Water-constrained Gauteng may see an acid mine drainage (AMD) quick fix in order to save the fresh water from the Lesotho Highlands Water Project (LHWP) from being wasted on AMD dilution instead of being available to the economy, environmental adviser Dr Anthony Turton said on Wednesday.
Delivering the keynote address to an audience of academics, students and environmental managers – and including former De Beers luminary Nicky Oppenheimer and Tuesday’s keynote speaker Dr Mangosuthu Buthelezi – at the second day of the Oppenheimer De Beers Group Research Conference, Turton drew attention to State failure in the water sector and forecast that pockets of the water value chain would be privatised while water itself remained a State responsibility.
He spoke of the country ultimately transitioning to a water future based on a dual-stream reticulation system of different water of different qualities and prices being used for different purposes.
The former Council for Scientific and Industrial Research water scientist foresaw systemic failure as being inevitable in the water sector in the Gauteng area, which hosts 60% of South Africa’s national economy and 45% of its people.
Short-term failure of critical water supply subsystems would mean a repeat in water of what had already happened in electricity.
Just as on-site generators had alleviated the Eskom power crisis, South Africans would soon need uninterrupted water supply systems that provided strategic on-site back-up in highly engineered systems.
A problem for factories and buildings was the absence of dual-reticulation, which would have to be retrofitted.
Additional water for Gauteng from the second phase of the LHWP would no longer be forthcoming at the planned date owing to tender process hold-ups, which would delay it for at least five years, he told the conference attended by Creamer Media’s Mining Weekly Online.
At the same time, fresh water from the existing LHWP was having to be used to dilute the acidity of water from mines, which meant that the water used for dilution was no longer available to the economy.
To solve this, salts needed to be removed from AMD at source, as had been agreed in 2012, and Phase 2 of the LHWP needed to go ahead without delay.
Had AMD been tackled, there would be no need to use much-needed fresh Lesotho water to up quality levels.
“That would have been an almost instantaneous quick fix but it hasn’t happened,” said Turton, who added that even without a drought, 60% of the national economy is heading for fundamental water constraint.
Far worse that AMD flow was the sewage return flow problem, which he calculated as being a 238 times greater challenge.
Outlining official figures that point to a water deficit by 2025, he identified sewage management as South Africa’s biggest single water crisis with five-billion litres of sewage generated daily and only 20% of that being treated to an adequate level of safety.
A staggering four-billion litres of sewage a day is going back into the system untreated and partly treated with the partly treated sewage being worse than untreated sewage, as only the weak bacteria is destroyed and the strong bacteria is allowed to survive.
South Africa needed to get its head around its microcystin problem, with the State being the country’s biggest single water polluter.
While microcystin in a country like Finland is ten micrograms a litre, South Africa’s microcystin occasionally spiked as high as 18 000 micrograms a litre.
Against that background, between now and 2025 only an abundance of rain could come to the country’s aid.
Variables that need to be guaranteed to facilitate additional economic investment were also water pressure, quality, price, location and time.
As things stood, water-use licences continued to be an issue in mining circles and Turton knew of no mining organisation with a proper functioning water-use licence.
This is not because mines are being deliberately non-compliant but because of it being nigh impossible to comply.
He related a case of dysfunction between regulatory departments last year leading to a legal drought-hit sand-mining operation being shut down in KwaZulu-Natal while illegal mining operations proliferated unhindered alongside it.
Also looming large was the high level of disconnect between national and municipal authorities and the issue of systemic failure lacking the ability to correct itself.
He cited an instance of institutional collapse presenting an insurmountable obstacle toengineering correction and this being exacerbated by political interference damaging adaptive dynamics.
Most bulk potable water treatment plants were designed to precipitate water with suspended solids and provide minimal treatment for bacterial virus using chlorine; they were never designed to turn sewage water into potable water.
Clean water coming into the Vaal dam from natural inflow has been very limited lately.
While the upper Vaal river was low in total dissolved solids (TDS), TDS spikes were being found in the barrage area owing to the inflow of saline sewage water as well as AMD from the Klipspruit and the Blesbokspruit, which both drain the Central basin and the Eastern basin of the Witwatersrand goldfields.
A second AMD source from the Free State goldfields also occurred at a lower point on the Vaal river.
Unlike power shedding, water shedding was impossible owing to the system being designed to work on a positive pressure – negative pressure resulted in the occurrence of vacuums, air and the entry of dirty water into the system that when chlorinated had potential unintended carcinogenic consequences; and the failure of infrastructure was accelerated through water hammering.
As a result of a quarter of the rain gauging stations being lost, the country was currently making use of a similar level of rain gauging capacity that it had in the 1920s.
Insufficient stream-flow gauging stations are also failing to forewarn about the extent of drought impact.
Turton related the case of a new coastal resort in KwaZulu-Natal relying completely on desalinated seawater and renewable energy.
He predicted that long-term water change would be centred on sewage reticulation and the recovery of water and phosphate from sewage as a matter of national strategic importance.
Turton told of having just completed a water assessment for a hotel in Durban, where water was being stored on the roof in very high temperature conditions conducive to the spread of Legionnella disease – an example of the kind of unintended consequence of late quick-fixes.
“Ultimately State failure starts in one little place and it spreads out like a cancer through the system,” Turton told the conference attended by Creamer Media’s Mining Weekly Online.