Wastewater Project of the Year
Changi WRP Expansion, Singapore
What is it?
A 200,000m3/d (peak 300,000m3/d) expansion to the Changi Water Reclamation Plant, one of the largest and most advanced water recycling facilities in the world. The expansion was delivered through the addition of a fifth treatment train and separate wet weather treatment facility (WWTF) at the facility, which treats wastewater to a standard where it can be further processed to create NEWater, the purified water source that forms one of Singapore’s four National Taps.
Who is involved?
Singapore PUB, which was supported in study design and delivery supervision by consultant Jacobs. Construction work on the project was led by HSL Constructor. Other key contractors included Quek & Quek, Koh Brothers and CES_Salcon (civil and construction engineering) as well as Memiontec and Veolia (WWTF installation).
What makes it special?
The use of one of the world’s largest MBR systems as an initial stage before NEWater treatment (in place of the traditional activated sludge) provides a purer feedwater, increasing reverse osmosis membrane lifespan and reducing fouling and sludge production. The size of the MBR installation allows for the future delivery of more NEWater capacity as the city-state looks to expand its water supply.
By overdesigning the capacity of treatment stages the plant future-proofs itself against increasing demand and storm surges. The MBR system can handle a peak 300,000m3/d while another 200,000m3/d can be treated by the WWTF and mixed with effluent from existing facilities to be safely discharged into the sea during extreme weather events.
A challenging but innovative siting approach where process tanks are all underground and treatment infrastructure on the floor above met local height restrictions and integrated with the existing inflow infrastructure. Despite the sea-level location, the lowering requirements were met ably, leaving space on the roof for the construction of future NEWater facilities.
Distinction
Umm Al Hayman WWTP, Kuwait
What is it?
A 500,000m3/d privately owned plant, treating wastewater from the southern part of Kuwait and supplying treated sewage effluent (TSE) for agricultural use. The treatment plant uses a standard secondary treatment approach followed by cloth filters, UV and chloringe disinfection as well as extensive sludge management elements to serve a population equivalent of around 1.7 million, and the scope of the project also included a 450km wastewater and TSE network, pumping stations, treated effluent reservoirs, biogas production and a 6km emergency sea outlet.
Who is involved?
Umm Al Hayman was delivered on a 25-year build-operate-transfer basis by a team comprising WTE Wassertechnik and International Financial Advisors. WTE was also the lead EPC contractor for the project. The client for the project was Kuwait’s Ministry of Public Works. Siemens supplied WTE with equipment and engineering services for automoation and electrification.
What makes it special?
As a breakthrough project combining wastewater collection, treatment, TSE distribution and sludge management, Umm Al Hayman is the perfect example of the private sector offering a “one-stop-shop” solution to wastewater issues. The widespread scope of the project and the decision to bundle in network elements to the treatment contract means Kuwait’s sanitation and reuse ambitions have been transformed at a stroke.
By acting as a massive centre for treatment and water reuse, the project is set to solve the perennial issue of overflows of raw sewage into the Gulf, a regular occurrence in the past and one that threatened the coastal environment and seawater composition.
The site offers a model for sludge management in a region that has often been relatively slow to embrace the benefits. Around 120,000 wet tonnes of sludge will be processed per day, creating a valuable source of composting material for agricultural us, while the generation of biogas through digestion creates a valuable source of internal energy that can power a significant portion of the plant’s overall power requirements.