2011 Hybrid Bio-Retention System at Admiralty Park
Admiralty Park houses the largest nature area (20 hectares) within an urban park in Singapore. It is situated on a hilly terrain with a river, Sungei Cina, running through it. A hybrid bioretention system has been built to reduce the iron content of the influent, from nearest drain which can cause the water in the Admiralty Park pond to be an undesirable reddish color if untreated.
The hybrid system consists of a sedimentation basin, sand filter and a bioretention basin. After treatment in the hybrid system, the water quality of the effluent at the outlet of the system is greatly improved in comparison to the influent water.
Enviro Pro is involved in the design and build of the hybrid bioretention system.
Key Design Concepts:
Sedimentation basin – Promote the settlement of solids in the influent by reducing the velocity of the incoming water.
Sand filter – Water from sedimentation basin is fed to the surface of the sand filter, which then percolates down through the drainage layer. Solids are trapped at the surface of the filter, as well as within its pores.
Bioretention basin – The basin removes impurities in the influent water by fine filtration, adsorption and biological uptake by plants and microbes attached to plants roots within the cleansing layer. The basin also temporarily store stormwater runoff before conveyance to main public drains.