One of Indah Water's vital services is refurbishment. The rehabilitation work on existing plants with same capacity and/or treatment processes will enhance the effectiveness and efficiency of such plants in addition to improving the aesthetics. The process entails fairly-complex works ranging from civil engineering aspects of safety, security, cleanliness and aesthetics, to the highly-complex skilled mechanical and electrical serviceability of the plants. Currently, over 5,408 public sewage treatment plants and pump stations are undergoing total refurbishment.

Refurbishment work involves the tidying up of treatment plants and pump stations with improved aesthetics and security; the repairing, replacing and testing of pumps, float switches and associated valves and pipeworks; the repairing, replacing and testing of treatment process equipment; the desludging of plants including holding tanks; the repairing, replacing and testing of High Voltage and Low Voltage electrical services including electrical wiring, control panels, lightning protection, etc; the sampling of effluents to ensure applicable environmental standards are met; and the inspection, repairing and/or replacement of critical sewer pipework. 

It takes anywhere between three to 24 months to refurbish a plant. 

Assuming one plant is fully refurbished in a day, it would take over 14 years to refurbish all of Malaysia's public sewage treatment plants. However, Indah Water aims to complete all refurbishment on a priority basis within six years. 

Most treatment plants handed over to Indah Water were found to be totally neglected and posed safety and environment hazards. 

A number of plants were found to be inaccessible for maintenance due to overgrown vegetation. This contributed to the non-performance of the treatment plants. 

A view of an Imhoff Tank before and after refurbishment. Note the safety features incorporated to prevent unwanted accidents 

A view of a sewage treatment plant that had undergone total refurbishment. 

Tidying up of treatment plants with improved aesthetics and security