New Sewage Treatment Works at Orapa Mine, Botswana

Aurecon provided design and construction services for new sludge sewage treatment works with a capacity of 3.5 ML/day at Debswana’s open-cast mine in Orapa. The works replaced the existing facility that was made redundant by expansion of open-cast operations at the mine. 

Aurecon’s role included the design and construction of the biological reactor. In addition, Aurecon undertook the process and hydraulic design, topographical and geotechnical investigations, structural and civil design, mechanical and electrical services design, compilation of tender documentation, construction supervision, and the eventual commissioning of the works.

The design included two sludge lagoons where waste sludge is discharged for stabilisation and settling, with the supernatant water then being used for irrigation of parks. Another design element was an emergency storage dam where excessive flow can be diverted for gradual inclusion into the influent for treatment.