Construction starts on Tuen Mun sewer

Chun Wo Development Holdings (a Hong Kong construction company founded in 1968) announced on 7 November that it has begun work on the HKD 710M (USD 91M) Western Trunk Sewerage Project in Tuen Mun, Hong Kong.

The project aims to increase the capacity of the sewer collection system by building a 6km long trunk sewer and a pumping station.

A remote-controlled TBM was the chosen method to bore the necessary 4km of pipejacked tunnel as it has the smallest impact on residents. It has not been foreseen that any road excavation will be necessary.

2.5km of the pipejacked sewer will be in DN1800 concrete gravity pipe, with 1.5km as a DN1400 sleeve pipe for twin hdpe rising mains of DN900. The remaining 2km of sewer will be laid as a twin-cell box culvert.

Clement Kwok, the managing director of Chun Wo, said, “we are pleased to become the main contractor of the Tuen Mun Western Trunk Sewerage Project. In order to mitigate the impact to the local residents, we have purchased two new TBMs for laying the underground pipes. We hope the technology can be more widely applied in Hong Kong in the future to preserve the quality of living environment for local residents while we push ahead with city development projects.”

The project runs alongside a series of similar endeavours. The HKD 20bn (USD 2.6bn) Harbour Area Treatment Scheme (HATS) of Victoria Harbour transfers waste through a deep tunnel system for treatment at a central plant on Stonecutters Island. Sewerage has been a priority for Hong Kong since 1989 and with the later release of the ‘16 Sewerage Master Plans’ by the Environment Protection Department.

The need for sewer expansion stems from Hong Kong’s rapidly growing population. Since World War II, the population has increased approximately 12 times, to seven million. Some 93 per cent of the inhabitants are served by the current sewer system, which has a total length of approximately 1600km.

The Tuen Mun project will be completed by 2014, providing increased capacity for future development.