With seven million people to cater for in Hong Kong, the local Water Supplies Department (WSD) has stepped up to the mark to ensure the delivery of a safe water supply, with significant investment over the past decade.
“It is always a prime objective in our mind to ensure the provision of a reliable and clean water supply for some 7 million people in Hong Kong, quietly supporting the economy and prosperous development of society.
“You will notice from the water quality data publicized that the quality of our drinking water has for years been among the best in the world. However, while water is taken as a matter of course in the daily routine of people here in Hong Kong, we will try to arouse their awareness of the value of water, in a world in which this vital resource is rapidly diminishing, and make known the importance of water conservation by conducting publicity campaigns, states Mr. Enoch LAM Tin Sing, JP, Director of Water Supplies.
The main functions and services of the Department include the planning and management of water resources and water supply systems.
To that end, the department plans water resources, prepares outline proposals for new water supply schemes and improvements to the existing system to meet growth of demand in existing and developing areas, monitors the adequacy of water resources and installations and collates hydrological information necessary for the management and development of the waterworks.
The Department also designs and constructs waterworks projects, including catchwater, tunnels, reservoirs, water treatment works, access roads, pumping stations and pipeworks. Specialist works such as laying of submarine pipeline, dam construction and major water supply projects are usually undertaken by consulting engineers. The Consultants Management Division will vet and approve consultant’s proposals and monitor and administer work and agreement.
Additionally, the Department operates and maintains water supply and distribution systems, monitoring water storage, operation and maintenance of catchwater, intakes, impounding reservoirs, pumping stations, water treatment works, service reservoirs, trunk and distribution mains to ensure a reliable water supply to the customers.
Work also involves checking and controlling the quality of water supplied. The Department regularly carries out chemical, bacteriological, limnological, biological and radiological examination of samples taken from raw, treated and customer tap sources.
Investment is of course an important aspect for any company to sustain a safe and reliable source of clean water.
The Water Supplies Department has invested significantly in the construction of the Tued Mun Water Treatment Works (WTW), as the company website explains:
“With an extraordinary innovative effort, team spirit and special considerations of local geographic landscapes, the WSD built Hong Kong’s first hydropower plant at the Tuen Mun Water Treatment Works (WTW), adopting and utilising renewable energy as well as protecting the environment.
“Due to the rapid population growth in the New Territories West and Lantau Island in recent years, a higher water level has to be maintained in Tai Lam Chung Reservoir to ensure a stable supply of water to its associated WTW.
“This leads to a sustained high pressure on the inlet valves of the Inlet Reception Tank at the Tuen Mun WTW, which accelerated their normal wear and tear and necessitated more frequent maintenance.
“The WSD turned this problem into an opportunity and installed two hydropower turbine generators at the WTW. Water from the Reservoir is first diverted to the generators before entering the Tank, thereby transforming the residual water pressure energy into electricity and greatly alleviating the wear and tear problems of the valves. In addition to reducing maintenance costs for the valves, the use of the generators saves the WTW an electricity consumption of about 3 million kWh and reduces 2,000 tonnes of carbon dioxide emissions annually.
“The hydropower plant at the Tuen Mun WTW is the first of its kind in Hong Kong. Due to the lack of precedents, the design and construction processes met many obstacles. With regard to the mechanical and electrical equipment, most turbine generators available in the market are only suitable for dams or rivers, but, after many rounds of research and evaluation with a partner pump manufacturer, the WSD found a special kind of turbine generator. In addition, due to the limited available space of the WTW, only an area of about 10 metres by 12 metres could be made available for constructing the hydropower plant. Therefore, the team had to resort to multi-level design for the plant, and install the equipment in two storeys in order to make the most of the limited space.” (751 words)
Another major project has been the expansion of the Tai Po Water Treatment Works.
Completion of the Tai Po expansion, set to double the capacity of the plant, on Hong Kong’s east coast, is scheduled for mid-2017. The facility will be able to take up part of the Sha Tin Water Treatment Works’ load in supplying fresh water to a significant part of Kowloon and the Central and Western districts on Hong Kong Island.
Tai Po Water Treatment Works, commissioned in 2003, presently has a capacity of 250,000 cubic metres per day with provision for expansion to 1,200,000 cubic metres per day. It will become the second largest treatment works in Hong Kong when the ultimate stage is commissioned in future.
Black & Veatch partnered with the department on this large expansion project at the Tai Po Water Treatment Works.
As a result, the Tai Po Water Treatment Works is now an innovative and essential part of the area’s water infrastructure. Black & Veatch designed and oversaw construction of the project which more than triples the capacity of the water treatment works, providing up to 800-million-liters-per-day of reliable water supply to the people of Hong Kong. In addition, the Water Supplies Department estimates this project created approximately 2,100 jobs in the local construction industry.
The ability to supply clean water will remain and ongoing task of maintenance and investment, as the WSD looks to the long-term future for the residents of Hong Kong.