National Environmental Management: Waste Act, 2008 (Act No. 59 of 2008)RegulationsRegulations regarding the Planning and Management of Residue Stockpiles and Residue Deposits, 2015Chapter 2 : Planning, Management and Reporting of Residue Stockpiles and Residue Deposits7. Design of the residue stockpiles and residue deposits |
| (1) | The design of a residue stockpile and residue deposit must be undertaken by a registered Professional civil or mining, registered under the Engineering Profession of South Africa Act, 1990 (Act No.114 of 1990). |
| (2) | An assessment of the typical soil profile on the site is required for all residue stockpile and residue deposit. |
| (3) | The design of a residue stockpile and residue deposit must take into account all phases of the life cycle of the residue stockpile and residue deposit, from construction through to post closure and must include the— |
| (a) | characteristics of the residue; |
| (b) | characteristics of the site and the receiving environment; |
| (c) | general layout of the residue stockpile or residue deposit, whether it is a natural valley, ring dyke, impoundment or a combination thereof and its three-dimensional geometry at appropriate intervals throughout the planned incremental growth of the residue stockpile or residue deposit; |
| (d) | type of deposition method used; |
| (e) | rate of rise of the stockpile or deposit; and |
| (f) | design of the pollution control barrier system. |
| (4) | Other design considerations, as appropriate to the particular type of the residue stockpile and residue deposit that must be incorporated include— |
| (a) | the control of storm water on and around the residue stockpile or deposit taking into account the requirements of the National Water Act, 1998 (Act No. 36 of 1998); |
| (b) | a capping layer for residue stockpiles in order to prevent the generation and mobilisation of contaminants of concern; |
| (c) | the provision, throughout the clean and dirty water systems making up the control measures, of a freeboard of at least 0.5 m above the expected maximum water level to prevent overtopping; |
| (d) | keeping the pool away at least 50 meters from the walls and a factor of safety not less than 1,5; where there are valid technical reasons for deviating from this, adequate motivation must be provided and the design must be reviewed by a competent person; |
| (e) | the control of decanting of excess water under normal and storm conditions, including— |
| (i) | the retention of polluted water in terms of the General and Special Standards, requirements for the purification of waste water or effluent, published under Government Notice or Regulation No. 991 of 18 May 1984, where measures may be required to prevent water from the residue deposit from leaving the residue management system; |
| (ii) | the design of the penstock, outfall pipe, under-drainage system and return water dams; |
| (iii) | the height of the phreatic surface, slope angles and method of construction of the outer walls and their effects on shear stability; |
| (iv) | the erosion of slopes by wind and water, and its control by vegetation, berms or catchment paddocks; and |
| (v) | the potential for pollution. |
| (5) | A design report and operating manual must be signed off by a registered professional civil or mining engineer. |