The Challenge
Rahman Enclave, a residential development in Islamabad, needed a domestic sewage treatment solution that could run reliably without heavy ongoing technical oversight — a different priority than an industrial site with dedicated operations staff.
The Solution
Critical GREEN designed and established a two-stage treatment system: a UASB (Upflow Anaerobic Sludge Blanket) reactor handles the initial high-strength organic load, followed by a constructed wetland for biological polishing. This combination pairs the compact, energy-efficient pre-treatment capacity of an anaerobic reactor with the low-energy, low-maintenance operational profile of a nature-based wetland stage.
The Outcome
The completed system provides staged, reliable biological treatment for the development's domestic sewage — giving residents an energy-efficient, low-maintenance solution suited to a residential setting, with the UASB stage adding treatment capacity beyond what a wetland alone would provide.
