13 November 2015 - Aurecon recently walked away with one of the construction industry’s most coveted accolades at the 2015 Construction World Best Projects awards for its involvement in the pioneering Preekstoel Water Treatment Works (WTW) project.
Initiated in 2002 and held annually thereafter, the externally-judged ‘Best Projects’ competition is hosted by Construction World magazine. The awards aim to showcase excellence in the South African building, civil engineering and project management sectors.
The Preekstoel WTW was named the ‘Overall Winner’ in the Professional Services category. However, this was not the first time that the project had earned a prestigious award. In 2014, the Preekstoel WTW was announced the winner in the category for Water and Wastewater at the 78th Institute of Municipal Engineering of Southern Africa (IMESA) Biennial Project Excellence Awards, held in eThekwini.
“The Preekstoel biofiltration plant is the first full-scale plant of its kind in South Africa employing a natural process, which is acknowledged as being far more environmentally friendly, requiring fewer chemicals, saves on electricity and reduces water loss in the treatment process,” says Hendrik Honey, Project Director for the Preekstoel WTW.
Honey further explains that Preekstoel WTW treats water from a series of groundwater well fields to supplement the surface water being sourced from De Bos Dam, the main water source for the Greater Hermanus area. Water requirements of the Overstrand Municipality necessitated the treatment of the various well fields to be integrated, and a tailored process designed to ensure reliable achievement of target water quality. A new project was therefore implemented to increase the water supply and treatment capacity of the Preekstoel WTW. Aurecon was appointed to provide water and wastewater treatment services for this important upgrade project.
Work on the project commenced in 2010, with new plant and infrastructure being commissioned in stages from early 2013 onwards. A biological plant was constructed adjacent to the existing plant at the Preekstoel WTW for treating a maximum of 10 Ml/day borehole water. The groundwater being pumped is rich in iron and manganese, which must be removed to prevent problems, ranging from the staining of fabrics to the clogging of the water distribution network with gelatinous bacterial organisms that use iron and manganese in their metabolism.
“After an extensive period of monitoring and tweaking, the biology had established sufficiently to deliver treated water meeting the SANS 241:2011 quality requirements of such a plant,” says Honey.
Exceptional attention to plant design, construction and finishing, together with innovative solutions to environmental protection needs, has resulted in a facility that will cater for the growing water demand of the Greater Hermanus area well into the future, especially during peak holiday periods.
Since completion, the Preekstoel WTW project has provided a cost-effective and innovative means of securing the Greater Hermanus water supply requirements, while simultaneously protecting the area against future droughts.