Large-scale maintenance works for Stonecutters Island Sewage Treatment Works completed
The Environment Bureau announced today (March 21) that the Drainage Services Department (DSD) completed the large-scale maintenance works and replacement of electrical and mechanical facilities at the Stonecutters Island Sewage Treatment Works (SCISTW) on March 17.
The Secretary for the Environment, Mr Wong Kam-sing, said that the maintenance works had been a very challenging project. In order to minimise the potential impact of the project on the public, the DSD and the Environmental Protection Department had completed detailed assessment and preparatory work at the outset, and also formulated and implemented contingency plans as well as various mitigation measures with a number of departments.
The SCISTW has been in continuous operation 24 hours a day since it was put into service in December 2001. Notwithstanding timely maintenance of all facilities carried out by the DSD during the period, some of the major electrical and mechanical facilities were approaching the end of their service lives in 2018. Replacement works had to be carried out with the aim of maintaining the proper functioning of the whole system.
The DSD originally planned that bypasses of part of the preliminarily treated sewage from the upstream preliminary treatment works into Victoria Harbour would be carried out on up to five occasions, each not exceeding two weeks, within two years (from 2018 to 2020) with a view to facilitating the replacement and maintenance work. The third bypass was completed during the period from March 4 to 17 following the successful completion of the first and second bypasses last year. During every bypass, the DSD implemented a series of mitigation and contingency measures as well as comprehensive water quality monitoring, and uploaded relevant information to the Internet on a regular basis. As demonstrated by the relevant water quality monitoring results, the impact on the water quality of Victoria Harbour was slight and transient. The water quality returned to normal in a few days after cessation of the bypasses. The bypasses did not have significant impact on sensitive waters including beaches, fish culture zones or coral sites near Victoria Harbour.
The large-scale maintenance works and replacement of electrical and mechanical facilities were successfully completed during the third bypass because the progress of the works was not only satisfactory but beyond expectation. As a result, there was no need to carry out the fourth and fifth bypasses in the fourth quarter this year and the first quarter next year respectively as envisaged in the original plan.
The DSD will continue to carry out timely maintenance and monitoring of the SCISTW with a view to providing members of the public with top-quality and reliable sewage treatment service and safeguarding the water quality of Victoria Harbour.