravel, sands 

• 

Industrial mineral waste products: waste rock material, slags, ashes 

•  Cohesive  filling  material:  erosion  and  position-stable  hydraulically  setting  ce-
ment-bound materials (concrete, hardening mix using cement and officially ap-
proved brown coal filter or power plant ash as a binder) 

All  internals  that  prevent  the  intended  filling  sections  from  being  completely  filled  and 
which can break when the filling material is introduced must be taken out beforehand, 
provided  that  they  have  no  expansion  function.  The  permissible  fall  heights  for  cohe-
sive contents are to be determined depending on the material properties (consistency, 
grain size of the additives). Figure 45 shows general option for shaft hole closure. 

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Figure 45: Shaft closure: a) full filling: cohesive filling column (left); b) full filling: coarse 
rock filling column combined with cohesive filling column section (centre), and c) partial 
filling: sealing and coarse rock filling column combined with cohesive filling column sec-
tion (right) 

In  order  to  avoid  settlement  of  the  filling  column,  sands  with  approx.  5%,  waste  rock 
with approx. 15% as well as flotation piles and ashes with approx. 30% water content 
should be added to the dry batch volume if there is no water in the shaft to the appro-
priate extent or if it is filled into water.  

Strength requirements: 

Filling  columns  reaching  from  the  deepest  of  the  shaft  to  the  surface:  Compressive 
strength of the filling material after 28 days σD ≥ 2 MN / m² as a minimum requirement, 
stipulations of σD ≥ 5 MN / m² have proven successful for the filling column sections in 
the area of filling locations and σD ≥ 2 MN / m² for the filling column areas in between.. 

Cohesive filling column sections: Definition of the required quality features according to 
the following criteria: length or height of the filling column, shaft cross-section, size of 
changes  in  cross-section  of  the  shaft  with  depth,  type  and  properties  of  the  shaft  ex-
tension  or  rock,  strength  properties  of  the  shaft  expansion  and  rock,  load size on the 
filling column. 

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Filling columns must always be permanently secured against leakage into unfilled shaft 
areas, filling point or other shaft exits. The Best Practice of securing coarse rock filling 
columns is: 

1. Sealing 

Use as partial filling, applicable in stable bedrock, not applicable in active subsidence 
areas, as well as in areas affected by mining and with water inflows >1 m³/min.  

Types:  Sealing  in  the  shaft  pipe  (e.g.  concrete  single  shear  plug,  concrete  double 
shear plug), sealing in one filling location (e.g. solid filling location double seal, massive 
filling  location  single  seal,  solid  plate  with  conical  abutments  in  connection  with  filling 
location embankments made of gravel or with other shut-off devices) 

2. Shut-off devices in filling locations 

Fully offset zones, explosive fracture zones, dams made of masonry or concrete 

3. Filling locations 

Shut-off  devices  in  filling  locations  to  secure  the  filling  column  can  be  omitted  if  it  is 
possible  to  pour  filling  location  embankments  out  of  gravel.  Ballast  must  be  made  of 
weatherproof and water-resistant material. As a guideline, a grain size of 80 mm should 
be aimed for (e.g. crushed stone 56/80). 

The prerequisite for this method is that the shaft be blocked off at the level of the shaft 
outlet in question by means of a solid plate or that the part of the shaft pipe underneath 
is filled and that the height of the ballast column height can be reliably verified during 
and at the time the ballast insertion is completed  

Shaft entrance 

According to the current state of the art, following methodologies are used for closure 
of abandoned shaft mouths 

•  walling of the immediate mouth area 

• 

filling if an approx. 10 m long section in the mouth area 

•  closing the mouth hole by blasting 

If sinkholes occur in the surrounding of the adit, the relevant areas must be secured as 
soon as possible without any voids. A common method is the introduction of concrete 
offset through holes. 

The following rehabilitation measures can be applied:   

•  Excavation  of  a  building  pit,  stabilisation  of  the  shaft  by  infilling  rock  material 

and sealing with a reinforced concrete plate,   

•  Construction of a concrete shear plug inside the shaft, secured against slipping, 
within reach of the shaft surface, followed by filling of the upper part of the shaft 
with crushed rock up to the surface. 

The option of fencing-in an object and installing hazard warning signs should be con-
sidered a temporary measure. This is a rapid but unsustainable hazard prevention with 
minimum budget. The method of shaft sealing with a reinforced concrete plate is illus-
trated in Figure 46. 

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Figure 46: Shaft mouth sealing with reinforced concrete plate (left); shaft sealing with 
concrete shear plug (right) 

Horizontal  mine  access  structures,  inclines,  adits  and  shaft  entrances,  are  usually 
sealed soon after closure for reasons of public safety. The applicable closure technolo-
gy depends on: 

• 

location of the adit with reference to the surface, 

•  geological and hydrogeological setting, 

•  adit function, and 

•  general state of the adit in terms of stability and accessibility. 

If the adit serves or may serve as a mine water conduit, special attention has to be paid 
to a stable water discharge. Following settings are typical situations in terms of adit or 
shaft mouth closure: 

•  adit or shaft entrance open, no seepage water drainage 

•  adit or shaft entrance open, seepage water drainage 

•  Open adit, no water leakage, sinkholes along the adit route 

•  broken or filled up adit, seepage water drainage 

The closure technology is illustrated in figures 45 and 46. 

For closure of adits the following measures are in compliance with applicable interna-
tional standards, guidelines and best practice:   

•  construction of a solid brick or concrete wall at the entrance of the adit (possibly 

followed by crushed rock/soil filling in the front section) 

•  blocking of a 10-50 m long section immediately behind the adit portal with cohe-

sive fill 

• 

filling of the complete adit and closure of the mouth of the adit by blasting 

•  gravel filling at the adit portal 

The method of adit sealing with a brick wall and filling with crushed rock and soil is il-
lustrated in Figures 47 and 48. The standard construction measures include: 

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•  Excavation of soil in front of the adit if necessary, 

• 

Install a brick wall of 0.5 m thickness and install a drainage pipe if necessary, 

•  Filling crushed rock and soil in front of the adit. 

Figure 47: Adit sealing with a) brick wall and filling with crushed or waste rock (left), b) 
with fluid concrete (centre), and c) blasting or pouring with waste rock or crushed roc.  

In case of water flow, the solutions displayed in figure 47 need to be equipped with a 
drainage pipe to ensure dewatering from the mine workings (figure 48). 

Figure 48: Adit or shaft mouth closure with brick wall and drainage pipe with siphon 
(left); adit or shaft mouth closure with fluid concrete and drainage pipe with siphon 
(right) 

Sinkholes are caused by collapsing underground mine workings. Sinkholes should be 
filled  and  stabilised  in  order  to  prevent  people  from  falling  in.  Long-term  stable  solu-
tions  should  be  applied  to  prevent  underground  workings  from  continued  caving  in. 
Information about the underground mine workings are helpful to ensure proper closure.  
The following options are applicable for securing sinkholes:  

•  Fill with waste rock 

•  Construction of a concrete plug at the surface of a sinkhole 

The concrete plug close to the surface is best practice of sinkhole rehabilitation in hard 
rock. Loose material is excavated down to the level of hard rock. Then abutments are 
inserted into hard rock to establish holding forces for the concrete plug. The void above 
the concrete is filled with natural soil. A sketch of this option is presented in Figure 49.   

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Figure 49: Sinkhole sealing with concrete plug close to the surface (left); filling with 
waste rock (right) 

4.6.5  Management of Solid/liquid Control of Extractive Waste 

In order to help ensure the physical stability of extractive waste, BAT is to use one or a 
combination of techniques, appropriately selected from the following list (MWEI BREF): 

•  Mechanical  screening  -  Relevant  for  extractive  waste  from  excavation  and  ex-
tractive waste from mineral processing; particularly relevant for extractive waste 
from mineral processing to be deposited into ponds 

•  Hydro-cycloning - Relevant for extractive waste from mineral processing; partic-
ularly relevant for extractive waste from mineral processing to be deposited into 
ponds 

•  Thickening  and  clarifying  -  Relevant  for  extractive  waste  from  mineral  pro-
cessing; particularly relevant for extractive waste from mineral processing to be 
deposited into ponds; particularly relevant for extractive waste from alumina re-
fining (red muds) 

•  Dewatering by means of a pressure gradient or a centrifugal force - Relevant for 
extractive  waste  from  mineral  processing;  particularly  relevant  for  extractive 
waste from mineral processing to be deposited into ponds; particularly relevant 
for extractive waste from alumina refining (red muds) 

4.6.6  Extractive Waste Stabilisation  

In order to help ensure the physical stability of extractive waste, BAT is to use one or a 
combination of techniques, appropriately selected from the following list (MWEI BREF): 

•  Preparing cemented coarse extractive waste to be placed back into excavation 

voids  

•  Preparing  extractive  waste  slurry  (uncemented  and  cemented)  to  be  hydrau-

lically placed back into excavation voids  

•  Preparing paste extractive waste to be placed back into excavation voids 

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4.6.7  Compaction, Consolidation and Deposition of Extractive Waste 

In order to help ensure the physical stability of extractive waste, BAT is to use one or a 
combination of techniques, appropriately selected from the following list (MWEI BREF): 

•  Thickened/ paste extractive waste subaerial deposition - Relevant for extractive 

waste from mineral processing 

•  Wet or dry filter cake deposition (or dry stacking) - Relevant for extractive waste 
from mineral processing; particularly relevant for extractive waste from alumina 
refining (red muds) 

•  Placing  extractive  waste  back  into  excavation  voids  -  Relevant  for  non-

hazardous extractive waste 

•  Mud farming - Relevant for extractive waste from alumina refining (red muds) 

•  Co-disposal  of  fine  and  coarse  fractions  of  extractive  waste  -  Relevant  for  ex-
tractive waste from excavation Relevant for extractive waste from mineral pro-
cessing. 

4.6.8  Prevention or Minimisation of Pollutant Leaching 

In order to help ensure the chemical stability of extractive waste, BAT is to use one or a 
combination of techniques, appropriately selected from the following list (MWEI BREF): 

•  Reduction of extractive waste alkalinity - Relevant for extractive waste with high 
alkalinity;  particularly  relevant  for  extractive  waste  from  alumina  refining  (red 
muds) 

•  Compaction,  consolidation  and  deposition  of  extractive  waste  -  Relevant  for 

non-inert extractive waste 

•  Progressive rehabilitation - Relevant for non-inert extractive waste 

•  Temporary covers - Relevant for non-inert extractive waste 

4.6.9  Prevention or Minimisation of Acid Rock Drainage (ARD) 

In order to help ensure the chemical stability of extractive waste, BAT is to use one or a 
combination of techniques, appropriately selected from the following list (MWEI BREF): 

•  ARD management system - Relevant for Potentially Acid Generating (PAG) ex-

tractive waste 

•  Segregation of PAG and Non Acid Generating NAG extractive waste by sorting 

and selective handling/ deposition - Relevant for PAG extractive waste 

•  Desulphurisation - Relevant for PAG extractive waste 

•  Blending with buffering materials - Relevant for PAG extractive waste 

Furthermore (Relevant for PAG extractive waste): 

• 

• 

Impermeable natural soil basal structure 

Impermeable artificial basal structure 

•  Progressive rehabilitation 

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•  Temporary covers 

• 

Impermeable and low-flux dry covers 

•  Oxygen consuming dry covers 

•  Free water covers 

•  Wet covers 

4.6.10  Prevention or Minimisation of Self-ignition of Extractive Waste 

In order to help ensure the chemical stability of extractive waste, BAT is to reduce the 
combustible  matter  content,  to  compact  the  extractive  waste  using  appropriate  me-
chanical  equipment  and/or  to  carry  out  landscaping  and  geomorphic  reclamation 
(MWEI BREF). 

4.6.11  Reduction of Dangerous Substances in Extractive Waste 

Measures for reduction of dangerous substances in extractive waste might refer to the 
reduction  of  the  cyanide  concentration  in  ponds  or  to  the  reduction  of  hydrocarbon 
concentrations in drilling extractive wastes (MWEI BREF). 

4.6.12  Minimisation of Groundwater Status Deterioration and Soil Pollution 

In order to prevent or minimise groundwater status deterioration and soil pollution, BAT 
is to use one or a combination of techniques, appropriately selected from the following 
list (MWEI BREF, amended by the authors): 

Basal structures and physical barriers 

• 

• 

Impermeable natural soil basal structure - Relevant for ponds, dams and heaps 
Relevant for non-inert extractive waste 

Impermeable  artificial  basal  structure  -  Relevant  for  ponds,  dams  and  heaps 
Relevant for non-inert extractive waste 

•  Seepage barriers - Relevant for ponds, dams and heaps Relevant for non-inert 

extractive waste 

•  Lining  the  surface  for  temporary  storage  of  drilling  muds  and  other  extractive 
wastes - Relevant for drilling muds and other extractive wastes from oil and gas 
exploration and production, including flowback and produced water 

•  Temporary  storage  of  drilling  muds  and  other  extractive  wastes  in  containers 
/tanks - Relevant for drilling muds and other extractive wastes from oil and gas 
exploration and production, including flowback and produced water. 

Water streams management 

•  Diversion of water run-off systems 

•  Drainage systems for ponds and dams 

•  Drainage systems for heaps 

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•  Landscaping and geomorphic reclamation 

Covering 

•  Progressive rehabilitation - Relevant for ponds, dams and heaps and for exca-

vation voids where extractive waste is placed back 

•  Temporary covers - Relevant for ponds, dams and heaps, for excavation voids 

where extractive waste is placed back and for temporary storage 

•  Vegetative  covers  -  Relevant  for  ponds,  dams  and  heaps  and  for  excavation 

voids where extractive waste is placed back  

•  Permanent dry covers  

o  Permeable dry covers - Relevant for ponds, dams and heaps and for ex-
cavation voids where extractive waste is placed back, Relevant for cov-
ering non-hazardous extractive waste 

o 

Impermeable  and  low-flux  dry  covers  -  Relevant  for  ponds,  dams  and 
heaps and for excavation voids where extractive waste is placed back, 
Relevant for covering non-inert extractive waste 

o  Reactive covers - Relevant for ponds, dams and heaps 
o  Oxygen-consuming  dry  covers  -  Relevant  for  ponds,  dams  and  heaps 
and  for  excavation  voids  where  extractive  waste  is  placed  back,  Rele-
vant for covering PAG extractive waste 

•  Permanent wet covers  

o  Free  water  covers  -  Relevant  for  ponds  and  dams  and  for  excavation 
voids where extractive waste is placed back, Relevant for covering PAG 
extractive waste 

o  Wet  covers  -  Relevant  for  ponds  and  dams  and  for  excavation  voids 
where  extractive  waste  is  placed  back,  Relevant  for  covering  low-PAG 
extractive waste or low paste PAG extractive waste 

4.6.13  Closure of Tailings Management Facilities 

General considerations 

TMF  rehabilitation  is  a  challenge  during  the  whole  mine  closure  process,  as  the  fine 
sediments are not always settled after the mine due to strong pore water pressure. In 
most cases, tailings consist of fine-grained material (a few micrometres to sand grain 
size)  that  has  been  disposed  of  in  slurry  form  above  ground.  For  tailings  dams,  the 
standard  engineering  aspects  (dam  stability,  water  diversion)  as  well  as  chemical  as-
pects have to be considered. Figure 49 shows a typical TMF to be closed. 

The planning of tailings dams is carried out according to the recommendations of the 
International  Commission  on  Large  Dams  (ICOLD)  that  issues  the  bulletin  on  dam 
safety  management.  ICOLD  is  an  international  non-governmental  organization  aiming 
to  the  sharing  of  professional  information  and  knowledge  of  the  design,  construction, 
maintenance, and effects of large dams (any dam above 15 m in height), and leads in 
setting  standards  and  guidelines  to  ensure  that  dams  are  built  and  operated,  having 
presently  30  Technical  Committees.  ICOLD  Technical  Committees  are  issuing  bulle-

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tins, that are a “state of the art” with recommendations for engineers for ensuring ge-
otechnical and environmental long-term stability, also for tailings pond dams (Bowles et 
al.  2007).  Depending  on  the  dimension  of  the  mining  site  and  extension  of  the  pro-
cessing activities, TMFs can reach a dimension of up to several hectares and a thick-
ness of several tens of meters. They contain the processing sludge that is undergoing 
sedimentation  and  thus  get  separated  into  a  solid  and  a  liquid phase, which is called 
pore water or interstice water and, usually, polluted through processing residues.  

From geotechnical point of view, the dam structure of the ponds needs to be assessed 
as  well  as  the  function  of  water  diversion  channels,  which  might  be  dilapidated  after 
decades. From the knowledge of the current state remedial options can be elaborated. 
The following general remedial options for tailings ponds are: 

• 

In-situ  rehabilitation:  Dams  need  to  be  stabilized  to  withstand  all  hydraulic  or 
seismic conditions. A proper water discharge has to be installed. After dewater-
ing a properly engineered cover has to be installed onto the tailings. 

•  Offsite  rehabilitation:  This  option includes the excavation of tailings, dams and 
contaminated  ground.  The  material  must  be  transported  to  a  suitable  site  and 
installed there. At the storage site the same measures are necessary as need-
ed for in-situ rehabilitation.   

Figure 50 shows a typical TMF to be closed, a sample of a copper mining site in Bul-
garia. 

Figure 50: Typical TMF to be closed; sample of a copper mining site in Bulgaria 

Usually, before any closure activities can start, the tailings body must be consolidated 
and dewatered to ensure geotechnical stability.  

Geotechnical stabilisation – Dewatering 

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To ensure long term safety of tailings ponds, a methodology using verticals drains has 
been developed. It is usually necessary to be applied before the establishment of dry 
covers in case the settling process of the tailings is not finalised. In most instances, the 
first step in the reclamation of TMFs is to drain the pore water from the tailings and to 
cover the waste and tailings storage facilities. Polluted pore water is treated in a waste 
water treatment plant. Figure 51 provides an overview on an active tailings pond, and a 
tailings  pond  under  forced  consolidation  through  subaquatic  fill  of  extractive  waste 
through  hopper  barge.  Figure  52  illustrates  the  application  of  vertical  drains  through 
drilling  and  the  TMF  stabilisation  through  geogrid,  underlain  by  geofabric  and  drain 
mats. 

Figure 51: Overview on active tailings pond (left);  tailings pond under forced consolida-
tion through subaquatic fill of extractive waste through hopper barge (right) 

Figure 52: Application of vertical drains through drilling (left); TMF stabilisation:       ge-
ogrid, underlain by geofabric and drain mats (right) 

TMF Covering 

After  geotechnical  stabilisation  of  the  tailings  material,  the  tailings  pond  can  be  cov-
ered. In terms of in-situ rehabilitation, and according to MWEI BREF, permanent wet or 
dry covers can be applied. A dry cover is a cap-and-cover solution to cover extractive 
waste  with  a  single  soil  layer  or  a  layered  structure  of  numerous  soils,  natural  and/or 
artificial materials (such as geosynthetics). A wet layer is a permanent water cap. The 
applicable covers according to MWEI BREF are given below: 

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Permeable dry covers: consists of covering the extractive waste with a single layer or 
multiple  layers  of  soil  or  equivalent  materials  permeable  to  water  and  oxygen,  while 
ensuring that the use of such a layer or layers does not lead to any additional adverse 
environmental or human health impacts (MWEI BREF). 

Impermeable and low-flux dry covers: consist of covering the extractive waste with 
multiple functional layers in order to inhibit the oxygen influx, to limit the meteoric water 
infiltration,  and  the  degassing  of  pollutants  like  radon  (in  case  of  uranium  mining) 
(MWEI BREF, amended by the authors). This type of covers includes mineral sealing 
layers, geomembranes, bentonite mats, and asphalt (Kudla et al. 2009) sealing layers. 
Recent  investigations  underline  that  the  only  sealing  systems  that  impermeable  for 
(radioactive) gas convection are quality assured systems with geomembranes or bitu-
men, respectively asphalt.  

Oxygen-consuming dry covers: consists of using organic materials for covering PAG 
extractive waste to consume oxygen and reduce its infiltration (MWEI BREF). 

Free  water  covers:  is  a  closure  method  where  extractive  waste is covered by a free 
water  layer  in  order  to  isolate  contaminants  and  reduce  erosion,  dusting  and  oxygen 
infiltration (MWEI BREF). 

Wet covers: consist of allowing water to infiltrate the extractive waste, thus forming a 
wet  cap  on  the  top, and adding organic matter, to enhance the establishment of wet-
land vegetation in the pond (MWEI BREF). 

4.6.14  Closure and Covering of Waste Rock Heaps 

The  rehabilitation  approach  of  waste  rock  heaps  depends  on  the  pollution  potential. 
While  sites  with  lower  pollutant  potential  are  often  not  surface  sealed  (Ludwig  et  al, 
2003)  and,  as  a  preferred  solution,  are  often  left  to  be  rehabilitated  by  natural  plant 
succession (Sweigard et al. 2017), waste rock heaps with higher pollutant potential or 
in close proximity to protected areas usually need to be covered (Sweigard et al. 2017). 
A  further  after-use  for  biomass  production  might  also  be  taken  into  consideration  for 
sites with a small pollution potential that are left to natural plant succession (Bungart et 
al. 2000). For sites that require a mineral sealing, this sealing may involve a hydraulic 
barrier  (mineral  sealing  layer  with  a  permeability  coefficient  of  <  1  ×  10-9  m/s  and  a 
thickness  of  about  50  cm),  or  pure  mineral  layers,  which  form  a  gas  and  dust  barrier 
and serve as root space for plants. A special solution for waste rock hepas with a very 
high pollutant potential can be reactive horizontal barriers (Schneider et al. 2002). 

Waste rock hepas often consist of a plateau area (close to a shaft or adit) and a slope 
area  with  the  natural  angle  of  repose.  Geomechanical  risks  may  occur  if  such  heaps 
slopes are located very close to residential areas which might be affected by e.g. rock-
fall. However, in the most cases mine waste heaps are relatively stable objects consist-
ing of coarse material. From a radiological point of view waste rock dumps pose only in 
rare cases a risk to human. Independent of the risks, the general remedial options for 
waste rock heaps are: 

•  Fencing areas in and warning signs 

• 

In-situ rehabilitation with sub-options such as: 

o  Local measures against rockfall 

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o  Local geomechanical strengthening of the waste rock heap 
o  Local measures against water erosion 
o  Reshaping/flattening parts of the waste rock heap 
o  Covering the waste rock heap 

•  Relocation of waste rock to a more appropriate area and potentially covering of 

the new disposal site 

•  Covering:  typically,  permeable  dry  covers,  Impermeable  and  low-flux  dry  co-
vers, or Oxygen-consuming dry covers (MWEI BREF) are designed, depending 
on the extractive waste type and its hazard potential. Often mineral sealing lay-
ers are applied, sometimes in combination with geomembranes. 

Figure 53 Illustrates a mineral sealing layer on waste rock heaps, and the concept of a 
reactive  horizontal  barriers  (Schneider  et  al.  2002).  Reactive  barriers  might  be  also 
used for the closure of PAG waste heaps. 

Figure 53: Mineral sealing layer on waste rock heaps (figure source: Wismut GmbH, 
left) and a reactive horizontal barriers (right, Schneider et al. 2002) 

Further  new  developments  in  terms  of  base  and  surface  sealing  elements  include 
Tektoseal,  a  reactive  lining  system  that  is  amended  with  active  geo-composites  like 
sodium bentonite granules or active coal. 

4.6.15  Groundwater and Soil Pollution Remediation 

In order to minimise groundwater status deterioration and soil pollution, BAT is to use 
one  or  a  combination  of  techniques,  appropriately  selected  from  the  following  list 
(MWEI BREF, amended by the authors): 

•  Permeable Reactive Barriers (PRBs) - Relevant for PAG extractive waste or for 

extractive waste with metal leaching potential 

•  Funnel  and  Gate  -  Relevant  for  PAG  extractive  waste  or  for  extractive  waste 

with metal leaching potential 

•  Phyto-Technologies - Relevant for PAG extractive waste or for extractive waste 

with metal leaching potential 

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• 

• 

In-situ Chemical Oxidation (ISCO) - Relevant for PAG extractive waste or for ex-
tractive waste with metal leaching potential 

In-situ  Chemical  Reduction  (ISCR)  -  Relevant  for  PAG  extractive  waste  or  for 
extractive waste with metal leaching potential 

•  Anoxic Limestone Drains / Reducing and Alkalinity Producing Systems (RAPS) 
in shafts and adits - Relevant for PAG extractive waste or for extractive waste 
with metal leaching potential 

•  Bioscreens, Bioventing, Biosparging - Relevant for PAG extractive waste or for 

extractive waste with metal leaching potential 

4.6.16  Surface Water Pollution Remediation 

In order to prevent or minimise surface water status deterioration, BAT is to use one or 
a  combination  of  techniques,  appropriately  selected  from  the  following  list  (MWEI 
BREF, amended by the authors): 

•  Oxidation-based systems 

o  Aeration  and  active  chemical  oxidation  -  Relevant  for  Extractive  Waste 
Influenced Water (EWIW) containing Total Dissolved Substances (TDS) 

o  Active  aerobic  biological  oxidation  -  Relevant  for  EWIW  containing  bio-

logically oxidisable TDS 

o  Aerobic wetlands - Relevant for EWIW containing TDS 

•  Reduction-based systems using bacterial activity 

o  Anaerobic  wetlands  -  Relevant  for  EWIW  containing  TDS,  particularly 

relevant for treating ARD 

o  Anoxic  BioChemical  Reactors  (BCRs)  -  Relevant  for  EWIW  containing 

TDS, particularly relevant for treating ARD 

•  Chemical precipitation 

o  Hydroxide and carbonate precipitation - Relevant for EWIW contain-
ing TDS, particularly relevant for EWIW containing dissolved metals 

o  Sulphide precipitation - Relevant for EWIW containing TDS, particu-

larly relevant for EWIW containing dissolved metals 

•  Co-Precipitation 

o  Co-precipitation  with  chloride  or  sulphate  metal  salts  -  Relevant  for 
EWIW containing TDS, particularly relevant for EWIW containing ra-
dium-226 

•  Adsorption 

o  Adsorption - Relevant for EWIW containing TDS 

• 

Ion exchange 

o 

Ion exchange - Relevant for EWIW containing TDS 

•  Filtration of dissolved substances 

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o  Nanofiltration - Relevant for EWIW containing TDS 
o  Reverse Osmosis - Relevant for EWIW containing TDS 
o  Membrane Biorector (MBR) - Relevant for EWIW containing TDS 

•  Neutralisation of EWIW prior to discharge - Active treatment 

o  Active neutralisation - Relevant for acidic or alkaline EWIW 

•  Neutralisation of EWIW prior to discharge - Passive treatment 

o  Oxic  Limestone  Drains  (OLDs)/Open  Limestone  Channels  (OLCs)  - 

Relevant for acidic EWIW 

o  Anoxic Limestone Drains (ALDs) - Relevant for acidic EWIW 
o  Successive Alkalinity-Producing Systems (SAPS) - Relevant for acid-

ic EWIW 

o  Anaerobic wetlands - Relevant for acidic or alkaline EWIW 

4.6.17  Prevention or Minimisation of Dusting of Extractive Waste 

In  order  to  prevent  or  minimise  air  pollution,  BAT  is  to  use  one  or  a  combination  of 
techniques, appropriately selected from the following list (MWEI BREF): 

•  Water or water-based solutions spraying - Relevant for exposed surfaces of ex-

tractive waste 

•  Wind protection systems - Relevant for exposed surfaces of extractive waste 

•  Landscaping and geomorphic reclamation - Relevant for exposed surfaces, rel-

evant for NAG extractive waste 

•  Progressive rehabilitation - Relevant for exposed surfaces 

•  Temporary covers - Relevant for exposed surfaces 

•  Vegetative covers - Relevant for exposed surfaces 

•  Permanent wet covers - Relevant for exposed surfaces 

4.6.18  Decommissioning of Buildings and Processing Plant Areas 

Remedial options for the buildings and areas comprise the following options: 

•  Fencing the buildings or processing areas in and install warning signs 

• 

In-situ  rehabilitation  with  demolition  of  the  buildings  and  local  disposal  of  the 
debris 

•  Offsite rehabilitation with demolition of the buildings and transport of debris to a 

proper disposal site. 

The second and third options comprise only demolition of buildings, surface structures, 
pipes and cables that are dangerous to human health and safety. All buildings and sur-
face facilities and structures are to be demolished and crushed to pieces of a size of no 
more than 30 cm. Demolishing is usually done using excavators with a grab and picker 
arm or similar grabbing/picking devices.  

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Demolition  debris  may  comprise  scrap  metal  (steel),  plastic,  wood,  pipes,  cables,  or-
ganic  contamination  (oil,  etc.).  Uncontaminated  materials  and  contaminated  materials 
and  wastes  should  be  separated  as  far  as  possible and reasonable applicable, to re-
duce  the  amount  of  wastes  for  disposal.  Scrap  metal  is  cut  into  proper  pieces  for 
transport.  The  contamination  of  steel  and  other  scrap  metal  should  be  measured  in 
order to decide about the disposal procedure. Clean metal may be released while con-
taminated  metals  need  to  be  buried  in  a  disposal  cell.  Contaminated  scrap  metal 
should be cut and disposed in disposal cells which shall be filled with concrete to fix the 
metal.  This  allows  a  safe  and  stable  disposal  and  also  reduces  the  risk  of  looting  by 
scavengers. 

If  needed,  excavation  holes  or  underground  cavities  (cellars,  basements,  bunkers) 
need to be back-filled in order to avoid unacceptable danger to the public as part of the 
following site rehabilitation. Figure 54 illustrates typical mining facilities structures to be 
demolished. 

Figure 54: Typical mining facilities structures to be demolished 

4.6.19  Water Management and Treatment 

The term mine water describes all water that circulates in the mine, comes into contact 
with  the  underground  or  open  pit  host  rocks  or  raw  material.  It  does  not  include  the 
processing water, and it is not necessarily polluted. Water management activities dur-
ing the extraction process include groundwater and mine water management, the op-
eration of water supply and disposal, disposal of liquid processing residues in tailings 
dams  and  mine  flooding  protection  (Schneider  &  Wolkersorfer,  2021).  These  facilities 
must be closed as well. Furthermore, flood protection measures must be planned for all 
mining facilities. 

Usually,  mine  water  with  the  highest  environmental  relevance  is  Acid  Mine  Drainage 
(AMD),  which  is  mine  water  with  a  pH  below  5.6  (Younger  &  Wolkersdorfer,  2004; 
Wolkersdorfer, 2008). It forms when iron (di)-sulphides in the rock are oxidized and not 
enough  buffering  minerals  exist.  The  acidic  environment  in  the  mine  water  provides 
optimal conditions for the solution of metals and metalloids from the surrounding rock. 
As  a  result,  acid  mine  water  is  usually  highly  mineralized  (Younger  &  Wolkersdorfer, 
2004;  Wolkersdorfer,  2008).  If  it  is  not  treated  and  is  not  prevented  from  spreading 

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large  amounts  of  acid  mine  water  can  into  nearby  rivers  or  pollute  the  groundwater. 
Both, the extracted pore water and the supernatant water do usually need treatment.  

Approaches used entail mechanical, chemical, or biological methods or a combination 
of  these  (Johnson  &  Hallberg,  2005;  Trembley  &  Hogan,  2000).  Due  to  the  site  size 
and the lengthy time required for the mine water treatment, the extractive industry often 
employs passive water treatment methods which are based on a combination of aera-
tion and biological treatment (e.g. with microorganisms (Neculita et al. 2007; Gazea et 
al.  1996;  Baker  &  Banfield,  2003,  Kleinmann  et  al.  1981;  Trembley  &  Hogan,  2000; 
Martinez  et  al.  2019).  These  mine  water  treatment  methods  are  designed  to  occur  in 
open  basins  (e.g.,  constructed  wetlands)  and  are  located  at  the  bottom  of  the  mine 
water  outlet  (Younger  &  Wolkersdorfer,  2004;  Wolkersdorfer,  2008).  Further  chemical 
treatment  options  for  metals  include  the  use  of  reactive  materials  (Schneider  et  al. 
2001). 

4.6.20  Ensuring Long Term Geotechnical Stability 

The priority of all closure methods is to ensure geotechnical stability, in particular the 
closure of the tailings ponds, shafts and open-cast mines. Most of these closure meth-
ods  are  combined  with  other  geotechnical  stabilization  methods  as  well  as  geotech-
nical monitoring to ensure long term safety of the site. 

4.6.21  Ensuring Long Term Environmental Safety 

AMD represents a major challenge in mining practice, because 1) it is heavily polluted 
and  2)  there  are  mining  sites  where  it  is  produced  in  large  quantities  (Schneider  & 
Wolkersorfer, 2021). A classic method for treating AMD is liming (i.e., neutralization by 
means  of  calcium  carbonate,  calcium  oxide,  calcium  hydroxide  or  sodium  hydroxide). 
This  method  of  treatment  results  in  potentially  dangerous  residues  that  must  be  dis-
posed of appropriately. 

4.7  Closure of Energy Minerals Mining Sites 

4.7.1  Overview 

Energy minerals mining comprises lignite, hard coal, hydrocarbons and uranium. Ura-
nium ore mining and closure is not separately discussed in this section as uranium in 
terms of material is a metals, and thus operated and closed like metal mines. The clo-
sure technology for uranium mines can be seen from section 4.3. The focus in the pre-
sent  section  is  on  lignite  and  hard  coal  mining  as  well  as  hydrocarbon  extraction,  re-
spectively  their  closure.  The  majority  of  solid  energy  minerals  is  mined  in  open  cast 
mines: lignite and hard coal. The open cast  mine is a substantial impact on nature: a 
huge hole is created, which continues to move as it is mined (figure 55). The resulting 
pit is usually only as large as the so-called deficit, the amount of brown coal that was 
excavated.  The  remaining  holes  are  prepared  accordingly  for  flooding:  Since  a  steep 
front would always break open, the embankments are to be flattened. 

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Figure 55: Open cast lignite mining: in operation (left); in closure through open pit 
flooding (right) 

The  impact  on  the  environment  in open-cast mining is mainly determined by the high 
land use. Further environmental impacts are the lowering of groundwater and the de-
velopment of dust. In civil engineering, the main effects are the mining damage caused 
by subsidence. These consist of damage to buildings in built-up areas and the need to 
mount the flowing water to ensure the flow. Furthermore, areas for heaps and day facil-
ities are used during the operating time of a mine. 

Hard coal mining takes usually place underground. Access to the miners' underground 
workplace  is  through  the  shaft,  like  in  ore  mining.  In  it,  a  conveyor  basket  transports 
people and materials. The individual shafts are connected to each other by routes that 
also allow access to the individual mining areas. The actual mining of hard coal takes 
place  today  with  modern  conveyors  in  the  longwall,  where  the  coal  is  extracted  from 
the seam that is the coal layer that lies between layers of rock. The environmental im-
pact of hard coal mining can be divided into two groups: land use and mining damage. 

4.7.2  Particular Challenges at Energy Minerals Mining Sites 

Most  lignite  mining  sites  that  require  landscape  rehabilitation  are  large  as  open  cast 
mines  consume  huge  regions  of  land  including  the existing land use like settlements. 
The challenge in closing open cast mines of lignite mining are the size, and the needed 
material  volumes.  Another  challenge  is  the  special  planning  particularly  for  the  after-
closure  period.  As  hard  coal  mining  often  takes  place  underground,  the  landscaping 
issues are not that pressing. However, there are challenges in terms of the closure of 
the underground structure that are comparable to re mining sites. Coal mining sites are 
usually decades in operation, and further decades are needed to close them. This situ-
ation causes socio-economic challenges to the regions that must be considered in the 
closure approach. Both, lignite and hard coal mining sites are prone to AMD generation 
and often need mine water treatment. As lignite mining takes place in coarse rocks, it is 
often subject to land subsidence. Hard coal mining mainly takes place underground, so 
stability problems do not happen with a priority like in lignite mining. 

Particular challenges exist also with the other energy minerals mining sites. As uranium 
is  a  radioactive  element,  uranium  mining  requires  particular  radiation  protection 
measures, not only during the operation but during the closure and rehabilitation of the 
site as well. For that reason, a radioactive pollution potential of rock heaps and tailings 
ponds of uranium mining requires particular radiation protection measures in terms of 

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water  and  gas  migration  path.  But  not  only  uranium  mining  can  cause  radiation  haz-
ards.  Also  hydrocarbon  mining,  particularly  oil  exploration  and  production,  often  pro-
duces radioactive residues. These materials are considered as NORM waste and must 
be treated accordingly (Doyi et al. 2016). 

4.7.3  Closure of Open Cast Mines 

Usually, the use of the area for mining has had a substantial effect on the regional wa-
ter balance system, as water regulating vegetation may have been removed and natu-
ral  watersheds  drained.  The  stage  of  mine  closure  and  rehabilitation  provides  an  op-
portunity  to  restore  ecosystems  and  aquifers  (Heikkinen  et  al.  2008;  McHaina,  2001; 
McKenna,  2002;  Slingerland  &  Wilson,  2015;  Sheoran  et  al.  2010),  though  rehabilita-
tion  of  most  mining  sites  requires  decades  of  restoration  work  (Slingerland  &  Wilson, 
2015; Sheoran et al. 2010). For that reason, large scale soil stabilisation activities are 
necessary  before  closure  can  take  place.  Open  pits,  particularly  those  resulting  from 
lignite mining, due to their size and the missing material volume, often will be flooded 
(Best practice). In the frame of mining site rehabilitation, flooding refers to the cut-off of 
the  drainage  systems  in  order  to  allow  the  natural  surface  and  ground  water  to  enter 
the mine (Melchers et al. 2019). Closure of open cast lignite mines means in particular 
to solve the following tasks: 

•  Stable  design  of  the  remaining  embankments  and  provision  for  the  necessary 

load-bearing capacity of the tipping surfaces, 

•  development  of  water  management conditions, that is design and construction 
of  water  transporting  systems  like  water  diversion  channels,  siphon  pipes, 
groundwater pumping systems etc. 

•  Optimization of the water-land distribution in the area to be redeveloped, includ-

ing upgrading of already recultivated areas, 

•  Creation  of  conditions  for  the  assigned  after  use  including  integration  of  the 
post-mining landscape into the surrounding landscape as well as conservation 
of habitats for endangered animal and plant species, 

•  Treatment / disposal of potentially contaminated areas. 

Figure 56 shows the main reclamation steps of open cast energy minerals mining sites 
according to Tudeshki & Pielow (2018). The details of the main steps are explained in 
the following figures. 

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Figure 56: Main reclamation steps steps of open cast energy minerals mining sites ac-
cording to Tudeshki & Pielow (2018), amended and modified by the authors 

Figure 57: Activities in terms of mass movement in open cast lignite mine closure 
(Tudeshki & Pielow, 2018) 

Figure 58: Activities in terms of embankment and soil stabilisation in open cast lignite 
mine closure (Tudeshki & Pielow, 2018; amended by the authors) 

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Lignite mining leaves behind ecotopes that can be described as extreme locations for 
physical  soil,  chemical  and  biotic  reasons.  With  the  design  of  the  post-mining  land-
scape, the prerequisites for diverse and ecologically stable areas of life must be creat-
ed.  The  newly  created  landscape  elements  (e.g.  lakes,  ponds,  shallow  water  areas, 
ditches,  vestibules,  meadows,  fields,  forests  and  forest  fringes)  significantly  improve 
the level of equipment in the redevelopment area. Reclamation takes place on the for-
mer tipping areas, the deposited and compacted waste rock.  

Figure 59: Activities in terms of embankment and soil stabilisation in open cast lignite 
mine closure (Tudeshki & Pielow, 2018; amended by the authors) 

Mine  flooding  is  a  rehabilitation  activity  that  can  take  several  years  or  even  decades. 
Large volumes of water are necessary that would then be unavailable for other purpos-
es during the flooding period (Figure 60). Flooding measures are closely connected to 
other geotechnical measures that are necessary (e.g. the stabilisation of the embank-
ments  of  the  future  lakes).  In  addition,  a  chemical  stabilisation  might  be  required  in 
case AMD is generated during the flooding process (Johnson & Hallberg, 2005). 

Figure 60: Activities in terms of water management measures including open pit land-
scape restoration (Tudeshki & Pielow, 2018; amended by the authors) 

The process of demolishing of mining facilities, processing plants and other operational 
buildings  includes  facilities  and  equipment  in  the  open  cast  mine  as  well  as  facilities 
and infrastructure outside the open pit. 

Figure 61: Activities in terms of repair of mining damage (Tudeshki & Pielow, 2018)

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4.7.4  Closure of Underground Mines 

Technically speaking, the closure of underground mines for energy mineral resources 
is practised like for ore mines, as describes in section 4.3.3. 

4.7.5  Water Management 

In  addition  to  damaging  nature  and  the  landscape,  lignite  open  cast  mining  often  af-
fects both, water quantity and quality in the catchment area (Schneider & Wolkersdor-
fer, 2021). Water resources are subject to competing usage claims as a result of min-
ing activities. Strict control on the amount of water withdrawn for mining should be en-
forced by a water management authority.  

Lignite  extraction  has  had  a  particularly  profound  and  lasting  impact  on  the  region's 
water balance. To extract almost up to 190 million tons of brown coal per year in Lusa-
tia, for example, around 1.2 billion cubic meters of water had to be lifted at the same 
time. As a result, a billions of groundwater deficit had arisen up to 1990, whereby the 
groundwater was partially lowered to a depth of 100 meters. Mine closure is assigned 
to close such deficits. Technical means are groundwater retention, pumping systems, 
vacuum  systems  and  connecting  pipes.  In  case  of  groundwater  leakage,  a  retaining 
wall might be necessary to ensure the groundwater level on a regional scale. Figure 63 
shows a groundwater retention wall and the sealing wall cutter its construction. 

Water  management  during  closure  and  rehabilitation  work  in  lignite  open  cast  mining 
typically requires groundwater retention as well as the construction of water diversion 
channels. This is especially the case when several mines on a mining site are undergo-
ing rehabilitation at the same time, as in the case of the “Lusatian Lakeland” in Germa-
ny. In this area, water was diverted to flood open-cast mines, developing them as lakes 
into a tourist area. The diversion channels used to flood the mines were also used to 
support recreational use of small boats by tourists (Lintz et al. 2012). 

Figure 62 shows common water management practices: the flooding of a former open 
cast lignite mine, the construction of water diversion channels, the construction of wa-
ter level regulation facilities, and mine water management by water keeping through a 
retaining wall. In the direct open-cast mine area, the natural geological structure is irre-
trievably  devastated.  This  might  lead  to  a  "hydraulic  short  circuit",  which  means  that 
pollutants can spread unhindered from previously existing protective separating layers 
to great depths. The drainage of the deep aquifers also creates a new pressure distri-
bution:  If  balanced  pressure  conditions  prevailed  between  the  groundwater  levels  be-
fore the large swamps were set in, a pressure difference now arises. This leads to an 
extensive leakage of the clay horizons from the upper aquifers. 

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Figure 62: Water management  practices: flooding of a former open cast lignite mine 
(above left), construction of water diversion channels (above right), construction of wa-
ter level regulation facilities (down left), mine water management, water is kept through 
a retaining wall (down right) 

On the one hand, this so-called leakage effect in the upper groundwater aquifer reduc-
es the groundwater supply, on the other hand, near-surface groundwater contaminated 
with  other  pollutants  (for  instance  from  agriculture)  can  now  penetrate  into  the  next 
lower  aquifers.  With  the  high  pressure  differences  (greater  than  20  meters)  between 
the aquifers, there are also serious water losses due to infiltration into deeper ground-
water  levels.  Leakage  can  be  avoided  through  sealing  with  a  groundwater  retention 
wall (figure 63). Further, the lowering of the groundwater level in the built-up areas will 
be necessary if the buildings shall not be removed from the revitalisation area. This can 
only be achieved by continuing the groundwater management on the long term. 

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Figure 63: Water management practices: groundwater retention wall (left); sealing wall 
cutter for construction of a groundwater retention wall (right) 

Figure 64: Water management practices: groundwater management (left); cascade 
outflow of siphon pipe for water level controlling (right) 

A groundwater quality deterioration results often from the overburden dumps. With the 
destruction  of  the  natural  layer  sequence  by  the  open-cast  mine,  sulphides  bound  in 
the soil reach the surface. If these easily releasable sulphur compounds react with ox-
ygen  and  if  the  tip  of  the  waste  heap  body  is  flooded  with  rising  groundwater,  a  con-
stant  stream  of  pollutants  flows  into  the  underground.  Various  measures  were  exam-
ined to minimize the discharge of material from the inner tip. These range from "tipping 
management", i.e tipping of the acid-sensitive masses, preferably with the exclusion of 
oxygen, to the addition of power plant ash and lime as an acid buffer. Ultimately, these 
measures  could  only  reduce  pyrite  weathering  by  around  four  percent  in  absolute 
terms. A relative minimization of the acidification of the groundwater by a maximum of 
one  third  can  be  achieved,  which  means  that  two  thirds  of  the  acidification  potential 
remains. 

Water management and ecological problems after the open pit closure do not only re-
sult  from  acidification.  There  might  be  also  problem  resulting  from  deposited  power 

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plant  ash  containing  concentrated  heavy  metals.  There  is  therefore  a  risk  that  these 
pollutants  will  be  released  as  the  groundwater  slowly  rises  again.  Therefore,  water 
treatment might be necessary. Water treatment methods may comprise flooding water 
management,  mine  water  treatment  by  active  or  passive  treatment  methods,  inlake 
treatment  (liming  of  the  flooding  lake),  groundwater  treatment  by  active  or  passive 
treatment methods and/or a conditioning of the waste rock tipping. Respective method-
ologies  are  provided  in  the  MWEI  BREF,  and  comprise  pump  and  treat  (if  necessary 
biologically  supported),  that  means  active  groundwater  treatment,  or  reactive  walls  / 
funnel and gate, that means passive treatment. Active and passive treatment method-
ologies  might  be  also  applied  for  polluted  surface  water.  The  respective  treatment 
methods are conventional waste water treatment, preferably through active carbon, or 
passive  treatment  through  biologically  activated  wetlands  or  Reducing  and  Alkalinity 
Producing  Systems  (RAPS/SAPS),  that  might  be  designed  as  open  limestone  cas-
cades (Trembley & Hogan, 2000).  

4.7.6  Ensuring Long Term Geotechnical Stability 

With coal extraction, a large amount of waste is extracted and tipped, starting from the 
heap  and  later  into  the  carburized  hollow  form  of  the  open-cast  mine.  The  extraction 
and transport technology of the clearing masses has a decisive influence on their soil 
physical properties. Depending on the technologies used, overburden conveyor tipping, 
skip tipping and in some cases directly tilted masses are created (Geß, 2009). With the 
individual  technologies,  differently  mixed  soils  are  created,  which  differ  according  to 
their geological origin in the cinderial ratio.  

The main difference between the tipping floors and the grown mountains is their loose 
storage and the associated high deformation potential. The deformation is determined 
by grain composition and water content of the soil (Geß, 2009). Different deformation 
potentials  occur  in  the  individual  tipping  areas,  which  are  subdivided  into  self-settling 
(by compressibility of the loosely poured debris), sagging (occur due to the rise or fluc-
tuations  in  groundwater  in  the  waste  rock  heap  or  through  seepage  and  infiltration  of 
precipitation), and loading (caused by the weight of a building). The deformation behav-
iour of the tipper dumps is influenced by the position to the edges of the tipper. A dis-
tinction  is  made  between  open  pit  embankment  areas  with  the  technologically  deter-
mined edge hoses, inner tipping areas, tipping edge areas and tipping embankments. 
The embankment and edge areas are particularly critical here, since considerable set-
tlement differences can occur at short distances (Geß, 2009). 

A wide variety of methods can be used to control the effects of the high settlement and 
movement  potential  on  lignite  dumps,  which  differ  in  their  mode  of  action.  These  in-
clude  methods  for  increasing  the  rigidity  of  the  floors,  reducing  subsidence  through 
stress  redistribution  or  technical  solutions  on  the  planned  building  and  foundation 
(Geß, 2009). The following methods can be used to increase stability: preloading, verti-
cal drainage under preload in water saturated areas, material exchange, embankment 
stabilisation  through  compaction  (vibro  compaction,  dynamic  intensive  compaction, 
explosive compaction, falling weight compaction), and solidification injections. 

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Methods to ensure stress redistribution are geogrids and tensile geotextiles, reinforce-
ments  or  improved  floor  plates.  Figure  65  illustrates  technical  solutions  to  ensure  ge-
otechnical stability in lignite mine closure. 

Figure 65: Ensuring geotechnical stability in lignite mine closure: slope stabilisation of 
former open cast that is under flooding (above left), profiling of slopes (above right); 
stabilisation of underground instability of coarse rock through injection (down left), vibro 
compaction for ensuring ground stability (down right) 

Further, bioengineering approaches are applied for erosion protection and stabilisation 
of embankments. Bioengineering methods are an effective method of sustainable and 
nature-near hydraulic engineering. They have their origin in protective water engineer-
ing and are used as handicraft techniques for securing water banks and embankments. 
In mine closure, for example, live fascines on bush layers, spreaders with live fascines 
for  embankment  protection  as  foot  protection,  and  live  fascines  in  combination  with 
protection mats made of natural fibre fabric can be used. Important is also to ensure a 
long  term  stable  vegetation  on  long  term  stable  embankments.  Bioengineering  is  a 
method to use biological methods to a) ensure geotechnical stabilization and b) green-
ing through ecologically stable vegetation that ensures further a sound water balance 
as well as an ecological balance that is in line with the ecological setting of the region. 
Figure 66 illustrates ecological engineering stabilisation and erosion protection for wa-

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ter related structures, figure 67 for earth structures. Feasible types of live stakes are for 
instance Black Willow (Salix nigra), Silky Dogwood (Cornus amomum), Interior Willow 
(Salix longifolia), Pussy Willow (Salix discolor), Streamco Willow (Salix coltetti), Arrow-
wood (Viburnum dentatum), Buttonbush (Cephalanthus occidentalis). 

Figure 66: Ensuring geotechnical stability in lignite mine closure: bioengineering stabili-
sation and erosion protection for water related structures, here: spreaders with live fas-
cines for embankment protection (left); use of water engineering rocks from natural 
material combined with live stakes for stabilisation and greening (right) 

Figure 67: Ensuring geotechnical stability in lignite mine closure: bioengineering stabili-
sation and erosion protection for earth structures, here: Living branches of Salix are 
arranged as fascines for slope stabilisation with drainage function. 

If the areas for forestry were left to their own devices, a distinction must be made as to 
whether there are tertiary acid soils or pleistocene soils. A colonization of tertiary soils 
by  plants  can  take  many  decades  due  to  the  sometimes  extremely  low  pH  values.  If 
forest areas are to be established, these soils must be thoroughly limed beforehand, in 
particular to ensure the ecological stability of the stands. Mining areas to be closed can 
also  be  left  to  natural  succession.  Figures  68  and  69  illustrate  bioengineering 
measures for ensuring geotechnical stability in lignite mine closure, particularly for sta-
bilisation  and  erosion  protection  of  embankments.  Bioengineering  methods  are  very 
effective in open cast lignite mining closure as the areas are that huge and convention-
al technological methodologies are very costly. Planting of trees will further contribute 
to the long term stability. Suitable plants that are naturally occurring in the rehabilitation 
region  support  the  reclamation  process.  To  select  feasible  plants  information  on  the 

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naturally  occurring  vegetation  should  be  collected.  Preferably  local  seeding  material 
should be used as this seeding material is adapted to the local climate. 

Figure 68: Ensuring geotechnical stability through ecological engineering (Dittrich & 
Stowasser, 2010) 

Figure 68 provides a schematic diagram of willow spreader layer with pruning trees as 
slope protection (left): (1)  soil placed back, (2) trench below the low level water line, (3) 
wooden sticks for stabilization of the spreader layer, (4) expansive willow branches, (5) 
transom  for  fastening  the  willow  branches  on  the  embankment,  (6)  over-grounding  of 
the willow tree (max. 2 to 3 cm), (7) embankment foot protection by two layers of prun-
ing trees. Schematic diagram of bush layer with pruning trees as foot protection (right): 
(1)  pilot  pole,  (2)  first  layer  of  pruning  trees,  (3)  pliers  for  fastening  the  first  layer  of 
pruning trees, (4) second layer of pruning trees, (5+ 6) viable pastures for fastening the 
second Location of pruning trees, (7) bush location for rooting the poured earth. 

Figure 69: Ecological engineering stabilisation and erosion protection of opencast lig-
nite mining, here: slopes of flooded mine (left); planting of trees for reclamation and 
erosion protection purposes (right) 

4.7.7  Ensuring Long Term Environmental Safety 

The main thread to long term environmental safety in lignite mining closure is acidifica-
tion. Rehabilitation of AMD forms a challenge due to the large volumes, several types 
of  origin  of  acidification,  as  well  as  the  different  flow  paths  to  arrive  in  the  open  cast 
mine  (table  9).  Depending  on  the  geological  setting  must  be  designed  the  closure 
strategy,  that  may  include  retention  walls,  water  diversion  channels  (in  combination 
with RAPS if applicable), as well as groundwater extraction well galleries. Often a sub-

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sequent AMD treatment is needed that might comprise inlake liming, geochemical bar-
riers or water extraction. Up to now doesn’t exist a feasible solution for a circular use of 
AMD. 

Table 9: Typing of acidic open-cast ponds according to the origin of the acidification 
(Nixdorf et al., 2000) 

Type of open cast mine acidification 

Origin  of  acidi-
fication 

Dominating 
cess 

pro-

autochthone 

Exfiltration  of  pore 
water  from  the  de-
posited overburden 

autochthone 

Leaching  of 
the 
slopes  of  the  de-
posited overburden 

allochthone 

Overflow  of  pore 
water  from  the  de-
posited  overburden 
from  neighbouring 
open cast mines 

allochthone 

Overflow  of  water 
from  the  neighbour-
ing open cast mines 

4.7.8  Closure of Hydrocarbon Boreholes 

Oil and gas are explored and extracted through boreholes / drilling (figure 70). Up to a 
vertical  depth  of  5,000  m,  a  usable  diameter  of  450  mm  can  be  achieved  in  a  cased 
borehole using standard drilling methods. If the resource is located at a smaller depth, 
a  larger  diameter  can  be  achieved  with  the  technology  used  today,  e.g.  at  2,000  m 
depth, this is approx. 650 mm. In the past, larger diameters have been realized in sci-
entific and military drilling projects. A standard bore with a diameter of 375 mm and a 
depth of 5,000 m arrives to a cost of approx. € 30 million (pure drilling costs as of the 
end of 2015). The costs increase disproportionately with the diameter. The equipment 
for the operation of an oil or gas drilling is shown in figure 70. There are different types 
of host rocks for hydrocarbon deposits. Often they occur in salt host hock. 

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Figure 70: Principle of exploration and extraction: Oil well with pumpjack scheme (left. 
legend: 1. driving motor 2. counterweight 3. connecting rod 4. balancer 5. horse head 
6. piston rod 7. Seal as part of the eruption cross 8. Pipe 9. concrete filling of the bore-
hole 10. outer borehole piping 11. pump rod 12. inner borehole piping 13. deep pump 
14. pump valves 15. oil-bearing rock layer). Principle of oil and gas exploration using 
intelligent drilling (right, figure source: Bohrtechnik © 2018 BVEG - Bundesverband 
Erdgas, Erdöl und Geoenergie e.V). 

Closure of oil and gas boreholes 

The  main  closure  technique  is  filling.  In  principle,  the  following  principles  can  be  as-
sumed: 

•  Extraction boreholes shall be filled in such a way that burglaries on the surface 
of the earth are avoided and subsequent use of the subsurface for the extrac-
tion of mineral resources and water or for deep storage is not impaired. 

•  Filling must be carried out in such a way that, based on all experience, a liquid- 
and  gas-tight  seal  is  achieved  and  adverse  changes  in  the  groundwater  are 
avoided. 

•  The borehole must be filled completely. The areas of usable oil, natural gas and 
salt  deposits,  of  usable  storage  and  water  horizons  as  well  as  of  pressurized 
horizons with inflows (collectively referred to in this guideline as deposit), liners, 
interfaces  of  pipes,  pipes  and  annular  spaces  as  well  as  the  pipe  shoe  of  the 
deepest pipe tour, further partially uncased borehole as well as the area below 
the earth surface are to be sealed by special filling lines. 

• 

In areas where difficulties have arisen during drilling or conveying, special filling 
sections  may  also  be  required.  The  special  filling  sections  must  be  filled  with 
suitable  cement  or  other  suitable  solids,  if  necessary  in  connection  with  me-
chanical  seals.  Appropriate  measures  must  be  taken  to  ensure  that  the  solids 
adhere well to the pipe or borehole wall. 

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•  The materials used for filling the drilling or related lines shall not be aggressive 

to the host rock, the piping or the materials of the special filling lines. 

•  Special  filling  levels  should  range  from  50  m  below  to  50  m  above  the  aban-
doned  deposit.  This  can  be  done  using  pressure  cementation  or  mechanical 
sealing. 

There is no need for a continuous fill route within large dimension salt layers. At least in 
the hanging and lying areas, special filling sections of at least 100 m in length in salt 
and 50 m in bedrock must be introduced. The borehole is to be filled with a special fill 
line from the surface of the earth to a depth of 100 m. 

In  the  case  of  borehole  closure,  after  the  effectiveness  of  each  closure  mechanism 
(cement plug, salt, mechanical barriers) in the area above it should be monitored - be-
fore the next closure is implemented. In case of occurrence of NORM waste material, 
that material must be disposed of in a feasible disposal site (Doyi et al. 2016). The ma-
terial  might  be  treated,  however  in  such  a  case  the  radioactive  material  must  be  dis-
posed  of  separately.  For  the  rest  of  the  dismantling  activities  (e.g.  demolition  of  pro-
cessing facilities) apply the closure provisions provided in the sections above. 

4.8  Closure of Industrial Minerals Mining Sites 

4.8.1  Overview 

industrial  minerals  are  any  rock,  mineral,  or  other  naturally  occurring  material  of  eco-
nomic  value,  excluding  metals  and  energy  minerals.  Typically,  they  are  large  volume 
with low value commodities. They are extracted from surface and underground mines 
like  the  other  resources  that  have  been  already  discussed.  Industrial  minerals  are  of 
several  genetic  types,  and  of  several  structural  characteristics.  The  main  types  of  in-
dustrial minerals are: 

•  Metallurgical additives: limestone, barite, fluorspar 

•  Mineral  chemical  raw  materials:  fluorspar,  limestone,  boron,  barite,  gypsum, 

talc,  

•  Agrochemical raw materials: salt rocks / potash, phosphates 

•  Raw materials for glass production: glass sand, feldspar, limestone 

•  Raw materials for ceramics: kaolin, feldspar 

• 

Isolation  materials:  chromite,  magnesite,  sillimanite,  asbestos  (asbestos  is  not 
anymore permitted for industrial applications in the EU) 

•  Decorative and precious stones: diamond, ruby, emerald etc. 

For the majority of the mentioned materials apply the closure methodologies described 
before  in  aggregates,  ore  or  energy  minerals  mining,  depending  on  their  properties 
(solid rock, coarse rocks). Comparable closure techniques apply: 

•  Like  aggregate  mining,  solid  rocks:  limestone,  barite,  fluorspar,  gypsum,  feld-

spar, chromite, magnesite (in case of open cast mining) 

•  Like  aggregate  mining,  coarse  rocks:  glass  sand,  kaolin  (in  case  of  open  cast 

mining) 

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•  Like ore mining, solid rock: limestone, barite, fluorspar, bauxite (in case of open 

cast mining) 

For a minority of the industrial minerals are needed chemicals for the processing (see 
4.6.2).  Some  of  them  have  special  properties that require special closure techniques. 
These are particularly salt rocks / potash and phosphates. In this section is focused on 
these materials in order to consider their particular properties in terms of closure. Salt 
rocks / potash are usually explored and extracted underground or through deep drilling 
to dissolve the brine. However, due to their chemical properties, particular closure as-
pects  must  be  respected.  Phosphates  do  also  have  special  properties,  and  after  pro-
cessing  to  obtain  some  types  of  raw  materials  result  tailings  ponds  (so  called  phos-
phogypsum  ponds,  figure  70)  that  have  comparable  properties  to  ore  mining  tailings 
ponds. Further, phosphogypsum ponds often contain metals or radionuclides as resid-
ual by-products of the phosphorous ore processing  (Papaslioti  et al. 2018). The main 
challenges in the closure process of industrial minerals are  

•  underground  cavities  with  corresponding  effects  on  the  surface  (underground 

mining); 

•  open or flooded shafts (underground mining); 

•  only limited usable areas in the vicinity of the shaft systems (underground min-

ing); 

•  Enclosed space mostly not or only partially usable industrial buildings; 

• 

large  residue  dumps,  e.g.  with  piled-up  salts  and  the  dissolved  salts  that  flow 
out of them, which transport a substantial salt load into the receiving rivers. 

Several of the industrials minerals are not inert, that means chemically relevant during 
closure. 

Figure 71: Sample of phosphogypsum ponds in Andalusia, Spain 

4.8.2  Particular Challenges at Industrial Minerals Mining Sites 

Table 10 gives an overview on inorganic reagents and their primary functions in indus-
trial mineral processing (Pearse, 2005). Those materials may be found in the sedimen-
tation ponds, depending on the mineral processing methodology. 

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Table 10: Some inorganic reagents and their primary functions in industrial mineral 
processing (Pearse, 2005) 

Reagent 

Sodium silicate 

Primary function 

Slimes dispersant 

Sodium fluorosilicate 

Fluorite and silicate depressant 

Sodium hydrosulphide 

Sulphidizer for oxide and weathered minerals 

Sulphuric acid 

Fatty  acid  collector  removal  in  phosphate  flo-
tation 

Alum,  Polyaluminium  chloride,  Ferric 
chloride 

Clarification 

Zinc dithionite 

Bleaching agent 

Other challenges result from salt / potash mining and phosphates, as these sites might 
typically  have  a  large  dimension.  Further,  salt  and  potash  minerals  are highly soluble 
resulting in a quite fast material transport into the environment. Salt and potash miner-
als in higher concentration are toxic to several aquatic animals. 

4.8.3  Earthworks 

The  main  earth  works  are  profiling  and  stabilising  works.  During  the  closure  works  is 
necessary to ensure erosion prevention, preferably through establishment of vegetation 
on a stable landform. Earthworks for industrial mineral mine closure are comparable to 
those described in 4.3.4. 

4.8.4  Water Management 

Applicable  water  management  activities  depend  on  the  type  of  industrial  mineral  and 
the  processing  technology  that  means  if  additional  chemicals  are  used  in  the  further 
processing. Thus, as water management approaches depend on the resource proper-
ties and the type of mining, they are comparable to aggregates (see section 4.3.1) and 
ore  mining  (see  section  4.3.2).  In  case  of  chemicals  use,  water  treatment  is  usually 
necessary.  

Salt / potash mining requires a special water management strategy as the resource is 
highly soluble and can lead to salt intrusion in surface and groundwater. In case of salt 
leaching and brine extraction, highly concentrated salty solutions (brines) are generat-
ed that can be pumped up to the surface. However, the mineral solutions are typically 
also corrosive to the host rock and form caverns that can be hardly stopped to further 
dissolve  salt.  Brines  can  create  huge  caverns  that  deep  drilling  to  dissolve  the  brine. 
Figure  72  shows  brine  caused  caverns  and  their  geotechnical  impacts  (Warren, 
2016a).  

In contrast to other mining branches the prevention of water inflow into the abandoned 
potash or salt mine is also required during the post-operational phase to prevent haz-
ards to the surface above the mines and to guarantee safe ground. Water-tight shaft or 
drift sealing, therefore, is one focus of mine closure in mineral salt mines. 

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Figure 72: Brine caused caverns and their geotechnical impacts (Warren, 2016a).  

4.8.5  Ensuring Long Term Geotechnical Stability 

A  breached  cavern  with  a  weak  roof  can  likely  lead  to  a  collapse  (figure  72,  Warren, 
2016a).  Geotechnical stabilisation methods focus on hydraulic filling of caverns or oth-
er  mine  workings.  Salt  usually  seals,  but  sometimes  leaks  (Warren,  2016a).  To  mini-
mize subsidence, to avoid rock bursts and to maximize mineral extraction, special hy-
draulic  fill  is  used  in  potash  and  salt  mining  (e.g.  Fliß  et  al.  2011).  Filling  of  salt  and 
potash  mines  may  take  place  during  underground  extraction  or  after  production  shut-
down. Figure 73 illustrates the hydraulic filling process of filling long chambers.  

Figure 73: Principle sketch of hydraulic filling in potash mining industry  
(Fliß et al. 2011) 

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Caverns can be filled in a similar way, and in a second step the remaining pillars can 
be excavated, so that the fill acts as stabilizing material (Fliß et al. 2011). In potash and 
salt special attention has to be paid to the fluids to minimize dissolution processes (e.g. 
drainage, water management, chemical composition, use of saturated brines etc.). Hy-
draulic fill with high content of rock salt with MgCl2 brine leads to a long-term stable fill 
(Fliß  et  al.  2011).  Crushed  salt  is  the  most  used  fill  material  in  salt  mines.  Long-term 
stable  fill  for  potash  mines  with  MgCl  brines  is  the  so-called  Sorel-concrete  or  MgO-
concrete,  based  on  Mg-Si-hydrates  (Walling  &  Provis,  2016).  Figure 73 illustrates the 
principle of hydraulic filling in potash mining industry (Fliß et al. 2011). Figure 74 shows 
concepts for shaft stabilisation in potash mines (Zschiedrich et al. 2017). 

Figure 74: Concepts for shaft stabilisation in potash mining (Zschiedrich et al. 2017) 

4.8.6  Ensuring Long Term Environmental Safety 

Salt  mining  leads  to  the  release  of  saline  solutions.  The  EU  Water  Protection  Laws 
require that salinization of the continent's rivers be greatly reduced. This is a challenge, 
particularly in low level water situations, which can lead to a discharge stop. Thus, clo-
sure  measures  need  to  take  into  account  appropriate  dewatering  systems,  with 
groundwater  protection  measures  if  applicable.  Fish,  macrozoobenthos  and  phyto-
plankton are particularly vulnerable to high salt concentrations. Further, high salt con-
centrations are highly aggressive to concrete structures. Thus, all closure piping must 
be done through plastic pipes.  

The closure of mine waste heaps requires a particular attention. The main measure for 
ensuring long term environmental safety of salt and potash mine waste heaps are sur-
face covers that serve further the long term landscaping. Figure 75 shows the system-
atics  of  surface  sealing  /  covering  at  salt  and  potash  dumps  (Palm  &  Kockx,  2018). 
Some of the mine waste heaps are needed to be profiled or flattened in order to ensure 
geotechnical stability. Depending on the surface permeability of the waste heap sites, 

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cover systems might be needed (Palm & Kockx, 2018). The main scope of cover sys-
tems  is  to  reduce  the  salt  or  potash  mobility  and  to  avoid  precipitation  infiltration  into 
the  mine  waste  heap  and  to  ensure  surface  greening.  Also  capillary-breaking  layers 
might  be  applied.  Figure  76  shows  a  stabilisation  concept  for  potash  mining  waste 
heaps (Zschiedrich et al. 2017). 

Figure 75: Systematics of surface sealing / covering at salt and potash mining waste 
heaps (Palm & Kockx, 2018) 

Figure 76: Concept for surface cover of potash mining waste heaps (Zschiedrich et al. 
2017)  

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4.9  Mine Closure Show Cases 

4.9.1  Aggregates Mining 

The aspects of operation and closure strategies and related closure cost in aggregates 
mining are illustrated at the limestone company Ostrauer Kalkwerke GmbH in Germa-
ny.  As  already  mentioned,  aggregates  mining  usually  does  not  produce  hazardous 
substances.  Typically,  the  only  hazardous  substances  that  are  used  in  the  operation 
process  are  explosives.  It  is  necessary  to  underline  that  aggregates  mines  that  are 
operated  according  to  Best  Practice  are  in  a  permanent  and  continuous  process  of 
operation and parallel closure of exhausted rock zones.  The operation and closure of 
gravel  and  sand  opencast  mines  usually  includes  locations  with  average  annual  pro-
duction  volumes  with  lifetimes  of  more  than  40  up  to  about  80  years.  The  limestone 
plant Ostrau with an average annual output of 250.000 to 300.000 tons is a typical ex-
ample. 

Since the extraction takes place in the open-cast mine and the geology of the deposit 
ensures  the  greatest  possible  lossless  mining,  all  residual  materials  (overburden,  se-
lectively obtained particular soil layers) are returned as filling to the exposed areas. The 
filling takes place in such a way that the former mining areas are prepared without any 
further reclamation effort for a future after-use either for forestry or agriculture.  

Interim soil storage 

Reclamation areas 

Figure 77: Aerial view of Ostrauer Kalkwerke GmbH 

Any  topsoil  that  arises  when  the  future  extraction  areas  are  excavated  is  either  re-
installed  as  a  covering  layer  or  sold.  This  means  that  the  operating  result  is  not  bur-

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dened due to additional provision costs and, in addition to environmentally friendly re-
source extraction, the final product is less financially burdened. 

The extracted resource is dolomite limestone that is mined through stroke construction 
methodology.  The  extraction  is  conducted  through  drilling  and  blasting  technology, 
while the loading technology takes place through LHD technology and large tipper. The 
company works very efficient: until the resource processing, there is already an extrac-
tion efficiency of approx. 90%, means very small resource losses. The main products 
are fertilizer, filling materials, and road construction material.  

Geologically, selective extraction with regard to different rock qualities is required. The 
operation is managed according to basic economic aspects in the form of an operating 
point settlement (cost centres) and an annual profit and loss account. The company is 
under  the  supervision  of  the  mining  authority,  i.e.  work  is  carried  out  consistently  ac-
cording to the submitted and confirmed operating plans. Due to the continuous use of 
the overburden for reclamation  means that no provisions are required for subsequent 
reclamation. 

Figure 78: Extraction scheme and further SEE direction of excavation (left); preliminary 
exploration with subsequent extraction (right) 

The waste resource ratio at Ostrauer Kalkwerke GmbH is 2: 1 (i.e. 2 tons of overbur-
den must be managed in advance for the extraction of 1 ton of  limestone). The open 
cast mine is filled during ongoing operations leading to the situation that the recovered 
land  is  usable  again  immediately  after  closure.  Some  seeding  and  greening  cost  and 
some  subsequent  monitoring  cost  might  be  required  up  to  five  years  after  closure. 
However,  due  to  the  application  of  state-of-the-art  technologies  and  Best  Practices 
during  operation,  the  costs  for  reclamation  purposes  are  therefore  minimal  (less  than 
10.000 € per year). 

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4.9.2  Ore Mining 

The show case for ore mining comprises a polymetallic ore including uranium ore min-
ing from Bulgaria. Uranium mining is a special case as it belongs to the energy mine- 
rals; however, it is also an ore and extracted using ore mining technologies. 

Polymetallic ore including uranium ore mining 

The  show  case  illustrates  the  “Remediation  Programme  for  the  Uranium  Mines  in 
Southern  Bulgaria”  (financed  through  EuropeAid/113349/D/SV/BG)  that  was  conduc- 
ted  in  the  period  2004  to  2005.  It  was  financed  by  the  Ministry  of  Regional  Develop-
ment, Republic of Bulgaria, using funds of the European Commission. Background of 
the  project  is  the  Buhovo  ore  deposit  where  past  ore  exploration  was  performed  with 
different  methodologies  (Gitzinger  et.  al.  2011).  As  a  result  of  these  explorations,  39 
ore deposits were identified and developed on the territory of Bulgaria (Gitzinger et. al. 
2011). The show case presents the closure of shafts and adits under different geologi-
cal conditions. An overview on location of the shaft and adit system is given  in figure 
79. 

Figure 79: Overview on the location and the shaft and adit system to be closed 

The main ore deposits for underground extraction are: Buhovo near Sofia, Eleshnitsa, 
Senokos and Simitli in South-West Bulgaria, Vinishte and Smolyanovtsi in North-West 
Bulgaria,  Sliven  in  Central  Bulgaria,  Smolyan,  Dospat  and  Selishte  in  the  Rhodope 
Mountains. Deposits exploited via classical mining methods have a complex geological 
structure  and  are  situated  mainly  in  mountain  regions  (Stara  Planina,  Rhodope  mas-
sive,  East  Sredna  Gora).  The  mean  surface  of  the  ore  beds  is  between  250  m²  and 
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20.000 m², occurring at a depth of about 500 m and a low metal concentration. Under 
favourable conditions of the ore beds, the ISL method (In Situ Leaching) was applied 
(Gitzinger et. al. 2011). Beside radionuclides, other by-products resulting from uranium 
ore production and processing may be detected (Gitzinger et. al. 2011). These are sul-
phates (SO4), carbonates (CO3) and bicarbonates, nitrites, organic solvents and other 
reagents stemming from the uranium extraction and processing as well as metals (Fe, 
Mn, Cu, Zn, Co, Ni, Cr, As, Hg, etc.) from poly-metallic and sulphide-poly-metallic min-
eralisation  accompanying  the  uranium  ores  (Gitzinger  et.  al.  2011).  The  description 
below illustrates the closure approach. 

Shafts in the non-stable rocks of the Eleshnitsa, Dospat and Simitli regions 

The safekeeping measures that had been taken in the past by the closure of the former 
uranium-tungsten ore shafts in the Eleshnitsa, Dospat and Simitli regions were proven 
to be not feasible as the shafts were leaking. The former closure method was filling of 
the shaft with coarse materials and covering the entrance to the shaft with a concrete 
slab. There had been observed geotechnical damage in the filled shafts constantly that 
was attributed to the leakage of the coarse masses. So, the shafts were closed again 
according to state of the art and best practice. The state of the art is to fill shafts in the 
non-stable rocks before the start of flooding along their entire depths from the sump up 
to  surface  with  hydraulically  hardening  and  non-washable  material  with  a  minimum 
compressive  strength  of  2  N/mm².    Shafts  whose  entrances  are  only  covered  with  a 
concrete slab are to be classified as temporarily (provisionally) closed. Since the exist-
ing  situation  could  only  be  changed  with  unreasonably  high  technical  and  economic 
expenditure, the securing measures for these shafts are essentially limited to a dimen-
sionally and quality-appropriate execution of a sealing construction at surface. For the 
shafts whose entrance were only covered with a concrete slab, measures were taken 
to  ensure  the  long-term  safekeeping  of  the  shaft  pipe  under  the  given  conditions. 
Framework projects were developed for the different geotechnical and geological con-
ditions  at  the  locations,  which  were designed in such a way that they could easily be 
transferred to other locations as pilot projects.  

Summarized the following framework projects were realized: 

Securing the existing entries by means of stable ballast barriers, further filling also by 
means of gravel sections, remaining filling up to the surface using cohesive filling col-
umn made of lean concrete. 

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Figure 80: Overview on the location and the shaft and adit system to be closed 

According to the state of the art, partial closure methods can be used for shafts in the 
continuously stable rock, such as: 

• 

• 

• 

Installation of a massive reinforced concrete seal in the onset close to the sur-
face, residual filling with gravel up to surface 

Installation  of  a  concrete  shear  plug  in  the  shaft  area  close  to the surface, re-
sidual filling with gravel up to surface 

Installation of a cohesive filling column section made of hydraulically hardening 
material with a minimum compressive strength of 5 N/mm²), residual filling with 
hydraulic hardening material with a minimum compressive strength of 2 N/mm² 
up to the surface 

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Figure 81: Ensuring geotechnical stability in underground ore mine closure: complete 
filling of the shafts. The section above the flooding level to be expected in the future 
must be installed as a drainage layer before the cohesive filling column reaching to the 
surface layer (left); partial filling (right) 

The installation of a shear plug requires a detailed geotechnical and geological surveys 
of the sites. These sections may need to be re-injected. 

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Figure 82: Break out of shaft, preparation for plugging 

Measures for provision of public safety in the area of abandoned adits in the Eleshnitsa 
and Senekos regions  

According to best practice, the following method for the closure of entrances of aban-
doned adits was applied:  

•  Walling the immediate entrance area 

• 

relocation of a circa 10m long section in the entrance area 

•  Closure of the entrance by blasting. 

If surface breaks occurred in the course of the route, the relevant adit areas were shift-
ed as soon as possible free of voids. A common method is the installation of cemented 
hydraulic fill by drillings. The rehabilitation objects located in the Eleshnitza and Sele-
kos regions can be classified into the following categories according to the initial situa-
tion (figure 83): 

•  Adit open, no water discharge 

•  Adit open, water discharge 

•  Adit open, no water discharge, surface breaks in the route 

•  Adit broken or filled up, water discharge. 

The shafts were closed according to the methodology described in section 4.5. 

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Figure 83: Adit open, no water discharge (left); adit open, water discharge (right) 

Closure cost 

The closure costs were calculated separately for each shaft and adit. Cost for the long 
term stable closure of the entrances (shafts and adits) added up to around 1.2 mill eu-
ros. The costs for each shaft depend on the type of provided custody works, the shaft 
depth and the requirements of the responsible supervisory authorities. The compilation 
is shown in the following tables. 

Table 11: Sample of cost calculation - shafts and adits in Elesnitsa region (in EUR) 

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4.9.3  Energy Minerals Mining 

The aspects of operation and closure strategies and related closure cost of lignite min-
ing  are  illustrated  with  an  abstract  from  the  study  “Assessment  of  Rehabilitation 
Measures  in  East  German  Lignite  Mining”  (Tudeshki  &  Pielow,  2018)  as  this  recent 
publication  illustrates  the  challenges  related  to  stepwise  financial  provisions  and  the 
dimensions of lignite mine closure. This show case refers to a number of lignite mines 
to be closed in Eastern Germany, the measures for the provision of reuse options and 
the related costing. The study was supported by the Regional Agency for Mining, Geol-
ogy and Raw Materials Brandenburg, the competent authority for the mine closure pro-
ject.  Even the project documentation doesn’t contain absolute closure cost, but abso-
lute closure cost, it is an interesting show case for the FG calculation methodology and 
regularly update. Scope of the study was an assessment whether the applied practice 
corresponds to the legal requirements and can be regarded as technically, economical-
ly and legally "practicable".  Following steps were taken: 

•  Systematic analysis of data from Lausitz Energie Bergbau AG 

•  Validation  of  data  with  regard  to  its  technical  content  and  their  assignment  to 

one another 

•  Detailed  plausibility  verification  of  the  structure  and  the  assignment  of  the 

measures to the respective focal points of the reusability 

•  Validation of the methodology for the creation of financial provisions 

•  Checking the quantity framework of each individual measure of reusability and 

the associated unit prices 

•  Checking  the  cash  flows  by  evaluating  the  existing  and  already  created  provi-

sions with regard to their adequacy and adequacy 

•  examination  of  the  development  of  mining  and  tipping  as  a  guideline  for  the 

cash flows. 

On  the  basis  of  the  verified  BoQ  frameworks  and  unit  prices,  taking  into  account  the 
factors  that  have  an  effect  on  financial  mathematics,  calculations  of  the  cash  flows 
were made and the net present value of the relevant measures was calculated. This is 
the  precondition  to  ensure  that  the  financial  provisions  can  be  reliably  checked  and 
assessed.  The  assessment  subject  is  mining-related  financial  provisions  of  Lausitz 
Energie Bergbau AG as of December 31, 2016, which are related to the operating units 
listed below: 

1. Jänschwalde open cast mine 

2. Welzow-Süd open cast mine 

3. Nochten open cast mine 

3.1. Hermannsdorfer See 

3.2. Landscape structure Spreyer Höhe 

4. Reichwalde open cast mine 

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5. Cottbus-Nord open cast mine 

6. Industrial landfills 

6.1. Landfill Jänschwalde I 

6.2. Landfill Jänschwalde II 

7. Central railway operation area 

8. Black Pump industrial site 

8.1. Technical services area 

8.2. Refinement area 

9. Head quarter mining. 

The  total  of  closure  measures  comprises  332  measure  types  with  528  closure  activi-
ties.  The  total  closure  costs  add  up  to  1.38  billion  euros.  Following  types  of  closure 
measures were designed: mass movement, landscaping and reclamation, geotechnical 
stabilisation of waste rock heap sites and embankments, water management measures 
including  open  pit  landscape  restoration,  demolishing  of  mining  facilities,  processing 
plants and other operational buildings, redeployment of rivers, roads etc., resettlements 
and translocation of species, and repair of mining damage. 

Methodology  of  financial  provision  calculation  and  verification:  In  order  to  assess  the 
stock of reclamation obligations, the areas used by the open pit and not yet reclamation 
were  determined  from  the  current  survey  data.  There  are  also  areas  in  the  rear  area 
that  have  not  yet  been  reclaimed.  These  are  e.g.  areas  for  day  facilities,  coal  bunker 
systems, open pit exits, etc. The maps of the planned end of reclamation status form 
the basis of the allocation of the areas to the reclamation goals of forestry and agricul-
ture, e.g. from the final operating plan or, if not yet available, from the general operating 
plan / brown coal plan. 

Figure 84: Methodology of financial provision calculation (Tudeshki & Pielow, 2018) 

The terrestrial re-use of the open-cast mining areas takes place both in agriculture and 
forestry, and in the form of other uses, e.g. conservation or military training area. Start-
ing  from  the  lignite  plan,  the  level  of  detail  of the reuse was increased via the frame-
work of operating plans up to the final operating plans, the specifications of which are 
implemented with a strict focus. Figure 58 shows the schematically accounting for the 

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inventory.  The  reclamation  target  for  the  entire  mining  area  can  be  recognized  within 
the black mining boundary using the different colours. The basis for accounting for the 
future  re-cultivation  of  open-cast  mine  areas  is  the  timely  planning  of  the  open-cast 
mine development with extraction and tipping levels. Due to the long running times of 
lignite opencast mines, the planning accuracy for medium and long-term periods must 
be differentiated. 

Figure 85: Methodology of financial provision verification: Distribution of the closure 
cost due to objectives (left. Legend: OC open cast, IL – industrial landfill), FG allocation 
due type of activity (right) (Tudeshki & Pielow, 2018) 

Results  of  financial  provision  verification:  Figure  86  shows  the  distribution  of  the  clo-
sure cost due to objectives and the FG allocation according to activity type. For devel-
opment of the open pit hole is needed the largest part of the budget, at over 50%. Rec-
lamation and relocation, each have a share of around 12% of the total cost, while ge-
otechnical protection followed by dismantling and the collective category “rehabilitation 
of landfills, disposal of contaminants and archeology" sum up each with around 8%. 

Figure 86: Distribution of the closure cost due to objectives (left. Legend: OC open 
cast, IL – industrial landfill), allocation of the financial provisions due type of activity 
(right) (Tudeshki & Pielow, 2018) 

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Assessment results and conclusions: The mining-related financial provisions are to be 
formed taking into account the real development of the open-cast mine and to be used 
or  consumed  at  the  appropriate  time.  As  a  result  of  the need to use the raw material 
ahead of time to excavate the resource and, at the same time, to create the basis for 
reclamation and reuse, which is technologically necessary, the creation of the financial 
provisions at the time of use must be started to secure financial resources for the sub-
sequent reuse. 

Decisive for the amount of the provision formation is not quality and quantity of the land 
and infrastructure used, but rather quality and quantity of the reusability, which is to be 
created at the exact same point by the development of the open-cast mine. These re-
sult  primarily  from  the  lignite  plans  with  their  binding  goals  of  spatial  planning  for  the 
main  features  of  the  type  of  reuse  and  the  mining  law  permits  in  line  with  these  re-
quirements  in  the  form  of  framework,  main  and  final  operating  plans  according  to  the 
Federal Mining Act of Germany. 

Summing up the results, following conclusions apply: 

•  The overall result of the plausibility and completeness verification confirms that 
the  measures  on  which  the  financial  provisions  of  the  operator  are  based  are 
overall plausible and complete 

•  The methodology used by the operator to calculate the required amount of min-

ing-related provisions was assessed to be valid. 

•  The  level  of  the  mining-related  financial  provisions  for  the  recovery  was  as-

sessed to be viable.  

Finally, the sensitivity analysis and critical examination of the practice of current provi-
sion accounting was carried out.  

The  financial  provision  made  on  a  legal  basis  in  accordance  with  the  German  Com-
mercial Code shows a permanent deficit between the nominal funds required at a cer-
tain point in time and the available cash value, 

•  The design of the remaining extraction hole is a process downstream to open-
cast mine operation. The deficit in the design of the residual space arises due 
to the accumulation of the degree of carbonization. The deficit is greatest short-
ly  after  starting  the  extraction.  The  closer  the  dismantling  approaches  the 
planned end of mining, the smaller this deficit becomes. 

•  Reclamation services are already implemented during operation. In the case of 
reclamation, the basis for the formation of provisions is the complete obligation 
on  the  respective  balance  sheet  date.  The  deficit  therefore  only  results  from 
discounting. 

Finally, the following general statement was made: “The sensitivity analysis shows that 
there is a disproportionate increase to over 100% if the duration of the open-pit mining 
is extended by only 25%. This also means that open-cast mines with longer extraction 
phases have higher deficits. The impact of increasing the cost of the design of the re-
maining extraction hole is enormous. Staggered reclamation measures and the change 
in the adjusted interest rate play a relatively minor role in relative terms." 

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4.9.4  Industrial Minerals Mining 

Show  cases  for  industrial  minerals  mining  comprise  salt  mining  and  fluorspar  mining 
examples. 

Salt mining  

The case study concerns a salt mine with an attached plant for the production of pot-
ash fertilizer salts and for the extraction of industrial and table salt in Morsleben, Ger-
many. It was operated from 1897 until the 1990s and then closed. The salt mine is re-
used as a repository for radioactive waste. Based on extensive investigation programs, 
a  decommissioning  concept  for  the  site  was  developed,  which  takes  into  account  the 
complicated geological, geotechnical, mining and long-term security requirements. It is 
designed in such a way that the protection goals are maintained over long periods (at 
least 1 million years). 

The  long-term  safe  closure  of  the  radioactive  waste  from  the  biosphere  is  to  be 
achieved with the concept of the extensive filling of the mine and the seals in the vicini-
ty of the storage areas west-south field and east field. For this purpose, around 75 per-
cent of the cavities are to be filled, 22 seals are to be built and the Bartensleben and 
Marie shafts are to be sealed and filled. 

Figure 87: Underground closure of Morsleben salt mine type (Bundesgesellschaft für 
Endlagerung, 2016) 

The seals delay the access of solutions to the storage areas and the radioactive decay 
of  the  solution  until  the  radionuclides,  and  in  particular  those  with  short  disintegration 
times, will then have largely disintegrated. The direct connections to the top, the Bar-
tensleben and Marie shafts, are sealed with particularly high-quality seals. The princi-
ple diagram shows the following figure: 

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Figure 88: Underground closure of Morsleben salt mine (Bundesgesellschaft für Endla-
gerung, 2016) 

After approval of the planned closure, the work will take 15 to 20 years more from now 
until the complete closure. 

Fluorspar mining 

The show case concerns former fluor and bar spar mine that was opened in 1972 and 
operated  until  1985.  The  adit  was  opened  as  a  conveyor  and  drainage  tunnel.  After 
approx. 1.4 km in length it reaches the fluor spar deposit in 150 m depth. The deposit 
was opened up via the 1st adit floor, until 1982 the 2nd and 3rd adit floors were driven 
up.  The  total  production  was  approx.  200,000  tons,  with  a  fluorite  content  of  approx. 
60%, was extracted. Most of the material conveyed was processed by truck. The adit 
system  is  abandoned  and  not  used  anymore.  No  use  is  planned  in  the  future  either. 
The mine was closed and dismantled shortly after 1985. 

For safety reasons, the adit entrance was closed by a wall, in the lower area of which 
there  is  a  basic  drainage  of  the  tunnel  water.  According to the safekeeping operating 
plan,  selected  adits  were filled  with extracted mineral fill  material from the mine area. 
Over time, iron hydroxide sludge has accumulated in the adit system. This sludge rep-
resented a potential hazard with regard to the sudden mobilization. Therefore, several 
measures were implemented to reduce both sludge generation and uncontrolled sludge 
leakage into the receiving river: 

•  Construction of a 1.5 m high and 0.5 m thick concrete dam into the adit 

•  Sealing the gallery to reduce air access and thus the formation of iron hydrox-

ides 

•  Closure of the adit entrance (no uncontrolled access to the adit where iron hy-

droxide sludge can be released) 

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•  Creation of orderly drainage conditions with drainage of the adit mine water via 

a pipe system (avoidance of uncontrolled drainage conditions) 

•  Redirection of the adit mine water via a retention basin for any sludge potential-

ly mobilized inside the adit. 

Since the beginning of 2005, an airtight seal has been used to prevent or minimize oxi-
dation  processes  in  the  mine.  In  2006,  the  renovation  work  began,  the  main  effect  of 
which  was  the  sinking  and  separate  drainage  of  the  pit  water  to  the  river  basin.  The 
stream between the adit entrance and a collecting basin is therefore free of mine water. 
In the meantime, the chemical composition of the mine water began to change gradual-
ly, i.e. a low pH, resulting increased iron loads and, high salt loads (chloride, sodium, 
calcium), that where meanwhile determined to be of geogenic origin. 

Geotechnical stability also represents a potential hazard, as the adit are sometimes at 
risk of breakage and thus pose a long-term hazard to the surface. This poses a threat 
to public security. In the event of an adit wall breaking, there is a risk of flooding in the 
local area. The aim of rehabilitation is further to prevent the transfer of pollutants from 
the mine water into the receiving rivers. The remedial goal for people is to eliminate the 
currently  relevant  threats,  in  particular  accessibility.  From  an  environmental  point  of 
view and the need for mining damage, the adit system must be renovated and restored 
in such a way that the durability of all underground mine openings is guaranteed. 

Figure 89: Current situation at the fluorspar mine site: adit with mine water outlet (left); 
aeration zone for mine water passive treatment of the drainage water (right) 

To  improve  the  situation  on  the  long  term,  a  variant  assessment  was  prepared.  The 
basic  rehabilitation  options were assessed by discussing the long-term environmental 
influences  (environmental  compatibility),  the  necessity,  the  feasibility  or  effectiveness 
(suitability),  the  proportionality  and  the  assessment  of  the  effects  on  further  remedial 
measures. Further was prepared a cost-benefit-analysis. 

In principle, following groups of variants were assessed: 

a)  maintaining the existing state, taking into account lower environmental goals, 

b)  treatment of the already leaked mine water, 

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c)  adit refurbishment through refurbishment work in the gallery with closure of the 

hydraulic pathways, 

d)  Dilution of the mine water that is already discharged. 

As  preferred  solution  was  concluded  a  two-stage  process  that  foresees  a  temporary 
solution, in the first step this is the transfer of water from an uncontaminated water res-
ervoir  to  the  discharge  outlet.  Afterwards,  an  adit  rehabilitation  should  be  aimed  for, 
with  full  refurbishment  of  the  closed  mine,  keeping  the  adit  open  for  constant  water 
management in combination with the introduction of a SAPS (successive alcalinity pro-
ducing system) inside the adit. The resulting gross costs, based on a 10-year time in-
terval, are estimated to € 3.3 million with an uncertainty surcharge. 

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5.  Part D: Cost Profile, Cost-Relevant Activities and Unit Cost 

5.1  Data Base and Approach 

The overall scope of part D is to provide support for establishing financial data on the 
closure process. This includes also the design process, as the engineering cost of the 
closure  design  must  be  covered  through  FG  as  well  as  updates  of  the  design  might 
affect FG periodic adjustment. 

Cost profiles and unit cost in section 5 were obtained from about 30 closure plans and 
related  Bills  of  Quantities  (BoQs)  from  implemented  mine  closure  activities  (aggre-
gates,  ores,  industrial  minerals)  of  the  last  20  years,  mainly  from  Northern,  Western 
and Eastern Europe. The data were complemented with information from comparable 
rehabilitation  works,  for  instance  landfill  closure  and  aligned  with  information  on  unit 
cost  provided  by  the  MS.  Furthermore,  the  data  base  was  complemented  with  infor-
mation from several unit cost data bases for landscape rehabilitation, for instance the 
Performance  Book  Brownfield  Rehabilitation  and  Spatial  Development  as  of  2014 
(https://www.labo-deutschland.de/Leistungsbuch-Altlasten-und-
Flaechenentwicklung.html). 

5.2  Cost Profiles of Engineering Works 

5.2.1  Cost estimation, Bills of Quantity and Procurement rules 

Each mining activity needs a mining license/concession that will be issued by the com-
petent authority based on a Feasibility Study. The FS must address the entire intended 
life span of the proposed activities, from construction phase to post closure monitoring 
and  it  must  be  supported  by  all  types  cost  that  characterize  a  mining  activity:  invest-
ment cost, maintenance cost, and operational cost as well as calculated income for a 
certain  production  capacity  and  a  considered  product(s)  selling  price(s).  This  require-
ment  applies  also  to  the  mine  closure  phase  that  is  the  key  activity  financed  through 
the deposited FG. Further, a cash flow showing expenses and incomes must be a part 
of the FS. 

In the majority of the MS are available specialized software tools for cost estimate that 
have an updated price data base including the applied up to date working norms and 
taxation. Links to such software are: 

https://shop.weka.de/bau-immobilien/baudaten-und-baukosten  

http://www.wesa-software.de/html/datenbanken_sj_kosma.html#BKI  

 http://www.softwareparadiso.it/areef.htm 

https://www.capterra.es/directory/30056/construction-estimating/software 

https://www.labo-deutschland.de/Leistungsbuch-Altlasten-und-
Flaechenentwicklung.html 

FS is based on the mine closure plan providing all dimensions, technical and financial 
of the mine closure and environmental rehabilitation. Mine closure plans shall be con-

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sistent with the permits in force and have to reflect all permit conditions. The FS must 
provide  a  basic  design,  the  requirements  for  consultancy  and  supervision,  as  well  as 
environmental monitoring and reporting that are related to inspection by the competent 
authority. The cost concluded in the FS represents estimation and serves basically the 
establishment  of  the  fund  estimate.  Based  on  the  FS  is  prepared  the  Basic  Design, 
followed  by  the  Detailed  Design,  and  the  Final  Design.  Beginning  from  the  Basic  De-
sign  phase  are  developed  Bills  of  Quantities,  a  document  used  in  tendering  in  which 
materials, parts, and labour are itemized. It also details the terms and conditions of the 
construction or repair contract and itemizes all work to enable a contractor to price the 
work for the bidding. The closure activity is subject to procurement. 

Procurement  rules  exist  in  most  countries  and  for  all  financing  agencies.  These  rules 
shall encourage open competition in tendering and contract award, open meetings and 
equitable  and  fair  distribution  of  information,  effective  monitoring  and  auditing  of  all 
processes and implementation activities. After a successful procurement, the contract 
with the construction company will be made. World widely used conditions of Contract 
were published by the Fédération Internationale des Ingénieurs-Conseils (FIDIC). Rel-
evant  for  tendering  and  contracting  mine  closure  and  environmental  rehabilitation 
works are:  

FIDIC RED BOOK 

Conditions of Contract for Construction for Building and Engineering works designed by 
the Employer, Second Edition, 2017. The Red Book provides conditions of contract for 
construction works where the design is carried out by the Employer. The current Red 
Book  bears  little  resemblance  to  its  predecessors.  Earlier  versions  of  the  Red  Book 
were drafted for use on civil engineering projects. The current edition drops the words 
“civil engineering” from the title and this signifies a move away from the Red Book only 
being applicable to civil engineering works. In line with the rest of the FIDIC suite the 
focus is now more on type of procurement rather than the nature of the works. The Red 
Book is therefore applicable to any construction works were the Employer carries out 
the design. 

FIDIC YELLOW BOOK 

The Second Edition of the Conditions of Contract for Plant and Design-Build, Second 
Edition,  2017.  The  Yellow  Book  is  therefore  applicable  to  the  provision  of  electrical 
and/or  mechanical  plant,  and  for  the  design  and  execution  of  building  or  engineering 
works. Under the usual arrangements for this type of contract, the Contractor designs 
and  provides  the  works  in  accordance  with  the  Employer’s  requirements  which  may 
include any combination of civil, mechanical, electrical and/or construction works. 

FIDIC EMERALD BOOK 

Conditions of Contract for Underground Works (2019 Emerald book). The First Edition 
of the “Conditions of Contract for Underground Works” (Emerald Book) has been pub-
lished  by  the  Fédération  Internationale  des  Ingénieurs-Conseils  (FIDIC)  in  a  joint  en-
deavour  with  the  International  Tunnelling  and  Underground  Space  Association  (ITA-
AITES). 

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5.2.2  Site Investigation 

Each mineral deposit is unique, so planning must take into account the detailed nature 
of  the  resources  that  are  the  subject  of  mining.  Nature  and  sensitivity  of  the  environ-
ment must be considered through the monitoring and data collection system in order to 
provide environmental constraints for mining planning. 

•  Establishment of baseline or current conditions; 
•  Provision of site-specific input for use in the safety assessment of the proposed 

designs. 

5.2.3  Feasibility Study 

‐

The  FS  is  the  documentation  that  includes  the  main  characteristics  and  tech-
nical
economic parameters of the project, through which the rational and efficient use 
of  the  capital  and  material  expenses  is  ensured,  in  order  to  meet  the  economic  and 
social  requirements  in  the  respective  field.  It  contains  basic  information  on  geological 
setting;  mineral  deposit  description;  exploration  and  results;  mineral  resources  and 
reserves  estimates;  mineral  processing  and  metallurgical  testing;  mineral  and  land 
ownership; mining process; mine closure plan; infrastructure; permitting; local environ-
ment; etc. 

Furthermore, usual contents for the FS written sections are: 

•  General data: Name of project Designer 
•  Contracting authority 
•  Location (county, locality, street, number) 
•  Subject,  with  substantiation  of  the  necessity  and  opportunity  considered  upon 

approval of the pre

feasibility study 

•  Functional  and  technological  description,  including  technical  studies,  on  disci-

plines 

‐

•  Technical data on the project 
•  Area and legal status on the lands to be taken (definitively and/or temporary) by 

the project 

•  Geo

physical characteristics of the site (seismic zone, nature of foundation land 

and conventional pressure; maximum level of water table) 

‐

•  Main characteristics of constructions 
•  Estimated overall cost of project 
•  Total investment value, detailing on the yearly overall cost estimate. 
•  Main technical
economic parameters of project 
•  Total  value  (in  prices 

  month,  year),  of  which:  constructions

schedule (Investment/Construction + assemblage) 
‐

‐

Project financing and its splitting according to the financing sources. 

assemblage, 

‐

5.2.4  Technical Design 

The technical design (TD), verified, endorsed and approved according to the legal pro-
visions, is the documentation, written and drawn based on which the works are execut-
ed. Within the description of the works forming the object of the technical design refer-
ences will be made on the following elements: 

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Textual part consisting of general and particular technical specifications providing for: 

• 

location,  topography,  climate  and  natural  phenomenon  specific  to  the  region, 
geology, seismicity; 

•  project description on volumes, brochures, chapters; 
•  construction  site  organization,  brief  description,  demolitions,  network  diverting, 

etc.; 
temporary access ways; 

• 
•  sources of water, electricity, gas, phones, etc. for the construction and operat-

ing phase; 

•  access ways, communications, etc. 
•  program for works execution, schedule of works, acceptance programs; 
•  mapping and measurement of works; 
•  contractor’s (tenderer) laboratory and tests he is responsible for; 
•  cleaning within construction site as well as sanitary services; 
• 
•  Provisions on procurement procedures, consultancy, technical assistance, fees, 

required additional technical studies, on disciplines; 

taxes, levies, as well as contingencies. 

Bills of quantities (BoQ) 

Quality management plan (QMP) 

Drawings 

5.2.5  Supervision 

The  scope  of  the  supervision  is  to  ensure  that  the  project  is  completed  on  time,  on 
budget  and  complies  with  the  relevant  regulations  and  quality  standards.  Supervision 
comprises the following activities: 

•  Design supervision 
• 
•  Site  supervision  in  accordance  with  technical  and  construction  legal  require-

Independent third-party verification and certification 

ments 

•  Commissioning supervision on quality and schedule 
•  Technical and legal advice, and assessment consulting 
•  As-built documentation. 

5.2.6  Occupational Health and Safety 

Working on construction sites requires an Occupational Health and Safety Plan accord-
ing to European requirements. In the ideal case, the contractor is required to implement 
an Occupational Health and Safety Management System according to ISO 45001.  

At  all  stages  of  the  rehabilitation  and  management  process,  it  is  essential  to  consider 
and address the risks to the health and safety of all persons who may be affected by 
activities at the site. People to be included in this consideration include:  

•  site users and occupants (if any), 

•  all workers on the site, 

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•  visitors to the site (for example, couriers), 

•  people travelling across the site or near the site, 

•  site neighbours (as appropriate).  

Monitoring  of  health  and  safety  must  be  on-going  through  all  stages  of  assessment, 
rehabilitation and management because known and unknown hazards can be encoun-
tered at any stage of site works. Generally following types of hazards are to be consid-
ered: 

•  Handling of heavy machinery, 

•  Use and handling of hazardous substances, 

•  Potentially dangerous site conditions, 

•  Handling of radioactive material - radiation protection (if applicable). 

Work on contaminated sites requires the use of a range of personal protective equip-
ment and clothing (PPE). PPE includes a wide range of clothing and safety equipment, 
such as boots, face masks, hard hats, ear plugs, respirators, gloves, safety harnesses, 
and  high  visibility  clothing.  The  cost  of  all  Occupational  Health  and  Safety  measures 
are needed to be included into the costing. 

5.2.7  Environmental Monitoring 

Scope  of  environmental  monitoring  is  the  verification  of  compliance  with  regulations, 
discharge authorizations and procedures as well as the verification of the effectiveness 
of engineering designs. The benchmark for the verification is the baseline data collec-
tion of the FS. 

5.2.8  Environmental Reporting 

Environmental reporting obligations are set via permits by the competent authority. 

5.3  Cost Profile of Technical Works 

Extraction-related  activities  are  referred  to  in  Annex  II  of  the  Public  Procurement  Di-
rective (2014/24/EU) (public works contracts) at 45.11: earth moving: excavation, land-
fill,  levelling  and  grading  of  construction  sites,  trench  digging,  rock  removal,  blasting; 
site  preparation  for  mining;  overburden  removal  and  other  development  and  prepara-
tion of mineral properties and sites; test drilling, test boring and core sampling for con-
struction,  geophysical,  geological  or  similar  purposes.  Funds  available  to  the  compe-
tent  authority  in  the  above-mentioned  case  should  be  used  as  public  money  and  the 
works should be carried out following a tender. If the mining operator enters into bank-
ruptcy  the  designing  solutions  will  require  updating;  also,  the  carrying  out  of  environ-
ment works involves the prior obtaining of approvals, permits and agreements. If is the 
case to spend the FG, the competent authority will have to put into practice the mine 
closure according to the Mine Closure Plan (a version that is updated to match all per-
mit site specific conditions). 

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5.3.1  Site Preparation 

The  preparatory  work  may  contain  the  following  steps  (not  all  types  of  works  are  re-
quired at all sites): 

• 

topographic works (compulsory works), 

•  deforestation of trees and shrubs, 

•  cleaning the land, mechanized scarification, 

•  uncovering the vegetal layer or the degraded land, 

•  demolition  of  some  old  constructions  and  the  transport  of  the  resulting  materi-
als, works complementary to the works of earthworks (the depletion of surface 
waters on the land intended for future construction). 

It  is  necessary  to  create  social-administrative  spaces,  to  ensure  the  living  conditions, 
storage of materials, etc., networks for utilities and installations related to their produc-
tion, communication paths, as well as workshops (carpentry, blacksmiths, mechanics, 
etc.),  prefabricated  polygons,  concrete  stations,  mortar,  ballast  and  quarries  stations, 
etc. In the case of mine closure and environmental rehabilitation works there would be 
already  existing  infrastructure  available  for  the  selected  third-party  company  to  be 
used. The contractor must check the situation and establish a  site-specific budget for 
site preparation. If the existing infrastructure and buildings are to be removed according 
to the last approved version of the Mine Closure and Rehabilitation Plan, then the con-
tractor will need to install temporary facilities.  

Figure 90: Site preparation 

Ground cleaning operation represents the removal from the ground of the residues of 
wood material from the deforesting, of the stones, of some industrial waste or even of 
the  vegetation  of  bog.  It  is  possible  to  work  with  several  machines  simultaneously. In 
order to remove the pond vegetation, water drainage and water removal measures will 
be taken first. The vegetation can be best removed with two-piece gravel bucket exca-
vators.  The  transport  is  done  with  the  dumper.  Cranes  and  dumpers  can  be  used  to 
collect and dispose of large waste. The small waste will be collected by bulldozers and 
front  loaders  and  will  be  transported  by  dumpers.  The  used  loaders  can  have  metal 
wheels with crampons and cups made of metal grids. 

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5.3.2  Earthworks 

The  main  earthworks  are  excavations  and  fillings.  Other  earthworks  are  levelling  and 
compaction. The volumes of these earthworks are measured as follows: 

•  excavations: the earth in its natural state (before excavation, unpaved) 

• 

fillings: the ground put into work and compacted according to the project 

The dimensions of the excavations are: length, width, the depth to the working height 
or the height to the working height. The level curves according to a situation plan rep-
resent the intersection of the natural relief with level plans (horizontal). On a situation 
plan, a horizontal plan is parallel to the level curves and the maximum slope line of the 
terrain is perpendicular to it.  

The earthworks are represented in the project by location plans that outline the works 
to be executed, with the necessary details. The calculation of the volumes of the earth 
works can be done: 

• 

• 

in the case of long works in relation to the other dimensions: channels, dams, 
ditches, etc. 

in the case of works with a large surface area in relation to the depth of the ex-
cavation (height of filling): platforms and systematization of lands, etc. 

The following are the main earthwork activities in mining site rehabilitation: 

Reshaping 

Re-profiling  of  the  waste  rock  body  is  a  fundamental  requirement  in  achieving  long-
term  geotechnical  stability.  From  a  re-profiling  point  of  view  can  be  distinguished  two 
distinct technical approaches: 

• 

• 

relocation of excavated material within the waste rock heap; 

relocation of excavated material outside the site. 

Re-profiling of embankments and slopes 

The outline of the landfill storage facility aims to: 

• 

facilitating the installation of a stable long-term final cover, 

•  directing the running water from the re-profiled areas to the surrounding areas. 

The profiling of the dam aims to: 

•  obtaining a stable surface in the long term and resistant to erosion; 

• 

• 

facilitating the installation of a final erosion resistant cover and reducing infiltra-
tion (if necessary); 

landscape integration of waste storage facilities. 

The long-term stability of the dam and the slopes includes static and dynamics, as well 
as resistance to wind and water erosion. In the case of processing wastes and for vari-
ous  types  of  loading  (dynamic,  static),  optimizing  the  rehabilitation  process  may  con-
sider reducing the content of water in the pores of the processing tailings body and the 
lowering of the water level.  

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To  ensure  stable  drainage  conditions  of  TMFs,  it  is  advisable  accelerating  consolida-
tion  in  areas  along  the  drainage  ditches  where  packages  of  fine  tailings  with  large 
thicknesses  and  / or    characterized by different degrees of sedimentation are found 
(forced consolidation through solid material). 

Pavements within the mine site are generally constructed in the form of flexible pave-
ments which are layered systems with better materials on top and inferior materials at 
the bottom. Gravel roads are used as base material. In mine closure pavement would 
be made by using local suitable materials to minimize cost. Reuse of tailings for road 
construction is a trend lately. Rip-rap layers are often installed at the base of cover lay-
ers.  

Earthwork cost is very site specific and it will depend on the volumes and nature of the 
material  that  have  to  be  manipulated  including  of  both  initial  and  final  locations  of  it. 
Equipment for extracting, loading, transport, and unloading, spreading, levelling, com-
pacting  and  other  necessary  operation  in  order  to  put  the  design  into  practice  will  be 
chosen to optimize cost for a site specific situation. 

5.3.3  Fencing and Drainage 

Fencing 

Fencing of hazardous areas, where it is possible to do so, involves installing a physical 
obstruction to reduce the risk of unintentional entry into dangerous areas. Fencing acts 
as a warning, not a barrier: as with marking, where individuals are determined to enter 
affected areas, fencing will not prevent them from doing so. Fencing strands may be of 
any  suitable  durable  material      including  wire,  string,  synthetic  cord  or  tape.  Uprights 
may  include  trees,  buildings  or  existing  structures  and  posts  erected  as  part  of  the 
warning system. Warning signs must be attached to the top strand of the fence. Wher-
ever  fencing  is  erected,  it  must  be  monitored  and  maintained  to  ensure  its  longevity. 
This can require significant resources. Special facilities would require installing chain-
mesh/chainwire security fencing. Cost will be given by the type of fence, length and the 
location where the fence will be installed, and it will be site specific. 

Drainage 

In this category are included the works of removing of water from the site on which the 
earthworks are to be performed. Removal of surface water that flows on the site can be 
done by the following methods: 

• 

the  creation  of  channels  (gutters)  for  gravitational  drainage  of  water  to  neigh-
bouring areas with lower elevation or to the outlets (rivers, lakes, sea, ocean), 

•  creation of a drainage system (pipes or ditches filled with granular material), 

• 

the creation of wells from which to pump water, 

•  direct water pumping. 

To  prevent  water  infiltration  to  the  site,  works  can  be  carried  out  upstream  to  collect 
waters and direct them to areas of no interest, to water treatment stations or even to a 
sewerage system. 

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5.3.4  Demolition / Decommissioning 

When old buildings or parts of buildings are found on the site, they will have to be de-
commissioned and the resulting material will be transported to a storage place estab-
lished and approved by the local and environmental authorities. There are two catego-
ries of constructions that may be subject to demolition: 

•  constructions developed vertically, 

•  constructions developed at ground level or buried. 

The demolition technologies depend on the shape and size of the construction and are 
designed according to the used equipment: the bulldozer, the hydraulic excavator, the 
crane  with  metal  ball  hanging  in  the  hook,  the  machine  with  telescopic boom bearing 
platform, the pneumatic or hydraulic hammer mounted on the excavator, drilling instal-
lations with thermal torch or hydraulic spear (monitor gun). Pneumatic hammers or oth-
er  hand  tools  (hammers,  chippers,  welding  machines  for  cutting,  electric  saws,  etc.) 
can  also  be  used.  In  certain  situations,  it  is  possible  to  resort  even  to  the  demolition 
with the help of excavators, explosives, etc. 

Material  resulting  from  the  demolition  can  be  loaded  with  excavators,  front  loaders, 
claws  and  cranes  and  will  be  transported  by  trailers,  dumpers  or  hand  machines 
(wheels, dumpers, etc.). An important action during the demolition of the underground 
works  as  well  as  later,  during  the  execution  of  the  works  of  earthworks  and  founda-
tions, is the identification and protection of the networks of electricity, water, sewerage, 
gas, telecommunications, etc. These networks must be specified on the situation plan 
and  in  the  field  by  picketing  with  stakes  or  other  signals.  Cost  of  demolition  must  be 
evaluated based on dimensions, location and the foreseen technology. 

5.3.5   Placing Back Extractive Waste into Excavation Voids 

There are three types of fill that can be performed simultaneously with the mine opera-
tion or at its completion, there is also the alternative of closing without filling: Total refill-
ing can be done by mining mass transfer (if the operation is on-going) or by relocation 
of sterile material, including landscaping. Partial fill or stabilization of slopes is put usu-
ally in practice to mitigate or modify visual impact and to increase the stability of the pit 
slopes. Sometimes it is used as a compromise solution meant to replace total fill. Sim-
ultaneous refilling is usually used at mine sites with multiple quarries where execution 
plans  allow  direct  storage  of  sterile  rocks  in  one  of  the  quarries  (indoor  waste  rock 
heaps).  Figure  91  illustrates forms of filling. For the mine operator, pit fill  could mean 
shortened  and  potentially  less  costly  downhill  haulage  routes,  and  a  potential  way  to 
dispose of reactive (acid-generating) waste rock.  

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Figure 91: Scheme of an open-pit mine morphological reclamation, including landscap-
ing possibilities. (a) Complete filling for restoration of the original agroforestry uses or 
the implementation of new uses, (b) partial filling for rehabilitation of pre-mine uses for 
implementation of new uses (e.g. recreation), (c) minimal selective filling and treatment 
of rock faces, tips, and embankments for replacement activities (e.g. recreation, lakes, 
wetlands), and (d) maintenance of morphological characteristics of the open pit with 
vegetation development (Favas et al. 2018) 

This method is advantageous from the point of view of costs, reduces the surface area 
and volume of the waste rock heaps, decreasing in the same time efforts to remedy the 
waste rock heaps and allowing productive use of land in the post-closure phase.  

Filling of drilling holes and other excavations: 

Underground holes (especially near the surface), exploration drill holes and discovery 
areas that can contribute to surface destabilization, must stabilized by filling. If the loca-
tion of an underground void is not known exactly, investigative drills and video surveys 
will be carried out to enable accurate understanding of the situation of these goals. For 
filling of underground holes, drill holes and other open areas, the same materials can 
be used as in the case wells and galleries.  

5.3.6  Relocation 

Depending on the pollution potential, the size and volume as well as the availability of 
an alternative location, the closure solution for mine waste heaps might be relocation. 
Practically, mine waste heap material can be used as consolidation material for TMFs 
or  for  filling  of  open  cast  mining  sites.  In  such  a  case,  the  material  will  be  hauled  by 
dozers and transported by trucks to the alternative disposal location.  

5.3.7  Groundwater Protection through Cut-off Wall 

A  cut-off  wall  is  a  waterproof  underground  wall,  which  on  the  one  hand  prevents 
groundwater from flowing into the opencast mine, on the other hand secures the natu-

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ral groundwater level in the vicinity of the opencast mine and thus protects water bod-
ies and wetlands. The use of a sealing wall is linked to certain geological conditions.  

5.3.8  Shaft and Adit Closure 

A  shaft  is  defined  as  a  vertical  or  inclined  permanent  opening  that  gives  access  and 
services various levels of a mine. An adit is an entrance to an underground mine which 
is  horizontal  or  nearly  horizontal.  An  Illustration  of  typical  shafts  and  adits  is  given  in 
figure 92. 

Figure 92: Illustration of possible shaft (left) and adit (right) entrances 

Shaft closure 

The  type  and  dimensions  of  the  opening  to  be  treated  govern  the  choice  of  closure 
method. The size, shape, depth of shafts determines the necessary quantity of material 
for filling and design-sizing other safety techniques. The full filling technique requires to 
establish the number, size and extent of connections with other openings (shafts, tun-
nels) and of the main service area at the lowest level. Knowledge of voids located at a 
shallow  depth  close  to  the  works  (abandoned  infrastructure  or  tunnel,  underground 
worksite) is important, irrespective of the selected method of treatment. The presence 
of cavities or ducts must absolutely be assessed when there is a risk of escape of mine 
gas, which can migrate into the voids. The potential presence of pollution vectors in the 
abandoned works (waste, acid mine water) should be assessed to evaluate the effects 
of water on the closing-off works. An important aspect to consider for the evaluation of 
shafts long-term stability is the possible degradation of the materials (shaft lining, cap-
ping, plug). 

Taking into account the excess costs generated by problems of maintenance and safe-
ty, permanent sealing-off of the openings appears preferable. If access is required, the 
used  techniques  should  limit  the  risks  and  render  them  acceptable.  Costs  should  in-
clude not only the safety works but also upkeep and maintenance. The filling of wells 
and  shafts  can  be  done  using:  crushed  hard  rock,  non-cohesive  rock  (gravel,  sand), 
sterile rock, waterproof, cohesive filler (concrete).  

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Adit closure 

Choosing the appropriate closing or rehabilitation technology depends on the following 
factors: the location of the gallery in relation to the surface, geological and hydrogeo-
logical  conditions,  function  of  the  gallery,  the  general  state  of  the  gallery  in  terms  of 
stability and accessibility. In order to achieve a correct closing of the abandoned galler-
ies, the following constructive solutions, compatible with best practices can be adopted: 

•  construction of a precast concrete or concrete dam at the mouth of the gallery 

• 

fill a portion of at least 10 m in length immediately behind the mouth gallery with 
a fill (the total length of the fill area varies depending on ensuring surface stabil-
ity on gallery alignment) 

•  complete refill of the gallery 

•  closing  the  gallery  mouth  by  detonating  the  galleries  sunk  in  view  of  restoring 

the natural environment 

5.3.9  TMF Dewatering/Stabilisation and Covering 

Main scope of those preliminary works of TMF stabilisation is a) to directly extract the 
supernatant water that is usually sent to a treatment plant, and b) to get access to the 
tailings material for the implementation of the vertical drains to extract the pore water 
for further stabilisation (figure 92).  

Typically,  the  supernatant  water  is  pumped  or  drained  off  to  take  off  free  pore  water 
from  the  surface.  Porewater  from  the  remaining  sedimentation  layers  are  drained  off 
through vertical drains. Holes are drilled into the processing sludge (typically 3 m deep) 
to introduce vertical drains. Stabilisation of the complete system is performed through a 
geogrid, underlain by geofabric and drain mats (Figure 92). In general, the layered sys-
tem is covered with 1 to 2 m of mineral soil or waste rock material to force tailings con-
solidation. A standard technique for forcing sediment consolidation is the subaquatic fill 
of extractive waste through hopper barge. 

In the upper, statically relevant fine slime areas, bonded geofabric vertical wick drains 
are  installed  accelerating both the consolidation process and the required increase in 
shear  strength.  Vertical  wick  drains  of  0.15  m  width  and  0.01  m  height  are  deployed 
and typically installed at 1.5 m in a triangular grid spacing. The geosynthetic elements 
are placed at a depth up to 8.0 m, the arrangement of the drains is adjusted to the con-
solidation properties and shear strength distribution of the underlying ground. 

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Figure 93: Stabilisation technology for tailings ponds: vertical drains in combination 
with a stabilisation package made of geofabric, drain mats, and geogrid. The system is 
covered with 1 to 2 m mineral soil or waste rock material to force consolidation (source: 
Wismut GmbH, 2019). 

After TMF geotechnical stabilisation, an appropriate surface sealing must be applied. 

5.3.10  Application of Surface Sealing 

Installing of a soil cover system on waste rock heaps pursues one or more of the fol-
lowing objectives: 

•  minimizing  the  volume  of  infiltration  and  percolating  water  through  the  waste 
rock  body  to  minimize  the  mobilization  of  pollutants  from  the  waste  into 
groundwater 

•  minimizing dust generation 

•  minimizing the penetration of oxygen into the body of the sterile rocks in view of 
avoiding the formation of acidic water, respectively of spontaneous combustion 

•  prevention of direct contact with hazardous waste 

•  development of a vegetation blanket for subsequent use 

From the point of view of the rehabilitation possibilities specific to the objective, typical-
ly the following types of coverage are used: 

•  Permeable dry covers  

•  evapotranspiration covers 

• 

Impermeable and low-flux dry covers 

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•  Oxygen-consuming dry covers 

•  Capillary barrier 

•  Multi-layer covers with or without geomembranes or other sealing elements 

•  Reactive covers. 

Figure 94: Installation of soil cover systems 

The  application  of  sealing  systems  requires  a  particular  quality  assurance  that  com-
prises the manufactured sealing element as well as the mineral soil to be used as cov-
er. Further, the workability of a sealing component and / or a system must be demon-
strated to the competent authority in a test field under construction site conditions be-
fore the sealing system is installed. In this context, the appropriate stability and sliding 
safety (according to the respective state of the art and in relation to the unfavourable 
on-site  situation,  e.g.  steepest  and  longest embankment area) must be demonstrated 
to the competent authority.  

Furthermore, quality management must be provided for every measure relating to the 
sealing  of  landfills  (basic,  intermediate  and  surface  sealing).  The  following  3-stage 
quality management system is state of the art: 

Prefabrication of materials / components / systems 

•  Self-monitoring of the manufacture by the manufacturer 

•  External monitoring of the production by a commissioned third party 

Construction on the construction site 

•  Self-inspection of the executing construction company 

•  External inspection by a commissioned third party (commissioned by the client), 

which must be confirmed by the competent authority 

Inspection through the Regulatory Body 

•  carried out by the competent authority 

The  external  auditor  must  have  sufficient  specialist  and  expert  personnel  and,  as  a 
prerequisite for official confirmation, the corresponding accreditations according to DIN 
EN  ISO  /  IEC  17020  (as  external  testing  body)  and  according  to  DIN  EN  ISO  /  IEC 

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17025 (as testing laboratory). The mine operator is responsible for the costs of the ex-
ternal inspection. 

Cover design for quarries and pits 

In the case of the cover project, the same principles apply as in the case of the covers 
installed on the waste rock heaps. The quarry configuration includes the general angle 
of the slope and the height / width of the berms. Stabilization and rehabilitation of quar-
ry’s slopes may vary from keeping the original configuration of the slope, to reducing it 
or to filling application. Many quarries are not covered but flooded. 

Construction of covers on TMFs 

Arrangement of a soil cover on the surface of the TMF system related to the processing 
plant  of  mineral  substances,  aims  to  fulfil  the  same  rehabilitation  objectives  as  de-
scribed for waste rock heaps. However, there are some specific problems that must be 
taken into account, namely: 

•  processing  tailings  usually  contain  large  amounts  of  pore  water,  often  at  the 
saturation  limit,  at  least  in  some  parts  of  the  tailings  pond  system,  that  inhibit 
consolidation 

•  Sedimentation  /  consolidation  of  the  processing  wastes  can  be  significant  in 
terms of subsidence. This must be taken into account to determine the optimum 
cover profile and installation technology 

•  Geochemical problems generated by the waste resulting from the processing of 

substances 

Industrial  minerals  are  more  complex  than  in  the  case  of  the  sterile  rocks  generated 
from  mining.  This  fact  influences  both  the  selection  of  the  types  of  cover  and  related 
technologies. 

5.3.11  Reclamation / Revegetation 

Vegetation  blankets  should  be  sown  with  grass  for  immediate  protection  against  ero-
sion,  afterwards  trees  or  shrubs  can  be  planted  for  stabilization.  If  the  predetermined 
conditions are met, the location of the waste rock heap may be left to the natural cycle 
of vegetation regeneration. To provide protection, temporary or permanent growth and 
normal  vegetation  development  may  be  preferable  the  enclosure  of  the  waste  rock 
heap. Natural regeneration cycles (natural succession) have the advantage of present-
ing low costs or even zero.  

The approach based on guided natural succession is based on the existence of natural 
analogues, such as certain biotopes, characterized by limited soil content and / or lo-
cally selective seeding / planting. This approach was designed to stimulate and speed 
up natural development processes. If the vegetation is to be installed on a multi-layer 
cover posed on the top of waste deposit that has also the role of stopping the entrance 
of the rain water into the waste material, than a special selection of the vegetation is to 
be carried out in order to avoid the damage of the insulation layer by the roots. Special 
maintenance  measures  against  bioturbation  must  be  used  and  this  has  a  high  cost 
influence. 

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5.3.12  Flooding 

Flooding is an integral part of the mine closure and rehabilitation process. After com-
pletion  of  preparatory  activities  (refilling,  stabilization,  removal  of  contaminated  ma-
chinery, recovery of recyclable metals, etc.), evacuation of mine water will be reduced 
and finally stopped. At this stage, the natural groundwater intake will lead to mine filling 
(figure 94, right). 

To avoid subsidence and damage to surface constructions, as well as to diminish the 
impact on the environment as a result of the increase of the groundwater level, flooding 
the shallow horizons of the mine must be controlled by draining water by drainage or 
pumping and by the application of purification measures if the quality of the mine efflu-
ents is not compatible with the direct discharge in natural receivers. It will be necessary 
to monitor the groundwater level and quality, but in the long term, monitoring activities 
will be substantially reduced or they will cease. Flood strategies have, to a large extent, 
a preventive character. The main components of a flooding concept are: 

•  knowledge of the problems of geomechanically stability associated with growth 

of hydrostatic level and establishing a controlled flood execution plan 

•  early commissioning of water treatment plants 

•  drainage pipes 

•  pumping, unloading and waste management installations 

• 

implementation of a monitoring system 

Flood concepts and strategies must be tailored to the site specifics. It's necessary con-
tinuous updating of the concept underlying flood and its adaptation in depending on the 
results of the flooding monitoring.  

Quarry/pit flooding 

Flooding  a  quarry  generally  offers  the  opportunity  to  create  new  ecological  habitats 
(figure  94,  left).  Depending  on  the  mineralogical  conditions  of  the  rock-free  surfaces, 
there are possibilities of generating acidic waters with high content of heavy elements 
at the quarry’s slopes level. Water management needs to be carefully planned so that 
does  not  endanger  wildlife.  If  the  acidic  water  generation  on  the  slopes  of  the  quarry 
cannot  be  prevented,  drainage  ditches  will  be  set  up  to  keep  water  from  the  slopes, 
away  from  the  vegetated  surfaces.  For  the  sustainable  management  of  quarry  lakes, 
most used techniques are the following: 

• 

• 

installation of waterproof clay layers to prevent infiltration into underlying rock 

the application of specific methods to increase the pH (if applicable) 

•  sealing the boreholes to prevent seepage 

•  diversion of running water, around the slopes rich in sulphur, in order to not af-

fect the lake water quality 

• 

in-situ water treatment in the quarry proved to be a successful solution in condi-
tions under which the minimization of generation and penetration of acidic wa-
ters can be ensured 

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Cost related to flooding is extremely site specific. A detailed calculation made by spe-
cialized designers is needed also for the assessment of long-term maintenance works 
and monitoring requirements. 

Figure 95: Flooding of a quarry (left) and a lignite mining site (right) 

5.3.13  Waste Disposal 

In  accordance  with  Article  5  of  the  Mining  Waste  Directive,  the  mining  operator  it  is 
obliged  to  develop  a  waste  management  plan  that  will  allow  minimization  the  volume 
generated, treating, recovering and storing the mining waste, taking into account of the 
principle  of  sustainable  development.  From  a  closure  point  of  view,  the  waste  will  be 
managed to reduce the degree of hazardous waste by: 

•  placing  extraction  waste  back  into  the  excavation  hole  after  extraction  of  the 
useful mineral substance, to the extent that is technically and economically fea-
sible and to the possible extent which corresponds to the environmental stand-
ards  at  community  level  and  the  requirements  of  the  EWD,  in  cases  of  rele-
vance; 

•  placing top soil to support vegetation on the former sites, after the closure or if 
this is not possible from the point of practical view, re-use of top soil elsewhere; 

The waste will also be managed to ensure secure short-term and long-term storage of 
extraction  waste,  in  particular  by  taking  into  account  these  aspects  during  the  design 
phase  or  by  managing  the  waste  during  the  operational  or  post-closure  period  by 
choosing a design solution that: 

• 

requires a minimum of control and management of the closed storage arrange-
ment or finally allows the monitoring to be waived 

•  prevents  or  at  least  minimizes  the  long-term  negative  effects,  for  example, 
those that can be attributed to the migration of atmospheric pollutants or aquat-
ics from the landfill 

•  ensures  the  long-term  geotechnical  stability  of  any  structures,  embankment  or 

waste rock heap that rises above the initial topographic surface 

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Non-acidic waste water waste 

In the case of waste that does not have a significant potential for generating acid water, 
the design criteria for the covering layer are the following: 

•  prevention of accidental access to waste 

•  providing vegetation support 

• 

improving the visual appearance 

•  prevention of dust formation from the surface of the waste 

•  erosion control 

Waste with potential of generating acid water 

If  the  potential  acid  waste  water  generating  waste  is  disposed  of  separately  without 
insulation  in  acid-free  waste,  the  design  criteria  of  the  cover  shall be included in plus 
the following: 

•  minimization of water infiltration in the mass of waste 

•  minimizing oxygen intake in the mass of waste 

Waste separation 

Mining  activities  may  result  in  sulphurous  rocks  which  may  have  a  potential  for  acid 
water formation. Sterile rocks will be separated by capacity for generating acid water. 
Separation and mixing of the sterile material according to the potential of acidity gener-
ation is part of the best available techniques category, which is advantageous from the 
environmental point of view and saves the efforts necessary to close the mines in from 
the point of view of the management of acid effluents. 

5.4  Cost-relevant Activities for the FG Calculation and Periodic Adjustment  

The cost items that contribute to investments include: 

• 

investment costs for technical works 

•  Related  investment  specific  costs  like  financing  and  program  management 
costs, planning, design and supervision costs, community mobilization and hy-
giene promotion costs 

•  Operation and Maintenance costs 

•  Variation of costs according to different implementation methods have to be an-
alysed  and  necessitate  division  of cost estimates into local available materials 
and purchased materials, unskilled labour and skilled labour 

Within  each  component/  technology,  a  consistent  Bill  of  Quantities  (BoQ)  has  to  be 
developed  based  on  engineering  estimates  that  can  be  verified  and  updated,  using, 
where  possible  the  lowest  unit  of  analysis  (plant,  labour  and  materials)  together  with 
preliminary and general items.  

Within each component/ technology, the identification of major underlying variables that 
have  a  default  value  but  which  also  can  be  adjusted  to  suit  regional  or  site-specific 
considerations. The regional variations like transport (e.g. average distances to region-
al commercial centres, proportion of gravel and tarred roads), hydro-geological condi-
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tions (e.g. drilling success rates, average depth and yield of wells and boreholes) and 
topographical conditions (e.g. average pumping heads for raw water, transmission and 
sewerage  have  to  be  considered.  Within  the  component/  technology  specific  BoQs 
must contain further detailed design variables that can be adjusted to fine tune the cost 
estimates to site specific situations. 

5.4.1  Site Investigation 

Site  investigations  usually  include  drillings  of  different  types,  toposurvey,  settlement 
and  water  balance  measurements,  stability  measurements,  sampling,  as  well  as  soil 
mechanical  and  chemical  analysis.  Further,  there  might  apply  geophysical  measure-
ments. Table 12 shows the unit price range for site investigations. 

Table 12: Unit price range for site investigations 

Description 

Topographical survey 

Unit 

Costs  for  the  first  topographical  survey 
incl. creation of site plans and cross sec-
tions (digital and analog) 
Survey  during  construction,  pegging  out, 
intermediate site plans and cross sections 
(digital and analog) 
Survey  after  the  end  of  construction,  as 
completed drawings (digital and analog) 
Restoration  of  boundary  stones  incl.  ca-
dastral survey 

ha 

ha 

ha 

lump-sum 

Technical site investigation 

Unit 

Drilling without well installation  

Up to 5 m depth   

Up to 10 m depth   

Up to 20 m depth 

Up to 50 m depth 

Up to 80 m depth 

Drilling with well installation 

Up to 5 m depth   

Up to 10 m depth   

Up to 20 m depth 

Up to 50 m depth 

Up to 80 m depth 

European Commission  

pc 

pc 

pc 

pc 

pc 

pc 

pc 

pc 

pc 

pc 

Low range 
[€] 

High range 
[€] 

600 

180 

806 

390 

1,000 

324 

1,250 

450 

Low range 

High range 

[€] 

150 

300 

2,000 

10,000 

20,000 

250 

2,000 

5,000 

20,000 

30,000 

[€] 

500 

800 

4,000 

30,000 

50,000 

700 

4,000 

10,000 

50,000 

80,000 

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Sampling from a well 

Up to 5 m depth   

Up to 10 m depth   

Up to 20 m depth 

Up to 50 m depth 

Up to 80 m depth 

Sampling surface water 

Up to 1 m depth   

Sampling surface soil 

Up to 1 m depth   

pc 

pc 

pc 

pc 

pc 

pc 

pc 

Analytics for site investigation 

Unit 

Soil mechanical Investigation  

Soil mechanic lab investigation  

Chemical Investigation 

GC-MS Screening 

Radiometric Investigation 

Spectrometric analyses 

pc 

pc 

pc 

100 

200 

350 

500 

750 

50 

50 

200 

400 

700 

1,000 

1,500 

150 

150 

Low range 

High range 

[€] 

150 

90 

90 

[€] 

400 

220 

220 

Investigation of water balance and sub-
stances transport (depending on size) 

Unit 

Low range 

High range 

[€] 

[€] 

Measurements for water balance  

Installation of climate station incl. data 
logger 

Soil water measurement equipment 

Installation of soil measurement station 

Evaporation measurements (TMF) 

Installation of evaporation pan incl.  

Calculation of water balance 

Consulting and reporting  

Pollutants assessment  

Consulting and reporting  

Substances transport modelling 

Consulting and reporting  

pc 

pc 

pc 

pc 

pc 

pc 

3,000 

7,000 

1,500 

5,000 

1,500 

5,000 

3,000 

15,000 

3,000 

15,000 

25,000 

60,000 

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financial guarantee for extractive waste facilities 
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The unit price range as listed for site preparation investigations apply as well for envi-
ronmental  monitoring  investigations  that  usually  include  also  sampling  and  different 
types of analytics. 

5.4.2  Site preparation and quality management  

The following tables under table 13 summary include the costs for: 
•  preparation of the site for the planned renovation works 
•  setting up the construction site 
• 

topographical  survey  of  the  actual  state  before  start  of  construction,  surveys 
during construction and surveys after completion of construction  

•  building of construction roads 
•  occupational health and safety and 
•  quality management. 

Table 13: Unit price range for site preparation and quality management 

Site preparation 

Clearance of heavy vegetation from area 
incl. disposing  

Felling trees, trunk diameter 10 – 30 cm, 
incl. disposing 

Preparation of areas for construction site 
equipment, storage spaces and technolog-
ically required areas and removal after 
completion of works 

Description 
Site facilities 

Set up heatable site container (office con-
tainer  and  container  for  the  employees) 
and removal after completion of works 
Operation  of  site  container  (office  con-
tainer and  container for the employees) 
When working in contaminated areas, set 
up  a  black  and  white  plant  and  removal 
after completion of works  
Operation of black and white plant  
Erection  and  clearing  of  a  mobile  tire 
washing  plant  including  costs  for  water 
connection,  consumption  meter,  water 
consumption,  removal  and  orderly  dis-
posal of the wastewater  
Provision  and  operation  of  the  tire  wash-
ing system 
Provision  of  the  site  equipment  in  the 
event  of  construction  interruptions  not 
caused by the contractor 

European Commission  

Unit 

m² 

pc 

m² 

Unit 

Low range 

High range 

[€] 

0.25 

33 

[€] 

0.55 

58.00 

9.60 

21.40 

Low range 
[€] 

High range 
[€] 

lump-sum 

1,543 

2,160 

month 

542 

lump-sum 

month 

3,514 

598 

651 

6,502 

928 

lump-sum 

2,570 

6,425 

week 

week 

319 

29 

574 

77 

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Establishing of all needed media connec-
tions  and    removal  after  the  end  of  con-
struction 
Erection,  provision  and  removal  after 
completion  of  works  of  container  with 
cover (capacity over 10 to 15 m³) for sep-
arate  collection  of  unsuitable  waste  for 
reinstallation,  e.g.  scrap,  hazardous 
waste, etc.. 
Clearing  of  all  machineries,  plants  etc. 
from  the  construction  site.  Preparation  of 
used  areas  and  paths  according  to  the 
original condition or the area planning 

Description 
Topographical survey 

Costs  for  the  first  topographical  survey 
incl. creation of site plans and cross sec-
tions (digital and analog) 
Survey  during  construction,  pegging  out, 
intermediate site plans and cross sections 
(digital and analog) 
Survey  after  the  end  of  construction,  as 
completed drawings (digital and analog) 
Restoration  of  boundary  stones  incl.  ca-
dastral survey 

Description 
Manufacture of temporary roads (to all 
types of facilities to be rehabilitated) 
Construction  of  temporary  roads  (level-
ling,  compacting,  geotextile,  ballast  – 
thickness  0,5  m)  incl.  repair  and  mainte-
nance works 
construction of temporary roads (levelling, 
compacting, geotextile, ballast – thickness 
0,3 m) incl. repair and maintenance works 
Removal of temporary roads after the end 
of construction  
Quality  management 
parameters  

for  geotechnical 

Description 
Health and safety at work 

Development of the regulations for 
health and safety at work 
Safety engineer - Coordinating and moni-
toring  of  compliance  with  regulations  for 
health and safety at work 
Development  of  Occupational  Health  and 
Safety Plan acc. to ISO 45001 
Installation,  maintenance,  operation  and 
removal of overpressure driver cabin with 
filter system 

European Commission  

lump-sum 

1,120 

2,800 

pc 

21 

26 

lump-sum 

840 

1,302 

Unit 

ha 

ha 

ha 

lump-sum 

Low range 
[€] 

High range 
[€] 

600 

180 

806 

390 

1,000 

324 

1,247 

450 

Unit 

Low range 
[€] 

High range 
[€] 

m² 

m² 

m² 

m² 

12.50 

16.30 

8.00 

3.75 

0.08 

10.45 

4.10 

0.12 

Unit 

Low range 
[€] 

High range 
[€] 

pc 

d 

pc 

pc 

990 

2,270 

380.00 

650 

563 

1,826 

1,080 

9,956 

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Provision  of  personal  protective  equip-
ment for work in contaminated areas (de-
pending on the number of workers) 

lump-
sum/employee 

317 

432 

Description 
Site facilities for quality management 

Set up heatable site container (office and 
quality  control  laboratory)  and  removal 
after completion of works 
Operation  of  site  container  (office  and 
quality control laboratory) 

Description 

Unit 

Low range 
[€] 

High range 
[€] 

lump-sum 

2,897 

4,056 

month 

543 

651 

Site facilities for fibreglass 

Unit 

Low range 

High range 

[€] 

[€] 

Delivery of all necessary equipment, set-
ting up the construction site container, 
setting up storage spaces, including re-
moval after completion of works 

Description 

lump-sum 

38,900 

81,850 

Site facilities for installation of ground-
water monitoring wells 

Unit 

Low range 

High range 

[€] 

[€] 

Delivery of all necessary equipment, set-
ting up the construction site container, 
setting up storage spaces, including re-
moval after completion of works 

lump-sum 

4,588 

9,863 

Relocation of drilling equipment 

pc 

41 

651 

5.4.3  Earthworks 

The cost of earthworks depend on the type of operation for profiling and site prepara-
tion  works  (like  excavation,  loading  to  trucks,  area  profiling  with  soil  relocation,  com-
paction,  slope  profiling,  transportation  by  vehicles,  putting  waste  rock),  type  of  equip-
ment (excavators, excavators-dragline, backhoe, dozers, pneumatic trailer-rollers), the 
equipment’s  capacity  and  the  handled  material  (soil  class,  waste  rock).  Dimensional 
elements  (volume,  deployment  distance)  and  work  technology  (layered  deposition, 
slope angles) have to be considered. 

Further  earthworks  are  demolition  works  (demolishing  of  reinforced  concrete  struc-
tures,  excavation  of  solid  reinforced  concrete,  breaking  of  reinforced  concrete  struc-
tures,  arc  welding  when  dismantling  metallic  structure,  demolition  of  the  brick  walls, 
removal of railway tracks  sleepers and ballast, removal of the asphalt paving and sub-
grade, construction garbage profiling, crushing of the demolition material into a trans-
portable  size,  loading/unloading  works  during  transportation),  type  of  equipment,  the 
equipment’s capacity. Dimensional elements (volume, deployment distance) and work 
technology have to be considered. Also, the cost that has to be paid for deposition of 
construction and demolition waste if the case may be. The cost of pavement depends 
on  the  material  used  for  pavement  (crushed  stone,  asphalt-concrete  mixes,  concrete, 

187 

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07.201/2018/793585/ETU/ENV.B.3 

the  materials  can  be  found  and  supplied  from  variable  distances)  and  the  purpose  of 
the pavement. Table 14 illustrates the price range for earth works. Note: waste disposal 
is given in tons because in practice it is usually weighed for performance proof, while 
soil  installation  is  given  m³  because  the  performance  proof  is  usually  based  on  topo-
survey data). 

Table 14: Price range for earth works. 

Description 

Earthworks 
Excavation  of  garbage  from  the  construction 
site, load in provided containers  
Containers loading on trucks and transportation 
of containers, up to 5 km and dumping the gar-
bage 
Removal of waste rock and loading on trucks 
Putting  the  waste  rock;  layered  compaction  by 
dozers 
Excavation of top soil loading and  disposing 
Excavation of soil, liquid to mushy soil type incl. 
loading 
Excavation  of  soil,  light  and  medium heavy soil 
type incl. loading 
Excavation of heavy, soil type to light rock incl. 
loading 
Excavation of heavy rock incl. loading 
Supply and installation of subsoil, installation in 
layers, layer thickness ≤ 0.3 m, D Pr ≥ 92 % 
Supply  and  installation  of  topsoil,  installation  in 
one layer, layer thickness ≥ 0.1 m, without com-
paction 
Delivery of soil for slope profiling, layer by layer, 
layer thickness up to 30 cm 
Delivery and implementation of bentonite for soil 
improvement and  stabilisation 
Delivery  and  implementation  of  lime  for  soil 
stabilisation 
Transportation by vehicles, distance 1 km 
Transportation by vehicles, distance 2 km 
Transportation by vehicles, distance 15 km 
Area profiling with soil relocation to 5 m by doz-
ers 
Area  profiling  with  soil  relocation  to  10  m  by 
dozers 
Soil compaction, layer thickness up to 30 cm 
Deliver  soil  and  layer-by-layer  installation  with 
compaction as surface profiling, layer thickness 
up to 30 cm 
Description 
Quality management 

Geotechnical Parameters 
Delivered filling material 
Relocation material 
Chemical Parameters 
Delivered filling material 

European Commission  

Unit 

Low range 
[€] 

High range 
[€] 

t 

m³ 

m² 
m3 

m³ 

m³ 

m³ 

m³ 

m³ 

m³ 

m³ 

m³ 

m³ 

m³ 

t 
t 
t 

m² 

m² 

m² 

m³ 

Unit 

m³ 
m³ 

m³ 

2.20 

9.45 

0.70 

1.40 

2.55 

10.00 

8.20 

14.75 

83.20 

8.60 

12.25 

15.75 

31.00 

11.80 

5.15 
6.80 
24.60 

1.15 

1.24 

0.55 

13.70 

4.00 

12.75 

3.00 

1.90 

7.35 

18.46 

15.70 

25.60 

128.25 

13.70 

18.40 

30.85 

70.00 

39.00 

9.60 
12.75 
46.05 

3.35 

3.90 

1.00 

24.60 

Low range 
[€] 

High range 
[€] 

0.75 
0.75 

0.05 

0.85 
0.85 

0.10 
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07.201/2018/793585/ETU/ENV.B.3 

Materials removed for disposal 
Radiometric survey 
Spectrometric analyses 

5.4.4  Fencing and Drainage 

m³ 

pc 

0.01 

90.00 

0.05 

220.00 

Cost for fencing should consider supply and placing temporary and definitive fence and 
access  gates.  Typical  fence  for  various  purposes  would  lead  to  specific  material  and 
dimensions.  Foundation  and  earthworks  should  be  included.  The  length  of  the  fence 
and the ease of access would be key elements in the cost value range. Table 15 illus-
trates the unit price range for fencing. 

Cost  for  drainage  should  consider  water  discharge  channels  installation,  open  chan-
nels  at  roadsides,  construction  of  water  discharges  from  longitudinal  drainage  chan-
nels, installation of drainage pipes, installation of precast concrete manhole, installation 
of single-entry water discharge reinforced concrete round culverts under dams.  Table 
16  shows  the  unit  price  range  for  drainage.  For  channels  operation  such  as  manual 
clearing of soil in ditches and construction of reinforced concrete walls and bottom of 
the  channel  will  must  be  considered  case  by  case.  Length  and  typical  cross  section 
would be key elements in the cost value range. The method of supplying the concrete 
and  the  steel  reinforcement  elements  would  have  to be considered when considering 
the cost range.  

Table 15: Unit price range for fencing  

Description  

Fencing 

Securing only for the construction period 

Deliver and install of warning and prohibitions 
signs incl. removal after the end of construction 

Delivery and installation of barrier tape on earth 
spikes (2 pcs / 10 m) incl. removal after the end of 
construction 

Supply and placing building site fence, height 2,0 
m, incl. base stands along editing site boundary 
incl. removal after the end of construction 

Deliver the barrier and install it at the entrance 
including all necessary parts and services. Clear 
width 6 m, incl. concrete foundations and earth-
works incl. Removal after the end of construction 

Keeping and maintenance of security systems 

Permanent securing 
Deliver and install of warning and prohibitions 
signs  
Supply and placing fence, height 1,8 m, incl. con-
crete foundation and earthworks,  
Supply and placing double wing gate, total width 3 
m, incl. concrete foundation and earthworks 

European Commission  

Unit 

Low range 
[€] 

High range 
[€] 

piece 

19.30 

23.20 

m 

m 

0.95 

1.40 

9.60 

17.30 

pc 

1,742 

2,090 

m and 
month 

piece 

m 

pc 

2.20 

2.90 

27.30 

20.20 

2,087 

31.50 

29.30 

3,027 

189 

  
  
  
 
 
 
 
  
  
  
  
  
  
 
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07.201/2018/793585/ETU/ENV.B.3 

Table 16: Unit price range for drainage 

Description 

Drainage 
Construction  of    drainage  channel  without  fas-
tening  (only  soil  excavation,  light  and  medium 
heavy  soil  type),  bottom  width  up  to  0.5  m,  depth 
up to 0.5 m 
Construction of  drainage channel without fas-
tening (only soil excavation, light and medium 
heavy soil type), bottom width up to 1.0 m, depth 
up to  1.0 m 
Fastening of drainage channel with ballast, Layer 
thickness up to 0,2 m 

Fastening of drainage channel with pavement 
Fastening of drainage channel with reinforced con-
crete elements, bottom width 0.5 m, channel thick-
ness up to 0.75 m, slope inclination 1:2 

Securing  inlets  and  outlets  and  embankment  foot 
with hydraulic piles in concrete 

Delivery and installation of a sheet pile 
Installation  of  drainage  pipe,  polyethylene,  d=  300 
m  incl.  pipe  trench  excavation  and  filling,  laying 
depth up to 1.0 m 
Installation  of  drainage  pipe,  polyethylene,  d=  300 
m  incl.  pipe  trench  excavation  and  filling,  laying 
depth up to 2.0 m 
Installation  of  drainage  pipe,  polyethylene,  d=  400 
m  incl.  pipe  trench  excavation  and  filling,  laying 
depth up to 1.0 m 
Installation  of  drainage  pipe,  polyethylene,  d=  400 
m  incl.  pipe  trench  excavation  and  filling,  laying 
depth up to 2.0 m 
Building of pipe culvert under dam, reinforced con-
crete pipe d = 0.5 m, incl. earth works  

Installation  of  precast  concrete  manhole,  d=1.0  m 
and h=1.0 m incl. earth works 

Installation  of  precast  concrete  manhole,  d=1.0  m 
and height up to 2.0 m incl. earth works  

Unit 

Low range 

High range 

[€] 

[€] 

m³ 

7.70 

10.10 

m³ 

m² 

m² 

m 

m 

m² 

m 

m 

m 

m 

m 

pc 

pc 

8.10 

11.30 

1.05 

8.10 

225 

111 

252 

120 

133 

165 

175 

1548 

908 

1,385 

1.90 

11.30 

292 

144 

453 

173 

193 

239 

254 

2,245 

1,362 

2,078 

5.4.5  Demolition / Decommissioning 

Demolition  of  constructions  developed  at  ground  level  or  buried  may  include:  road 
clothing, industrial platforms, bunkers, underground galleries, pipelines, etc. Demolition 
works  include  also  scaffolding  and  housing  of  buildings  to  be  demolished.  Table  17 
illustrates the unit price range for demolition / decommissioning. 

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Table 17: Unit price range for demolition / decommissioning 

Description 

Demolition / Decommissioning 

Demolishing of reinforced concrete structures by 
hydraulic hammer  

Construction garbage profiling,  

Loading/unloading works during transportation. 
large parts of prefabricated reinforced concrete 
with mass up to 3 t: unloading  

Breaking of reinforced concrete structures of 
reservoir and other concrete facilities by hydrau-
lic hammer 

Arc welding when dismantling metallic structure 

Loading/unloading works during transportation. 
steel works with mass up to 1 t: unloading  

Demolition of the brick walls (buildings) 

Demolition of larger buildings  

Removal of railway tracks, cleaning of material 
for reutilisation, evacuation 

Removal of railway sleepers, transport to the 
foreseen storage area, unload - storage area, TD 
up to 15 km 

Removal of railway ballast, load on, transport to 
the storage area, unload - storage area, TD up to 
15 km 

Dismantling of concrete / reinforced concrete 
single foundations and walls incl. crushing into a 
transportable size, load on, transport to the stor-
age area, unload - storage area, TD up to 15 km 

Demolition of concrete channels, crushing of the 
demolition material,  load on, transport to the 
storage area, unload - storage area, TD up to 15 
km 

Demolition of smaller disjointed reinforced areas, 
crushing of the demolition material,  load on, 
transport to the storage area, unload - storage 
area, TD up to 15 km 

Unit 

m3 

m3 

t 

m3 

t 

t 

m3 
m³ building 
volume 

m 

pc 

m³ 

m³ 

Low range 

High range 

[€] 

434 

1.90 

[€] 

608 

3.00 

32.45 

51.90 

418 

635 

69 

26.80 

60.00 

10.00 

628 

889 

90 

41.55 

93.10 

45.50 

5.00 

7.75 

17.20 

23.20 

50.10 

72.65 

m 

10.50 

16.30 

m² 

19.80 

30.70 

Quality management 

Unit 

Low range 
[€] 

High range 
[€] 

Chemical parameters for disposal 

Spectrometric analyses 

m³ 

pc 

0.05 

90.00 

European Commission  

0.15 

220.00 

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5.4.6  Filling 

The  cost  of  fill  also  depends  on  the  dimension  and  location  (the  distance  from  the 
source of filling material, ways of access) of the type of mining element that requires fill 
(ditches,  pockets  of  pits  and  holes,  sinkholes,  trenches  and  pits)  the  type  of  used 
equipment and its capacity also the class of filling material (soil, waste rock). The cost 
of  operations  that  consume  liquid  concrete  for  filling  must  take  into  consideration  the 
method of supplying the concrete when considering the cost range. Table 18 shows the 
unit price range for filling. 

Table 18: Unit price range for filling 

Description 

Filling 
Layer-by-layer installation of compactable over-
burden, located at the construction site,  for the 
pit filling, installation according to project speci-
fications, layer thickness up to 0.3 m 
Delivery  and  layer-by-layer  installation  of  recy-
cled  material  (brick  and  concrete  breakage)  for 
the  pit  filling,  installation  according  to  project 
specifications, layer thickness up to 0.3 m 
Delivery  and  layer-by-layer  installation  of  com-
pactable  soil  for  the  pit  filling,  installation  ac-
cording to project specifications, layer thickness 
up to 0.3 m 
Layer-by-layer installation of compactable over-
burden, located at the construction site,  for the 
slope  stability,  installation  according  to  project 
specifications, layer thickness up to 0.3 m 
Delivery  and  layer-by-layer  installation  of  recy-
cled  material  (brick  and  concrete  breakage)  for 
the  slope  stability,  installation  according  to  pro-
ject specifications, layer thickness up to 0.3 m 
Delivery  and  layer-by-layer  installation  of  com-
pactable  soil  for  the  slope  stability,  installation 
according  to  project  specifications,  layer  thick-
ness up to 0.3 m 

Unit 

Low range 
[€] 

High range 
[€] 

m³ 

m³ 

m³ 

m³ 

m³ 

m³ 

1.90 

4.05 

6.30 

11.65 

13.70 

24.60 

3.81 

9.25 

8.20 

16.85 

15.75 

30.85 

Quality management 

Unit 

Geotechnical parameters 

Delivered filling material (soil and RC-Material) 

Relocation material 

Soil mechanical Investigation  

Soil mechanic lab investigation  

Chemical Investigation 

GC-MS Screening 

European Commission  

m³ 

m³ 

pc 

pc 

Low range 

High range 

[€] 

0.75 

0.75 

[€] 

0.85 

0.85 

150 

400 

90 

220 

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07.201/2018/793585/ETU/ENV.B.3 

Radiometric Investigation 

Spectrometric analyses 

Chemical Parameters 

Delivered filling material 

Materials removed for disposal 

5.4.7  Relocation 

pc 

m³ 

m³ 

90 

0.05 

0.05 

220 

0.10 

0.15 

Relocation activities are part of the earthworks. The unit price range in included in table 
14. 

5.4.8  Hydraulic and Geochemical Water Protection Options 

Diaphragm  walls  are  walls  made  of  concrete  or  reinforced  concrete,  which  are  either 
concreted in liquid-supported earth slots using the contractor method or manufactured 
by  hanging  precast  concrete  elements  (prefabricated  slot  wall).  Diaphragm  walls  can 
be made to great depths (100 m) and nominal thicknesses from 0.45 m to 1.50 m. Ta-
ble  19  illustrates  the  unit  price  range  for  hydraulic  and  geochemical  water  protection 
options. 

Table 19: Unit price range for hydraulic and geochemical water protection options 

Description 

Diaphragm walls 

Seepage control screen construction made of 
geodiaphragm onto dam surface  

Concrete nails for geodiaphragm 

Description 

Permeable Reactive Barriers / Reactive walls    

Construction of reactive wall 

Filling of reactive wall: zero valent iron 

Filling of reactive wall: organic material 

Description 

Funnel and gate 

Construction of funnel and gate 

Filling of funnel and gate: zero valent iron 

Unit 

m² 

pc 

Unit 

m² 

t 

t 

Unit 

m² 

t 

European Commission  

Low range 

High range 

[€] 

198 

16.50 

[€] 

250 

21 

Low range 

High range 

[€] 

200 

286 

20 

[€] 

300 

440 

30 

Low range 

High range 

[€] 

200 

292 

[€] 

300 

664 

193 

  
  
  
  
  
  
 
  
  
  
 
  
  
 
  
  
  
 
 
 
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financial guarantee for extractive waste facilities 
07.201/2018/793585/ETU/ENV.B.3 

Description 

Groundwater treatment – ISCO system  (≤ 10 
wells, injection performance 0,5 - 5 m³/h, 
Fenton's reagent or permanganate) 

Unit 

Low range 

High range 

[€] 

[€] 

Construction of well gallery and injection system  

pc 

Operation of injection system 

monthly 

Demolition of well gallery and injection system  

pc 

8,500 

9,000 

6,000 

9,000 

10,000 

7,000 

Description 

Anoxic Limestone Drains / Reducing and 
Alkalinity Producing Systems (RAPS) in 
shafts and adits 

Construction drainage trench 

Delivery of alkaline material as buffer  

Description 

Constructed wetland 

Construction of pond structure, 100m³ pond 
volume, including liner (cost depending from 
liner type) 

Installation of inlet and outlet structures 

Planting cost (depending on planting methodol-
ogy and type of plants) 

Unit 

Low range 

High range 

[€] 

[€] 

m 

m³ 

Unit 

pc 

m 

ha 

25 

15 

28 

30 

Low range 

High range 

[€] 

[€] 

2,500 

25 

2,000 

4,000 

75 

3,500 

5.4.9  Shaft and adit closure 

Table 20 shows the unit price range for shaft closure, table 21 for adit closure. The cost 
of shaft closure depends on the dimension and location (the distance from the source 
of  filling  material,  ways  of  access)  and  the  proposed  closing  technology  (in  terms  of 
filling or only capping with a reinforced concrete slab including ways to handle the con-
crete handling, manual preparation on site or by using a mobile concrete pump) that is 
depending on the bedrock surrounding the shaft. The method of supplying the concrete 
and  the  steel  reinforcement  elements  would  have  to be considered when considering 
the cost range. The cost of added closure depends on the dimension and location (the 
distance from the source of filling material, ways of access) and the proposed closing 
technology  (in  terms  of  filling  or  only  capping  with  a  reinforced  concrete  slab)  that  is 
depending on the bedrock surrounding the shaft. Costs are very site specific due to the 
particular setting of each location. 

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financial guarantee for extractive waste facilities 
07.201/2018/793585/ETU/ENV.B.3 

Table 20: Unit price range for shaft closure 

Description 

Shaft closure 

Delivery of and filling with crushed rock, Shaft 
filling 

Delivery of and filling with debris, Shaft filling 

Reinforced concrete slab installation (with mo-
bile concrete pump)  

Concrete bedding preparation, concrete B 7,5 

Install reinforced concrete slab; 

reinforcing 70 kg/m³ 

Unit 

m3 

m3 

m³ 

m3 

m³ 

Low range 

High range 

[€] 

45 

20 

178 

75 

180 

[€] 

100 

60 

250 

120 

245 

Table 21: Unit price range for adit closure 

Description 

Unit 

Adit closure 
Construction of shallow ditch in adit bottom, 
incl. earth works 
Construction concrete strip foundation 

Construction of brick wall (single sections) 

into  sides  by  air-

Installation  of  drainage  pipe,  polyethylene, 
d= 200 mm  incl. earth works 
Cuts  construction 
hammers 
Seepage control screen construction made 
of geodiaphragm onto dam surface  
Concrete nails for geodiaphragm 
Protective covering with stones of the drain 
pipe, stone size - 200 mm  
Liquid  concrete  filling  of  adit  (by  mobile 
concrete pump)  
Beam  elements  installation  to  compensate 
uplift  
Contouring works at adit portal 

m 

m3 

m³ 

m 

m3 

m² 

pc 

m3 

m³ 

m³ 

m³ 

Low range 

High range 

[€] 

120 

140 

129 

133 

330 

198 

16 

33 

129 

513 

104 

[€] 

152 

204 

187 

150 

413 

250 

21 

40 

174 

600 

130 

5.4.10  TMF Dewatering and Closure 

Cost  of  TMF  Dewatering  and  Closure  depend  on  size  and  settlement  status  of  the 
TMF. The TMF sediments that are more settled while lead to a shorter dewatering time 
span and shorten the closure time. TMFs that are needed to be closed through vertical 
drains  and  fostered  rock  stabilisation  need  additional  closure  activities.  Note:  prices 
quoted in table 22 include all necessary earthworks. Drainage layer material must con-

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financial guarantee for extractive waste facilities 
07.201/2018/793585/ETU/ENV.B.3 

sist  of  quality  proven  material  that  must  also  meet  particular  chemical  requirements, 
depending on water to be drained. Quality certificates are required here (in-house and 
third-party  testing)  and,  if  necessary,  an  extraction  location  far  away.  Table  22  illus-
trates the unit price range for TMF dewatering and closure. 

Table 22: Unit price range for TMF dewatering and closure  

Description 

TMF Dewatering and Closure 

Delivery and installation of a gravel base  

Delivery and laying of excavator mats incl. 
transport 

Delivery and installation of geotextile incl. quali-
ty management 

Delivery and installation of geo-grids incl. quali-
ty management 

Delivery and installation of drain mats incl. qual-
ity management 

Pressing in the vertical drainage (geotextile 
strips) 

Delivery and installation of a drainage layer 
(gravel 16/32) 

Delivery and installation of a  precast concrete 
manhole as pumping shaft, d=1.0 m and hight 
up to 2.0 m incl. earth works  

Delivery and installation of a pump 

Delivery and installation of a pressure pipe 
PEHD ND 80 

Delivery and installation of a pressure pipe 
PEHD ND 100 

Delivery and installation of a mineral soil 

Delivery and installation of a RCL-material 

Installation of groundwater monitoring wells 

Operating costs for pumps 

Description 

Quality management 

Geotechnical parameters 

Bearing capacity of sludge (field torvane test) 

Mineral soil and RCL-material 

Drainage gravel  

Radiometric survey 

Spectrometric analyses 

European Commission  

Unit 

Low range 

High range 

[€] 

[€] 

m³ 

m² 

m² 

m² 

m² 

m 

m³ 

pc 

pc 

m 

m 

m³ 

m³ 

m 

h 

Unit 

m 

m³ 

m³ 

pc 

25.75 

8.35 

3.80 

7.25 

7.80 

3.30 

62.45 

41.20 

13.50 

5.00 

11.60 

12.45 

6.50 

99.90 

1,385.35 

2,078.00 

1,837.00 

2,663.00 

29.10 

53.20 

13.70 

6.30 

74.80 

5.00 

39.30 

71.85 

24.60 

11.65 

462.00 

15.00 

Low range 

High range 

[€] 

15 

0.75 

0.75 

90 

[€] 

25 

0.85 

0.85 

220 

196 

  
  
  
 
  
  
  
  
  
  
  
  
  
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Chemical Parameters 

Mineral soil and RCL-material 

Drainage gravel 

m³ 

m³ 

0.05 

0.05 

0.10 

0.10 

5.4.11  Application of Surface Sealing 

Table 23 shows the unit price range for the application of surface sealing. Cost of ap-
plication  of  surface  sealing  depend  on  the  surface  to  be  sealed  dimensions  (surface, 
position)  location  (the  distance  from  the  source  of  materials  to  be  used  for  sealing) 
ways of access and the proposed sealing technology that will give the materials char-
acteristics  (clay  type,  soil  type,  geogrids,  geomembranes,  geotextile,  gravel-grit-
crushed sand-mix with specific grain size) the equipment that should be used (dozers, 
sheepsfoot roller, compactors) and the volume of the sealing layers (layer thickness) if 
applicable.  

Table 23: Unit price range for the application of surface sealing 

Description 

Application of surface sealing 

Bearing and compensation layer 

Fine profiling of the surface of the filling accord-
ing to the project by dozer with material reloca-
tion up to 5 m (overburden) incl.  compaction 
Fine profiling of the surface of the filling accord-
ing to the project by dozer with material reloca-
tion up to 5 m (recycled material) incl. compac-
tion 

Fine profiling of the surface of the filling accord-
ing to the project by dozer with material reloca-
tion up to 5 m (soil) incl.  compaction 

Delivery  and  installation  of  a  bearing and com-
pensation layer made of suitable waste material 
including  compression,  layer  thickness    0.3  m, 
D Pr ≥ 95 % Kf = 1 x 10 -4 m/s 

Delivery  and  installation  of  a  bearing and com-
pensation layer made of suitable recycled mate-
rial  including  compression,  layer  thickness    0.3 
m, D Pr ≥ 95 % Kf = 1 x 10 -4 m/s 

Delivery  and  installation  of  a  bearing and com-
pensation layer made of suitable soil  including 
compression, layer thickness  0.3 m, D Pr ≥ 95 
% Kf = 1 x 10 -4 m/s 

Mineral sealing layer 

Supply and installation of cohesive soil as seal-
ing  layer,  installation  in  2  layers  with  compac-
tion,  layer  thickness    0.25  m,  D  Pr  ≥  95  %  
Kf < 5 

 10-9 m/s 

Capillary barrier 

⋅

European Commission  

Unit 

Low range 

High range 

[€] 

[€] 

m² 

m² 

m² 

m³ 

1.40 

4.00 

1.45 

4.20 

1.40 

4.00 

2.20 

4.65 

m³ 

11.65 

13.40 

m³ 

15.75 

28.30 

m³ 

52.40 

70.70 

197 

  
  
  
 
  
  
  
  
  
  
  
  
  
  
  
  
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Supply  and  installation  of  gravel  as  capillary 
block, layer thickness 0.25 m, D Pr ≥ 92 %  
Supply and installation of sand as capillary lay-
er, layer thickness 0.4 m, D Pr ≥ 92 %  
Revegetation layers 

Supply and installation of subsoil, installation in 
layers, layer thickness ≤ 0.3 m, D Pr ≥ 92 % 

Supply  and  installation  of  topsoil,  installation  in 
one  layer,  layer  thickness  ≥  0.1  m,  without 
compaction 

Additional  compaction  of  topsoil  layer  with 
sheepsfoot roller 

Geosynthetics 

Creation of an installation and applying concept 
for the geosynthetics 

Supply  and  installation  of  geogrid  incl.  quality   
management  

Supply  and  installation  of  drainage  mats  incl. 
quality management  

Supply  and  installation  of  synthetic  geomem-
brane incl. quality management 
Supply and installation of geotextiles incl. quali-
ty management 

Tektoseal 

Design  of  an  installation  and  applying  concept 
for tektoseal 

Supply  and  installation  of  tektoseal  incl.  quality 
management  

Supply  and  installation  of  drainage  mats  incl. 
quality management  

Supply and installation of geotextiles incl. quali-
ty management  

Bentonite mat 

Design  of  an  installation  and  applying  concept 
for bentonite mat  

Supply  and  installation  of  bentonite  mat  incl. 
quality management  

Supply  and  installation  of  drainage  mats  incl. 
quality management 

Supply and installation of geotextiles incl. quali-
ty management  

Bitumen / asphalt sealing 

Design  of  an  installation  and  applying  concept 
for asphalt sealing (m²) 

European Commission  

m² 

m² 

m³ 

m³ 

m² 

m² 

m² 

m² 

m² 

m² 

m² 

m² 

m² 

m² 

m² 

m² 

m² 

m² 

m² 

13.30 

25.90 

17.90 

34.90 

8.60 

13.70 

12.25 

18.40 

0.35 

0.50 

0.35 

7.25 

7.80 

14.50 

0.65 

11.60 

12.45 

24.70 

3.80 

5.00 

0.35 

15.20 

7.80 

2.80 

0.35 

6.90 

7.80 

3.80 

0.65 

37.30 

12.45 

5.00 

0.65 

12.30 

12.45 

5.00 

0.25 

0.50 

198 

  
  
  
  
  
  
 
 
 
 
 
 
 
 
 
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Supply  and  installation  of  drainage  mats  incl. 
quality management (m²) 

Supply  and  installation  of  asphalt  sealing  layer 
incl.  quality  management  (m²),  asphalt  sealing 
layer, 4 cm 

Supply  and  installation  of asphalt sealing bear-
ing incl. quality management (m²), asphalt bear-
ing layer, 6cm 

m² 

m² 

m² 

Description 

Unit 

Geotechnical Parameters 

Filling material 

Levelling course and bearing layer 

Sealing layer 

Subsoil 

topsoil 

Capillary Block 

Capillary layer 

Chemical Parameters 

Filling material 

Levelling course and bearing layer 

Sealing layer 

Subsoil 

topsoil 

Capillary Block 

Capillary layer 

Radiometric survey  

Spectrometric analyses 

Test field 

Test field for the surface sealing system  

Geotechnical quality tests 

Chemical quality tests 

Tests for geosynthetics 

m³ 

m² 

m² 

m² 

m² 

m² 

m² 

m³ 

m² 

m² 

m² 

m² 

m² 

m² 

pc 

pc 

lump-sum 

lump-sum 

lump-sum 

7.80 

7.65 

12.45 

17.30 

5.90 

7.70 

Low range 

High range 

[€] 

0.05 

0.20 

1.00 

0.35 

0.40 

1.00 

1.00 

0.01 

0.01 

0.01 

0.25 

0.15 

0.01 

0.01 

90 

[€] 

0.15 

0.25 

3.50 

0.45 

0.50 

3.50 

3.50 

0.05 

0.05 

0.05 

0.35 

0.25 

0.05 

0.05 

220 

28,690 

13,000 

2,800 

1,000 

34,500 

15,500 

3,350 

1,200 

5.4.12  Reclamation / Revegetation 

The  cost  of  reclamation  depends  on  the  after  closure  foreseen  usage  of  surface  that 
would be subject for reclamation. Usually involves the cost related to prepare the soil 
cover  for  seeding,  spread  fertilizers,  seeding  of  the  selected  plants  and  also  mainte-
nance activities such as trimming and watering. Table 24 illustrates the unit price range 
for reclamation / revegetation (note: pc refers to piece, e.g. per each planted shrub). 

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Table 24: Unit price range for reclamation / revegetation 

Description 

Reclamation 

Supply and installation erosion protection mats 

Sowing with grass seed onto surface sealing 
incl. first fertilization and irrigation 

Repair damages from erosion (lawn): Loosen 
the topsoil, eliminate unevenness with topsoil 
(to be livered) and sowing grass seed, first ferti-
lization and irrigation 
Supply and planting shrubs incl. first fertilization 
and irrigation 

Supply and planting trees incl. first fertilization 
and irrigation 

Maintenance of grass seed (cutting, fertilization, 
irrigation) 

Maintenance of planted shrubs (fertilization, 
irrigation, pruning) 

Maintenance of planted trees (fertilization, irri-
gation, pruning) 

Unit 

m² 

m² 

m² 

pc 

pc 

m² 

pc 

pc 

Low range 

High range 

[€] 

2.50 

0.35 

0.45 

6.35 

[€] 

3.30 

0.50 

0.65 

7.60 

151.10 

181.30 

0.80 

0.90 

1.00 

1.10 

15.60 

19.50 

5.4.13  Flooding and Water Treatment 

Usually flooding happens by stopping the extraction of water through pumping so there 
is no related cost. This operation is related to underground mines and for some open 
pits.  However,  flooder  might  require  flooding  water  management.  Table  25  illustrates 
the unit price range for flooding and water treatment. 

Table 25: Unit price range for flooding and water treatment 

Low range 

High range 

Description 

Flooding 

Delivery and installation of waterproof clay 

Filling and sealing of boreholes 

Erection of embanked drainage ditches includ-
ing filling with limestone gravel, cross-section 
area up to 1.0 m² 
Erection of channels from concrete channel 
elements including filling with limestone gravel, 
cross-section area up to 1.0 m² 
Erection of a water treatment plant 

Construction water passive water treatment 
Deposit of immobilized products at the site 

Disposal of immobilized waste 

Disposal of immobilized hazardous waste 

European Commission  

Unit 

m³ 

m 

m 

m 

[€] 

80 

6.00 

27 

250 

Lump sum 

Lump sum 
m³ 

t 

t 

1.5 mill 

300,000 
5 

50 

100 

[€] 

140 

11 

34 

320 

7.0 mill 

1.0 mill 
7.50 

75 

850 

200 

  
  
  
 
  
  
  
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Operation of a water treatment plant 

Operation of a passive water treatment setting 

m³ 

m³ 

8 

3 

15 

10 

5.4.14  Water treatment  

Water treatment is typically needed at each mine site, however unit cost is not possible 
to be provided for that item because the setting and dimension of the treatment meth-
odology is particularly site specific. Beside the investment cost, the operational costs of 
a water treatment facility accumulate on the long term. In table 26 are given the elec-
tricity prices in Europe. 

Table 26: European Electricity prices (source: https://strom-report.de/electricity-prices-
europe/) 

5.4.15  Waste disposal 

Cost  related  to  waste  that  is  shipped  outside  of  the  mine  site  (construction  related 
wastes, garbage, special waste) that is subject for closure in order to be deposited in 
201 

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financial guarantee for extractive waste facilities 
07.201/2018/793585/ETU/ENV.B.3 

waste  management  facilities  that  belong  to  third  parties  will  be  due  to  load-
ing/unloading works during transportation by vehicles and the fee/ton as storage tax. 

Table 27: Unit price range for waste disposal 

Description 

Waste disposal 
Loading/unloading works during transportation 
by vehicles. Construction related 
wastes/garbage with loading by excavators 

Unit 

t 

Low range 

High range 

[€] 

14. 

[€] 

18 

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for the calculation and the periodic adjustment of the 
financial guarantee for extractive waste facilities 
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Annex 1  

Correlation  between  the  annex  of  the  EIA  Directive  with  the  formalities  of  the 
codes  of  the  Statistical  Classification  of  Economic  Activities  in  the  European 
Community (commonly referred to as NACE). 

EIA  ANNEX  II  list  “shall  deter-
mine  whether  the  project  shall 
be  made  subject  to  an  assess-
ment” (Medium Risk) 

EIA  ANNEX  I  list  “shall 
be  made  subject  to  an 
(High 
assessment” 
Risk) 

NACE/  
ISIC 
code 

List of all industrial 
activities 
if  not 
subject 
for  any  of  EIA 
ANNEX  I  or  II  lists 
(Low risk) 
0510  Mining of hard coal 

0520  Mining of lignite 

0610 

Extraction  of  crude 
petroleum 

(2)  EXTRACTIVE 
INDUSTRY(a) 
Quarries,  open-cast  mining  (pro-
jects not included in EIA List 1) (b) 
Underground  mining  (e)  Surface 
industrial  installations  for  the  ex-
traction of coal, 
(2)  EXTRACTIVE 
INDUSTRY(a) 
Quarries,  open-cast  mining  (pro-
jects not included in EIA List 1) (e) 
Surface  industrial  installations  for 
the extraction of coal, 
(2)  (e)  Surface  industrial  installa-
tions  for  the  extraction  of  petrole-
um,  

0620 

Extraction  of  natural 
gas 

(2)  (e)  Surface  industrial  installa-
tions  for  the  extraction  of  natural 
gas,  

0710  Mining of iron ores 

0721  Mining  of  uranium 

and thorium ores 

0729  Mining  of  other  non-

ferrous metal ores 

(2)  EXTRACTIVE 
INDUSTRY(a) 
Quarries,  open-cast  mining  (pro-
jects not included in EIA List 1) (b) 
Underground  mining  (e)  Surface 
industrial  installations  for  the  ex-
traction of ores 
INDUSTRY(a) 
(2)  EXTRACTIVE 
Quarries,  open-cast  mining  (pro-
jects not included in EIA List 1) (b) 
Underground  mining  (e)  Surface 
industrial  installations  for  the  ex-
traction of ores 
(2)  EXTRACTIVE 
INDUSTRY(a) 
Quarries,  open-cast  mining  (pro-
jects not included in EIA List 1) (b) 
Underground  mining  (e)  Surface 
industrial  installations  for  the  ex-
traction of ores 

European Commission  

Quarries  and  open-cast 
mining where the surface 
of  the  site  exceeds  25 
hectares 

(14)  Extraction  of  petro-
commercial 
leum 
for 
purposes  where 
the 
amount  extracted  ex-
ceeds 500 tones/day 
(14) Extraction of natural 
gas  for  commercial  pur-
poses where the amount 
extracted  exceeds  500 
000 cubic meters/day 
(19)  Quarries  and  open-
cast  mining  where  the 
surface  of  the  site  ex-
ceeds 25 hectares 

(19)  Quarries  and  open-
cast  mining  where  the 
surface  of  the  site  ex-
ceeds 25 hectares 

(19)  Quarries  and  open-
cast  mining  where  the 
surface  of  the  site  ex-
ceeds 25 hectares 

211 

 
 
  
Study on the elaboration of guidance on best practices 
for the calculation and the periodic adjustment of the 
financial guarantee for extractive waste facilities 
07.201/2018/793585/ETU/ENV.B.3 

0810 

Quarrying  of  stone, 
sand and clay 

(2)  EXTRACTIVE 
INDUSTRY(a) 
Quarries,  open-cast  mining  (pro-
jects not included in EIA List 1) 

0891  Mining  of  chemical 
and  fertilizer  miner-
als 

0892 

Extraction of peat 

(2)  EXTRACTIVE 
INDUSTRY(a) 
Quarries,  open-cast  mining  (pro-
jects not included in EIA List 1) (b) 
Underground mining  
(2) (a) Peat extraction (projects not 
included in EIA list 1) 

(19)  Quarries  and  open-
cast  mining  where  the 
surface  of  the  site  ex-
ceeds 25 hectares 
(19)  Quarries  and  open-
cast  mining  where  the 
surface  of  the  site  ex-
ceeds 25 hectares 
(19) 
extraction, 
peat 
where  the  surface  of  the 
site  exceeds  150  hec-
tares 

(2)  EXTRACTIVE 
INDUSTRY(a) 
Quarries,  open-cast  mining  (pro-
jects not included in EIA List 1) (b) 
Underground  mining  (e)  Surface 
industrial  installations  for  the  ex-
traction of bituminous shale 
(2)  EXTRACTIVE 
INDUSTRY(a) 
Quarries,  open-cast  mining  (pro-
jects not included in EIA List 1) (b) 
Underground mining  

(19)  Quarries  and  open-
cast  mining  where  the 
surface  of  the  site  ex-
ceeds  25  hectares  and 
(5)  Installations  for  the 
extraction of asbestos 
(19)  Quarries  and  open-
cast  mining  where  the 
surface  of  the  site  ex-
ceeds 25 hectares 

INDUSTRY(a) 
(2)  EXTRACTIVE 
Quarries,  open-cast  mining  (pro-
jects not included in EIA List 1) (c) 
Extraction of minerals by marine or 
fluvial dredging; 

(19)  Quarries  and  open-
cast  mining  where  the 
surface  of  the  site  ex-
ceeds 25 hectares 

0893 
0893 
0899 

Extraction of salt 
Extraction of salt 
Other  mining  and 
quarrying n.e.c. 

811 

812 

0910 

0990 

Quarrying  of  orna-
mental and building 
stone, 
limestone, 
gypsum,  chalk  and 
slate  
Operation  of  gravel 
and  sand  pits;  min-
ing 
of clays and kaolin 

Support  activities  for 
petroleum and  
natural  gas  extrac-
tion 
Support  activities  for 
other mining and 
quarrying 

2399  Manufacture of other 
non-metallic mineral 
products n.e.c. 

(5)  (e)  Installations  for  smelting 
mineral  substances  including  the 
production  of  mineral  fibers  (11) 
(g)  Installations  for  the  manufac-
ture of artificial mineral fibers 

5210  Warehousing 

and 

storage 

(3)  (c)  Surface  storage  of  natural 
gas;(d)  Underground  storage  of 
combustible  gases;(e)  Surface 
storage  of  fossil  fuels;  (11)  (e) 

European Commission  

(5)  Installations  for  the 
processing  and 
trans-
formation  of  asbestos 
and  products  containing 
asbestos  for  friction  ma-
terial,  with  an  annual 
production  of  more  than 
50  tons  of  finished  prod-
ucts  and  for  other  uses 
of asbestos, utilization of 
more  than  200  tons  per 
year. 
for 
Installations 
(21) 
storage  of  petroleum, 
petrochemical,  or  chemi-
cal  products  with  a  ca-

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financial guarantee for extractive waste facilities 
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3821 

Treatment  and  dis-
posal 
non-
of 
hazardous waste  

Storage  of  scrap  iron,  including 
scrap vehicles 
(b)  Installations  for  the  disposal  of 
waste  (projects  not  included  in 
Annex I);(g) Dams and other instal-
lations  designed  to  hold  water  or 
store  it  on  a  long-term  basis  (pro-
jects  not  included  in  Annex  I);(d) 
Sludge-deposition sites; 

Treatment  and  dis-
posal  of  hazardous 
waste 

3822 
383 

39 

36 

Materials recovery 
Rehabilitation  activi-
ties and other  
waste  management 
services 
collection, 
Water 
treatment  and  sup-
ply 

(d) Sludge-deposition sites; 

(c)  Waste-water  treatment  plants 
(projects not included in Annex I); 

I 

pacity  of  200  000  tones 
or more. 
10.  Waste  disposal  in-
stallations  for  the  incin-
eration 
chemical 
or 
treatment  as  defined  in 
Annex 
to  Directive 
2008/98/EC  under  head-
ing D9 of non-hazardous 
waste  with  a  capacity 
exceeding  100  tons  per 
day. 
(iv)  solely  for  the  final 
disposal  of  radioactive 
waste; 9. Waste disposal 
installations  for  the  in-
cineration, 
chemical 
treatment  as  defined  in 
Annex 
to  Directive 
2008/98/EC  of  the  Euro-
pean  Parliament  and  of 
the  Council  of  19  No-
vember  2008  on  waste  ( 
3 ) under heading D9, or 
hazardous 
landfill 
of 
in 
waste,  as  defined 
point 2 of Article 3 of that 
Directive. 

I 

European Commission  

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for the calculation and the periodic adjustment of the 
financial guarantee for extractive waste facilities 
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Annex 2  

Sample of a report structure for Environmental Impact Assessment of mine clo-
sure projects 

1 

1.1 

1.2 

INTRODUCTION 

Background 

Regulatory basis for the Environmental Impact Assessment 

1.2.1  European regulatory framework 

1.2.2  National regulatory framework 

1.3 

1.4 

1.5 

2 

2.1 

2.2 

2.3 

2.4 

2.5 

3 

Previous activities and reports 

Technical scope of this project 

Objectives of the EIA process 

OVERVIEW OF PROPOSED WORKS 

Identified mining legacy objects  

Justification of remedial actions 

Proposed rehabilitation works 

Generalised of types of proposed rehabilitation works 

Timeline of the proposed works 

ENVIRONMENTAL AND SOCIAL BASELINE 

ASSESSMENT  OF  POTENTIAL 

4 
MITIGATION  MEASURES 

IMPACTS  AND 

IDENTIFICATION  OF 

4.1  Methodology  for  the  assessment  of  environmental  impacts  of  rehabilitation 
measures 

4.2 

4.3 

4.4 

4.5 

4.6 

5 

Development of mitigation measures 

Group A: Simple civil works, no major movements of contaminated material 

Group B: Demolition of former processing facilities and burial of debris 

Preferred remedial options per object and potential impacts 

Summary of the results of air quality and noise impact models 

ALTERNATIVE OPTIONS CONSIDERED 

ASSESSMENT  OF  THE  EXPECTED  ENVIRONMENTAL  SITUATION  AFTER 

6 
THE   PROPOSED REHABILITATION WORKS 

7 

8 

CONCLUSIONS 

ENVIRONMENTAL IMPACT STATEMENT, NON-TECHNICAL SUMMARY 

8.1 

Introduction 

European Commission  

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financial guarantee for extractive waste facilities 
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8.2 
EIA 

8.3 

8.4 

Contact  details  of  the  project  proponent  and  of  the  organisation  implementing 

Justification of the proposed project 

Description of the proposed project and alternative options 

Analysis  of  the  proposed  work  methods  with  regard  to  their  compliance  with 

8.5 
best available  techniques (BAT) 

8.6 

8.7 

Description of the existing environmental situation 

Assessment of the proposed project activities 

Assessment of the expected environmental situation after the proposed rehabili-

8.8 
tation works 

8.9  Mitigation measures 

8.10  Proposed monitoring programme 

8.11 

Involvement of the public 

8.12  Evaluation of the acceptability of the impacts on the environment 

9 

REFERENCES 

European Commission  

215