91
Acid Mine Drainage in South Africa Mariette Liefferink

Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

  • Upload
    others

  • View
    0

  • Download
    0

Embed Size (px)

Citation preview

Page 1: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Acid Mine Drainage in

South Africa

Mariette Liefferink

Page 2: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council
Page 3: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

West Wits Pit

Page 4: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

As early as 1987, the US Environmental Protection Agency recognised that “.....problems related to mining waste may be rated as second only to global warming and stratospheric ozone depletion in terms of ecological risk.

The release to the environment of mining waste can result in profound, generally irreversible destruction of ecosystems.”

If this is indeed so then the Witwatersrand gold mining area of South Africa is at serious risk. Reference:s CSIR. Briefing Note August 2009. Acid Mine Drainage in South Africa. Dr. Pat Manders. Director, Natural Resources and the Environment.European Environmental Bureau (EEB). 2000. The environmental performance of the mining industry and the action necessary to strengthen European legislation in the wake of the Tisza-Danube pollution. EEB Document no 2000/016 32 p

Page 5: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

• The potential volume of AMD for the Witwatersrand Goldfield alone amounts to an estimated 350ML/day (1ML = 1000m3).

• This represents 10% of the potable water supplied daily by Rand Water to municipal authorities for urban distribution in Gauteng province and surrounding areas, at a cost of R3000/ML.

• The gold mining industry in South Africa (principally the Witwatersrand Goldfield) is in decline, but the post-closure decant of AMD is an enormous threat, and this could become worse if remedial activities are delayed or not implemented.Reference: CSIR. Briefing Note August 2009. Acid Mine Drainage in South Africa. Dr. Pat Manders. Director, Natural Resources and the Environment.

Page 6: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Reports• 1960

Final Report, Interdepartmental Committee on Dolomitic Mine Water: Far West Rand. DWAF.• 1963

Council for Scientific and Industrial Research (CSIR). “Commentary on the Final Report of the Interim Departmental Committee on Dolomitic Mine Water: Far West Rand”. 28.2.1963/10.2.1964.

• 1995Screening surveys of Radioactivity in the Mooi River Catchment by the Institute of Water Quality Studies of the DWAF.

• 1996Scientists predict West Rand Decant in 2002 and suggested a solution in “An Integrated Strategic Water Management Plan for the Gauteng Gold Mines”. The success of the proposed solution is dependent on the mines, water suppliers, water users and Government adopting an integrated approach – with Government taking the lead role. The Western Utility Corporation developed an alleged technical and economical viable solution, but at the time of writing, Government has not given its approval to this initiative. Government alleges that the polluter cannot be allowed to profit from its pollution.

• 1999Report, “Radioactivity Monitoring Programme in the Mooi River (Wonderfonteinspruit) Catchment”. Institute for Water Quality Studies. DWAF, April. Mining activities are a major contributor to uranium and uranium series radionuclides within the catchment. Concentrations decrease downstream of the sources, indicating removal from the dissolved fraction by interaction with sediments.

Page 7: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

• 2002Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council for Geoscience and commissioned by the DWAF. Wade et al. (2002) (WRC).

• 2002Publication of the “Tier 1 Risk Assessment of Selected Radionuclides in Sediments of the Mooi River Catchment.” WRC Report 1095/1/02 by P. Wade. Radionuclides are concentrated in sediments downstream of their sources. Sequential extractions showed that these radionuclides are distributed in multiple phases within the sediments and that they may be remobilized by environmentally plausible chemical processes such as AMD.

• 2002Coetzee et al. (2002) of the Council for Geoscience reported on “Uranium and heavy metals in sediments in a dam on the farm Blaauwbank”. This study confirmed the findings of Wade et al and used further sequential extractions to characterize the sediments in a dam downstream of mining activities in the Carletonville area.

• 2005Publication, WRC on “Impacts of gold-mining activities on water availability and quality in the Wonderfonteinspruit Catchment.” Mining-related impacts such as large-scale land degradation associated with DWAtering of karstic aquifers and widespread pollution of surface water and groundwater systems are discussed.

• 2005Publication Council for Geoscience, “Contamination of wetlands by Witwatersrand gold mines – processes and the economic potential of gold in wetlands” by H Coetzee et al , Report No. 2005-0106. For more than a century, the mines of the Witwatersrand have discharged contaminated water into the streams and rivers of the area, which led to the formation of a system of large wetlands. Concerns have been raised about their ability to cope with the pollutant loads flowing into wetlands.

• 2006Publication of “An Assessment of Sources, Pathways, Mechanisms and Risks of Current and Potential Future Pollution of Water and Sediments in Gold-Mining Areas of the Wonderfonteinspruit Catchment.” Report, WRC, H Coetzee et al, Council for Geosience. 2004. Report No 1214/1/06. This report eventually became the most important reason for POEA to be established.

Page 8: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

• 2006Publication of “Impact of the discharge of Treated Mine Water, via the Tweelopies Spruit, on the receiving water body Crocodile River system, Mogale City, Gauteng Province”. DWAF, Report, 16/2/7/C221/C/24. 15.12.2006 by J Fourie et al.

• 2006“Dispersion of treated mine water from Harmony Gold Mine Estate into the Wonderfontein Spruit drainage system: Water quality. Vegetation and Bio-monitoring Status Report: Inclusive of water quality improvement potential”. D van der Walt.

• 2006“Archaeological Assessment: The Proposed Wonderfontein Spruit Treated Water Discharge Project.” Matakoma Heritage Consultants. 25 April.

• 2006“Geohydrological Review of the Potential Impact on the Sterkfontein Dolomite during Increased Surface Water Run-off.” J Fourie et al, April.

• 2006Report, Aquatic Biomonitoring and Toxicological Integrity of the Tweelopiespruit and the Upper Wonderfonteinspruit in Relation to the Decant of Mine Water from the Western Basin Mine Void. Winter Cycle 2005.” African Environmental Development. 17 July.

• 2006“Geohydrological Review of the Potential Impact on the Wonderfonteinspruit and Underlying Aquifers During Increased Surface Water Run-Off.” J Fourie et al, May.

• 2007Report, JS du Toit, (Acting Manager: Environmental Manager, Mogale City Municipality). “Background Report on Communities at Risk Within Mogale City Local Municipality Affected by Mining Related Activities, with Special Reference to Radiation & Toxicity.” September.

Page 9: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

• 2007PJ Hobbs (CSIR), Report, “A Hydrogeological Assessment of Acid Mine Drainage Impacts in the West Rand Basin, Gauteng Province.” Report No. CSIR/NRE/WR/ER/ER/2007/009’s7/C.

• 2007Publication of the NNR Report – TR-RRD-07-0006 – “Radiological Impacts of the Mining Activities to the Public in the Wonderfonteinspruit Catchment Area.” 12 July..

• 2007Publication of the “Status Report on the Actions Arising from the Study of Radiological Contamination of the Wonderfonteinspruit Catchment Area (WCA)”. 29 October.

• 2008Publication of the “Situation Analysis of Hydrologic and Hydrogeologic Factors Informing the Royal Engineering Groundwater Supply on Sterkfontein 173iq, Krugersdorp. PJ Hobbs, Report prepared for the Western Basin Void Monitoring Sub-Group. Document Reference Number: CSIR/NRE/WR/ER/2008/0107/, July.

• 2009Publication of Draft Regional Mine Closure strategies for the West, Far West, Central and Eastern Rand Basins.

Page 10: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

GOLD-MINING AREAS OF WEST RAND AND FAR WEST RAND

Page 11: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Witwatersrand Goldfields: Interconnection of mining basinsAcid Rock Drainage and

Mine DrainageLarge Salt Loads

Decanting of Flooded MinesPhysical Instability

Dust PollutionLand Use Conflicts with Growing Urban Centres

Radioactivity and Uranium

Mining Area

Witwatersrand Goldfields:

•Kosh

Basin•Free State Goldfields•Far West Rand •West Rand •Central Rand•Eastern Rand

Key Issues

•Interconnection of mining basins•Acid Rock Drainage and Mine Drainage•Large Salt Loads•Decanting of Flooded Mines•Physical Instability•Dust Pollution•Land Use Conflicts with Growing Urban Centres•Radioactivity (Contamination) and Uranium

Page 12: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

WITWATERSRAND MINING BASIN*

• The Witwatersrand has been mined for more than a century. • It is the world’s largest gold and uranium mining basin with the

extraction, • from more than 120 mines, • of 43 500 tons of gold in one century and • 73 000 tons of uranium between 1953 and 1995. • The basin covers an area of 1600 km2, and • led to a legacy of some 400 km2 of mine tailings dams and • 6 billion tons of pyrite tailings containing low-grade uranium.

*

The Witwatersrand Mining Basin is composed of the Far East Basin, Central Rand Basin, Western Basin, Far Western Basin, KOSH and the Free State gold mines.

A Remote-Sensing and GIS-Based Integrated Approach for Risk Based Prioritization of Gold Tailings Facilities –

Witwatersrand, South Africa –

S. Chevrel

et al

Page 13: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

•Tailings Dams contain 100 000 tons of U

•50 Tons of U discharged annually

•Seepage/Percolation: 24 tons U (1 000 to 1 million higher than the background U concentrations)

Technolgically

Enhanced Naturally Occurring Radioactive Material

•Point Discharges: 12 tons of U

•Stormwater: 10 tons of U

•Sinkholes: Secondary Sources of U contamination

Page 14: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

• Waste from gold mines constitutes the largest single source of waste and pollution in South Africa and there is wide acceptance that Acid Mine Drainage (AMD) is responsible for the most costly environmental and socio-economic impacts.

• As at 1997, South Africa produced an estimated 468 million tons of mineral waste per annum (DWAF, 2001).

• Gold mining waste was estimated to account for 221 million tons or 47

% of all mineral waste produced in South Africa,

making it the largest, single source of waste and pollution (DWAF, 2001).

• There are more than 270 tailings dams in the Witwatersrand Basin, covering approximately 400 km2 in surface area (AngloGold Ashanti, 2004).

• These dams are mostly unlined

and many are not vegetated, providing a source of extensive dust, as well as soil and water (surface and groundwater) pollution (AngloGold Ashanti 2004)

Page 15: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Sinkholes caused by dewatering and rewatering of aquifers

Page 16: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Air Pollution

.

Page 17: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council
Page 18: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Witwatersrand GoldfieldsThe health effects of uranium particles inhaled:

•Small particles are carried by the inhaled air stream all the way into the alveoli. Here the particles can remain for

periods from weeks up to years depending on their solubility.

•Highly insoluble uranium compounds may remain in the alveoli, whereas soluble uranium compounds may dissolve

and pass across the alveolar membranes into the bloodstream, where they may exert systemic toxic

effects.

•In some cases, insoluble particles are absorbed into the body from the alveoli by phagocytosis

into the

associated lymph nodes.•“Insoluble”

particles may reside in the lungs for years,

i h i di t i it t b d i th l li

Page 19: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Witwatersrand GoldfieldsHousing Development (Retirement Village) on Mined Land, within 500m buffer zone of

tailings dam

AMBERFIELD LIFESTYLE ESTATE Congratulations! You have just invested in the West Rand's premier Lifestyle Estate. Every effort has been made to provide you with the services, facilities and care expected of such a prestige development, and as such due diligence has gone into…

Page 20: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

KAGISO

.

KAGISO

Page 21: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council
Page 22: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council
Page 23: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council
Page 24: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council
Page 25: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Uraniferous Tailings

Spillages

Page 26: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

GROUNDWATER POLLUTION

Page 27: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Heavy Metal Contamination

"The mean values for the Wonderfonteinspruit

samples were found to exceed not only natural background concentrations, but also levels of regulatory concern for cobalt, zinc, arsenic,

cadmium and uranium, with uranium and cadmium exhibiting the highest risk coefficients.”

Page 28: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

COLOUR CODING SYSTEM USED FOR TIER 1 RISK ASSESSMENT

Risk quotient Colour Explanation

<0.5 Quotients in this range are unlikely to represent any environmental risk.

0.5-2 Quotients in this range may represent a risk, allowing for analytical and other uncertainties.

>2 Quotients in this range will represent an environmental risk

Page 29: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

0.000 – 0.500

0.501 – 2.000

2.000 – 5.000

5.001 – 10.000

10.001 – 38 642

Page 30: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Uranium Concentration

Page 31: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Nickel Concentration

Page 32: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Arsenic Concentration

Page 33: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Copper Concentration

Page 34: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

RADIOLOGICAL RISKS

The measured uranium content of many of the fluvial sediments in

the Wonderfonteinspruit, including those off mine properties and therefore outside the boundaries of licensed sites, exceeds the exclusion limit for regulation by the National Nuclear Regulator.

For approximately 50% of the 47 sampling sites, the calculated incremental doses of the respective critical group are above 1 mSv

per annum up to 100 mSv

pa (548 mSv

pa Blyvooruitzicht

Mine/Bridge Carletonville)

The radioactive contamination of surface water bodies in the Wonderfonteinspruit

catchment

area caused by the long-lasting mine

water discharges and diffuse emissions of seepage and runoff from slimes dams poses radiological risks to the public resulting from the usage of polluted environmental media;

The pathway sediment→SPM

→cattle→milk/meat→person

(“SeCa”) can cause radioactive contamination of livestock products (milk, meat)

resulting in effective doses of the public in some orders of magnitude above

those

resulting

via

the

pathway

“WaCa

Page 35: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Andries Coetzee’s Dam 900mg/kg U

Photo: Courtesy Dr. Henk Coetzee

Page 36: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Tudor Dam -Elevated levels of radioactivity

10 000 –

100 000 Bq/kg

Regulatory Limits: 500Bq/kg

Page 37: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Courtesy: DME

Page 38: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Draft Regional Closure Strategy For The Far West Rand Goldfield

•An airborne radiometric survey of the WR and FWR was done for DWAF

•Interpretation of the data show many of the residential areas (Carletonville, Westonarea, Khutsong, Kagiso, Randfontein) fall within areas of high risk of radioactivity contamination.

Page 39: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council
Page 40: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

STATUS REPORT ON THE ACTIONS ARISING FROM THE STUDY OF

RADIOLOGICAL CONTAMINATION OF THE WONDERFONTEINSPRUIT CATCHMENT AREA

(WCA)

The study undertaken by the NNR has confirmed the presence of radioactive contamination in the WCA.

Preliminary results of analyses conducted on produce grown in the area have indicated that the dose levels are of radiological concern to the regulator.

The study has also highlighted the need for all the regulators to work closely together since the contamination includes non radiological contaminants such as heavy metals and salts.

Page 41: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

“The most important lesson learnt from the studies in the

Wonderfonteinspruit is that no short-cuts exist which would allow certain pathways to be ignored in a study of radioactive contamination

within these mining areas.”.

Page 42: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

At present the U and other heavy metals, such as cadmium, copper, zinc, arsenic and cobalt are adsorbed in the sediment. Plausible environmental conditions such:

•Acid mine drainage

•Acid rain

•Drying out of the sediment and influx of water

•Dredging operations

•Tailings spillages

•Turbulence caused by cattle drinking the water or children playing in the water can cause the mobilization or transport of uranium in the Wonderfonteinspruit.

Page 43: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council
Page 44: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Central Basin60 Mega Litres

The central basin is currently flooding at 0.9 meter per day (60 ML per day) with no means of intercepting the water prior to reaching surface which will contaminate all ground water and decant on surface in a densely populated area (Boksburg) at three times the rate of the Western Basin.

Photo: Courtesy Prof. McCarthy

Page 45: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Photo: Courtesy Prof. Terence McCarthy

Page 46: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

ACID MINE DRAINAGEEastern Basin108 ML

Photo: Courtesy Elise Tempelhoff

Page 47: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Courtesy: Beeld

Page 48: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

West Rand goldfields

Decanting Volumes: Currently between 18 and 36 ML/per day

An unqualified volume still escapes downstreamNorth and south (intercontinental water divide)

Environmental critical level not absolute decant management solution

Dolomitic

Outlier not a low permeability barrier: faults and fracturesPhoto: Courtesy Henk Coetzee

Page 49: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Chronological Analysis of AMD: West Rand• 1996: SWaMP Report• 2002: Decant• 2002 -2005: Uncontrolled Decant• 2005 – 2009: Partial Treatment• 2009 – Western Utility Corporation (WUC)

Proposal• 21 January 2010 – Uncontrolled Decant• 18 March 2010 - R6.9 (lime treatment)• May 2010 – Revised Directive • 1 July 2010 – Discharge Untreated AMD

Page 50: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

DECANTIn 2002 in the Krugersdorp-Randfontein

area water has

started to decant from a number of shafts into the Tweelopiespruit

and the Wonderfonteinspruit. The water has

a pH of 2.2 (the normal pH is 7.3).

The combination of the pH and redox

driven reactions resulted in a measured uranium concentration of 16mg/l of the Robinson Lake, and resulted in the NNR declaring the

lake a radiation area.

The background U concentration in water is 0,0004mg/l.

In terms of the DWAF regulations for drinking water, the U concentration should not exceed 0.07mg/l and for irrigation,

0.01mg/l.

Page 51: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Distilled WaterDistilled Water

Orange JuiceOrange Juice

VinegarVinegar

Lemon JuiceLemon Juice

Baking SodaBaking Soda

AmmoniaAmmonia

BleachBleach

Battery AcidBattery Acid

1414

1212

1111

1010

99

88

77

66

55

44

33

22

11

00

1313A

lkal

ine

Aci

d

pH (Logarithmic)

DWAF GuidelinesDWAF Guidelines

Drin

king

Wat

erD

rinki

ng W

ater

6.06.0--9.09.0

Irrig

atio

nIrr

igat

ion

6.56.5--8.48.4

Aqu

atic

Eco

syst

emA

quat

ic E

cosy

stem

(Site

Spe

cific

)(S

ite S

peci

fic)

7.07.0--8.08.0

Typi

cal W

its A

cid

Min

e D

rain

age

Typi

cal W

its A

cid

Min

e D

rain

age

2.52.5--44

Page 52: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Robinson Lake pH 2.6

U concentration of 16 mg/l; resulted in the NNR declaring the lake a

radiation area

Page 53: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Pollution Plume

Page 54: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Pollution Plume

Page 55: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Volumes and loads 2005 - Jan. 2010

• Polluted water is discharged into a receiving environment– Volume = ~25Ml/d– Salt content = ~4g/l– Salt load = ~100 tons per da

Photo: Courtesy Dr. Henk Coetzee

20t 20t 20t 20t 20t

Page 56: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Cradle of Human Kind World Heritage Site

Page 57: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

In April 2009 the mine void water, containing sulfuric acid will have been flowing into the Zwartkrans compartment for 8 years – the corresponding void in the dolomite that has formed so far amounts to a staggering 16 700 m3

AAAfricanfrican

EEnvironmentalnvironmental

DDevelopmentevelopment

Page 58: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Ssiesmic RisksDewatering/RewateringJanuary 21, 2010Uncontrolled decant of AMD

Page 59: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

18 Winze

Page 60: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council
Page 61: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council
Page 62: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council
Page 63: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Water Treatment Plant

Page 64: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Precipitated Heavy Metals

Page 65: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Pollution Plume

Radioactive Sludge

Page 66: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

CPS Pit

Page 67: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Acid Mine Drainage

•Waste from gold mines constitutes the largest single source of waste and pollution in South Africa.•Acid Mine Drainage (AMD) is responsible for the most costly environmental and socio-economic impacts. •Production of AMD may continue for many years after mines are closed and tailings dams decommissioned.•AMD is not only associated with surface and groundwater pollution, degradation of soil quality, for harming aquatic sediments and fauna, and for allowing heavy metals to seep into the environment.

Page 68: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Acid Mine Drainage•Long-term exposure to AMD polluted drinking water may lead to increased rates of cancer, decreased cognitive function and appearance of skin lesions.

•Heavy metals in drinking water could compromise the neural development of the fetus which can result in mental retardation.

•If indeed the extent of “… problems related to mining waste may be rated as second only to global warming and stratospheric ozone depletion in terms of ecological risk” (EEB, 2000), then the Witwatersrand gold mining area of South Africa is at serious risk.

Page 69: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Uranium Pollution of Water resources in Mined-Out and Active Goldfields of South Africa –

A Case Study in the

Wonderfonteinspruit Catchment on Extent and Sources of U-

Contamination and Associated Health Risks

Prof.Dr. Frank Winde• “Results indicate that U-levels

in water resources of the whole

catchment increased markedly since 1997 even though U- loads emitted by some large gold mines in the Far West Rand were reduced. This apparent contradiction is explained by the contribution of highly polluted water decanting from the flooded mine void in the West Rand.

• “800kg of U per year flowing into Boskop Dam as Potchefstroom’s main water reservoir

• “Of particular concern is the fact that U-levels in the WFS are comparable to those detected in the Northern Cape which had been geostatistically linked to abonormal haematological values related to increased incidences of leukaemia observed in residents of the area”.

Page 70: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

– Even though a large number of the world’s rivers are contaminated by heavy metals released from present day and historic mining operations, relatively little is known about the effects on communities that live beside and rely on these rivers for food and livelihood. One of the complications is that the toxicity of many metals is a function of such conditions as redox, pH and water hardness.

– Elevated salts and metals can also negatively affect the health of animals in many different ways, depending on the species, age, sensitivity, general health and diet of the consumer, among other factors.

– Some metals, when consumed in excess, can affect organs and the central nervous system, cause reproductive failure or birth defects, and

act as cofactors in many other diseases.

– Certain receptors may be more sensitive than others, depending upon species, age, sex, season, body mass, metabolic rate, general health, diet, behaviour, etc, with younger animals and children being generally more at risk than adults under the same conditions of exposure (WHO).

– The potential for trans-generational (genetic) impacts of bioaccumulated metals and NORMs

(Naturally Occurring Radiactive Materials) on biota exposed above certain thresh-holds.

– The probability that such latent impacts will only be identified

and assessed over the next 100 to 500 years.

Page 71: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

18 March 2010

Page 72: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Tweelopiespruit Inlet

Page 73: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council
Page 74: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council
Page 75: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council
Page 76: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Tweelopiespruit

Page 77: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Tweelopiespruit Downstream

Page 78: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

0

4

8

12

16

20

24

28

32

36

40

44

48

52

56

60

2006

/08/

15

2006

/10/

15

2006

/12/

15

2007

/02/

15

2007

/04/

15

2007

/06/

15

2007

/08/

15

2007

/10/

15

2007

/12/

15

2008

/02/

15

2008

/04/

15

2008

/06/

15

2008

/08/

15

2008

/10/

15

2008

/12/

15

2009

/02/

15

2009

/04/

15

2009

/06/

15

2009

/08/

15

2009

/10/

15

2009

/12/

15

2010

/02/

15

2010

/04/

15

Inflow into Game ReserveFlow Rate Ml/DAY

2006 - 2010

Inflow into Game Reserve V1C

Aviary

No Flow

Page 79: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Inlet to Game ReserveWeekly Oct 2007-May 2010

pH Units

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

17-O

ct-0

717

-Nov

-07

17-D

ec-0

717

-Jan

-08

17-F

eb-0

817

-Mar

-08

17-A

pr-0

817

-May

-08

17-J

un-0

817

-Jul

-08

17-A

ug-0

817

-Sep

-08

17-O

ct-0

817

-Nov

-08

17-D

ec-0

817

-Jan

-09

17-F

eb-0

917

-Mar

-09

17-A

pr-0

917

-May

-09

17-J

un-0

917

-Jul

-09

17-A

ug-0

917

-Sep

-09

17-O

ct-0

917

-Nov

-09

17-D

ec-0

917

-Jan

-10

17-F

eb-1

017

-Mar

-10

17-A

pr-1

017

-May

-10

pH @ 25ºCDirective 9.5Directive 6.5

Page 80: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Aviary Dam Game Reserve OutletWeekly Oct 2007-May 2010

pH Units

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

17-O

ct-0

717

-Nov

-07

17-D

ec-0

717

-Jan

-08

17-F

eb-0

817

-Mar

-08

17-A

pr-0

817

-May

-08

17-J

un-0

817

-Jul

-08

17-A

ug-0

817

-Sep

-08

17-O

ct-0

817

-Nov

-08

17-D

ec-0

817

-Jan

-09

17-F

eb-0

917

-Mar

-09

17-A

pr-0

917

-May

-09

17-J

un-0

917

-Jul

-09

17-A

ug-0

917

-Sep

-09

17-O

ct-0

917

-Nov

-09

17-D

ec-0

917

-Jan

-10

17-F

eb-1

017

-Mar

-10

17-A

pr-1

017

-May

-10

pH @ 25ºCDirective 9.5Directive 6.5

Page 81: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Inlet to Game ReserveWeekly Oct 2007-May 2010

Conductivity mS/m

0

100

200

300

400

500

600

17-O

ct-0

717

-Nov

-07

17-D

ec-0

717

-Jan

-08

17-F

eb-0

817

-Mar

-08

17-A

pr-0

817

-May

-08

17-J

un-0

817

-Jul

-08

17-A

ug-0

817

-Sep

-08

17-O

ct-0

817

-Nov

-08

17-D

ec-0

817

-Jan

-09

17-F

eb-0

917

-Mar

-09

17-A

pr-0

917

-May

-09

17-J

un-0

917

-Jul

-09

17-A

ug-0

917

-Sep

-09

17-O

ct-0

917

-Nov

-09

17-D

ec-0

917

-Jan

-10

17-F

eb-1

017

-Mar

-10

17-A

pr-1

017

-May

-10

Conductivity mS/m@ 25ºC

Directive

Page 82: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Aviary Dam Game Reserve OutletWeekly Oct 2007-May 2010

Conductivity mS/m

0

50

100

150

200

250

300

350

400

450

17-O

ct-0

717

-Nov

-07

17-D

ec-0

717

-Jan

-08

17-F

eb-0

817

-Mar

-08

17-A

pr-0

817

-May

-08

17-J

un-0

817

-Jul

-08

17-A

ug-0

817

-Sep

-08

17-O

ct-0

817

-Nov

-08

17-D

ec-0

817

-Jan

-09

17-F

eb-0

917

-Mar

-09

17-A

pr-0

917

-May

-09

17-J

un-0

917

-Jul

-09

17-A

ug-0

917

-Sep

-09

17-O

ct-0

917

-Nov

-09

17-D

ec-0

917

-Jan

-10

17-F

eb-1

017

-Mar

-10

17-A

pr-1

017

-May

-10

Conductivity mS/m@ 25ºC

Directive

Page 83: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Inlet to Game ReserveWeekly Oct 2007-May 2010

Sulphate mg/l

0

500

1000

1500

2000

2500

3000

3500

4000

4500

17-O

ct-0

717

-Nov

-07

17-D

ec-0

717

-Jan

-08

17-F

eb-0

817

-Mar

-08

17-A

pr-0

817

-May

-08

17-J

un-0

817

-Jul

-08

17-A

ug-0

817

-Sep

-08

17-O

ct-0

817

-Nov

-08

17-D

ec-0

817

-Jan

-09

17-F

eb-0

917

-Mar

-09

17-A

pr-0

917

-May

-09

17-J

un-0

917

-Jul

-09

17-A

ug-0

917

-Sep

-09

17-O

ct-0

917

-Nov

-09

17-D

ec-0

917

-Jan

-10

17-F

eb-1

017

-Mar

-10

17-A

pr-1

017

-May

-10

Sulphate mg/l

Page 84: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Aviary Dam Game Reserve OutletWeekly Oct 2007-May 2010

Sulphate mg/ l

0

500

1000

1500

2000

2500

3000

17-O

ct-0

717

-Nov

-07

17-D

ec-0

717

-Jan

-08

17-F

eb-0

817

-Mar

-08

17-A

pr-0

817

-May

-08

17-J

un-0

817

-Jul

-08

17-A

ug-0

817

-Sep

-08

17-O

ct-0

817

-Nov

-08

17-D

ec-0

817

-Jan

-09

17-F

eb-0

917

-Mar

-09

17-A

pr-0

917

-May

-09

17-J

un-0

917

-Jul

-09

17-A

ug-0

917

-Sep

-09

17-O

ct-0

917

-Nov

-09

17-D

ec-0

917

-Jan

-10

17-F

eb-1

017

-Mar

-10

17-A

pr-1

017

-May

-10

Sulphate mg/l

Page 85: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Inlet to Game ReserveUranium ppb

Weekly Oct 2007 – Apr 2010

0

10

20

30

40

50

60

70

80

90

100

8-O

ct-0

78-

Nov

-07

8-D

ec-0

78-

Jan-

088-

Feb-

088-

Mar

-08

8-A

pr-0

88-

May

-08

8-Ju

n-08

8-Ju

l-08

8-A

ug-0

88-

Sep-

088-

Oct

-08

8-N

ov-0

88-

Dec

-08

8-Ja

n-09

8-Fe

b-09

8-M

ar-0

98-

Apr

-09

8-M

ay-0

98-

Jun-

098-

Jul-0

98-

Aug

-09

8-Se

p-09

8-O

ct-0

98-

Nov

-09

8-D

ec-0

98-

Jan-

108-

Feb-

108-

Mar

-10

8-A

pr-1

08-

May

-10

Uranium ppb

Domestic Guideline 70 ppb

Directive

Page 86: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Aviary DamWeekly Oct 2007 – Apr 2010

Uranium ppb

0

20

40

60

80

100

120

140

160

8-O

ct-0

78-

Nov

-07

8-D

ec-0

78-

Jan-

088-

Feb-

088-

Mar

-08

8-A

pr-0

88-

May

-08

8-Ju

n-08

8-Ju

l-08

8-A

ug-0

88-

Sep-

088-

Oct

-08

8-N

ov-0

88-

Dec

-08

8-Ja

n-09

8-Fe

b-09

8-M

ar-0

98-

Apr

-09

8-M

ay-0

98-

Jun-

098-

Jul-0

98-

Aug

-09

8-Se

p-09

8-O

ct-0

98-

Nov

-09

8-D

ec-0

98-

Jan-

108-

Feb-

108-

Mar

-10

8-A

pr-1

08-

May

-10

Uranium ppb

Domestic Guideline 70 ppb

Directive

Page 87: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Mine Water Dissolved Iron Concentrations vs. pH into TweelopiesWeekly mg/L

Feb 09 – May 10

0

2

4

6

8

10

12

14

0

50

100

150

200

250

300

350

400

02-F

eb-0

9

23-F

eb-0

9

16-M

ar-0

9

06-A

pr-0

9

27-A

pr-0

9

18-M

a y-0

9

08-J

un-0

9

29-J

un-0

9

20-J

ul-0

9

10-A

ug-0

9

31-A

ug-0

9

21-S

ep-0

9

12-O

ct-0

9

02-N

ov-0

9

23-N

ov-0

9

14-D

ec-0

9

04-J

an-1

0

25-J

an-1

0

15-F

eb-1

0

08-M

ar-1

0

29-M

ar-1

0

19-A

pr-1

0

10-M

ay-1

0

pHFe

Fe

pH

Fe Directive

Page 88: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

0

20

40

60

80

100

120

140

2007

/10/

1720

07/1

1/17

2007

/12/

1720

08/0

1/17

2008

/02/

1720

08/0

3/17

2008

/04/

1720

08/0

5/17

2008

/06/

1720

08/0

7/17

2008

/08/

1720

08/0

9/17

2008

/10/

1720

08/1

1/17

2008

/12/

1720

09/0

1/17

2009

/02/

1720

09/0

3/17

2009

/04/

1720

09/0

5/17

2009

/06/

1720

09/0

7/17

2009

/08/

1720

09/0

9/17

2009

/10/

1720

09/1

1/17

2009

/12/

1720

10/0

1/17

2010

/02/

1720

10/0

3/17

2010

/04/

17

V 1Entry into Game Reserve-Manganese

Monthly Oct 2007- Apr 2010

Mn (Dissolved) mg/l

Directive

Page 89: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

Directive – May 2010

Suitable for:Conductivity - Unacceptable DomesticSulphate (SO42~) (mg/L) - NothingManganese (Mn) (mg/L) - NothingIron (Fe) (mg/L) - Unacceptable Domestic +

Livestock watering

Page 90: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

• Latent impacts may take decades, or even centuries, to manifest themselves.

• Inherent water quality risks• Gold mine ore bodies – associated with radionuclides• Hydrological interconnections between mines – cannot

be considered in isolation• Tailings dams and waste rock dumps can never be

maintained in completely reducing environment - water risk ad infinitum

• Long term risk re formation of sinkholes

CLOSURE RISKS AND LIABILITIES

Page 91: Acid Mine Drainage in South Africa · 2015. 1. 30. · Publication of the “Radioactivity study on sediments in a dam on the Wonderfonteinspruit Catchment.” Conducted by the Council

“It is as unacceptable for companies, when they move on, to leave great holes in the earth and polluted rivers as it is to leave disrupted or unenriched communities….” (quoted in Anglo America 2002b:3)