Mining Waste Directive - Risk Assessment requirements

Transcription

1 Mining Waste Directive - Risk Assessment requirements Jörg Frauenstein Federal Environment Agency (UBA) Dessau-Roßlau

2 Recommendations for a Risk Based Inventory of closed / abandoned waste facilities Scope of Article 20 Directive 2006/21/EC Cause serious negative environmental impacts or Have the potential of becoming in the medium or short term a serious threat to human health or the environment. What is serious? No definition of serious, but same wording as the Definition of major accident. Assumption: serious, if impact or potential of impact has a dimension to the degree in case of a major accident

3 Closed / abandoned Mining Location Does the Location include a waste facility? (Heap, Dump; Tailing Pond) Dangerous substances yes no yes Are dangerous substances and hazardous waste expected? (e.g. processing; tailings) Single case evaluation yes yes no Physical stability no Are any historical accidents known? no Is the stability of the facility verified? no Are there any other facts known that will effect the stability? no Is the volume of the tailing > m³? 1 yes Is the height of the heap >10 m? 2 yes Are the following criteria s for heaps fulfilled? 2 Height slope Angel < 20 m 1:2 27 <30 m 1:3 18 <40 m 1:4 14 yes no no yes Not relevant for the inventory 1 based on the irish proposal (ad-hoc Group, 4/2008); 2 based on the Saxonian mining ordinance

4 Criteria for risk based asessment to establish the inventory of abandonend/closed mining waste facilties In acoordance with art. 20 of the directive for abandonend/closed mining waste facilities shall be included in the inventory if the actual status leads to serious negative environmental impacts and relevants threats to human health. The risk assessment should be carried out taking into account annex III first intent of directive ( 2006/21/EC) Non negligible potential for loss of life; Serious danger to human health; Serious danger to the environment and Commission decision 2009/337/EC, especially regarding the source-pathway-receptor chain and the following criteria set out in art.5+6 of the Commission decision. The risk based assessment for the inventory should include also the substance related components.

5 Risk Criteria - references within EC documents Criteria for the physical stability for tailing ponds regarding art /337/EC Criteria for the physical stability for heaps/dumps regarding art /337/EC Criteria (dangerous substances) for major accidents regarding Seveso II directive 96/82/EC Criteria for substance related risks: applicable European/National law for relevant environmental media Single case related risk assessment: serious risk? yes Inventory Appropriate measures no risk non-serious risks Periodically control documentation

6 What should be assessed? Potential risk or danger with regard to Physical stability Human being (health) Environment (water, soil, etc.) Type of waste

7 Inert Waste criteria significant disintegration, dissolution or change to cause health or environment; maximum content of sulphide sulphur of 0,1 %, or maximum content of sulphide sulphur of 1 % and the neutralising potential ratio is greater than 3; (defined as the ratio between the neutralising potential and the acid potential, and determined on the basis of a static test pren 15875) No risk of self combustion and ability to burn; Content of substances potentially harmful to the environment or human health, and in particular As, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, V and Zn, shall not exceed national threshold values; (identified as not contaminated or relevant national natural background levels); Waste is substantially free of products used in extraction or processing that could harm.

8 Risk criteria An assessment of the release of contaminants (short-term and long-term). For the operational period and the long-term period following closure. It shall include an evaluation of the potential hazards constituted by facilities containing reactive waste. Injuries leading to disability or prolonged states of ill-health shall count as serious dangers to human health. Environmental risks are serious, if the intensity of the potential contaminant source strength is not decreasing significantly within a short time; the failure lead to permanent or long-lasting environmental damage; the affected environment cannot be restored through minor clean-up and restoration efforts.

9 Risk criteria (2) Assessing the potential for loss of life or danger to human health or to the environment with regard to the sourcepathway-receptor chain. the quantity and quality including physical and chemical properties of the waste in the facility any relevant, site-specific factors that may influence the potential for loss- of- life or for danger to human health. Where the threshold* exceeds 50 %, the facility shall be classified as Category A. Where the ratio between 5 % and 50 %, the facility shall be classified as Category A, exemptions possible *ratio of the weight on a dry matter basis of: (a) all waste classified as hazardous in accordance with Directive 91/689/EEC and expected to be present in the facility at the end of the planned period of operation, and (b) waste expected to be present in the facility at the end of the planned period of operation

10 Waste characterisation (a) background information; (b) geological background of deposit to be exploited; (c) nature of the waste and its intended handling; (d) geotechnical behaviour of the waste; (e) geochemical characteristics and behaviour of the waste.

11 Information and data necessary for the waste characterisation - in the order to paragraphs 2 to 5 of (2009/360/EC) Existing investigations and studies, including existing permits, geological surveys, similar sites, lists of inert waste, appropriate certification schemes, European or national standards for similar material; quality and representativity of all information shall be evaluated and possible missing information shall be identified; Where information necessary for waste Characterisation is missing - a sampling plan shall be drawn up in accordance with standard EN The results of the characterisation process shall be evaluated. The final result shall feed into the waste management plan.

12 Laws, references, ordinances, standards Directive 2006/21/EC ( Mining Waste ): Europe Article 11: Construction and management of waste facilities...the waste facility is suitable located, taking into account geological, hydrological, seismic and geotechnical factors and is designed so as to meet the necessary conditions for preventing pollutions The waste facility is suitable constructed, managed and maintained to ensure its physical stability and to prevent pollution There are suitable plans and arrangements for regular monitoring and inspection of the waste facility by competent persons

13 Laws, references, ordinances, standards Commission Decision of completing the technical requirements for waste characterisation laid down by Directive 2006/21/EC (2009/360/EC): Waste characterisation shall cover the following categories of information as specified in Annex (choice): a) Geological background of deposits to be exploited b) Geotechnical behaviour of the waste Europe Where information necessary for the charakterisation of the waste is missing, a sampling plan shall be drawn up in accordance with standard EN 14899

14 Geotechnical behaviour: : formulas Geotechnical stability of dams / heaps = f (construction/design, materials, earthworks/ operation) Materials: waste, overburden, mined material Geotechnical characteristics of materials = f (granulometry, plasticity, density and water content, degree of compaction, shear strength and angle of friction, permeability and void ratio, compressibility, consolidation)

15 Laws, references, ordinances, standards Europe Commission Decision on the definition of the criteria for the classification of waste facilities in accordance with Annex III of Directive 2006/21/EC (2009/337/EC): Article 5 1. In the case of loss of structural integrity for tailings dams, human lieves shall be deemed to threatened where water or slurry levels are at least 0,7 m above ground or where water or slurry velocities exceed 0,5 m/s. 2. The assessment of the potential loss of life and danger to human health shall comprise at least the following factors: a) the size and properties of the facility including its design; b) the quantity and quality including physical and chemical properties of the waste in the facility c) the Topography

16 Laws, references, ordinances, standards Europe Commission Decision on the definition of the criteria for the classification of waste facilities in accordance with Annex III of Directive 2006/21/EC (2009/337/EC): d) The travel time of a potential flood-wave to areas where people are present; e) The propagation velocity of the flood wave; f) The predicted water or slurry level; g) The rising rate of water or slurry levels; h) Any relevant site-specific factors that may influence the potential for loss- oflife or for danger to human health. Article 6 1. In the case of waste heap slides any waste-mass in movement shall be deemed likely to threaten human lives if people are staying within range of the moving waste-mass. (a)

17 Laws, references, ordinances, standards (Europe / Germany) Geotechnical standards DIN EN 1997: Eurocode 7: Geotechnical design Part 1 ( ): General rules Part 2 ( ): Ground investigation and testing DIN 4020 ( ): Geotechnical investigations for civil engineering purposes DIN 4084 ( ): Soil Calculation of embakement failure and overall stability of retaining structures Part 5: embankments, water drainage Part 10: earth-fill dams Hydraulic engineering standards DIN ( ): Dam plants Part 10: General specifications Part 11: Dams Part 14: Pumped-storage reservoirs Part 15: Setting ponds DIN ( ): River Dikes

18 Laws, references, ordinances, standards: : Eurocode 7 Europe/ Germany planned heap or pond Geology Existing informations and experiences Strategy for geotechnical design Geotechnical investigations Design of the planned heap and pond Planning and controlling of analysis-program assessement of geotechnical parameters Geotechnical model Geology Field tests Laboratory tests Geological models Experimental results Geotechnical report Geotechnical calculation and design Geotechnical report of the design Design plan Program for review, Control and monitoring Construction works Acceptance of construction work

19 Risk assessment: Eurocode 7 Limit states of earth dams according to Eurocode 7-1 Global stability Slope failure Liquification Deformations, such as excessive subsidence or fissures Frost damages Alterations due to contaminations Earthquake resp. vibration failure Copper open pit, Assaral medet

20 BOX 1 Chemical Charakteristics 1.Sulphide 2.Specific elemental species (Sb, As, Cd, Cr, Co, Hg, Pb, Ni, Tl or Zn) 3. Chemicals used in processing BOX 2 Physial Stability 1. Known failure of facility Pond 1.Height (> 4 m within 50 m) 2.Volume (> m3) BOX 3 Heap 1.Height (> 20 m) 2.Area (> m2) 3.Slope of base (> 1:12 or ~5 ) Receptors 1.Population centres (< 1 km) 2.National Park of Natura 2000 site (< 1 km) 3.Salmonid river (< 1 km) If any of box 1 or box 2 = YES and any of box 3 = YES then Examine further Based on the irish proposal (ad-hoc Group, 4/2008)

21 Establishment of geotechnical stability Conclusions Stages in the Life Cycle of a Tailings Facility Life cycle Site Selection and Design Construction Operation and sequently raised dams Decommission and Closure Methods Reports and projects Monitoring and control Environmental and technical inspections Coordination of the authorities Require- ments Legal framework Capacity and staff Technical guidelines and standards Training: i.e. workshops

22 Conclusions Attention for mining waste and underground / location Attention for chemical and geotechnical characteristics Attention for hazardous and inert waste Operator and Authority requires geotechnical competence Leaching Heap, Assarel Medet

23 Contact: Jörg Frauenstein Thank You Umweltbundesamt Dessau-Rosslau Wörlitzer Platz 1, Dessau-Roßlau