Towards the end of 2011, residents of Ballito experienced near-constant water shortages.
“The bulk water supplier to the area, Umgeni Water, then appointed Icon Construction to construct the 10.8 km 700 mm diameter pipeline from Hazelmere Water Treatment Works (WTW) to La Mercy Bifurcation,” explains Darren van Rooyen, design engineer from Royal HaskoningDHV. The R56 million pipeline project was completed in November 2013. “All the challenges experienced during the pipeline contract were overcome,” explains Peter Hope, Icon Construction’s commercial manager.“The ubiquitous landowner and wayleave issues were resolved by the team. The pipejack below the Ndwedwe Road and oil pipeline were extremely difficult and took several weeks longer than anticipated to complete, and this nearly caused a significant delay to the project. The expediting of the steel pipe supply by Group Five Pipe, by some eight weeks, was critical – the first pipe was on site in the tenth week of the contract period (mid-April) and 95% was laid by the end of August.” The success of the project was in large part dependent on the ability of the suppliers to keep to a regimented delivery regime. This ensured that deliveries were coordinated with production rates of the pipe-laying crews at the time. The steel pipe used contained a 6 mm thick polyurethane coating and also featured a cement mortar lining. The bulk of the pipeline was constructed through rural sugarcane plantations and a small section cut through an urban area. The initial clearing of the alignment was undertaken with 20 t excavators with tractor-loader backhoes used to carry material from the site. Pipes were then offloaded and strung alongside the trench before being placed in the trench with side boom pipe-layers. Following the root welding to the inside of the pipe joints, the welding team undertook the fill and cap on the outside. The welded pipe joints were then X-rayed to make sure they were free of defects before being tape-wrapped.They were also examined to ensure there were no gaps in the cement-mortar lining inside the pipeline. Once the engineers were satisfied with the quality of the pipeline, backfilling began. At a river crossing, Icon Construction encountered challenging wet ground conditions. This required modification to the river sand pipeline bedding used for the rest of the pipeline. In these sections, the pipe is encased in concrete and laid on stone bedding wrapped in geo-fabric material to strengthen the poor founding material. While the bulk of the pipeline was laid using conventional trenching methodologies, two crossings called for the deployment of trenchless techniques. The pipeline servitude required crossing of both a road and railway line, resulting in pipe-jacking being subcontracted to Esorfranki. An interesting aspect of the project was the subcontracting of all the environmental and rehabilitation aspects of the endeavour to a specialist. The use of Greenbelt Mapping services, which included background work before the project began, enabled the project participants to focus on critical aspects of the construction programme. This resulted in massive time-saving advantages for the consultant. “Following the completion of thispipeline contract,Umgeni Water has now also awarded a contract for the upgrading of the Hazelmere WTW and a contract for the new pump station to supply the La Mercy Reservoir.These combined projects are scheduled for completion in October 2013 and will meet the medium-term demands until the uThukela Bulk Water Supply System is operational, explains Xolani Chamane, Umgeni Water’s project manager.
The project team
Employer: Umgeni Water Project manager:XolaniChamane Engineers: Royal HaskoningDHV Surveyor: JC Martin Surveys Cathodic protection consultants: PPT Health and safety consultants: Intervention Systems Contractor: Icon Construction Pipejackack subcontractor:Esorfranki Geotechnical Environmental rehabilitation specialist: Greenbelt Mapping
