The Heidelberg WCW is situated south of Heidelberg and falls within the DD5 drainage district. Built in 1963, and upgraded and extended on several occasions over a period of time, the designed capacity of the works is 5.4 Mℓ/d of industrial effluent and raw sewage from the Heidelberg areas. Activated sludge is employed as the main treatment process.

A central inlet works, incorporating the process of screening and grit removal, serves the works. The activated sludge process includes primary sedimentation, a three stage BNR activated sludge reactor basin and final clarification. The final effluent is chlorinated before it is discharged into the Blesbokspruit.