6 ML CONCRETE RESERVOIR AT RUSTENBURG PLANT FOR GLENCORE

Glencore proposed to construct a new 6 ML concrete reservoir complete with pumphouse and steel cladded roof at their Rustenburg plant.

The reservoir was required to store surplus water for their operations to alleviate ad-hoc water shortages from inconsistent municipal sources.

Project Overview

The Scope of Work covered under this Contract was as follows:

1. Contract Value: R 12 994 340.62
2. Contract Duration: 8 months

1. The Civil Works will consist of a reinforced shuttered concrete reservoir: 40m x 30m x 5m high with a pump chamber.
2. Minor Earthworks consisting of importing 750m3 approved G5 material from the stockpile on site and compact it to falls and levels of 1400m2. Excavations for sumps; retaining wall foundations; and for the subsoil drains.

1. Concrete works will consist of the shuttering of the floor slabs, and the surface bed cast to falls with 30 MPA concrete that contains waterproofing admixture agents.

Smooth formwork of 1400m2 will be required to a maximum height of 5 metres complete with a safe access walkway and staircase. Reinforcing of 85 tonnes will be installed, with 220 m3 of concrete cast to the walls.

1. The concrete reservoir and pump chamber will be covered with a hot dipped galvanised portal frame steel structure and Chromodek IBR sheeted roof complete with ridge mounted ventilators and flashings.

1. Mechanical and Electrical installation consisting of electrical supply to the pump chamber; supply and installation of water pipes; supply and installation of pumps and motors onto concrete plinths; and the supply and installation of valves.

Construction of the Crown Gardens Water Tower and Pump Station

Project Overview

1. Contract Value: R 66 076 210.99

The Scope of Work covered under this Contract was as follows:

• The construction of a 2,0Ml concrete water tower, 20,8mØ x 6,3m high on a 22m high concrete support structure, similar to the existing tower on the site.
• The construction of a new pump house and the refurbishment of existing pump house into a generator room.
• The supply and installation of new pumps and new switch gear in the new pump house.
• The supply of new mild steel pipes ranging from 225mmØ to 600mmØ to connect the new tower and pump house with existing pipelines.
• The removal existing palisade fence and replacement with a Clearvu steel fence, including a new entrance gate and the construction of a new guard house.
• The construction of access road and pavings on site.
• Construction of storm water drainage system.
• Upgrading of existing electricity supply to feed the new pump station.
• Supply and installation of a stand-by generator.
• Upgrading of existing telemetry system to include the new works.
• After completion of the new works, rehabilitation of the existing tower.

The project was put out on tender during 2018 and was awarded to Esor Construction. The Site was handed over to Esor in October 2018 with due completion date in July 2020. However, the Covid-19 epidemic hit the world in March 2020. Apart from construction time lost, the supply of specialist equipment like, closing valves, had a detrimental effect on the programme of the project, and the work was only completed in October 2021.

Challenges faced on the project and the implemented solutions

The fact that the reservoir and the existing tower had to remain in use throughout the construction period, posed a challenge throughout the construction period. The first challenge was the removal of existing services, such as the electrical connection to the pump station and a water pipe, within the footprint of the new tower. This delayed the excavations for the new tower by about 2 months. Another five shutdowns were required during construction period. Careful planning and coordination were required for every shutdown.

Existing pipes were installed in the early 1950’s. Although the old pipes were still in very good condition, outside diameters differed from new pipe diameters and special stepped adaptors had to manufactured to join old and new pipes.

Community upliftment

Joburg Water stipulated in the contract conditions that 30% of the contract value must be outsourced to SMME’s. The following items were identified for possible outsourcing:

• Storm water drainage and road works
• Steel fixing
• Erection of scaffolding and shuttering
• Security fencing
• Brickwork

The Contractor was fortunate to find suitably experienced sub-contractors to carry these work items. These sub-contractors employed local labourers and the community benefitted from the project through this financial boost.