Some of today's grandparents may still recall those blithe sunny days they raced across the Victoria Harbour in their groovy swimming gear. To the younger generation, that day may come again before they become grandparents themselves, all thanks to the hard work and dedication of an elite engineering team that has devoted much of the past 15 years to building an impressive harbour area treatment infrastructure.
"Results have been encouraging but we still have a long way to go," says Chui Wing-wah, chief engineer, harbour area treatment scheme division, Drainage Services Department.
The immediate benefits may escape the public eye but the initial stage of the harbour area treatment scheme (HATS) has been operating at full swing since its completion in 2001. The project includes, among its peripherals, the construction of a network of 23.6-kilometre long and 150 metre-deep sewage systems which stretch along the coast from Tsuen Wan down to Tseung Kwan O and across to Chai Wan and Shau Kei Wan.
The system can carry and provide treatment to a peak sewage flow of 39.8 cubic meters per second to the purpose-built Stonecutters Island Sewage Treatment Works (SCISTW), one of the largest and most efficient treatment plants of its kind in the world.
The screening and de-gritting capabilities and the operational reliability of eight of the existing preliminary treatment works (PTWs) have also been upgraded, giving around 75 per cent of the sewage flowing into the Victoria Harbour an enhanced chemical treatment.
In the pipeline
Hong Kong is densely populated and the number of people living on both sides of the harbour is expected to increase to more than five million in the years to come, adding extraordinary pressure to the existing sewage systems.
To contribute to the sustainability of harbour area development, a small but capable HATS team comprising four senior engineers and nine engineers is overseeing the many phases of the project, working closely with environmental scientists, infrastructure engineers, architects, contractors, treatment facility operators and many other parties involved.
"Aside from technical know-how and expertise in respective areas, building a good rapport is key to the success of the project," Mr Chui stresses.
Mr Chui himself has been part of the project since 1994. He notes that the job has been challenging in parts and very interesting on the whole.
"For instance, we build the sewage tunnels at great depths making sure there are at least 30 metres of rock above the tunnel system so as to minimise potential impacts on existing and future land development," Mr Chui explains. "The entire undertaking is not just about building the necessary hardware to meet contemporary society needs. We must put things into perspective while connecting people of all interests," he notes, adding that resolving disagreements and achieving consensus can be lengthy yet satisfying processes.
"There were many voices and expectations in the initial concepts, so a number of international experts from diverse backgrounds such as marine life, wastewater management, economics and infrastructural engineering were brought in to assess the grand plan," Mr Chui says. "The project has also attracted many delegates from other jurisdictions who came for technology exchange, bringing with them insights and ideas."
Upon completion of a series of environmental impact assessments and engineering feasibility studies, the government has decided to forge ahead with the implementation of the second stage of the project which will upgrade the remaining PTWs, extend the tunnel system to cover the northern and south-western parts of Hong Kong Island, and expand the existing chemical treatment and provide disinfection facilities at the SCISTW.
The bill was huge for a massive infrastructure like this but with sufficient public education, heightened environmental awareness and better communication, the project has received tremendous support and subsequently generous applause from the Hong Kong public.
"Public engagement is indispensable," Mr Chui emphasises. For this reason, rounds of consultation with environmental groups, academia, professional bodies and the general public have been held to garner opinions prior to every stage of the project. "It is also important that we explain our work to the public in layman terms," he says.
Meanwhile, meetings with district councils and committees as well as the Harbour-front Enhancement Committee are ongoing. "This helps us to fine-tune our research and make sure everybody is on the same page. We believe that a high level of interaction and transparency can facilitate smooth implementation of an environmentally sound and economically viable infrastructure to generate a wealth of long-term benefits for Hong Kong," Mr Chui says.
In celebration of 20 years of service excellence, the Drainage Services Department is organising a 20th Anniversary Open Day at the Stonecutters Island Sewage Treatment Works tomorrow (21 March 2009). The occasion will see a showcase of the nuts and bolts of the Harbour Area Treatment Scheme, including a state-of-the-art deep tunnel conveyance monitoring system and a plethora of HATS-related information.