IMESA The official magazine of the Institute of Municipal Engineering of Southern Africa
infrastructure development • Maintenance • service delivery
Municipal Focus Developments in Ekurhuleni
ERWAT shares new thoughts on wastewater Tumelo Gopane Managing Director, ERWAT
Keeping Durban Heights Reservoir watertight
Delivering on Cape roads
Infrastructure funding Building a renewable asset class
IN THE HOT SEAT The emerging contractor market is one of our niche focus areas, since this is a government priority for future procurement spending. We’re here to support the growth of these SMEs with the best plant and machine match.” Rocco Lehman Managing Director, Ammann South Africa ISSN 0257 1978
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volume 43 no. 05 May 2018
IMESA The official magazine of the Institute of Municipal Engineering of Southern Africa
INFRASTRUCTURE DEVELOPMENT • MAINTENANCE • SERVICE DELIVERY
Municipal Focus Developments in Ekurhuleni
ERWAT shares new thoughts on wastewater Tumelo Gopane
A case for membranes
Managing Director, ERWAT
Keeping Durban Heights Reservoir watertight
Delivering on Cape roads
Infrastructure funding Building a renewable asset class
IN THE HOT SEAT
“Our vision is for ERWAT to become the entity supporting wastewater across South Africa as well as outside the borders,” explains Tumelo Gopane, managing director, ERWAT. P14
The emerging contractor market is one of our niche focus areas, since this is a government priority for future procurement spending. We’re here to support the growth of these SMEs with the best plant and machine match.” Rocco Lehman Managing Director, Ammann South Africa ISSN 0257 1978
V o l u m e 4 3 N o . 5 • M a y 2 0 1 8 • R 5 0 . 0 0 ( i n c l . VAT )
The big picture A case for membranes Keeping Durban Heights watertight for 27 years
The increasingly busy N1 highway between Durban Road and the R300 route near Cape Town is getting a third lane in both directions – with a special blue stone from the Rheebok Quarry of leading construction materials supplier, AfriSam. P6
A safer, smoother Cape Town commute
Geotechnical Engineering Founding on dolomite
Efficient solutions for Cape Town Casting the perfect mould
3 5 9 56
Geogrid improves safety Founding on dolomite
Ammann: The value proposition
Industry Insight ERWAT shares new thoughts on wastewater
City of Ekurhuleni Lekwa: Taking a holistic approach An airport city unfolds Pumping technology perfected Accelerating municipal water infrastructure The smart choice Infrastructure Funding Building an asset class
16 19 20 22 25
Roads & Bridges 30 years in Tshwane Controlling silica dust exposure
Infrastructure Funding Building an asset class
Pumps & Valves
Tracing its roots back to 1869, Ammann is one of the world’s most respected OEMs, leading on all continents with innovative solutions for the construction industry. IMIESA talks to Rocco Lehman, managing director of Ammann South Africa, about local developments. P10
Editor’s comment President’s comment Africa round-up Index to advertisers
Efficient solutions for Cape Town
Pumps & Valves
Transport, Logistics, Vehicles & Equipment Efficient excavation Compact by design A solution for every task
47 48 49
Breakthrough for precast New line for Walmer Tips for extended durability Carving a competitive niche Earth building at Langbos
50 51 52 54 56
Cement & Concrete
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he rate of informal settlement growth in and around South Africa’s major cities and towns is staggering and with this comes an urgent need to make provision for essential services. In some cases, the growth is so significant that mini towns are being formed that threaten to overrun established suburbs. The land bordering Cape Town’s N2 freeway is a prime example, where the transition from temporary shelters to formal housing has been occurring for decades in places like Khayelitsha – now said to be one of South Africa’s fastest growing townships. Around 70% of Khayelitsha’s residents live in shacks and the actual population is unknown. During the 2011 census, it was bordering on 400 000, but the figure is currently well over a million. This escalating migration from impoverished rural areas presents a major challenge for town planners and municipal engineers. It stretches budgets that are already struggling to keep pace with existing infrastructure maintenance. Another factor to consider is that these informal settlements don’t contribute to municipal revenue flows derived from property rates, waste collection, electricity and water.
Advertising Sales Jenny Miller Tel: +27 (0)11 467 6223 Email: email@example.com ___________________________________________________
Publisher: No. 9, 3rd Avenue, Rivonia 2056 PO Box 92026, Norwood 2117 Tel: +27 (0)11 233 2600 Fax: +27 (0)11 234 7274/5 www.3smedia.co.za Annual subscription: R600.00 (INCL VAT) ISSN 0257 1978 IMIESA, Inst.MUNIC. ENG. S. AFR. © Copyright 2018. All rights reserved. ___________________________________________________ IMESA CONTACTS HEAD OFFICE: Manager: Ingrid Botton P.O. Box 2190, Westville, 3630 Tel: +27 (0)31 266 3263 Fax: +27 (0)31 266 5094 Email: firstname.lastname@example.org Website: www.imesa.org.za BORDER Secretary: Celeste Vosloo Tel: +27 (0)43 705 2433 Fax: +27 (0)43 743 5266 Email: email@example.com
Revenue and expenditure Municipalities receive National Treasury allocations for infrastructure roll-outs, but a portion still needs to be self-generated, so what does the current revenue and expenditure pattern look like? Here, Stats SA’s Quarterly Financial Statistics of Municipalities report provides a broad indication. According to the report, around R83.9 billion was spent by the country’s 257 municipalities during Q4 2017. Eskom electricity purchases were the highest expenditure item at 19.6%, followed by employee costs at 30%. Contracted services amounted to 7.1%, general expenses 7.5% and water purchases 5.7%. In turn, total revenue inflows for Q4 2017 came to R92.5 billion. The largest revenue contributors were grants and subsidies received from national government (30.7%), followed by electricity sales (26.2%).
EASTERN CAPE Secretary: Susan Canestra Tel: +27 (0)41 585 4142 ext. 7 Fax: +27 (0)41 585 1066 Email: firstname.lastname@example.org KWAZULU-NATAL Secretary: Ingrid Botton Tel: +27 (0)31 266 3263 Fax:+27 (0)31 266 5094 Email: email@example.com NORTHERN PROVINCE Secretary: Rona Fourie Tel: +27 (0)82 742 6364 Fax: +27 (0)86 634 5644 Email: firstname.lastname@example.org SOUTHERN CAPE KAROO Secretary: Henrietta Olivier Tel: +27 (0)79 390 7536 Fax: +27 (0)86 629 7490 Email: email@example.com WESTERN CAPE Secretary: Michelle Ackerman Tel: +27 (0)21 444 7114 Email: firstname.lastname@example.org FREE STATE & NORTHERN CAPE Secretary: Wilma Van Der Walt Tel: +27 (0)83 457 4362 Fax: +27 (0)86 628 0468 Email: email@example.com All material herein IMIESA is copyright protected and may not be reproduced either in whole or in part without the prior written permission of the publisher. The views of the authors do not necessarily reflect those of the Institute of Municipal Engineering of Southern Africa or the publishers.
shack dwellers Extracting the real value from these numbers is challenging when you consider that a high percentage of municipalities are heavily indebted (sometimes due to wasteful expenditure), with vast amounts outstanding to Eskom and the Department of Water and Sanitation. And there’s a fair amount of money being spent on municipal salaries, but to what end?
Tshwane model The City of Tshwane shows what can be achieved within the current constraints. Under the leadership of Executive Mayor Solly Msimanga, Tshwane’s financial position has seen a steady improvement over the past two years in office. Unauthorised expenditure reduced from R1.6 billion in 2015/16 to R634 million in the succeeding financial year. Meanwhile, cash and cash equivalents improved from R1.1 billion to R2.1 billion over the same period. That translates into more money freed up and available for service delivery, alongside national government allocations, for initiatives like human settlements. A key factor in Tshwane’s ‘stablise, revitalise and deliver’ mandate has been its talent retention and recruitment strategy, appointing the right people and putting an end to the previous administration’s multitude of supernumerary acting posts, referred to by Msimanga as the ‘the Hollywood style of government’. When it comes to any project, and especially housing, throwing money and people at a problem without having a longer-term solution is not going to solve the problem. The situation is too urgent and the backlog endless. Like other metros, Tshwane has recognised this and tabled a pro-poor budget and Integrated Development Plan that sets the right building blocks in place. Plus, the approach of providing serviced stands first, which can make way for formal housing structures later, is a good one in trying to catch up on the backlog.
To our avid readers, check out what we are talking about on our website, Facebook page or follow us on Twitter and have your say. struc www.infra
magazine The official of the Institute l Engineer ing of Municipa Africa of Southern
• SERVIC • MAINTE NANCE
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nts Deve lopme in Ekurh uleni
IND US TRY INSIGHT new ERWAT shares wastewater thoughts on Tumelo Gopane Managing Director,
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Keep ing Durba voir Heigh ts Reser water tight
AfriSingam on Deliver Cape roads
funding Infrastructure able Build ing a renew asset class
since this SEAT is one of our niche focusng.areas, to We’re here ” IN THE HOT market spendi procurement ng contractor machine match. plant and The emergi y for future ment priorit with the best is a govern these SMEs South Africa growth of r, Ammann support the
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More industry traction required As we progress through the second quarter of 2018, the expectations from the civils industry remain muted. However, on the upside, there is room for optimism as the metros embark on concerted drives to deliver on their infrastructure mandate.
IMESA president Gavin Clunnie
good example is the draft budget put forward by the City of Cape Town’s Transport and Development Authority (TDA) for its new financial year commencing 1 July 2018. A portion of the money will be drawn from the city’s ratepayers via proposed tariff increases, but that’s inevitable. Key investments in infrastructure tabled by the city include an allocation of R585 million for new housing developments during 2018/19, and a total of R2.1 billion in expenditure planned over the medium term (2018/19 to 2020/21). The city also proposes spending more than R850 million over the next few years on informal settlements upgrades and backyarder ser vices. That includes some R150 million for electrification. Another key focus area is the allocation of over R1.5 billion for public transpor t. This
will include new roads and the roll-out of Phase 2A of the MyCiTi ser vice. All of these projects are designed to tie in with the city’s future spatial development planning. Although this is just a quick snapshot of Cape Town’s future activities, the point to bring across is that similar numbers and priority areas have also been tabled by the other metros going into 2018. So there should be a massive project pipeline, and lots of work. But the current outlook for contractors still isn’t looking that positive in the shor t term.
Confidence levels As an industr y barometer, economic surveys are a good indicator of confidence levels. And in the most recent Construction Industr y Development Board (CIDB) SME Business Conditions Sur vey for Q1 2018, there are some mixed results. This sur vey covers CIDB grading levels 3 through 8 for contractors operating in the building and civils sector: essentially, activities remain constant, but at lower levels and with reduced profitability. In building, the confidence level for Western Cape building contractors was recorded at 54 index points (50 being neutral and 100 representing extreme confidence). This was against an overall industry rating of 36. The other major provinces – namely the Eastern Cape, Gauteng and KwaZulu-Natal – averaged out at 30.
The mood of the civils sector in Q1 was equally subdued, with confidence levels also at 36 points. Interestingly, for Western Cape civils contractors the CIDB sur vey repor ted that “confidence plunged to its worst level since Q2 2013.” So the current plans by the City of Cape Town will definitely be welcomed by contractors based there, but the same is true nationwide.
Education and training As IMESA, we feel that there needs to be more engagement. Our goal is to ensure that we facilitate this process in the municipal space alongside key bodies like the South African Local Government Association. This includes a more concer ted focus on education and professional registration to suppor t municipalities as they focus on addressing technical skills gaps that currently hamper the speed of infrastructure deliver y. In this respect, we are also working closely with other engineering institutes. Our 82nd IMESA Conference will ser ve as an excellent platform for bringing key industr y professionals together to map the way for ward. Registrations are now open and we’re looking for ward to an excellent turnout. It’s definitely time for innovative infrastructure solutions.
2018 IMIESA May 2018
In one of the largest contracts undertaken by Western Cape contractor Martin & East, the busy N1 highway between Durban Road and the R300 near Cape Town is getting a third lane in both directions, with a special blue stone supplied by leading construction materials supplier AfriSam.
his R514 million project is being under taken by the Western Cape Department of Transport and Public Works and began in early 2016. The project aims to significantly reduce congestion levels. It is estimated that 120 000 vehicles use the route daily, leading to regular and severe traffic delays during peak periods. According to Eitner Truter, contracts manager at Martin & East, the project is making some important safety improvements to the interchanges. This includes the Jip de Jager Road, Plattekloof Road, Durban Road and Old Oak Road interchanges where widening of onand off-ramps and improving of signalisation is being done. “In-between these intersections, auxiliary lanes are being added to create a safer, more gradual merge of traffic into the faster N1 highway traffic,” says Truter. “Adding the additional lane into the median, on the north-
A safer, smoother Cape Town commute and south-bound carriageways, means the concrete median barrier needs to be extended from the Jip de Jager Interchange onwards to the R300 Interchange.”
UTFC The extra lane being constructed mainly uses an ultra-thin friction course (UTFC) design over the 8 km from the Plattekloof Interchange to the R300 Interchange, covering a total of 436 500 m2. UTFC has been specified to improve the roadway safety qualities as it provides superior drainage, due to the shape and size of the smaller UTFC stone. Bradley Thomas, territory sales manager at AfriSam, highlights the cubical nature of the 9 mm and 13 mm stone, quarried and crushed at AfriSam’s Rheebok quarry. This particular stone has low levels of flakiness and creates the interconnected voids in the final 24 mm asphalt layer. Water on the road surface drains via the top layer to the sides of the highway, channelling safely into drains and pipes. “Using an opengraded mix allows water to travel through the interconnected voids between the stones, and off the road surface,” Truter says. Less water on the surface means vehicle tyres have improved grip so there is less risk of vehicles aquaplaning and of water spray impairing driver visibility. An added advantage is lower tyre noise, which is another reason why UTFC is gaining popularity in road design specifications in South Africa. The
From left, Bradley Thomas, AfriSam territory sales manager, and Eitner Truter, Martin & East contract manager, at the N1 road works near Cape Town, with the iconic Table Mountain, Lion’s Head and Signal Hill on the horizon
IMIESA May 2018
UTFC asphalt mix is being supplied by Much Asphalt’s Contermanskloof Plant, established on the site of AfriSam’s Peninsula Quarry and within easy reach of the N1 construction. As the country’s largest supplier, the company has taken a leading role in keeping South Africa at the cutting edge of asphalt technology and it was the player that introduced UTFC to the local market. Ensuring the highest-quality standards, Much Asphalt’s plants are wholly South African designs, working in compliance with ISO 9001:2000 quality systems. The company operates its own certified laboratory in Cape Town for product testing.
Readymix solutions In addition to supplying the aggregate to Much Asphalt, AfriSam is also providing aggregates for the concrete mix design for the readymix being used on a number of applications on Martin & East’s contract. Among the main applications are in situ median barrier units, 10 retaining structures on the outer edges of the highway, overhead gantry base structures, concrete-lined v-drains and the rebuilding of the 60-year-old bridge over the N1 on Old Oak Road. “The addition of new lanes required this bridge to be demolished, as the vertical and horizontal clearances did not allow for the new legalised height limits for abnormal truck loads as well as the widening of the highway into the median area. A rebuild was necessary to reposition the
AfriSam’s systems ensure punctual arrival and discharging at site within strict time restrictions
COVER STORY The UTFC stones specified for the contract are quarried and crushed at AfriSam’s Rheebok Quarry
Martin & East is constructing two extra lanes on the N1 in the median between the north- and south-bound carriageways. In the centre, reinforcing steel is set in the foundations for the new median barrier
piers,” says Truter. In addition, the bridge needed to be raised 900 mm to meet modern highway regulations. Work on the Old Oak Road bridge, which included concrete pours for the abutments, columns and spans, is over 60% complete, with two of the three spans completed by April 2018. The last span will be done by July 2018, after which pre-stressing starts, and bridge completion is expected in August or September this year. All approaches are planned to tie in with the increase in the bridge’s elevation.
Dam pipeline relocation A further important element was relocating the water pipeline from Wemmershoek Dam to Cape Town. This used to run down the centre of the median. However, with the road and median barrier being extended, 2.5 km of the 12 m diameter pipeline had to be moved to the shoulder of the incoming N1 lane. This ensures that it will remain accessible from the surface, at a depth of about 3 m.
“This required four pipe-jacks under two of the four interchanges, as well as ensuring that the three million litres of water in that section of the pipe was not lost during the diversion process,” Truter says. This was achieved by transferring the water from the pipeline, using a pump station in Fairtrees Road, to the Glengarry reservoir, ensuring it could be used in the Durbanville area. Truter also highlights how the traffic intensity on this route makes for challenging logistics. Keeping the seven construction teams working in coordination while ensuring on-time deliveries from suppliers and maintaining high plant utilisation is no mean feat on this contract. “Disruptive work, such as lane closures, is not permitted during peak-hour traffic, for example,” he says. Thomas emphasises that this demands perfect timing from AfriSam, especially with its readymix concrete deliveries for the median barrier.
“AfriSam systems ensure that our trucks arrive punctually and discharge the readymix within the strict time restrictions, despite the difficult traffic conditions,” Thomas explains. “Failure to do this could delay the entire construction process, perhaps by as much as a day, so there is no room for error.” Thomas also emphasises the critical importance of AfriSam’s concrete quality management under these conditions. “The limited window of opportunity to deliver the concrete makes it even more vital that quality is on spec at all times,” he says, “For this reason, a lab technician tests the slump at the AfriSam plant just before the truck leaves for site, and then accompanies the truck to site with the results.” By April 2018, the number of personnel on-site was peaking at about 215 people, including management, labour and subcontractors, says Truter. Progress to date has been solid, with about half of the three-section contract completed. The first section of the highway has been completed, the second section is due for completion in August 2018, and the last section will be done by March 2019. www.afrisam.co.za
Milling of the road surface on the N1 conducted by Zebra Surfacing, a subsidiary of Martin & East
IMIESA May 2018
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FROM AROUND THE CONTINENT
Egypt is investing $51 billion in a national water management plan
The Kagitumba-KayonzaRusumo road project will facilitate travel and trade between Rwanda and Uganda
The rehabilitation and widening of the 208 km Rwandan stretch of road will include two cross-border markets at Egypt has pledged to invest E£900 billion (R610 billion) in Kagitumba (on the Rwanda/Uganda border) a national water management plan over 20 years. and at Rusumo (on the Rwanda/Tanzania The country faces a 30 billion m3/day water deficit, border), and the rehabilitation of 10 milk which is expected to intensify once the Grand collection centres and 10 boreholes, Renaissance Dam (GERD) comes online. Egypt among other activities. estimates that the dam, built by Ethiopia, will reduce This will provide training for 1 600 women, Nigeria aims to produce Nile water flowing into the country by 20%. seven women associations and facilitate the 28 000 MW of electricity This follows an announcement by the president of planting of 41 500 trees. by 2035 plans to build a mega desalination plant in response to The project is expected to ease access to water scarcity concerns. Egypt has 40 desalination plants in markets, reduce the cost of doing business and operation, and aims to build or upgrade a further 15 facilities by increase the value of agricultural produce, and create jobs 2021, adding a targeted 700 000 m3/day. for the local people – thereby increasing household income. The Al Yusr desalination plant in Hurghada, on Egypt’s Red Sea coast, officially came on-line in January 2018, adding desalination capacity of 110 000 m3/day and taking the country’s total desalination capacity to 250 000 m3/day.
Stepping up water security
28 000 MW
Nigeria Electricity master plan The Nigeria Federal Government has unveiled a 20-year transmission master plan aimed at producing 10 000 MW of electricity by 2020 and 28 000 MW by 2035. The plan was reportedly put in place not only to increase the country’s power production capacity, but also to enable it to export power that is not being used in order to prevent wastage. The plan allows for 387 MW to be exported from the 10 000 MW target of 2020. In 2025, when capacity is expected to reach 15 000 MW, 1 540 MW is marked for export, while 2 000 MW will be available for export in 2035.
Rwanda Roads connecting nations Rwanda has launched the rehabilitation and widening of the Kagitumba-Kayonza-Rusumo road in the Eastern Province of Rwanda. The project will directly serve 1.1 million and facilitate travel and trade between Rwanda, Uganda and the East African region. This forms part of a multinational project valued at US$376.5 million, of which $183.39 million is for the Rwanda component. In Uganda, the four-lane 23.7 km Busega-Mpigi express highway will be constructed.
IMIESA May 2018
Tzoneva’s new Prime 140 asphalt plant
The value proposition Tracing its roots back to 1869, Ammann is one of the world’s most respected OEMs, leading on all continents with innovative solutions for the construction industry. IMIESA talks to Rocco Lehman, managing director of Ammann South Africa, about local developments. Is customer engagement a contributing factor in Ammann’s success to date? RL This is definitely the case. At Ammann, we have a total solutions philosophy that goes well beyond simply machine sale. A great example of this was the Customer Day held in Benoni during November last year, which was co-hosted with ELB Equipment, our Southern African dealer. The function was held at Instant Tar’s facility, and also served as an opportunity to showcase the new 90 tonne per hour Apollo Counter Flow 90 continuous mixing plant, commissioned by Ammann towards the end of 2017. The feedback was generally excellent. Customers had the opportunity to hear presentations from leading Ammann experts, based at our factories in Europe and India. The Customer Day coincided with a Training Campus for our Ammann staff and dealer personnel, again led by experts from across the
IMIESA May 2018
Ammann Group. We now plan to run another training session in South Africa during Q3 2018. We will also be sending a technical and sales team to the upcoming Ammann Group Africa Middle East workshop in 2018. Every Ammann member is required to be totally proficient in their field, and this translates into exceptional customer service. The same applies to ELB Equipment personnel. ELB, founded in 1913, is a highly respected company and an ideal fit for Ammann.
What is the Ammann Group’s strategic vision for South Africa? Effective from January 2018, Ammann South Africa became part of the Africa Middle East hub. This provides South Africa with a strong support system, which will drive Ammann’s regional expansion plans in Southern Africa, as well as further afield on the continent. South Africa and Africa have been identified as key growth markets for the group.
The Ammann Group has evolved into a sales-focused business, with a dedicated Direct Sales Division, which is the frontline for dealer and customer interfaces. While we predominately operate worldwide through a dealer network, we also provide a factory-to-customer service for package deals. Locally, Ammann South Africa has direct responsibility for asphalt and cement plants, while sales and after-sales for the Ammann machine range are handled exclusively by ELB Equipment.
What is the market uptake for asphalt plants? We’re pleased with the progress made to date. In April 2018, we sold a ValuTec 140 batch plant to a black-empowerment company based in Polokwane, along with two paving trains, comprising AV70X, AP240 and ARX26 compactors, and two AFW 350 pavers. This is our first
An Ammann ARS122 soil compactor produced at the factory in Ahmedabad, India
ValueTec 140 sale in South Africa and thus represents a major milestone for us. The ValueTec 140 is the flagship in the range, which is manufactured in India for worldwide export. Another significant aspect of this sale is that the deal was concluded via the Industrial Development Corporation. We expect this to become more common going forward as financial institutions increasingly invest in the future of SME contractor development. Another recent sale was concluded
Delegates attending a training campus for Ammann staff and ELB Equipment personnel in November 2017
with Tzoneva at its facility in Rustenburg. This is a Prime 140 plant, which has been specified with high-tech features to meet exceptionally high recycled asphalt requirements. Produced by Ammann in Brazil with approximately 40% local content. All of the accessories fitted to Tzoneva’s unit were sourced from South African manufacturers, representing approximately half of the plant’s value. This is in line with Ammann’s commitment to supporting local content fabrication. However, the final quality meets our exacting OEM standards. This is now the sixth Prime 140 unit sold in South Africa. One of its advantages is that the plant is semi-mobile, so it does not require a foundation. These plants are designed to be broken down, shipped in sections and then reassembled on another site when required.
There are also a number of unique features. These include the hot storage and drag slat set-up. The drag slat transfers the asphalt from the drum up to the hot storage bin. Based on customer feedback, we’ve remodelled the drag slat life significantly to accommodate wear parts such as buckets and chains. On the latest unit, we are anticipating up to 250 000 t of wear life on components.
How is your sales strategy evolving? Our research indicates that there is strong demand for rent-to-buy options when it comes to asphalt plant acquisitions, and this applies to both top-tier, as well as mediumsized and emerging contactors. So we’ve taken the decision to launch this offering and will be fielding a new CounterFlow 120 as the starting point. We are now working on a project to make
this plant road legal by fixing the unit onto a compliant trailer configuration. This will be a must for rental requirements. We are also considering pure rental on selected paving units.
What motivated your decision to move to new offices? We’d outgrown our previous facility, plus we also needed to centralise our parts warehousing and workshop operations under one roof. This led to the decision to relocate to our new head office in Benoni towards the end of 2017. We have plant parts available on site for all model of plants at our new, integrated warehouse, which underscores our after-sales commitment. In addition, we have five dedicated asphalt plant technicians trained to provide comprehensive advice and in-field maintenance.
Ammann recently unveiled its new factory in India. What’s the significance?
Customers view the Apollo Counter Flow 90 plant at Instant Tar’s facility
Back in 2013, Ammann entered the Indian market following a joint venture with Apollo, the country’s foremost brand for asphalt plants and machines. Ammann has now taken this a step further by investing €85 million (R1.25 billion) in a major remodeling and upgrade of Apollo’s Ahmedabad fabrication centre, situated in western India. During April, we took a South African customer group to Ahmedabad for a Techno Day during its official opening.
This is a very exciting development and we will be introducing new premium products locally from Ahmedabad during Q3 and Q4 2018. This includes the ARS122 single-drum 10 t soil compactor. These Ammann-branded products from India will be competitively priced while meeting the exacting global manufacturing standards of the group.
What does the future hold? We’ve taken the Ammann brand in South Africa (with regards to specific products) from 2% to a market share of around 13% in three years. In some cases, we dominate. For example, we have a significant market share for walk-behind rollers in our specific class. So we’re definitely moving in the right direction. The emerging contractor market is one of our niche focus areas since this is a government priority for future procurement spending. We’re here to support their growth with the best plant and machine match, backed by our technical expertise and training programmes. In Q2, we plan to run a customer workshop on asphalt plants, led by factory trainers. Going forward, our success will continue to be built on the strength of our exceptional Ammann and ELB Equipment team.
IMIESA May 2018
IMIESA speaks to Tumelo Gopane, managing director, East Rand Water Care Company (ERWAT), about the company’s future strategy and its pivotal role in changing the landscape of wastewater treatment in South Africa.
ome to more than 3.5 million residents, the City of Ekurhuleni is Gauteng’s third largest metro and a strategically important one, with its economy largely driven by agriculture, manufacturing and mining. Ekurhuleni’s approved Aerotropolis Master Plan is also strategically important, driving the vision of becoming an Aerotropolis City. Within this framework, ERWAT is vital to the city’s function, currently operating 19 wastewater care works and employing some of the most experienced engineers, scientists and technicians in this complex field. ERWAT permanently
IMIESA May 2018
ERWAT shares new thoughts on wastewater
runs plants that release between 800 MLD to 1 000 MLD, depending on the season. “ERWAT is a recognised leader and our wish is to collaborate with all stakeholders in order to share the knowledge we’ve gained over the years in addressing the roll-out of wastewater infrastructure, operations and maintenance, and new construction,” Gopane explains. “Some three years ago, for example, ERWAT conducted an assessment on all of Limpopo’s wastewater treatment plants at the request of the Limpopo Department of Cooperative Governance and Traditional Affairs (CoGTA).” Currently, a fair number of wastewater plants in South Africa are not performing as well as they should. Where discharged effluent is not meeting ideal standards, this
has a knock-on effect, increasing the cost of downstream water purification. “We’re here to collaborate in addressing the situation, as well as highlight and emphasise the nationwide backlog on sanitation, which is frequently one of the more neglected areas in the infrastructure mix, as the focus is largely on potable drinking water.”
City Managers Forum A positive step in this direction is the reestablishment of the City Water Managers Forum, an initiative led by the South African Local Government Association (Salga) and the Department of Water and Sanitation (DWS). Hosted in Cape Town during March 2018, the forum was attended by water and sanitation department HODs from across the eight metros, in addition to ERWAT and Johannesburg Water, and provided a great platform for engagement. “Everyone who extracts from a natural water source, like a river, pays a levy of around R1 per kiloliter to the DWS, which is then allocated for dam maintenance and construction,” he continues. “If this money and other infrastructure grants can be pooled, a far more integrated approach could be achieved by infrastructure planning executives. By developing heat maps for the country, we will then clearly define priority areas. We plan to discuss this further at the next meeting, where we will formulate action plans and timelines.
“We’d also welcome the participation of the Trans Caledon Tunnel Authority, since its involvement in financing and implementing mega bulk water schemes – like the first two phases of the Lesotho Highlands Water Project – is an essential part of the process in ensuring that metros and other municipalities have the necessary dams and future storage requirements to meet urban expansion and mitigate the drought situation.” At a higher level, the premier of Gauteng plans to set up a ‘water war room’, where ERWAT, along with other key stakeholders, will participate. “We’ve also been in discussions with the Municipal Infrastructure Support Agent, and have stated that ERWAT is available to collaborate with the implementation of CoGTA’s Local Government Turnaround Strategy on water and wastewater,” he explains.
Urbanisation and sanitation In an ideal world, planning and infrastructure roll-outs should be in advance of forecasted trends, but the rate of urbanisation in South Africa, like most of the world, is unprecedented. Ekurhuleni has over 100 informal settlements, and the number is set to grow. That puts an enormous strain on existing infrastructure and the city’s human settlements programme. “Building wastewater facilities, pipelines and pump stations for these settlements cannot happen overnight, largely due to financial constraints. Therefore, we’re looking at more realistic alternatives, like package plants, which are far faster and more affordable to deploy than conventional treatment works,” Gopane expands. “Plus they should ideally replace VIP (ventilated improved pit) toilets, which were always intended to be a temporary solution. Tumelo Gopane, managing director, ERWAT
VIPs cost the city millions to service annually and impact negatively on quality of life.” Package plants also have the advantage of being decentralised, ‘off-the-grid’ solutions that occupy small site footprints, making them well suited for installation within a congested township setting. Gopane also argues that a decentralised, package plant approach should be considered for new developments in general, including industrial zones. “Otherwise, it will be very challenging to raise the capital to address the current backlogs and provide for future requirements,” he states.
19 ERWAT is currently operating 19 wastewater treatment works in the City of Ekurhuleni
Infrastructure assessments In the past financial year, commencing 1 July 2017, original equipment manufacturers (OEMs) were tasked with conducting infrastructure assessments at all ERWAT plants to evaluate future maintenance and replacement needs on critical equipment and machinery, like pumps, electric motors, transformers and biofilters. Ekurhuleni’s 250-plus pumpstations, maintained by ERWAT, have also been rigorously inspected. This maintenance philosophy of OEMs continuously ascertaining how their equipment is performing over its lifecycle ties in with ERWAT’s decision to appoint Aurecon, which will be responsible for developing an asset management policy strategy. This will include the development of standards and specifications. Gopane says that ERWAT’s asset management approach will be shared with the industry.
ERWAT projects Within its own organisation, ERWAT has embarked on various upgrade initiatives, as well as longer-term plans to rationalise
800 MLD to 1 000 MLD
ERWAT permanently runs plants that release between 800 MLD to 1 000 MLD, depending on the season
IMIESA May 2018
Industry Insight its treatment plants down Tsakane is currently being from the current 19 to around 9. commissioned and features the use The estimated cost of of Bluewater Bio International’s rationalising the plants is proprietary Hybacs activated sludge around R7 billion over an envisaged five-year period. process, supplied and supported This will enable ERWAT’s locally by Headstream Water remaining plants to be upgraded for a further 50-year capacity, based on a forecasted pop- system is running optimally, using 60% of the ulation and industrial growth rate of between electricity for the same quantity of wastewater 3% to 4% per annum. and a third of the physical footprint. Three of the plants – namely Welgedacht, Tsakane, and Hartebeestfontein – are PPP opportunities presently being revamped. The project at ERWAT is currently researching the best way Welgedacht has been completed, while work to attract the necessary funding. “We’re at Hartbeesfontein is expected to be finalised talking to the Development Bank of Southern within the next four months. Hartebeestfontein Africa to see if we can attain loans on is being equipped with Nereda, an advanced, the back of grants and operating savings,” proprietary biological wastewater treatment he continues. Other approaches being investigated technology from Royal HaskoningDHV. In the meantime, Tsakane is currently include establishing public-private partnerbeing commissioned and features the use ships (PPPs) based on the build, own, operate of Bluewater Bio International’s proprietary and transfer model. For industrial customHybacs activated sludge process, supplied ers, this would include selling reused water. and supported locally by Headstream Water. Gopane points out that ERWAT’s Waterval ERWAT reports that the Hybacs ‘plug-and-play’ plant, which serves an almost 95% industrial
client base, would be well suited for a PPP and could be ring-fenced to guarantee a return on investment. Outside Ekurhuleni, additional funding could potentially also be sourced by assisting other municipalities and by increasing ERWAT’s private sector business where it already manages the wastewater needs of a number of blue-chip FMCG clients. Mining is the next sector being targeted. At the 2018 Investing in African Mining Indaba, ERWAT’s stand attracted a number of positive enquiries from local mining houses, as well as operations in countries like Zambia and the DRC. “Our vision is for ERWAT to become the entity supporting wastewater across South Africa and beyond. We are already doing this in a fragmented manner, but we now plan to coordinate it from a Salga viewpoint to ensure that every citizen has access to world-class sanitation,” Gopane concludes.
WHO ARE WE We are an innovative environmental company with a focus on providing turnkey water and wastewater treatment solutions to provide practical and sustainable solutions for the efﬁcient use of our water resources
WHAT WE OFFER Headstream water offers turnkey Water & wastewater treatment solutions: • Needs assessment • Technology supply • Design & manufacture • Installation & maintenance • Operation & ﬁnance
TECHNOLOGY Our core technology is HYBACS (HYBrid ACtivated Sludge), a proven and innovative biological wastewater treatment technology ideally suited to increasing the capacity of Activated Sludge Wastewater Treatment Plants and improving overall treatment performance
The cost effective solution for overloaded activated sludge plants Doubling of treatment capacity can be achieved within the existing WWTW footprint with limited civil works leading to signiﬁcant cost and time savings. • • • • • •
CAPEX savings of up to 50% on upgrades to existing STPs Ideal retroﬁt to existing WWTWs Up to 30% reduction in energy use per Mℓ/d treated Simple operation and maintenance Fast and simple installation and commissioning Scalable: small scale on site package plants to >100Mℓ/d
Recently selected by ERWAT for the increase in treatment capacity at Tsakane WWTW from 11Mℓ/d 20Mℓ/d • • • • •
9Mℓ/d increase in treatment capacity Signiﬁcant cost savings Minimal civil construction Minimal pant disruption No increase in plant footprint
WEB: www.headstreamwater.co.za TELL: 011 886 7805 EMAIL: email@example.com
READ INSIDE Taking a holistic approach
City of Ekurhuleni over view
Accelerating municipal water infrastructure
Why is a full smar t water solution the right choice for Africa?
IN THE HOT SEAT â€œOur pumping technology keeps getting better every year, thanks to a major investment in research and development across all product lines.â€? Andrew Brunette Team Leader: Wastewater, Grundfos
IMIESA May 2018
Taking a holistic approach
Celebrating 16 years in 2018, Lekwa Consulting Engineers shares its future vision for megacities. It works best with a professional resource team approach (PRT) and turnkey project delivery.
ekwa’s focus on mainstream civil infrastructure consulting and construction management is rapidly evolving, as it positions the business to meet the multifaceted requirements of government. The firm’s extensive experience in human settlement developments is a prime example, where scientific project and programme management tools are vital. That’s now backed by Lekwa’s investment in drone technology to monitor, analyse and verify work in progress. “Lekwa entered the affordable housing sector in 2006 when the Gauteng Department of Human Settlements opened up the market to PRTs,” explains Kibiti Ntshumaelo, managing director, Lekwa. “We were one of the consortium of firms selected.” Within the PRT model, one principal agent is responsible for the entire professional team. For government agencies, dealing with the principal agent provides a one-stop solution, significantly streamlining the
procurement process, as well as risk management and professional responsibility. “Then, in terms of project roll-out, having a design and construction team working together ensures a highly efficient holistic methodology,” he points out. The PRT approach has provided Lekwa with invaluable experience in the management of turnkey projects, which has become an area of specialisation. Lekwa’s integrated approach encompasses environmental impact assessments (EIAs), town planning, bulk water and sanitation services, roads, electrification, public lighting, geotechnical investigations, foundation designs, and building roll-out – through collaboration with specialists within the built environment. Another important element is the provision of beneficiary profiling and administration to ensure that future homeowners are correctly registered on the National Housing Subsidy System (HSS). “We’ve perfected the preplanning, planning, and detail design phases of township establishments as the PRT lead on multidisciplinary teams,” he
“We’ve perfected the preplanning, planning, and detail design phases of township establishments as the PRT lead on multidisciplinary teams.” Kibiti Ntshumaelo, Pr Eng, managing director, Lekwa Consulting Engineers
IMIESA May 2018
explains. “We’re now recognised as experts in the sector and, with the subsidy quantum steadily increasing, we are able to create better, habitable spaces and more complex structures. It’s a wonderful experience to see the change we’re making in people’s lives when we hand over the keys to their new home.” Lekwa has received numerous awards for excellence. These include recognition for the Nellmapius Ext 22 township development in the City of Tshwane, which received a Bronze in Sustainable Development at the Gauteng Premier’s Service Excellence Awards 2017 and was further awarded the best Community project in the SAICE Johannesburg branch in 2017. “We’ve studied the history of housing in South Africa pre- and post-1994, including earlier examples of RDP implementation, where quality control was not always adhered to,” he continues. “Also, it’s essential that current and future developments address the challenges of apartheid spatial planning for projects that built settlements outside major urban areas. Town planning now and in the future must ensure that townships are close to employment opportunities and fully integrated in line with government’s megacity vision. Road networks and bulk services must also cater for future township expansion.” “This master planning by the metros to form socio-economic corridors naturally lends itself to a multidisciplinary approach and puts an end to
Ekurhuleni | Cover Story the ‘triple 40 scenario’ where RDP houses were only 40 m2, situated 40km from work, and where residents had to spend 40% or more of their income on public transport.”
Quality control Lekwa has rigorous quality management systems in place for both design and construction, ensuring that contactors build infrastructure to the highest and acceptable standards, without any shortcuts. To achieve this, Lekwa personnel are present on-site at all times, providing the right level of supervision. This also provides an excellent opportunity for community training initiatives, where Lekwa is actively involved, and mentorship programmes for candidate professionals, qualifying small enterprise (QSE) consulting firms, as well as municipal engineers. As part of this process, a number of Lekwa’s staff are registered mentors with the Engineering Council of South Africa (ECSA). “The management of budgets, production capability and quality all need to be in synch to achieve the best result,” Ntshumaelo points out. “By sticking to the original design specification, and implementing strict project management, the risk of cost overruns is minimised. We understand the process well. For instance, Lekwa is the appointed programme manager for the Social Housing Regulatory Authority (SHRA).” Currently, Lekwa is managing 16 social housing projects for the SHRA. The most recently completed is Thembelihle Village in Tshwane, which was officially unveiled in April 2018.
Current projects Alongside human settlements, Lekwa’s multifaceted team works in parallel on a wide range of other infrastructure projects. A case in point is a current contract for the City of Ekurhuleni’s Solid Waste Department, which entails the design of a hazardous cell at Platkop Landfill site. This cell will handle the safe disposal of materials like asbestos. Lekwa is currently busy with the EIA process and ensuing approval by the Department of Water and Sanitation. The design will extend the landfill’s working life for the disposal of hazardous waste by around 33 years.
“Our investment in drones is part of our mission to ensure we’re geared up for Industry 4.0 and worldclass design and construction management.” Meanwhile, in the roads sector, Lekwa is busy with a project for Moqhaka Local Municipality in Kroonstad’s Seisoville township. The scope entails the design of a concrete-block-paved bus route that will link two communities. Lekwa is currently investigating a water and sanitation project opportunity in the Free State town of Steynsrus, and is currently working on a disaster management centre in Volksrust, Mpumalanga, where the firm is part of the PRT team. Other design work includes a multipurpose centre in Ladysmith, KwaZulu-Natal. “These projects represent our typical public sector involvement, alongside which we continue to develop in other areas. For example, we have extensive experience in the agriculture segment for both public and private clients,” Ntshumaelo explains.” Examples include broiler facilities and roads for the Mpumalanga Department of Agriculture, Rural Development, Land and Environmental Affairs. Returning to human settlements, Lekwa is currently the engineer on the KwaZenzele megaproject in Endicott, some 16 km from Springs, while the final stages of Nellmapius Ext 22 are expected to be completed by August 2018.
recent State of the City Address, Cllr Mzwandile Masina, executive mayor, City of Ekurhuleni, referred to multibillion-rand capex investment inflows. The city has also launched three of its six envisaged megaprojects, working with the Gauteng Department of Human Settlements. These comprise Leeuwport (19 453), John Dube (10 265) and Daggafontein (17 180). “We hope to get the opportunity to add real value, and we have previous design and construction experience in dolomitic zones, which are common within Ekurhuleni,” adds Ntshumaelo. “Our investment in drones is part of our mission to ensure we’re geared up for Industry 4.0 and world-class design and construction management. We’ve already received our Air Service Licence (ASL) from the Department of Transportation. Our next step is to obtain our Remote Operator Certificate and Letter of Approval from the South African Civil Aviation Authority (SACAA). That will then revolutionise how we carry out projects. “As they say, ‘the sky’s the limit’, and we see an exciting future for Lekwa as we drill down into our areas of specialisation,” Ntshumaelo concludes.
Ekurhuleni developments Headquartered in Alberton, Lekwa’s home base is in Ekurhuleni, a city with major expansion plans and a wide spectrum of infrastructure opportunities, including the Aerotropolis Master Plan. During the
IMIESA May 2018
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State of the City | Ekurhuleni
An airport city unfolds
Agriculture, manufacturing and mining are the mainstays of Ekurhuleni’s economy, and the city’s vision is an exciting and ambitious one.
uring the recent State of the City Address in March 2018, Cllr Mzwandile Masina, executive mayor for the City of Ekurhuleni, outlined a constructive approach for Gauteng’s second largest metro, bolstered by substantial capital investment inflows. “We have increased capex from R4.1 billion to R5.1 billion, and we will continue ramping it up in the outer years,” said Masina. “The target is to reach R10 billion by 2021.” Moody’s has maintained the city’s current rating status at Baa3/Aaa.za. “Our capex was sitting at 87% when we took over the administration. I’m happy to report that in the 2016/17 financial year, we recorded 91.4%. Looking at our performance, I’m confident that 2017/18 will further improve going forward. The grant expenditure was at 82% and is currently at 97%, meaning we are not returning large sums of money to National Treasury that were meant for infrastructure.” The city’s approved Aerotropolis Master Plan maps out major development opportunities radiating from O.R. Tambo International Airport and its growing industrial and logistics hub network. Some R7.2 billion worth of inward investment has been confirmed for diverse projects that include commuter rail service upgrades, residential housing and the Tambo-Springs inland port development. In order to enable these investments, Masina says the city identified the need to expedite and facilitate the installation of bulk infrastructure (as provided for in Spluma in terms of sections 49(2) and 49(5)). “We have since budgeted for bulk infrastructure for ‘developmentready’ projects,” he said. To support Expanded Public Works Programme objectives, the city’s goal is to ensure that a minimum of 30% of project values are localised to the ward and/or area where they are implemented.
Clearing committee To facilitate the overall process, Ekurhuleni plans to establish the Central Investment Clearing Committee. The intention is to reduce approval turnaround times in areas like land zoning, building applications and bulk infrastructure availability. This committee will also assist in streamlining investment applications when it comes to compliance issues. Additionally, the city plans to introduce incentive schemes. According to Masina, these will “combine rate rebates, negotiated tax holidays and joint applications to attract investment from public institutions for projects from R10 million and above.” The coordination hub will be the proposed Ekurhuleni Investment Agency. With industrial growth comes an allied surge in residential demand, which is one of the key priority areas for Ekurhuleni. Leeuwport (19 453 units), John Dube (10 265) and Daggafontein (17 180) are the first of the six mega housing projects launched.
IMIESA May 2018
“Our programme to upgrade and invest in infrastructure has commenced. We have 28 consultants planning for over 2 000 km of water and sewer pipes for upgrading, replacement and extension,” Masina pointed out. “And we’re constructing 20 pump stations and decommissioning 50 redundant ones.” On top of this, Ekurhuleni added 20 Mℓ of water storage capacity and 61 km of new roads last year. Approximately 100 km of the existing road network was rehabilitated during the same period. There are also a number of catalytic road infrastructure projects in the pipeline, including the Aerotropolis Road Network Master Plan. A key component is the planned construction of PWV15 – a link between the R21 and N12 that will meet ongoing urban and industrial expansion. Cllr Mzwandile Masina, executive mayor, City of Ekurhuleni
Ekurhuleni | Hot Seat
Pumping technology perfected
Self contained immersible sewage pumps
Within the OEM market, what sets Grundfos apart from its competitors? AB Our unique technology and technical backup is a key differentiating factor. We have a design centre at our headquarters in Denmark, which is dedicated to developing, testing and refining our product offering. We offer wastewater pumps ranging from 0.9 kW to 520 kW and they meet every conceivable requirement, from low to high flows, and low to high pressures. In fact, our pumping technology keeps getting better every year, thanks to a major investment in research and development across all product lines. In addition to pumps, for example, we’re Andrew Brunette, team leader: Wastewater, Grundfos
IMIESA May 2018
IMIESA talks to Andrew Brunette, team leader: Wastewater, Grundfos, about current solutions and trends in the field where there is a major focus on streamlining efficiencies through product innovation. making great strides in terms about 84%, but their grit and sand of smart technologies when it capabilities are a lot lower due to comes to controllers, and with the design tolerances. our impeller designs. Challenges such as sealing For the wastewater market, against backflow, vibrations, we field two main abrasive wear and clogging impeller options, have all been mastered namely the tried with the S-tube, which is and tested vortex the only wastewater impeller impeller, and that doesn’t compromise the newer and hydraulic efficiency or free revolutionary S-tube passage through the pump. channel impeller. Our smart controllers also While vortex pass on major savings, impellers are older automatically configuring and less efficient adaptive flows and than their channel heads to suit pump fluid counterparts, they volumes. Additionally, all still have their place controllers are designed because they can to communicate with handle higher solids, the Grundfos Remote rags, sand and grit, Management (GRM). with a minimised Prefabricated pumping station Pump stations are risk of clogging. A critical to the process. blockage in a pump What are some of the station is definitely something to developments here? avoid. This makes vortex impellers This is a core area of a good fit for many emerging specialisation and we offer the market treatment facilities that full range of services, from design lack adequate screening systems. to commissioning. Grundfos has S-tube impellers handle solids up developed simulation programmes to 160 mm with an efficiency of
to assist consulting engineers with pump station designs to ensure the right set-up. After that, we provide a computational fluid dynamics report to verify that the inlet and outlet set-up for the proposed pump station are in the right places; that the flow is travelling in the right direction; and that the inflow doesn’t travel directly into the pump inlet, thereby preventing possible cavitation.
What are the trends when it comes to pump stations? Grundfos’ ‘plug-and-play’ prefabricated HDPE pumping stations (also known as lift stations) are popular internationally, but still relatively new in South Africa. They provide an intelligent solution that simplifies pump pit management. We also assist here with design and commissioning. These pumping stations are ideal for the confined footprints typically found in high-density urban environments, while also meeting the diverse needs of privately owned treatment works. All the necessary components, such as piping, valves, pumps
Ekurhuleni | Hot Seat
and controllers are built into the consider future use. Also, as I’ve modular unit. All the contractor just mentioned, pumps seldom needs to do is drill the inlet and run at maximum, so you end up outlet holes, make the pipework wasting a lot of energy. connections, and then Using the right turn on the power. accessories also S-Tube impeller The pump station makes a big difference, operates autonomously; especially in minimising one of the key features blockages. A good is its ‘flush and example is the installation reverse’ anti-clogging of a mixer to keep functionality. solids in suspension. That will prevent solid Where do you concentrations from source your overloading the impeller in electric motors? pump stations. Grundfos is one of the few Another big focus is on OEMs to manufacture electric fine bubble aeration. This is a very motors for its own exclusive use. efficient method of introducing On the clean water pump range, oxygen into the mix, as opposed to this includes Grundfos-developed conventional vertical shaft aerators IE5-rated motors. IE5 is the at a wastewater treatment works. highest energy-efficiency level Is maintenance a for electric motors. All Grundfos burning issue? MGE motors, from 0.75 kW to Yes, it is a big factor. A wastewater 11 kW, have attained IE5 status, pumping station is maintenancedelivering considerable energy intensive. You can install the savings and exceptional best product solution but without pump performance. maintenance, any Pumps across the range pump will block, come equipped with integrated with the ensuing variable-speed drives (VSDs), risk of sewage which automatically regulate build-up and running speeds according to overflow. the flow and load. Grundfos has Our dedicated developed its own series of CUE smart controls frequency inverters preset with for wastewater our OEM pump parameters, and CU362 Smart are intended to an easy five-step startup. Noncontroller prevent these and Grundfos VSDs can have up to 20 other scenarios by providing parameters that need to be setup, predictive and preventative tools which is far more taxing. for maintenance engineers. We Non-VSD-equipped pumps run can connect any pump station at full speed all the time, despite to the GRM network, which then the fact that the actual power intelligently communicates with requirement might be far lower. these controllers. This enables For example, most pumps only near-real-time monitoring, need to work at 30% to 50% of condition assessment and their design capacity most of reporting on pump station the time. operating parameters, together Can you comment with alarms and failure alerts. All on energythis information is tracked by a efficiency initiatives? dedicated control room team at It starts with choosing the right our Johannesburg head office. pump for the right duty. In the Many of our customers have past, pump set-ups were often entered into service-level designed on the maximum agreements (SLAs), which are output required, but didn’t always proving increasingly popular with
Darvill Wastewater Treatment Works, which is currently under construction, houses large wastewater transfer pumps from Grundfos’ S range, flow recycle pumps, wash water and booster pumps
public and private sector clients, both on the wastewater side of our business, as well as in our Building Division for booster pumps. Some of our mega farming clients are also on board. Where notifications that require a maintenance intervention are received, a Grundfos service team is dispatched. Customers who do not enter into SLAs, because they want to carry out their own maintenance, can also use the network for the same purpose, which is accessible via PC or a mobile app. We see maintenance outsourcing as a growing business and municipalities should definitely consider SLAs on pump stations and mechanical equipment in general. A focus on predictive maintenance is essential to ensure uninterrupted operations. Grundfos is currently in discussions with a number of consulting engineering firms and contractors tendering on operations and maintenance contracts for municipal treatment works.
What is your municipal experience to date? As an OEM, we mostly work through third parties, namely consultants and contractors, where we have been successful in growing our municipal market share. Recent projects include the supply of integrated product solutions for the East Rand Water Care Company’s Hartebeestfontein plant. Our technologies used range from pumping, dosing and disinfection to aeration and mixing – essentially covering the full treatment process from the
inlet works to the final effluent discharge point. Another project is Umgeni Water’s Darvill Wastewater Treatment Works, which is currently under construction. The scope here includes the supply of large wastewater transfer pumps from Grundfos’ S range, flow recycle pumps, wash water and booster pumps. Our products and experience can be applied across all sectors. For example, being part of the local acid mine drainage projects. The key point to emphasis, is that our products and technologies can be utilised for all water and wastewater applications and we work with the industry to customise optimal solutions.
IMIESA May 2018
Accelerating municipal water infrastructure
Building in precast is a proven and highly efficient technique for reservoir construction, passing on major time and cost savings, says industry leader Corestruc.
ybrid-concrete construction many reservoirs built over the years that (HCC) has allowed also feature a significant precast concrete international professional component. This approach has played a teams to significantly prominent part in assisting local authorities accelerate the delivery of civil infrastructure, to significantly speed up the delivery of this and South Africa is gradually following critical service to their constituencies. suit as policymakers Krugersburg explore faster and Corestruc’s more ef ficient precast system A case in point is the rapid completion of the 50 Mℓ methods. Krugersburg reser voir This is especially can be programmed in as little as 11 months the case for municipal concurrently with to cater for peak potable infrastructure where other activities and, water demand in Polokwane project efficiencies during the 2010 FIFA are being achieved therefore, does not World Cup. by merging the best restrict multiple Months were shaved off in conventional activities on sites.” the construction programme in-situ practices with the design and construction of precast by constructing the roof from precast concrete structures. Sound examples of elements, the most costly, complex and successful HCC projects locally include the time-consuming aspect of the entire build.
IMIESA May 2018
The roof structure of the 35 Mℓ Katlehong Reservoir was completed in only 13 days
The 5 080 m2 precast concrete roof structure comprises pre-stressed 250 mm thick hollow-core slabs with a span of 11.4 m between beam centres. It is supported by 50 precast pre-stressed concrete I-beams with a span of 8.4 m between column centres. The beams, in turn, are supported by pre-stressed precast columns ranging between 9 m and 11.3 m in length. Corestruc designed and installed the roof structure on behalf of the professional team, which comprised civil and structural engineers VBL Consulting Engineers and Ingerop South Africa, as well as Yarena Civils, the main contractor. This is just one of more than 50 reservoir construction
projects of varying sizes that Corestruc has completed on behalf of local municipalities. The company’s skills and capabilities span the design and manufacture of the high-quality system components through to the swift and precise installation of the roof structure.
Katlehong More recently, Corestruc also participated in a 35 Mℓ reservoir project in Katlehong on behalf of Ekuhurleni Metropolitan Municipality. The company became involved during the early design phases when it was decided to use a precast concrete roof structure to fast-track construction. It was completed in only 13 days, far exceeding the main contractors’ initial expectation of allowing 26 weeks for the construction of the columns and roof deck. The significant time savings were achieved by eliminating the process of dismantling and removing tonnes of supporting scaffolding. The roof structure comprised 3 500 m2 of hollow-core slabs, each up to 250 mm deep, supported by 16 columns and 18 beams. A total of 2 000 m2 of precast items were installed in as little as eight working days, with the company achieving tolerances of about 20 mm at heights of 15 m.
Mafenya Corestruc has maintained similar high productivity and accuracy levels on other flagship projects. This includes the 50 Mℓ Mafenya reservoir, which received a commendation at the 2017 Fulton Awards for Excellence in the Innovation in Concrete category. On this project, the company worked alongside M&D Construction to complete the reservoir for Magalies Water in as a little as 14 months. Its timely completion was critical for platinum mines in the area. The columns were constructed as a combination of an in situ stub with a precast element to achieve the desired height, and the roof planks were supported by a beam system that was tied to the top of the precast columns. To assist with drainage on C completion, the in M situ stubs
The 50 Mℓ Mafenya reservoir received a commendation at the 2017 Fulton Awards for Excellence in the Innovation in Concrete category
The 30 Mℓ Perskebult reservoir was completed on behalf of the Polokwane Municipality. The company worked alongside Yarena Civils on this project
were cast to align the camber of the roof. The entire system comprised 36 columns, 40 beams and 290 slabs, in addition to the coping system for finishing the roof edge.
EPWP Corestruc is also working alongside emerging contractors on smaller Expanded Public Works Programme projects, considering its proven track record in mitigating risk on these builds. Importantly, they also serve as sound examples of the important role precast concrete technologies play in complementing labour intensive projects. “Our specialist skills and capabilities augment those of the main contractor and the many unskilled members of communities that receive important training on these projects. The high quality of the final structure and its timely completion supports the accelerated roll-out of these projects, which are in line with government’s transformation and skills development agenda,” says Willie de Jager, Corestruc-105x148 - April.pdf 1 2017/04/05 9:50:40 AM managing director, Corestruc.
The 14 Mℓ Rustfontein reservoir is a sound example of Corestruc’s on-going involvement in smaller reservoir projects
IMIESA May 2018
Structa Technologyâ€™s Prestanks are hygienically safe, cost effective and a reliable way to store water for commercial sectors, private sectors and even for personalized storage. Choose from temporary or permanent erection at mines, powerstations, building sites, hospitals, water affairs,municipalities, rural communities and agriculture.
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Why is a full smart water solution the right choice for Africa? Smart technology and the Internet of Things (IoT) are taking the world by storm. In order to ensure the success of smart water initiatives and solve the water challenges in Africa, it is crucial for smart utilities to choose the right technology and equipment.
he recent drought has placed South Africa’s water situation squarely in the spotlight. Gerardt Viljoen, managing director, Sensus, believes South Africa needs to take a more holistic approach to the water cycle. “Not many people look at the big picture, which means looking at everything over time. National government needs to take this approach when dealing with our water resources and infrastructure,” says Viljoen. This entails monitoring the entire value chain. Being a brand of leading global water firm Xylem, Sensus is able to provide end-toend solutions for utilities using industryleading technology across the full water cycle. Xylem’s well-known global brands have served the water sector in over 150 countries for decades, producing highly
Water Pump Control & Data & Asset
efficient water technologies that use less energy, reduce asset life-cycle costs and provide environmental benefits to users and the communities in which they operate.
Secure connection As connectedness becomes the norm, it is vital that critical national infrastructure has a safe platform for connection. The FlexNet communication network is a power ful long-range radio system at the heart of Sensus’ advanced metering infrastructure (AMI) solutions. Unlike other IoT utility networks, FlexNet offers a dedicated radio spectrum that is protected by law from interference, thus ensuring reliability and protecting critical infrastructure from infiltration. As part of a full smart water solution, the FlexNet system enables smart meters
and sensors to securely and confidently transmit and receive near-real-time customer usage and infrastructure data. This improves business intelligence by allowing utilities to proactively manage their smart water networks. The system is also built on open standards and APIs for easy interface with third-party applications and platforms. Importantly, a full smart water solution – which combines technologies to monitor customer usage, improve asset management and reduce leakage in order to increase efficiencies within the utility – also allows users to plot and monitor their network efficiencies. “As soon as you know your network efficiencies, you know where you should focus your capital investment for infrastructure improvement,” says Viljoen. Using infrastructure condition management
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IMIESA May 2018
technology, Rand Water was able to save 90% on capital expenditure by conducting pipeline assessments. “On 100 km of pipeline, only 10 km needed to be replaced, saving Rand Water from having to replace a significant amount of infrastructure.”
Predictive technology A full smart water solution is able to supply equipment to ef fectively identify leaks and even predict where they will occur. South Africa’s non-revenue water sits at 41%, of which 35% is lost through leakage. With municipalities losing about 1 660 million m³ per year as a result, the applications for this technology are extensive.
Multiple pipe leakage indicators such as high-rate pressure sensors, hydrophones and flow meters installed at optimal locations, coupled with minute-by-minute data analytics, can be used to predict pipes that are likely to fail in the near future before bursts and fur ther damages occur.
Measure to manage Accurate meter readings are vital to effective water management. Notably, Sensus’ iPERL water meters have no moving parts, giving them up to three times the lifespan of conventional mechanical meters. These solid-state mechanical meters work on the electromagnetic principle and are currently the most accurate domestic meters in the world, reports Viljoen. The
iPERL meters are exceptionally popular in Saudi Arabia and Namibia, where fine sand particles create friction that wears down conventional meters. This does not affect iPERL meters, making them perfect for African countries with high sediment content in their water supplies. While mechanical meters lose roughly 1% of accuracy per annum, the iPERL will never lose its accuracy and is capable of detecting leaks of under 1 ℓ/h – like a dripping tap. The smart water meter comes equipped with smar t alarms, such as tamper alerts, and can assist in driving additional revenue from residential accounts, as well as ensure customer trust through increased accuracy. While metering is by no means a new concept, South Africa still sits with a high percentage of unmetered environments, says Viljoen. “Water is a scarce and finite resource and it is our reasonability to be good custodians. The best way do to this is by measuring so that we ensure we don’t waste it,” he concludes.
Solve water the smart way Water loss can be prevented with a fully integrated, end-to-end smart water solution, along with numerous other benefits: Increased efficiency by reducing leaks and pipe bursts
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Predict the lifespan of your assets
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With its acquisition of Sensus and Visenti, Xylem brings you best-in-class technology to create a full end-to-end smart water solution, delivering an unmatched offering with innovation in communications technologies, advanced metrology, sensors, data analytics and services. To find out how Sensus can help you to operate more efficiently, deliver high levels of customer service and conserve valuable resources, contactEMEA@xyleminc.com. Visit www.sensus.com for more information.
Improving water security for utilities
lanning for either too much and too little water is important, says Jason Hallowes, director, EkoSource. Not doing so can impact energy and industrial production, water quality and public safety. For the first time, with Mzansi Amanzi (Water South Africa), it is now possible to map and monitor a major proportion of dams across the country, continuously on a monthly interval, providing data that is invaluable to water management authorities and industries.
A first in water mapping Traditional methods of monitoring water resources tend to be very expensive and spatially limited. With technological advancements, a new range of solutions and satellite applications allow for much broader monitoring of assets. Free access to a number of space agencies’ archives via the cloud also provides access to large quantities of previously unavailable data, at a much faster access rate. “This has turned the industry upside down,” says Mark Thompson, director, GeoTerraImage. Taking advantage of this transformation, GeoTerraImage’s latest initiative – Mzanzi Amanzi, a monthly online water monitoring tool – offers national wall-to-wall coverage of South Africa’s surface water features. Using cloudbased satellite image data archives, combined with big data processing capabilities, the company has been able to generate spatially detailed information on the extent of all surface water features, from small farm dams to large impoundments, on a monthly basis. Their partnership with EkoSource will also provide the users with the ability to quantify water volumes in these dams. This will be introduced in the next development phase.
The case for satellite monitoring “The value of satellite technology lies in the identification of safety concerns such as flooding in specific areas. Additionally, it can provide insight into the overall water resources availability, and allow for planning of water deficits which could impact production in specific areas. Changes in water resources due to sedimentation and other elements are also a concern that this new technology can identify,” explains Hallowes. He adds that only approximately 300 major dams across South Africa are monitored – which is only a small portion of the country’s dams. “We can monitor 20 times this on a consistent basis,” says Hallowes. “The satellite technology approach gives a complete picture of the landscape,” adds Thompson. While the Department of Water and Sanitation only monitors a few hundred dams and relies largely on telemetry and installed equipment to monitor what is happening in catchments, satellite technology can provide accurate data across the board without the cost and time inefficiencies, he explains. EkoSource is now working to compile various other sources of remotely sensed information to generate projected stream flows to provide a better idea of what the dam levels will be in the short term. They are currently working with a company, Hydrologic, which is working with the South African Weather Service to acquire spatially consistent rainfall records from 1979 to 2017 across the country. Using this data, EkoSource is building predictive models that identify risks within the water cycle. While this data is useful for water resource management and planning, the big picture provided by Mzansi Amanzi can also assist with compliance monitoring. This
An inability to monitor a major portion of the country’s water resources impacts the ability to make sound decisions and adequately plan for risks.
includes identifying dams that should be registered with the Dam Safety Office, areas using large amounts of water for irrigation, incidents where water is being illegally extracted from rivers and streams, and inappropriate developments.
Making data available Mzansi Amanzi is a public domain website, with a subscription option available for users who would like to download and access more detailed surface water monthly coverages. However, Thompson believes sponsorships offers an ideal opportunity for larger organisations to assist in making this valuable data available to smaller organisations and the public. As South Africa faces increasing pressure on its water resources, the provision of these regular, high-cadence detailed surface water resource maps will support accurate and timeous monitoring of the status of local, regional and national water resources. For further info on Mzanzi Amanzi, visit www.water-southafrica.co.za or contact GeoTerraImage.
IMIESA May 2018
A case for membranes “Membrane technology can have a major impact on drinking water provision in subSaharan Africa.” This is the belief of Professor Lingam Pillay, associate professor, Stellenbosch University. By Danielle Petterson
embrane technology has become the preferred method of water treatment in many countries. However, it is still regarded as an emerging technology in sub-Saharan Africa and the uptake in municipalities for water treatment is very limited, says Pillay. Conventional water treatment processes work very well, provided coagulation and
VulAmanz Rural Water Filter project team flocculation done right and sedimentation and filtration are sufficiently designed to remove particle contaminants. However, this is often not the case, and membranes can therefore offer many benefits over traditional systems. According to Pillay, there has been a strong swing globally towards micro- and ultrafiltration for potable water production. This is largely because the quality produced by a membrane
The VulAmanz Rural Water Filter is a membrane filtration unit with a disinfection step contained in a bucket-like container, which can easily be stored
IMIESA May 2018
R&D TEAM: • Department of Process Engineering, Stellenbosch University • Department of Chemical Engineering, Durban University of Technology • Department of Polymer Science, Stellenbosch University • Centre of Excellence in Water and Energy, Savannah State University, USA • Department of Environmental Engineering, Asian Institute of Technology, Thailand • Gelvenor SPONSORS: • Water Research Commission of SA • Umgeni Water • Department of Science and Technology (Innovation for Rural Development Programme) DESIGNERS AND FABRICATORS: • SKEG • DDDXYZ
Water Utilities The RWF, which complies with WHO standards, will produce 20 ℓ in an hour on a clean membrane
is defined only by the membrane itself. It therefore provides very high and consistent product quality independent of both feed quality and the skills of the operator. Pillay believes that in developing countries like South Africa, the ability of membranes to provide consistent quality regardless of operator skills offers a major advantage. In a traditional plant, the quality relies greatly on the operator ensuring all processes are performed correctly. However, in many cases,
A truly decentralised solution
Table 1 Limpopo – implementation sites statistics Klipheuvel and Matatlane
Source of raw water Raw water quality Current treatment before consumption Number of VA-RWF units implemented Period for which units have been in operation (units handed out Feb – Sep 2016)
particularly in rural and peri-urban areas, the skills required to run conventional water treatment plants are not available. Membrane systems are also modular, offer much smaller footprints, and don’t require civil structures or as much piping as conventional systems. “This lends a membrane system to decentralised water provision very easily,” says Pillay. With South Africa’s rapidly changing demographics, a membrane system can be deployed where needed and easily expanded as demand increases due to its modular nature. “It also makes it feasible to have a large number of decentralised water treatment plants without reticulation over massive areas,” he adds.
Water from the Olifants River, piped to a reservoir, and gravity fed to standpipes in the villages Low turbidity; contamination by pathogens not known None 525 (25 V1 and 500 V2) 18 – 26 months
Table 2 Bizana – implementation sites statistics
Nine villages in Ward 9 of Bizana Local Municipality: Masebeni, Tshuze, Ndayini, Gwbeni, Mphetshwa, Zanokhanya, Bonda, Luphilisweni, Envis Source of raw water Various: springs, streams, etc. (sources change continuously) Raw water quality Low turbidity; previous analyses indicate contamination by pathogens Current treatment before consumption None Number of VA-RWF units implemented 500 14 – 19 months Period for which units have been in operation (units handed out October 2016 – February 2017)
Many of South Africa’s rural and peri-urban areas lack formal water infrastructure and the topography and wide spatial distribution of houses in these areas makes it extremely difficult to pipe treated water to these households. The result is people consuming pathogen-contaminated water directly from rivers and dams resulting in health complications. In response to this, a group of South African scientists have developed a membrane-based point-of-use household water treatment unit aimed at providing safe drinking water to offgrid rural communities. The resulting VulAmanz Rural Water Filter (VA-RWF) is a membrane filtration unit with a disinfection step contained in a bucket-like container, which can easily be stored. The system works as follows: 1. 25 ℓ of raw water is collected from a local source. 2. The user adds three drops of hypochlorite
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Threewaterskloof Dam catchments (H60B & H60C): Surface water (ha)
2 923 ha a loss of
Includes all surface water features: natural, man-made, seasonal and permanent, as observed each month www.geoterraimage.com
Max water area for the last 6 months:
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1 000 ha water in
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Current water extent, Jan 2018
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That’s a total area reduction equal to 1 000 rugby fields
Improving Quality of Life and Enhancing Sustainable Economic Development
Umgeni Water is a public entity established in 1974 to provide water services water supply and sanitation services - to other water services institutions in its service area. The organization operates in accordance with the Water Services Act (Act 108 of 1997) and the Public Finance Management Act (Act1 of 1999), amongst others, and categorized as a National Government Business Enterprise. Umgeni Water reports directly to the Department of Water and Sanitation through the Chairman of the Board and the Chief Executive. The Executive Authority of the water board is the Minister of Water and Sanitation.
Umgeni Water: Annual Report 2016/2017
310 Burger Street, Pietermaritzburg, 3201, Republic of South Africa / P.O Box 9, Pietermaritzburg, 3200, Republic of South Africa Tel: +27 (33) 341 1111 / Fax +27 (33) 341 1167 / Toll free: 0800 331 820 / Email: email@example.com / Web: www.umgeni.co.za
solution (thin bleach, such as Jik) to a 5 ℓ product vessel. 3. The raw water is poured into the raw water tank. The product tap is opened, and clean water is collected. The RWF, which complies with WHO standards, will produce 20 ℓ in an hour on a clean membrane, decreasing to 15 ℓ in an hour after two weeks. The RWF, which complies with WHO standards, will produce >100 ℓ/hour on a clean membrane, decreasing to around 50 ℓ/ hour after two weeks of operation without any cleaning, depending on the feedwater quality. The basis of the VA-RWF is a unique woven polyester microfiltration membrane, developed and produced in South Africa, which removes all suspended solids, colloids and most of the pathogenic bacteria. The disinfectant in the product vessel polishes the water and provides a residual disinfection capability. The apparent pore size of clean membranes is 1 μm to 3 μm. However, once filtration commences, the fouling layer removes particles <1 μm. The membrane has a lifespan of three to four years and is extremely robust. It is not destroyed by mechanical stresses or drying, is inexpensive, and can be easily cleaned without exotic chemicals. Notably, Pillay reports that the user response to the product has been phenomenally positive. It has already been demonstrated in the Eastern Cape and Limpopo, and various users have reported improved health. According to Pillay, this positive response is largely due to the fact that this technology was developed from the ground up. Social acceptance and user uptake are critical aspects of developmental interventions and big reasons why many POU water treatment systems have failed internationally. Traditional leaders in rural areas were consulted to establish their needs, rather than developing a technology based Membrane systems on perceptions and imposing this on rural are ideal for dwellers. An important decentralised potable aspect of the R&D was that students water production.” from rural areas were involved in the project. This enabled the technology to be developed from a user perspective, eventually leading to extremely high social acceptance and user uptake. The result is a product that provides safe drinking water to currently unserviced rural areas, thereby reducing health risks and breaking the downward spiral of poor health, poor education and poverty.
Making the shift Given the significant benefits of membrane systems, Pillay believes there is a necessity for a mind shift from the conventional technology, which hasn’t changed in many years, to much smaller membrane systems that provide higher water quality without the necessary skills. “Membrane systems are significantly less complex and significantly easier to operate,” says Pillay. He adds that membrane prices have nosedived in the last 10 years, making them comparable to, or possibly even better than, conventional systems, particularly because of the large civil costs associated with traditional treatment plants. “Our problem primarily comes down to a lack of knowledge and a lack of local experience. There are very few membrane scientists in South Africa or people who have been exposed to membranes. We need to have a mind shift,” he concludes.
IMIESA May 2018
WATER CONSERVATION AND STORAGE South Africa is a water-poor country, frequently prone to drought. It has therefore become crucial to line dams and reservoirs to prevent water loss and harvest rain water in the most eﬀective way. Thanks to 52 Years of experience, AQUATAN possesses the required engineering and supervision skills to provide expert installation and detailed engineering advice for any lining system. We have vast experience ranging from low technology small farm-dams to complex, major engineered multiple and composite GEOSYNTHETIC liner projects, complimented by our state-of-the-art real time AQ-CLOUDTM technologies and our ISO 9001:2008 accredited Program for Quality. AQUATAN does its own HDPE pipe welding on lining installation contracts where HDPE piping is an integral part of the system. This makes sense not only because of our vast experience in the specialised installation of GEOSYNTHETICS, but also our history of HDPE sheet manufacturing and in-depth knowledge of polymers. CONCRETE RESERVOIRS It is known that concrete reservoirs tend to crack due to settlement, joint failure and more over the years of their service life. Aquatan is able to line new concrete reservoirs as well as successfully rehabilitate aged reservoirs. Our proprietary HYPERLINER or Ethylene Vinyl Acetate (EVA), based on its amorphous molecular structure, has the ability not only to accommodate an enormous amount of movement when compared to similar products but also extend the life of a reservoir by 27 years and more. Its superior ﬂexibility, drape ability and ability to be chemically adhered to substrates makes it extremely suitable for waterprooﬁng of any reservoir far beyond less ﬂexible products such as HDPE or LLDPE. With Aquatan’s HYPERLINER (EVA) geomembrane we have cost eﬀectively given these old structures a new lease on life. This superior material, coupled with Aquatan’s vast experience in reservoir lining, IAGI Accredited installation teams and proprietary seaming equipment gives our clients conﬁdence they have become accustomed to. FLOATING COVER FOR RESERVOIRS Aquatan constructs ﬂoating covers to earth or concrete reservoirs on a turnkey basis with the latest generation Reinforced Polyoleﬁn Membranes now carrying a life expectancy of up to 30 years. These covers are applied to Potable Water Reservoirs, Molasses Storage Reservoirs and Chemical Containment Reservoirs to prevent pollution, evaporation as well as dilution of the stored liquid. PROUD MEMBERS
FOR MORE INFORMATION CONTACT Tel: +27(0)11 974 5271 Fax: +27(0)11 974 4111 E-mail: firstname.lastname@example.org or visit our website:
The creative use of an advanced membrane liner ensures a perfect seal, outstanding durability, and downstream water quality at one of Africa’s largest reservoirs.
s regards scale and scope, Umgeni Water’s 340 Mℓ Durban Heights Reser voir No. 3 is a distinctive structure and one that has stood the test of time since its construction in 1971. Internally, that’s largely due to the installation of a proprietary geomembrane lining system in 1991 to counter a serious leakage problem that was causing a daily water loss of some 300 kℓ . For close to 27 years, the liner has performed perfectly, but now needs a number of maintenance interventions. This will repair sections that have been subjected to minor impact damage caused by cladding tiles separating from the overhead cablesuspended precast concrete roof. This roof is supported by a 48.67 m high central cylindrical tower designed to be immersed to a height of 25.65 m from floor level to top water level, at full storage capacity. At this point, the top water level measures 272.31 m above sea level. The diameter of the reservoir is 167.64 m, and the vertical walls are supported on both sides by buttresses. The roof panel supporting cables were spanned from the top of the vertical perimeter wall to the top of the central cylindrical tower to protect the integrity of the submerged concrete structure. To keep it leak-free, the entire submerged surface area is protected by the installed membrane system, including the internal and external surfaces of the 11.28 m diameter central cylindrical tower, to just above the 25.65 m threshold to allow for freeboard. Prior to the membrane installation, however, a number of technical faults had emerged
Keeping Durban Heights watertight for 27 years Geomembranes were then investigated as and when a dam safety inspection confirmed an alternative and proved to be the best the leakage problem in 1991, an immediate approach. It was also a groundbreaking intervention was required. Water seepage decision given the reservoir’s size and depth. was eroding the reservoir’s supporting “At the time, it was probably one earthworks, increasing the risk of of the largest reservoirs in structural failure. In addition, the world to rely on a full significant corrosion geomembrane lining had occurred to the to keep the structure immersed internal 2 watertight,” explains concrete surfaces. Piet Meyer, managing An investigation at of Hyperliner 1500 was director, Aquatan the time by Stewart installed at Umgeni Water’s Lining Systems – the Sviridov & Oliver 340 Mℓ Durban Heights company responsible (SS&O) consulting Reservoir No. 3 for the installation. engineers revealed The product selected that the main cause of was Aquatan’s Hyperliner, the concrete degradation which is manufactured from a was due to the incoming water’s proprietary ethylene-vinyl acetate (EVA) low level of calcium hardness. The water material. Specially designed for covered was dissolving the lime contained in the structures, some of the key advantages of cementitious binder. EVA are its durability, tremendous flexibility, Remedial measures puncture resistance and drapability, being Meanwhile, the excessive water loss was a non-crystalline product, as well its traced to leaking joints and cracks in the excellent chemical resistance and drinking concrete caused by a subsidence that had water compatibility. occurred earlier in the life of the structure. The Prior to this installation, the Hyperliner engineers considered remedial measures, system had already been proved on several including the resealing of the joints and the landmark South African projects. These repair of the cracks. include the lining of the Drakensberg However, when it was considered that these Pumped Storage Scheme’s headrace tunnel, measures would have to be implemented the lining of the two machine shafts at the together with the watertight sealing of the Palmiet Hydroelectric Scheme, the lining of concrete surfaces by ‘paint-on’ systems, time the Huguenot Tunnel, as well as floor lining considerations excluded these options. for major thickener tanks employed by the mining industry. About 30 000 m2 of Hyperliner 1500 was installed at Durban Heights. The internal surfaces are complex in shape, with several changes in plane and diameter, making EVA
~30 000 m
An exterior view of Durban Heights Reservoir
IMIESA May 2018
the perfect choice. In order to complete the work as economically as possible, Aquatan made use of its computer-aided design software to optimise sheet cutting and placement, reducing the original anticipated wastage from 15% to 7%. To conform to the clientâ€™s requirement for a bright-coloured lining system, Aquatan formulated a light-blue Hyperliner master batch. This material was tested for acceptability in potable water installations. In passing this test, it was found to be inert to such a degree that it was also suitable for arduous applications that include the lining of demineralised water tanks in the power generation sector.
Sub-liner drainage system To provide for the management of any water that could leak through the lining, or originate from groundwater, the Hyperliner was paired with a sub-liner drainage system consisting of a polyethylene flownet and a woven highmodulus geotextile. The latter was placed under the liner and over the flownet. This prevented the high hydraulic pressure on the lining system from deflecting the geomembrane into the voids of the flownet, thus reducing the drainage flow path volume. The drainage system is maintained at atmospheric pressure and water flow is monitored via a detection pipe that connects the sub-liner drainage system to atmosphere. The pipe exits through the tunnel below the reservoir. This design was specified by SS&O after system pressure tests had been conducted on an apparatus built by Aquatan. This innovative approach was needed since a suitable test rig capable of simulating the huge pressure on the lining system was not commercially available.
Inlet energy dissipater During operation, two inlets enter the structure near the top of the reservoir and the incoming water runs down the lined slope about 42 m to the floor. In order to protect the lining from abrasion and turbulence damage, the Hyperliner thickness was increased to 6 mm in a 2 m wide section all the way down the slope An internal under the inlets. view showing the overhead Further protection precast roof and was provided by a the Hyperliner 6 mm thick lining layer installation extending into a splash pool located about 6.5 m out on to the floor. As the Hyperliner is not adhered to the underlying concrete surfaces, it has to be mechanically attached to the substrate to avoid being shifted by water turbulence. This was achieved by means of a specially produced profiled polypropylene batten section, 45 mm wide and 8 mm thick. These batten sections were strategically located and fastened by Upat UN 6/55 wall plugs recessed and installed through the batten and lining at 300 mm centres. To ensure the nail protrusions through the Hyperliner did not act as leak points, the nail heads were recessed and the batten strips were capped by a layer of Hyperliner 1 500, which was welded to the main liner, rendering the fastening system completely watertight. Back in 1991, the original geomembrane lining contract, including remedial concrete
Aquatanâ€™s Hyperliner was used to line the two machine shafts at the Palmiet Hydroelectric Scheme
work, took over two months to complete, at a contract value of approximately R2.3 million. Thatâ€™s a significant return on investment in close to three decades of operation and the same EVA technology is still applied today by Aquatan on its reservoir projects. Umgeni Water is now embarking on the rehabilitation of the concrete roof structure, after which the internal works will commence. The 27-year-old Hyperliner will of course be monitored regularly. Given the current observed state of the Hyperliner, it is anticipated to perform for another 5 to 10 years. To ensure the integrity of the liner system for years to come, Aquatan will, as part of the repair process, apply its electric leak-location system to detect discontinuities in the Hyperliner resulting from the roof repairs.
A Hyperliner installation at Parktown Reservoir
IMIESA May 2018
Pumps & Valves
Casting the perfect mould
Established in 1952, APE Pumps has retained its leadership position thanks to its 66 years of innovation in pump engineering. A prime example is its ongoing investment in the art of pattern making. By Alastair Currie
hen pumps are cast at the foundry, the precise tolerances that need to be achieved can be as exact as 1/1 000 mm, but before this process, work first begins in the pattern shop. This is where the casting models are handmade to technical specifications. In most instances, they are crafted in wood in a time-honoured tradition carried down over the centuries. Metal castings are still common, but more suited to mass production applications, whereas the wooden versions are intended for lower product volumes and unique, custombuilt requirements. Within South Africa, APE Pumps (APE) and its sister company, Mather+Platt, are among the few OEMs specialising in pattern making, which is becoming an increasingly scarce skill outside the foundry industry. “The advancement of 3D technology has its advantages when it comes to design and performance simulation,” explains Hennie Griessel, pattern workshop manager, APE. “We are also experimenting with the latest 3D printing technology, using plastic composite materials. This is an excellent way of enabling our engineers to walk through the final
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Pumps & Valves
prototype with our customers. But this always translates into the building of the pattern that will form the end result. Perhaps, in the future, 3D printing could replace wood once the technology becomes more advanced and the costs come down, but certainly not in the foreseeable future.” Currently, Griessel has three apprentices studying under him. Once they’ve passed their trade test, they will join an elite group of highly skilled artisans in South Africa.
Modifications and retrofits APE has the expertise to make a pattern for any application, and frequently devises replacement solutions for customers with older pump models where the original technical drawings have been
lost or the OEM is no longer in business. At other the casting comes back from the foundry, times, patterns are made where clients request the pumps are then machined and finished alterations to existing APE or Mather+Platt OEM according to their specific model type. All pumps designs to achieve the right flows and pressures are rigorously tested in terms of the company’s for their individual application. stringent quality-control process to ensure “That really puts our skills to the test,” that the highest standards are adhered to points our Richard Harper, marketing business and maintained. development manager at APE. “It’s an intricate “We form part of WPIL Limited, a process, with no margin for error.” The work multinational that owns leading OEM brands involved applies to any with manufacturing centres What really sets sized pump, extending based in Asia, Africa, Europe locally up to units us apart in South and Australia,” says Harper. that can weigh around “That means we have Africa is our pattern 4 tonnes. access to the best off-the“These patterns are making capabilities and shelf pump solutions for all so well made that they many of our orders are industry sectors. These are last for up to 20 years of backed by a suite of turnkey for custom builds.” productive use. A recent solutions with the in-house example is a 10x12 split-casing pattern for a capability to supply all the electro-mechanical major petrochemical client that took up to six systems needed. Through the Group, we also months to complete,” he adds. provide turnkey services for Southern Africa, including build, operate and maintain projects. Standardisation “But what really sets us apart in South Africa Traditionally, three individual patterns were is our pattern making capabilities and many of designed for stainless steel, bronze and cast our orders are for custom builds. Our team works iron. Now, APE has introduced one pattern with consulting engineers and clients to create format for all metallurgical compositions. Once the perfect fit,” Harper concludes. IMIESA May 2018
Pumps & Valves
Efficient solutions for Cape Town Vovani Water Products has been involved in the supply of pumps and energy-recovery devices to Cape Town’s emergency desalination plants. Henk Smit, managing director, Vovani Water Products, talks to IMIESA about the company’s equipment solutions. Tell us about your work at Cape Town’s desalination projects. HS Vovani Water Products is the sole distributor for Fedco equipment in South Africa, whose high-pressure reverse osmosis (RO) pumps and hydraulic pressure boosters (HPB) have been installed at all three of Cape Town’s current emergency desalination plants. The pumping equipment is installed in containers, with each pump and booster combination dedicated to an individual RO train. Vovani and Fedco supplied new equipment for the Strandfontein and Monwabisi desalination plants, which was manufactured at Fedco’s facility in Monroe, Michigan, in the USA. At the V&A Waterfront desalination plant, ready-build systems have been installed, which contain Fedco pumps and boosters. Vovani will be assisting its customers during the operation of these pumps and boosters.
What makes these pumps and boosters ideal for use in desalination plants? The Fedco pumps are very robust, and easy to maintain. The pumps used for desalination are manufactured from either duplex or super-duplex stainless steel, which is required
IMIESA May 2018
when working with seawater applications due to the high electrochemical corrosion of the equipment. The boosters, used as energyrecovery devices with the pumps, are also manufactured from duplex or super-duplex stainless steel, and are easy to install and operate. Using only one booster model for your specified flow rate, you can use the brine energy to create additional pressure required to the RO membranes for optimum permeate production.
High energy consumption is one of the biggest stumbling blocks associated with the rollout of desalination in South Africa. How does the Fedco equipment address this challenge?
Henk Smit, managing director, Vovani Water Products
Operating with the HPB units from Fedco, we are able to provide customers with a solution that will produce the desired flow rate and pressure at a reduced energy requirement. By using the Hydraulic Pressure Booster (HPB) you are reducing the pressure needed from the HPP which reduces the power consumption. Having the HPB installed the power consumed by the HPP can be cut in half which makes Desalination a more economical solution.This also helps with longterm operational costs, as the energy consumption to run the pumps is reduced.
Water Bearing™, which eliminates all pump bearing maintenance and numerous failure modes associated with oil/grease lubricated bearing systems. The Water Bearing absorbs the high levels of thrust generated by centrifugal pump operation, by using a balance disc integrated into the discharge of the pump housing. The pumpage (e.g. feedwater) provides all lubrication and cooling. Moreover, by locating the Water Bearing in the pump discharge, thrust loads act to place the pump shaft in tension. The Water Bearing is standard on the MSS, MSB, MSD, SSD and LP product lines.
What other advantages does the Fedco equipment offer?
What other opportunities exist for the application of Fedco equipment in Africa?
Fedco pumps use a patented
Fedco also manufactures pump solutions for brackish water applications, as well as other RO water applications where the feed pressure required can vary from 8 bar to 83 bar. Brine energy recovery for brackish water systems is available, as well as low-pressure drive conversion of brine hydraulic energy into electricity.
Brick health wins
total of 924 entries from 68 countries were submitted for the Berlin World Architecture Festival. Three South African projects were shortlisted, and one made the cut, winning first prize in the Health Completed Buildings category. Designed for the Gauteng Department of Health by Ntsika Architects, the winning entry was Westbury Clinic, a R23 million facility commissioned in 2016 that serves more than 55 000 people. This is a distinctive Corobrik Montana face brick structure, employing an English bond pattern reminiscent of the historic buildings found in Johannesburg’s CBD and neighbouring Newtown. A key feature of the build’s design is the way it reduces the transmission of airborne disease through various innovative systems, including
overall layout, patient and staff flow, and natural cross-ventilation. According to US Green Building reports, indoor air quality can be 10 times worse than outdoor air on smoggy days in big cities. Musa Shangase, commercial director, Corobrik, says the use of clay brick mitigates this, being a totally natural product that does not release toxic substances and resists mould, which is known to be one of the chief irritants for patients with lung diseases or allergies. Face brick, in particular, is the ultimate healthy building material, as it does not need interior finishing and does not give off the volatile organic compounds that are usually associated with paints and varnishes. Clay brick also promotes temperature and humidity control due to its thermal characteristics, reducing the need for air conditioning and heating.
The Westbury Clinic won first prize in the Health Completed Buildings category at the Berlin World Architecture Festival in November 2017 (Photo: Ntsika Architects, Michael Schmucker and Ryan Leukis)
Nadia Tromp, owner, Ntsika Architects, says the Westbury Clinic demonstrates that social, economic and environmental value can be generated for local communities through a holistic approach to development. “Local people were trained in the specific brick pattern employed and brickwork was done almost in its entirety by the local community,” she adds. Ntsika Architects has designed 13 clinics since 2011. Three are currently under construction: two in Alexandra, and the other on the Louis Botha Corridor of Freedom route.
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IMIESA May 2018
Geogrid improves safety
onstruction of the N2 Wild Coast Toll Highway between the Gonubie Interchange, north of East London, and the Isipingo Interchange in KwaZulu-Natal includes upgrading the R61 route to improved riding and safety standards. To accommodate the new design speed of 90 km/h (previously 60 km/h), major cuts and fills were required to improve the horizontal cur ve alignments on the steep, winding terrain. With the aid of finite element software, Kaytech provided a design proposal confirming the improvement factor that the addition of RockGrid PC would achieve. Consultancy group Mott MacDonald approved the proposal. RockGrid PC is a bi-directional, composite geotextile offering high modulus characteristics for reinforcement applications with the additional benefits of in-plane drainage capacity, separation and high installation survivability, and is the first such geotextile manufactured in South Africa.
Triamic Construction installed 211 500 m2 of RockGrid PC 100/100 (bi-axial tensile strength: 100 kN/m) from subgrade level up through the select fill layers at 1.5 m lifts. RockGrid PC was overlapped 150 mm every 5 m roll width with a 20 mm thick frictional soil placed between the geocomposite. Each 1.5 m lift was benched into the in situ material and, to intercept any migration of seepage through the fill, Kaytech’s Flo-Drain systems were installed against the benched face. Manufactured from high-quality HDPE, Flo-Drain consists of a 1 m vertical Flownet geonet wrapped in bidim A2 geotextile with a Flopipe 110 slotted collector pipe along the invert. In-plane drainage capacity of RockGrid PC ensures interception of migrating seepage, redirecting it to Flo-Drain collectors. With Kaytech’s geocomposite geogrid reinforcement improvement installed, the South African National Road Agency Limited is assured that section 8 of the R61, Majola Tea (KM 51) to Tombo (KM 66), meets the highest possible factors of safety required.
Inclusion of Kaytech’s unique RockGrid PC geotextile into the design of high-fill embankments raised safety factors to acceptable levels and provided, by far, the most effective and economical solution
IMIESA May 2018
A multifaceted approach to complex geology ensures a firm footing for a new commercial building going up in the City of Tshwane. The final structure will rest on a reinforced concrete raft foundation.
olomitic formations pose unique construction challenges, requiring efficient and cost-effective solutions. A case in point is the Lakeside Offices project – a Growthpoint Properties development in Pretoria where severe site conditions were successfully addressed through integrated infrastructure deliver y company Aecom. As a starting point, Kim Timm, executive: Structures, Aecom, emphasises the importance of not focusing on the structural and geotechnical system elements in isolation, since they need to work together effectively. “Upfront design and planning mitigate the risk considerably, allowing for a robust solution to be found. This permits the developer to focus on the budget, even when dealing with the unThe entire footprint of the site expected and unknown,” was dynamically compacted. she explains. A 14.5 t pounder was dropped Aecom’s final design saw the site excavatabout 4 600 times on-site, ed to the anticipated followed by the smoothing or founding level, ranging ironing phase from 7 m to 1 m below natural ground level. At 5 m below the founding level, the bedrock was blasted, excavated and blended with an on-site chert residuum mix, and recompacted. Simultaneously, high-lying weathered altered dolomite (WAD) was removed and replaced. The entire footprint of the site was then dynamically compacted. A 14.5 t pounder was dropped about 4 600 times onsite, followed by the smoothing or ironing phase. This created an even soil mattress above the highly variable rock profile, and below the structural foundation. It also assisted in pre-collapsing any high-lying potential cavities and weak spots. About 17 700 m3 of material was removed from site during this process. A
IMIESA May 2018
further 23 000 m3 was excavated, blended, and recompacted back into place.
Raft design The structural foundation system is a 2.25 m reinforced concrete raft, designed to span a 15 m sinkhole. The raft was designed on a mattress of variable spring stiffness, adjusted for the depth to bedrock, and the anticipated depth of the WAD and enhanced soil mattress zone. This was updated based on blast and compaction logs, as well as on-site tests during earthworks. The raft depth was optimised by balancing moments and deflections under standard ser viceability and ultimate limits, as well as accidental sinkhole conditions, to determine the most cost-efficient and appropriate thickness. The raft footprint was approximately 82 m by 68 m, necessitating 13 200 m3 of concrete and 1 500 t of reinforcing steel. The raft construction was divided into nine main continuous concrete pours of about 1 400 m3 each, with a smaller 10th pour thereafter.
Thermal and shrinkage design Large-scale concrete pours of this nature require careful thermal and shrinkage design and integrated logistical planning to ensure uniform concrete supply at the appropriate temperature. Three readymix batch plants were used, with up to 18 trucks on continuous rotation, supplying up to three pumps during the pour. Evaporation rates were calculated ever y 45 minutes during pouring, with misting nozzles laid out to reduce the evaporation rate when this became problematic. Mix designs and the sequence of each pour ensured a slow temperature build-up, with a peak of 62°C in the centre of the concrete, and no more than a 25°C differential temperature from the thermal centre of the concrete to the sur face.
This was monitored during the curing pro- depths were founded according to profiles cess by three sets of five thermal probes based on the anticipated locations of the placed at different levels and locations movement and mobilisation. In the short within the raft. The sur face tempera- term, this provided a high-precision spot ture was maintained by thick polystyrene settlement value. In the long term, it was sheets and insulating thick wooden shutter linked to the BMS system, and ser ved as boards to prevent excessive sur face cool- an early warning signal for developing sinking during the night. holes at depth. In order to achieve additional Countering water peace of mind, a system ingress was created to monitor 3 Dolomitic sinkholes and track the resultusually result from ant ground, raft and var ying water levels structure movement. The raft footprint was at depth. Part of the This was achieved by approximately 82 m by 68 m, design principles logging location tags necessitating 13 200 m3 of of the project as a on the rafts at each concrete and 1 500 t of whole was to isolate column location, surreinforcing steel the ground from water inveyed biweekly. gress as best as possible, In addition, three-rod exwith all ser vices running in HDPE tensometers were installed at three locations on the raft. Each exten- pipes within a secondar y sleeve, linked to someter location was close to a previous- the BMS system for early leak detection. ly identified high-risk area. The three rod Ongoing dolomite management is an es-
13 200 m
“The structural foundation system is a 2.25 m reinforced concrete raft, designed to span a 15 m sinkhole.” sential part of the lifespan of the structure as a whole, with appropriate water management systems as a core principle. The earthworks contract has been completed by Stefanutti Stocks Geotechnical, while the raft and first suspended floors have already been cast by main contractor WBHO. “Structural completion is due for end July 2018, with project completion early 2019,” Timm concludes.
Roads & Bridges
Founded in KwaZulu-Natal in 1988, National Asphalt is now a leading supplier in South Africa, with extensive local and crossborder project experience. By Alastair Currie
Founded in KwaZulu-Natal in 1988, National Asphalt is now a leading supplier in South Africa, with extensive local and cross-border project experience. By Alastair Currie
ithin the Tshwane region, National Asphalt has been part of the city’s infrastructure landscape for three decades, servicing the market from its Bon Accord facility, which has two plants with a combined capability of over 200 tph. Historically, projects range from urban streets to provincial networks, as well as specific highway sections passing through Tshwane that fall under Sanral, in addition to work for the N4 Bakwena Platinum Corridor Concessionaire. New contracts awarded in 2018 include the supply of some 58 000 t of asphalt from the Bon Accord plant for a resurfacing project on the N4 from Section 10 km 18.49 to Section 13 km 3.23, which is being carried out by Roadmac Surfacing. Also recently awarded is an order for the supply of approximately 35 000 t for another N4 project, which will be supported from National Asphalt’s Rustenburg facility. The scope here entails the construction of a second
IMIESA May 2018
carriageway between the Ga-Rankuwa Interchange (M17) N4-9 km 24.32 to Brits Interchange (R512) N4-10 km 19.3, with the works being undertaken by Raubex Construction. Meanwhile, past orders for Tshwane include the supply of around 50 000 t of asphalt for various works between December 2014 and June 2017.
A history of innovation National Asphalt’s investment in ongoing research and development has enabled the company to trial and validate a number of proprietary products and allied construction methodologies from around the world that have since become the mainstay in South Africa. Examples include reclaimed asphalt (RA), where National Asphalt was one of the early adopters locally, cold mix asphalt, warm mix asphalt, and EME (a French acronym for high modulus asphalt). The formulation of advanced modified binders is a further development that significantly extends pavement life. National Asphalt subsidiary Shisalanga Construction is also leading
Roads & Bridges
the way with hydrocutting technology, outside of Durban between Candella deployed for surface texturing, Road and the Westville rubber and spillage Pavilion. “Used in base removal. Another layers, EME’s stiffness Shisalanga innovation properties have been New contracts awarded is the introduction proven to outperform of unique thin layer standard mixes in in 2018 include the supply asphalt (Steel Flow), this application,” he of some 35 000 t which incorporates points out. of asphalt for a a high percentage Warm mix asphalt is resurfacing project of recycled steel slag another product with on the N4 and is an affordable great potential, since alternative to conventional it’s produced at a lower double seal. temperature with fewer emissions “We actively engage with our clients, – just one of the benefits compared to whether private or public, to develop hot mix. Warm mixes also extend the time creative solutions by researching the best window, allowing the mix to be transported products and techniques available,” explains over longer distances and paved at Sean Pretorius, managing director of lower temperatures. National Asphalt. Sustainability To date, National Asphalt has achieved a From an overall sustainability perspective, number of breakthroughs. Examples include Pretorius believes that RA is one of the better the use of EME for eThekwini’s GoDurban options currently available, especially since bus rapid transport system, together a number of metros, including Tshwane, have with the upgrading of a section of the N1
35 000 t
access to large stockpiles of material. It’s also becoming a mandatory requirement stipulated by Sanral. “Another benefit of RA is that it assists in reducing the impact of the bitumen supply gaps that are unfortunately becoming more common in the South African market. The use of 100% RA mixes will become a future reality,” he adds. As part of the Raubex Limited Group, National Asphalt is a responsible corporate citizen and committed to meeting government’s transformation goals, which fall under the ambit of sustainability. “In this respect, we’re in discussions with Qualifying Small Enterprises (QSEs) with the possibility of subcontracting the asphalt paving component of our supply contracts. We also assist where we can in terms of skills development via our socio-economic initiatives. Through the Cadiz Programme, for example, we’ve successfully sponsored a number of young learners throughout the country. Our hope is that some of them will find a career in roads construction, ” Pretorius concludes.
Roads & Bridges
Controlling silica dust exposure Sabita has recently issued an HSE communication notice regarding the control of silica dust exposure on asphalt pavement milling machines, which is under discussion and will be forwarded to industry once finalised. By Anton Ferreira*
ny thousands of South African workers are exposed to respirable crystalline silica (RCS) that exceeds current occupational exposure limits. Inhaling RCS can cause silicosis, a debilitating and potentially fatal lung disease, as well as obstructive pulmonary and renal disease. Milling and cutting can create airborne dust containing silica. However, ventilation controls used in conjunction with water-spray systems can consistently reduce exposures below the OEL-CL (occupational exposure limit – control limit). Employers have legal duties and obligations in accordance with the Occupational Health and Safety Act (No. 85 of 1993, as amended). Section 8 states: “Every employer shall provide and maintain, as far as is reasonably practicable, a working environment that is safe and without risk to the health of their employees.” In par ticular, reference is made to the Hazardous Chemicals
IMIESA May 2018
Substance Regulations – and to ensure that arrangements are in place to guarantee full compliance. The minimum expectation regarding the assessment of potential exposure is to determine if, and to what extent, operators and other workers involved in asphalt milling are exposed. This baseline assessment should then be used to make decisions on what further action is required to comply fully with the regulations.
Safer milling Typical ventilation controls designed to reduce silica exposure on asphalt pavement milling machines include a collection hood, a fan and ductwork, which should all be in good working order. Milling machines should also be designed to allow the operator to temporarily turn the ventilation control off when milling into the wind. Plus waterspray controls should always remain on, regardless of wind direction. When ventilation controls are unavailable, water-spray systems that
During routine asphalt milling operations, ventilation controls used in conjunction with water-spray systems can consistently reduce exposures below the occupational exposure limit – control limit
are properly designed, operated and maintained can provide a significant reduction in the milling machine’s dust generation. The machine operator’s manual should contain a maintenance schedule for the water-spray or ventilation controls. This manual should include detailed sketches, performance criteria and troubleshooting instructions for equipment owners to use in their periodic inspection of the controls. For more information on the design of controls, and the methods used to test them, refer to the US National Institute for Occupational Safety and Health document ‘Best Practice Engineering Control Guidelines to Control Worker Exposure to Respirable Crystalline Silica during Asphalt Pavement Milling’ (www.cdc.gov/niosh/ docs/2015-105). *Anton Ferreira is an HSE specialist at Sabita.
Building an asset class After years of delays, Eskom has signed contracts worth R55.92 billion with 27 new independent power producers (IPPs) under the Renewable Energy Independent Power Producer Procurement (REIPPP) programme. By Danielle Petterson
Prudence Lebina, CEO, GAIA Infrastructure Capital
his bodes well for the industr y as it provides the policy certainty that investors require, says Prudence Lebina, CEO, GAIA Infrastructure Capital. She believes the REIPPP has been ver y good for the countr y, having made a tangible difference at local levels. While there has been pushback by some against the REIPPP, Lebina, being from the mining sector, sees a clear space for coal and renewable energy to coexist. “We need to appreciate that these power stations and mines have a finite life, and while there is currently no growth in South Africa, we need to prepare for the future – we don’t want to find ourselves caught
off guard and without enough power again.” REIPPP also highlights the fact that there is clear opportunity for the private sector to work with government to effectively source capital for infrastructure development, says Lebina. Private sector participation is not only a source of capital but it also brings with it efficiencies and good management, which are clearly needed in the infrastructure space considering the extensive delays with megaprojects like the Medupi and Kusile power stations.
An infrastructure asset class While government’s recommitment to REIPPP speaks to the growth of the programme, it also speaks to the growth of GAIA and its industr y assets, explains Lebina. GAIA is an infrastructure investment agency focusing on emerging South African infrastructure investment opportunities, specifically in the energy, transport and water and sanitation sectors. GAIA listed on the JSE in 2015 as a special-purpose acquisition company
(SPAC) and raised R550 million on listing. Thirteen months later, the company acquired its first viable asset, an effective see-through economic interest of 25.2% in the Dorper Wind Farm. The 98 MW plant located in the Eastern Cape had been in operation since 2014 and has a 20-year PPA with Eskom. In September 2017, the company acquired its second asset, an effective see-through economic interest of 20% in the 74 MW Noblesfontein Wind Farm located in the Northern Cape. “Our intent is to be a diversified infrastructure investment company,” says Lebina. “Ordinarily, shareholders wouldn’t have the opportunity to get exposure to these kinds of large-scale infrastructure assets. We can provide shareholders with the opportunity to access these and the long-term cash flows they provide.” Lebina believes that while infrastructure brings diversification to portfolios, South
IMIESA May 2018
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Africa is lagging behind in embracing infrastructure as an asset class. She says it is not well understood in South Africa, nor are the risks and returns dynamics of the assets. Pension funds and asset management firms often have limited investment expertise in the infrastructure asset class and GAIA presents the investment community with an opportunity to match their long-term capital with long term cash income flows.
Strong investment pipeline “Our intent is to pursue our investment pipeline on the back of raising capital,” says Lebina. Now an investment holding company, GAIA has a defined investment policy approved by shareholders. The development of GAIA Infrastructure Capital’s investment pipeline is outsourced to GAIA Infrastructure Partners. The pipeline currently consists of R3 billion in projects, R1.5 billion of which is bankable, including energy, road and water projects. The company is now working to raise the capital to invest in these projects. GAIA only invests in operational or near-operation assets, being projects that are not more than six months from commercial operation and income generating. These present low investment risk and stable, long-term cash flows, offering investors predictable returns. The two wind farm projects in which GAIA has invested are a good indication of this. They are highly profitable and after only one year of operation, GAIA was able to declare its maiden dividend of 63.5 cents in 2017.
The board will also only invest in projects with a social, environmental and governance policy appreciation. The REIPPP projects are well suited for this as the policy provides clearly defined scope for BBBEE participation, community involvement and job creation, says Lebina.
Recipe for success What has made REIPPP so successful is the long-term power purchase agreements (PPAs) signed by Eksom and guaranteed by National Treasury, should the power utility default on its agreement, explains Lebina. She believes there are definite opportunities for the programme to be replicated elsewhere, both within South Africa as well as Africa as a whole. Outside of South Africa, corporates have adopted a similar model in which they commission renewable energy plants with PPAs in place to power their own operations. Locally, Lebina says government should look at the successes of REIPPP and replicate it in other sectors, such as the water and sanitation space, where there is minimal private sector involvement. “We need engagement between the state and the private sector and we need government to stick to its policies and plans. We cannot afford for government to change policy, because investors want to invest their money where there is policy certainty,” says Lebina. “Unlocking private equity is critical not only for GAIA but for the country as a whole because it speaks to what South Africa needs – job creation, skills transfer, social upliftment and transformation.”
“We need engagement between the state and the private sector and we need government to stick to its policies and plans.
IMIESA May 2018
Transport, Logistics, Vehicles & Equipment
LB Equipment is gearing up its Sumitomo excavator offering to meet an anticipated surge in demand. “We’ve brought in extra units, especially 21-tonners, as they are the most commonly used excavators in South Africa. We have also tagged them at competitive prices along with extras and extended-hour warranties,” says Rhett O’Neill at ELB Equipment. Sumitomo is a specialist excavator manufacturer with more than 100 years of experience in earthmoving and has won numerous accolades in its home country. These include Japan’s prestigious Good Design Award and Grand Award for Energy Conservation. Fast, powerful and durable, Sumitomo machines have a well-earned reputation for operating efficiency and simplified maintenance. Sumitomo excavators also have one of the lowest diesel consumption rates in the industry. Speed Priority, Heavy or Auto engine modes enable the operator to select the best power output for the job at hand.
Local team ELB Equipment has represented Sumitomo in South Africa for almost 30 years, backed by an extensive Southern African dealer network. To help lower customer fleet overheads, ELB Equipment has sourced more costeffective undercarriage and service parts through Sumitomo, which makes owning and servicing more affordable than ever before.
A large shipment of Sumitomo excavators has arrived in South Africa in anticipation of future growth of the economy
Transport, Logistics, Vehicles & Equipment
Compact by design
81 700 kg This machine has an approximate operating weight range of 80 500 kg to 81 700 kg. Bell Equipment and Kobelco celebrated their new partnership at bauma Conexpo Africa 2018 by performing the customary Japanese kagami-biraki, or barrel-breaking ceremony. From left to right are: Stephen Jones (marketing director, Bell Group), John Boyd (managing director: Construction Machinery Middle East and Africa, Kobelco), Takehiko Nakai (executive officer: Excavator Sales & Marketing Division, Kobelco), Gary Bell (chairman, Bell Group) and Leon Goosen (chief executive, Bell Group)
ell Equipment has broadened its partnership with Japanese excavator specialist Kobelco Construction Machinery following the unveiling of three compact mini excavators at bauma Conexpo Africa 2018. These comprise the 5.5 t SK55SRX, 7.5 t SK75SR and 13.5 t SK135SR models, which feature a short rear swing that reduces the turning radius for superior manoeuvrability in limited spaces. “With Kobelco leading the industry in terms of short rear swing excavator innovation, we’re confident that these machines will gain strong market acceptance locally, particularly since the 5.5 t and
7.5 t segment is growing in Southern Africa,” explains Stephen McNeill, product marketing manager, Bell Equipment. In addition to displaying the smallest excavators in its range, the bauma show also provided an opportunity for Bell to exhibit its largest Kobelco excavator, the SK850LC, for the first time in South Africa. This machine has an approximate operating weight range of 80 500 kg to 81 700 kg. “Our standard Kobelco models have been extremely well received across all industries and we expect our mini excavators to expand on this achievement,” concludes McNeill.
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Transport, Logistics, Vehicles & Equipment
A solution for every task
The classic areas of application in asphalt construction and earthwork are covered with Hammâ€™s programme for specialised machines. Consisting of 88 tandem and combi rollers, 18 pneumatic tyre rollers and 63 compactors, clearly subdivided in the weight classes customary in the market, Hamm offers an exhaustive range of modern, future-proof machines for roadbuilding and earthworks.
The Hamm product portfolio currently comprises 63 compactors with operating weights between 5 t and 25 t
Compactors for earthwork
GRW: pneumatic tyre rollers for every market
The GRW 180 280 from Hamm is the most advanced pneumatic tyre roller in the world
In the tandem roller segment, Hamm carries machines with operating weights from 1.5 t to 15 t, and drum widths from 0.80 m to 2.14 m. All 88 tandem and combi rollers are finely graduated according to operating weight. They stand out for their ease of operation, high productivity, extensive equipment configurations and useful options. Rollers include: - HD CompactLine: articulated compact rollers from 1.5 t to 4.5 t - HD+ series: all-rounders for high-quality compaction - DV+ series: pivot-steered tandem rollers for ultimate precision.
Hamm has a total of 63 compactors for earthwork, ranging from 5 t to 25 t, with working widths from 1.37 m to 2.22 m. All compactors have three-point articulation for even weight distribution and enormous driving stability. They also stand out for their ease of operation, excellent visibility, extremely high levels of safety, exceptional productivity, and a wealth of equipment variants and useful options. Compactors include: - H CompactLine series: impressively compact - H series: for the big earthwork jobs - VC compactors: rock crushing and compacting.
Hamm also stands out from the crowd in the pneumatic tyre roller segment, as it has done since the 1960s, when it was the first ever manufacturer to launch a pneumatic tyre roller. Today, with 18 different models, Hamm ranks among the manufacturers with the largest ranges of pneumatic tyre rollers in the world. Pneumatic rollers include: - GRW 180 / 280: asymmetric frame provides outstanding overview. With 88 tandem and combi rollers, Hamm is the manufacturer with the largest product range in this segment in the world
IMIESA May 2018
Cement & Concrete
New breakthrough for precast
The argument for precast wins at the North East Parkade, showcasing many of the technological advances in this construction field that are enabling designers to develop complex structures at a faster rate than conventional cast in situ techniques.
outh Africa’s first precast concrete parkade was recognised for its innovative design and construction at the Concrete Manufacturers Association’s (CMA’s) recent 2018 Awards for Excellence. The project won the NPC Building Elements Award for Engineering Excellence. Comprising seven storeys and a total floor area of 65 000 m², the North East Parkade is also South Africa’s largest precast concrete framed structure to date, and was built as part of an expansion and revamp of Accelerate Property Fund’s Fourways Shopping Mall in Johannesburg. North East Parkade was initially conventionally designed using cast in situ technology. However, time constraints and a need to minimise disruption prompted the design team to investigate and propose an alternative method using precast columns, beams and slabs as the frame’s main structural elements. This was accepted by the client, with precast
manufacturer Echo Prestress commissioned to produce 78 000 m² of slab material, which was used for the flooring and retaining walls. Together with other precast elements, such as crash barriers/balustrades and stairs, these were combined with cast in situ concrete to create a hybrid construction system.
A propless approach Besides being faster and causing less disruption, the precast construction method adopted is propless. This allowed for early occupation of the lower floors while the upper levels were still under construction. According to Daniel Petrov, technical director, Echo, hidden column and beam connections were critical in complying with the architectural design criteria and these had the added advantage of simplifying the installation process. “Vertical load transfers up to 900 t/column were facilitated by purpose-designed connector An aerial view of North East Parkade
IMIESA May 2018
Integrating the precast elements
bolts and shoes, which enabled the columns to be bolted together. The columns were cast in two-storey lengths to minimise the number of joints. As soon as the columns were secured in position, rectangular beams were seated on steel billets, which had been cast into the columns. Thereafter, the placement of the slabs on to the beams could follow immediately,” says Petrov. The detailed structural design was carried out by Precast Concrete Consultants. Only 475 mm deep, the shallow beams were designed to suit the restricted 3 060 mm floor-to-floor height. A floor screed was applied as a structural component and enhanced the stiffness of the beams by more than 200%. During load testing under a live-load application, this resulted in deflections of not more than 2 mm on a 7 850 mm beam span. “The true value of this flagship project is yet to be fully realised,” Petrov continues. “However, it already represents a significant shift towards prefabricated construction methodology and is encouraging construction professionals to take a fresh look at the benefits of precast. “Moreover, continuous investment and innovation by the South African precast concrete industry will pave the way for ever more complex layouts and external treatments,” he concludes.
Cement & Concrete
New line for Walmer Currently in progress, an increase in the capacity of the existing Driftsands Collective Sewer Augmentation caters for ongoing residential and commercial expansion within Port Elizabeth’s Walmer suburb.
he scope of works entails the construction of a 1 400 mm diameter concrete HDPE-lined sewer measuring 1 850 m in length, forming part of Phase I of this four-phase project. Construction commenced in the second quarter of 2017. Rocla was selected to supply 780 lengths of Class 75D HDPElined pipes, plus manhole access pipes. The sewer starts from the Driftsands Wastewater Treatment Works and terminates at the Por t Elizabeth International Airport boundary. The existing gravity sewer was constructed in 1983 and could not be upgraded. Therefore, a realignment of the
4.2 km On completion, the 4.2 km fourphase project will have addressed the sewerage requirements for existing and future developments for the western suburbs of Nelson Mandela Bay Municipality
line route is being undertaken. The first 1 460 m runs parallel to the current 1 050 m Driftsands collector sewer and then branches off to bypass a planned runway extension at Por t Elizabeth International Airport. “We started manufacturing the HDPElined pipes in May 2017 at an average rate of eight pipes per day. We achieved this by double stripping our four available moulds and we delivered the first pipes to site in July 2017,” explains Graham Howell, sales consultant, Rocla. “We made minor improvements to the product after numerous on-site visits and we continued with production for the remainder of the year. Ten manhole access pipes were also ordered and these were cut in the Rocla yard to specification, which allowed the laying of pipes to continue uninterrupted, thus giving the contractor the oppor tunity to achieve good production on-site,” he continues. Rocla made further design changes during the manufacture of the manhole rings and offered rings and cover slabs with internal HDPE liners. Rocla believes this innovative development could become the accepted and required standard for all future outfall sewer projects. “The second phase is due to start during 2018, which will most certainly present Rocla with new and interesting challenges, as the conditions include rock and very deep trenches, but we are more than confident in our ability to overcome them,” Howell adds. On completion, the 4.2 km four-phase project will have addressed the sewerage requirements for existing and future developments for the western suburbs of Nelson Mandela Bay Municipality.
IMIESA May 2018
Cement & Concrete
Tips for extended durability Although concrete is an extremely robust and forgiving construction material, some durability issues do crop up and are sometimes overlooked. John Roxburgh outlines some of the less common durability issues that may be encountered.
teel corrosion is the most prevalent durability problem associated with concrete. For this reason, great care is usually taken to ensure the correct placement and cover of steel reinforcement. However, what is sometimes overlooked is the environment into which the concrete is placed, a factor that could substantially affect planned durabilityÂ targets. Generally, durability issues can be categorised under mechanical (and physical) or chemical deterioration. Chemical deterioration is further subdivided into the chemical dissolution or conversion of the hydration products.
Corrosion of steel reinforcement is a major cause of concrete deterioration, particularly in harsh coastal environments
IMIESA May 2018
Mechanical (and physical) deterioration mechanisms Erosion and abrasion: Erosion is caused by fluids, most often water, containing abrasive particles wearing down the surface of the concrete. Abrasion is caused by wheeled traffic on floors and pavements as well as
Salt crystallisation resulted in surface exfoliation on these concrete pavers
abrasive material, as in ore passes and silos. Strong concrete with little surface laitance, well cured and finished off along with abrasion-resistant large aggregate, will slow down the rate at which the concrete surface wears. Specialist surface hardeners will also help. Cavitation: The collapse of very high-pressure vapour bubbles, created by fluid jumping off the surface of the concrete due to sudden changes in direction, can lead to massive damage within a short period of time. Aerating the fluid to prevent pressure build-up is an effective way of preventing cavitation, a technique often applied on dam spillways. Salt crystallisation: This is often called â€˜salt jackingâ€™ and tends to occur along the coast where the concrete is subject to high salt concentrations. Salt in solution is transported into the concrete. When the concrete dries
Cement & Concrete
out, it re-crystallises: the expanding salt crystals exfoliate the concrete surface. Freeze-thaw: Ingress of water that subsequently freezes can cause the formation of cracks due to the expansion of the ice. However, air entrainment can effectively prevent this. The size and, more importantly, the spacing of the air bubbles are key factors in how effective the air entrainment will be.
Chemical deterioration mechanism Dissolution of hydration products Acid attack: The calcium in the concrete hydrates has a high solubility in acids. Often, a sacrificial calcareous aggregate is used to get an even wear and slower disintegration of the concrete surface. With strong acids, a sacrificial layer or an acid-resistant coating is more effective in protecting the concrete. Soft or pure water attack: Waters with very low ion contents will cause the dissolution of the hydrates within concrete. Soft or pure waters are often found in waters that have not come into contact with calcareous rock.
Chemical conversion of hydration products There are Alkali silica reaction many well(ASR): Reactive silicas researched methods contained in the aggregate can react with of ensuring that active alkalis within the concrete performs concrete pore structure. for its service life This forms an expansive within any gel, which results in the concrete cracking. environment.â€? Avoiding aggregates John Roxburgh, lecturer, containing reactive silica, The Concrete Instituteâ€™s School of Concrete Technology minimising the active alkalis within the concrete, and preventing mixing water is kept low, and preventing the the ingress of water into the concrete are ingress of water into the hardened concrete, effective measures in preventing ASR. will also prevent sulfate attack. Sulfate attack: A combination of sulfates, Interestingly, all of the above described calcium hydroxide and tricalcium aluminates deterioration mechanisms can be mitigated in the concrete can lead to the formation or even prevented by designing the concrete of two expansive compounds: gypsum and mix with a lower water-to-cement ratio and ettringite. This can cause the concrete to implementing good site practice by ensuring soften and crack. Using sulfate-resisting excellent compaction and optimising cement or extending the cement with fly ash or curing. By doing this, the concrete will be slag can help prevent sulfate attack. Ensuring less permeable, which is key to a more that the sulfate content in the aggregate and durable concrete.
A strong foundation for infrastructure success
Cement & Concrete
Carving a competitive niche
Antony Offenberg, general manager, Mapei South Africa
onstruction chemical manufacturer Mapei South Africa recently unveiled its new state-of-the-art facility in Germiston, Gauteng, positioning the company for sustained growth. Since entering the market in 2011, Mapei has earned a sound reputation for technical expertise and is now one of the leading local suppliers of construction chemicals and adhesives in Southern Africa. Antony Offenberg, general manager, Mapei South Africa, says this success is largely due to its customer-centric approach and unique focus on quality. “We’ve carefully noted the requirements of the market, as well as individual customers, to develop solutions that meet their current and future needs,” he explains. Mapei’s advanced new manufacturing plant, supported by smart technical teams, as well as support infrastructure such as laboratories and training facilities, is the culmination of these requirements, serving the retail industry, contractors and professionals. Customers will have access to the company’s vast product lineup, which includes additives used in the manufacture of cement, concrete additives, adhesives, as well as a wide range of specialised construction and related chemicals. Both liquid and powder products are manufactured at the Germiston plant and are available in handy retail-oriented packages or in bulk capacity for large-scale contracts.
ROCLA is South Africa’s leading manufacturer of pre-cast concrete products. Surpassing 100 years of product excellence, including pipes, culverts, manholes, poles, retaining walls, roadside furniture, sanitation and other related products within infrastructure development and related industries.
All products are manufactured according to relevant international and SABS standards and endorse the highest possible compliance towards sustainable environmental practices. This is carried across through all training courses and seminars offered at Mapei’s on-site training facility, where global experts are regularly brought in to share their skills with contractors, installers, as well as building industry professionals for applications that include cement production, down-the-line concrete manufacture or cured product repairs and finishing. “We are a multifaceted solutions provider that competes with construction chemical suppliers across all phases of the construction timeline. And, our focus on technical service and training truly sets us apart,” Offenberg concludes.
Visit us on www.rocla.co.za for our nationwide branches 54
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Cement & Concrete
ituated close to Addo Elephant National Park in the Eastern Cape, the Langbos informal settlement is one of the poorest in the region, lacking basic amenities like running water and electricity. However, that situation is progressively improving, thanks to various outreach programmes. A prime example is the initiatives led by non-governmental organisation Intsikelelo, which recently raised donor support for the construction of the Langbos Children’s Shelter. This included a contribution from specialty chemicals company Sika. Rigo Govoni from Structural Solutions, along with architect Jason Erlank from JE Architects, approached local Sika area sales manager John Zehmke for assistance. After evaluating the project needs, a total of 125 ℓ of Sika’s Cemflex was donated and used as a protective and
waterproofing coating to the roofs and walls of the structure. Cemflex is a universal waterproofing and bonding agent. This acrylic-based emulsion improves the water resistance and adhesion of Portlandcement-based composites and was the perfect solution for the creative construction of the hut-like structures built as part of the new children’s home.
Sustainable elements The design of the shelter is based on the local style of the Langbos settlement and was constructed using SuperAdobe, a low-cost, environmentally friendly, earth-building technique. This
construction method also promotes community training and involvement in the building process, which was the case during the Langbos development. Other key sustainable features of the shelter include rainwater harvesting, grey- and wastewater recycling, and biogas and solar energy. With the innovative outlook of Chris Grava, president, Intsikelelo, the project came together, with the initial phase able to house 10 children along with a caretaker. These children are either orphaned or come from unstable homes within the Langbos rural community and so the new shelter will make a lasting difference during their formative years.
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Critical information on infrastructure development, maintenance and service delivery. The official magazine of the Institute of Municipal En...
Published on Jun 13, 2018
Critical information on infrastructure development, maintenance and service delivery. The official magazine of the Institute of Municipal En...