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LINKS & FAQ’s
LINKS
FREQUENTLY ASKED QUESTIONS
1. Has government allocated adequate resources and funding to address the AMD challenge?
Government is committed to address the matter, but as per the Minister,
cooperation between the mining sector and other important role players is
critical to finding a long-term solution to deal with the AMD challenge.
2. What areas are covered by the long-term solutions study?
The study area lies in the Witwatersrand Goldfields area covering the Eastern,
Central and West Rand underground mining basins, between Randfontein in the west
and Nigel in the east. The study area is being considered in the context of the
water resources of the Vaal River water supply area and associated catchments.
3. What are the effects / consequences of low pH on humans and the environment?
– i.e. the effect of untreated AMD?
Environment: Aquatic life generally cannot survive in a low pH environment, and
hence the receiving rivers may become sterile with little aquatic life (except
if such receiving rivers poses sufficient buffer capacity).
Humans: The water will have a metallic taste due to the metals that may be in
solution. Due to the low pH significant quantities of various heavy metals may
be dissolved in the water that may render it toxic.
A direct relationship between the pH of drinking water and human health effects
is difficult, if not impossible to establish since pH is very closely associated
with other aspects of water quality.
The taste of water, it’s corrosivity and the solubility and speciation of metal
ions are all influenced by pH. At low pH water may taste sour.
The potential toxicity of metal ions and chemicals which can be protonated, for
example ammonia, is influenced by pH. Changes in pH affect the degree of
dissociation of weak acids and bases. This effect is of special importance
because the toxicity of many compounds is affected by their degree of
dissociation.
Corrosion of the water supply system is a major source of metal contamination in
drinking water. Metals that have the potential for causing such contamination
are lead, copper and zinc. Lead is subject to corrosion at a pH higher than 12.
Corrosion of cadmium is only significant below pH 6. Other metals which are
frequently used in household plumbing and that may be affected by pH are copper
and zinc.
4. What are the effects/consequences of high sulphates on humans and the
environment?Consumption of excessive amounts of sulphate in drinking
water typically results in diarrhoea. Sulphate imparts a bitter or salty taste
to water, and is associated with varying degrees of palatability.
SA does not explicitly specify a guideline value for the environment. High
values may have an effect on the aquatic environment, although it has been said
that aquatic eco-systems are able to adapt reasonably well to gradual and mild
changes in salt levels.
5. What dangers will the neutralized and desalinated water hold for humans and
the Environment?
There are no dangers in drinking the neutralised and desalinated water from AMD
if treated to potable water standards. Though the water could be perfectly safe
the public have the perception that it may be unsafe. Society will need to be
informed that fully treated water will be safe. All possible toxic constituents
can be removed to the levels specified by the South African National Standard
(SANS) 241 – 2011 Standard.
6. For what use will the water be treated?
The water can be treated to the quality required by the potential users, these
being either potable water users, industrial water users, or eventual release to
the rivers.
7. Which towns/industries will use the treated water?
The Feasibility Study recommends that it be mostly utilized in the Vaal River
water supply area. It is possible that it can be supplied to either domestic or
industrial users or both.
8. Are any high-rise buildings (or buildings with deep basements) in Johannesburg
under threat because of AMD?
The Johannesburg Central Business District (CBD) is in the Central Basin and the
decant level in the Central Basin is well below the lowest foundations of the
buildings that were reportedly considered by the press to be a high risk.
If the water level is maintained at the Environmental Critical Level (ECL), the
level will be even lower than the expected decant level.
9. What is the Environmental Critical Level (ECL)?
The level above which the water in the mine voids at the critical locations (that
is where the environmental features to be protected are at the lowest
elevations) should not be allowed to rise, to protect specific environmental
features, including groundwater resources.
10. What is the Socio-Economic Critical Level (SECL)?
The level above which the water at the critical location in the mine void must
not be allowed to rise, to protect specific social or economic features, such as
Gold Reef City museum and active or planned mining.
11. Is there a difference in the Central Basin between the ECL and the SECL?
Yes, the ECL is the level that is required to protect the environment, including
shallow aquifers and that is estimated to be safe and should not be breached.
The level that is required to protect the Gold Reef City museum(at the current
position on level 5) can be considered as the SECL and is lower than the ECL.
12. How will the ECL be implemented in the Western Basin?
In the Western Basin the water is at the surface, and actions are being
implemented to lower the water level until it reaches the proposed ECL at 1 600
m amsl. During this process, continued monitoring will be required in order to
ensure that the associated dolomitic aquifers are suitably protected. If this is
not the case, the water level will be lowered further.
13. How will the ECL be implemented in the Eastern Basin?
In the Eastern Basin, the LTS proposes a higher ECL than the Short-Term
Intervention (STI). The way to implement this is to stop the water
conservatively at the lower level and monitor to determine if pollution occurs.
If it is found that the situation has stabilised without any pollution the
underground mine water, the level can be allowed to rise gradually to a next
increment whilst monitoring. In this stepwise way the “highest” level where it
can be considered as “safe” can be determined and considered as the designated
ECL.
14. Is it possible to work towards a solution if the water quality and volume in
the basins are unknown or uncertain?
With future pumping and monitoring the understanding of the dynamics of the water
flow, quality and quantity in the mine voids, etc. will be enhanced and will it
be possible to improve on the management of the system.
15. What are the volumes of AMD that need to be treated?
The treatment of AMD by the High Density Sludge (HDS) process results in
neutralised water which would then need to be desalinated. It is expected that
the long term average volume of water to be pumped and treated is as follows:
Western Basin – 23 Mℓ/24h
Central Basin – 46 M ℓ/24h
Eastern Basin – 80 M ℓ/24h
16. Will the pumps be underground multi-stage dry pumps or submersible
multi-stage pumps?
They will be submersible multi-stage pumps.
17. Is ingress management and control part of the LTS?
Studying or planning control of ingress from surface sources is not part of the
Feasibility Study. It is an on-going separate project by the Department of
Mineral Resources (DMR), driven by the Council of Geoscience (CGS). The LTS
Feasibility Study is looking at how much the volumes could be reduced if ingress
is managed and the potential cost benefit. The study looks at the effect of
ingress prevention and makes predictions of prevention percentages and the
effect on the LTS and design sizes. The Mine Voids Report, which is available on
the DWA website, will provide related information.
18. Where will the treated water be pumped to and will it be desalinated?
In the STI the water from the underground mine voids will be pumped to the HDS
plants at the surface where it will be neutralised and the metals will be
removed before releasing it to streams. For the LTS it will be treated through
neutralisation, metal removal and desalination for distribution to users. It is
important to neutralise the water where it is pumped as there is a high risk
associated with pumping or to transport acidic water over long distances.
Alternative points for discharge or use of the desalinated water are possible.
19. Where will the water in the Western Basin be treated and where will the
neutralised water be discharged to?
The STI works that are currently implemented and partly operational will
neutralise the AMD and remove metals. The partially treated AMD (still
containing elevated sulphate levels) will flow into the Tweelopies Spruit until
the implementation of the LTS. Two treatment “trains” are being upgraded at the
existing Rand Uranium treatment plant to treat the water.
20. When can the long-term solution be expected to be implemented?
Certain implementation actions can already start and from the LTS proposed
program it is clear that desalination works can possibly be operational within 4
years. It is slightly different for the different basins.
21. Who will be responsible for implementing the solution?
Government has mandated DWA for implementing the solution as well as for
operating and maintaining the works. DWA might contract the implementation of
the solution to a third party, but will hold ultimate responsibility.
22. Who will operate and maintain the works?
The DWA takes ultimate responsibility for it and will decide if they need an
agent such as the Trans-Caledon Tunnel Authority (TCTA), Rand Water or a private
institution to run it.
23. Who will pay for the capital, and operation and maintenance cost of the
Long-term Solution?
The Government will take responsibility to ensure that funds are available for
the establishment of the works and construction contracts. Some of the mines
have contributed land, infrastructure (such a pumps), mine shafts for pumping
purposes, etc., while funds will be sourced from the normal Government sources
such as the budget, loans etc. for the LTS. The funding of the works should not
be misconstrued with cost recovery.
24. How will the cost of the AMD works be recovered
The Department supports the polluter pays principle, i.e. the polluter
contributes to the costs for the remedial action taken. Apart from the
contributions by the polluter, there are other revenue streams that can also be
considered, such as that the water users pay. Water users in the Vaal River
System will benefit in two ways, i.e. the treated AMD can be supplied for use
and it will also limit the need for dilution releases from the Vaal Dam, which
will defer the need to implement other water augmentation schemes. In addition,
there may be other beneficiaries (e.g. existing and/ or future underground
mining) who may require a static water level in the mine void that is kept below
the Environmental Critical Level who will need to contribute. The sources for
cost recovery must still be confirmed by the DWA.
25. Will the Polluter Pays Principle apply?
DWA does support the Polluter Pays Principle. It is difficult to commit to a
timeline at this stage, but the Polluter Pays Principle will be applied.
Government needs to engage with the mining industry soon about various aspects,
e.g. access to land and infrastructure and partnering options etc. The
apportionment of liability issue is sensitive. The study report on the
apportionment of liability will inform DWA’s legal strategy and will thus be a
confidential document until such time that the necessary negotiations/ actions
have taken place. The DWA is to engage with the DMR on the subject in due
course.
26. How will the costs of desalinating water for discharge into the Vaal River
ultimately impact on the cost of water to the Vaal River users and agricultural
sector?
The operational cost of the infrastructure for desalination is very high. How the
cost will be recovered and from whom has not yet been decided. The cost of water
to the users of raw water is determined in terms of the Departmental pricing
strategy. The polluter pays as well as the user pays principles will be guiding
principles in this discussion.
27. Were passive treatment technologies considered for the treatment of AMD?
What will happen to the STI infrastructure if an alternative option is decided
upon? Will this not constitute wastage of taxpayers’ money?
All the options mentioned require the water to be neutralised. If a technology
for desalination that does not require any neutralisation can be proven, the HDS
infrastructure may then become redundant. The operational costs for the
treatment of AMD by means of the HDS process and reverse osmosis will be high in
comparison to the capital expenditure (indications are that for approximately
every 8 years, the operational costs may be equivalent to the capital cost). The
LTS looks at the solution for the next 100 years or more and it would thus be in
society’s interest to come up with cheaper technologies. Hence, the cost spent
now on some infrastructure that may become redundant in future can be justified.
28. What is neutralisation?
Neutralisation is a chemical reaction in which an acid and a base interact with
the formation of a salt. In this circumstance the acidity of the water is being
reduced by dosing with alkaline substances such as lime to increase the pH and
precipitate out metals such as Iron to form salts.
29. What is desalination?
Desalination is a process where the salts causing the increase in salinity of
water are removed from the water. This can be achieved by chemical, physical or
biological processes. Chemical processes entail chemical precipitation of
certain elements in the water. Physical processes entail processes such as
Reverse Osmosis (RO), where water is pressed through a membrane that retains the
salts. Biological processes entail the biological reduction of substances such
as sulphates by biological processes. These substances can then be precipitated
in a chemical process.
30. What is the recommended treatment process?
The Study recommends a reference solution based on proven Ion Exchange for the
removal of Uranium, HDS technology for neutralisation and metal removal and
Reverse Osmosis for desalination. During the tender phase the private sector
could come with alternate proposals if it can perform the same function and be
more cost effective.
31. What waste will be generated and how will it be managed?
The Feasibility Study endeavoured to obtain a holistic solution that will limit
the waste products generated by the processes. The reference project will produce
sludge from the HDS and RO process that will be disposed of at a Sludge Storage
Facility and brine that will be disposed of in an evaporation facility.
Although uncertain at this stage it is envisaged that through subsequent
technology development and implementation, the waste products should be in a
state where it could be re-used, and if that is not possible, then it needs to
be disposed of in a safe manner.
Uranium will either be dealt with as hazardous waste, or it can be sold, if
commercially viable.
32. Will hazardous waste be generated from the treatment process?
There are toxic and hazardous substances in the AMD. The treatment processes will
concentrate these, and therefore the treatment, possible re-use and disposal of
the waste products will take this aspect into account to ensure that the waste
handling is conducted in a safe manner.
33. How will the Uranium be managed?
The first step in the handling of the Uranium is to quantify the problem i.e.
establish the state and the volumes of the Uranium. All waste products will then
be analysed to determine the Uranium content, where after the safe disposal
methods and the fate of the Uranium will be established.
34. Will stakeholder inputs be included in the Long-Term Solution Feasibility
study?
The Feasibility Study is a planning study to consider all options for the
Long-Term Solution, and the communication efforts for this study will be
conducted from this perspective.
The inputs from stakeholders will be important in the study. As such, focussed
consultation with key stakeholders and stakeholder sectors/ groups will be
undertaken to assist in identifying sustainable solutions, technical options,
management scenarios, etc. at technical workshops, focus group meetings,
one-on-one meetings and presentations to existing forums.
The wider stakeholder group will be kept informed of progress and key outcomes of
the study through newsletters and press releases distributed at milestones in
the study. Information will be distributed electronically to representatives of
sectors of society/ stakeholder groups, through the media and on the DWA
website.
Stakeholder issues and comments will be picked up in a Frequently Asked Questions
(FAQs) document, which will be updated at intervals during the study when new
information becomes available.
Public participation is to commence as part of the anticipated EIA process for
the LTS.
35. Who is a key stakeholder?
Key stakeholders are parties whose input is critical to the success of the study
and who are able to provide insights that can assist in directing the study and
its outcomes (for example: representatives of National, Provincial and Local
Government, various Non-Governmental Organisations (NGOs), organised business,
mining, industry, labour, agriculture, water utilities, community leaders,
academics etc.).
36. Was the business sector represented on the Study Stakeholder Committee
(SCC)?
Yes, the National Economic Development and Labour Council (NEDLAC), which
represents organised business, and organised agriculture were part of the key
stakeholders represented on the SSC. Other sectors of business were also
involved in focus group meetings, etc.
37. What provision will be made for the remediation of the receptor dams (e.g.
Robinson Lake, Hippo Dam, and Aviary Dam), Tweelopies Spruit east and
eco-systems in the Western Basin?
Diffuse pollution sources, remediation of affected dams, river systems, soil,
etc. and compensation for affected parties falls outside the mandate of the LTS
Feasibility Study. Recommendations for rehabilitation are however provided in
the Implementation Strategy and Action Plan (Study Report 9). Government
(including Departments other than Water Affairs) will have to consider this in
future.
38. Will some of the reports always remain confidential? Tax payers are paying
for the treatment of AMD, and have a right to information.
The Feasibility Study, being a planning study, did not allow for extensive public
participation. Instead, key stakeholders were consulted as the Feasibility Study
progressed, while information was made available to the public through
newsletters and the AMD website. Wider public participation is foreseen during
the implementation stages, including the EIA. With this being said, it must be
stressed that there are certain reports that cannot be made public until the
appropriate implementation process stages have been reached.
The reports dealing with Liability matters will remain confidential until the
objectives of the strategy to engage the mines, have been achieved. The other
confidential reports are linked to the procurement process, which will be kept
confidential until the procurement and tender process is concluded. The
intention is not to keep reports confidential in definitely.
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