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By Hugo Melo

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Africa

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Hugo Melo

August, 2018

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Bafokeng Tailings Dam
When the Bafokeng tailings dam failed in 1974, liquefied tailings flowed into an adjacent shaft, killing 13 people underground. In 1975 SRK designed a new tailings impoundment to meet a probability of annual loss of life at less than 1 in a million. The complex has operated successfully for more than 25 years; the 40m high decant towers will soon be extended to 80m. This design set South African industry standards.

EARS Project
The Environmental Analysis & Remote Sensing (EARS) project provided the first structurally consistent view of the basins of Egypt, highlighting the control of basin architecture by basement fabric. It included a study of the Red Sea and the structure and stratigraphy of the Jurassic of the Western Desert. EARS resulted in drilling success for one client and, later, a very large gas discovery.

Hex River
The Hex River Tunnel connects Kleinstraat and De Doorns on the main north-south South African rail system. The tunnel was advanced by drilling and blasting. SRK reviewed the contractor's blast design, established whether blasting practice was responsible for reducing the rate of tunnel advance and suggested alternative blast patterns and practices. The project led to the founding of SRK’s Cape Town office in 1979 and contributed to its continued growth.

Merriespruit
The failure of the Merriespruit tailings dam at Harmony Gold Mine at Welkom in 1994 caused extensive damage and loss of life at a nearby mine residential township. SRK was immediately called in and developed post failure stability measures, safety barriers to protect the undamaged portions of the township, and investigated the cause of the failure. Remedial work began seven days later as SRK proposed ongoing safety measures to deal with possible further flows.

Platinum Tailings
From the late 1970’s, SRK has been involved with numerous tailings disposal projects in the platinum-rich Rustenburg and Polokwane areas. This work includes:
- Tailings dams and return water dams at Rustenburg Section, Union Section, Aquarius-Kroondal and Lonmin, with extensions at Lebowa-Atok and Amandelbult Section.
- Tailings dams and extensions at Lonmin and Potgietersrust, with remining at Impala’s Barplats Mine.

Nchanga Mine
The Nchanga Mine is one of the largest copper-producing mines in the world, using both open pit and underground extraction. SRK has since its inception in 1974 been involved in evaluating the stability of the interim pit slopes. Underground extraction using block caving has undermined part of the pit. SRK is assessing the caving system and undermined slope stability to allow extension of the caving further under the open pit, and is designing the final pit slopes.

Mineral Sands
SRK has been involved in many mineral sands projects, beginning with geotechnical work on the mining/dredge ponds at Richards Bay Minerals in the 1980’s. Other projects include Hillendale, Wavecrest, Fairbreeze (in South Africa), Kwale (Kenya), Moma, Tigen and Corridor Sands (Mozambique), where work has ranged from technical reviews, resource estimation, mining designs, geotechnics, tailings disposal, environmental assessments, and water supply studies.

Lesotho Project
This project transfers water from the mountain highlands of Lesotho to the highly industrialized, but water-poor, Witwatersrand region. In the first phase, SRK was involved in work on the 180m high concrete arch Katse Dam and appurtenant structures, and approximately 100km of transfer and delivery tunnels. Our role was to investigate options, undertake site investigations, prepare designs, tender drawings and documents, adjudicate tenders and perform construction inspections.

Ceres Dam
Located on the Koekedouw River upstream of Ceres in the Western Cape, this dam is 62m high and is designed to supply 17 million m3/annum (cubics per meter), including a portion allocated to emerging farmers. The dam is the first in South Africa to have an asphalt-concrete core; to be funded by both private and state sources and by permit, to release water for the environment. Built on the site of the old dam, challenges included maintaining water supply during construction.

Standard Bank Superblock
The Standard Bank Administration Building was constructed on land on which the Main Reef/Main Reef Leader and South Reef stopes outcropped, causing undermining and foundation problems. This led the authorities to severely restrict development. SRK inspected the accessible old underground workings, and proposed a stabilization method, constructing in-stope concrete pillars. SRK used a pseudo-three dimensional method of stress analysis to space and size the pillars. Authorities approved the stabilization method; the structure has been in use since 1984.Lorem ipsum dolor sit amet, consectetur adipiscing elit.Mauris non blandit purus.Suspendisse vel libero semper, consectetur sapien eget, suscipit nulla.Sed elit diam, commodo eu augue a, tempus vulputate leo.

Kowyn's Pass
Kowyn’s Pass near Graskop in the Eastern Transvaal has a history of cliff instability. Instead of anchoring the unstable boulders, SRK proposed a rockfall shelter. The costs were comparable to the anchoring methods, so the client accepted SRK’s alternative. SRK completed the design, tender and construction supervision for the project – a first in South Africa. The road beneath the rockfall shelter has been open to traffic ever since 1980.

Skorpion Mine
The feasibility study for Anglo American’s Skorpion Mine and refinery in Namibia was managed by Reunion Mining as part of a “buy-in” agreement with Anglo American. SRK audited this study as it was prepared to ensure that it satisfied the requirements stipulated in this agreement. The mine was commissioned in September 2003 and is now a world class, low cost, zinc producer.

Geita Gold Mine
SRK has been involved with Anglogold Ashanti’s 600koz per annum Geita Gold Mine in Tanzania since 1996, when Ashanti bought rights to the licence from Cluff Resources. Later, when Ashanti purchased SAMAX and added the Kukuluma and Matandani prospects, we valued both parties’ relative interests in the project. Since then, SRK has completed environmental studies, audited the project for debt financing, and designed and supervised the technical completion tests that confirmed the project had met its production targets.

Maguga Dam
This clay-core rockfill-type dam, at 115m high, is the second highest embankment dam in Southern Africa. It falls within a large catchment which experiences cyclonic rainfall; the design challenge for flood flows was solved with a very large labyrinth spillway of 15000m3/s. Built for irrigation, it also supplies water to Pigg’s Peak and can provide hydropower.

Eskom/Kriel
In 1987 the Eskom power generating authority in South Africa invited tenders for the privatization of ash disposal from the Kriel thermal station, their first privatization initiative. Each year, Kriel burns 9 million tonnes of coal, generates 3000 MW/hour, and produces 2.5 million tonnes of ash. As part of a consortium, SRK was contracted to design and operate the facility for 10 years. During this period, SRK improved the facility to meet more stringent environmental and safety legislation.

Ghana Mine
Goldfields Ghana Limited (GFGL) operates the Tarkwa open pit/heap leach gold mine and the Damang open pit/CIL plant. In 1996, SRK authored the original Tarkwa feasibility study and has since worked closely with GFGL. In 2002, SRK completed the Tarkwa strategic analysis study. GFGL is now constructing a new CIL plant and moving from contractor to owner-mining. GFGL and SRK recently completed a strategic analysis at Damang, investigating additional mining prospects. SRK provided technical services including geotechnics and pit slope design.

AECI
AECI has manufactured explosives and chemicals for the last 100 years on numerous sites. However, waste handling practices in the past do not always meet today’s standards. As a result, the soil, groundwater and surface water is contaminated in differing degrees. With AECI, SRK identified the nature and extent of contamination at more than 200 sites, and is designing and implementing remedial measures. A computer-based land management information system has been developed to monitor the process.

Mining Finance
SRK has been the independent technical advisor and competent person to some groundbreaking transactions, including the formation of Gold Fields Limited (merger of Goldfields of South Africa and Gengold) and of Anglogold (and its acquisition of Minorco’s gold assets), the listing of Kumba Resources, ARM Gold and Harmony, the merger of ARM and Harmony and the recent acquisition of Avgold by the merged entity.

De Beers Mine
Since its South African inception in 1974, SRK has been involved with the De Beers group, providing services for open pit slope design, ramp stability, geotechnics, water supply and tailings dam design and implementation. Sites include: the Finsch, Koffiefontein, Cullinan and Venetia mines in South Africa, and the Lethlakane, Orapa and Jwaneng open pits in Botswana.

Sishen Iron Ore
In the early 1990’s SRK conducted a review of the Sishen Life-of-Mine Plan for Iscor, now Kumba Resources. During the 2003/2004 financial year Sishen produced 27.5 million tonnes of product and 60 million tonnes of  waste. Their long, medium and short term plans range from one week to 10 years. SRK analyzed all aspects of the Life-of-Mine Plan and made recommendations. This review, one of the first to be performed in the world, led to the establishment of SRK's due diligence team.

SAB Miller
For more than 20 years, SRK has been an active partner with SAB Miller, the second largest malt brewer in the world. This association primarily concerns water and wastewater management, reducing their water to beer ratios from >10:1 to a present industry standard of <5:1, achieving substantial savings. Optimizing fresh water intake at the beginning of the process is important, as is minimizing the wastewater generated at the end. SRK has helped as SAB expanded into Russia, China, eastern Europe, as well as more than 10 countries on the African continent.

Lebalelo Pipeline
The Lebalelo Pipeline transports raw water from the Olifants River to mining operations at the Bushveld complex. It includes: a river offtake weir, a de-silting facility and storage dam, high level and secondary pumpstations, connecting steel pipelines, a concrete reservoir and five earth dams. It also supplies water to 1.3 million rural people, a function identified as crucial for sustainable development in the region.

Stormwater
Based on national and international experience, SRK’s innovative approach to stormwater management benefits clients and communities in developed areas by identifying and ranking “at risk” areas, reducing flooding and potential liability claims expeditiously, reducing potential flood damage costs and capital expenditure. And in undeveloped (developing) areas, with SRK’s help, authorities can create an integrated catchment approach, manage flood-prone areas and select appropriate development strategies.

Environment
A State of the Environment Report (SoER) provides governments with credible information on the condition of economic, social and natural environments. SoERs monitor the effectiveness of policies and programs designed to improve the quality of life and monitor progress towards achieving sustainable development. SRK’s involvement in SoERs for the Gauteng Province, the Ekurhuleni Metropole, the Midrand Municipality, the Western Cape Metropole and the Knysna Municipality is influencing policy development in South Africa.

Research
In recent years interest in the research and application of constructed wetlands for waste water treatment has grown. The systems offer an efficient and adaptable option to treat domestic effluent, upgrade conventional pond systems and treat a range of effluents, including Acid Mine Drainage. SRK has been involved in developing the design, implementation, management and operation of these systems, as it has for a variety of R&D projects for major organizations and research bodies.