Existing Used Water Infrastructure
The last few decades have seen the rapid development of used water infrastructure to serve a growing Singapore with expansion of the used water network. Today, Singapore boasts a world class sewerage system in which 100% of the population (45% in 1965), is served by modern sanitation. Used water from designated catchments is treated at the 5 water reclamation plants using the activated sludge process
As water is a very scarce resource in Singapore, it is our interest to conserve every drop of water and reclaim water from used water. The latter led to the production of industrial water and NEWater.
The Jurong Industrial Water Works was constructed in 1966 to further treat the final effluent from WRPs to produce industrial water (IW) for use by industries. The main uses of IW are for cooling, washing and further treatment to higher grade IW. Currently, the plant produces 73,000 cu m/day of IW. Since Jan 2007, 23,000 cu m/day of IW is also being produced by the Membrane Bioreactor Plant at Ulu Pandan Water Reclamation Plant.
Recent developments in used water purification technology have enabled used water effluent to be treated to even higher standards than IW, known as NEWater. NEWater is suitable for use by industries requiring high grade water, e.g. wafer fabrication plants.
Covering of Water Reclamation Plants (WRPs)
In the 1990s, PUB implemented the plans to cover up the existing water reclamation plants and install odour control facilities to reduce the surrounding odour buffer zones. This freed up more land for higher value development. The covering of the existing treatment units at Kranji, Ulu Pandan, Seletar and Bedok WRPs were completed towards the end of the decade. Bedok WRP was subsequently decommissioned in Mar 09.
Concurrently, extensions for Kranji WRP, Ulu Pandan WRP and Seletar WRP were carried out using the compact and covered design concept and were completed in 1999, 2000 and 2001 respectively. In the compact and covered design, various treatment units and tanks are constructed close to one another with common walls and are roofed over with a concrete slab. Less land is required for such plants. The foul air is then extracted for treatment before discharging into the atmosphere.
Comprehensive odour control facilities comprising odour containment covers over the treatment units, extensive odorous air extraction systems and odour treatment plants are introduced to contain and treat foul air from covered treatment units. The ambience of the plant is improved and odour nuisance is minimised. Odorous air is extracted and passed through a 2-stage treatment process beginning with chemical scrubbing and followed by activated carbon adsorption before discharge into the atmosphere. With the odour control systems in place, the odour buffer zone around the WRP is reduced and more land can be released for higher value developments.