In response to the fifth wave of COVID-19 epidemic, the Development Bureau (DEVB) set up a task force for co-ordinating with the Mainland’s construction support teams to provide community isolation and treatment facilities in full swing. Among them is San Tin community isolation facility, for which the Drainage Services Department (DSD) and the contractors have constructed a new public sewerage system and successfully commissioned it within just seven days. This time, I have invited frontline DSD colleagues to talk about the details and challenges of this emergency anti-epidemic project, as well as share with us their feelings.

The public sewerage works for San Tin community isolation facility included building a sewage pumping station and laying 1.8km of twin rising mains (i.e. a total of 3.6km of sewers) to convey sewage from the isolation facility to the sewage treatment facility at Lok Ma Chau Control Point. The construction of the sewerage system was fraught with challenges, including the substantial manpower required, the collection of materials, the search for a suitable location of the pumping station, the short lead time to complete the pumping station design, and so on.

About 200 people working around the clock

The works had to be carried out on a tight schedule. Engineer of the DSD’s Project Management Division, Mr NG Ting-hong, Mic, remarks that works of a similar scale normally take months to complete, but the DSD commissioned three contractors with a total of about 200 people to work around the clock at San Tin community isolation facility, which allowed the sewerage system to be completed in merely seven days.

Save time by changing the original alignment

Planning the alignment of the rising mains was a major challenge. Mr Mic NG says that the original alignment of the rising mains, which are 3.6km long and 200mm in diameter, was to run across the trunk road, San Sham Road, involving processes such as road closure, excavation, pipe laying, backfilling and road resurfacing, which would have taken at least two weeks. Fortunately, the project team worked together and eventually came up with an alternative alignment to avoid disrupting road traffic, saving a great deal of project time.

Besides, during the epidemic, materials are in very short supply. The 3.6km of rising mains is equivalent to the length of nine sports tracks. In addition to sourcing from five different suppliers, materials had to be raised from the DSD's sewage treatment facilities and the Water Supplies Department.

Quality of construction is essential

Despite the tight schedule, quality of construction remained a major concern. On the night of the completion of the sewerage system, colleagues from various sections under the DSD worked together in testing the pumping station and the rising mains, ensuring that there was no seepage in the entire system. Mr Mic NG says that the pumping station started operation at nearly midnight. A few minutes later, they received a call from the colleagues at the sewage treatment facility at Lok Ma Chau Control Point, confirming that the sewage from San Tin community isolation facility had successfully reached them, to the relief of Mr Mic NG and his DSD colleagues at the scene.

Improving the design and work processes continuously

Regarding the location of the pumping station, Engineer of the Electrical and Mechanical Projects Division, Mr LAW Tsz-wai, David, says that the department had to consider quite a number of factors, such as the sewage system layout of the isolation facility, surrounding usable government land and daily maintenance of the pumping station. Also, the department had to complete the pumping station design in a short time and purchase mechanical and electrical equipment and building materials immediately. At the same time, the team improved the design and work processes continuously so that the works could be completed as quickly as possible.

For example, wet wells of sewage pumping stations are traditionally built underground in general. However, considering that such deep excavations would take a long time, it was suggested to have the wet well built on the ground. To accelerate the process, some colleagues discussed the above possibility with contractors at the site, while others altered the layout. They were indeed racing against time.

Workers volunteered to shorten rest time and meal breaks

Engineer of the Mainland North Division of the DSD, Ms FENG Xue, Stephanie, shares with us that in respect of works, apart from civil structural works such as traditional formwork erection, fixing of reinforcement and concreting, the team also had to liaise with mechanical and electrical works contractors for the installation of pipes, pumps and other mechanical and electrical equipment required. Frontline workers worked around the clock for days and immediately returned to work after going home at night to rest for a few hours. One night, in order to complete the final concrete pour before midnight, workers volunteered to shorten their meal breaks and rest time, sparing no effort to finish their job.

The project could not have been completed smoothly if not for the concerted efforts of the project team. The Director of Drainage Services, Ms Alice PANG, visited the construction site many times to encourage and thank colleagues for their active participation in anti-epidemic work. Mr David LAW shares with us that he is delighted that he can contribute to Hong Kong’s anti-epidemic work with his professional knowledge. Mr Mic NG says that he is proud to be a member of the DSD and do his part to fight the epidemic for Hong Kong. Ms Stephanie FENG remembers the tremendous support given by her family during the construction. Although she left home early and returned home late, her child always said, “Keep it up, mum, stay safe!”, every morning before she left home, giving her a lot of encouragement.

With the community isolation facilities completed one by one, we are able to isolate more confirmed patients in appropriate facilities. I would like to thank colleagues of the works departments for their demonstration of team spirit throughout the course of this urgent project. As our colleague says, the fight of one person against the epidemic is small, but if we work together and stay united, we will become a powerful force that can win the fight.