LCQ22: Improving quality and odour of coastal waters of Victoria Harbour
31.5.2023

Following is a question by the Hon Priscilla Leung and a written reply by the Secretary for Environment and Ecology, Mr Tse Chin-wan, in the Legislative Council today (May 31): Question: Regarding the efforts to improve the quality and odour of coastal waters of the Victoria Harbour (the Harbour), will the Government inform this Council: (1) of the annual Water Quality Objectives compliance rate of the Harbour Water Control Zone (WCZ) in the past year; (2) of the number of cases of misconnections of foul water pipes leading to the discharge of sewage to the Harbour WCZ which the Government followed up in the past year and, among such cases, the number of those which have been rectified, with a breakdown by District Council district; (3) among the cases mentioned in (2), of the respective numbers of those in which (i) rectifications were made after the owners had been given warnings/advice, (ii) rectifications were made after the owners had received statutory repair/removal orders or had been prosecuted, (iii) rectifications were still not yet made after the Government had taken law enforcement actions, and (iv) rectification works were carried out by government contractors; (4) of the following information on the Harbour WCZ sewerage improvement projects which (i) were completed in the past year, (ii) are now under construction and (iii) are pending funding approval by this Council: project name, year of completion/expected year of completion, as well as cost/estimated cost; and (5) of the latest implementation progress of the various proposals set out in the consultancy report on Further Enhancing Quality of Coastal Waters of Victoria Harbour? Reply: President, The Government has all along been attaching great importance to improving the water quality of Victoria Harbour and has devoted significant resources to improve the sewage collection and treatment systems through implementing the Harbour Area Treatment Scheme and works for enhancing the quality of coastal waters of Victoria Harbour, stepping up enforcement on misconnections of sewage pipes, and clearing sediment from the stormwater drainage systems. These efforts have brought noticeable improvement in the water quality of Victoria Harbour. The reply to various parts of the question is as follows: (1) The water quality of the Victoria Harbour Water Control Zone (WCZ) has been good. The overall compliance rate of Water Quality Objectives (WQOs) in the past five years has remained 90 per cent or above. The overall compliance rate in 2022 was 93 per cent, which was comparable to the five-year average of 95 per cent. The compliance rate of individual years would vary due to the influence on marine water quality by weather conditions, such as sunshine, temperature and rainfall, as well as the seasonal fluctuations of background levels. The slight decrease in the overall WQOs compliance rate of Victoria Harbour in 2022 was mainly attributed to the relatively high background levels of total inorganic nitrogen in seawater associated with the impact of the Pearl River flow and the southwesterly monsoon in summer months. Nonetheless, the marine water quality of Hong Kong has still shown a noticeable improvement overall. (2) In 2022, the statistics of the Government's follow-up actions on foul sewer misconnection in various districts are tabulated below: District Number of foul sewer misconnection cases Number of cases rectified Central and Western 14 0 Eastern 7 5 Wan Chai 30 6 Kowloon City 40 11 Kwun Tong 7 4 Sham Shui Po 9 4 Wong Tai Sin 2 1 Yau Tsim Mong 39 12 Kwai Tsing 3 3 Tsuen Wan 61 18 Total 212 64 (3) Among the cases mentioned in (2) above, 23 cases were rectified by owners after issuance of warnings or advice, 15 cases were rectified by owners after the statutory repair or removal orders were served, 73 cases have not been rectified after statutory repair or removal orders were served, 75 cases were under investigation or still under rectification, while 26 cases related to the maintenance of ageing public sewers and other problems were rectified by government contractors. We will continue to follow up on the remaining cases, urge or order the respective owners to fulfil their responsibility to rectify the pipe misconnection problems. For cases of non-compliance with the orders, the Buildings Department will take appropriate enforcement actions according to the circumstances, including consideration to initiate prosecution under the Buildings Ordinance (Cap.132). (4) The Government has all along been planning and implementing pollution control and sewerage projects in the Victoria Harbour WCZ. Relevant works projects completed in the past year and under construction are listed below: Projects completed in the past year (Note 1) Project Cost (Note 2) 1 Upgrading of West Kowloon and Tsuen Wan Sewerage - Phase 1 $280 million 2 Construction of Dry Weather Flow Interceptor at Cherry Street Box Culvert $660 million 3 Upgrading of Kwun Tong Preliminary Treatment Works $350 million 4 Enhancement Works for Kwun Tong Sewage Pumping Station $1,050 million Projects under construction Expected Completion Year Project Cost (Note 3) 1 West Kowloon and Tsuen Wan Village Sewerage - Phase 1 2023 $100 million 2 Revitalisation of Tsui Ping River (Associated Works for Dry Weather Flow Interceptor) 2024 $50 million 3 Upgrading of Central and East Kowloon Sewerage - Phase 3 2024 $680 million 4 Sewerage to Lo Wai, Chuen Lung and Kau Wa Keng Old Village 2025 $170 million 5 Upgrading of West Kowloon and Tsuen Wan Sewerage - Phase 2 2026 $2,290 million Regarding works projects that are pending for funding approval by the Legislative Council (LegCo), the Government will submit a funding application to the LegCo this year for the Construction and Rehabilitation of Trunk Sewage Rising Mains in Cheung Sha Wan to enhance the existing sewerage system. The project is expected to be completed in 2030. Furthermore, the investigation and design works of the newly designed dry weather flow interceptors to be installed at coastal areas at Hung Hom, Causeway Bay Typhoon Shelter, Tsuen Wan Bay, Wan Chai East and Shau Kei Wan Typhoon Shelter are in full swing. Subject to support from local communities and completion of relevant procedures, and with funding approved by the LegCo in the coming two years, these projects are expected to be commissioned and completed in stages from mid-2027 to early 2029. We are also planning and investigating for the Enhancement Works for Preliminary Treatment Works at Harbour Side, which are expected to be completed in 2030, and the project estimates will be assessed upon completion of the preliminary design. (5) The Government has completed the consultancy study on Further Enhancing Quality of Coastal Waters of Victoria Harbour and has been progressively implementing a series of measures based on the recommendations to improve the near-shore environment of Victoria Harbour. In addition to the progress on rectification of sewer misconnections to stormwater drains and relevant pollution control projects mentioned in the replies to items (2) to (4) above, the Government is taking forward, as stated in 2022 Policy Address, large-scale investigation work which focuses on districts that are more seriously affected by coastal odour so as to trace the major pollution sources in stormwater drainage systems in full swing, and also carrying out inspection, maintenance and desilting of public sewers and stormwater drainage systems on a regular basis. Our target is to reduce the pollution loading by half at stormwater outfalls with serious pollution problems on both sides of Victoria Harbour, in particular in Tsuen Wan, Sham Shui Po and Kowloon City districts, by the end of 2024. The Government has also started in March 2021 regular and extensive application of Malodour Control Hydrogel, which was jointly developed by the Drainage Services Department and the Hong Kong University of Science and Technology, at stormwater outfalls along the shorelines of Victoria Harbour and nearby locations with odour problems to reduce odour in drains. The Government will continue to adopt a multi-pronged approach, and implement various pollutant discharge reduction works projects and odour mitigation measures persistently, in order to further expedite the improvement of near-shore environmental and odour problems at Victoria Harbour. Note 1: Sewerage to Lei Yue Mun Village was completed in March 2023. Note 2: The project costs stated are approved project estimates. Note 3: The project costs stated are approved project estimates.