Apart from conserving our drinking water, reclaimed water reduces the amount of treated effluent that is discharged into the aquatic environment. In line with experience around the world, reclaimed water could be used in the following ways.
- Cleansing roads and vehicles
- Irrigating parks and sport fields
- Flushing toilets
- Fire fighting
- Industrial production
- Urban development and landscaping
With these applications in mind, the Government has developed schemes to explore the possible uses of reclaimed water in Hong Kong.
At present, the “Reclaimed Water” schemes launched at the Ngong Ping Sewage Treatment Works and Sha Tin Sewage Treatment Works are the largest among other sewage treatment works to promote the use of reclaimed water.
The scheme at Ngong Ping was commissioned in 2006 when the Ngong Ping Sewage Treatment Works opened on Lantau Island. As the first tertiary treatment works in Hong Kong to produce reclaimed water, the Ngong Ping Sewage Treatment Works uses a sequencing batch reactor, dual media filter and disinfection process to reduce organic pollutants, suspended solids, nutrients and pathogenic organisms from sewage to a very low level. The reclaimed water produced is odourless and safe. It is currently used for toilet flushing in nearby public toilets and the Ngong Ping Cable Car Terminal, and also for rearing aquarium fishes and controlled irrigation inside the sewage treatment works.
The water reclamation facilities at the Sha Tin Sewage Treatment Works, which were commissioned in early 2011, comprise three filtration parts, namely disc filters, ultra-filtration membranes and reverse osmosis membranes. The water reclamation facilities can produce about 1,000 cubic metres of reclaimed water every day, mainly for irrigation of plants there and the dilution of chemicals required for the sewage treatment processes.
Water reclamation facilities at the Shek Wu Hui Sewage Treatment Works, Ngong Ping Sewage Treatment Works and Sha Tin Sewage Treatment Works are operating. Further information on reclaimed water.