18 November 2010 - Every two years, the Institute of Municipal Engineering of Southern Africa (IMESA) invites local, provincial and government/semi-government authorities and/or their engineering consultants to submit entries for the IMESA Biennial Project Excellence Awards.

Entries are required to demonstrate ‘the art and science of infrastructure engineering to the general public and indicate how the profession finds answers to challenges’.

This year, Aurecon and SSI Consulting and Environmental Engineers’ project, titled ‘Emergency re-use of treated effluent for the George Municipality’, won the award for the best Community Upliftment project in South Africa.

A key criterion for this category was the project’s response to community needs. “Because the project helped secure a sustainable and safe water supply for the citizens of the George Municipality, it was a perfect candidate,” comments Aurecon Water Sector Leader, Professor Andre Görgens.

George has a historical annual average rainfall of 712.3 mm, but only received an average of 375 mm in 2009, plunging the area into severe drought. This prompted the City of George to take a decision to implement a scheme for the indirect re-use of treated effluent. This scheme, which forms part of the Municipality’s Raw Water Augmentation Plan drawn up in 2005 by Aurecon, will ensure a sustainable supply of raw water to meet potable water demands within the George Municipal area.

The initially proposed bulk water augmentation schemes included:

• A pumping scheme on the Kaaimans River that transfers water from the Kaaimans River and discharges it into the Garden Route Dam (implementation was completed in 2008)
• The Malgas River Pumping Scheme (MRPS) and the raising of the Garden Route Dam spillway (implementation commenced in 2009, with completion expected in 2011)
• Construction of the Malgas/Maalgate Dam (implementation will be based on growth and demand in the city of George)
• The indirect re-use of treated effluent, which was completed as an Emergency scheme (2009/2010) due to the severe drought in the region

Aurecon and SSI were appointed by the George Municipality to undertake the necessary design, formulation of tender documents for the construction phase and overall monitoring of the construction works for the indirect re-use of treated effluent scheme.

Initially, the project will add 10 Ml/d to the Garden Route Dam. Later, this can potentially be expanded to 35 Ml/d by incorporating a further 10 Ml per day of effluent from the Gwaiing Wastewater Treatment Works (WWTW) and an additional 15 Ml effluent per day from the future upgrading of the Outeniqua WWTW.

“From a resource perspective, the indirect re-use of treated effluent is not only environmentally sustainable, but economically sustainable as well, as water that has already been collected from natural raw water resources can be re-used, without the need to develop new natural resources. Water can be continually recycled safely and blended with the new natural raw water to reduce the demand on the other natural water resources,” explains Professor Görgens.

He goes on to conclude that it is projects such as these that demonstrate the engineering profession’s ability to solve the most pressing challenges that today’s communities face.