The official magazine of the Institute of Municipal Engineering of Southern Africa
IMESA
MEDIA
INFRASTRUCTURE DEVELOPMENT • MAINTENANCE • SERVICE DELIVERY
BARLOWORLD EQUIPMENT
CAT reclaimer spearheads road upgrade
DWA
Kimberley
Mossel Bay
Working together
WWTW upgrade
Desalination
Another link for integrated public transport ISSN 0257 1978 Volume 36 No.7 • July 2011 • R40.00 (incl VAT)
p49
Contents
VOLUME 36 NO 7 JULY 2011
23 35 45 50 Desalination
Anaerobic digestion
4HE OFFICIAL MAGAZINE OF THE )NSTITUTE OF -UNICIPAL %NGINEERING OF 3OUTHERN !FRICA
IMESA
MEDIA
Public transpor t
WWTW upgrade
Regulars
Geotechnical
3 President’s comment 5 Editor’s comment
41 A duty of care
Kimberley
INFRASTRUCTURE DEVELOPMENT ͻ MAINTENANCE ͻ SERVICE DELIVERY
Cover story 6 A new super-class highway
Government perspective 10 Working together for economic growth
45 Three key WWTW 47
upgrade phases Improvement of gravel roads
Transportation 49 Another link for integrated public transport
BARLOWORLD EQUIPMENT
CAT reclaimer spearheads road upgrade
DWA
Kimberley
Mossel Bay
Working together
WWTW upgrade
Desalination
Another link for integrated public transport
S
ISSN 0257 1978 Volume 36 No.6 s *ULY s R40.00 (incl VAT)
Units from Raubex Construction’s Cat earthmoving fleet deployed on Section 19 of National Route 12.
Water and wastewater 17 Rooiwal WWTW upgrade 23 Running on (near) empty 33 Basic services for informal 34 36 37 38
settlements Unlocking the potential of anaerobic digestion Gaborone sewerage system upgrade Counting every drop of water Zeekoegat WWTW extension
Industry news 39 Event listings and appointments
Pumps, pipes and valves 53 A new range of pumps 55 Giant sludge presses 57 Investing in infrastructure 58 SA Engineers go green 59 Fashionable concrete
Aging infrastructure 60 Population growth and aging infrastructure
63 Geared up to reduce water losses
IMIESA JULY 2011 - 1
AQUA DIRT TRAP/STRAINER Patent No. RSA 95/9706 Unit 2, Zone 5, Murrayfield, 4 Prospecton Road, 4115 . P.O. Box 357, Umbogintwini, 4120 Tel: +27 (0)31-902 6550 Fax: +27 (0)31-902 1349 Email: 0794949628@vodamail.co.za
Web address: www.aquastrainer.com MAKE THE INTELLIGENT CHOICE Install before every water meter and every pressure relief valve (PRV) The Aqua Dirt Trap/Strainer was designed for the protection of turbine-type flow meters and pressure relief valves. In order to eliminate the issue of damage and blockages, the Aqua Strainer was developed using mild steel pipes and flanges. The main feature of this strainer is the sight glass, situated on the top flange. The sight glass enables one to see directly into the pipeline. Blockages can be identified by merely looking into the sight glass. Consequently, the water flow can be observed and monitored. Blockages can be observed and removed by simply unbolting the top flange and cleaning the stainless steel grid, thereby reducing the downtime and make troubleshooting and fault finding, easier.
x x x
The Aqua Strainer is used and stocked at several Municipalities and water authorities. The water departments have specified the Aqua Strainer for all its projects and installations. The Strainer/Dirt Trap is an essential protection for all water meters in order for it to operate efficiently.
A TYPICAL INSTALLATION ESSENTIAL PROTECTION FOR ALL WATER METERS AND PRESSURE RELIEF VALVES.
COMMENT PRESIDENT'S COMMENT
PUBLISHER Elizabeth Shorten EDITOR Richard Jansen van Vuuren CREATIVE CHIEF EXECUTIVE Frédérick Danton SENIOR DESIGNER Hayley Mendelow SUB-EDITOR Danielle Hugo CONTRIBUTORS Minister of water and environmental affairs, Edna Molewa, Hennie Erwee, Tony Stone, Claire Lipsett, Candice Landie PRODUCTION MANAGER Antois-Leigh Botma PRODUCTION COORDINATOR Jaqueline Modise FINANCIAL MANAGER Andrew Lobban (ACIS, FCIBM) ADMINISTRATION Tonya Hebenton DISTRIBUTION MANAGER Nomsa Masina DISTRIBUTION COORDINATOR Asha Pursotham SUBSCRIPTION SALES Cindy Cloete PRINTERS United Litho Johannesburg +27 (0)11 402 0571 ___________________________________________________
The 75th IMESA Conference and jubilee-year celebrations WITH MID-WINTER and the first half of 2011 behind us, we can look forward to an exciting second half of the year and, in particular, the IMESA 75th Conference and jubilee-year celebrations. On behalf of the IMESA Exco, I would like to extend a warm welcome to everyone attending the 2011 IMESA Conference. Gavin Clunnie and the northern provinces branch, who are hosting this year’s event, have been hard at work over the past twelve months. Approximately 700 municipal councillors and engineering officials, engineering consultants, suppliers, service providers and delegates from all spheres of government are expected to attend. The theme for 2011 is a very appropriate one: ‘Yesterday, Today and Tomorrow’. IMESA will be looking back at the achievements of the past, marking this moment in time at the conference and then looking forward to the to the future of municipal engineering in Southern Africa. There will also be a number of special events arranged around the theme. The conference programme consists of eight sessions: Session 1: Welcome and keynotes Session 2: Transportation and traffic engineering Session 3: Sanitation Session 4: Storm water management Session 5: Roads Session 6: Water engineering Session 7: Environmental engineering Session 8: Financial aspects of providing services In addition to a full and varied conference programme, there will be many opportunities
ADVERTISING SALES Jenny Miller Tel: +27 (0)11 467 6223 ___________________________________________________
PUBLISHER: MEDIA No. 4, 5th Avenue, Rivonia 2056 PO Box 92026, Norwood 2117 Tel: +27 (0)11 233 2600 Fax: +27 (0)11 234 7274/5 E-mail: richard@3smedia.co.za www.3smedia.co.za ANNUAL SUBSCRIPTION: R440.00 (INCL VAT) ISSN 0257 1978 IMIESA, Inst.MUNIC. ENG. S. AFR. © Copyright 2011. All rights reserved. ___________________________________________________ IMESA CONTACTS IMESA Administration Officer: Ingrid Botton P O Box 2190, Westville, 3630 Tel: +27 (0)31 266 3263 Fax: +27 (0)31 266 5094 Email: imesa@webstorm.co.za Website: www.imesa.org.za BORDER BRANCH Secretary: Melanie Matroos Tel: +27 (0)43 705 2401 Fax: +27 (0)43 743 5266 E-mail: melaniem@buffalocity.gov.za EAST CAPE BRANCH Elsabé Koen Tel: +27 (0)41 505 8005 Fax: +27 (0)41 581 2300 E-mail: elsabek@africoast.com KWAZULU-NATAL BRANCH Secretary: Rita Zaayman Tel: +27(0)31 311 6382 NORTHERN PROVINCE BRANCH Secretary: Cornel Taljaard Tel: +27 (0)82 899 8341 Fax: +27 (0)11 675 1324 E-mail: cornel@rchc.co.za SOUTHERN CAPE KAROO BRANCH Secretary: Henrietta Oliver Tel: +27(0)79 390 7536 Fax: 086 536 3725 E-mail: imesa.southcape@gmail.com WESTERN CAPE BRANCH Secretary: Erica van Jaarsveld Tel: +27 (0)21 938 8455 Fax: +27 (0)21 938 8457 E-mail: erica.van_jaarsveld@capetown.gov.za FREE STATE AND NORTHERN CAPE BRANCH Secretary: Wilma Van Der Walt Tel: +27(0)83 457 4362 Fax: 086 628 0468 E-mail: imesa.fsnc@gmail.com
IME te te t i tuuute ti nsti ns h IInstit he f icc a fr rrnn AAfrica ern inn e of tthe ine hern a zine u he o ut a az ag South maga n g ooff SSo f fii cii all m e rrii ng ooffici of eeerin eeri inn ee h e offi The TTh ngg inee i p aall EEngin ip icccipal uunn icip Muni o M of
4HE OFFICIAL MAGAZINE OF THE )NSTITUTE OF -UNICIPAL %NGINEERING OF 3OUTHERN !FRICA
IMESA
MEDIA
INFR ASTR
UCT URE
DEV ELO
PME NT
• MAI NTE
DEL IVER ERV ICE • SERV NAN CE
Y
period of IMESA’s history. I look forward to seeing you at the conference!
INFRASTRUCTURE DEVELOPMENT ͻ MAINTENANCE ͻ SERVICE DELIVERY
Cover opportunity C
REST OF SOUTHERN AFRICA Representative: Andre Muller E-mail: imesa@webstorm.co.za
All material herein IMIESA is copyright protected and may not be reproduced either in whole or in part without the prior written permission of the publisher. The views of contributors do not necessarily reflect those of the Institute of Municipal Engineering of Southern Africa or the publishers.
for informal networking; a technical tour of the Gautrain (including a ride from Rhodesfield Station into Sandton) and a golf day. The organising committee has also compiled a special companions’ programme for delegate partners. Please place the following date in your diaries now: 26 to 28 October 2011 (the Birchwood Hotel and OR Tambo Conference Centre, Boksburg, Johannesburg). For further information, consult the conference website at http://www.conference.imesa.org.za. Also being celebrated this year is the 50-year jubilee of the inauguration of IMESA. The UK-based Institution of Municipal Engineers established an African District in 1905 and, for 50 years, the local chapter has continued to support municipal engineering in South Africa. During the late 1950s, preparations were made for the founding of a separate, independent and autonomous body to serve and protect the interests of municipal engineers throughout Southern Africa. The Institution (later changed to ‘Institute’) of Municipal Engineering of Southern Africa was formally inaugurated in May 1961. Professor Johannes Haarhoff has written a comprehensive history of IMESA. He provides a fascinating narrative on the growth of IMESA, from the time of its inception to what it has become today: a strong voice for municipal engineering in South Africa. This very special coffee table book, entitled Reflections, will be launched at the IMESA 2011 Conference. We will be inviting all past presidents of IMESA to the mayoral function at the IMESA Conference for a special celebration of what IMESA has achieved in the last 50 years. I am indeed honoured to be president during this
TER SBS WTAEMS reservoirs SYS Water DWA
BARLOWORLD EQUIPMENT
ni Blue and p Green Dro ni pality munici eThekwini 2 0 1 1 • grant for • May
Ekurhule
IMESA
ure Infrastructent managem
lion
R200 mil
CDM project
me 78 Volu 257 19 ISSN 0
5 36 No.
CAT reclaimer spearheads road upgrade
Kimberley
Mossel Bay
WWTW upgrade
Desalination
72 p Another link for integrated public transport
Working together
S
In each issue, IMIESA offers advertisers the opportunity to get to the front of the line by placing a company, product or service on the front fr ccover of the journal. Buying this position will afford the advertiser the ccover story on pages 4 and 5 and maximum exposure. For more informatition on cover bookings contact Jenny Miller on tel: +27 (0)11 467 6223.
ISSN 0257 1978 Volume 36 No.6 s *ULY s R40.00 (incl VAT)
IMIESA JULY 2011 - 3
ADVERTORIAL
Silulumanzi and Siza Water have rebranded THE NELSPRUIT CONCESSION COMPANY, Silulumanzi, changed its name to Sembcorp Silulumanzi, while its sister company in Ballito, KwaZulu-Natal, changed to Sembcorp Siza Water. This change came about as a result of the acquisition of the holding company by Sembcorp Industries. Sembcorp Industries is a company established in 1998 in Singapore and operates in 19 countries, across six continents, providing essential energy and water solutions to both industrial and municipal customers. Sembcorp Industries is also a world leader in marine and offshore engineering, as well as an established developer of integrated
Sembcorp Silulumanzi and Sembcorp Siza Water are proud of their increased capacity to provide customers with the best water supply and sanitation services, and have been awarded Blue and Green Drop status by the Department Of Water and Environment. With such a capable and committed shareholder, Sembcorp Silulumanzi and Sembcorp Siza Water have access to global best practice advice and resources that will, ultimately, benefit their customers in Mbombela.
townships and industrial parks. A provider of innovative solutions for clean and sustainable water, Sembcorp manages facilities capable of producing and treating over six million cubic metres of water and wastewater daily and serves close to five million people worldwide through its staff compliment of over 8 500 people.
operation, 91 km of new water mains were laid, as well as 18 km of sewers. At the same time, thousands of unregistered connections were found and many household and mains leaks repaired. This was repeated in 2010 in KaNyamazane, where household leaks, including toilet cisterns, were repaired or replaced. This has substantially reduced wastage and related savings have enabled delivery of services to areas not previously supplied. Today it manages 989 km of water mains and 582 km of sewer mains. Over six million litres of water per day have been saved to date; over 8 000 broken meters replaced and a further 15 000 new meters installed to provide new household connections and formalise existing unauthorised supplies. A new six million litres per day sewage treatment works has been built in Matsulu, replacing the old ‘pond’ system at a cost of
Sembcorp Industries is: • Owner and operator of the world’s largest operating hybrid desalination plant. • Developer, owner and operator of one of the world’s largest water reclamation plants. • Developer, owner and operator of China’s first facility treating high concentration industrial wastewater without the pre-treatment required by customers. What does this mean for the concessions?
4 - IMIESA JULY 2011
Our first ten years In 2009, Sembcorp Silulumanzi celebrated its 10th anniversary. In the first two years of
R8.3 million. The existing sewage treatment works at KaNyamazane have been refurbished at a cost of R3.3 million. The water supply to Matsulu West has been changed from a ‘chlorinated river supply’ to a fully treated potable supply. The concession has created permanent jobs and employee numbers have risen from 158 250. The capital works has also created just over 1 250 temporary jobs. Today a population of 390 000 in 73 600 households is served. Services are continually being rolled out and improved for, most especially, previously disadvantaged areas. In this regard, Sembcorp Silulumanzi con-
tinues to assist the municipality to implement its municipal infrastructure grant projects, as well as the bulk infrastructure for the new stadium. Affordability The concession agreement is structured to ensure Sembcorp Silulumanzi delivers quality services at an affordable price. Benchmarking with other municipalities is regularly conducted and, in a recent survey, Sembcorp Silulumanzi’s combined water and sewage tariffs, for a usage of 15 kl per month, were confirmed to be equal to the average of the cities surveyed.
EDITOR'S COMMENT
www.maritimejournal.com
The hangover is over
ABOVE The conversion of the Durban International Airport into a dugout port could be complete by 2019. Authorities are currently investigating ways in which the existing port could be linked to the new one
T
HE CONSTRUCTION ‘HANGOVER’ experienced after the heady days of the infrastructure boom leading up to Soccer World Cup has lasted for a long time. Government is being criticised from all quarters about the lack of projects being made available in the public sector. The construction industr y has now also raised concerns about government’s lofty ambition to develop 30 000 artisans within the next three-and-a-half years. Chris Campbell, president of the Engineering Council of South Africa (ECSA), says that, while the organisation acknowledges the need for more engineering practitioners, how the industr y will retain those practitioners when current appointees are being displaced due to diminishing contracts is a cause for concern. He has been quoted as stating that: “Constraint in activity does not resonate well with the need to respond to ser vice-deliver y challenges associated with waste-water treatment works that need recapitalisation and refurbishment, the upgrading of provincial and municipal road networks, the construction of decent amenities and the need
to build more schools, houses and other amenities.” Employment in the industr y is reported to have decreased from 175 000 in 2005 to 120 000 in 2011. Given this gloomy outlook, and the dire need for a mega-project to provide much needed work in the construction industr y, the news is that stakeholders are intent on ensuring a green light decision to convert the Durban International Airport into a dugout port by the end of July. The Depar tment of Transpor t would like to announce the R100 billion project at the African Renaissance Festival to be held in August this year. The event will, fittingly, be held in Durban. If all goes according to plan, the port could be operational by 2019, when it is expected that the current port will reach its capacity limit. This means that construction could be begin in 2015, allowing ample time to undertake the necessar y environmental impact assessments. It is estimated that as many as 60 000 jobs will be created through this massive undertaking. The first phase of the project, which may be
complete by 2019, will cost approximately R50 billion. The remainder of the project could be complete by 2037, with a running total expenditure of R100 billion. “This development is huge and will have an impact on South Africa for the next 15 to 20 years. The economy of the city (and the countr y) is dependent on building the capacity of the port,” states eThekwini municipal manager, Michael Sutcliffe. Other developments to be linked to the construction of the new port include a dr y port at Cato Ridge and an improved rail network system. The IMIESA team has a busy few months ahead. We will be attending several industr y events and conferences in the coming weeks. Attendance at these is crucial for us as we get to know our readership on a personal level and gain access to information that assists us in compiling a magazine that contains informative business intelligence, product technology and project news. Our September edition will include features on water, waste water and desalination, as well as trenchless technology. If you would like to share any news on projects and technologies within these fields, please feel to contact us.
Richard Jansen van Vuuren, editor of IMIESA
IMIESA JULY 2011 - 5
COVER STORY
A new super-class highway Raubex Construction’s new Cat RM500 rotary mixer forms the backbone of the road reclamation and stabilisation works on Section 19 of the N12.
A
S PART OF AN EXTENSIVE motorway network measuring some 185 km, the ongoing Gauteng Freeway Improvement Project (GFIP) is creating a modern, world-class toll route system that provides major impetus to socio-economic growth in South Africa’s most populous and commercially active region. Being implemented in stages by the South African National Roads Agency Limited (SANRAL), these routes radiate outwards from Johannesburg and Pretoria’s industrial and residential centres to all points of the compass. With major N1 and N3 transportation upgrades within Gauteng, free-flowing
traffic has already replaced previous congestion, which is driven foremost by business priorities that are time dependant – as are the ensuing construction works. National Route 12 (N12) is one of SANRAL’s strategic priorities and it is here that civil engineering contractor, Raubex Construction, has been awarded the task of implementing a complete overhaul on Section 19. The scope of works involves an intensive programme running over 30 months. Three major new interchanges, successive bridge widenings and an east- and westbound three-lane highway in either direction will replace the existing N12 dual carriageway
BELOW A new east- and westbound three-lane highway will replace the existing N12 dual carriageway system along approximately 10 km between the current Tom Jones and Daveyton on- and off-ramps
system along approximately 10 km between the current Tom Jones and Daveyton onand off-ramps. The median reserve will be replaced by a central concrete median barrier to make room for the new lanes, and this is where the roadworks begin, moving progressively from the inside out to complete the new freeway system. This is the main access point passing into and out of Gauteng’s West Rand region to the agricultural and mining heartland of Mpumalanga, and managing high traffic densities, together with major road realignments, will be just one of a number of challenges. The N12 design calls for an emulsion and cement stabilisation mix for the sub-base layers. “The N12 contract follows a similar pattern to the SANRAL project we completed in May 2010 for Section 1 of the R21 upgrade, which
COVER STORY links OR Tambo International Airport with Pretoria,” explains Raubex Construction operations manager, Wouter van der Mer we. (Raubex Construction is a division of JSE-listed entity Raubex Limited.) Works on the R21, which used cement as the stabilisation medium, began at the Olifantsfontein Interchange (km 27.60) and ended at the Hans Strijdom Interchange (km 45.30), with all phases completed within 27 months. “What makes the N12 project particularly noteworthy is that all materials will be worked in situ or sourced from cuttings that will make way for the new lanes and interchanges along the route. Achieving this requires ver y complex planning to meet incremental time frames,” explains Van der Mer we. In total, approximately 74 ear thmoving machines will be deployed on the N12 site, a high percentage of which are Cat machines, supplied and supported by Southern African Caterpillar dealer, Barloworld Equipment. For both the existing and new lanes, full depth reclamation and soil stabilisation will be carried out by Raubex’s recently acquired Cat RM500 rotar y mixer. Although this is Raubex’s first RM500 unit, the company owns and has gained considerable experience with the smaller-sized RM300, one of which was used on the R21 project. As Barloworld Equipment product manager Johan Hartman explains, the Cat RM500 has an operating weight of 28 145 kg and is driven by a Cat C15 ACERT engine, generating a gross power output of 403 kW. This compares with the Cat RM300’s operating weight of 24 454 kg and gross power deliver y of 261 kW via its Cat C11 engine. “Width of cut on both models is the same, at 2 438 mm, while the maximum depth of cut is 457 mm,” he adds. Dual pump system Unlike the RM300 unit, which has a single water pump for optimum moisture content deliver y, the RM500’s design incorporates both a water and an emulsion pump that are simultaneously monitored in the cab via two separate flow meters. “We needed a higher power-to-weight ratio on the N12 to cope with the existing varied in situ premix materials; plus, the dual-mix stabilisation design makes the RM500 the optimal choice,” continues Wouter. This will be a construction road train,
ABOVE For both the existing and new lanes, full depth reclamation and soil stabilisation will -be carried out by Raubex’s recently acquired Cat RM500 rotary mixer
with the RM500 pushing ahead two tankers, one carr ying 18 000 ℓ of emulsion and the other 18 000 ℓ of water for the subbase phase. The emulsion ratio will be between 2 and 3%, and the cement around 1.5 to 2%. The RM500’s water spray pump system has two flow-rate ranges, extending from 114 to 1 836 ℓ/min, with the emulsion spray pump system operating at predetermined volumes of 114 to 757 ℓ/min. With the RM500, Raubex will reclaim and stabilise the 300 mm sub-base in one go along the demarcated sections. The equipment on the ETB section will comprise the Cat RM500, in addition to a Cat fleet that includes the latest-generation Cat 140K motor grader, as well as Cat CS76 single-drum, 20 t vibrator y rollers. For the 300 mm sub-base layer, the RM500’s universal rotor – equipped with its 200 carbide-tipped bits arranged in a chevron pattern – comes into play in reworking these dense in situ materials, providing the highest level of material pulverisation and gradation. A three-position mode switch enables the rotor depth to be controlled manually or automatically to a preset cutting depth, to ensure that the engineering design is precisely met. The RM500’s mixing chamber features a heavy-duty hood with a large volume capacity to handle deep mixing. This ensures exact depth control, proper sizing and thorough blending of reclaimed materials. From a quantity perspective, the volumes on Section 19 are substantial. Raubex’s
RM500 will be deployed for the sub-base component, amounting to 135 000 m3, while the selected 300 mm layer comprises some 102 000 m3. Additionally, the new highway construction will require some 9 million litres of emulsion, 5 000 t of cement, 114 000 t of BTB, and also 530 000 m2 of 35 mm AE2 asphalt premix and the equivalent for the 18 mm ultra-thin friction course (UTFC) overlay for the final riding sur face. Blacktopping will be carried out by Raubex Limited division Roadmac Sur facing. “Logistical planning is the key, as is the optimal deployment and utilisation of our earthmoving fleet, and in this respect one of the features we particularly like about the RM500 is its flexibility and all-round viewpoints to the front and rear,” says Van der Mer we. “The ability to hydraulically shift the entire cab from side to side, for example, really speeds up the work rate as there is no need to plan in half-widths, plus the mix is always visible from the operator station.” This full-width, side-to-side feature enables the operator to work up and down specific stabilisation sections without having to reverse back to the starting point of the works, maximising on-site productivity. “Efficient use of materials and machines will be interdependent on this contract and we have invested in the best possible technologies to meet our completion targets as we steadily transform Section 19 into a multi-lane, world-class highway,” adds Van der Mer we.
IMIESA JULY 2011 - 7
ABS Afri-Infra AJ Broom Arup SA Aurecon Bigen Group Africa BKS Consulting Engineers BVI Consulting Engineers CBI Consulting Engineers Civil & Blasting Solutions Concrete Manufacturers CSIR Built Environment Davies Lynn & Partners Development Bank of SA DPI Plastics EFG Engineers Elster Kent Metering EnviroServ Waste Management Geotechnologies GLS Consulting Goba Hidrostal SA Huber Technology Hydro-comp Enterprises I@Consulting Iliso Consulting Infraset Jeffares and Green Johannesburg Water Kgatelopele Consulting
hennie.basson@absgroup.com afri-infra@mweb.co.za ajbroom@icon.co.za rob.lamb@arup.com Ian.VanWijk@af.aurecongroup.com kevin.barnett@bigenafrica.com siyandan@bks.co.za cask@bvigp.co.za durban@cbisa.co.za jane@drillingandblasting.co.za cma@mweb.co.za LAustin@csir.co.za dlpdbn@dlp.co.za divb@dbsa.org.za mgoodchild@dpiplastics.co.za eric@efgeng.co.za keith.bailey@za.elster.com benoitl@millenniumwaste.co.za garry@geotechnologies.co.za nicky@gls.co.za trumang@goba.co.za hstal@mweb.co.za fstammer@lantic.net dan@edams.co.za louis_icon@mics.co.za monde@iliso.com fmyburgh@infraset.com dennyc@jgi.co.za rtaljaard@jwater.co.za kgatelopele@wol.co.za
Knowledge Base KV3 Engineers Lektratek Water Makhaotse Narasimulu & Associates Maragela Consulting Engineers Much Asphalt Bosch Munitech (Pty) Ltd Nyeleti Consulting Odour Engineering Systems Power Construction Pragma Africa Rocla SBS Water Systems Sektor Consulting Sight Lines Pipe Survery Services SNA Inc Siza Water Company SRK Consulting SSI Bosch Stemele (Pty) Ltd Syntell Thm Engineers East London TPA Consulting UWP Consulting Vela VKE WSP Group Africa WSSA WRP Zebra Surfacing
info@knowbase.co.za cbrandsen@kv3.co.za general@lwt.co.za mmakhaotse@mna-sa.co.za admin@maragelaconsulting.co.za john.onraet@murrob.com munitech@iafrica.com ppienaar@nyeleti.co.za mathewc@oes.co.za nbarnard@powergrp.co.za deang@pragma.co.za karen.devos@murrob.co.za irene@sbsgroup.co.za cradock@sektor.co.za sales@sightlines.co.za snapta@icon.co.za tionette.bates@sizawater.co.za jomar@srk.co.za francisg@ssi.co.za TurnerS@sbadbn.co.za julia@syntell.co.za thmel@mweb.co.za roger@tpa.co.za zulchl@uwp.co.za capetown@velavke.co.za dirk.hattingh@mbs-wsp.co.za nbinase@wssa.co.za ronniem@wrp.co.za andrew@zebrasurfacing.co.za
GOVERNMENT PERSPECTIVE
Working together for economic growth The Department of Water Affairs intends to contribute to the national effort to build a more equitable society by focussing on the creation of sustainable job opportunities. Minister of water and environmental affairs, Edna Molewa
G
UIDED BY THIS VISION, the Department of Water Affairs (DWA) will work together with the people of South Africa to make more water available for economic growth and the creation of decent jobs.
10 - IMIESA JULY 2011
Water scarcity will limit the potential for economic growth The countr y is facing challenges associated with freshwater scarcity, which is exacerbated by growing demand, pollution of
GOVERNMENT PERSPECTIVE Minister of water and environmental affairs, Edna Molewa
water sources, wastage and unsustainable usage. We have no option but to change our behaviour and attitude towards water use as part of our ongoing endeavour to build sustainable livelihoods for the people of our countr y. Indeed, if we do not change the way we use our water resources, our ability to meet the objectives of The New Growth Path, key among them being the creation of decent work, will be compromised. Without water, we will struggle to meet the energy generation capacity we need for economic growth. Without water, the agricultural sector’s ability to create jobs and provide food security for our countr y will be severely curtailed. Mines and factories that must contribute to economic growth and employment creation will not sur vive. We therefore have a collective responsibility to proactively protect our water resources, prevent them from being contaminated and use them more efficiently.
Kerbs Dry-casting means no exposed aggregate or blowholes on the surface of our kerbs.
Building and maintaining adequate water infrastructure One of the imperatives for economic growth and job creation is infrastructure development. In this regard, we are proud of the work we are doing to improve water infrastructure in our countr y. The Trans-Caledon Tunnel Authority has procured funding in order to implement the Mokolo and Crocodile River (West) water augmentation project, phases 1 and 2, at a total cost of approximately R2 billion. This will assist in delivering water to Eskom’s new Medupi power station and other industries in the area, as well as domestic water to the Lephalale local municipality. About 75% of this phase will be funded by off-budget sources, while the remainder will come from our budget. We expect the first water deliver y in 2014. In KwaZulu-Natal, on the Mooi River near Rosetta, we have already awarded a R2.2 billion contract for the construction of the 42 m-high Spring Grove Dam, with a storage capacity of 142 million m3. Work will commence shortly and we expect the first water deliver y in November next year. We will also be spending R91.2 million in this financial year to upgrade the Hazelmere Dam in order to augment the water supply to Umgeni Water for treatment and supply purposes along the KwaZulu-Natal north coast in the areas of Mdloti to Thukela. The construction of the De Hoop Dam and its associated water distribution for domestic and agricultural use in the Greater Sekhukhune, Waterberg and Capricorn District Municipalities is on course. The estimated cost for completing the construction of the De Hoop Dam, which began in 2007, is approximately R3.1 billion. R2.1 billion has been spent for the 2010/11 financial year and R926 million will be spent over the next three years. The distribution network will be constructed in conjunction with the completion
At Bosun, our approach to resolving engineering challenges has always been to simplify and innovate. That’s why we’ve taken the manufacturing of kerbs further with our revolutionary dry-casting process. This allows us to compact the kerb, making a stronger, more durable end product. And, making kerbs the Bosun way is kinder to the environment. No acids and chemicals are needed as mould release agents. Another great reason to specify Bosun kerbs on your next civil engineering project. Visit www.bosun.co.za for even more ideas.
Gauteng Tel (011) 310-1176 bosunmidrand@bosun.co.za Eastern Cape Tel (041) 405-0100 bosunpe@bosun.co.za
E+I 15128
IMIESA JULY 2011 - 11
The only SABS-approved dry-cast kerb in SA.
North West Province Tel (012) 250-1711 bosunbrits@bosun.co.za
GOVERNMENT PERSPECTIVE of the dam. This will deliver water to a total of 3 million Limpopo residents for domestic-use purposes. During this financial year, we will commission the construction of a water conveyance system from the Vaal Dam to Secunda in order to augment the water supply to Eskom power stations and Sasol. This comprises abstraction works, storage reser voir, high lift pump station and a 121 km pipeline. In addition to the infrastructure development that is currently under way, we are also finalising planning and preparations for the construction of other dams and related infrastructure. These include the completion of water treatment works and a bulk distribution system from Nandoni Dam in Limpopo, the construction of a pipeline from the Flag Boshielo Dam to Mokopane and nearby communities, the completion of feasibility studies and designs for the Umzinvubu and Foxwood Dams in the Eastern Cape, the construction of the bulk distribution pipelines and reticulation networks from the Jozini Dam in KwaZulu-Natal, Groot Letaba Augmentation project (consisting of the raising of the Tzaneen Dam), the finalisation of plans for the construction of the N’wamitwa Dam and associated water treatment plants and bulk distribution pipelines. We are well advanced with the negotiations for a joint agreement with the government of Lesotho for the implementation of the second phase of the Lesotho Highlands water project, which will augment the Vaal River system that supplies water to Gauteng and surrounding areas. This is scheduled for completion in 2020. Water security and security of supply South Africa is, arguably, a water-scarce countr y. It has a low rainfall and experiences one of the lowest run-off rates in the world. I must emphasise that this phenomenon is not unique to South Africa, it is a global issue. Some prophets of doom have given out the wrong message and warned that Gauteng will run out water by the year 2013, while others say in 2025. What is interesting is that there is no agreement among them on this issue. As the minister responsible for water, I want to assure South African citizens that, if we manage our resources well and use water judiciously, there is no imminent shortage of water. Our current projections are that South Africa will, in all probability, exceed the limits of its economically useable land-based water
A schematic view of the Sedgefield desalination plant, showing seawater intake (purple), brine outfall (red) and distribution (blue) networks
resources by 2050, but my department is working on innovative measures to ensure that there will be clean water for human consumption for future generations. We admit that there are real and significant challenges with regard to water management in our countr y and this is why we have begun to think creatively about different ways of preser ving and protecting this precious resource. Factors such as climate change and increasing population growth lead to an increase in water consumption and continue to be a challenge. Education of the general public on water conser vation continues to be an imperative. We have thus begun with campaigns aimed at raising awareness about water conser vation and encouraging our communities to become leaders of a movement that will wage war against water wastage. We have also begun engaging in the task of desalinating sea water. We have already started this work in the Western Cape and we intend bringing it to other coastal towns to augment the water
12 - IMIESA JULY 2011
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GOVERNMENT PERSPECTIVE supply for domestic use. In December 2009, we completed a desalination plant in Sedgefield and in June last year we completed a waste water recycling facility in George. We have already secured water supply for the Eden District through desalinated water from the Mossel Bay, Sedgefield and Bitou plants.
If we manage our resources and use water judiciously, there is no imminent shortage of water Groundwater remains a ver y important source of water which we have not fully exploited as a countr y. I am pleased to announce that we have already started to implement a strategy aimed at exploiting our underground water resources. Elements of this strategy include training and support for municipalities with groundwater management tools, publishing of the National Groundwater Archive and giving support to municipalities in terms of the implementation of artificial recharge, where feasible, to secure water for later use. We intend to focus on monitoring groundwater resources, especially acid mine drainage, trans-boundar y aquifer systems, climate variability and municipality systems. Support of local government is key We will continue to work with local government to assist them in dealing with challenges related to water provision. The bulk infrastructure we alluded to, which is provided by the Department of Water Affairs, needs to be integrated with water infrastructures provided by the water ser vices authorities
The seawater intake and brine outfall at the Mossel Bay desalination plant
IMIESA JULY 2011 - 13
GOVERNMENT PERSPECTIVE (municipalities) working under COGTA. The water ser vices authorities have been experiencing difficulties in linking reticulation infrastructure to bulk infrastructures (dams). This challenge has, in many instances, left communities without water for household consumption whilst the pipelines pass though such communities. In reviewing this practice, which had unintended consequences, we have adopted a new approach to water provision with the concomitant infrastructure from ‘source to tap’. This requires joint planning and execution similar to the one we applied during the FIFA World Cup. This we will do to give practical meaning to our commitment to cooperative governance across all spheres of government. Specifically, we will continue to work with municipalities to address challenges such as effluent discharges into rivers and streams, aging water infrastructure at municipal level, the state of waste water treatment works and skills development. Risk-based regulation was augmented by a global first innovation to develop a Wastewater Risk Abatement Planning (W2RAP) process, which is currently being peer reviewed by the Water Research Commission and will be rolled out as soon as the peer review is completed. This will create a new pre-emptive paradigm for waste water ser vice management. We are currently using this system within the Hartbeespoort Dam catchment area to ensure an improvement at source of the effluent being discharged into contributing tributaries. We are also grateful for the commitment of the municipal wastewater treatment management in the City of Johannesburg,
We will continue to work with municipalities to address challenges City of Tshwane, Ekurhuleni, Mogale City and Randfontein in improving wastewater processing through the introduction of the W2RAP process. In another important development, the cities of Cape Town and eThekwini adopted this process voluntarily once they saw the enormous benefit that such an approach will bring to their wastewater management approach. We also deployed the Emergency Response Facility (Rapid Response Facility,) as informed by the Green Drop regulator y processes. Going for ward, we will introduce new regulations for process controlling which incorporate mandator y training for all water and wastewater process controllers. This we will do with the objective of enhancing and professionalising water and waste water treatment skills. In line with our commitment to the principle of cooperative governance, we will, this year, adopt an integrated approach to water provision. In terms of this approach, we will work together with water services authorities in the metros, district and local municipalities to provide an unbroken chain of water supply from source to tap and ensure the sustainability of our water usage. We are doing all of these things to ensure that we increase the capacity of local government to deliver more quality water ser vices to more people.
14 - IMIESA JULY 2011
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Rooiwal WWTW upgrade An extensive upgrade of the Rooiwal Waste Water Treatment Works (WWTW) north of Pretoria is nearing completion. Richard Jansen van Vuuren spoke to the on-site project participants.
The Rooiwal WWTW receives sewage from the eastern, central and western areas of the City of Tshwane, with an organic loading exceeding 1 000 mg/l COD. “The purpose of the project was not to increase the capacity of the existing Rooiwal WWTW from the present 150 Ml/d, but to make modifications to the works to improve performance,” explains Lincoln Makombore, associate in the water division of SSI Engineers and Environmental Consultants. The elements of the project can be broken down as follows: • Feasibility study and report on all identified
• Construction. • Supervision of construction. • Commissioning of the plant.
issues. • Process design in co-operation with the City of Tshwane (CoT) for the selected work. • Conceptual design and positioning of a new power supply and units on the site. • Licence application in terms of the Water Act by CoT. • Preliminary and detailed engineering design. • Tender and contract documentation, and procedures for the construction of the works (including retrofitting of the existing plant).
Background to the project The WWTW consists of three areas or divisions – the first having been built in the 1950s and the most recent in 1983 – designed to treat a total flow of 245.33 Ml/d. The three areas are: • Rooiwal West: 40.8 Ml/d (biological trickling filter facility). • Rooiwal East: 54.5 Ml/d (biological trickling filter facility). • Rooiwal North: 150 Ml/d (biological nutrient removal (BNR) activated sludge plant. A number of main outfall sewers service the Rooiwal WWTW, from the eastern, central and
All images courtesy of Richard Jansen van Vuuren
RIGHT The large diameter pipe connecting the new balancing dam to the existing balancing dam BELOW A view of the earthworks at the 10 Mℓ attenuation pond site
IMIESA JULY 2011 - 17
WATER AND WASTE WATER western regions of CoT. The Rooiwal WWTW also has a sludge dewatering facility (SDF), which dewaters sludge from all three works. Rooiwal North Works currently treats an average daily dry weather flow (ADDWF) of 150 Mll/day, which is equal to its design capacity of 150 Mll/d. Two equal sized balancing tanks were constructed in 1995, comprising a total of 28 Mlof balancing capacity. The inlet works were designed for a peak wet weather flow (PWWF) of 540 Ml/d, i.e. 3.6 x ADDWF (with three screens). Raw sewage is currently screened by means of two rotary drum mechanical screens with screenings conveyor, screenings dewatering and compaction. Grit is removed in vortex de-gritters and mechanical grit classifiers. The sewage is divided into two channels. The one channel feeds primary clarifiers from where the flow is balanced by the balancing tanks (14 Ml) before biological reactors units. The other channel feeds primary clarifier 3, from where the flow is balanced by the balancing tank (14 A view of the gargantuan drying bed
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Head Of¿ce: Telephone (018) 293 0487 • Fax (018) 293 0489 • Web: www.lwt.co.za • e-mail: general@lwt.co.za Other branches: Western Cape (Parow), Eastern Cape (Port Elizabeth), Botswana (Gaborone)
WATER AND WASTE WATER RIGHT The existing aeration pond
Ml) before it goes to biological reactors. The settled primary sludge is collected and pumped to the anaerobic digesters. The settled sewage stream flows past the balancing tank draw-off point en route to the activated sludge reactors, with the peak flows, which are in excess of the design flow, pumped from a sump to the balancing tanks from where it is released under gravity during off-peak hours for treatment in the activated sludge reactors. The activated sludge reactors comprise anaerobic, anoxic and aerobic zones, with internal recirculation from the third aerobic zone to the beginning of the anoxic zone. Waste activate sludge (WAS) is withdrawn from the last aeration zone to the dissolved air flotation (DAF) unit and return activated sludge (RAS) is returned from the secondary clarifiers to the anaerobic zone. The clarified effluent from all the reactors is collected in a common BELOW The 14 Mâ„“ reinforced concrete balancing dam
IMIESA JULY 2011 - 19
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WATER AND WASTE WATER ground channel, where it is chlorinated and enters the chlorine contact channel which forms part of the maturation ponds. Part of the effluent gravitates to the Rooiwal Power Station for cooling water, and to the final effluent dam, from where it is pumped to supply irrigation water to adjacent farmers. Waste activated sludge (WAS) from all the reactors is thickened by means of DAF in two DAF tanks. The thickened sludge is further treated in the aerobic digester from where it is pumped directly to the sludge holding dam at the sludge dewatering facility. The sludge dewatering facility (SDF) receives anaerobic digested sludge from Rooiwal. The facility includes a 1.77 Ml sludge holding dam, which is aerated. The building houses 3 x 2.5 m-wide dewatering filter presses. The sludge cake is discharged to a sludge hopper, from where it loads tractor drawn sludge spreaders, which spread the sludge cake on the agricultural lands. The filtrate and wash water from the belt filter presses is dosed with ferric chloride (FeCl3) and pumped to Rooiwal Works where it is treated further. As the WWTW was not performing satisfactorily and the effluent did not comply with effluent standards at all times, the CoT appointed SSI engineers and environmental consultants to oversee the upgrade. Description of construction work Balancing dam: The construction of 14 Ml reinforced concrete balancing dam, including all earthworks, pipe work and the connection of a large diameter balancing pipe into the existing balancing dam. New inlet channel: The construction of a new reinforced concrete inlet channel around the existing inlet pipe; the construction of a new reinforced concrete sump and bypass pipeline to the existing sump; alterations to the existing pump station sump; the removal of existing pipeline and cutting through the existing channel wall without arresting the flow of the existing channel. New sludge drying bed: The construction of a new sludge drying bed; concrete slabs for stock pile facilities and a 10 Ml concrete lined contaminated storm water run-off attenuation pond. Pipelines: Peter Cremer from Eigenbau, the contractor appointed to the project, explains that all new piping is constructed with highdensity polyethylene (HDPE) in 600 mm, 400 mm, 350 mm and 300 mm diameters. “There was approximately 800 m of each diameter used, equating to a total length of
almost 3.2 km,” states Cremer. Eigenbau is also responsible for the construction of an attenuation dam below the newly 200 m X 200 m constructed drying bed. Instrumentation: “CT Control Systems was tasked to design and install the plant automation system for the WWTW,” explains Kuben Gopal from CT Control Systems. The company designed the control system hardware and software for the primary sedimentation, anaerobic digesters, aerobic digester, DAF sludge, sludge holding and balancing tank. The plant variables had to be communicated through wireless radio technologies. “We used ISONIC controllers for pump controls on the various tanks, which were then converted to Ethernet so as to ensure wireless communications on Mikrotik Ethernet radios. Schneider electric programmable logic controllers (PLC) and HMI were used as the main industrial plant control system,” continues Gopal.
Pipeline replacement underway (the pipelines at the bottom of the pit are newly installed)
Mechanical: The mechanical scope of the contract comprised the supply, installation and commissioning of a 2 m wide front rake screen and an additional 2.5 m Lektratek belt press, which was installed to assist the existing three Lektratek 2.5 m belt presses to handle the increased sludge loading. Equipment for the various pump stations, complete with pipe work, valves and submersible mixers, was also supplied by Lektratek Water Technology. Upgrading of Rooiwal WWTW project values Project cost estimate: R85 million Civil works R65 million Mechanical works R15 million Electrical works (MV & LV) R40 million Electronic works R1.2 million
IMIESA JULY 2011 - 21
WATER AND WASTE WATER
Running on (near) empty Running out of water is one of the harsh realities of an extended drought, as the Municipality of Mossel Bay recently experienced. A solution has, fortunately, been found. by Hennie Erwee and Tony Stone
T
HE CAPE COAST, from Plettenberg Bay to Mossel Bay, has, until recently, been in the grip of the worst drought in more than a century. With dams and other water resources reaching critical levels, this pristine stretch of coast was declared a disaster area. Mossel Bay, the hub of South Africa’s petrol from gas industry, its 117 840 residents and its annual influx of summer holiday tourists, which more than doubles the population, would have been in dire straits had the situation not been resolved. In particular, PetroSA, operating one of the
world’s largest gas-to-liquids (GTL) refineries and a strategic supplier of petroleum to South Africa, cannot just scale or shut down its production capacity without incurring costs (e.g. an estimated R10 m/day if shut down). Hence its participation in the project, which would provide it with a guaranteed supply of water and reduce the risk of it running out of the water required for the operation of its plant. Against the backdrop of the largely unknown, but speculated, effects of global warming, a decision was also made to concon sider other drastic and more innovative water
purification methods, such as waste water re-use and seawater desalination. With its back against the wall, Mossel Bay’s municipality approved the construction of an emergency seawater desalination plant to augment its traditional water supply from the fast-depleting Wolwedans Dam with the production of 15 Mℓ/day of treated seawater. 10 Mℓ/day was allocated to the municipal domestic supply and 5 Mℓ/day to PetroSA. The Mossel Bay Municipality, PetroSA and the Department of Water Affairs were thus Mossel Bay’s 15mℓ desalination plant
IMIESA JULY 2011 - 23
WATER AND WASTE WATER able to provide the necessary funding to build the plant. What is desalination? Desalination, in this instance, involves the process of taking raw water from the sea and subjecting it to a treatment process through which dissolved salts, suspended inorganic solids, dissolved and suspended organic matter and suspended micro-organisms are removed from the water to produce potable water, which conforms to the South African National Standard (SANS 241), that is safe for human consumption.
project manager to ensure that all sub-projects were closely monitored and coordinated. This included the construction of a marine seawater intake pipeline, a marine outflow brine discharge pipeline, a pump station and desalination plant comprising pre-treatment, reverse osmosis and posttreatment sections, as well as a workshop and administration offices. A summary of the project milestones and activities, as fast tracked, are provided in table 1: Overriding considerations In choosing a location for the desalination plant, various technical factors, such as sea water access, industrial zoned land and locality to PetroSA and Mossel Bay’s clear water pipeline system, were taken into consideration. After considering various alternatives, a portion of land in one corner of PetroSA’s Hartenbos tank farm, adjacent to Dias Beach, was chosen. However, because of its locality to petrol tanks, all designs and drawings were subjected to detailed hazardous
ABOVE Intake pipeline in 120 m sections laid out and ready for installation
operation (HAZOP) reviews. Due to time pressures, some mechanical and electrical equipment, imported from Europe, had to be delivered by airfreight to meet construction deadlines. Reverse osmosis desalination plant The desalination plant, designed, built and operated by Veolia Water Solutions BELOW Inside the intake pump station
FIGURE 1: Principal of reverse osmosis and semi-permeable membrane How it works The desalination process uses Mother Nature’s method of balancing water concentrations through a membrane, termed osmosis, but in reverse. This can also be called hyper filtration. Saltwater is passed, under pressure, through a semi-permeable membrane that keeps suspended, and most dissolved matter, on one side while allowing pure water to pass through to the other side. Ionized salts, colloids and organics above the 150 molecular weight threshold are disposed of while the potable water is collected. Project parameters Given the urgent need to establish a reliable, alternate water source, the desalination project was implemented under an accelerated programme, with the key objective being to commission the plant before Mossel Bay and its surrounds ran out of potable water. SSI was appointed overall TABLE 1: Project time line
TASK Proposals and procurement (consulting engineers appointed May 2010, tenders closed mid July 2010) Marine works (RLH and M&RM) Desalination plant (SSI and Veolia Water Solutions & Technologies South Africa (Pty) Ltd) Pipelines and civil work (MVD and Entsha Henra Construction) Power supply - electrical work (CVW and VE Reticulations) EIA and authorisations (Aurecon) Commission plant Handover (72 hour test run) Mossel Bay desalination plant Complete project, from consultant appointment to commissioning (16 May 2010 to 21 June 2011)
DURATION 40 days 120 days 180 days 120 days 60 days 120 days 30 days 3 days 401 days
IMIESA JULY 2011 - 25
WATER AND WASTE WATER & Technologies South Africa (Pty) Ltd, is a single pass reverse osmosis (RO) system consisting of six modular 2.5 Mâ„“/day RO units. The membranes used for reverse osmosis have a dense barrier layer in a polymer matrix where most separation occurs. In this case, the membrane is designed to allow only water to pass through, while preventing the passage of solutes and suspended materials. This process requires high pressure, in this instance approximately 63+ bar, to be exerted on the seawater side of the membrane, which has around a 27 bar natural osmotic pressure that must be overcome. The feed water abstraction and the disposal of concentrate (brine) is achieved by direct abstraction from the sea intake pipeline that is pumped by a seawater abstraction pump station to the desalination plant, with the final disposal of brine from a pipeline into a diffuser structure in the sea. Intake system The quantity of water required, based on the 15 Mâ„“/day of potable water needed, was derived from an anticipated har vest of 40% of the intake flow. The total volume intake per day was thus computed at 15 divided by 0.4, which gives 37.5 Mâ„“/day. Operating with three intake pumps to allow for modularisation, each pump was required to deliver a minimum volume of 595 m3 of seawater per hour. This rate dictated that the sea water intake pipeline, The dual media filters
WATER AND WASTE WATER LEFT Racks of RO pressure vessels
standard used for sea life. The intake structure comprises three vertical intake towers abstracting water between 2.0 m and 3.0 m above the seabed. The multiple intake towers help to dissipate the vacuum effect caused by the suction of water up the pipelines. To further limit the potential uptake of marine organisms, the opening of the intake towers are equipped with a 20 mm diameter screen and seawater is abstracted horizontally from the water column to minimize impingement of smaller and weaker marine swimmers.
running 725 m beyond the high water mark into the sea, and 880 m in overall length, be constructed from a 900 mm diameter pipe. HDPE, with a wall thickness of 60 mm, and noted for its corrosion resistance, was selected. The pipelines were butt welded in 120 m strings, from 12 m sections in a pipe assembly yard, with flanges at both ends. The intake structure was designed with a maximum intake velocity of less than 0.15 m/s, which is the minimum escape velocity RIGHT The backwash tank IMIESA JULY 2011 - 27
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SENIOR CIVIL ENGINEER: STORMWATER & COASTAL ENGINEERING TCOE: R440 129 – R664 912 p.a. • Ref. TRAMP 47/11 Requirements: Degree in Civil Engineering (B.Sc/B.Tech) • at least five years’ appropriate experience with a strong computational hydraulics focus • a valid Code EB driver’s licence. Key Performance Areas: Developing and maintaining the hydrological and hydraulic computer modelling capabilities of the Roads & Stormwater Department, including responsibility for the City’s Metro-wide stormwater master planning models • maintaining compliance with National Dam Safety Regulations for the City’s stormwater dams • managing the engineering aspects of the City’s coastal amenities and infrastructure • providing specialist input into the implementation of catchment and stormwater management strategies and policies • managing hydrological monitoring datasets and analysis of data. Note: Salary offer excludes the Cost of Living increase effective 1 July 2011. Please forward a comprehensive CV and covering letter, including a certified copy of your Identity Document to TransportRoads.Stormwater@ capetown.gov.za or to the Department of Strategic Human Resources, P.O. Box 298, Cape Town 8000. Kindly note that applications will not be acknowledged in writing and that copies of supporting documents will not be returned. Please quote the reference number of the vacancy in all communications. Certified copies of qualifications must be available on request. Visit our website at www.capetown.gov.za/careers Closing Date: 12 August 2011 No late applications will be considered. If no notification of appointment is received within two months of the closing date, please accept that your application was unsuccessful. 100961
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The electricity and electronics control room
A chlorine dosing line is attached to the intake pipeline and will dose the intake water just inside the intake structure to prevent algal and other marine organisms from growing inside and clogging up the intake pipeline. Pre-treatment The objective of pre-treatment is to prevent membrane fouling. An accumulation of one or more foreign substances on the sur face of a membrane will result in a loss of flux (the rate of flow through the membrane material). Higher operating pressures will then be required to maintain water production and quality, resulting in higher energy consumption. The pre-treatment in the plant consists of chemical dosing (when required) and sand filtration. The addition of sulphuric acid to seawater ser ves to correct its pH from around 8.0 to between 6.8 and 7.2. Ferric chloride causes suspended solids in the seawater to
28 - IMIESA JULY 2011
bind together, forming flocs, which will then settle out of suspension or be removed by filters with greater efficacy. The plant employs a dual stage filtration methodology, where intake water from the seawater buffer tank is passed through a series of pressurised horizontal down-flow sand or media filters to remove coarser organic impurities and sediments from the seawater. The first stage filters remove approximately 95% of solid contaminants. The filters are backwashed approximately once in ever y 24-hour operational cycle and the backwash filtrate is pumped to the brine buffer tank for mixing and disposal via the brine disposal system. Reverse osmosis desalination system Normal seawater temperatures on the southern coast var y between 16 C and 21 C, and the total dissolved solids (TDS) of seawater is typically in the order of 35 000 mg/ℓ. The pH of seawater is slightly alkaline, between 7.5 and 8.5. The process of RO desalination involves the pressurised flow of raw water through
WATER AND WASTE WATER minute pores in membranes, separating the concentrate or brine from the product water. The membranes are typically housed in cylindrical cartridges, containing spirally wrapped membrane sheets. Up to seven of these cartridges can be installed in series in a single pressure vessel. Several of these pressure vessels are then installed in parallel bases on the required rate of production. The Mossel Bay RO plant is designed to recover approximately 40% of the incoming water as product water. The plant operates at pressures between 63 and 65 bar, and has an allowance for increasing the pressure as the membranes get older. Membrane replacement inter val is approximately 5 to 7 years. Post-treatment The objective of post-treatment is to ensure that the product water is safe to drink, and non-corrosive. The product water from the plant will have a total dissolved solids (TDS) content of generally less than 300 mg/ℓ, and a pH of approximately 6, which
requires limited post treatment to correct the pH. In the plant, disinfection is achieved through the addition of sodium hypochlorite (NaClO), and the correct pH maintained by controlled dosing of hydrated lime (Ca(OH)2.). These are normal water treatment processes and will provide water suitable for immediate consumption. Brine disposal In this plant, the brine (60% of the feed water) will have a salinity of ±60 000 ppm (seawater is 36 000 ppm) and a density of 1.044 kg/m3 (seawater density is 1.025 kg/m). Approximately 22.5 Mℓ/day of brine will be generated at full capacity. This is to be dispersed at a location approximately 500 m inshore of the intake, at a depth of -7CD in an area with a sandy bottom with little marine growth. The brine is discharged with a vertical velocity of 9 m/s or more through 19 diffuser ports installed onto a pressurised 630 mm HDPE pipeline to ensure rapid mixing of the brine plume and to ensure that no stratification occurs
with the higher density brine. All the pipes are installed underground, with no aesthetic impact, and will be corrosion resistant with long life expectancies. Bulk electrical supply The bulk electricity supply was upgraded using an underground cable from the intake substation directly to the site. The power demand by the RO desalination plant required operating rules to avoid Mossel Bay’s peak load being exceeded during peak demand hours and to prevent the contractual notified demand from ESKOM being exceeded. The permeate tank was sized so as to make use of off peak electricity to bring down the load and cost of supplying power. The intake substation has sufficient capacity due to the switch from the Hartenbos sub-station to the Sonskynvallei sub-station. The load from the intake and discharge pumps, desalination plant and BELOW Mossel Bay’s 15mℓ desalination plant
IMIESA JULY 2011 - 29
Water Puriſcation Plant & Equipment INTRODUCTION SWANSA (PTY) LTD trading as SWAN’S WATER TREATMENT is a privately owned South African company specializing in the design and manufacture of the full spectrum of water puriſcation equipment. Cost effective innovations are incorporated in our process and equipment designs with the plant being customised for each installation. Our extensive in-house expertise, ensures that out advanced technology is applied to the clients best advantage. PRODUCT RANGE • Water ſlters • Moore Airlift Rapid Gravity ſlters • Steel pressure ſlters • Steel rapid gravity ſlters Liquid/Solid Separation • Sludge Blanket Vertical Upƀow Clariſers • Diminishing Intensity Floc Conditioners • Incline Sheet Clariſers • Upgrading of Horizontal Flow Clariſers Chemical Dosing • Helical screw feeders • Rotary disc dry feeders • Water operated dry feeders • Gravity solution feeders • Metering pumps • Gas Chlorinators Efƀuent Treatment • Bioſlter rotary distributors • Aerators • Clariſers Miscellaneous • Package plants • Ammoniators • Sulphonators • Pilot operated diaphragm valves • Laboratory ƀoc testers • Automatic pH control • Comparators • Domestic and industrial cartridge ſlters
Swan’s Water Treatment Prop. Swansa (Pty) Limited Reg. No. 80/11814/07 Plot 91, Honingklip, Muldersdrift P O Box 777 Muldersdrift 1747 Tel: 079 699 5179 Fax: 086 609 1595 P Swan
WATER AND WASTE WATER product water pump stations indicate that, after diversity, peak demand will be in the order of: • Intake and discharge and product water pump stations: 2 x 1 600 kVA transformers (2 400 kVA running) for Mossel Bay municipality 1 duty and 1 standby pump, PETROSA 1 duty, 1 standby and the seawater intake (4 x 55 kw). • Desalination plant: 2 x 1 600 kVA transformers for RO [2 656 kVA running]. • Additional capacity supplied from intake s/s is 6.4 MVA, with no upgrading required. 2 x 185 mm, 11kV PILC cables, from the Lofty Nel substation to the plant, were also required. • The transformers are 1 600 kVA (20% spare capacity available at the desalination substation). • The estimate plant electricity demand will be in the order of 82 MW/day. Operation and maintenance The plant is a high-tech installation that requires correct operation and maintenance (O&M), which will initially be carried out by
Veolia Water Solutions & Technologies South Africa (Pty) Ltd for a three-year fixedterm period (that can be extended to 20 years), with training and capacity building of municipal staff a long term objective. A number of scenarios for the operation of the plant can be considered. From running it as much as possible, which will result in the lowest desalinated water unit cost, to running as little as possible, which will
result in a relatively high unit cost. The control philosophy and operating rules will take into account factors such as water demand, electricity use and the status of other raw water supplies. The overall water supply can be optimised to achieve the best supply option and meet water demand needs. TABLE 2: Professional team
PROFESSIONAL TEAM Mossel Bay Municipality PetroSA SSI Engineers and Environmental Consultants Veolia Water Solutions & Technologies South Africa (Pty) Ltd CVW Electrical Engineers Aurecon Group RLH Consult Engineers M&R Marine MVD Consulting Engineers (Southern Cape) Henra VE Reticulation House of Safety Consultants
Client and co-funder Client and co-funder Project principal Seawater desalination RO plant design, build and operate contractor Bulk electrical supply consulting engineers Environmental co nsultants Marine works Marine works (intake pipeline with structures and brine discharge pipeline with structures) Mossel Bay Municipality pump main and pump station Civil contractor for municipal pump main and pump Station H & S consultant IMIESA JULY 2011 - 31
SUPPLIERS OF VALVES, PIPE FITTINGS AND AUXILIARY PRODUCTS Elmien van Deventer 079 511 8605 CAPE TOWN
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Johan Steenkamp 082 882 0473 RICHARDS BAY
Nolada 8 CC an independently SEESA rated woman owned company, established in 2008 and valued supplier of the Mtubatuba water treatment plant, offers a full extensive product range of quality valves, pipes & fittings. Nolada 8 renowned for their expertise forms an integral part of the total supply team, ensuring that you are supported from introduction right through to after sales support. As an agent and national industrial supply agent of the AVK Group, we pride ourselves on our products in accordance with national and international standards. With the AVK unique Zero Maintenance, Zero leakage products, we embrace new ideas and operations, raising performance levels and reducing operation, installation and maintenance costs.
Elmien van Deventer MEMBER
We believe that the best practice in all industries is to treat each project as unique, particularly in challenging applications. You are far more likely to be successful in choosing the right valve at the right price with the right combination of features and characteristics. When we make a commitment to our customers and suppliers, we deliver on that commitment!
Maria Lotso Mahlangu MEMBER
WATER AND WASTE WATER
Municipality to provide basic services to informal settlements eThekwini Municipality will be providing interim services to selected informal settlements. Redcliffe and Kenville will receive basic roads, electrical services and storm water drainage systems.
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N THE PAST, the impetus on delivering a full housing product to a limited number of recipients shifted the focus away from the delivery of basic services to a wider population . “The interim services initiative acknowledges that there will be a large number of informal settlement communities that would simply have to wait years to be addressed by the housing programme but, given their social and economic situation, there is no reason why such communities cannot be immediately serviced,” explains Faizal Seedat, senior manager at eThekwini. These two areas are being used as pilot projects, and work has begun to provide roads, pathways and storm water drainage. An estimated 2 800 families living in these areas will benefit from the new infrastructure. “The pilot projects are being closely monitored so that the lessons learnt can be applied when the budget becomes available to facilitate the rapid roll-out of interim
services to other settlements in eThekwini,” says eThekwini project executive, Alan Kee. According to Kee, the priority is to provide roads and pathways, which will enable emergency services to access these areas in times of need. Once the roads are completed, the electricity department will move in to provide electricity connections in the settlements as part
of the Electricity for All (EFA) Programme. The pilot projects commenced in January 2011 and were due for completion in June this year. BELOW New footpaths and steps have been installed in the Redcliffe informal settlement near Verulam. This initiative is part of the municipality’s drive to improve living conditions in informal settlements
IMIESA JULY 2011 - 33
WATER AND WASTE WATER
Unlocking the potential of It is widely accepted that, while anaerobic digestion is a proven, highly effective treatment system, upsets in performance remain common. Claire Lipsett Pr.Sci.Nat., process specialist at Talbot & Talbot
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CORRECTLY RUN DIGESTER will efficiently convert up to 95% of organic material into a low-odour stabilised slurry and produce a renewable resource in the form of biogas that can be flared or utilised on site. This eliminates the need for additional solids handling and large-scale pond systems and limits reliance on non-renewable fuels. However, digester disturbances continue to represent a significant risk, preventing the widespread adoption of this technology. Under the Department of Water Affairs (DWA) water use licence conditions, the discharge of untreated effluent into water bodies following reactor failure can attract non-compliance penalties of millions of rand and, under special limit conditions, force full production shutdown of operations for lengthy reseed periods of the digester. Consequently, new applications are often over-engineered,
underloaded and relatively expensive. Despite decades of research into anaerobic digestion technology, the lack of a fundamental understanding of upstream effluent management, system sensitivity and basic process control continues to be highlighted as an ongoing concern, severely limiting the reputation and diversification of this technology. Talbot & Talbot continues to build and operate
Digester disturbances continue to represent a significant risk upflow anaerobic sludge blanket (UASB) digester treatment systems successfully throughout South Africa and Africa, across a wide range of industrial sectors. Digesters vary in capacity from 1 to 5 Mℓ/d, treating between 1 and 25 t/d of COD under general limit and special limit licence conditions. The company believes that a high-performance anaerobic digester (AD) treatment system is the result of a fully integrated approach, which begins with a systematic site water management plan
and process optimisation within the clients’ core business. Upstream focus is essential in preventing discrepancies in effluent data, which result in incorrectly designed, overloaded and poorly performing digesters for segregating and correctly disposing of solid waste streams and ensuring that potentially harmful contaminants are identified and isolated from the effluent system. Plant design and construction is offered on a full turnkey basis, in addition to a full aftercare service through Talbot Operations, a business division of Talbot & Talbot. This includes operator training, performance review and compliance monitoring on a support basis, and a dedicated team of competent operations and maintenance personnel on a fully outsourced basis. In addition, effluent sampling schedules are implemented via Talbot Laboratories to identify changes in effluent quality rapidly and monitor final discharge compliance. This guarantees the long-term treatment potential of UASB technology and a full commitment to the industry, which cannot be achieved on a ‘build only’ basis. A well-managed, high-performance AD system provides clients with the opportunity to recover water and energy resources from their effluent. Secondary treatment systems in the form of activated sludge (AS), sequential batch reactor (SBR) and biofilter technology provide exceptional effluent treatment options, while water reclamation can be incorporated via ultrafiltration and reverse osmosis technology. More recently, Talbot & Talbot has successfully designed and commissioned biogas recovery systems that capture the by-product of digestion, methane, as a renewable, CO2-neutral energy source. A 25 t digester with a biogas production of 6 500 Nm³/d can typically produce 52 t/d of steam, which supplements Digester disturbances continue to represent a significant risk
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WATER AND WASTE WATER
anaerobic digestion non-renewable energy use by up to 15%. The realised value of a biogas recovery project (BRP) is directly comparable to the cost of the fuel it replaces, the logistical cost of supplying fuel to remote locations and the availability of electricity throughout Africa. This system, coupled to an existing AD, typically offers a buy-back period of less than two years and forms a reliable, constant energy source for the industry that directly offsets the cost of effluent treatment. Despite these benefits, Talbot & Talbot states that the real value of BRPs is the renewed interest in AD technology, a deeper understanding of good effluent handling practices and an ongoing commitment to ensuring anaerobic digesters reach their full treatment potential. Anaerobic digestion is a proven treatment system IMIESA JULY 2011 - 35
WATER AND WASTE WATER
Gaborone sewerage system upgrade Halfway through ACE GIBB’s upgrade of Gaborone’s sewerage system, indications are that the project is headed for success. Large-diameter concrete pipes waiting to be installed
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HE REFURBISHMENTS to the systems are set to make a meaningful difference in the lives of Botswana citizens. “The R1 billion project involves the decommissioning of certain pump stations, refurbishment and construction of other pump stations and construction of trunk and main
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sewers in Gaborone to provide capacity up to the planning horizon of 2030. Furthermore, we are tasked with the sewering of some 6 000 remaining self-help housing area (SHHA) plots, which currently run on septic tanks,” explains project manager, Vernon Joubert. Gaborone’s sewerage systems have been strained for some time. As can be expected,
human activity, industrial waste, agricultural run-off, municipal dumping and oil spills all negatively affect water supplies. Owing to rapid growth in the capital, the capacity of its existing bulk sewerage infrastructure will soon be exceeded. Furthermore, pollution has also become a problem in the SHHA communities in Broadhurst.
WATER AND WASTE WATER
Counting every drop The past years have seen unexpected population growth in the City of Cape toTown. IMIESA looks at the city’s crucial WC/WDM strategy.
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HE LIMITED WATER RESOURCES available to the City of Cape Town mean that, without water conservation and demand management (WC/WDM), the unique ecology and environment are under threat. The City of Cape Town was the first metro in South Africa to implement a council-approved WC/WDM strategy. The strategy has a set of goals to be achieved through the implementation of project programmes from 2006 to 2016. The city has committed itself to the implementation of the WC/WDM strategy, saving approximately 90 million cubic metres per annum by 2016/17. Its strategy on water demand and conservation needs to be assessed to establish whether its goals are being achieved. The City of Cape Town has drawn on Vela VKE’s WDM expertise to measure the effectiveness of the strategy. A range of projects have been implemented to reduce water demand and conserve water.
The following statistics summarise some of the strategy achievements: • Pressure management has been implemented in more than 13 settlements. • 1 693 consumer meters were audited. Automated meter reading devices were fitted for 1 775 consumers. • 20 574 consumer water meters have been replaced, 17 998 consumer meters relocated and fixed and 70 652 water connection leaks fixed in the past three years (2007/08 to 2009/10). • There are 95 treated effluent users, which account for 80.5 Mℓ/d of reuse. • Caretakers from 341 poorer schools have been trained in basic plumbing. • 41 schools have been visited and their leaks repaired. • 160 Hlonipha Amanzi workshops, with 14 813 participants, have taken place. • There has been water by-law awareness campaigning, including five workshops, 12 shopping mall promotions and industry and commerce interventions.
Before
After
• More than 50 000 households were visited by the Integrated Leaks Repair Project. Vela VKE’s team had to provide the answer to the difficult but crucial question of whether the successful implementation of these projects has resulted in a reduction in water demand and losses. Assessment had to be critical and independent. It included data extraction and analysis for the evaluation of the International Water Association (IWA) water balance, financial and budgetary assessment and accurate estimations of achieved water savings. While the City of Cape Town is achieving significant savings, the assumptions made, particularly with regard to population growth, have proven off the mark. Vela VKE has set out a way forward, which includes a revised strategy to take into account increased population growth. IMIESA JULY 2011 - 37
HEAD OFFICE: BLOCK C - Menlyn Corporate Park C/O Garsfontein Road & Corobay MENLYN - PRETORIA Tel: +27 (0) 12 940 1111 FAX: +27 (0) 86 743 3100 E-mail: marketing@bviho.co.za
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Mining Infrastructure Engineering Procurement Civil Engineering Electrical Engineering Structural Engineering
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Mechanical Engineering Environmental Management Construction Management Feasibility Studies Project Management
O f f i c e s : T s w a n e , Po l o kwa n e , C a p e T o w n , Bloemfontein, Upington, Springbok, Empangeni, Durban, Port Elizabeth, Mozambique,Namibia, Angola
WATER AND WASTE WATER
Boosting the capacity of the Zeekoegat WWTW The Murray & Roberts Construction Power joint venture is making headway on a R190 million contract to execute stage 1 of the upgrade and expansion of the Zeekoegat WWTW on the Pienaars River.
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HE CONTRACT WAS AWARDED by the City of Tshwane in October 2010 and calls for the construction of a new 40 Mℓ/d biological nutrient removal activated sludge (BNRAS) module to boost the existing capacity of the wastewater treatment works (WWTW). Completion is scheduled for early 2013. Detailed design and supervision of the extensions was awarded to the BAKV3 joint venture, comprising BIGEN AFRICA Services and KV3 Engineers. Anton Botha, contracts director at Concor, a subsidiary of Murray & Roberts, says the contract has taken a unique turn in that in addition to the civil work, the Murray & Roberts Construction Power joint venture (M&R Construction Power JV) has been given responsibility for project managing the mechanical, electrical and instrumentation components of the work, including dry and wet testing, commissioning and final handover of the plant to the client. Lektratek Water Technology is the mechanical partner and EDSE Projects is the electrical partner on this project. “This ‘single source’ approach is unique in the civil industry,” explains Botha. “We have established excellent relationships with the mechanical and electrical contractors and we are proving that we can successfully co-ordinate the implementation of these disciplines in a project of this nature. Based on this track record, we are already tendering for other similar projects offering the same ‘package deal’ approach.” The JV will supply 15 000 m3 of concrete, 47 000 m2 of formwork and 1 600 t of reinforcement for stage 1 of the Zeekoegat WWTW upgrade and expansion. The modifications to the existing works
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include the supply and installation of a third 8 mm screen at the existing screenings chamber, construction of three additional vortex degritters and a new division box to split the flow between the existing and the new module and construction of a new finescreen structure. The contract includes three new conventional 25 m-diameter primary settling tanks, equipped with rotating bridges and scrapers. Primary sludge will be drawn off to a new primary sludge pump station, which will transfer it to a sludge handling facility, to be constructed during stage 2. A new 10 000 m3 balancing tank will allow a six-hour retention period and will be equipped with 16 vertical shaft stirrers to prevent the organic matter from settling. Two identical new biological reactors, each capable of handling 20 Mℓ/d, are being constructed and configured to incorporate several process configurations. Diffused aeration has been chosen as the method
of aeration based on its energy efficiency and the fact that the existing plant already operates on diffused air. The unaerated zones will be equipped with 40 vertical shaft stirrers and 20 axial flow pumps will be installed for internal recycling purposes. Included in stage 1 are four new 35 m-diameter secondary settling tanks, equipped with rotating bridges and scrapers. Return activated sludge (RAS) will be withdrawn and pumped to the biological reactors. A new chlorination contact tank has been sized to handle the eventual total flow of 85 Mℓ/d. The tank has been split into two separate units to allow for disinfection to take place when one unit is taken out of operation for cleaning and maintenance. An additional estimated electrical load of 4 MVA will be required for the extensions to the plant. The bulk power on site will be distributed to various 11 000/400 V substations and mini substations.
The Murray & Roberts Construction Power JV is responsible for the mechanical, electrical and instrumentation components of the work at the Zeekoegat WWTW
INDUSTRY NEWS
Climate change seminar
Addressing the skills shortage With the critical shortage of engineering skills in South Africa, GIBB, a multi-disciplinary consulting engineering company, are making a difference through investing time and resources in future talent development.
This three-day course will cover climate change agreements, basics of CDM, methodologies and tools, verification and issuances, accounting and neutralisation of carbon footprinting and the functionality and exchanges of carbon markets. Date: 26 to28 July 2011 Venue: Emperors Palace Convention Centre, Gauteng christina@eventstraining.co.za
GIBB is doing their part and showing they care by helping to educate and develop engineering students through site visits and exposure to actual projects. This initiative is being championed by GIBB senior associate, Wouter du Toit, on behalf of the company. Du Toit has a direct understanding of the need for students to be exposed to real life situations and site inspections, in order to fast track their learning and understanding of the industry Du Toit has launched an initiative that sees GIBB hosting students from the Nelson Mandela Municipal University (NMMU) in the Eastern Cape on a regular basis, exposing them to a variety of projects. “Because of GIBB’s diverse portfolio of clients and projects spanning 11 sectors, we are able to arrange site visits ranging from building construction projects to dams and roads,” says Du Toit. The first of these student visits recently took place through the GIBB Port Elizabeth Office. Thirty NNMU students were invited to attend the rock blasting taking place at The Boardwalk Casino’s new multi-storey parkade, conference and 5-star hotel construction site. The location visit included a walk around the proposed new site area, accompanied by Brink Botha, senior lecturer and acting head of the Department of Construction Management. “We find that giving the students the opportunity to experience a project on-site gives them the opportunity to witness firsthand what they are being taught in the class room”, added Du Toit. IMIESA JULY 2011 - 39
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INDUSTRY NEWS
IMESA 2011 Conference and Exhibition
Kelvin Pillay has been appointed as sales engineer at peristaltic pump specialist Watson-Marlow Bredel SA’s head office in Johannesburg. He has extensive experience across the pump industry, from the mining and petroleum sectors to food, beverage and pharmaceutics.
an opportunity to share ideas and constructively debate challenges facing engineers in the municipal environment. Date: 26 to 28 October 2011 Venue: Birchwood Hotel and OR Tambo Conference Centre www.imesa.org.za
The Northern Provinces branch of IMESA will host the 75th IMESA Conference and Exhibition, themed: ’Yesterday, Today and Tomorrow’. The conference will offer delegates
40 - IMIESA JULY 2011
IFME 2012
SAHF 2011
The IFME World Congress of Municipal Engineering takes place every three years and brings a global community of municipal engineers and design professionals together. The main theme of the 2012 event will be sustainable communities.
With the housing backlog increasing, South Africa needs to consolidate its resources and focus on innovative ways to reduce the housing crisis. There is urgent need for the public and private sector to work more closely together.
Date: 4 to 10 June 2012 Venue: Helsinki, Finland www.ifme2012.com
Date: 11 to 14 September 2011 Venue: Cape Sun, Cape Town www.sahf.org.za
GEOTECHNICAL
A duty of care – geotechnical instrumentation Geotechnical design is, to some extent, hypothetical and every construction project involving earth or rock runs the risk of encountering the unexpected.
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HESE CIRCUMSTANCES are the inevitable result of working with materials created by nature and by process seldom resulting in uniform conditions. The inability of exploratory procedures to detect all possibly significant properties and conditions of natural materials requires the designer to make assumptions that may be at variance with reality and the constructor to choose equipment and construction procedures without full knowledge of what might be encountered. Field observations, including quantitative measurements obtained by field instrumentation, provide the means by which the geotechnical engineer can design a project to be safe and efficient, and the constructor can execute the work with safety and economy.” – Ralph B Peck, 19881 Peck is known as ‘the godfather of soil mechanics and was directly responsible for a succession of celebrated tunnelling and earth
dam projects that pushed the boundaries of what was believed to be possible. Peck has summed things up totally and it could be argued that there is nothing more to be added on why geotechnical engineering is so important. Then again, some elaboration may be called for and here is why we should instrument our civil engineering and mining projects. Firstly, there are benefits to be gained during the design of a project. Instrumentation may be used to assist with assessing the in-situ geotechnical conditions during the design phase. A simple example is the installation of piezometers to monitor groundwater levels and hydraulic head. More complex examples include the assessment of in-situ stress and deformability conditions in the design of tunnel linings or large, underground excavations. By understanding the geotechnical conditions, a more focussed design can be arrived at.
Furthermore, designs have inherent uncertainties and, to a large extent, these are circumvented by using conservative design parameters and that 'fudge' factor called the factor of safety. However, if we were to reduce the degree of uncertainty in a design by carrying out a proof test, the advantages of this would be obvious. A proof test will include observations on behaviour and may well include instrumentation. Then there is the issue of crisis management. Should a crisis arise, the nature of the problem needs to be defined so that remedial measures can be implemented. Secondly, there are benefits to be gained during construction, including improvements in safety for construction workers and the public, a reduction in construction costs, greater control over construction procedures and an enhancement of public relations. IMIESA JULY 2011 - 41
GeoZone GeoServices provides a geotechnical service to the broader engineering and mining industries. Through close associations with SISGeo Italy for geotechnical and structural instrumentation, and Geobrugg Switzerland for rock fall protection systems we are perfectly placed to bring state -of-the-art technologies to bear in solving any geotechnical problem. GeoZone GeoServices provides, amongst others, the following services: • Geotechnical Instrumentation for dams, tunnels, bridges and structures • Rockfall Protection Systems ‒ a one stop shop for design, supply and installation • Installation of rock anchors, catch nets and mesh through Rock Africa • Slope Stability Assessments • Rock Engineering • Foundation design
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WASTE
Tshwane residents to benefit from new waste management fleet The City of Tshwane Agriculture and Environment Management Department has increased its waste management fleet by acquiring new vehicles from Daimler Fleet Management.
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T A HANDOVER at Mercedes-Benz South Africa’s (MBSA) head-office in Zwartkop, the City of Tshwane officially acknowledged acceptance of a massive fleet of 92 specialised Mercedes-Benz trucks for the city’s waste management service. The fleet includes Mercedes-Benz Actros, Axor and Atego vehicles in a variety of tailor-made waste applications, from skip loaders to side loader refuse compactors. These units are specifically built to the City of Tshwane’s specifications and the unique par tnership with Mercedes-Benz Commercial Vehicles allowed for some of the more specialised vehicles to be built at Wörth, Germany, shipped to Italy for the specialised fitment and then sent on to South Africa. The value of the three-year contract is estimated at be R216 million. Tshwane’s Executive Mayor, Cllr Kgosientso Ramakgopa, was delighted with the progress made in this aspect of the council’s ser vice to its residents and expressed satisfaction that the partnership with DFM and the Mercedes-Benz dealer will assist in providing greater operational efficiencies. Speaking at the function, Ramokgopa said that the new fleet would assist the city to achieve its goals of being the cleanest city in the country. “We have, over the years, constantly won the Bontle ke Botho award for a clean city. These trucks will ensure that we keep that track record,” said Ramokgopa.
“Over and above that, we will be able to fulfil our mandate to keep the city healthy.” During his budget speech, the mayor promised that waste management would receive increased attention. He said at the time that waste management was a critical function that needed to be fulfilled with care, lest there be disease outbreaks that could easily be prevented. This is the second largest single fleet lease contract that DFM has won and we are delighted that the City of Tshwane put its trust in us by awarding DFM the entire contract,” said Aluwani Ramabulana, CEO of Daimler Fleet Management. “We are delighted with this unique partnership between the City of Tshwane, the Mercedes-Benz Commercial Vehicle Division
at MBSA, equipment specialist OMB-SA and the servicing dealer Sandown Motors’ Mercedes-Benz Commercial Vehicles Centurion,” added Ramabulana. Details of vehicles selected for this contract: 40 units of Mercedes-Benz Actros 3332P/45 6X4 LWB, each complete with a vehicle monitoring system, FM radio/CD player, fire extinguisher, immobiliser system, crew cab, amber rotating lights, container handling (chain hoist) system and OMB Varia twin side-loader refuse compactor. The fleet includes Mercedes-Benz Actros, Axor and Atego vehicles in a variety of tailor-made waste applications
IMIESA JULY 2011 - 43
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KIMBERLEY
Three key WWTW upgrade phases Existing works at Homevale WWTW are in a poor condition. Sol Plaatje Municipality has thus commissioned the upgrade of the treatment plant from 30 Mℓ/day to 48 Mℓ/day.
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HE SOL PLAATJE MUNICIPALITY is serviced by three wastewater treatment works, namely Homevale, Ritchie and Beaconsfield. All three treatment plants currently operate at, or over, their design capacity. It is expected that both population growth and housing development in the area will add additional pressure to the provision of wastewater treatment services. Existing works at Homevale were in a poor condition, with incoming flows exceeding treatment capacity. A moratorium was placed on the development due to insufficient wastewater treatment capability. The new WWTW will be able to handle daily capacities of 48 Mℓ. The upgraded Homevale WWTW will service the major suburbs of Kimberley, specifically the new housing developments for China, Retswelele, Donkerhoek, Phutanang, Jacksonville, Lerato Park, Legaheng and Northgate. Ringing in at an estimated total project cost of R200 million, Sol Plaatje Municipality appointed Aurecon
BELOW Construction of the new flow splitter RIGHT New Chlorine Building
IMIESA JULY 2011 - 45
KIMBERLEY Consulting Engineers to provide professional services, which include design, tender documentation preparation, project management services, contract administration and site supervision. Project details The Homevale WWTW upgrade project has been divided into three key phases: • An emergency contract to address crucial problems at the plant. • A full upgrade to restore the works to its original design capacity. • An extension of the works to address future wastewater treatment requirements in the area. Phases I and II are currently underway. An environmental impact assessment is being carried out for the extension and further work with regard to this phase will only take place once a record of decision is submitted. Project planning commenced in 2009, followed by refurbishment construction works in 2009 and 2010. Design of new works started in 2010 and continued through to the first quarter of 2011. Construction completion date is set for August 2012. The design consists of the following: • refurbishment of outfall sewer • inlet works • primary settling tanks • bio-reactors • secondary settling tanks and anaerobic digesters • addition of new chlorine facilities • sludge drying beds • secondary settling tank • complete new activated sludge treatment lane, including aerobic digestion. BELOW M&E installation SST3
46 - IMIESA JULY 2011
ABOVE Construction of the new flow splitter
PROJECT TEAM Consultants Aurecon Contractors Marange, Empa, Eigenbau and Botjheng Contractors for new lane to be awarded Materials used in the construction Concrete, mild steel, stainless steel, glass, reinforced polyester
KIMBERLEY
Improvement of gravel roads The Frances Baard District Municipality, in conjunction with the Department of Roads, has embarked on a roads maintenance and upgrade project to improve accessibility of the local network.
T
HE FRANCES BAARD DISTRICT GROWTH AND DEVELOPMENT STRATEGY describes the Frances Baard District Municipality (FBDM) as a weak region because of its poor urban economy, ‘small’ population and regional economies. The district has an estimated unemployment rate of about 41% and the service sector provides more employment opportunities in the district than any other sector. Therefore, community services, trade, agriculture and finance are the principle employment generators in the area. Most of the employment opportunities are located in Sol Plaatje (61%), Phokwane (19.9%), Dikgatlong (11.4%), Magareng (4.6%) and the DMA (3.1%). The FBDM, in collaboration with the Department of Roads, has signed a service level agreement in which it is committed to maintaining the provincial gravel roads in the Frances Baard District, on condition that the Department of Roads provides the required funds. The provincial roads have deteriorated continually over the years owing to: • Lack of funds from the department to maintain provincial roads • Lack of machinery: it is either limited or is not functional. So, although the total road network within the district is about 1155.2 km, 62% of the network consists of divisional roads and only 439 km is made up of main roads. The condition of the gravel roads is satisfactory as only 17% of the road network is described as poor. In line with the roads network improvement, Namakwaland
Konstruksie was appointed by the FBDM to undertake a blading of roads project, with the objective of maintaining safe and accessible roads for road users yearly. The project commenced in November 2010 and will run for an estimated 12 months, during which time quarterly progress reports are to be submitted to the council and monthly reports to the Department of Roads. The project is scheduled for completion by November 2011
IMIESA JULY 2011 - 47
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TRANSPORTATION
Another link for integrated public transport The Johannesburg Development Agency (JDA) has been involved in numerous inner city projects, including the first bus rapid transit (BRT) project in South Africa. Candice Landie takes a closer look at the latest BRT developments along Rissik and Harrison Streets. Aerial photos image courtesy: Clive Hassall
T
HE JOHANNESBURG DEVELOPMENT AGENCY (JDA) is responsible for all infrastructure and construction developments on Johannesburg’s Rea Vaya (BRT) project, with a key element being the stations. A specific station look and feel was required for the city. The stations have to be constructed in limited time frames and under
very restricted working conditions, due maily to heavy traffic congestion in the central business district (CDB). “Due to the extreme construction pressures within the CBD, the station modules are designed off-site, and assembled on-site, once the foundations are complete. The stations have to be quick to construct,” says
Vuyiswa Voyi, senior development manager at the JDA. The stations are placed in the centre of roads along trunk routes at approximately 500 m intervals. In addition, level boarding and alighting from buses is required. Physical An aerial view of the Orlando BRT station and Orlando Stadium
IMIESA JULY 2011 - 49
TRANSPORTATION
REA VAYA STATION SAFETY FEATURES Level resting sections or landing areas halfway up the station ramps. Ramps that flatten for a length of 1 m approaching the station entrance. No-skid, block-paved ramps. Light emitting diode LED lights along ramp edges for increased visibility at night. Same-door entrance and exit. Emergency exit ramps in line with fire regulations. Ticket counters that are at a height accessible to seated persons and children. Ticket booth glass that has a built-in induction loop and handsets to enable better communication for people with hearing aids. 900 mm wide turnstiles that accommodate commuters carrying luggage, pushing prams, in wheelchairs, etc. Colour contrasts used for warning and guidance throughout the stations, for example. on chrome surfaces like handrails, door edges, the upper edge of ticket counters, etc. Lean rails inside the station (but no seating). Signage in pictograms where possible, audio announcements and vehicle management system. The development of detailed way-finding signage plans (still to be fully implemented). Ambassadors deployed at each station to assist commuters and guide special needs passengers.
site constraints dictate the ultimate configuration of a particular station. Typical configurations are: • Back to back, single-sided (uni-directional), staggered and staggered offset or special designs. • Stations can have one or a number of modules (buildings), depending on the capacity requirements, in any of the above configurations. • Rea Vaya station modules are standardised into four standard widths (for ease of construction), namely 3.5 m, 4.5 m, 5 m and 5.5 m. • Entry to stations can be shared between modules, or modules can have separate entrances. The stations are designed to be efficient, cost effective and low maintenance (whilst utilising natural lighting and natural
The stations are designed to be efficient, cost effective and low maintenance ventilation). Each station also takes the needs of all commuters into consideration, especially those with special needs. Rissik and Harrison At a total cost of R89.13 million, the Rissik and Harrison Streets BRT development forms a critical part of the Rea Vaya network and will link the Johannesburg CBD with Trunk route 1 and 2 (and will RIGHT An aerial view of the bus depot
50 - IMIESA JULY 2011
further link with the Gautrain). This section of the project provides a south-north trunk route (dedicated bus way) between Trunk Route 1 (T1), which runs along Market and Commissioner Streets, and Trunk Route 2 (T2), which connects Noordgesig, Coronationville, Auckland Park and Parktown. Both T1 and T2 connect with the Gautrain at Park City. The project forms part of the Integrated Rapid Public Transport Network, a National Department of Transport initiative aimed at improving public transport systems. Construction on the project started on 17 November 2010 and is scheduled for
ABOVE A completed BRT station
completion on 17 November 2011. It includes the upgrading of sidewalks, civil design: roads and services (water, stormwater, electrical and street lighting), structural design: BRT stations, pavement design: road layer works and sidewalks, and geotechnical engineering. The scope of works is as follows: • Plein Street, between Harrison Street and Rissik Streets: The construction of the bus lanes are for two directional bus traffic, bounded by one mixed traffic (private and public users) lane in each direction.
TRANSPORTATION • Rissik Street, from Commissioner Street to Plein Street: This section consists of the construction of a single bus lane bounded by single mixed traffic lanes. The mixed traffic lanes are not reconstructed (except at the station), and are rehabilitated by the milling off and construction of a new asphalt overlay. • Harrison Street, from Plein Street to Commissioner Street: This section consists of the construction of a single bus lane bounded by mixed traffic lanes. The mixed traffic lanes are generally not reconstructed (except at the station), and rehabilitatedby the milling off and construction of a new asphalt overlay. The exception being between Bree and Jeppe Streets, where the full road width has been reconstructed to improve the road cross-section. • Rissik Street north, between Plein Street and Smit Street: The construction of bus lanes in this section consists of a double lane for two-directional bus traffic. Two northbound mixed traffic lanes are provided on the west side of the two directional bus lanes. The mixed traffic lanes are not reconstructed, except where the road angle is too steep to accommodate trafficked lanes at the station and for road widening. The road is rehabilitated by the milling off and construction of a new asphalt overlay in these sections. • Construction of two BRT stations along Rissik Street and Harrison Street. A BRT station under construction
MATERIALS USED FOR THE BRT LANES -40 mm asphalt surfacing -150 mm asphalt base -150 mm upper sub base -150 mm lower sub base -150 mm sub grade
PROJECT TEAM Project managers Design engineers Quantity surveyors Health and safety agent Public participation consultant Environmental control officer Contractor
Archway Projects Gibb Davis Langdon Empowerisk Nemai Consulting Nemai Consulting Lonerock / Maziya JV IMIESA JULY 2011 - 51
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PIPES PUMPS AND VALVES
New range of pumps puts competition in a 'hole'
A
N EXCLUSIVELY BRANDED RANGE of world-renowned borehole pumps has been introduced to the agricultural, domestic and irrigation sectors of the South African market by leading irrigation and water pumping expert, Incledon. Having stocked the Pentax Booster range in South Africa for many years, Incledon further obtained exclusive national distribution rights for the Italian-crafted Pentax range of borehole pumps in November 2010. Incledon Pumps and Irrigation manager, Romeo Giannone, says that the brand has been well received as a high-quality but more affordable and reliable choice for consumers. Pentax has been distributed in South Africa since the early 1980s; however, Giannone points out that the company decided to introduce the borehole range to fill a gap in
Pentax has been distributed in South Africa since the early 1980s the market. “Incledon has supplied a wide range of cost-effective Pentax Booster pumps to numerous industries in South Africa. The company has, however, identified the need for residential and agricultural borehole pumps. The Pentax range was selected because it is an established brand that is synonymous with quality, locally and internationally.” Giannone notes that feedback from clients has been overwhelmingly positive. “More than 160 pumps have been sold nationwide since the range was officially launched in South Africa. This is thanks to the fact that the pumps are more durable, reliable and quieter than any other products in the same price range. Having set a target of selling 500 units by June 2011, Incledon is already well on its way to exceeding expectations.” All of the pumps are manufactured from 304 stainless steel, with Noryl impellers and polycarbonate diffusers, the most versatile
and wear-resistant alloy used in the manufacture of pumps. In addition, the Pentax borehole pumps range consists of models with flow rates ranging from 500 ℓ/h to 24 000 ℓ/h, with pressure ratings of between 35 m and 280 m. Giannone says that quality and after-sales service sets this range apart from the competition. “Most pump manufacturers only carry out batch testing, in that only one or two models coming off the production lines are tested. Pentax, however, tests every single pump for hydraulic and electrical faults before they leave the factory in Verona, Italy.” All Pentax borehole pumps are National Electrical Manufacturers Association (NEMA) and European Conformity (CE)accredited and come standard with a 12 month manufacturer’s warranty. “As exclusive custodian of the Pentax brand, Incledon prides itself on being able to deliver on all brand-related warranties. Incledon is committed to providing the highest levels of technical and after-sales support to its clients and regularly provides full technical training on all products on site and at the dedicated Incledon training workshop located in Johannesburg,” he continues. The biggest challenge in introducing the Pentax borehole range to the South African market was not market related, but in fact weather related. “The unusually wet summer had a negative impact on sales, as borehole drillers were unable to gain access to sites, owing to the muddy conditions which are unsuitable for rigging,” he explains. “Incledon has, however, seen a spike in demand since March, as the weather has become drier.” Despite the fact that Incledon is currently competing in this particular market at midmarket level, Giannone is confident that the company will obtain significant market share with the Pentax borehole range of pumps in the short-term future. Pentax borehole pumps
IMIESA JULY 2011 - 53
PIPES PUMPS AND VALVES
Giant sludge presses Following its success with Bellmer presses, Bateman Engineered Technologies has been awarded distribution rights in South Africa for Bellmer Kufferath Machinery.
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ELLMER KUFFERATH Machinery (BKM), a member of the Bellmer group since 2008, designs and produces plants and systems for dewatering, thickening and sorting and its expertise extends across a wide range of applications, including thickening and dewatering of sludges and fibres, treatment and dewatering of rejects, waste dewatering, dewatering in plastic recycling systems, dewatering of explosive and/or corrosive media and more. “We have had many years of success with Bellmer Winklepress belt presses in Southern Africa in municipal wastewater treatment plants and in the paper and fruit juice industries. We also recently successfully launched a Bellmer Winklepress mobile dewatering plant for sewage and effluent sludge. All this encouraged Bellmer to ask us to distribute its BKM products in this region,” says Bateman Engineered Technologies (BET) Water and Effluent manager, Marius Botha. The priority among the BKM product range is screw presses for the dewatering of fibres, sludges and rejects. With several lines of AKUPRESS® screw presses and a wide range of sizes, from 200 to 1 400 mm, BKM is one of the world’s world s leading suppliers of screw presses.
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Botha adds that the broad scope of industries in which these products and services can be utilised include pulp and paper, food and food recycling, digestion technology, waste processing, plastics recycling, leather and the chemical industries. He also praises the high level of BKM’s quality, saying: “This company plans carefully, taking the customer’s requirements into account When a machine leaves its factory, one can rest assured that it is in perfect condition, ensuring minimum downtime and maximum productivity for the user”. In 2009, BKM delivered six AKUPRESS®AS 625 screw presses to GRD Minproc in Australia, for use in the Urban Resource-Reduction, Recovery and Recyling (UR-3R) Process®. This combines several technologies for mechanicalbiological recovery of mixed urban waste. A repeat order for a similar project in the UK was placed last year. “All over the world, the BKM products are achieving excellent results and we are looking forward to similar results in Southern Africa,” maintains Botha.
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Shipment of a sludge press with a screw diameter of 1 400 mm to the UK
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PIPES PUMPS AND VALVES
Investing in infrastructure The Msunduzi Municipality is investing nearly R20 million to reduce the high number of water leaks in its reticulation system.
T
HIS IS THE FIRST PHASE of a highimpact water conservation and water demand management initiative that is expected to boost service delivery and halve water leaks over the next three years. “The Msunduzi Municipality has recently embarked on a large-scale initiative to reduce the high level of water losses in its distribution system. The municipality is currently implementing a number of high-impact interventions that will ensure compliance with the
Presidential Directive of halving water losses by 2014,” says Msunduzi mayor, Mike Tarr. As part of this initiative, two third-year engineering diploma learners have been integrated into the programme. The Durban Institute of Technology's (DUT) learnership programme, known as Singakwenza Ndawonye, generates funding that is used for the theoretical element of the course. In effect the funds paid to the DUT will pay for the learner’s continued education. “The idea is to grow the number of
ABOVE Msunduzi mayor, Mike Tarr, acting Executive Water district manager, Brenden Sivparsad, Msunduzi administrator, Sibusiso Sithole and executive manager: Marketing and Public Relations, Brian Zuma
learnerships on the Msunduzi programme to four. The learners will work their six months’ practical training on the Msunduzi project,” explains Tarr. Tarr says that phase 1 began in December last year. The Department of Water Affairs (DWA) is contributing R3 million of the R22.1 million budget. IMIESA JULY 2011 - 57
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PIPES PUMPS AND VALVES
SA engineers go green at pumps show
L
ATEST DEVELOPMENTS in ‘green’ energy-saving pump technology went on show before a delegation of leading South African built industry consultants touring the Wilo and Salmson pump research and manufacturing centres in Germany and France. The tour programme was coordinated with a visit to the biennial ISH trade fair in Frankfurt, the world’s biggest exhibition
of building, water, energy, air-conditioning and renewable energy technologies, where 2 400 international companies put their products, services, technology and design expertise on show. The week-long tour provided some of the South African consultants with an introduction to Wilo’s new range of high-performance pumps, which have demonstrated significant energy-saving capabilities at major industrial
installations in Europe. “High efficiency was the central focus of the ISH show,� says Wilo South Africa managing director, Errol Cornelius, who led the group. One member of the consultant’s team, Candice Moolman of the WSP engineering consulting group, states, “It was good to get a clear understanding of the green Wilo technology now available to us in South Africa and to get a close-up look at the design and quality standards involved in the manufacture of the new Wilo high-performance pumps.� Another consultant, Riaan Steyn of SCE Namibia, adds: “One could see that Wilo is on the right track as far as energy-efficient pumps are concerned. Green is obviously the way to go, and with power costs on the rise, high-efficiency pump technology will progressively become even more important in the future.� The consultants group also inspected Salmson pump manufacturing and research operations in France. Green technology in pumps has been showcased
58 - IMIESA JULY 2011
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PIPES PUMPS AND VALVES
Fashionable concrete in advert campaign
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LWAYS DELIVERING: This picture, taken recently, shows a hoarding at Sandton City, advertising the current refurbishments and extensions to the centre. The hoarding has not escaped the attention of the Concrete Manufacturers Association (CMA), which is pleased to note that concrete pipes were chosen as the central prop. Being symmetrical and a mottled grey, the pipes have an austere beauty, providing the perfect foil for the model in her red evening gown. CMA director, Hamish Laing, notes: “It is not through chance that concrete pipes have been in style for over a century. They continue to offer consistent dependability, durability and cost-effective functionality, and are likely to dominate the market for reliable water conveyance well into the foreseeable future.” IMIESA JULY 2011 - 59
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AGEING INFRASTRUCTURE
Population growth THE EFFECT ON SOUTH AFRICA’S WATER SYSTEMS Urban sprawl, or population explosion, is evident in South Africa with formal housing developments and informal settlements spread out across the country’s major cities. The cost of maintaining ageing infrastructure, as well as the demand for new infrastructure in these regions, is stretching local government budgets. By Candice Landie
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HETHER POPULATION EXPLOSION outstrips economic growth and perpetuates unemployment in South Africa; or whether national government has introduced any measures to control the population expansion, is not the issue at hand. Before South Africa considers implementing laws and restrictions to control population growth, we need to be realistic about the situation as it currently stands. South Africa experienced a significant increase in population growth post 1994, particularly in informal settlements, which has, and continues to, impact negatively on local infrastructure systems such as water (this includes storm water drains, sewerage systems and access to safe drinking water). In late 2009, finance spokesperson for a local political party let slip during a media interview that the country’s backlog in
municipal water maintenance was a staggering R50 billion. Whether or not this statement holds truth is yet to be decided. In my quest to reveal whether any work is been carried out on water infrastructure at local government level, I took a drive through the infamous Alexandra Township in Johannesburg. Township findings In order to get an objective overview, my first visit was through Section 10 of Alexandra Township, where housing developments are currently under construction. The development in this area consists of the construction of decent brick houses and roads, electricity and water supply for each house, and sewerage works. This development forms part of the Alexandra Renewal Project (ARP), a programme which was started in 2001 and forms a key component of government’s approach to
POPULATION GROWTH RATE
RANK
2008
0.83
137
2009
0.28
172
-66.27%
2009 est.
2010
-0.05
201
-117.86%
2010 est.
2011
-0.38
220
660.00%
2011 est.
YEAR
TABLE 1:
60 - IMIESA JULY 2011
PERCENT CHANGE
DATE OF INFORMATION 2008 est.
AGEING INFRATRUCTURE
and ageing infrastructure addressing urbanisation. For the urban poor, Alexandra is a prime location. While the physical infrastructural capacity of Alexandra should be no more than 70 000 residents, in reality it houses five times that number. An estimated 350 000 people live in Alexandra. In short, the purpose of the ARP is to upgrade the living conditions within the area. The other side of the river For those who are not familiar with the township, the area is situated on the banks of the Jukskei River. The developments in Section 10 are divided by the banks of the Jukskei, thereby keeping the ‘under-developed’ section of Alexandra apart from the construction that is currently underway. Driving through the ‘untouched’ half of Alexandra was quite an experience. Apart from the refurbished roads,
there is not much else to show in terms of infrastructure development. Blocked storm water drains are still visible, as are leaking water pipes and drainage systems, which overflow onto the streets. A show entitled ‘Speak Out’, which broadcasts on SABC 2, recently aired an episode on the state of Alexandra’s water infrastructure to coincide with the 2011 local government elections. For many households, access to running water is a luxury, so these houses have no fitted drains and residents resort to throwing their used water into the streets. Sewage drains overflow onto the roads and pose a serious health risk to residents, particularly children and the elderly. Poor water infrastructure maintenance also has a negative effect on the roads and causes huge cracks and potholes. Despite the negativity surrounding infor-
ABOVE Most of the older sections of Alexandra in Gauteng are in dire need of upgrade projects IMIESA JULY 2011 - 61
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AGEING INFRASTRUCTURE ARP PROGRAMME STATUS 2001 TO 2004
2005 TO 2009
2009
ONGOING PROGRAMMES
Spatial Framework developed Alexandra police station upgraded (Wynberg) New central Alex police station built People Centre built All 18 schools upgraded All clinics upgraded Crèche converted into child and family resource centre 2 054 trees planted 2 parks upgraded 3 new parks developed Cemetery upgraded 8 500 families relocated out of Alexandra 1 400 housing units built within Alex (incl. River park) 350 Social housing units in Old Alex Alex transit Village built (550 units) Marlboro Transit Village upgraded Upgrading of water mains Construction of water reservoir Outfall sewers upgraded Electricity supply upgrade & 12000 connections 46 000 waste bins distributed 10 km of roads in Old Alex upgraded 3 km of road in East Bank surfaced London Road widened London Road bridge widened Wynberg City Improvement District established Economic clusters operating (retail, auto, construction) Alexandra Development Forum established.
Teachers Training and Resource Centre Wynberg / Pan Africa intersection Ekukhanyisweni Primary School ATV Storage Facility River Park Library Jukskei River open space: Phase 3 M2 (Nobuhle) Hostel upgrading: Phase 1 Diepsloot Multi Purpose Centre Business Development Centre Edenvale Aids Clinic Edenvale Hospital Pharmacy Edenvale Hospital Outpatients Bombani Safe House Kwa Bhekilanga Athletic / Rugby Facility: Phase 1 Altrek Sports Facility upgrading Alex Stadium River bank protection Ext. 7 Pedestrian Bridge Jukskei Park Pedestrian Bridge Upgrading of existing Cemeteries Business Support Centre East Bank ECD facility 9 km sidewalk upgrading 15 km road build and upgrade Jukskei Park: Phase 3 2 Community parks Greening of Far East Bank Ext. 8 3500 trees planted Storm water curb inlets upgraded (120) 2 large hot spots upgraded Yard ablutions upgraded: Phase 1 Electricity Master Plan 30000 connections History of Alexandra documented M2 Hostel: Phase 1 520 rented rooms Emergency housing facility Marlboro BNG Flats Phase 1 Far East Bank Ext 7: 1402 housing units Marlboro Combined School grounds upgrade Bombani Park
Gordon Primary School Vasco da Gama Bridge Community cluster homes 400 Informal trading stalls K206 Housing Ext 9 Redevelopment of Pan Taxi & Retail
Development of open space Local economic development Jukskei River upgrade Implementation of Storm Water Master Plan Upgrading of ablution facilities Upgrading of roads and sidewalks Electrical Master Plan Township proclamations Air and water quality monitori
62 - IMIESA JULY 2011
M2 Hostel Phase 2 Mandela Yard and Interpretation Centre River Park Rental Rooms No 3 Square upgrading No 1 Square upgrade M2 Hostel Phase 3 Football for Hope – Minerva M1 Hostel Phase 1 Helen Joseph Phase 1 Alexandra Ext 31 BNG Flats Marlboro BNG Flats Phase 2 Erven 44 & 45 Far East Bank Lombardy West BNG Flats Linbro Park bulk services Phase 1 Iphuteng School Cluster grounds upgrading
mal settlements, it is obvious that huge progress is being made in Alexandra. In fact, urban renewal projects are being undertaken at various municipalities across SA, with millions being earmarked for the central business district of Mdantsane in the Eastern Cape (one of the largest townships in SA). A press statement issued in April 2011 revealed that Mdantsane will undergo a R128 million makeover as part of the Buffalo City Municipality’s Mdantsane Urban Renewal Programme, which seeks to breathe new life into ageing infrastructure and dilapidated social facilities in the township. The funds will be spent over the next five to 10 years in an effort to boost the area economically. The municipality’s engineering department has already identified infrastructure capacity constraints, particularly the sanitation ser vices, which need to be upgraded, and the land acquisition process has already begun. This project, like the ARP, is in keeping with the city’s aim to build infrastructure that will boost economic and social development and create sustainable development within the area.
AGEING INFRATRUCTURE
Geared up to reduce water losses
SA’s #1
in optimising municipal water distribution networks
The Central Business District of KwaDukuza’s replacement of 13.5 km of ageing water pipes has been completed within the R18 million budget.
T
HE AGEING WATER PIPES contract is the first phase in the iLembe District Municipality’s five-year plan to reduce leaks and align itself with the target set by the Department of Water Affairs. As part of the initiative, 11 new pressure reduction valves have been installed to control water pressure, which is saving 2.2 million kilolitres per day. iLembe mayor, Welcome Mdabe, expressed his gratitude to everyone for their patience during the construction. “Now that the new system is up and running, there will be massive water savings based on the leaks experienced with
the aged infrastructure which we found during this project,” he continued. The new PVC system, with piping ranging in diameter from 50 mm to 200 mm, will provide iLembe with a reliable supply of water, in contrast to the previous situation of leaking pipes and interruptions to water supplies. According to Mayor Mdabe, all savings will be reinvested to improve service delivery in adjoining areas as the project is now moving Siphelele Ntuli, a Grade 6 pupil at New Guelderland School, drinks water from a running tap at his school
Head office Tel: +27 (0)31 700 1177 Fax: +27 (0)31 700 9853 For further information please visit
www.joat.co.za
AGEING INFRASTRUCTURE into Mandini. The next phase of the contract will be to replace a further 5 km of water pipes in the KwaDukuza central business district (CBD), as well as 4.5 km of water mains in Mandini. Water is a scarce resource, particularly in the iLembe District. While the municipality is boosting water supply, people need to use water responsibility. During 2011, a training programme that was introduced as part of the district’s turnaround strategy has taught people to use water responsibly in order to prevent future shortages and restrictions. Posters endorsing training, and reiterating the key message: Water is life, are displayed throughout the district. Mdabe continues: “Knowledge is power and this is our way of empowering the community. iLembe District Municipality is committed to providing potable water to the people and in turn our people must form a partnership with us and learn how to use water responsibly.”
ABOVE A total of 11 new pressure reduction valves have been installed to control water pressure, saving 2.2 million kilolitres per day LEFT Work in progress KwaDakuza
By 2015, iLembe’s target is to reduce leakages from 48% to 25%, which aligns itself with the target set by the Department of Water Affairs. iLembe District Municipality situated about 65 km north of Durban, is endowed with wealth of rich historical and cultural history. KwaDukuza is the reincarnation of the Royal Homestead and head quarters of His Majesty King Shaka KaSenzangakhona – a shrewd leader and strategist whose leadership attributes and vision was years ahead of his time.
INDEX TO ADVERTISERS Aurecon Group
27
ERWAT
16
OMB Waste Logistics
Aveng Manufacturing
IBC
GeoZone GeoService
41
RLH International
Barloworld Equipment
42
OFC & 32
Incledon
52
Engineering Consultants
26
Bell Equipment
60
Infropex
36
Rocla
55
Bigen Africa
44
ITT Water & Wastewater
20
SBS Systems
12
Bosun Brick
11
Jeffares & Green
13
Sembcorp Silulumanzi
BVI Consulting Engineers
37
Jetvac South Africa
59
Sensus
10
Cement & Concrete Institute
40
Joat Group
63
Swans Water Treatment
30
Centre of Environmental Management
61
Krohne South Africa
14
Thuthuka Group Limited
33
City of Cape Town
28
Lektratek Water Technology
18
Trenchless Technologies
IFC
Concrete Manufacturers Association
15
Meissner
22
UWP Consulting
Databuild
54
Namakwaland Konstruksie
47
Water & Sanitation Services
39
WILO South Africa
58
Zest WEG Group
57
Veolia Water
24
Durban Instruments Specialists
2
National Asphalt
ELB Equipment Limited
56
No Dig SA (Westrade Group)
Empowerisk Management Services
51
Nolada 8
64 - IMIESA JULY 2011
Loose insert 31
4
35 OBC
250 000 metres of
TRENCHLESS PIPE Successfully Installed
RENOVATE EXISTING PIPES BY: 1JQF #VSTUJOH t 4MJQMJOJOH t $*11 67 $VSF t $*11 "NCJFOU $VSF 3JCMPD &YQBOEB t 3JCMPD 3JCMJOF t 3JCMPD 3PUPMPD t 1JQF &BUJOH INSTALLATION OF NEW PIPES BY: )PSJ[POUBM %JSFDUJPOBM %SJMMJOH t (VJEFE 3PDL %SJMMJOH t #PSFT PG NN -FOHUIT VQ UP NFUSFT t .JDSPUVOOFMMJOH
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