Leading black-owned contractor Concor is over halfway with extending the continuous ash disposal facility (ADF) at Eskom\u2019s Majuba power station near Amersfoort in Mpumalanga. This project will ensure that Majuba can continue generating electricity while complying with ever-stricter environmental regulations regarding the responsible storage of waste.<\/p>\n\n\n\n
According to Mabandla Dlamini, contracts director at Concor, the extended ADF will accommodate ongoing ash generation at the power station until February 2036. The project is being conducted in a fully-integrated joint venture with Midrand-based contractor Lubocon Civils, with an 85%:15% split with Concor holding the major percentage.<\/p>\n\n\n\n
To date, Concor has handed over Terrace 2A and is in the process of handing over one of the two rehabilitation dams, says Dlamini. The construction of the extensive terraces \u2013 which measure 1.2 km long by 175 metres wide \u2013 began with bulk earthworks, cutting down to a design level before constructing the various layers. <\/p>\n\n\n\n
These layers include 100 mm of filter sand, followed by a Class 2 geomembrane and two 150 mm layers of clay. This is covered by a double-textured 1.5 mm HDPE geomembrane, followed by a 300 mm coarse ash layer. Each liner terrace, constructed from stabilised ash, is broken down into compartments of 5 metre widths, located every 100 metres.<\/p>\n\n\n\n
\u201cUnderneath these layers, we are constructing a network of herringbone subsoil drains with a leachate collection system which will flow into a pollution control dam,\u201d Dlamini says. \u201cThis will drain into Pollution Control Dam 5.\u201d<\/p>\n\n\n\n
Specialist sub-contractors have been used for the all-important lining beneath the dams, as well as the identification of any potential leaks in this lining. <\/p>\n\n\n\n
\u201cThe excavation and bulk earthworks for the pollution control and rehabilitation dams is followed by the construction of a subsoil drainage layer,\u201d he says. \u201cIn addition to the geomembranes and layers of filter sand and impermeable clay, this layering includes 250 mm thick geocells, a ballast layer comprising 300 mm thick cement-stabilised sand (8% by mass) and geocells.\u201d<\/p>\n\n\n\n
The rehabilitation dams also have penstocks and valve chambers. Enhancing the environmental controls are water perimeter canals around the whole facility to separate and channel clean and dirty water. These are lined with 100 mm geocells filled with 30 MPa concrete, controlling the stormwater in the area. <\/p>\n\n\n\n
\u201cThe canals play a vital role in reducing the risk of any washdown from the tailings facility,\u201d he says. \u201cMeasuring up to 7 metres in width, the total combined length of these canals will amount to more than 4 km.\u201d<\/p>\n\n\n\n
Some 1,400,000 m3<\/sup> of earth is being excavated during the project, while the linings include 860,000 m2<\/sup> of double-textured 1.5 mm high-density polyethylene (HDPE) liner. The stabilised ash layer will require 130,000 m3<\/sup> of ash sourced from the power station and screened to prescribed specifications before being mixed with stabilising cement.<\/p>\n\n\n\n For the concrete work \u2013 which will include structural concrete for silt traps, spillways, drains and culverts bases \u2013 a total volume of 14,000 m3<\/sup> of concrete will be used. Some 7,700 tonnes of cement will be delivered in bulk, to be stored in Concor\u2019s on-site silos at its batch plant.<\/p>\n\n\n\n Site agent, Muhammad Asmal says that at project peak there will be almost 90 items of earthmoving equipment on the site. This will include 40-tonne articulated dump trucks, 70-tonne tracked excavators, tipper trucks, pug mills, screening equipment, graders and compaction equipment. <\/p>\n\n\n\n \u201cThere are 43 subcontractors and suppliers engaged in the project,\u201d Asmal says, \u201cwith over 440 personnel employed on site \u2013 285 of them from local areas.\u201d<\/p>\n\n\n\n The Concor-Lubocon JV is also constructing 5.5 km of internal or monitoring road, with G5 and G7 layers from commercial sources in Newcastle and Ermelo respectively. <\/p>\n\n\n\n \u201cAs part of Eskom\u2019s commitment to supplier development and localisation, a Supplier Development Plan was developed in conjunction with the Concor Lubocon JV to facilitate the inclusion of SMEs and QSEs from various towns surrounding the Majuba power station,\u201d Nielesh Maistry, Eskom projects manager, says. \u201cThis included areas in the Gert Sibanda Municipality. \u201c<\/p>\n\n\n\n SD&L manager, Nkateko Rasimphi highlights that the Concor Lubocon JV takes a proactive role in the training and induction of small and medium-sized enterprises (SME), especially with regard to issues such as legal liability, hazard identification and risk assessment.<\/p>\n\n\n\n \u201cWe have identified local technicians who we will help to develop, with the objective of training them and putting them on the road to professional registration,\u201d he says. \u201cThe JV also runs a corporate social investment programme with local communities, focused on educational infrastructure in previously disadvantaged schools.\u201d<\/p>\n\n\n\n Complying with strict environmental regulations means ongoing monitoring on site, according to Portia Rasakana, Lubocon\u2019s environmental manager at the Majuba project. She highlights waste management as a key focus to avoid any environmental impact, but concerns such as pollution and dust management also receive constant attention.<\/p>\n\n\n\n \u201cIt is crucial that all our employees and subcontractors are conversant with the conditions of our Environmental Management Programme and our Water Use Licence,\u201d says Rasakana. \u201cThis means building awareness among all our partners, and following up with strict enforcement.\u201d<\/p>\n\n\n\n She notes that alien vegetation is also a concern, especially in areas where ground is disturbed. Management plans are in place for all environmental issues including waste, water and hazardous materials, she says. <\/p>\n","protected":false},"excerpt":{"rendered":" Leading black-owned contractor Concor is over halfway with extending the continuous ash disposal facility (ADF) at Eskom\u2019s Majuba power station near Amersfoort in Mpumalanga. This project will ensure that Majuba can continue generating electricity while complying with ever-stricter environmental regulations regarding the responsible storage of waste. According to Mabandla Dlamini, contracts director at Concor, the … Continue reading CONCOR PROGRESSES WITH MAJUBA ASH DISPOSAL FACILITY<\/span>