Infrastructure development takes considerable investment in time and money. In Hong Kong, the Drainage Service Department (DSD) has embarked on an ambitious project to improve the territories sewage system.
Industry-AP was privileged to speak recently with Edwin Tong Ka-hung, Director of Drainage Services.
Can you please provide me with an overview of the department’s core business operations?
“The vision of DSD is to provide world-class wastewater and stormwater drainage services enabling the sustainable development of Hong Kong.
“Sewage collection, treatment and discharge is one of the core service of DSD. Through a variety of sewage treatment processes and technological advances, we can remove most of the pollutants, toxins and bacteria from sewage. DSD strives to enhance both the efficiency and quality of our sewage treatment services, in order to safeguard the quality of Hong Kong waters.
“DSD operates 300 sewage treatment facilities and about 1 billion cubic metres of sewage was treated over the year, i.e. on average 2.8 million cubic metres per day.
“The public sewerage network runs 1,700 kilometres in length, serving around 93 per cent of Hong Kong’s population, while 393,000 tonnes of sludge were processed during the year.”
DSD currently manages a total of over 4,500 kilometres of underground drains and sewers. Many of them show signs of wear and tear and the company is responsible for monitoring the situation through regular inspection plans.
“Rehabilitation works will also be arranged when necessary. In 2015-16, we rehabilitated about 22 kilometres of drains and sewers at a cost of about $74 million,” Tong states.
The Professional Laboratory Services DSD operates multiple laboratories which provide professional and quality laboratory services, ensuring that sewage treatment processes meet the statutory requirements.
Since 1999, both Sha Tin Central Laboratory and Stonecutters Island Laboratory have been accredited under the Hong Kong Laboratory Accreditation Scheme (HOKLAS) operated by the Hong Kong Accreditation Services.
As a pilot scheme to automate our laboratories, in 2015- 16, an automatic Biochemical Oxygen Demand testing device was added, at Shatin Central Laboratory. During the year, 26 laboratory tests were accredited.
DSD runs more than 14 types of tests on a day-to-day basis: over 261,000 analyses were carried out in 2015-16.
When was the department established?
“The department was established in September 1989.”
How many people are employed by DSD?
“DSD consists of four branches with a staff establishment of 1,914.
“Our four branches comprise of:
“Revenue Tower – for headquarters, the Projects and Development Branch and part of the Operations and Maintenance Branch; Kowloon Government Offices – for the Operations and Maintenance Branch; Western Magistracy – for the Sewage Services Branch; and Shatin Sewage Treatment Works and Stonecutters Island Sewage Treatment Works – for the Electrical and Mechanical Branch.”
What has made the department so successful?
“The successful implementation of all the above work of DSD hinges on our mainstay – each and every DSD staff member, our most precious asset. Therefore, we have continued to proactively provide them with training to enhance their knowledge, skills and standard of professional services. We are also mindful of the occupational safety and health of our staff and working partners, and have organized site visits and experience-sharing sessions from time to time to facilitate cultivation of a safe working environment.” What form does staff training take?
“We arrange induction courses for new recruits so that they have a thorough understanding of our works and work with us to fulfil the Department’s service pledges. In 2015-16, we held four induction courses for a total of 163 newcomers.”
Occupational Safety and Health Training
“In 2015-16, we offered orientation briefings for 63 participants, with several sessions on topics covering the OHSAS 18001 Occupational Health and Safety Management System. We also held 10 types of Occupational Safety and Health (OSH) training for over 270 colleagues.
(For the topics of training and further info, kindly see Sustainability Report – Chapter 9)
“In addition to local training courses, we offer opportunities to make overseas duty visits to our staff for exchanging their expertise with foreign counterparts, learning from success stories, introducing state-of-the-art technology back in Hong Kong, and enhancing DSD’s service quality.”
Has the company made any significant investments in the past 12 months? Or does the company have any significant investments planned for 2017?
“Happy Valley Underground Stormwater Storage Scheme (HVUSSS).
“To alleviate the flood risks in Happy Valley and Wan Chai districts, we initiated the Happy Valley Underground Stormwater Storage Scheme (HVUSSS) in 2012, constructing an underground storage tank with a total capacity of 60,000 cubic metres, a box culvert of about 650 metres, and a stormwater pumping room rated at a peak flow of 1.5 cubic metres per second. It is the first flood prevention project in Hong Kong with a movable crest weir system and a Supervisory Control and Data Acquisition (SCADA) system.
“Phase 1 of HVUSSS was commissioned in March 2015. The three football pitches above the tank were reinstated and are now open to the public. The project team aims to complete the underground storage tank in Phase 2 before the 2017 wet season. Once the project is commissioned, the flood protection level of the region will be able to withstand rainstorms of a 50-year return period. The estimated cost for the entire project is about $1 billion.”
What are your flagship projects?
“The Harbour Area Treatment Scheme (HATS). During the year, the largest environmental infrastructure project in Hong Kong, The Harbour Area Treatment Scheme (HATS) – Stage 2A was commissioned, which would improve the water quality of Victoria Harbour to provide better living environment and quality for the public.
“It is the largest environmental infrastructure project in Hong Kong, with an aim to improve the water quality of Victoria Harbour by collecting and treating sewage generated from both shores. The project has was implemented in two stages, with construction works spanning over two decades at a total cost of $25.8 billion. With facilities for HATS Stage 2A came into full operation on 19 December 2015, all sewage from both sides of Victoria Harbour are now conveyed to a sewage treatment plant for treatment, disinfection and discharge into the western approaches of the harbour. This milestone for HATS marks the overall enhancement of water quality across the harbour.
“Physical constraints were overcome by cutting-edge engineering techniques adopted in this project, enabling the construction of deep sewage tunnels totalling over 44 kilometres in length at depths up to 160 metres below sea level. HATS also involved upgrading the sewage treatment capacity of Stonecutters Island Sewage Treatment Works (SCISTW) to 900 million cubic metres per year, enabling it to serve more than five million citizens.
“This project was conceptualized in 1989 with the Formulation of a Strategic Sewage Disposal Scheme (SSDS), with the first stage of construction commencing in 1994.
“This project is Hong Kong’s largest ever environmental infrastructure project and includes the world’s deepest sewage tunnel and the world’s largest CEPT plant.”
What new projects are underway?
“The upgrade of San Wai Sewage Treatment Works. The existing San Wai Sewage Treatment Works (SWSTW), serving part of the Yuen Long, Tin Shui Wai and Hung Shui Kiu areas in the Northwest New Territories (NWNT), is a preliminary treatment plant with design treatment capacity of 164,000 cubic metres per day. Since the existing SWSTW design treatment capacity will not be sufficient to meet the projected flow due to population growth in the NWNT from 2020 onwards, the daily treatment capacity of the SWSTW needs to be increased by 36 000 cubic metres to 200 000 cubic meters.
“The project “Yuen Long and Kam Tin Sewerage Treatment Upgrade – Upgrading of San Wai Sewage Treatment Works” involves construction of new preliminary treatment works, chemically enhanced primary treatment tanks, ultraviolet disinfection facilities, sludge dewatering facilities, a chemical storage house, a reuse water pumping station, deodorisation facilities, a new administration building with a workshop, new transformer houses and switch rooms, and ancillary facilities for the upgraded SWSTW. After the commissioning of the upgraded SWSTW, the existing SWSTW will be decommissioned.
“The project of upgrading the SWSTW costs $3,142,200,000. The consultant is AECOM Asia Co. Ltd. It is responsible for the design and site supervision of the SWSTW. The main Design, Build and Operate Contract was awarded in May 2016. The main contractor is ATAL – Degremont – China Harbour Joint Venture.
“The design and construction of the project started in mid-2016. The project is scheduled for completion by end 2020, followed by a 15-year contractual operation period.”