LCQ19: Revitalisation of Tuen Mun River

     Following is a question by the Hon Michael Tien and a written reply by the Secretary for the Environment, Mr Wong Kam-sing, in the Legislative Council today (January 19):
 
Question:
 
     The Drainage Services Department (DSD) commenced the Review and Selection of River Sections for Revitalisation – Feasibility Study in early 2021 to select river sections with revitalisation potential and identify the preliminary scope of relevant revitalisation works. The study covers Tuen Mun River and is scheduled for completion in 2023. However, some residents of Tuen Mun district have relayed that the pollution problem of Tuen Mun River has been severe all along. They always see a lot of grease and rubbish, including styrofoam, food waste and construction materials floating on the surface of Tuen Mun River, and they smell stenches from time to time. The hygiene conditions are worrying. Although quite a number of residents have complained to the Environmental Protection Department, the Food and Environmental Hygiene Department and the DSD (the three departments) over the years, those departments have often shirked their responsibilities, and thus the conditions have not seen any improvement. In this connection, will the Government inform this Council:
 
(1) of the respective numbers of complaints or reports about the hygiene and stenches of Tuen Mun River received by the three departments in each of the past three years;
 
(2) whether the three departments explored in the past three years the main causes of the river water pollution of Tuen Mun River;
 
(3) of the details of the inspection and desilting work carried out at Tuen Mun River by the three departments in each of the past three years, including the number of inspections, as well as the manpower and expenses involved;
 
(4) as it has been reported that the pollution of Tuen Mun River may be caused by the misconnection of foul water pipes which discharge industrial wastewater to the river, whether the Government commenced investigations in the past three years into the sources of such industrial wastewater; if so, of the number of prosecutions instituted each year; and
 
(5) whether Tuen Mun River has been included in the revitalisation scheme; if so, of the latest progress of the revitalisation works?
 
Reply:
 
President,
 
     The Government has been striving to improve the water quality of Tuen Mun River with the continuous implementation of a number of measures, including phased planning of the public sewers for rural villages in upper stream of Tuen Mun River, directing domestic sewage from villages to public sewers gradually, tracing pollution sources, stepping up enforcement actions, rectifying sewer misconnections, clearing stormwater drains and conducting desilting works. The sewer connection works of Lam Tei, Fuk Hang Tsuen (Upper), Fu Tei Ha Tsuen, Kei Lun Wai, and part of both Tuen Tsz Wai and Tsing Chuen Wai have been completed. Separately, the sewerage works at Fuk Hang Tsuen (Lower), Tsz Tin Tsuen, Po Tong Ha and Siu Hang Tsuen are currently under construction and expected to be completed in 2024. In addition, the Environmental Protection Department (EPD) combats the pollution at source and installs dry weather flow interceptors to prevent discharge of pollutants into stormwater drainage system. In terms of overall river water quality, Water Quality Index gradings of the middle and lower sections of Tuen Mun River have been maintaining at "Good" for many years. Having consulted the Food and Environmental Hygiene Department (FEHD) and the Drainage Services Department (DSD), the consolidated reply to the question raised by the Hon Michael Tien is provided as follows:
 
(1) The respective numbers of complaints or reports about the hygiene and stenches of Tuen Mun River received by the EPD, FEHD and DSD in each of the past three years are provided as follows:
 

 
(2) As aforementioned, the Government has been planning public sewers for the rural villages upstream of Tuen Mun River to progressively direct their domestic sewage to the public sewers. As some villages are yet to be connected to public sewers and rely on private-built septic tanks for sewage treatment, the effectiveness of sewage treatment may be affected when some of these septic tanks are not properly maintained. In addition, the misconnection of building and restaurant sewers or public sewers to stormwater drains along the coastal areas as well as illegal discharge results in pollutants discharging into Tuen Mun River that affects the water quality of some river sections and causes odour problem.
 
(3) The government departments have been working closely to manage matters in relation to Tuen Mun River, including its water quality, hygiene and drainage capacity etc.
 
     The EPD continues to conduct proactive pollution source inspections in Tuen Mun district in order to combat pollution at source and intercept the illegal discharge of pollutants into the stormwater drainage system. In addition, upon receiving related pollution complaints, our staff will promptly conduct targeted site inspections, perform pollution source investigations in the upstream area and take appropriate enforcement action. Should there be any illegal discharges, enforcement actions will be taken. If we identify any misconnection of building foul sewer or public foul sewer to stormwater drains, the case will be immediately referred to the Buildings Department (BD) or DSD for follow-up. Since 2020, we have introduced the Geographic Information System (GIS) technology to systematically and accurately record case details, optimise inspection and follow-up procedure so as to improve case handling efficiency. The details of inspections on Tuen Mun River conducted by the EPD in each of the past three years are tabulated below:
 

*The above work is part of the EPD daily pollution control work. Therefore, there is no detailed breakdown on manpower resources and expenditure involved in individual items.
**Half of the cases have been rectified by the BD or DSD.
 
     The FEHD has been sending staff to inspect the hygiene condition of Tuen Mun River on a regular basis. The number of inspections conducted by the FEHD, the number of clearance of floating refuse on the river surface carried out by its contractors, and the expenditure involved in refuse clearance in each of the past three years are tabulated below:
 

*The FEHD does not maintain a breakdown of the manpower expenditure involved in inspections.
 
     The DSD and relevant public works departments carry out desilting work for the section of Tuen Mun River from Siu Hong Station on Tuen Ma Line to the estuary in a timely manner to ensure the proper functioning of Tuen Mun River and maintain its drainage capacity. On average, the DSD conducts inspections on Tuen Mun River for about two to three times a month, inspecting the river condition and arranging desilting and river embankment cleaning when necessary. In December 2021, the DSD started to test the use of remote-controlled desilting robots to carry out underwater desilting work on Tuen Mun River near Tuen Mun Station on Tuen Ma Line to enhance desilting and improve the condition of the river.
 
     The number of inspections on Tuen Mun River conducted by the DSD and relevant public works departments, the number of desilting and river embankment cleaning and the cost in each of the past three years are as follows:
 

 
(4) The industrial area near Tuen Mun River is mainly located in Tuen Mun Industrial Center and Nan Fung Industrial City, the westward of Tuen Mun River. The number of inspections conducted, sewer misconnection cases identified and prosecutions instituted under the Water Pollution Control Ordinance in the vicinity of the industrial area near Tuen Mun River in each of the past three years are tabulated as follows:
 

* Two cases have been rectified by the DSD
 
(5) The DSD is conducting a feasibility study for rivers revitalisation, and Middle Tuen Mun River Channel is evaluated as an area with revitalisation potential. The DSD is currently exploring practical means of improving the water quality to establish its feasibility. The study is targeted for completion in 2023. The preliminary design and planning stages will be proceeded after creating a project item for Revitalisation of Middle Tuen Mun River Channel.