IMIESA May 2020

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IMESA The official magazine of the Institute of Municipal Engineering of Southern Africa

I N F R A S T R U C T U R E D E V E LO P M E N T • B U I L D I N G • M A I N T E N A N C E • S E RV I C E D E L I V E RY

Energy Insight What’s the best power platform?

City of Cape Town Invested in the future

Geomatics Mapping underground services

A foundation you can trust ISSN 0257 1978

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INSIDE

VOLUME 45 NO. 05 MAY 2020 www.infrastructurenews.co.za

IMESA The official magazine of the Institute of Municipal Engineering of Southern Africa

I N F R A S T R U C T U R E D E V E LO P M E N T • B U I L D I N G • M A I N T E N A N C E • S E RV I C E D E L I V E RY

Energy Insight What’s the best power platform?

City of Cape Town Invested in the future

Geomatics

WATER & WASTEWATER Custom mix for new reservoir

Regulars

A foundation you can trust ISSN 0257 1978

Infrastructure Funding

Editor’s comment President’s comment Index to advertisers

3 5 63

Pilecon Geotechnical Contractors provides solutions nationwide, backed by its technical team and piling fleet. Projects range from high-rise buildings to interchanges, with major new work in the pipeline. P6

Cover Story Foundations you can trust

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Thought Leadership Establishing an effective and participative construction sector 8

Roads & Bridges Bringing the community on board

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Environmental Engineering

The City of Cape Town is home to a vibrant mix of industries. Turn to page 19 for an in-depth feature on infrastructure delivery projects and programmes.

City of Cape Town Investing in the future

The art of gabion construction Geomembranes offer ideal dam solution

33 34

INS IDE 21 21 23 25 26

27 Making sludge sustainable 29 revolutionises filtration Virgin plate glass media Zandvliet’s mega expansion 30 showcases excellence 32 Pursuing carbon neutrality

19 ROADS & BRIDGES Bringing the community on board

Reigniting the Cape economy Inclusive housing at scale Growing South Africa’s digital economy Water and wastewater pumping excellence Treatment expertise perfected Making sludge sustainable Virgin plate glass media revolutionises filtration Zandvliet’s mega expansion showcases excellence Pursuing carbon neutrality

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Water & Wastewater Increased electronics usage poses risks Custom mix for new reservoir Get water wise Embrace advanced technologies

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Underground utility scanning and mapping

38 40 41 42

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Vehicles & Equipment 16 17

Human Settlements Giving land to the people

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The BIM revolution

Geomatics

Buildings Face brick adds vibrancy to Noordgesig Primary School Ecobricks on a commercial scale

IT & Software

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18

City of Cape Town

Reigniting the Cape economy Inclusive housing at scale digital economy Growing South Africa’s pumping excellence Water and wastewater Treatment expertise perfected

Desalination going mainstream – but are we ready?

Blended finance and bankable projects

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FOCUS ON

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20

Mapping underground services

20 21 23 25 26 27 29 30 32

BUILDINGS Ecobricks on a commercial scale

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Forming a route to Polihali

Energy The long wait is over – or is it?

Transitioning to a greener economy Implications for SA’s electricity supply industry Prospects of nuclear in SA’s energy mix

49 51 52 55

Covid-19 Considering the consequences of Covid-19

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Health & Safety The essential role of construction ergonomics

60

Cement & Concrete 62

Plaster’s crucial ingredient

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FOCUS ON SUSTAINABLE ENERGY FOR A

Brighter Future

INSIDE The long wait is over – or is it?

49

Transitioning to a greener economy

51

Implications for SA’s electricity supply industry

52

Prospects of nuclear in SA’s energy mix 55

IMIESA May 2020

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A

dversity tends to breed innovation.

For example, the technological advances spurred on by the First and Second World Wars were, at the time, arguably some of the most impactful in human history. In fact, pioneering work during the Second World War led to the birth of the first programmable computer in 1946. Information technology hasn’t looked back since.

Inadvertently, Covid-19 will go down in history as one of the next major change-makers. The global economic fallout will influence the structural and operational dynamics of every known government, enterprise and endeavour. Within the South African context, that adds a new dimension since the pandemic really brought home the inequality gaps in terms of infrastructure and access to technological services.

From a basic services viewpoint, a recent Department of Human Settlements, Water and Sanitation statement highlights the fact that some 14.1 million people still do not have access to safe sanitation, and around three million households to reliable drinking water. On top of this, the department states: “56% of wastewater and 44% of water treatment works are in a poor or critical condition, and 11% are dysfunctional.”

The spread of Covid-19 makes interventions in these areas critical, alongside the urgent need to respond to extended drought cycles.

Improved storage and reuse strategies need to be top of mind.

Connectivity issues As South Africa went into lockdown, it also became clear that connectivity is a vital requirement.

Statistics SA figures show that around 63.8% of South Africans had access to the internet in 2018. (In the UK, it was 90% for the same period.)

Smartphone ownership is also growing but comes at a cost that many still cannot afford.

For those scholars and university students without the means, this has made remote learning very challenging. Although the proactive provision of hardware and data by cellular providers, private and public education bodies has helped,

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a much broader-scale approach is required. Not just for now, but for all future education and training platforms.

Data prices have come down, but connectivity costs are still too high in global terms. Unless addressed, the cost of technology poses a major barrier to learning, SMME development and employment. The upside is that advances in highspeed, lower-cost fibre connectivity should change that picture for the better. Increasingly, more connected municipalities will be able to offer free capped or uncapped Wi-Fi as part of their smart city e-services solution.

Finding common ground In the mean time, government and industry need to find common ground on ways to stem unemployment and rebuild the economy. Policy certainly has never been more essential, together with the need to simplify and fasttrack procurement processes. Only then will government attract the private sector funds needed to bridge infrastructure gaps and invest in critical industries. These include agriculture, construction, ICT, manufacturing, mining, property, renewable energy, and tourism.

The Infrastructure Fund managed by the Development Bank of Southern Africa will be a crucial element in delivering bankable projects.

This is especially the case as a larger portion of public funds shift to support education, health, and social welfare.

Within the infrastructure space, Covid-19 has laid bare the hard truths we’ve known for years. It also presents major opportunities for new construction work, where technology will be the key to their planning, governance and realtime execution.

Alastair 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.

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PRESIDENT’S COMMENT

IMESA

Covid-19 pushes the pace of technology Thanks to a myriad of multimedia platforms, we’ve become accustomed to witnessing human tragedies unfold in far-flung parts of the globe. For most of us, these events have not been part of our daily reality.

Covid-19 has changed that perspective.

N

ow we’re all part of an encompassing threat, as well as the corresponding solution.

The upside is that we’re well equipped to respond proactively, thanks to these media platforms, which provide instant communication, plus rapid and collective decision-making in an increasingly remote world.

Alongside social media channels like YouTube, we’re experiencing an unprecedented rise in webinar and video communication that is changing the way we interact and work.

From an engineering, project and programme management perspective, we can expect the application of augmented reality (AR) and virtual reality (VR) technologies to accelerate.

Incidentally, AR and VR pass on major efficiencies in the design and execution of building and civils programmes. Virtual walkthroughs enable public and private construction sector stakeholders to verify work in progress within budget. Interconnecting via an enterprise resource planning system, secure, real-time information can also be shared and verified by strategic partners.

Poverty gaps Within South Africa, the pandemic has highlighted shortfalls in health and infrastructure delivery. It has also reinforced the fact that our

country has unacceptably high poverty levels, compounded by spiralling unemployment and education gaps. The need to reinvest in clinics, hospitals, housing, ICT, schools, sanitation and water is a top priority.

Poor hygiene and overcrowding were contributing factors in the demise of many during the Spanish flu (H1N1) outbreak in 1918.

Some 100 years later, it remains a key concern within our high-density informal settlements as we strive to combat this new virus. Like Covid19, N1H1 was novel. There wasn’t an existing vaccine at the time, or a built-up immunity.

However, the upside is that modern-day scientific and technological developments have responded far faster and more effectively in containing Covid-19. Scientists from all nations are now working around the clock to find a Covid19 vaccine.

spend. Included in the requests are immediate solutions to end procurement bottlenecks and corruption. Covid-19 demands a response.

As a major vehicle for positive change, the construction sector must be given priority. As we begin to reopen our economy, we need to ensure that we have highly functioning roads, airports and harbours in place, alongside the fundamentals of electricity, housing, water and sanitation.

Government continues to roll out its District Development Model. The goal is to ensure that each one of South Africa’s 257 municipalities is equipped to deliver on its mandate. Supporting this drive is a proposed R20 billion municipal stimulus package. The details have yet to be confirmed; however, effectively managed and monitored, this package will help improve the functionality of financially distressed municipalities. Technology will help us to perfect the process.

Revitalising construction For the beleaguered construction sector, the post-Covid-19 response is expected to be the catalyst needed to bring the industry back to life. According to Statistics SA, the sector’s contribution to GDP in Q4 2019 was approximately -0.2%.

For close on two years, leading stakeholders in construction have been lobbying government for a resolution to the hiatus in infrastructure

Randeer Kasserchun, president, IMESA

IMIESA May 2020

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Petrus van Straten disappearing down an auger hole to profile the subsoils SDA piling under way to support the installation of monopoles for City Power

Foundations you can trust Headed by directors Hugh Feely and Petrus van Straten, Pilecon Geotechnical Contractors provides solutions nationwide, backed by its technical team and piling fleet.

Projects range from high-rise buildings to interchanges, with major new work in the pipeline.

T

he formation of Pilecon is thanks to Feely and Van Straten’s entrepreneurial vision to offer a value-added geotechnical service to the South African market. A qualified geologist, Feely’s earlier consulting experience – gained working for companies like Drennan Maud, Golder Associates and Schwartz Tromp – subsequently led to his entry into the contracting space in 1992.

He managed the piling divisions of Jacked Pipelines/WK Construction, Saudi Arabia-based company Aject, and Geopractica Contracting.

Then in January 2018, Pilecon was formed.

Van Straten holds a BSc (Hons) Applied Sciences – Geotechnical Engineering and PR Tech Eng registration. Prior to forming consulting firm Geo Simplicity Geotechnical Engineering, Van Straten was with Dura Piling and then managing director of Stefanutti Stocks Geotechnical. He joined Pilecon as a director in March 2020. Pilecon and Geo Simplicity work together to provide a turnkey ‘geotechnical onestop shop’ for their clients.

A Level 4 BBBEE company, Pilecon employs dedicated rig operators and foremen with years of experience in the art of completing

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IMIESA May 2020

geotechnical installations in varied and difficult ground conditions.

Milestone & current projects “Every project is unique in terms of the underlying geology, groundwater and soil conditions, with the site footprint and future structure adding to the complexities of devising the optimum pile design,” Feely explains. “The following past and present projects provide working examples of our value engineering solutions.”

Left to right (front): Stoney Moshe (piling banksman), Joshua Tshauke (piling operator) and Aubrey Modike (senior piling foreman), together with Pilecon director Hugh Feely (back)

Tembisa Water Tower A new 40 m elevated water tower in Tembisa required a piled foundation to withstand high compressive and uplift forces.

Pilecon was contracted by Zidlaphi Kgomo & Associates to install 750 mm and 600 mm diameter, combined friction and end bearing, auger cast in situ piles to depths of up to 20 m below ground level.

Tsakane Reservoir Pilecon was contracted by Nkomaba Trading & Projects for the new 39 m diameter Tsakane reservoir south of Johannesburg. The site is underlain by highly variable andesite bedrock, which has weathered to a clayey soil, containing large residual corestones and an undulating hard rock profile beneath the soils.

“The soils are saturated, with a groundwater table located at shallow depth, thus proving to be too soft to carry the load imposed by the reservoir on conventional foundations,” says Van Straten.

The pile design dictated that 900 mm diameter piles be installed to carry loads of 3900 kN

Petrus van Straten, director, Pilecon

COVER STORY each. In view of the ground conditions, the piles needed to be cased through the soft waterlogged soils down on to the bedrock and then hand cleaned to ensure complete end bearing. Pile depths varied across the site from 3 m to 18 m below platform level and each pile was tested by PIT-type integrity test methods. This was followed by random core drilling through the centre of selected piles to prove a positive contact with solid bedrock.

Eikenhof Rand Water Dosing Chamber Pilecon was contracted by Delmon Mining & Civils to design and install a soil nail solution for two 6 m deep vertical faces at the Rand Water Eikenhof Waterworks site. This made provision for the construction of a concrete dosing chamber over an existing 2 m diameter water pipeline.

The contract involved the installation of soil nails in very tight spaces between the pipeline, the Eikenhof access road and existing structures. As a result of a lack of geotechnical information of the site area and the presence of groundwater, it was necessary to monitor and adjust the design spacing and lengths of soil nails as the works progressed. The soil nails were installed in a 1 m grid pattern to lengths of up to 8 m behind the shotcreted face, to provide temporary retaining walls and allow a safe working environment for the chamber construction.

Commercial projects ArcelorMittal Vanderbijlpark Works The new Coke Ovens By-product Plant at Vanderbijlpark is located within the ArcelorMittal plant and is underlain by dolerite and sandstone bedrock with a thick mantle of saturated residual soils not suitable for conventional shallow foundations.

A piled solution was recommended and Pilecon was awarded the contract to install 650 no. temporary cased 600 mm diameter auger cast in situ piles to depths of up to 15 m for the various structures. In certain areas, existing overhead structures precluded the use of large auger rigs, which resulted in the pile design being altered to incorporate groups of micro-piles using Pilecon’s Comacchio MC 800 rig in rotary percussion drilling mode to install 203 mm diameter piles.

PILECON GEOTECHNICAL SERVICES • Geotechnical investigation • Auger piling • Lateral support • Micro-piling • Self-drilling anchors (SDAs)

JK 580 rig installing soil nails at Eikenhof

Komatsu Reman Plant Edenvale Piling for the new Reman Plant at the Komatsu Edenvale site was only specified after the main contractor, Abbeydale Construction, had already started with excavation of pad footings. Pilecon was required to install 199 no.

13 m deep, 600 mm diameter piles within the excavations in as short a time as possible, so as to claw back delays in the construction programme.

Two Soilmec rigs were put on-site and the piling was completed within 12 days to the complete satisfaction of the client.

Corkwood Shopping Centre, Uitenhage The geology of the Uitenhage area is complex and particularly so in the area adjacent to the VW plant at the site of the new Corkwood Shopping Centre. The geotechnical report compiled by Geo Simplicity informed the design of the piling to the basement parking portion of the centre. Pilecon is in the process of installing 250 no. piles ranging from 450 mm to 750 mm in diameter, to depths of up to 11 m, penetrating bouldery alluvium and mudstones of the Kirkwood geological formation.

Micro-piling for specialised structures City Power Monopole Foundations The Fleurhof Roodepoort electrical reticulation for overhead high-voltage lines required tall monopoles to be erected in confined spaces. Therefore, conventional large concrete foundation bases could not be used for the pole foundations.

An alternative design was implemented using SDA piles. Pilecon was appointed by electrical contractors Tshwalec to install the piles. Up to 26 no. SDA piles per base were required to anchor the foundations of four monopoles.

The SDA technique uses a sacrificial hollowstem drill rod and drill bit to install the anchor, which is then grouted solid into the soils and rock beneath the monopole base. The SDAs support the compressive and tension loads imposed by the monopole over a very small plan area.

Pilecon’s R412 and R515 Soilmec rigs working at the Komatsu Reman Plant site in Edenvale, Gauteng

Chicken Licken at The Grove, Nelspruit An existing restaurant situated at the top of a 6 m high retaining block wall was to be converted to a Chicken Licken outlet with a drive-through between the building and the edge of the retaining wall.

The extension for the drive-through left a 2.5 m corridor for the installation of piles to carry the structural loads. Pilecon’s Hutte HBR 203 mini-rig was used to install SDA micro-pile groups along the narrow corridor. The Hutte rig has an independent power pack, which stands 30 m away from the drill rig and allows for entry into very tight spaces for pile installation.

Bokomo Silos, Gaborone Two new, 20 m high storage silos were required at Bokomo Gaborone. The residual granite soils beneath the site have a high water table and overlie an undulating bedrock surface.

SDA-type piles were chosen for ease of installation, eliminating the need to install temporary casings.

Using the Hutte rig with a top drive percussion hammer, Pilecon installed the 36 no. piles required in a total of three days.

“We have the flexibility to tackle projects of any size or complexity within South Africa and cross-border, working with the client and professional team to engineer the optimum foundation and support solutions,” Feely concludes.

www.pilecon.co.za

IMIESA May 2020

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THOUGHT LEADERSHIP

Establishing an effective and participative construction sector Infrastructure spending sustains and builds economies. IMIESA speaks to Cyril Gamede, CEO, Construction Industry Development Board (CIDB), about the strategic role of the public sector’s infrastructure regulatory body.

What is the CIDB’s mission and vision for the construction industry?

CG The CIDB’s vision is the establishment of a transformed construction industry that is inclusive, ethical and contributes to a prosperous South Africa, and the world. Within this context, our mission is to regulate and develop the construction industry through strategic interventions and winning partnerships.

Cyril Gamede, CEO, CIDB

How will this influence the CIDB’s current and future mandate?

The current mandate does not include the regulation of professionals and suppliers; however, for proper development of the industry, one must look at ways of intervening in these areas.

The infrastructure project pipeline is drying up. How can we revitalise the industry?

This can only be achieved through strategic interventions and partnerships.

The projects are initiated by government departments, SOEs, municipalities, etc. There must be innovative ways of intervening and partnering with stakeholders at these early stages to ensure that the pipeline of projects has a near-constant flow.

Funding has not been the issue; instead, it is employment. The Auditor General’s office has clearly outlined key challenges within the SOE and municipal space.

Procurement delivery has been affected by corruption, major project cost overruns, as well as misunderstandings about what should be specified in tenders when it

KEY CIDB MANDATES Among other priority areas, the CIDB is tasked with promoting: • Uniformity in construction procurement • Efficient and effective infrastructure delivery • Construction industry performance improvement • Development of the emerging sector, including industry transformation • Skills development

comes to designated CIDB gradings. Our objective as the CIDB is to ensure that these entities have a clear comprehension of which CIDB gradings need to be specified. That’s essential, in part, to unlocking administrative bottlenecks. We also commit to ensuring that all companies registered with the CIDB are competent to perform the work.

System constraint examples include poor operations and maintenance planning, the lack of capacity to develop projects from concept to construction, human capital budgeting limitations, and the lack of effective and efficient technical departments and project management units.

THOUGHT LEADERSHIP

What were your takeaways from SONA? First, cutting the business red tape is essential, since we all know that the current bureaucratic processes hamper the ease of doing business and create major procurement delays.

It’s also clear that a coherent plan is needed for Eskom, which is unfolding.

Construction projects are dependent on investments, which are also dependent on power availability.

An upswing in independent power producers and the ability to produce for one’s own consumption will further improve investment.

The R1.6 billion committed for rail infrastructure is welcomed, as is the R700 billion earmarked over the medium term for student accommodation, social housing, water services, electricity, municipal bulk infrastructure, and broadband roll-out.

However, a major impediment to service delivery is the fact that too many municipalities are failing. So far, there are 139 interventions imposed on 40 South African municipalities. The root causes are due to failures in executing both maintenance and capital projects.

What are the historic challenges and solutions for SMME growth?

The construction sector is a highly competitive environment. In fact, it has always been a bit of a cutthroat business, with the lion’s share of the market dominated by top-tier contractors. That has always made it challenging for any new entrants, and today that especially applies to black-owned businesses.

The CIDB’s mandate is to address and correct this.

I was involved with contractors at a very early stage in my career and witnessed this competitive culture first-hand; however, there were no black contractors then. I remember introducing the first black contractors during a project in the first company that employed me in Durban, in the early 1990s. There was so much resistance from some white foremen and contractors. I provided the new black contractors with close supervision, for their protection and mine.

I remember supporting a welding contracting company that was formed by two black welders. They originally worked under an established white contractor and later decided to venture out on their own. They subsequently became very successful contractors and later expanded into other businesses as well. One became both a successful businessman and politician, eventually becoming a mayor. They overcame massive odds.

The important point to make is that SMMEs must be given a chance to showcase their skills, which is a CIDB priority. At present, the space is flooded with middlemen who hamper the proper implementation of development, so that needs to be addressed.

How has industry responded to the revised grading limits?

We’ve received widespread support from industry following this move.

Increasing the tender value limits on projects presents new opportunities for contractors across the grading spectrum.

Has real progress been achieved in terms of transformation and womenowned businesses?

The participation of black contractors

remains a challenge, especially in higher grades. Increasing the participation of woman-owned businesses is an even greater one. In fact, their participation is regressing, so proactive steps must be taken to improve this situation.

The 2017-enacted 30% amendments of the Preferential Procurement Policy Framework Act (PPPFA; No. 5 of 2000) have not been fully taken advantage of.

In fact, a frequent misinterpretation is that it has resulted in negative gains.

What are your views on procurement and the definition of local contractors?

We continue to emphasise that the reference to ‘local’ in the PPPFA refers to South Africa, and not to a specific community, city or town. The 30% objective should be regarded by top-tier companies as a partnership opportunity that mentors and sustains SMMEs. What are the immediate priorities?

The most pressing challenge is the weak construction pipeline. After that is the need to develop and move lower CIDB grades up the scale so that they can gain traction and contribute meaningfully to GDP from a micro- and macroeconomic perspective. SMMEs are particularly in need of affordable access to finance.

Funding support for training is another area we are exploring. Combined with this, we would like to see CIDB 8 and 9 grades (our uppermost tier) apportioning more time for the practical on-site training of SMMEs. In response, we have increased the amount that can be claimed by contractors for this purpose.

We know that times are tough, and that securing new tenders has become much harder, given the intensified competition for work. This motivated the CIDB to impose a moratorium on the downgrading of contractors not awarded public sector projects within prescribed periods.

Together, we must find ways to accelerate transformation, but even more importantly, we must upskill and empower today’s and tomorrow’s entrepreneurs. For that to happen, approved projects need to be mobilised nationwide.

IMIESA May 2020

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ROADS & BRIDGES

There is a right and a wrong way to approach labour-intensive construction (LIC) projects in South Africa. Devan Govender, technical executive: Economic Development at Naidu Consulting, comments on the company’s experience.

By Alastair Currie

T

he application of LIC techniques is well established globally and has gained some traction in South Africa, particularly on Expanded Public Works Programme (EPWP) projects. As an employment enabler, LIC creates muchneeded jobs, particularly in rural and peri-urban communities. At the same time, it establishes the critical infrastructure required to connect communities to the mainstream economy, as well as creates access to clinics, schools and hospitals.

Although LIC has tremendous merit, it still receives a measure of resistance from designers, contractors and public sector entities.

Arguments are presented that mechanisation is clearly faster and more efficient, and that relying on labour unnecessarily extends project timelines and increases costs.

“These objections are based on misunderstandings about how the LIC process

Bringing the community on board works, largely because there’s a common practice of applying it as an add-on to a project with mixed results,” Govender explains.

“To ensure success, LIC must be part of the design process from inception, and that will determine the scale and scope based on the type of project selected. It’s equally important to work with a contractor that embraces LIC. The wrong contractor will fight the process from day one,” Govender continues, adding that road works are particularly well suited to LIC interventions.

Some years back, Naidu Consulting took the conscious decision to keep LIC top of mind when designing work for public sector clients. “Even where LIC is official policy within government departments, it needs a champion to drive and support it strategically, combined with willing participation from the bottom up,” he continues.

“Even then, project and programme management must be executed by those with expert knowledge and experience.”

Since these are projects for and by the community, their commitment and participation must be gained well before project inception.

That is vital. Building trust and enabling ownership of projects also go a long way towards minimising site disruptions and ‘construction mafia’ interference.

Naidu Consulting’s D1613 upgrade project for the KwaZulu-Natal Department of Transport

Naidu Consulting’s design made provision for the bulk of the excavation to be carried out by hand to the final level

Construction of the D1613 concrete surfaced district road using multi-cells

Graduation day: each trainee received a CETA-approved NQF Level 2 qualification

community workers moved more than 32 000 m3 of soil and placed more than 600 m3 of concrete.

The design catered for the additional supervision required due to the increased number of unskilled labourers. And to ensure capacity development and skills transfer, classroom and practical training programmes were conducted.

Conventionally, training is undertaken during EPWP projects; however, in an innovative approach, Naidu Consulting negotiated with all stakeholders that training be undertaken prior to construction. With the permission of public schools in the area, participants were trained on the premises.

During the practical training component, they were required to upgrade the schools’ highly deteriorated driveways using the multicell methodology. This was done to mimic the proposed road conditions and to ensure that the necessary task rates were confirmed.

Since these were left as permanent structures, there was a dual benefit. Each trainee received a CETA-approved NQF Level 2 qualification and candidates were identified for future contractor training by the KwaZulu-Natal Department of Transport.

RockDrills

Distribution and Product Support by:

Engagement is a classic example of how LIC can build infrastructure and empower communities. The project won a Highly Commended Award at the 2018 SAICE Awards.

Hand-made D1613 entailed the establishment of a 3.6 km concrete surfaced district road allowing access to the main road in Ndwedwe (P100), which is situated approximately 60 km north of Durban.

Phase 1 was registered as an EPWP project and entailed the establishment of a Type 6 road together with applicable geometric design improvements to the horizontal and vertical alignments, which previously consisted of a highly eroded gravel wearing surface.

On the D1613, Naidu Consulting’s design made provision for the bulk of the excavation to be carried out by hand to the final level, plus the installations of gabions and concrete placement. The road was designed to ensure that construction was implemented using multicells. This decision was taken to guarantee the optimisation of local labour and was supported by a feasibility study.

The implementation, using local labour resources, also meant that the project would address the high poverty and unemployment factors within the community. During the project,

Naidu Consulting engaged the community early on, explaining the rationale. Since this was Phase I of the project, the community was also invited to identify priority sections that could be addressed on the imminent contract.

Even more significantly, Naidu Consulting also reached a collective agreement, through wage negotiations with the community, on the EPWP daily labour rate, to maximise the number of people employed. As a result, an astounding 36% of the construction budget was spent on community wages.

Of the approximately 260 community members deployed, more than 60% comprised women and youth. Naidu Consulting ensured that a fulltime representative was on-site to manage the LIC process.

“While a key portion was manually excavated, we’d already predetermined that some sections would require mechanical techniques, which had been explained to the community. These included hard ground zones where some 13 000 m3 was removed by machine. However, in all other respects, manual techniques constituted most of the works,” he adds.

“On any LIC project, engineering flexibility is key. You can’t take a blanket approach. LIC is about people and not statistics – and when applied well, yields exceptional outcomes,” Govender concludes.

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ENVIRONMENTAL ENGINEERING

The art of gabion construction Frequently constructed using in situ materials, or commercially blasted rock, gabions blend in well, providing strong aesthetic appeal in a wide range of applications, extending from embankment and abutment retaining walls to river erosion works. However, although they appear simple, their design and construction require highly specialised skills and experience. By Alastair Currie

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s retaining and erosion control systems, gabions provide an endless range of flexible solutions. This is especially the case when it comes to sustainable urban drainage interventions designed to significantly reduce stormwater run-off velocities.

Left unchecked, stormwater torrents result in extensive river erosion and downstream impacts that include sediment build-up in dams, and damage to bridge and culvert infrastructure. Water capture and storage is also a critical intervention in sustaining wetland systems; here, modern-day gabion attenuation ponds play a crucial role.

“In the majority of these cases, environmentally engineered solutions using gabions and gabion mattresses are the best response,” explains Louis Cheyne, managing director, Gabion Baskets. “However, this is 1

not a ‘do-it-yourself’ intervention, despite the fact that we still see examples in the municipal and private space where some awarded projects are completed by inexperienced contractors with mixed results.

“No project should commence unless it has been professionally designed, detailed, specified and costed following a site inspection that includes a geotechnical and hydraulic survey,” he continues. “Amazingly, some work is still authorised unseen and without a detailed bill of quantities.

When these contractors run short on funds to complete the work, they then sometimes use the cheapest options, with substandard results.”

Gabions and their associated derivatives, like gabion mattresses and sausage gabions, are made from hexagonal, doubletwisted mesh wire that needs to conform to SANS 1580 in terms of dimensions and 3

aperture configuration. The mild-steel wire used must additionally comply with SANS 675 or equivalent.

Where corrosion is a factor, the next highest specification is Class A wire with a Galfan zincaluminium alloy coating. Wire systems can also be PVC coated for aggressive applications where abrasion and/or corrosion is a factor – a prime example being the gabions used within a riverine environment. Gabions formed using standard Class A galvanised wire with PVC coating have an estimated design life of 60 years, while Galfan PVC coated wire can last for up to 120 years.

Typical specification and installation errors to avoid As Cheyne points out, wire selection is important for overall longevity, but is interdependent on how gabion systems are constructed. The best design is only as good

GABION FILLING The gabions should be filled with rocks of size 100 mm and 250 mm, not smaller than the mesh size: 1 The filling should take place in 3 layers of 300 mm for 1 m high gabions and 2 layers of 250 mm for 0.5 m high gabions.

2 The rocks should be packed tightly to avoid settling or bulging during and after installation.

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3 At the top of every layer 300 mm, bracing wires are necessary to avoid undesired settlement or bulging of the gabion. Gabions of 1 m height will have bracing wires at onethird and at two-thirds of the height. Gabions of 0.5 m height will have bracing wires at one-half of the height.

4 After filling the gabion, close and fix the lid using 2.2 mm lacing wire or approved hog rings. A suitable closing tool (as shown) can also be used.

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ENVIRONMENTAL ENGINEERING Baskets to be erected in accordance with SABS 1200DK or contact supplier

Backfill compaction behind wall to be 93-95% MOD Aashto in 150 mm layers

2 m wide river mattress apron for erosion protection at toe of wall

For walls higher than 4 m base baskets must be layers of 0.5 m gabions

Base width to be 55-60% of height of wall, dependent on soil conditions

as the installation techniques employed, which places a heavy emphasis on training. This is especially important on Expanded Public Works Programmes where unskilled labour is sourced from local communities.

The selection and correct packing of rock is essential to achieve form and function. Being naturally permeable, the design should also consider whether a geotextile liner needs to be installed. An example would be a retaining structure where soil erosion behind the wall must be minimised to prevent undermining.

Other aspects to consider include: • Poor material choice – e.g. discarded brick materials that don’t have the desired durability compared to rock.

• The wrong wire specification or using a non-compliant wire that is guaranteed to fail prematurely.

• Incorrect product selection – e.g. the use of welded mesh gabions in a river application.

Hexagonal, twisted-wire mesh is meant to flex, but welded mesh – which is intended for architectural applications – isn’t, being flat and rigid by design for use in internal and external wall and allied cladding roles. When used in a river, welded mesh will eventually fracture and destabilise the rock fill and subsequently the overall structure.

• No design adjustments for difficult site

Geotextile A4/F-34 to be joined in 300 mm overlaps

situations and changes, like marshy ground or seasonal flood plains.

• No or poor supervision related to work done, with ensuing failures.

• Lack of on-site gabion layout and installations experience. This especially applies to rock packing and the critical aspect of correctly lacing each filled basket together to form a holistic system. Baskets and mattresses are traditionally laced with Class A wire in the specification selected for the job; however, a more advanced option is the use of clip rings that greatly speed up productivity in the hands of a skilled worker.

It is strongly recommended that contractors run practical training courses on-site, and that all works are project-managed and executed by an expert installer working with a specialist professional engineer. Gabion Baskets provides site assessment and structural design assistance, plus training at all levels to facilitate with this process, including seminars aimed at the consulting engineering profession.

“Providing technical advice can be a real eyeopener, especially when we’re invited to give input on active projects where inexperienced contractors have run into difficulties.

Sometimes, the best advice is to start from scratch but, this time, with an environmentally engineered approach,” says Cheyne.

The importance of compaction and battering A properly designed gabion structure does not require a concrete foundation, irrespective of its height. The key to achieving this is to ensure that the base is wide enough in relation to the height, using standard formulas. The foundation also needs to be compacted efficiently to a predetermined MOD Aashto density, which will be influenced by the underlying soil type.

Compacted samples need to be verified in a certified soil laboratory.

The general rule is that the depth of the foundation needs to be at least 10% of the height of the structure. For example, a 10 m high retaining wall (above ground) needs to be founded to a depth of 1 m. Another mandatory factor is the battering of the wall by 6 degrees (achieving a 150 mm drop at the back of the structure for every horizontal metre) for vertical facing walls. Constructing the wall in this way ensures that it leans back into the embankment to increase the factor of safety against potential overturning and failure.

“More emphasis needs to be placed on environmental engineering within the civils programmes offered at South African universities, as there is massive potential for cross pollination within these interrelated disciplines,” says Cheyne.

A classic example is the increasing adoption of military surplus Bailey bridges for gulley and river crossings within South Africa’s remote rural communities. Forming the abutments in concrete is one option; another is to go the gabion route – something that a conventionally trained civil engineer might not have considered.

Gabions are labour-intensive and ideally suited for community-based projects. Once gabion abutments are competed, they are designed to take live loads immediately. In contrast, concrete requires skilled artisans, steel fixing and specialist formwork. Concrete also has a minimum 7- to 10-day setting and hardening time.

“Available budget spending is limited, while our infrastructure priorities are countless.

Additionally, we need to fill major skills gaps in South African construction and, to do this, engineers and specialist suppliers have a greater role to play in mentoring and training. I believe that needs to be stipulated in all tender documents. It will help prevent cost overruns, wastage and rework,” Cheyne adds.

“For every job, we need to find the most creative and sustainable solution. In this respect, environmentally engineered structures are a perfect fit,” Cheyne concludes.

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ENVIRONMENTAL ENGINEERING

Geomembranes offer ideal dam solution High-spec, high-tech dam liners outperform conventional containment methods by a wide margin.

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hen the integrity of dams and other water storage facilities is compromised, the socio-economic impact on entire towns and regions can lead to significant implications for residents and local municipalities.

Many ageing earth dams were built before the introduction of HDPE and LLDPE geomembranes as liners. Instead, conventional building materials, such as clay, were applied as a seal. Today, modern geomembranes provide greatly improved performance.

Geomembranes are also thinner, faster and therefore less costly to install.

Utilising thin Geoliner (1 mm or 1.5 mm) – instead of a thick, compacted clay layer – significantly increases the water carrying capacity of a dam.

For these reasons, and the following considerations, geomembrane liners such as AKS Geoliner remain the optimal choice for various containment applications, particularly in the rehabilitation and new builds of dams and reservoirs.

AKS Geoliner AKS Geoliner is characterised by its exceptional durability, high chemical resistance, UV protection and superior weldability. The material’s excellent tensile properties and high elongation characteristics – combined with flexibility – make for a tough, watertight seal that is resistant to tearing and puncturing.

At the same time, AKS Geoliner is flexible enough to allow for easy installation without compromising integrity.

AKS Geoliner is resistant to root penetration, termites and moles. The material’s weldability results in a durable, homogeneous fusion of the sheets, which allows for ease of on-site quality control.

Geoliner is manufactured using the calendered ‘flat-die’ extrusion process, in 7 m widths with thickness ranging from 1 mm to 3 mm. It is available in HDPE and LLDPE, with a smooth or textured finish, or a combination of smooth and textured, either on one or both sides of the sheet.

To ensure a consistent product with the highest level of accuracy, AKS liners are manufactured using European-made precision extruders.

Geoliner can be custom-made to suit specific project requirements, considering installation needs, roll lengths, and truck and container loading configurations.

When it comes to handling, each roll is fitted with two lifting slings to facilitate offloading and moving the product on-site.

Quality guarantee AKS Lining Systems is an ISO 9001:2015 accredited company. It follows a strict code of conduct to ensure top quality products. The company’s state-of-the-art laboratory ensures that all Geoliner meets For further information, visit aks.co.za, email info@aks.co.za or call +27 (0)21 983 2700.

AKS invites its customers to arrange a plant visit to familiarise themselves with the integrity and quality standards employed at the company.

Peter Hardie, International Technical Sales Manager, AKS

or exceeds international standards such as GRI-GM13 (HDPE), GRI-GM17 (LLDPE), as well as the local SANS 1526. During the manufacturing process, continued pinhole detection is applied across the entire width of the sheet, providing in-line quality inspection.

An in-line marking system ensures on-site quality control and traceability.

Instead of relying on a mere sticker or label to identify the brand and batch, a line indicating the wedge weld overlap width, 150 mm from the edge, is printed every linear metre, together with the roll number. The roll number is linked to the AKS quality control system and provides manufacturing information such as the resin used, the master batch, the responsible operator and the MQC certification details. In large installations, the number is entered in a panel layout to provide a record of every square metre of lining used in the dam.

AKS Geoliner is manufactured at the company’s modern, large-production capacity plant in Brackenfell, Cape Town.

A yard with ample storage provides the shortest possible lead times to customers.

aks.co.za

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BUILDINGS

Face brick adds vibrancy to Noordgesig Primary School The newly constructed Noordgesig Primar y School opened its doors to 1 800 pupils in 2020. Par t of the school structure was built using Corobrik’s face brick range.

Corobrik face bricks were used in the construction of the administrative building and school hall at Soweto’s Noordgesig Primary School

(Credit: Yikusasa Building Contractors)

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oordgesig Primary School was officially opened at the start of the 2020 school year by Gauteng Premier David Makhura, alongside Gauteng MEC for Education Panyaza Lesufi, and MEC for Infrastructure Development and Property Management Tasneem Motara.

Material of choice For Noordgesig Primary School, 84 000 Firelight Travertine and 48 000 Golden Wheat Travertine face bricks were used in the construction of the administrative building and school hall. The total project cost around R110 million to complete, funded by the Department of Education as an end user and implemented by the Department of Infrastructure Development.

Other stakeholders involved in the project included the TPM Consortium, Lethola Cost Assoc. & Qs, Masa Consulting, Tribe Architects, the City of Johannesburg, Ralph Engineering and Yikusasa Building Contractors.

Kenneth Masvikeni, principal architect of Tribe Architects, the organisation tasked with designing the new structure, chose to use Corobrik’s face brick range for the school’s administration block and hall. The school replaced the previous asbestos building and is now a modern, information-technology -based facility.

“Corobrik’s Firelight Travertine and Golden Wheat Travertine were chosen to fit in with the surrounding landscape consisting of rolling dunes,” explains Sebastian Adams, quantity surveyor at Yikusasa Building Contractors. “The brick is incredibly low maintenance, which is beneficial for long-term government investments.”

The ideal solution Commenting on the choice of face brick, Musa Shangase, commercial director at Corobrik, says: “The Corobrik clay face brick selection has proven to be the ideal material for government infrastructure projects over the years. When it comes to school buildings such as the impressive Noordgesig Primary School, government departments are able to deliver a high-quality project, boasting worldclass structural and aesthetic integrity, while promoting comfort and a low life-cycle cost.”

Because face brick doesn’t require plastering or painting, there are long-term cost savings related to maintenance. In addition, the clay brick offers enhanced thermal comfort by retaining warmth in winter and creating a cool interior in summer, minimising the need for artificial temperature regulation and keeping learners comfortable.

“Schools – particularly large primary schools such as this – are busy places with lots of noise. This is another area where Corobrik’s face brick is so beneficial – the advanced acoustic properties mean that children are not being disturbed by noise when studying,” adds Shangase.

In line with government’s focus on sustainable infrastructure, Noordgesig Primary School was also constructed with several green design features. These include: fenestration, which maximises natural light and air circulation while reducing energy loss from the building; energy-saving lighting; and solar water heating throughout. Alongside the indigenous trees used in the landscaping, there is an attenuation pond housing greyand stormwater, which will be used for filling toilets if needed, washing cars and watering grass.

BUILDINGS

Ecobricks on a commercial scale

The ecobricks were donated by community volunteers and scholars from Cape Town’s suburbs, with quality control undertaken on-site by the main contractor (Credit: Gareth Griffiths) The bricks are placed vertically in the 300 mm deep void area and covered with concrete (Credit: Gareth Griffiths)

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ccording to Green Building Council South Africa, the construction and operation of buildings globally contributes to more than a third of all greenhouse gases. This clearly motivates the need for the application of alternative materials and techniques to lower the carbon footprint.

Within the mix, the use of ecobricks is gaining ground, championed by organisations such as the Global Ecobrick Alliance. Each ecobrick is a plastic soft drink bottle filled to constant density with other waste plastics – such as chip packets, sweet wrappings and shopping bags – all

South Africa

of which would otherwise have been sent to landfill.

A local example is their partial incorporation as void formers during the construction of The Ridge, a new commercial development in the Portswood District at Cape Town’s V&A Waterfront. It will serve as Deloitte’s regional office.

“To the best of our knowledge, The Ridge is the first large commercial building in the world to do this,” says Mark Noble, development director, V&A Waterfront.

The ecobricks have been used in the concrete slabs for the central toilet areas on each floor. The total void volume in the

entire building is 41 m3, which equates to approximately 12 500 ecobricks. Each bottle has a mass of approximately 418 g, resulting in 5.2 tonnes of used, single-use plastic being reused.

By using material already manufactured, the project saved 30 t of CO2. This equates to taking 6.5 passenger vehicles off the road for a year.

“Together with our various other established recycling programmes, which include a substantial quantity of the building waste from the SILO project, these techniques make a vital contribution to the circular economy,” Noble concludes.

HUMAN SET TLEMENTS

Giving land to the people

The Department of Public Works and Infrastructure has released several parcels of land for human settlements development and calls on other government departments to do the same. By Danielle Petterson

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uring October 2019, the Department of Public Works and Infrastructure (DPWI) released 14 105 ha of land for human settlements development in the Eastern Cape, Gauteng, KwaZulu-Natal, Mpumalanga, North West and Western Cape. This was followed by an additional 20 parcels of land in 2020.

Addressing delegates at the recent CESA Infrastructure Indaba, Minister of the DPWI Patricia de Lille said that it is not true that South Africa does not have land for human

Challenge to government settlements and stressed that cheap land far from cities should not be used to build houses for the people.

“The land that I’ve released for human settlements is well-located, well-connected land that can bring our people closer to work opportunities,” she said.

The DPWI is currently assessing 147 pieces of land that will be released to the Department of Agriculture, Land Reform and Rural Development for agricultural use. The department is also in the verification process of 102 land parcels for land restitution.

Salvokop development

Patricia de Lille, Minister of the DPWI

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urban sprawl and bringing communities closer to government services.

The DPWI procured the land for the first precinct development in Salvokop from Transnet for R79 million. Under Phase 1, four government head offices will be built at Salvokop for the Department of Correctional Services, the Department of Higher Education and Training, the Department of Social Development together with SASSA and the National Development Agency, and lastly the Department of Home Affairs.

Stats SA has already built its offices in Salvokop, making it the first property to be completed in the precinct. The flagship development of 56 000 m2 was successfully completed in 2016.

Phase 1 of the Salvokop project is expected to contribute an estimated R6.5 billion of blended financing. National Treasury is assisting the DPWI with accessing government grants and the department will also be applying for funding from the president’s R100 billion Infrastructure Fund.

De Lille highlighted the new Salvokop Development Precinct to be established in Pretoria. This mixed-use development will drive integration and act as a catalyst for private sector investment and, according to De Lille, three publicprivate partnerships have already been registered with National Treasury.

The project forms part of the Tshwane Inner City Regeneration Programme and aims to help reverse the legacy of apartheid spatial planning by stopping

According to De Lille, the land released by her department to municipalities for human settlements development was done so with the stipulation that it may not be sold. She noted that, in some cases, municipalities sell their own well-located land and later ask national government for land for development.

“We must be able to see the immovable asset register of all three spheres of government because we are one country,” she stressed.

De Lille went on to note that there has been no digital immovable asset register at a national level, which she calls an indictment after 26 years of democracy. The minister will therefore be launching the country’s first digital immovable asset register in June 2020.

De Lille noted provincial governments and municipalities are sitting on a lot of land and buildings. “I make a plea to all three spheres of government: don’t sit on your well-located land; release that land.”

She noted that if government departments release well-located land for land redistribution, restitution and tenure, debates around land expropriation without compensation, which is already accommodated in the Constitution, can be avoided.

“When it comes to land and governmentowned buildings, it must be used for the public good.”

City of Cape Town Investing in the future

INSIDE Reigniting the Cape economy

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Inclusive housing at scale

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Growing South Africa’s digital economy

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Water and wastewater pumping excellence

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Treatment expertise perfected

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Making sludge sustainable

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Virgin plate glass media revolutionises filtration 29 Zandvliet’s mega expansion showcases excellence

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Pursuing carbon neutrality

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CITY OF CAPE TOWN

Reigniting the Cape economy The City of Cape Town is responding to the socio-economic impacts flowing from Covid-19 with a multipronged approach that will benefit all sectors, including construction and tourism.

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stablishing the framework for a post-Covid-19 recovery, the City of Cape Town’s Development Management Department has been open for business since the start of the national lockdown, approving building plans to the value of R2.3 billion between 27 March and 14 May 2020.

“The construction industry employs hundreds of thousands of workers and we want to see the smaller contractors and builders, in particular, returning to building sites as soon as the situation allows for it,” says Alderman Marian Nieuwoudt, MMC for Spatial Planning and Environment, City of Cape Town.

During the period, 1 374 building plans were approved for works less than 500 m² at a combined value of approximately R850 million. Above 500 m2, 63 building plans valued at some R1.2 billion were approved. The remaining R250 million comprised 379 minor work applications.

As South Africa entered Level 4 of lockdown, construction activities on subsidy housing and informal settlement projects started to come back online. “Work on the creation of healthier spaces in very highly populated informal settlements carries on in an effort to reduce the rate of Covid-19 infection,” says Councillor Malusi Booi, MMC for Human Settlements, City of Cape Town.

“The city is supporting the Western Cape and national governments in efforts to relocate residents amid the health crisis.

Plans are also being finalised for enhanced Covid-19 services in priority public housing developments and hostels,” he continues.

Financial adjustments Municipalities across the board are feeling the financial squeeze, given the sudden halt in non-essential business activity from late March. Salary cuts and job losses have compounded the problem, placing massive pressure on most households. At the same time, towns and cities have had to deal with unexpected expenses flowing from rigorous new health and safety protocols.

In Cape Town’s case, the city has adjusted its current 2019/20 budget (ending June 2020) to cover R386 million in ongoing additional expenditure due to the Covid-19 crisis and an income drop of approximately R860 million since the national lockdown commenced at Level 5. This loss includes income from rates and tariffs, MyCiTi public transport fares, the suspension of events by the Cape Town Stadium and Cape Town International Convention Centre, and parking and development fee decreases, among others.

“The Adjustments Budget (2019/20) clearly shows the Covid-19 crisis is not a once-off disruptive event. It will have longterm impacts on the city’s operations and programmes, its income sources for service delivery, and on the general socio-economic welfare of its residents and ratepayers,” states Executive Mayor Dan Plato.

Cape Town International Airport (CTIA) was judged the best airport in Africa, for the fifth time in a row, at the recent Skytrax World Airport Awards. According to ACSA, around 10.9 million passengers transited CTIA during 2019

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Some of the key adjustments and additional expenditure for the current financial year (2019/20) include: - reprioritisation and rephasing of projects and programmes - shifting funds within directorates – an example is the R63.5 million allocated for the provision of water and sanitation to informal settlements - enhanced cleaning of homeless shelters and informal settlements - cleaning materials such as hand sanitisers, chemicals to disinfect floor areas at public transport interchanges and bus depots - humanitarian relief.

A thorough expenditure analysis was performed by city line departments on all expenditure items/programmes in the current 2019/20 operating budget. This exercise revealed underexpenditure of R1.2 billion.

The city says these savings will be used to absorb the impact of the Covid-19 pandemic in the current financial year.

Economic revitalisation Ahead of the 2020/21 financial year, commencing 1 July, the city’s Economic Action Plan is mapping out the threats and opportunities going forward. Attracting local and foreign direct investment will be key, as will rebuilding critical local industries like tourism. Interlinked with the latter are plans by Airports Company South Africa (ACSA) to further expand Cape Town International Airport, as well as the city’s planned Aerotropolis development.

ACSA upgrades, valued at an estimated R8.38 billion, include a new realigned runway, a new domestic arrivals section, and an expansion to the current international terminal.

CIT Y OF CAPE TOWN

Inclusive housing at scale To address urbanisation and the housing crisis, the City of Cape Town is committed to creating a diverse range of housing opportunities.

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he increasing demands of urbanisation and the challenges this brings requires that human settlements become part of the mainstream conversation, says Cllr Malusi Booi, MMC: Human Settlements, City of Cape Town.

“The City of Cape Town believes in a dynamic, innovative, collaborative and inclusive approach to the provision of accommodation across typographies. There is no other way to cater to the extreme urbanisation and to tackle the resulting housing crisis.

“There is a great private and public housing stock demand in the market, and a city government alone cannot create enough housing opportunities. The private sector needs to increasingly come on board to assist in the creation of more affordable housing opportunities and innovative finance mechanisms to do this,” he says.

As it works to reverse apartheid spatial planning, the city is creating enabling opportunities for a wide range of income groups through affordable and inclusionary housing on well-located land close to public transport and job opportunities.

Housing projects Since the 2011/12 financial year, almost 47 000 housing opportunities have been

Bothasig Mitchells Plain Goodwood Glenhaven Demand analysis 2015 (millions per annum)

Start date September 2019 January 2019 September 2019 November 2018 31.3

The R185 million Delft Housing Project will provide 2 400 BNG houses

COVID-19 RESPONSE The City of Cape Town is working to reduce the rate of Covid-19 infection by creating healthier spaces for highly populated informal settlements.

Three sites – in Mfuleni, Philippi and Dunoon – have been identified by national government to create accommodation spaces where essential services are easier to deliver. There are 6 500 relocation sites planned and priority beneficiaries are being identified and engaged.

The city is also enhancing access to water in informal settlements and 31 water trucks have already delivered more than 13 million litres of water to vulnerable communities. Additional cleansing work is also under way at communal facilities.

Planned end date Q2 2021 Q2 2020 Q4 2023 Q2 2020 20.56

No. of opportunities 314 104 1 080 512 12.96

The iThemba site in Mfuleni where accommodation spaces will be created to de-densify informal settlements during the Covid-19 pandemic

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CITY OF CAPE TOWN

Cllr Malusi Booi at the Glenhaven Social Housing Project, which comprises several different types of housing opportunities

One such project is the R185 million Delft Housing Project, which will provide a total of 2 400 BNG houses in the Delft area.

In February 2020, the project reached the 1 227 handover mark.

The city currently also has four social housing developments under development, which, combined, are expected to create more than 2 000 housing opportunities.

Informal settlement upgrades

created and numerous housing projects are currently under way.

The days of following one model of housing delivery, such as state-subsidised Breaking New Ground (BNG) builds, are long over.

Increasingly affordable rental options, enhanced backyarder services provision and the upgrading of informal settlements are being looked at alongside redress typologies such as BNG housing, explains Booi.

“Informal settlements are likely to remain a feature in the city and other urban centres around the country for the foreseeable future due to the urbanisation patterns.

This requires us to come up with innovative ways to uplift our residents in the interim,” says Booi.

As part of the Upgrading of Informal Settlements Programme (UISP), the Kalkfontein informal settlement near Blue Downs is being upgraded at a cost of approximately R76 million, with the provision of toilets, taps and electricity connections for each of the 833 planned serviced sites.

Every household will receive a title deed

or tenure certificate once the upgrade has been completed.

Another UISP project, the Sweet Homes informal settlement upgrade, has been marred by extreme violence. The R90 million project has tragically seen two security guards, a construction worker, eight community members and two law enforcement officers shot dead. “It has been a horror project but the completion of its first phase is testament to the resilience of city staff, of our contractors and of our communities,” says Booi.

The R60 million first phase started in 2017 and is nearing completion. It includes the construction of roads, stormwater and sewer networks, electricity infrastructure, and ultimately a safer space for vulnerable residents.

“We are moving in the right direction with projects such as these, as we need to deliver opportunities at scale to cater for the large housing demand in Cape Town.

Community support and greater private sector partnerships will be the determining factor for success,” concludes Booi.

ACE Solutions can provide you with latest solutions for 5D Bill Production and Estimating By linking your models directly to the elemental estimate and bills of quantities, you can generate an estimate and a bill of quantities at the same time, directly from your model. No need to remeasure from estimating to final account.

With the powerful revisioning engine, bills of quantities can be updated during the construction processes, directly from the model, accurately and effectively. No need to remeasure the same items over and over.

Advance model mapping allows you to generate quantities that are not available in your model and customise your descriptions, to comply to standard methods of measuring.

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CIT Y OF CAPE TOWN | ICT

Growing South Africa’s digital economy In South Africa’s post-Covid-19 landscape, information and communications technology (ICT) will be a vital component in bridging major socio-economic inequality gaps. This requires a comprehensive digital transformation of society driven by private and public sector initiatives, says Steve Briggs, chief commercial officer, SEACOM South Africa.

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cross the world, and now more recently in South Africa, broadband access has become better, faster and cheaper. Investments in local data centres are also making cloud-based services a secure, mainstream choice for a growing number of industries, which include the construction sector and government entities responsible for implementing and managing complex infrastructure delivery models.

“As data volumes rise to unprecedented levels, with a corresponding demand for real-time access of information flows, the way ICT is managed and implemented is critical,” says Briggs.

Going forward, the design, execution, operations and maintenance of infrastructure will be driven across the board by smart technologies. The key question, though, is how many of South Africa’s approximately 257 municipalities have a futureproof ICT policy framework in place, supported by the necessary funding?

Smart cities and smart governments need ICT for initiatives like Wi-Fi roll-outs, traffic management systems, utility automation and remote monitoring, e-services (smart metering/ billing), and financial management and reporting.

“Our commitment as a leading local and international ICT specialist is to create tailored digital platforms backed by our multimillion-rand investment in a national fibre network,” Briggs explains. To date, SEACOM’s South African terrestrial network runs along major arterial routes that include the N1 between Johannesburg

and Cape Town, the N3 from Johannesburg to Durban, and the N7 Bloemfontein to East London leg.

“In subsequent phases, we will continue to expand the fibre ring to ensure that all major towns are ‘lit up’,” says Briggs.

First submarine cable A Mauritius-based multinational, SEACOM launched Africa’s first broadband submarine cable system in 2009 along the continent’s eastern and southern coastline. “Close to two years ago, SEACOM was offering lightning speeds of up to 1.6 terabits per second. We’re now close to doubling that,” he points out, illustrating the pace of ICT advancements. “It’s also interesting to note that a 1 GB per second uncapped line now costs around R15 000 per month. In 2018, it was closer to R70 000.”

SEACOM provides a range of best-in-class enterprise connectivity solutions that extend from high-speed fibre or wireless internet access, to Ethernet links, direct internet access and cloud services. Wholesale data facilities are sold to internet service providers, alongside SEACOM’s direct business-to-business solutions for government and industry.

ICT lag “The so called ‘internet of things’ is shaping our world, increasingly making the smart cities of the future a not-too-distant reality,” Briggs expands.

“Presently, however, South Africa still lags developed and developing benchmarks (India being an example), which presents a threat to our global competitiveness. The upside though is that there are massive opportunities to grow the market, in the process creating new career choices and SMME specialists in the ICT segment.”

Spectrum and 5G One of the next significant ICT developments for South Africa and the world is 5G – ‘G’ standing for generation. 5G will require intensive infrastructure development that may need a combination of public and private sector funding.

In South Africa, for example, this will require a fourfold increase in the density of base stations compared to 4G. Another point to emphasise is that only about 11% of 5G backhaul connectivity will be wireless – with the bulk relying on fibre up to and including the last mile.

“Among cellular providers, the competition for spectrum will intensify and needs to be urgently addressed to ensure fair competition,” says Briggs. Like radio waves, spectrum is all about transmission frequency range, depth and speed.

“Every sector – from health to education and engineering – is dependent on data and connectivity, so South Africa cannot afford to be left behind. Within this context, SEACOM’s mission is to ensure that all individuals and enterprises have access to affordable and scalable ICT,” Briggs concludes.

WATER & WASTEWATER PLANTS

Design • Supply • Maintenance • Repair • Installation

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CIT Y OF CAPE TOWN

Water and wastewater pumping excellence First-rate, well-maintained infrastructure is essential to ensure quality water supply for the increasing population.

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large renewal backlog exists in South Africa’s water sector, of which the largest component is municipal infrastructure such as treatment plants, pump stations and reticulation networks.

Failing pumping equipment, in particular, leads to a deterioration in water and wastewater systems, which causes extreme water loss in many of our municipalities.

With more than 30 years’ experience, HidroTech offers expert knowledge and qualitydriven servicing, repair and sale of equipment for water and wastewater plants.

Hidro-Tech consists of three core divisions – contracting, maintenance of pumping systems and sales. We also offer a complete maintenance service in-house as well as on-site.

Our company has an 8ME CIDB rating and a Level 2 B-BBEE rating – our shareholding is 40% black-owned, of which 20% is blackfemale-owned.

Projects and contracts Hidro-Tech largely concentrates on municipal tender work, focusing on projects such as water and wastewater treatment plants and sewer pump stations.

Our wide range of experience in design, supply, installation and commissioning means

we are able to do large-scale projects across South Africa.

The company has worked on and completed many notable projects and is currently busy with the installation of equipment at the Table Mountain Group (TMG) Aquifer.

As water has become a very scarce natural resource, we should all be actively involved in projects focused on water security.

Sales Hidro-Tech also provides sales and services to a number of industries, such as Industrial, Marine, Paints and Inks, Food and Beverage, Wine, and the Pharmaceutical Sector.

Workshop and maintenance Hidro-Tech operates a fully equipped workshop led by a qualified foreman, with pump fitters and turners. All repair work is performed in-house, with on-site repairs possible where required.

We offer servicing and maintenance on all types of pumps, as well as repairs and replacements on pipework, valves and motors. This also extends to mechanical maintenance work for surrounding municipalities and various other industries.

Our workshop is equipped with a pump

test bay, where pumps and motors can be hydraulically tested. It is also equipped to test borehole, submersible and centrifugal pumps.

The motor control panel is equipped with a variablespeed drive and a data logger that records motor speed, discharge pressure and flow capacities.

Hidro-Tech also holds maintenance contracts with various surrounding municipalities.

IMIESA May 2020

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CITY OF CAPE TOWN

Treatment expertise perfected Established in 1988, Lektratek Water Technology (LWT) is renowned as a leading South African engineering company in the specialised field of sewage and water treatment.

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ne of the reasons for LWT’s success has been its commitment to designing and manufacturing products and solutions that are of a high quality, operate reliably, are long lasting and require minimal maintenance. This core value has earned an excellent reputation with consulting engineers and end users alike and to this day remains paramount in all activities.

LWT is a proudly South African company, with 51% black ownership, of which 30% is blackfemale-owned. The company operates nationwide with offices in the Western Cape, Eastern Cape, KwaZulu-Natal, and in neighbouring Botswana.

The head office, based in Potchefstroom, houses 10 000 m2 of fully equipped workshops.

LWT boasts a 8ME CIDB grading and Level 2 BBBEE accreditation.

“What sets us apart from others is that all designs, value engineering, detail drawings, manufacturing, transport, installation and commissioning are done in-house by permanently employed and experienced personnel,” explains Johan van der Walt, engineering director, LWT. Key personnel have related experience in excess of 25 years in their field. LWT can also offer post-installation services like training, operations and maintenance.

The equipment product range supplied and manufactured is extensive. “We are one of

+27 (0)18 293-0487/8

the few companies in South Africa capable of manufacturing all the conventional equipment related to sewage and water treatment plants.

We also manufacture specialist equipment like sludge dewatering belt presses, and Archimedean screw pumps. Significantly, our local reference installations exceed 25 years or more,” Van der Walt continues.

Turnkey approach LWT develops turnkey solutions that provide peace of mind, collaborating with subcontractors like civil, process and electrical engineers, to execute projects.

The company’s in-house team comprises mechanical engineers, designers, draftsmen, project managers, fabrication specialists, expert artisans and installation teams. “This in-house component always gives you one point of contact and reference. We boast a combined experience of more than 215 years and this fact is mirrored in our 550 reference plants,” says Van der Walt.

LWT complements its manufactured products with the latest cutting-edge technology, like pumps and gearboxes, from leading OEMs. Equipment is supplied according to client preference or to meet standardisation requirements. The company is also an agent for international technology suppliers like Aerostrip (diffusers) and Giotto (belt presses).

LWT has completed work on 550 reference plants in the water and wastewater fields

Value engineering There are various scenarios and stages in a project where LWT can add value: • The first and ideal situation would be when involved from the conceptual and planning phase through to design, manufacturing and implementation.

• Second, LWT executes contracts emanating from tenders and quotations.

• Third, LWT can take over specific functions, on client request, where there is a lack of depth in terms of the competencies and capabilities of other contractors, consultants or suppliers.

• Lastly, the company prides itself on taking a completely rundown facility and transforming it into a high-tech, working treatment plant.

During its 32 years in existence, LWT has supplied equipment to water and wastewater treatment plants across South Africa. These installations include various plants operated by the City of Cape Town (CoCT).

“Many of the items are still in operation some 10 to 15 years after installation due to the excellent management and maintenance the CoCT performs on its plants, as well as the fact that our high-efficiency equipment requires less operation time and maintenance,” Van der Walt concludes.

www.lwt.co.za

For the design and fabrication of a comprehensive range of water and effluent treatment equipment for municipal and industrial applications.

CIT Y OF CAPE TOWN

Making sludge sustainable

The City of Cape Town will soon begin construction on the first of three planned centralised biosolids beneficiation facilities.

By Danielle Petterson

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s a measure to establish a more sustainable sludge management chain, the City of Cape Town plans to build regionalised anaerobic digesters to treat its sludge and harness economies of scale at both capital and operational levels.

The use of activated sludge treatment processes for wastewater can result in large quantities of excess primar y and/or waste activated sludge – the treatment and disposal of which presents a growing challenge, in terms of both treatment and disposal cost, and environmental legislation.

The benefit of anaerobic digestion (AD) is its simplicity, its relatively low-cost operation, and its ability to produce biogas, which allows for heat and energy production.

Electricity is one of the highest-cost items on the operational budgets of energyintensive activated sludge wastewater treatment works (WWTWs). However, when operated correctly, AD enables WWTWs to produce their own electricity and heat.

Cape Town’s strategy is to implement thermal hydrolysis in order to hydrolyse the sludge upstream of the AD to improve its digestibility, and to achieve a pasteurised treated sludge product, which will allow for the digested sludge to be used beneficially for a larger number of end uses. The biogas produced from the high-rate anaerobic digesters will be used to generate steam for the thermal hydrolysis process, while the balance of the biogas will be used to fuel combined heat and power, which will produce heat and electricity for on-site use.

The use of AD will also support new national solid waste legislation that seeks to divert organic material from landfill. Currently, the City of Cape Town disposes of its dewatered primar y sludge at a hazardous landfill located within the city’s bounds.

Dewatered waste activated (secondar y) sludge is currently applied to certain farmland – agricultural land that is used to grow animal feed. However, available agricultural land is running out, and an alternative solution for the disposal of

both primar y and waste activated sludge is needed.

Current capabilities Cape Town is in a unique situation when it comes to anaerobic digestion. The city has 25 wastewater treatment facilities, of which 15 are activated sludge wastewater treatment facilities. The majority of these 15 facilities were originally designed as extended aeration plants, without primar y sedimentation and with long sludge age bioreactors. As a result, only five of the

IMIESA May 2020

27

Superior media, superior filtration

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facilities had anaerobic digesters originally. Of the five, three digester installations are ambient temperature, unmixed digester facilities from when the treatment plants consisted of only trickling filters. Two installations are heated and mixed.

Currently, one heated (35°C to 38°C) and mixed digester complex and one ambient temperature and unmixed digester complex are in use, while the other three were decommissioned years ago for various reasons.

The city recognised the need for a new and sustainable sludge treatment and disposal approach and, after several years of planning, Cape Town’s Wastewater Branch has received approval for the establishment of two centralised biosolids beneficiation facilities (BBFs), with the aim to establish a third facility in the future.

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The planned BBFs will cater for Cape Town’s future sludge handling, treatment and disposal needs. The facilities will incorporate imported sludge cake offloading and storage facilities, thermal hydrolysis sludge pre-treatment, high-rate anaerobic digestion, digested sludge dewatering, sludge liquor treatment, and combined heat and power processes.

Funding for the first facility has been approved, and the design and construction tender documents for the Southern BBF are complete. The project is scheduled to go out to tender for construction this year and the facility is expected to be completed by 2023/24 The Southern BBF, located at the Cape Flats Wastewater Treatment Works, will be constructed on a brownfield site, making use of the three existing 6 000 m3 anaerobic digesters.

The generated electricity will be able to supply approximately 70% of the host WWTW’s current electricity needs, thereby offsetting some of the costs of the facility. The final destination of the beneficiated sludge is still being decided, and the city is researching available options.

The second BBF installation will kick off in the near future, and together with the Southern BBF will provide sufficient capacity for the city’s medium-term sludge production. The third installation will be built over the longer term, as and when more capacity is required.

The city is currently not sizing the BBFs to accept waste from surrounding industries, as the capacity is needed to accommodate Cape Town’s current wastewater sludge streams.

Each centralised BBF will receive dewatered sludge cake from approximately five to six surrounding ‘donor’ WWTWs. The regionalised facilities are being designed to accommodate the ultimate sludge production capacities of the surrounding WWTWs and have been positioned to minimise travelling distance from the donor plants.

However, the future third BBF facility may have spare capacity, in which case the city will explore the option of accepting additional sludge or clean organic waste from industr y and adjoining municipalities for digestion.

In terms of sustainability and sludge disposal, the City of Cape Town Wastewater Branch is of the belief this project will be a big leap for ward. The current sludge disposal methods are no longer considered sustainable and this new step for ward in sludge management will contribute to the municipality’s plans for making Cape Town a more sustainable city. .

CIT Y OF CAPE TOWN

Virgin plate glass media revolutionises filtration Not all glass media is equal

The water usage, energy and chemical cost savings achieved by virgin plate glass media far surpass silica sand alternatives in a broad range of filtration systems.

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ver the past 24 years, Ultra Water has refined its leadership position, pioneering the development and application of OEM filtration technologies aimed at improving industrial and municipal water and wastewater process efficiencies. Operating from its Cape Town head office, the company provides expert advice and custom plant optimisation solutions, alongside the bulk supply of chemicals.

Services include the building and installation of pressure filters, reconditioning filters (pressure and gravity), specially graded filter media, and filter parts. Certifications include ISO 9001:2015 (Quality Management System), ISO 14001:2015 (Environmental Management System) and

Glass media filtration uses 50% less water compared to sand.”

OHSAS 18001:2007 (Occupational Health and Safety Management System).

Some 48 months ago, the company’s Ultra Clear division achieved a major R&D breakthrough with the launch of its glass media range. What makes Ultra Clear’s media unique is that it is sourced from plate glass off-cuts. Unlike recycled glass, their specific plate glass contains a perfect balance of metal oxides. The latter improve the durability, shock and temperature resistance of the product.

“We’ve developed a glass crushing and screening plant that can produce speciality graded filter media for all envelopes,” explains Jaco de Villiers, sales and marketing manager, Ultra Clear. “When it comes to grading, particle shape is vitally important for uniform filtration. For this reason, we use a horizontal impact crushing methodology to achieve the desired subangular and highly spherical shape.

“This greatly increases the contact time and area, virtually eliminating the channelling effect often caused by sand filter media due to inconsistent grain sizes and packing.

Using glass filter media results in far more effective use of the entire filter bed,” he continues.

“Our glass media also removes aluminium from treated water and improves its turbidity,” says CW Pretorius, CEO Ultra Water, adding that this was demonstrated during a project at Langeberg Municipality. Langeberg’s existing sand filter media was proving ineffective in these areas.

“Langeberg invited us to investigated the issue on site. We proposed the use of glass filter media. After replacing their sand filter media with Ultra Clear the problem was solved,” Pretorius continues.

Being sourced from plate glass, Ultra Clear’s media is durable and rigid. This means it doesn’t splinter off during the backwash and normal filter cycle.

Ultra Clear products are offered in three specifications, namely Grade 0 (0.425 mm to 0.597 mm), Grade 1 (0.597 mm to 1.4 mm) and Grade 2 (1.4 mm to 2 mm).

Key benefits of Ultra Clear Research backed by field studies has shown that Ultra Clear products have a replacement cycle of 15 to 20 years, while silica sand should be replaced every three years.

Additionally, Ultra Clear filters to 5 microns, compared with 15 to 20 microns for silica sand.

“A small percentage of free radicals (O- and HO-) are present on the surface of each Ultra Clear glass particle. It’s part of the chemical composition of the glass that we use,” says De Villiers.

These free radicals exhibit a strong oxidation potential, which protects the media from bacterial growth. It also displays a negative charge that attracts organic matter and metals, which are released during the backwash process.

Compared to sand, glass media saves 50% of the backwash water that is wasted, passing on significant water and electricity savings.

With glass media, backwash intervals can also be extended compared to silica sand, which translates into longer and more efficient filter runs.

“We’re excited about the growing potential for Ultra Clear media as municipalities, utilities and industry recognise the proven cost benefits and marked improvement in water quality,” De Villiers concludes.

IMIESA May 2020

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CITY OF CAPE TOWN

Zandvliet’s mega expansion showcases excellence The City of Cape Town’s R1.8 billion investment at Zandvliet Wastewater Treatment Works (WWTW) will increase current capacity from around 72 to 90 million litres per day. Main contractor Stefanutti Stocks Coastal expands on the project complexities of seamlessly interconnecting the old and new plants.

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erving one of Cape Town’s fastest growing catchment areas, the completion of the Zandvliet WWTW expansion will cater for around 150 000 additional people using stateof-the-art technology to optimise process efficiencies. In the meantime, the existing WWTW continues to serve its catchment, which covers the south of Kuils River, Delft, Blackheath, Eerste River and the township of Khayelitsha plus surrounds.

The 18 Mℓ Zandvliet WWTW expansion extends over an 18 ha footprint and provides for a new enlarged inlet works, two new screw pump stations, four new primary settling tanks, a primary sludge pump station, a sludge dewatering building, sundry holding tanks (two primary sludge and two WAS), An aerial perspective taken in May 2020: to the left of the central roadway is the sludge dewatering building forming part of Portion A. To the right of the roadway are the four primary settling tanks forming part of Portion B

pipelines, access roads, and minor services like site drainage.

Once the plant goes live, around 60 tonnes of dewatered sludge will need to be removed from the facility daily.

Community consultation From the onset, Stefanutti Stocks engaged with the community. Initially, this involved ward 109 bordering the site, but was extended to include the adjacent wards 95 and 96. A community liaison officer was appointed for each ward. The fact that the project includes a sizeable building component presented oppor tunities for the employment of skilled trades.

Since mobilising on-site in November 2018, Stefanutti Stocks has forged ahead on this multifaceted construction programme, harnessing its extensive experience built up over the past decade in the water and wastewater treatment sector. In addition to Zandvliet, Stefanutti Stocks is also working on numerous other water cluster projects

PROJECT DATA Concrete

13 500 m³

Reinforcing

1 440 t

Formwork

35 783 m²

Excavation

259 880 m³

Backfill

180 000 m³

Pipe laying

4 973 m

nationally, located in Gauteng, KwaZulu-Natal and the Western Cape.

Parallel programme The Zandvliet expansion is divided into three portions, namely A, B and C. Portion A was originally due for completion in March 2020 but moved out slightly to May due to the national Covid-19 lockdown; Portion B was scheduled for completion in November 2020 (and now shifts to December); while Portion C is on track for completion in October 2022.

Elements in A and B have run in parallel, forming the critical path, with C incorporating the final electromechanical installation, testing and commissioning phase. Towards the end of Portion C (March 2022), Stefanutti Stocks will return to site to complete the demolition of the old treatment building structures and connect the existing and new plants. For this purpose, a large concrete culvert was built flush with the wall of the existing adjacent inlet works to act as a future conduit.

ZANDVLIET WWTW PROJECT Location Khayelitsha Client City of Cape Town Consulting engineer Aurecon Contractor Stefanutti Stocks Construction contract value Approximately R325 million Total project value (including mechanical and electrical) R1.8 billion

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IMIESA May 2020

CIT Y OF CAPE TOWN

Construction of the Lower Screw Pump Station now above the water table

“During the final go-live stage in Portion C, we will core-drill through the approximately 1.5 m thick existing inlet wall to allow for raw sewage to flow into the new works,” explains Tim Milner, project manager, Stefanutti Stocks Coastal.

Key works of Portion A included the sludge dewatering building and allied facilities.

Meanwhile, segments of Portion B entailed the four primary settling tanks and the new inlet works. The latter required deep excavations to an approximate depth of 10 m deep (6.7 m below the water table), which necessitated the use of staged construction methods and dewatering.

“Establishing the myriad interconnecting pipework between the old and new plants also proved particularly challenging,” says Milner. These pipelines are a mixture of GRP, concrete and HDPE.

Concrete elements As is standard practice for a treatment works, the concrete mixes have been formulated with a high water-to-cement ratio to ensure the watertight integrity of the structures. Additionally, a specialist 2.5 mm thick anchor knob sheet (AKS) lining system was installed on selected structures to counter chemical attack and corrosion.

1,4 m diameter GRP and 900 mm diameter concrete pipes needed to be carefully installed between existing infrastructure

“These installations required exper t attention and specialised formwork methods, as these HDPE liners are applied as a monolithic ‘cast in’ sheet during the wall pours,” Milner continues, adding that approximately 6 000 m² of AKS was installed. AKS liners are manufactured with 1 230 anchors per square metre, ensuring a firm interlock.

The largest single structure formed was a raft slab, which required more than 600 m3 of concrete. The original plan called for skip placement in conjunction with three cranes – an intensive process that would have taken around 48 hours to complete. Stefanutti Stocks motivated for an alternative approach, which was accepted by the consulting engineer.

A 28 mm blended pump mix was formulated, with placement completed in approximately 12 hours. The original approach specified a 38 mm batch mix. In addition to time and cost savings, going the pumped route also greatly enhanced health and safety.

Forward order book As work progresses at Zandvliet, Stefanutti Stocks continues to secure new work in the niche water and wastewater segment. A

The 660 m3 raft foundation for the Lower Screw Pump Station was cast 7 m below the water table. This required two levels of dewatering to ensure the base remained dry

recent example is the Coega Kop wellfield project for Nelson Mandela Bay Municipality (NMBM). Stefanutti Stocks has been appointed for the construction of a new 20 Mℓ/day treatment plant in consortium with Paterson Candy International as the mechanical partner. The contract is due to commence in June 2020.

“The Coega Kop wellfield project will supplement NMBM's existing potable water supplies. Borehole water extracted from these wellfields will be purified, removing dissolved iron and manganese concentrations via biofiltration technology,” explains John Woodburn, contract director, Stefanutti Stocks Coastal.

Back in Cape Town, Stefanutti Stocks has also received a conditional award for the Cape Flats Managed Aquifer Recharge Project. This will entail the construction of a new advanced oxidation tersary treatment plant at the existing Cape Flats WWTW. The new plant will purify the treated effluent produced to SANS 241 standards before it is injected into the Cape Flats aquifer.

“Aside from changing the way we live and work, Covid-19 has placed even greater emphasis on the need to maintain, upgrade and construct new water and wastewater facilities. This is a core area of expertise for Stefanutti Stocks and we look forward to engaging with municipalities to clear backlogs and ensure sustained water and sanitation nationally,” Woodburn concludes.

www.stefanuttistocks.com

CITY OF CAPE TOWN

Energy efficiency will play a key role in reducing emissions and mitigating the impact of rising electricity tariffs on the City of Cape Town.

Credit: Bruce Sutherland

Pursuing carbon neutrality

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ommitted to achieving the goals of the Paris Climate Agreement, the City of Cape Town is currently in the process of developing a Carbon Neutral 2050 Goal and a Climate Action Plan, scheduled to be finalised by the end of 2020.

Building on the city’s existing Energy2040 goal, a detailed greenhouse gas inventory and modelling projections have identified the big-ticket mitigation actions in the local context. Several projects are already under way to support the city’s ambitious carbon neutrality goals.

“The city is a staunch proponent of more affordable, secure, cleaner and diversified energy sources. The ultimate goal is to move away from Eskom being the sole supplier of energy and the city has been fighting for this diversification for years.

“Another key focus is bringing greater equality in the electricity regime and, to this end, the city continues work on its low-income energy programmes,” says Cllr Phindile Maxiti, MMC for Energy and Climate Change, City of Cape Town.

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IMIESA May 2020

Small-scale embedded generation The Small-Scale Energy Generation (SSEG) programme promotes the uptake of rooftop photovoltaic (PV) systems and small wind turbines in the commercial and residential sectors. It allows customers to export a limited amount of energy on to the city’s grid, for which they are credited.

In the absence of national legislation, the city developed its own suitable SSEG tariffs, bidirectional metering systems and automated billing systems that allow the purchase and sale of electricity. “These are now being incorporated into the drafting of national legislation and strongly promote transparent processes,” explains Maxiti.

There are currently over 600 residential and 200 commercial and industrial grid-tied PV systems, with an embedded generation capacity of over 32 MVA.

Energy efficiency Residential and commercial buildings in Cape Town are responsible for approximately 37% of energy consumption and account for approximately 58% of carbon emissions, due

to the poor energy efficiency and high carbon intensity of electricity production.

“It is important that buildings are designed and constructed to be highly energy efficient, as this reduces the need for expensive retrofitting in the future and will massively reduce resource use burdens,” says Maxiti.

To address this, the city is a signatory to the Net Zero Carbon Buildings declaration, which commits it to net-zero carbon for all new buildings and all municipal buildings by 2030 – and for all existing buildings by 2050.

The city is coordinating a successful Building Energy Efficiency Retrofit Programme. To date, 44 large municipal facilities have been retrofitted. Four buildings underwent full energy-efficiency retrofits, 16 facilities were retrofitted with energy-efficient fluorescent lighting and occupation sensors, and 24 facilities have been retrofitted with LED lighting and occupation sensors.

From 2009 to 2019, the programme saved more than 169 505 MWh, which translates to a financial saving of R190 million and a carbon saving of 167 810 tCO2e The city has also retrofitted more than 1 200 km of its streetlights with LEDs, resulting in an energy saving of about 40%.

All the city’s traffic lights have also been retrofitted with LEDs. According to Maxiti, these efforts send a bright message that we must all work smarter and use technology to unlock the future we want.

“This is even more important as the country, like the rest of the world, grapples with the Covid-19 pandemic. The additional challenges of energy security in South Africa are a real consideration, especially during this time of crisis. We must do all we can to prepare, plan and reduce the stress on the system going into the winter months.”

INFRASTRUCTURE FUNDING

Desalination going mainstream – but are we ready?

Alternative water resources, such as desalination, are going to become much more prominent in the next 10 years, according to current national water planning models, with a major focus on the municipal space. By Dawid Bosman*

W

hen the National Water and Sanitation Master Plan (NW&SMP) was launched in November 2019, it was clear from the outset that a positive water balance could not be sustained by merely building more surface water infrastructure. The NW&SMP calls for action along the entire water value chain, and for both supply and demandside aspects of water management to be addressed.

South African households will need to learn how to consume less water, and municipalities will need to minimise wastage. For this to be achieved, institutional capacity at the municipal level will need to be raised to enable effective programmes for pipe replacement, pressure management technology, smart grids, demand management and improved revenue management.

But, significantly, the NW&SMP also calls for alternative water resources – such as desalination, reuse and groundwater – to be developed on an unprecedented scale.

Especially in the metros and large towns, we need to reduce our reliance on surface water, partly because of a drying climate, and partly because of fewer viable options

remaining for new dams. There is pressure to diversify the water resource portfolio.

It is the share allocated in the NW&SMP for desalination that I find particularly interesting. The desalination of sea water, and mine water to a lesser degree, is foreseen to grow quite dramatically. Our current inventory is made up of some 15 very small plants, mostly in the capacity range of 1 Mℓ/day to 2 Mℓ/day (megalitres per day), and only three plants in the 10 Mℓ/day to 50 Mℓ/day. Most of these plants were hastily constructed during times of drought, and suffered some technical difficulties, be it intake problems or poor metallurgical choices.

In total, there is an installed capacity of about 104 Mℓ/day, counting both seawater and acid mine drainage plants.

The NW&SMP proposes that this should grow to about 1 600 Mℓ/day in 10 years, which is a fifteen-fold increase. We need to prepare for this.

Cost projections Using the DesalData benchmark for EPC cost of US$1 400 per kℓ/day capacity, and at R18 to the dollar, this indicates an outlay on desalination plants equal to R41 billion within 10 years, spread over perhaps 10

to 15 projects. As I see it, the capital for this will be obtained either off-budget or as developer-funded.

This will have quite a few implications.

First, we are not seeing this scale of desalination in the current plans and strategies of the coastal towns and metros – so, there will be a need to bring alignment between the different planning platforms.

Then, there is the matter of implementing capacity. The acquisition and operation of desalination assets are fundamentally different to conventional water resource assets in almost every way, across the entire life cycle of the asset.

Today, even the most capable of our metros will be hard pressed to go to the market for either a design-build tender or a price auction on an XL-class desalination plant. This could largely be remedied with greater certainty of strategy and policy, clean governance, and the focused application of resources. South Africa needs to build a capacity for climateindependent water, but there is much work to be done. *Dawid Bosman is a senior manager: Strategic Advisory at the Trans-Caledon Tunnel Authority (TCTA).

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INFRASTRUCTURE FUNDING

Blended finance and bankable projects Finding the middle ground within a conducive political framework will be essential in rebuilding and accelerating South Africa’s infrastructure economy post the Covid-19 crisis. It star ts with a credible project pipeline and a zerotolerance approach to corruption. By Alastair Currie

Dr Sean Phillips, Development Bank of Southern Africa

T

he impact of the novel coronavirus pandemic will be far reaching, but one aspect that it has immediately highlighted is the pressing need to address shortfalls in social infrastructure, particularly formal housing, water and sanitation. Another is the essential need to engage the private sector in government policy decisions when it comes to the macroeconomic environment.

It is government’s responsibility to make

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IMIESA May 2020

investment conditions attractive for foreign and local investors, and that depends on policy certainty and equal opportunity.

One of the potential catalysts is South Africa’s Infrastructure Fund (IF), housed at the Development Bank of Southern Africa (DBSA). Announced by government in 2018 as part of an integrated stimulus package, the construction and allied investment market has been awaiting its roll-out with keen interest.

The IF is geared towards executing and fast-tracking the National Development Plan 2030 and allied strategies, while addressing historical stumbling blocks that have impeded roll-outs and led to unnecessar y wastage. Effective project preparation and more coherent regulatory and procurement frameworks are critical to the success of the IF, as is strict oversight

by National Treasury. It is also proposed that the IF must be backed by a dedicated implementation unit and that funds raised and expended on projects are ring-fenced.

While government has scaled back on infrastructure budget allocations in recent years, the availability of funding year-on-year has still been substantial, but most of it hasn’t been expended as planned. The main issue, aside from misappropriation, has been a concerning trend of underspending by municipalities, chiefly due to capacity constraints. Bringing the private sector on board as an infrastructure implementation partner would therefore make a positive difference, given the right incentives.

“We are in the interesting situation in South Africa where there’s no shortage of funds in the private sector to invest in public infrastructure,” says Dr Sean Phillips, manager, Infrastructure Fund, speaking recently at the 2020 CESA Infrastructure Indaba. “The real challenge is the absence of sufficient bankable projects that can be brought to the market.”

INFRASTRUCTURE FUNDING

Preference is given to projects with high leveraging of private or non-government investment and which do not require government guarantees.”

The DBSA’s Infrastructure Delivery Agent has a solid track record in supporting government, with approximately R15.2 billion worth of infrastructure completed between 2013 and 2019. Over this period, that equates to 4 618 practical completed projects, including 304 municipal projects.

Cash injection Government committed to making R100 billion available to the IF over 10 years to address viability gaps and to leverage much higher levels of private sector investment via blended finance models. This could come in the form of government capital grants for specific projects, plus risk mitigation suppor t via development finance institutions for specific projects that may be less attractive for the private sector.

Commercial projects with strong revenue generation expectation, like toll roads, would be expected to have a relatively smaller government contribution. In all cases, however, suitable projects need to be of a large enough scale to justify the cost of feasibility studies.

“However, it’s not just about attracting funding – it’s equally about har vesting private sector skills and capacity for planning, construction, operations and maintenance, which is greatly needed in some public entities, particularly for municipal infrastructure,” Phillips continues.

The DBSA is currently identifying suitable blended finance projects that can be submitted to National Treasur y for vetting, subsequent approval and budget allocation to specific government depar tments or

special-purpose vehicles. Forming part of this process, National Treasury has made around R400 million in project preparation funding available to the DBSA. Additionally, the DBSA is engaging with private sector associations regarding the development of potential financial instruments to channel investment funds into IF projects.

Preparation and implementation The DBSA continues to build its project pipeline and is open to suggestions from the public and private sectors, including the banking sector. Currently, there are two IF projects in the implementation phase, namely the Student Housing Programme and the Social Housing Programme. The DBSA plans to expand both programmes and develop a series of alternative implementation models, which include higher gearing in terms of private sector funding.

Gautrain Phase II is at an advanced stage of project preparation although it has not yet received Tier 1 approval from National Treasury. Other initiatives at the project preparation phase include the One-Stop Border Post programme, which has been registered as a public-private partnership (PPP), and the rural broadband programme.

The DBSA also sees significant potential for private sector investment in South Africa’s municipal water and sanitation sector. Initiatives include the outsourcing of operations and maintenance on water and wastewater treatment plants, desalination and non-revenue water programmes.

The DBSA has also received proposals for embedded generation at public facilities.

Gauteng is at an advanced stage with a PPP for embedded generation in schools and hospitals.

Improving regulatory frameworks There are some legislative and regulatory impediments that need to be overcome, with the DBSA engaging with National Treasury to improve current processes.

These include the present PPP regulatory framework. Mirroring the Renewable Energy Independent Power Producer Procurement model sets a good benchmark.

National Treasury’s PPP Unit currently waits for government bodies to submit proposals. The outcome so far has been disappointing and to date only about 2% of public infrastructure is privately financed.

“We believe that the PPP regulator y framework needs to be changed to enable nationally driven programmes like water and sanitation,” says Phillips. “Ideally, we need a process where all approved infrastructure projects are evaluated for potential private funding.”

Given the severe economic impact of the coronavirus locally and globally, the IF is an essential element in boosting investment appetite and gross fixed capital formation. Infrastructure funding from South Africa’s fiscus is going to be even more constrained as government revises its national 2020/21 budget downwards and diverts funds to manage Covid-19 impacts, with a major emphasis on welfare and unemployment grants. Health will also be an obvious priority.

The fact that South Africa’s business confidence levels were at a low point prior to the pandemic now makes publicprivate cooperation even more important in lifting the country out of a deep economic dip. Ending corruption, removing the red tape, and spending more efficiently on infrastructure and its maintenance is essential. It starts with bankable projects and implementation.

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35

IT & SOFT WARE

The BIM revolution As South African companies move to embrace the Four th Industrial Revolution, there is a greater move for built environment professionals to adopt building information modelling (BIM). By Danielle Petterson

A

lthough definitions for BIM var y, it is widely accepted as an intelligent, agreed-upon collaboration process that commonly ends with a 3D design linked to a database. BIM is essentially the same as 2D documentation (drawings, specifications, etc.) but easier to visualise. This gives architects, engineers and construction professionals the insight and tools to more efficiently plan, design, construct and manage buildings and infrastructure.

The technology has proven to be effective across the entire project life cycle – by creating a virtual model that extends 3D design with the ability to add a time dimension (4D), a cost dimension (5D), and a facilities management dimension (6D). BIM collaboration is a key component in the life cycle of design, execution and operation – one that greatly enhances the value each element brings to the client.

While BIM has been around for some time, South Africa has been slow to adopt the technology. According to Vaughan Harris, executive director, BIM Institute, South Africa is on par with many developed nations when it comes to technology and professional expertise. However, a lack of national guidelines or best practice standards and protocols may be holding us back.

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IMIESA May 2020

An industry revolution BIM offers many benefits to the built environment, including increased productivity, time-saving, enhanced designs, and the increasing use of artificial intelligence tools. In fact, BIM is becoming widely accepted as an essential tool for built environment professionals due to its ability to improve a construction team’s efficacy.

BIM also contributes to the development of smart buildings and, by extension, smart cities.

According to Harris, BIM has become one of the biggest changes the industr y has ever seen and holds the potential to bring about an industr ychanging revolution for information and communications technology and cultural processes for the construction and smart buildings industr y.

However, implementing both BIM software and its processes comes with a learning cur ve and a series of local challenges that need to be overcome.

Adoption challenges Although the private BIM client base in South Africa is expected to grow, many asset managers are still hesitant to adopt new technologies, preferring to rely on traditional methods of asset management.

Moreover, it takes more time, effort, detail and data to compile the 3D

model at the beginning of the process compared to traditional methods.

However, Harris points out that this will pay off significantly further down the line as a building assembly model and finally as a building operation optimisation model for owners or operators to manage their infrastructure.

Added to this, BIM brings all parties involved in the project together to share information and data through a common data environment. This requires overcoming the mentality of working in silos.

“Implementing BIM in an organisation is so much more than loading the right software on to the right devices. It’s about educating an entire workforce about digital tools, processes and workflows to meet stringent standards.

That’s a big challenge,” says Harris.

And that challenge grows as software and process adoption needs to be driven across geographically diverse teams with varied levels of experience, workloads, motivation, access to technology and learning styles.

“Organisations are facing a knowledge gap that prevents them from achieving development trends and all too often the focus is placed on IoT (internet of things) instead of first focusing on IoC (internet of construction). All too often, companies who do not yet understand the role of BIM within a day-

IT & SOFT WARE

to-day operational environment seem to think it’s all about design and deliver y,” adds Harris.

Proper training is therefore crucial to driving BIM implementation, and Harris believes that all levels of staff – from high-level management to non-technical support staff – must be engaged, fully understand why the organisation is making the transition to BIM, and be prepared for some difficulties they are likely to experience in the early stages.

across the public ser vice on the basis of a high-level strategy.

It is envisaged that a BIM mandate will have a twofold purpose, namely: (1) to ensure that public bodies invest the necessar y resources to adopt BIM in line with the strategy; and (2) to

Government backing Harris believes that a South African national BIM guideline is needed to assist in the adoption of the technology. This should be established first based on a lessonslearned approach, after which standards can be adopted based on global best practice, namely ISO 19650. Many countries – including the UK, Singapore and Australia – have done a lot of work in this regard in response to their government policies, and this is readily transferrable to the South African construction industr y.

The South African government holds huge potential in promoting BIM through standards, pilot projects and support.

Harris explains that government should note the benefits that BIM can bring to the public capital programme and the challenges associated with it, as well as decide to mandate the adoption of BIM

impose standards for deliver y across the public sector.

“An oversight body will need be established, which will comprise officials with expert knowledge of the technology but also those with extensive design management, cost management and procurement experience. The body can be chaired by the BIM Institute and will make recommendations to the CIDB on the manner in which BIM should be procured and the standards to which the BIM model should adhere, until an EN/ ISO standard covering BIM is adopted,” Harris continues.

BIM can further be driven by South Africa’s large construction firms. If they were to unite in support of the BIM initiative, their knowledge and cumulative market power could drive BIM standardisation in South Africa.

However, Harris believes that a piecemeal approach to adoption across the public sector will result in a lack of consistency from procurement and contract perspectives.

Financial and technical resources will be wasted, as public bodies each develop their own approach, and greater investment will be required to undo the nonstandard practices.

Currently, organisations can access the BIM Institute’s National BIM Guide, which is based on the international best practice BIM Framework.

All information and links provided are through the guidance development philosophy of Australian Natspec, AEC (UK) BIM Standards, and the Canadian BIM Council (CANBIM).

Despite the lack of national guidelines, Harris believes BIM holds huge potential for South Africa. “We are changing the world with technology, but the world is also changing the demand for technology. Within the building design and construction industr y world, the demand for technological changes is becoming greater and greater, and there is a substantial gap between design deliver y and operation.”

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37

WATER & WASTEWATER

Increased electronics usage poses risks Electronics have become prevalent in all but the simplest of processes in water and wastewater projects.

However, increasing electronic control and automation comes with risks that engineers must be aware of and able to identify.

By Peter Fischer*

W

ater and wastewater projects increasingly utilise electronics to control a growing multitude of functions – from optimising processes to providing additional safety features and improving the lifespan of plant and equipment.

There is no doubt that electronic control and instrumentation provides many new opportunities and positive advantages for water and wastewater infrastructure.

However, it has brought with it many less obvious challenges, and the risks are often overlooked.

Risks specific to electronics The risks that affect electrical and electronic systems include lightning strikes, power outages and surges, incorrectly installed cables near medium- or high-voltage cables, a lack of operator competence, hydrogen sulfide emissions in wastewater systems and, in some instances, commissioning not being properly executed and documented.

The exposed parts of electronic connections and junctions operate at low voltages (<24 V) and typically carry low currents of 4 mA to 20 mA. The cross sectional areas of copper wires for electronic components can be very small, where single-core wires are 0.32 mm in diameter or smaller. Copper tracks on PC

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IMIESA May 2020

board slots are very thin, typically in the order of 35 μm.

Open circuits can occur in a matter of weeks due to the corrosive effect of fugitive gases such as hydrogen sulfide (H2S) and chlorine on thin copper wires or PC board tracks and contacts, so the effects of copper corrosion can be devastating.

Silver-coated wires and components are equally prone to the corrosive effects of H2S, as they can form dendrites that grow like microscopic trees and can cause short circuits between adjacent electrical pathways.

Electrical and electronic installations are subject to many other risks, but none are as subtle nor as devastating as the effects of gaseous and airborne chemicals.

If the operating environment has not been designed or managed properly, the costs for electronic replacement parts, highly skilled labour and operational downtime can affect the very viability of the infrastructure.

Approaches to reduce risk Failures are seldom due to a single cause.

The following recommendations should always be considered in the conceptual and preliminary design stages of water and wastewater infrastructure projects where electrical and electronic control components are to be installed.

1. Prevent water, sewage or process chemicals making direct contact with components - Locate the MCC and the PLC enclosures well away from any high-pressure pipework or pumping components where a leak can spray water or chemicals directly on to the MCC or PLC. - Free water from the condenser coils of air conditioners must be captured in enclosed drip trays, and provided with adequately sized pipes so that free water can never drip or be blown on to electrical and electronic components.

2. Prevent harmful gases from making contact with the electronic components - The corrosive effects of gases such as H2S are devastating when they meet copper and silver components in electronic equipment.

- This source of damage is not always obvious because the corrosive effects are not generally understood or appreciated.

3. Reduce H2S emissions - H2S and other harmful gases are released by orders of magnitude higher under highly turbulent conditions when energy is released at sharp bends, hydraulic jumps and cascades, as compared to when the flow regime is laminar or when the water surface is not broken.

- Cascading or plunging sewage and hydraulic jumps must be avoided.

- Incoming sewer velocities at pump stations and sewage treatment works should be minimised by designing the incoming sewers with flat grades, appropriately large diameters and sufficiently long approach lengths.

4. Scrub off gases to reduce fugitive gas concentrations - Several types of scrubbers are available, all with their own advantages and disadvantages.

- Scrubbing is often used primarily for odour control. The protection of electronic equipment from fugitive gases can be considered in conjunction with odour control systems, but it requires careful ventilation design as well as other mitigating systems to effectively protect electronic equipment.

5. Position the PLC and MCC to avoid fugitive gases - The PLC and MCC should always be positioned as far away from the discharge point of the fugitive gases as possible, and upwind relative to the prevailing wind direction.

- MCC and PLC rooms must not have any openings where fugitive gases can pass into the MCC or PLC enclosures directly, such as through cable openings or ventilation ducts.

6. Proper design of ventilation systems - Separate ventilation systems should be used for the provision of: • general fresh air for areas such as pump rooms and screening chambers • clean/scrubbed air for the PLC and MCC enclosures.

- If general fresh air and clean/scrubbed

WATER & WASTEWATER

air systems are to be combined, then special attention must be paid to air flows and pressure balances so that fugitive gases cannot come into contact with electronic control equipment under all operating and fault conditions, such as normally closed doors or openings being left open, or strong external winds/storms coming from directions that were not taken into account in the ventilation designs.

7. Provide clean air for PLC and MCC enclosures - The PLC and MCC enclosures should use forced ventilation so that the rooms are under positive pressure at all times.

- The air should be filtered and scrubbed to specified levels of purity in terms of fugitive gases and particles, such that there will be no long-term build-up of contaminants that can cause harm to the electronic components.

- ISO 14644-1 can be used to classify and specify the requirements for clean rooms.

- Temperature and humidity must be kept relatively constant.

- Double door systems with air locks should be provided.

- An alarm with corresponding automatic notifications should be sent to operations and management staff for urgent interventions.

8. Hard-wiring of components - Hard-wiring, which essentially comprises dedicated control wires from the MCC (not PLC) to primary items of plant, has been specified by experienced and conservative engineers since the advent of PLCs. - Hard-wiring allows operators to run the plant when the electronic functions of the PLC have failed.

- Hard wires can be used during cold and dry commissioning to test that physical connections between the MCC and the components are working, especially if there are teething problems with the PLC. - Less-experienced electronic engineers are prone to regard this requirement as ‘old school’ and to argue for not including it in their technical requirements but lead design engineers should insist that this is done. The relatively low cost and many advantages of hard-wiring cannot be overemphasised.

Recommendations Although some of these approaches may seem extreme, if they are considered early enough in the design and detailing stages, they do not necessarily add inordinate costs. Net savings will almost always be achieved when life-cycle costs are considered.

The success and operability of otherwise well-designed water and wastewater infrastructure can be ruined if the electronic equipment is not reliable due to one or more shortcomings in the design and/or detailing of a project.

Design engineers therefore need to be aware of the vulnerability of electronic components and incorporate protective features from the beginning of the conceptual design stage to provide optimal protection, functionality and operability of the electronic components in municipal water and wastewater infrastructure.

FIGURE 1 Example of a common microclimate: Cracks between plastic remainders and copper pins in combination with a low amount of H2S and relative humidity >60% that led to creeping corrosion

FIGURE 2 Products of dry corrosion emerging from gaps and plated through-holes

FIGURE 3 Silver sulfide (AgS) needle-shaped crystals, providing evidence of a ‘short circuit’ failure FIGURE 4 Cross section of a corroded copper track after mixed gas test (H2S (2.11 ppm) + SO2 (10 ppm) + Cl2 (0.1 ppm), 21 days) showing the build-up of corrosion

FIGURE 5 Dry copper sulfide crystals emerging from a plated through-hole; no dendrite, no creeping

Images reference: G Vogel, Creeping corrosion of copper on printed circuit board assemblies, Microelectronics Reliability (2016), http://dx.doi.org/10.1016/j.microrel.2016.07.043 *Peter Fischer is a market segment representative: Bulk Water Conveyance at Royal HaskoningDHV.

FIGURE 6 Electrical short circuit caused by creeping corrosion between two pins coated with Ni/Pd/Au

IMIESA May 2020

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WATER & WASTEWATER

Addressing water capacity constraints, the City of Ekurhuleni has committed to building 29 reser voirs during the period 2018 to 2021, adding an additional 550 Mℓ of storage capacity.

W

ithin the mix, Superway Construction was awarded the contract for a new Brakpan facility, going up adjacent to the existing reservoir at Sallies Village. The new 18 Mℓ reservoir measures 8.2 m in height and 60 m in diameter, topped by a slightly sloped concrete roof.

AfriSam secured the contract to supply 2 500 m3 of readymix concrete, based on its ability to meet the stringent quality specifications. All concrete supplied was as per the consulting engineers’ material specification for an impermeable water retaining structure. SANS 2001-CC1-2012, the specification for structural concrete used for this project, called for fly ash as a supplementary cementitious material.

The slump was initially specified at very low levels between 10 mm and 60 mm. This was of concern considering the high minimum binder content specified, ambient temperatures and the need to pump the concrete. Close consultation

Custom mix for new reservoir between AfriSam’s technical team, Superway Construction and the consulting engineers resulted in an agreed-on slump of 125 mm in conformance with SANS 878.

Tight shrinkage The careful calculation of the water:cement ratio – not exceeding 0.5 – ensured that the tight shrinkage specification of between 0.3 mm and 0.45 mm was met. A crystalline waterproofer was incorporated into the mix to further enhance permeability properties.

Additionally, a Chryso curing compound allowed for adequate cementing reactions to aid strength gain, impermeability, abrasion resistance and durability. A well-graded aggregate was used for this special application.

This custom mix underpins AfriSam's capability in designing and supplying a fit-for-purpose readymix concrete – in this case, a workable mix that accommodated placing techniques and met the project specification.

Readymix pours The reservoir was constructed in three lifts for the full circumference, ensuring stability for the reservoir

walls. This necessitated a continuous supply of readymix concrete and AfriSam allocated seven readymix trucks to each pour. When required, this was increased to 12.

The roof was formed in a single 630 m3 pour. Jurie Moolman, site manager, Superway Construction, says the biggest challenge was to ensure an acceptable finish over such a large area.

Comments Queen Mabunda, territory sales manager, AfriSam: “Our extensive experience and knowledge within the readymix sector and access to resources within the company, including the Centre of Product Excellence, allowed us to provide Superway Construction with the readymix solution it needed on this project.

“Further, our stringent quality control measures at AfriSam’s Sub-Nigel plant provided the assurance that the customer needed when it came to consistent product quality,” she adds.

Work on-site commenced in May 2019, with a contract completion date set for June 2020. Prior to the lockdown, Superway Construction was on track to hand over the project by the end of May, ahead of time and on budget.

WATER & WASTEWATER

GET

water wise South Africa is now classified as a water-scarce countr y, and its water resources are under tremendous pressure from a growing population, ongoing development, pollution, wetland destruction, alien invasive plants and the effects of climate change.

T

he amount of water available for use remains the same and, despite plans to increase storage capacity through the building of new dams or water transfer schemes, predictions are that the demand for water at current use rates will likely outstrip supply by 2030.

The need to change attitudes Most water systems in South Africa are already at the point of overutilisation. This trend cannot continue. Water conservation is critical to all South Africans.

The only answer to this dilemma lies in people changing their attitudes and behaviour to use water more wisely.

To achieve this goal, Rand Water’s ‘Water Wise’ campaign has been forging partnerships and developing relationships for over two decades, bringing its messaging to Gauteng and South Africa.

All water users – from bulk customers (such as municipalities and mines) to business, the hospitality industr y, local authorities and individual households – must use water efficiently and sustainably. A family of four can use up to 1 200 ℓ/day of water in the home.

This is a ver y large amount considering that many people in the world use as little as 25 ℓ/day of water per person, or 6 kℓ/month of water per household.

It has been estimated that the world average of per capita water use is 185 ℓ/day, which means South Africans use approximately 20%, or more, water per person per day than the global average.

Water Wise water calculator Have you ever wondered how much water you actually use every day or how much water is lost through your leaking tap?

The new Water Wise calculator allows households to answer a few easy questions and calculate their water usage. Using local averages and national benchmarks, the calculator will indicate roughly how much water the household uses and the approximate rand value of that water. The calculator can also help you identify where you use the most water so that you can focus on implementing water savings where it counts.

To calculate your water usage, visit calculator.waterwise.co.za:92.

water. After half an hour, take a reading on your water meter. Take another reading an hour later, ensuring that absolutely no water is being used. If there is a difference between the two readings, it may indicate a leak. The leak may be in the building, in the garden if you have a garden hose or irrigation system, or in underground water pipes.

It is good practice to read your meter regularly and perform leak tests to help save both water and money.

Water Wise’s leak fixing library offers a number of tools to help you identify and fix leaks: www.waterwise.co.za/site/ water/Water_use-in_the_home/Leaks_ and_Leak_Fixing.

Meter reading and leaks In the system, water leaks and nonrevenue water (accounting for around 31% in Gauteng) can be very costly and are a large contributor to water wastage in South Africa. Knowing how to read a water meter is the first step in determining whether you have a leak.

To test for leaks, ask all members of your household or business to stop using

For more information on how to become Water Wise, visit: facebook.com/WaterWiseRSA twitter.com/water_wise www.waterwise.co.za/site/home.html

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WATER & WASTEWATER

Embrace advanced technologies Water-resilient cities can only be achieved through decentralised systems that harness appropriate advanced technology solutions.

By Musawenkosi Ndlovu* FIGURE 1 A typical turnkey 6 Mℓ/day advanced technology water treatment plant

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he cost of water production has more than tripled in recent years. As the traditional technologies used in our manually operated water treatment plants fail to keep up, operating and maintenance costs have soared, leading to higher water tariffs.

However, intelligent solutions can be employed to reduce the cost of water production and ultimately build waterresilient communities.

Traditional water treatment Traditional water treatment plants use a combination of coagulation, sedimentation, filtration and disinfection to provide clean, safe drinking water – technology that dates to the 20th century.

Conventional technologies are mainly centralised, as they are mechanically intensive and involve substantial civil works; however, these centralised systems typically result in a loss of water through

leakages as well as high water pumping costs, and pressure monitoring becomes a challenge.

Implementing intelligence South Africa does not have to reinvent the wheel, but rather add intelligence to existing systems to maximise their efficiency.

One example of this is through the implementation of membrane technology, which offers several benefits, namely: • can be decentralised • 80% reduced footprint • 80% chemical cost reduction • fully automated (no labour costs) • resultant low-water tariffs • reduced pump sizes.

Benefits of advanced technology Using advanced technology to treat water has a positive effect on capital and operating costs.

For starters, the use of membrane technology eliminates flocculation,

FIGURE 2 Typical water treatment process flow diagram

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IMIESA May 2020

sedimentation and sand filtration. This optimises the efficiency of the system and substantially reduces the amount of chemicals dosed into the system.

Table 1 shows the typical volumes and costs of water treatment chemicals used by a conventional water treatment plant.

Using these numbers, a municipality would spend R1.43/m3 on chemicals to treat 6.5 Mℓ/day of water – amounting to R9 321 per day. However, by using advanced technology water treatment methods, like membranes, chemical usage can be reduced by approximately 80%.

Furthermore, automated advanced technology water treatment plants have a high recovery rate. The waste generated through the treatment process is minimal and usually disposed of down municipal drains. This eliminates any sludge drying beds, which can occupy 1 500 m2 on a plant that produces 6 Mℓ/day. In addition, the modular orientation of the advanced technology water treatment skid makes increasing capacity easy to implement, as it just takes the addition of membranes.

These plants are also light on mechanical installation, using smaller, lighter pumps.

The elimination of sedimentation and settling reduces the overall amount of civil and mechanical works needed, and thereby reduces both capex and opex costs.

Municipalities rely on revenue collected from water sales to maintain infrastructure and the servicing of water production. Due to superior reliability and the elimination of human error in the production of water through advanced treatment methods, plant

WATER & WASTEWATER

availability is maximised and the water quality is not jeopardised.

Conclusion and recommendations It is critical for South Africa to follow innovative ways of producing water efficiently.

The implementation of advanced treatment technologies and the decentralisation of these systems is the future of the water industry.

These advanced treatment technologies

FIGURE 3 Water treatment process flow diagram with the introduction of membrane technology

TABLE 1 Cost of water treatment chemicals for a conventional water treatment plant

Chemical name Aluminium sulphate Sodium aluminate Soda ash Chlorine

Dosage (ppm) 202 39 50 10

reduce the cost of producing water, as they occupy smaller footprints, are environmentally friendly and more cost-effective â&#x20AC;&#x201C; by using

ZAR cost (ppm) 5 6 3 4

Total cost R1 010.00 R234.00 R150.00 R40.00

significantly less chemicals â&#x20AC;&#x201C; and by reducing the labour component along with the potential of human error.

To ensure that the system works perfectly, it is important to use equipment that has been industry-tested and that has integrity test certificates. It is also vital to conduct proper feasibility studies and data analysis before designing a plant, as abnormal variations in the feedwater can influence the percentile availability of the plant. Lastly, the proper running of a plant is key to ensure that it operates within its design specifications, and this will ultimately help to ensure that membranes and other capital equipment last. *Musawenkosi Ndlovu is the director of QFS.

GEOMATICS

The mapping of subsur face utilities is becoming increasingly valuable, as projects can be planned with confidence and peace of mind, knowing that either the site is clear, or that areas of interest have been inspected and repor ted on. By John Hughes, Geometric Surveys

Underground utility scanning and mapping

U

tility scanning, or subsurface services detection, is the process of identifying and mapping utility mains that are underground. These mains may include lines for telecommunication, electricity distribution, natural gas, fibre-optic cables, traffic lights, streetlights, stormwater drains, water mains, wastewater and sewer pipes.

Engineers, project managers, town planners, architects and all other professions involved in the construction industry need to know where underground services are located before they start planning and design.

The role of the professional land or technical surveyor is critical in the supply of accurate spatial information and underground services. It is the task of a land surveyor to position the underground services that are essential for future design and planning for brownfield projects and the reconstruction of infrastructure.

The best solution is to appoint a registered person to execute the survey and utility scanning where the advantage is that the surveyor can add the detected services seamlessly to their data. The engineer therefore has one

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IMIESA May 2020

Engineers, project managers, town planners, architects and all other professions involved in the construction industry need to know where underground services are located before they start planning and design

Various benefits Some benefits of subsurface utility scanning include: â&#x20AC;˘ non-disruptive and non-destructive methods

data set and is not concerned if the surface markings of the detected services disappear.

In this respect, the Geomatics Professions Act (No. 19 of 2013) clearly stipulates that a person must be registered with the South African Geomatics Council (SAGC) to perform survey work. Anyone who breaches this stipulation is committing a criminal offence. Itâ&#x20AC;&#x2122;s also important to understand that there are various categories of surveyors: the correct discipline and survey category must match the specific project outcomes (see www.sagc.org.za or www.sagi.co.za).

GEOMATICS

• improved and updated asset register • assists with the design phase and flags possible utility conflicts that may require redesign • protects existing services from being damaged during construction • avoids contractor change orders • fewer damaged utilities, which means fewer penalties and construction delays • local communities are not affected by damaged utilities, which could cause health risks as well as take a long time to repair with large associated costs.

Different detection and location methods must be used because of the many different types of materials that go into manufacturing each of the different types of underground services.

Electromagnetic equipment, consisting of a transmitter and receiver, is best suited to locating metal pipes and electric cables.

For other types of pipe, such as plastic or concrete, other kinds of radiolocation or modern ground-penetrating radar must be used.

All found services are indicated on the surface by either chalk marks or with spray paint marks for visual inspection by the client. These marks are then captured by land survey and this information is then processed and represented on the feature survey drawing of the site.

General procedures Precision locator/high-power transmitter combination The precision locator is most effective at locating buried cables and metal pipes. The project area is broken down into sections and the site is covered by walking in a grid formation where the cross-section intervals are approximately 20 m in size. This process helps identify areas that need to be inspected in higher detail.

This is particularly important in more built-up areas where the services network becomes denser – e.g. at a road intersection where there might be stormwater, fibre-optic cables, traffic light connectivity network, electric cables and so on traversing the site.

The image of a bowl of spaghetti representing the services network comes to mind.

• Accuracy: ±10% of depth (i.e. 0.1 m if service is 1 m deep) • Depth: ±5 m in perfect soil conditions, ±3 m can be a reasonable expectation

Ground-penetrating radar (GPR) GPR utilises a short burst of radiofrequency energy radiated into the ground to detect discontinuities.

These discontinuities can be cavities, voids, buried objects, filled areas, non-conductive pipes, etc.

With GPR equipment, the site also needs to be inspected similarly in a grid pattern across the site. In order to identify the service type, a source of where the service is exposed – either by opening an inspection manhole or where the service becomes visible – is required. This is because GPR is unable to detect the service type. Linear obstructions or anomalies will be indicated on the GPR unit’s screen, with the depth clearly visible.

There are limitations with this technology; it is possible that a limited number of services will not be detected. A good example of this is the old clay pipe used to carry outflow wastewater. The clay pipes are not conductive, as the equipment relies on conductivity to be able to detect an anomaly. Coupled with that, the ground in which the clay pipe is planted returns similar signals to that of the soil type and the result is that the service is missed. In cases like this, a sonde needs to be inserted into the pipe, which has good conductivity properties, allowing one to locate the service more easily.

• Accuracy: X, Y – sub 0.10 m Z – In general, it is sub 10% (if service is 1 m deep, the accuracy is 0.1 m).

• Depth: ±8 m in perfect soil conditions, ±3 m can be a reasonable expectation.

Conclusion If sound survey and solid utility scanning practices are followed, an accurate reliable asset register can be achieved. This allows engineers, architects and all other spatial professionals to achieve their objectives with the least amount of interruptions, and budget overruns, due to services not being damaged.

For further information, please contact the author at survey@gscc.co.za or +27 (0)11 462 2308 / +27 (0)82 825 8114.

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VEHICLES & EQUIPMENT

The Polihali Western Access Road (PWAR) is a new route forming par t of Phase II of the Lesotho Highlands Water Project (LHWP), with Rumdel Cape awarded the contract for the construction of a 33.5 km section.

Forming a route to Polihali

S

pearheading Rumdel Cape’s intensive PWAR programme is a fleet of machines supplied and supported by Bell Equipment, functioning optimally at an average altitude of 2 300 m above sea level. Rumdel Cape has a long history with Bell Equipment, especially the company’s articulated dump trucks (ADTs).

“We have Bell B20D ADTs that date back to 2003 and 2007, with some reflecting 26 000 hours of reliable service; despite those massive hours, they have not been rebuilt,” says Derick Smit, plant manager, Rumdel Cape, adding that this project has provided the perfect opportunity for Rumdel to update its ADT line-up with new models.

By their own admission, Smit and his colleagues researched the entire ADT market but, due to the longevity and reliability of their Bell ADTs, decided to stick with the Richards Bay marque. Rumdel Cape sold four older Bell B25D ADTs out of hand and bought four new Bell B25E 6x4 ADTs along with a Kobelco SK380LC-8 excavator – the latter also supplied

by Bell Equipment.

Rumdel’s contract scope entails the hauling of some 1.3 million cubic metres of material to construct its access road section. Of this, 1.1 million cubic metres must be blasted in order to move it. Another challenge is that of

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Rumdel Cape has invested in a fleet of four B25E 6x4 trucks and a Kobelco SK380LC-8 excavator for a 23-month contract on Phase II of the Lesotho Highlands Water Project

countering constant high winds that kick up dust. About 5 km of the road site is also above the snow line, and snowfalls can occur at any time of year.

Safety and performance “We’ve been impressed by the countless safety features of the new Bell B25E ADTs,” Smit continues. “The first feature that comes to mind, which is particularly applicable to safety on the LHWP, is that the truck won’t tip if it stands at an angle that differs more than nine degrees from horizontal. Other features such as anti-rollback, a park-brake that kicks in timeously and the ‘i-tip’ feature all help to make our operations safe.

“Another feature that we enjoy is the Fleetm@tic monitoring system that gives us

accurate figures on cycle times, loads carried and fuel consumption, which at this point varies between 8 and 12 litres an hour – figures that are well within our budget,” he explains.

Working alongside its ADTs is Rumdel’s recently acquired Kobelco SK380LC-8 38 t excavator. “An adequate loading tool for our Bell B25 ADT fleet would probably have been a 30 t machine, but as we’re confident of the Kobelco’s longevity, and thinking ahead to future work, we’re pleased with the slightly larger capacity,” he adds.

“Our long-term thinking is to have one supplier for both excavators and haulage tools. We believe that this will make maintenance and spares acquisition easier, as we’ll be dealing with one supplier with whom we already have an established relationship,” Smit concludes.

L-R: Johan Sprong (workshop manager, Rumdel Cape), Derick Smit (plant manager, Rumdel Cape) and Luc Hannan (sales representative, Bell Equipment)

SUSTAINABLE ENERGY FOR A

Brighter Future

INSIDE The long wait is over – or is it? 49 Transitioning to a greener economy 51 Implications for SA’s electricity supply industry 52 Prospects of nuclear in SA’s energy mix 55

Your partner in sustainable power production We at Helukabel have a firm belief in the need for sustainable clean power solutions ,not only in South Africa, but globally.

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As a global company we continually strive to find new technologies to ensure that our products deliver optimal performance under the demanding environmental conditions often associated with sustainable renewable power production. From large wind farms through to roof top solar installations our cables and accessories can be found.

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Cables for communication in copper and fibre construction ensure that from start to finish our cables will seamlessly integrate into the system.

Making these connections even more secure and seamless are our range of tools and accessories.

Connectors for communication cables through to glands, our range of cable management accessories are rigorously tested to ensure their continued performance.

Whatever your cable and accessory requirements might be, whether your project is large or small Helukabel is ready to advise and assist with you.

Contact us to discuss you requirements at sales@helukabel.co.za or +2711 463 8752

ENERGY

The long wait is over – or is it?

Taking strain

The long-awaited revision of the Integrated Resource Plan (IRP) was released in October 2019. But how long will we have to wait before implementation begins?

By Davin Chown*

W

hat the IRP signals is important: over and above outlining what the future energy mix could look like, it also suggests a roll-out plan and its timing.

More importantly, the revised version also talks specifically about key actions the Department of Mineral Resources and Energy (DMRE) needs to undertake.

What it is silent on, however, is the fact that this new plan may cost South Africa R100 billion per annum more than the leastcost version of the IRP. What we also know is that Minister Gwede Mantashe of the DMRE has said that the government wants to see a “just transition plan” in a way that benefits all current stakeholders, and not just a few.

There is provision for the retirement of Eskom’s ageing coal fleet, which will be replaced with some new (‘clean’) coal, renewables and gas. Clearly the future mix is oriented towards renewables, storage and gas, and the real step forward is the sizeable allocation to storage in the IRP. What is not clear is why, given the over-reliance on coal and the electricity supply crisis we are in, we are not preparing for a more rapid transition and moving away from this fossil fuel reliance, gas included, when we have storage technologies able to play a significant transition role.

The return of load-shedding demonstrated, yet again, that the electricity system is taking strain and that the DMRE and Eskom can’t really afford to dither. If we look at the assumptions in the IRP about energy availability, it’s obvious that this is already out of kilter. So too are the import scenarios: the gas solutions from Mozambique still seem a way off, yet the rapid decline in storage costs now allows for peak-time consumption to be supplied from renewable energy (RE) sources.

Add to this the assumption made that, with Kusile and the committed renewables projects, the country requires no real new build until 2025, it’s clear that the assumptions must be urgently revisited. Many are asking whether the IRP has perhaps been overtaken by reality. This clearly seems to be the case. And if we are to grow the economy, the IRP seems lost at sea with its assumptions and projections.

The IRP makes provision for 500 MW per year of decentralised generation, probably mostly solar. We know that the renewables industry is capable of much more, but it’s a very good start. What we need now is the regulation to allow this uptake in the market to move forward unhindered. But here too, we must wait. Storage can be procured on a private-sector-funded IPP model, rather than by Eskom taking out more loans, and such storage can be deployed as large stand-alone sites, co-located with RE generation or via a collection of smaller storage units deployed throughout the distribution network (or even behind the meter).

What are we waiting for?

Politics, policy and regulation are the clear reply.

Efficiency must be the single-minded focus of all involved; however, not everyone is happy with the proposed future mix. Some interest groups are unhappy with the fact that nuclear is not playing the role it should be, even though the current plan is likely to cost R100 billion

a year more than the least-cost plan would, given the inclusion of nuclear. Some don’t like independent power producers, while others want unfettered access to the grid and no government interference in how they generate their electricity.

Implementing our plans We have a workable, solid IRP: one that is implementable and fundable; one that spurs investment interest; one that clearly means new skills will be developed, potential new component manufacturing created; and one that creates new jobs especially in technologies like storage and energy component manufacture.

What we need is someone to fire the starter’s gun and enable a new renewables procurement round based on the framework of a just transition plan; open up the municipal regulatory framework to allow for the rapid roll-out of embedded generation; allow a willing buyer, willing seller market to rapidly unfold; and restructure Eskom.

With Eskom as a slimmer, streamlined, highly efficient facilitator, alongside regional distribution operators, South Africa would have a highly efficient, responsive system that would help fuel economic growth. But we need that starter’s gun to be fired. The time for debate is over. Implementation is critical. *Davin Chown is a board member of the South African Energy Storage Association.

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ENERGY

Transitioning to a greener economy As South Africa continues its journey of transitioning to a greener economy, the country is asking the energy sector to fast-track procurement and calls for the implementation of the 2019 Integrated Resource Plan (IRP). By Ntombifuthi Ntuli*

T

he added wind energy allocation in the 2019 IRP will reduce the cost of energy, improve the countr y’s competitiveness and help boost the economy. The procurement of new capacity is not coming online quickly enough in order to close the short-term generation capacity gap. Thus, the countr y remains shor t of generating capacity and outages will continue when increased winter-demand arrives. Additionally, as the countr y eases out of lockdown, load-shedding will once again be on the cards.

The countr y’s 2019 IRP outlines increased allocations for wind power, which will contribute 18% of the countr y’s electricity by 2030. The wind sector is happy with the apportionments of the IRP, as it is reflective of the comments we submitted during the public consultation process.

The latest plan, which maps out the energy mix for the next 10 years, envisions the nation’s electricity production capacity rising considerably by 2030. It makes provision for a significant roll-out of renewable energy and storage. According to the Minister of Mineral Resources and Energy, Gwede Mantashe, Eskom has already commenced work on a utility-scale

batter y storage system, which allows for a more diverse energy mix.

The South African Wind Energy Association (SAWEA) sees energy constraints as a clear symptom of Eskom’s reduced energy availability factor and a reminder that the countr y needs to procure new generation capacity, expecially in light of government’s decommissioning plan for ageing coal power stations.

Earlier this year, President Cyril Ramaphosa actively prioritised regaining investor confidence and specifically set an investment growth target of R1 trillion over the next five years, which the Renewable Energy Independent Power Producer Procurement Programme will help deliver.

We now await the promised Ministerial Determination and a clear timeline to kick-start increased renewable power generation to give effect to the 2019 IRP. But this is only the first step in delivering new power into the grid.

Thereafter, the industr y will wait for an RFP (request for proposal), the announcement of preferred bidders, and the financial closure period (which takes about 12 months), before the power purchase agreements are signed.

Thereafter, construction can commence,

with new projects reaching commercial operation within 18 to 24 months.

Decentralisation offers new opportunities SAWEA sees municipalities being allowed to procure from independent power producers (IPPs) as a game changer.

An announcement by Mantashe in early May has gazetted for public input the draft amendments to the Electricity Regulations on New Generation Capacity.

This gives effect to Ramaphosa’s 2020 SONA announcement that municipalities in good financial standing will be enabled to develop or procure their own power generation.

To shift away from a centralised monopoly to a more efficient decentralised generation model will increase competition and drive down energy prices, which will ultimately stimulate the economy and support the growth that South Africa is seeking.

With private sector participation in the energy generation business, where municipalities and large-scale private power users can purchase power directly from IPPs, the benefit of introducing competition into the electricity generation market will naturally result in price reductions, while increasing generation capacity.

We need the market to be opened for IPPs to be able to supply electricity to the private sector. Private renewable energy producers can supply electricity to intensive users at a rate of 25% less than Eskom mega-flex tariffs – this includes municipalities. *Ntombifuthi Ntuli is the CEO of the South African Wind Energy Association (SAWEA).

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ENERGY

South Africa is on a low-carbon trajector y and many of the existing coal-fired power stations will have to be replaced within the next 10 years. So, what are the options and alternatives? By Dr Rob Stephen*

Implications for SA’s electricity supply industry

I

nverter-based (renewable) systems such as PV and wind provide cheap energy, since the fuel is free; however, they do not provide the full suite of attributes required for a power system.

Ideally, one needs to provide a balance to ensure the inverter-based resources are complemented by other generation types to ensure a stable and reliable supply of electrical energy.

One of the major areas requiring attention is inertial response for frequency control.

The Integrated Resource Plan (IRP) mentions that – due to the expected low penetration of renewables, i.e. below 40% – this will not be an issue before 2030. However, at low loads with high solar and wind generation, it is possible that the inertia required may be inadequate well before 2030.

Studies need to be done to ensure that either the decommissioned plants are converted to synchronous condensers or that inverter-based resource generation is curtailed. Energy storage systems should be included in the inverter-based generation packages. Markets should be introduced with a move away from ‘take or pay’ power purchase agreements. The ability to curtail inverter-based generation should be permitted with limited penalties (which are payable by customers).

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What about the infrastructure?

The IRP as proposed does not mention the infrastructure needed to incorporate the proposed generation. Eskom estimates that an amount of R20 billion is required for integration. This includes 2 650 km of transmission line. A major risk to the success of the plan is the acquisition of ser vitudes for the lines. A ser vitude can take up to 10 years to acquire. The IRP, however, requires generation to be available in two to three years.

Another aspect to consider is that the per formance of current coal-fired power stations is worse than anticipated. The proposed IRP, if implemented according to plan, may not be suf ficient to ensure a reliable supply of electricity in the short term.

Government’s recently issued RFI (request for information) intends to address this by inviting power producers to tender for short-term generation, which could mitigate the need for load-shedding.

This is an excellent initiative and, although it may be criticised as being too little too late, I feel it is a step in the right direction.

Responding to the road ahead The reality regarding the future generation and load mix is as follows:

• I nverter-based resources will continue to drop in price, providing low-cost energy, albeit erratically.

• Storage costs are likely to continue dropping, which can provide short-term energy and ancillar y ser vice support.

• Demand for electrical energy is likely to increase. The supply of electrical energy will be varied between households, utilitysized generation from independent power producers, and the current utilities.

• The operation of the grid will become more difficult, with variable generation in size, duration and location causing risk to frequency, fault level and voltage support.

How can South Africa respond to this scenario? The answers are as follows: • L earn from other countries: the deregulation, advent of markets and renewables has been in place for the last 20 years. Solutions have been found to almost any scenario and engineers are continuing to develop others.

• R educe bureaucracy by creating markets: at present, applications need permission from government, including the regulator. It may be more efficient to create a market for generation and allow authorities to monitor the market adherence rather than investigate

ENERGY

each potential generation source. Again, solutions in Denmark and Germany can be investigated.

• The acquisition of ser vitudes needs to be expedited dramatically, also through reduced bureaucracy.

• Plan for small, rapidly installed, flexible generation units that can be placed where needed with short lead times. The days of large baseload mega plants are limited and may lead to late installation or oversupply.

• Design the grid components for robust plans that can cater for large variations in load transfer and reduced initial capital costs. This is due to the load scenario being highly variable and uncertain.

Engaging with CIGRE What does this mean to CIGRE members?

Founded in 1921, CIGRE is an international non-profit association for promoting collaboration with experts from all around the world by sharing knowledge and joining forces to improve electric power systems.

It consists of over 10 000 members from

more than 90 countries. The organisation’s aim is to transfer technical knowledge and to develop solutions to problems faced by members. This is achieved by forming working groups consisting of international experts who are knowledgeable in specific areas.

One fortunate aspect of the challenges Eskom faces is that other utilities have faced similar ones over the past two decades. CIGRE has developed a number of solutions, such as market design, grid operation with a high penetration of renewables, protection philosophy and design with var ying fault levels, and planning in an uncertain environment. It is possible, therefore, that all the issues faced by Eskom and the electricity supply industr y could be successfully addressed by engaging the international experts in CIGRE. Another exciting development is the rapid generation and use of hydrogen as the energy of choice for transport and other sectors. Renewable energy generation, when in surplus, could be used to generate hydrogen from water. This ‘green’ hydrogen

can be exported or used locally for trains, trucks and other applications. This would mean that South Africa could maximise the installation of renewable energy generation if the grid curtails the output, as the balance could be used to generate hydrogen for export or local use.

Conclusion We live in exciting times. For tunately, solutions exist for most of the challenges the South African electricity supply industr y, including Eskom, is facing. We need to leverage the information and expertise of organisations such as CIGRE and learn from other countries. That way, we can best ensure a reliable, efficient and sustainable electrical energy supply into the future.

Author’s note: The comments provided above are my own and not necessarily those of CIGRE or Eskom. *Dr Rob Stephen is the international president of the International Council on Large Electric Systems (CIGRE).

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ENERGY

Prospects of nuclear in SA’s energy mix Although the dream of South Africa becoming an international player in the area of nuclear energy has not yet materialised, the countr y still has the only nuclear-driven power station on the continent. Sadly, no new nuclear plants before 2030 have been listed as electricity generating technologies in the IRP 2019.

By Knox Msebenzi*

S

outh Africa’s Koeberg Nuclear Power Plant (KNPP), the only nuclear power plant on the continent, opened in 1984 and has since provided electricity reliably and consistently.

In around 2007, Eskom got permission to have as much as 20 GW of new nuclear power installed. The approach adopted by government was not so much to procure nuclear power plants, but to build a capability by localising the industr y in an aggressive way. This is when the Nuclear Industr y Association of South Africa (NIASA) was formed.

The vision was that, like South Korea, South Africa would become a major player in the nuclear supply chain all over the world and perhaps even an exporter of the technology in its own right. This dream was on the brink of materialising with the Pebble Bed Modular Reactor (PBMR), when a political decision to terminate the programme was taken.

new source of power, largely embraced by the international community riding the wave of climate change and other environmental considerations of sustainability.

The energy mix debate in South Africa attracted a lot interest from international

and local non-governmental and civic organisations, whose thrust was to lump nuclear technology with coal as anathema to the environment and therefore argue that nuclear technology be excluded.

Nuclear power and renewable energy should not be seen as competitors, but as complementar y. All the BRICS countries are seriously pursuing both nuclear and RE.

Anti-nuclear sentiment The environmental argument augmented with the

was

Nuclear power in the IRP The Integrated Resource Plan (IRP) of 2010–2030 made provision for a reduced amount of nearly 10 GW, owing mainly to the entrance of renewable energy (RE) as a

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ENERGY

anti-fossil-fuel lobby, cost issues and the linkage to corruption labelled against nuclear. A figure of R1 trillion was quoted by the media as being the cost of nuclear.

This figure was accepted by many as fact.

There has also been a narrative that equated nuclear with corruption. All in all, the debate was highly politicised, with all manner of people leading the debate as experts on energy, while in many instances the real experts were prevented by protocol from discussing the topic publicly. The anti-nuclear lobby was thus somewhat successful in waging a protracted campaign to get nuclear thrown out of the IRP, and the Draft IRP of 2018 reflected only 2.5 GW of new nuclear by 2030.

The IRP 2019 states, “In the period prior to 2030, the system requirements are largely for incremental capacity addition (modular) and flexible technology.” The 2.5 GW initially contemplated in the IRP 2018 does not appear, as government is emphasising the approach of small modular reactors, in keeping with the principle of doing it “at a scale and pace that flexibly responds to the economy and associated electricity demand.”

It also states that upfront planning with regard to additional nuclear capacity is requisite, given the greater than 10-year lead time, for timely

decision-making and implementation.

In addition to this, the government has decided to extend the life of KNPP. In view of this, nuclear does not appear in the new additional capacity up to 2030, but the policy is ver y clear that work must begin forthwith to realise this goal. NIASA also believes that it would be wise to have a contingency plan to add reliable baseload power should the 2.5 GW Inga Hydroelectric Scheme be either delayed or not materialise. Furthermore, as we decommission coal plants, they should be replaced by another source of reliable, dispatchable power.

Water-energy nexus The water-energy nexus identified in the IRP 2019 offers a huge opportunity for further nuclear expansion. South Africa is endowed with uranium (and other potential nuclear fuels) and the conjunctive deployment of small modular reactors in coastal areas for electricity generation and water desalination is a low-hanging fruit. Water is a commodity that, unlike electricity, can be stored easily.

South Africa’s coastal areas currently receive power mainly from Mpumalanga.

If nuclear plants were to be built in these coastal areas, any plant failures on the remaining coal-fired power stations could be mitigated by load-shedding water

desalination capacity, without installing any additional transmission capacity.

We believe that if sufficient capacity were installed, it would be possible to turn certain areas in the Northern Cape and Karoo into green zones. A number of Middle Eastern countries could provide ample and appropriate case studies for South Africa to emulate.

Flexibility of supply One of the criticisms of nuclear power plants is that they are inflexible. It is because they are designed that way. Since it makes no difference, cost wise, to run at 30% or 100% capacity, why would one want to reduce the power output? Nuclear power stations are designed to run flat out, at full power. However, the French power system, with its high proportion of nuclear in the energy mix, has some nuclear plants designed to be flexible enough to enable a load-following capability.

Benefits of a nuclear build programme The expansion of nuclear power generation in South Africa would provide the necessar y bedrock to further develop many other nuclear technologies that are not power related. Examples that come to mind are applications in medicine, agriculture and industr y. In the case of medicine, the wellknown radio isotope manufacturing plant at Pelindaba is a salient example.

Nuclear technologies are also used in a variety of applications in disease control and the irradiation of fruit and vegetables to extend their shelf life. Scaling down the nuclear power programme may have an undesirable, negative knock-on effect on other nuclear technologies.

As the undisputed industrial leader on the continent, South Africa should lead the way by strengthening its civil nuclear capability. Many African countries have either embarked, or are about to embark, on some nuclear programme. It is no secret that they would be looking for assistance in doing so. This would provide business oppor tunities for the countr y to expor t skills and exper tise. NIASA, therefore, believes the future of nuclear is ver y bright. *Knox Msebenzi is the managing director of the Nuclear Industr y Association of South Africa (NIASA).

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COVID-19

Considering the consequences of Covid-19 The construction industr y, like many others, was dramatically affected

by South Africa’s hard lockdown, with all non-critical construction sites shut down.

By Danielle Petterson

W

hile many professionals in the built environment may have been able to work from home during the lockdown, they were likely unable to earn money for their professional services, which are usually charged on the progress of the project on-site.

Fur thermore, pipeline projects still in the planning phase will be faced with massive uncertainty, which may further constrain the earning potential for all

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professionals, notes Larr y Feinberg, executive director, Association of South African Quantity Surveyors.

However, the construction industry also has the potential to create employment opportunities to cushion the impact of the anticipated increase in unemployment in the immediate aftermath of the lockdown.

Task team established In a bid to collectively unlock relief measures for the industry, several key industry bodies came together to form the Construction Covid-19 Rapid Response Task Team (CCRR19TT), namely: Master Builders South Africa (MBSA), Association of South African Quantity Surveyors (ASAQS), Western Cape Property Development Forum (WCPDF), South African Institute of Architects, Black Business Council in the Built Environment (BBCBE), Consulting Engineers South Africa, Association of Construction Project Managers, South African Institution of Civil Engineering, South African Black Technical and Allied Careers Organisation, South African Women in Construction, The Concrete Institute of South Africa, Cox Yeats Attorneys, and Master Builders KwaZuluNatal as the convener.

Among others, the task team intends to: • explore relief measures specific to the sector • support emergency procurement for the next 12 months

• engage government on 30-day payments • partner with the public and private sectors on infrastructure development.

Lockdown effects With the construction industry already under immense pressure prior to the lockdown, Gregory Mofokeng, CEO, BBCBE, says that a significant number of companies may not survive the tough post-lockdown conditions, with many likely to opt for either voluntary liquidation or business rescue.

Deon van Zyl, chairperson, WCPDF, believes that built environment professions, such as constructors (civil and building), artisans and, most importantly, labourers, will feel the immediate impact of the lockdown the most. “An industry that normally functions on a no-work, no-pay formula is seeing its labour force really suffer,” he says.

Van Zyl expects the commercial property sector to experience follow-on consequences from the lockdown, as developers struggle to find end users and development finance comes under pressure.

The impact on SMMEs is of great concern.

“Should the SMMEs be confronted with the same set of circumstances as prior to the advent of Covid-19, there will be a significant number of casualties. Sadly, this loss of capacity will also impact negatively on the sector’s ability to create the muchneeded jobs in our sector and our economy,” comments Mofokeng.

COVID-19

Van Zyl calls for short-term relief to be increased and the formalisation of these SMMEs into the supply chain process to ensure survival and future growth.

Suggested measures In consultation with its members, BBCBE has put forward a number of interventions for consideration. The first is that government and private sector clients should pay invoices in the system with immediate effect to release much-needed cash flow to the sector.

BBCBE has also called for loan repayment holidays and a fast-tracked process for contractual disputes, which Mofokeng says are likely to increase as a result of the lockdown. Implementation of a specific procurement regime should be used to expedite public sector projects.

The WCPDF has called for the removal of red tape and legislative alignment across all

spheres of government. “The WCPDF calls on all IMESA members in their various roles to actively participate in the breakdown of red tape and to help the public sector return to economic growth through the proactive provision of infrastructure and fast-tracking of investment-related decision-making. We call on government and the private sector to enter into a real partnership of growth-driven investment,” says Van Zyl.

A model for economic recovery One of the first steps taken by CCRR19TT was to motivate for a phased reactivation of the construction sector during lockdown, under strict safety requirements. The task team also called for the activation of planned public infrastructure spending as announced in the medium-term expenditure framework.

“It is an undisputed fact that any country that implements counter-cyclical economic

measures has to have infrastructure investment in its toolkit. The construction industry has one of the highest multiplier effects comparatively speaking and government – in its quest to boost the economy and employment creation – has to prioritise investment in infrastructure,” says Mofokeng.

Feinberg concurs, stating that numerous studies have provided empirical evidence to support the idea that investment in infrastructure directly links to the economic growth of a nation.

“No doubt we will look back at the Covid19 crisis as a seminal moment in the country’s history. It will either be the point where structural reforms are agreed upon and implemented, and where qualified professionals are finally empowered to do what they were trained to do, or the point where final breakdown occurred,” concludes Van Zyl.

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HEALTH & SAFET Y

The essential role of construction ergonomics Construction ergonomics is a subset of health and safety (H&S), although some ergonomists may argue to the contrar y. This ar ticle is intended to provide a brief over view of the subject.

By Professor John Smallwood*

A

ccording to La Dou1, ergonomics (from the Greek ergon, ‘to work’, and nomos, ‘study of’) is literally the study of work, or the work system, including the worker, their tools, and their workplace. He states that “it is an applied science concerned with people’s characteristics that need to be considered in designing and arranging things that they use in order that people and things will interact most effectively and safely.”

Since the first study conducted by the

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ceilings predominate in terms of the elements of buildings.

The impact of poor construction ergonomics Poor ergonomics results in a range of musculoskeletal disorders (MSDs), and sprains and strains predominate in terms of workdays lost, which result in ill-health and absenteeism. Inadequate working platforms and other access marginalise productivity and quality, which contribute to delays and increased costs.

Stages of projects author in 1996, a standard research question has addressed the frequency at which 18 ergonomics problems are experienced. Climbing and descending, the use of body force, handling heavy materials, exposure to noise, bending or twisting the back, reaching away from the body, reaching overhead, handling heavy equipment, working in awkward positions, repetitive movements, and vibrating tools and equipment predominate.

The structure, roof, cladding, installation of services, and

Construction ergonomics issues arise during the six stages of projects, namely project initiation and briefing (S1), concept and feasibility (S2), design development (S3), tender documentation and procurement (S4), construction documentation and management (S5), and project close-out (S6).

The decision regarding the type of building, live loads and height, which are considered as early as S1, influence the choice of structural frame, which affects construction ergonomics due to the implications of reinforced concrete or structural steel frames. Therefore, construction ergonomics can be influenced more during the earlier than the later stages.

HEALTH & SAFETY

The role of clients in construction ergonomics In terms of the Construction Regulations, clients are required to, among other things: prepare a baseline risk assessment (BRA); prepare an H&S specification based on the BRA; provide the designer with the H&S specification; and include the H&S specification in the tender documents. In theory, the tender documents’ H&S specification should schedule the residual hazards, ergonomics included, on projects – e.g. mass of heavy materials such as 390 mm x 190 mm x 190 mm two-cell concrete blocks, and 1 m long precast concrete kerbs.

Project-managing construction ergonomics Construction project managers (CPMs) should address construction ergonomics during all six stages, commencing with the project brief and charter during project initiation and briefing (S1), through constructability reviews during concept and feasibility (S2), and design development (S3), facilitating and reviewing financial provision during tender documentation and procurement (S4), screening the H&S plan before commencement of construction (S5), and reviewing contractor interventions in the form of training, such as H&S induction and toolbox talks. CPMs’ close-out reports (S6) should flag design-originated construction ergonomics hazards.

Designing for construction ergonomics Concept design, detail design, shape of structure, structural frame, enclosing fabric, details, specification of materials, and method of fixing, among others, all impact on construction ergonomics. Ceiling spaces, vertical ducts and the position of fittings affect access during construction and maintenance.

Therefore, design hazard identification and risk assessment (HIRA) and constructability

reviews are necessary to mitigate any negative impact on construction ergonomics and in the fulfilment of designers’ duties in terms of the Construction Regulations.

Should designers not be able to modify the design or make use of substitute materials, where the design necessitates the use of dangerous procedures or materials hazardous to H&S, then their ‘designer’ report that is required to be submitted to the client should schedule the residual hazards on projects.

These in turn should be included in the tender documentation’s H&S specification.

initiation and briefing stage, and should address construction ergonomics during all six stages. Primary contributions should include: inputs to the project brief and charter, BRA, and H&S specifications for designers and contractors; review of the ‘designer’ report and design HIRA process; ad-hoc design HIRA; constructability reviews; review of the principal contractors’ (PCs’) financial provision for construction H&S, and selected PCs’ and subcontractors’ H&S plans; monthly H&S audits; and a project close-out report.

Materials, plant and equipment manufacturers

The construction process

Materials and equipment manufacturers should be mindful of unit size, mass, centroid, surface area, sectional area, constituents, texture and edges. Furthermore, the form of materials’ packaging affects offloading and site handling.

Other interventions such as the provision of handholds can facilitate the handling of blocks.

Plant manufacturers should be conscious and mindful of unit size, mass, centroid, noise and other emissions, and potential hand-arm and whole-body vibration.

Financial provision for construction ergonomics Quantity surveyors and cost engineers should facilitate adequate contractor financial provision for construction H&S, including ergonomics, in bills of quantities, as detailed ‘H&S Preliminaries’. Doing so will ‘level the playing field’ upon tender evaluation, engender adequate contractor financial provision for construction H&S, and facilitate the client’s duty to ‘ensure adequate financial provision’ for H&S.

The role of construction H&S agents (CHSAs) in ergonomics CHSAs should be appointed at project

Contractors can substantially influence construction ergonomics through planning, which includes budgeting resources, programming that affects the sequencing of activities, site layout, circulation routes and roads, temporary works design, vertical access, HIRA and safe work procedures (SWPs), selecting methods and plant and equipment, mechanisation, walkways and access platforms and plant, and handling and positioning of materials. Pre-tender and pre-contract planning are therefore a prerequisite.

Training, optimum coordination of activities and contributors, organising of workplaces, maintenance of plant and equipment, and housekeeping should follow planning.

For further information, please send an email to john.smallwood@mandela.ac.za or phone +27 (0)83 659 2492. *Professor John Smallwood works in the Department of Construction Management at Nelson Mandela University.

Reference 1 La Dou, J. 1994. Occupational Health & Safety. 2nd Edition. Itasca, Illinois: National Safety Council (NSC)

IMIESA May 2020

61

Plaster’s crucial ingredient

Sand is the major constituent of plaster and has a significant influence on its per formance and material cost, says Br yan Perrie, managing director, The Concrete Institute (TCI).

S

outh Africa's context, where natural sands – such as pit, river and dune sands – are almost invariably used, requires plaster sands to be free of organic matter such as roots, seeds, twigs and humus.

This is essential in the case of white or pigmented plasters, Perrie advises.

Any sand being considered for plaster work should ideally comply with SANS 1090, which has requirements to limit organic impurities, clay content and other

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If a sand includes lumps that are not easily broken between the fingers, it is not ideal for use in plaster

requirements. However, it has been found that sands meeting this standard do not necessarily produce satisfactor y plaster.

Conversely, sands that do not meet the standard may produce acceptable mixes.

If a sand includes lumps that are not easily broken between the fingers, it is not ideal for use in plaster. If such a sand must be used, then all lumps should be removed by sieving.

Crusher sands are not generally suitable for use in plaster due to their angular particle shape, although they have been successfully used in rich mixes for special applications, such as the plastering of squash cour t walls and pipe linings.

Limestone or marble crusher sands are commonly used, with white cement, for plastering swimming pool shells.

Perrie says the use of ash as aggregate is not recommended unless it has been thoroughly tested and proven to be sound.

Specialist advice should also be sought if there is any doubt about the content and type of clay in plaster sand.

“Ideally, the sand should have a continuous grading – from dust up to the

Bryan Perrie, managing director, TCI

largest particles. The fractions passing the 0.150 mm and 0.075 mm sieves (fines) are important because they significantly influence the water requirement, workability and water retentivity of the mix,” he explains.

Fines quality control Increasing these fractions results in an increased water requirement with consequent lower strength and higher shrinkage but improves workability and water retentivity. The optimum fines content is therefore a compromise between these properties.

For plasters, a sand lacking in fines may be used with hydrated builder’s lime, mortar plasticiser or masonr y cement, or it may be blended with a fine filler sand. Sand with a good grading is likely to be suitable for use with CEM l or CEM ll A cements without the addition of builder’s lime or

CEMENT & CONCRETE

other products. A sand with excessive fines may be improved by washing or by blending with a suitable coarser sand. The coarser sand could be a crusher sand, provided that the resulting plaster is suitable for the application and gives acceptable results.

For conventional smooth plaster, Perrie recommends that all the sand pass through a sieve with 2.36 mm openings.

For coarsely textured decorative work, the corresponding sieve size should be 4.75 mm. Oversized particles and lumps should be removed by sieving.

For good workability, the particle shape should be acceptably rounded and the sur face texture smooth. The particle shape of natural sands tends to be rounded due to weathering, whereas that of crusher sands tends to be angular or flaky. Some river sands, however, contain newly weathered particles with a rough sur face texture and angular particle shape. These particles are normally in the coarser fraction of the sand and should be screened out.

Assessment criteria A sand may be assessed by doing both of the following: • comparing grading and maximum particle size and, if necessary, apparent clay content, with the recommendations given • making a mix to assess water requirement.

Mix assessment may be done as follows: 1. Mix 2.5 kg of cement and 12.5 kg of

The particle shape of natural sands tends to be rounded due to weathering, whereas that of crusher sands tends to be angular or flaky

Optimum plastering results are dependent on strict material selection, quality control and application technique

sand to a uniform colour on a nonabsorbent sur face.

2. Add water slowly while mixing until the mix reaches a consistence suitable for plaster.

3. I f 2 litres of water are needed, the sand is of good quality. If 3 litres are needed, the sand is of average quality. If 3.75 litres are needed, the quality of the sand is poor; and if more water than that is required, the quality is ver y poor.

Perrie sums it up: “Only ‘good’ sands are suitable for use in all plaster work.

‘Average’ sands may be used for interior plaster, but ‘poor’ and ‘ver y poor’ sands are not recommended and should be avoided.”

INDEX TO ADVERTISERS

Ace Solutions

22

Helukabel

48

Pilecon

OFC

AKS Lining

14

Hidro-Tech Systems

24

Rand Water

IBC

Bell Equipment

IFC

IMESA

4, 64

Copper Development Association Africa 50

Lektratek

26

ELB Equipment

11

Macsteel

OBC

FLIR Systems

54

Mather+Platt

43

SEACOM SMEC

23 17, 57

Stefanutti Stocks

30

Ultra Water

28

IMIESA May 2020

63

I M E S A A F F I L I AT E M E M B E R S

IMESA

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