Marking its 30^th anniversary of serving the people of Hong Kong this year, the Drainage Services Department (DSD) remains committed to providing world-class wastewater treatment and stormwater drainage services. With the spirit of “being neither afraid of what is hard nor careless with what is easy”, we have been united in rising to challenges at work in a sincere manner. I trust that over the past 30 years, Hong Kong citizens have witnessed the effort we have put into introducing innovative technologies to enhance drainage infrastructure.

Utilising Renewable Energy Turning Waste into Energy

Deeply concerned about the impact of global climate change, the Government set up the Inter-departmental Working Group on Climate Change as early as 2007. Chaired by the Environment Bureau, the Working Group comprises representatives from 16 departments including DSD. To combat climate change by reducing greenhouse gas emissions, we have actively promoted the use of renewable energy and sought opportunities to turn waste into energy.

The renewable energy currently adopted by DSD includes hydropower, solar power, and biogas. Taking Stonecutters Island Sewage Treatment Works (STW) as an example, in October 2018, we installed a hydro-turbine system at the plant for the first time, converting the flow of sewage into electricity, which was expected to generate up to 120,000 kilowatt-hours of electricity per year. Furthermore, we have installed solar panels in the open space of numerous sewage treatment facilities, with the solar farm at Siu Ho Wan STW being the largest solar photovoltaic system among government facilities and generating as much as 1.1 million kilowatt-hours of electricity annually. We are also proactively utilising biogas produced during the sewage sludge treatment process to generate electricity and heat, with biogas generators, boilers, etc. installed in major secondary sewage treatment works for converting biogas into electricity and heat. During the year, energy equivalent to about 27 million kilowatt-hours of electricity was generated from biogas, and DSD’s renewable energy facilities generated a total of over 28 million kilowatt-hours of electricity, which accounted for about 9% of DSD’s electricity consumption. In the future, DSD will continue to increase the use of renewable energy, with Hong Kong progressing towards a low carbon smart livable city.

In addition, we are carrying out a trial on food waste and sludge co-digestion technology at Tai Po STW to convert the biogas produced during the co-digestion process into electricity. We are actively implementing waste-to-energy measures and developing technologies applicable to DSD’s facilities, with a view to reducing dependency on conventional fossil fuels and easing pressure on landfills, thereby achieving sustainable development goals in the long run.

Co-use of Space

Since land resource in Hong King is scarce, drainage facilities inevitably become citizens’ close neighbours. With the spirit of “coexisting and sharing”, we connect drainage facilities with the community and build a close relationship with the public. We are now expanding Shek Wu Hui STW so that it will be turned into an effluent polishing plant of a tertiary treatment level. We will add to the plant “communion with the community” elements such as public open space and landscaped facilities which will be open to the public.

Challenges posed by Climate Change

Extreme weather brought about by climate change has become more and more obvious in recent years, affecting the global economic and social development. As a result, Hong Kong can hardly remain unscathed. When super typhoon “Mangkhut” struck Hong Kong in September 2018, record-breaking storm surges occurred in many districts, raising the water level generally by more than two metres, and leading to severe flooding in low-lying areas.

To meet the challenges posed by climate change, we have taken into account the previous records and identified seven Storm Surge Spots vulnerable to seawater inundation caused by storm surges as well as three Overtopping Wave Spots vulnerable to flooding caused by waves overtopping the seawall. Indeed, it is difficult for DSD to effectively tackle climate change alone. Thus, the Government and various sectors of the community (including enterprises) must work together to develop viable action plans in preparation for unexpected situations so that the flood risks at the locations concerned can be reduced as far as possible.

In the future, our team will continue to provide the public with efficient and quality sewage treatment and flood prevention services, and to explore with an open and pragmatic attitude the possibilities of introducing new technologies to better take forward our projects and operate our facilities so as to progress with the times. I hereby encourage all members of the Department to continue improving sewage treatment and stormwater drainage services wholeheartedly and diligently in this ever-changing era.

Kelvin LO Kwok-wah
Director of Drainage Services
December 2019