LCQ18: Water resources management and drinking water safety
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Question:
Some environmentalists have pointed out that with the intensification of global warming and the growth in the world population, water resources have become increasingly scarce. They consider that although Hong Kong currently does not have the problem of scarcity of water resources, the Government should step up its management of the precious water resources, and it should attach importance to drinking water safety, which has a direct impact on public health. In this connection, will the Government inform this Council:
(1) given that in recent years, countries such as the United States, Germany, Switzerland and Singapore and more than 30 Mainland cities have adopted the "sponge city" concept (i.e. to collect rainwater for use by a city and improve the city's flood relief capacity through enhancing the water storage capacity and water recycling system of the city) in their urban planning, and that the Secretary for Development indicated in August this year that the Government was actively taking forward this concept, whether the Government has conducted in-depth studies in this regard; if so, of the details; whether it has adopted such a concept in its planning for development of new towns and redevelopment of old districts; if so, of the details; if not, the reasons for that;
(2) given that the government departments currently involved in water resources management include the Water Supplies Department (WSD), the Drainage Services Department (DSD), the Environmental Protection Department, the Buildings Department and the Housing Department, whether the Government will, by making reference to Singapore's practice, set up a dedicated department to take up the responsibility of water resources management; if so, of the details; if not, the reasons for that;
(3) given that reservoirs overflow occurred in 10 of the past 11 years, resulting in the discharge of drinking water into the sea, and that the WSD and the DSD are implementing an Inter-reservoirs Transfer Scheme to transfer the overflow from the Kowloon Group of Reservoirs to Lower Shing Mun Reservoir, of the latest progress of the Scheme and the commencement and completion dates of the works; whether it has formulated new measures to reduce occasions of drinking water being discharged into the sea; if so, of the details; if not, the reasons for that;
(4) given that an environmental group had found perfluorinated chemicals, which are hazardous to human health, in the samples of drinking water taken from five reservoirs, and that such substance is currently not one of the regular parameters for monitoring drinking water quality, whether the Government will make reference to the practice of advanced countries and include such chemicals as one of the regular monitoring parameters, and whether it will publish, on a regular basis, monitoring reports on hazardous chemicals in drinking water; if so, of the details; if not, the reasons for that;
(5) of the date on which the Government last conducted a review on the system for conducting tests on drinking water from reservoirs and other details;
(6) as the Director of Audit's Report (the Report) published last month pointed out that for 63 of the 71 river monitoring stations situated in water control subzones, the average levels of Escherichia coli recorded in 2015 had exceeded the relevant water quality objectives, whether the Government has specific measures in place to improve the water quality of rivers; if so, of the details; if not, the reasons for that;
(7) given that one of the causes of pollution to watercourses is the failure to properly manage septic-tank-and-soakaway (STS) systems in rural areas, and that the Report pointed out that the 78 existing private desludging operators had not been issued with the relevant licences, whether the Government has measures in place to strengthen its regulation of STS systems and such type of operators; if so, of the details, including whether it will amend the legislation to impose heavier penalties on unlicensed engagement in such business; if there is no such measure, the reasons for that;
(8) given that currently the Government has added fluoride to drinking water to reduce the risk of dental decay in the community, but some medical research reports have pointed out that the intake of an excess level of fluoride will do harm to children's brain development, whether the Government has studied if fluoridation of drinking water (i) does more good than harm; and (ii) has impacts on children's brain development; if so, of the details; whether the Government will consider using instead other chemicals which have lower health risks; if so, of the details; if not, the reasons for that; and
(9) of the per capita water consumption and the total water consumption in each of the past 10 years, as well as the relevant details; whether it has studied how Hong Kong's per capita annual water consumption compares with the figures of other advanced cities in the world; of the new measures in place to encourage the public to conserve water; whether it has set a target for water conservation; if so, of the details; if not, the reasons for that?
Reply:
President,
The Government promulgated the Total Water Management Strategy in 2008 to address the challenges brought by climate changes. The strategy advocates containing growth of water demand by promoting water conservation and effective water mains leakage management. The strategy also seeks to develop a new water supply framework by exploring new water resources that are not susceptible to climate changes featuring the primary water sources of rainfall, Dongjiang water and seawater for flushing, and ancillary water sources covering desalination, reclaimed water, grey water reuse and rainwater harvesting. In this connection, the Water Supplies Department (WSD) commenced a consultancy study at the end of 2014 to evaluate the effectiveness of the current measures and project the long-term supply and demand of water up to 2040, with a view to making appropriate adjustments and enhancements to the current measures and formulating new policies and plans for water resources management.
The Government attaches great importance to the quality of drinking water supplied by the WSD to the general public. Under the current water quality monitoring scheme of the WSD, over 160 000 water samples are collected each year from catchment areas, impounding reservoirs, water treatment works, service reservoirs, trunk mains and consumers’ taps for an array of physical, chemical, bacteriological, biological and radiological tests to ensure that the water quality complies with the health-based guideline values of the World Health Organization (WHO). The relevant water quality monitoring data are regularly uploaded to the WSD's website for information of the public.
The following is our reply, after consultation with the Food and Health Bureau and the Environmental Protection Department (EPD), to the nine parts of the question:
(1) The Government has adopted the "sponge city" concept of "following the nature with flexibility" in designing the drainage improvement works completed in recent years. For instance, the engineered wetland of the Yuen Long Bypass Floodway can perform natural purification for the water bodies in the wetland effectively. Ho Chung River in Sai Kung and Lam Tsuen River in Tai Po are also designed to simulate natural river courses and adopt natural river bed substrate to facilitate infiltration of river water. The Government has also incorporated elements that simulate the natural water cycle in its large-scale drainage improvement works and drainage planning for new development areas, such as green rooftops, porous road surfacing and rainwater harvesting systems. The objective is to facilitate the infiltration, natural purification and reuse of rainwater with a view to enhancing our city's resilience to flooding.
At present, the Government is actively seeking opportunities, including suitable new development areas, for re-using harvested rainwater for non-potable uses. Taking the Anderson Road Quarry Development project as an example, the Government plans to construct an artificial lake that will feature the functions of flood prevention, providing leisure space and rainwater harvesting. During most of the time, the lake can serve as a leisure area for public enjoyment; at times of heavy rainstorms, it can impound rainwater and help reduce flooding risk downstream; part of the lake water can also be used for irrigation and other non-potable uses locally after treatment, serving triple purposes.
(2) Diverse models for water resources management are adopted in different parts of the world. The governments need to determine the most efficient framework for water resources management in the light of their own situation. At present, our primary water sources (i.e. rainwater collected locally, Dongjiang water and seawater for toilet flushing) and related facilities are managed by the WSD while stormwater drainage systems and facilities for collection, treatment and discharge of sewage are under the purview of the Drainage Services Department. The EPD is primarily responsible for monitoring the water quality of Hong Kong's marine, beaches and rivers, and enforcement of the Water Pollution Control Ordinance to regulate discharge and protect the waters from pollution. The Government has no plan to make any changes in this respect for the time being.
(3) Rainfall in Hong Kong varies greatly between dry and rainy seasons. As such, reservoirs are needed as buffers to cope with the seasonal imbalance in the supply and demand of water resources. In designing water catchment areas and reservoir capacities, our primary consideration is whether the water collected in the catchments and stored in reservoirs can meet the demand of the supply zones in dry years. Construction of a reservoir requires huge investments in terms of land and capital. If we focus on years with exceptionally high rainfall and construct an over-sized reservoir, the storage capacity would be wasted most of the time. This is neither an ideal way to utilise our land nor a cost-effective approach. Therefore, our reservoirs are generally of moderate size and may overflow during occasional persistently heavy rainfall.
In this connection, we are proactively taking effective measures to reduce overflow from reservoirs. Before the onset of the rainy season each year, we will make reference to the information provided by the Hong Kong Observatory to reduce total storage of reservoirs to allow more storage space for rainwater and, hence, reduce the chance of overflow.
The quantities of reservoir overflow have been reduced to 40.2 million cubic metres, 23.1 million cubic metres and 3.3 million cubic metres in 2013, 2014 and 2015 respectively. We will continue to study ways to further reduce reservoir overflow and convert the overflow into usable water resources.
When the Lai Chi Kok Transfer Scheme was formulated for reducing the flood risks in the West Kowloon region, the Government took advantage of the opportunity it presented to take forward the Inter-Reservoirs Transfer Scheme (IRTS) concurrently. Under the IRTS, a tunnel connecting the Kowloon Byewash Reservoir and the Lower Shing Mun Reservoir will be built to transfer the overflow from the Kowloon Group of Reservoirs to Lower Shing Mun Reservoir to achieve the dual objectives of reducing the run-off flowing into the Lai Chi Kok drainage system and converting the overflow into potable water resources. Currently, the Government is reviewing the detailed design, method statements and related environmental impact assessments of the IRTS in order to enhance its cost-effectiveness and prepare the implementation schedule.
(4) The 2011 edition of the WHO's Guidelines for Drinking-water Quality has not established any guideline values for perfluorinated chemicals (PFCs). Notwithstanding this, the WSD has been monitoring the levels of PFCs in raw water and drinking water under the Stockholm Convention's Persistent Organic Pollutants Monitoring Program. In this connection, the WSD has started to test for perfluorooctane sulfonic acid (PFOS) since July 2012. The sample test results also include data related to perfluorooctanoic acid (PFOA). The past monitoring results indicated that the levels of PFOA and PFOS in the reservoir waters were under the reporting values of 0.01µg per litre and 0.005µg per litre respectively, which were below the health advisory levels of the United States Environmental Protection Agency (Note 1) and the guidance levels of the United Kingdom's Drinking Water Inspectorate (Note 2). Therefore, the risk of reservoir water being polluted by PFCs is very low. The WSD has no plan to incorporate the PFCs into its routine monitoring programme. As for the other chemical compounds identified to be harmful to human health in the 2011 edition of the WHO's Guidelines for Drinking-water Quality, the WSD has kept them under regular monitoring and published the findings on its website.
(5) The WSD conducts annual review to formulate water quality monitoring programmes (including testing parameters for water quality and frequency) for reservoirs for the following year. The last review, concluded in February, covered sampling locations as well as testing parameters and frequency. Its findings confirmed that there was no need to revise the water quality monitoring programmes.
(6) The EPD has implemented the Water Pollution Control Ordinance and the Livestock Waste Control Scheme since the 1980s and formulated 16 Sewerage Master Plans for the whole territory. The above-mentioned legislation and various plans have brought about steady improvements to the water environment of Hong Kong. All gazetted beaches in Hong Kong have achieved the bacteriological water quality objectives since 2010. The Cross Harbour Race has also resumed since 2011. Moreover, 82 per cent of our rivers attained the grading of "Good" or above in 2015, as compared with only 35 per cent in 1986. The levels of Escherichia coli of our rivers have also been reduced by 80 per cent, when compared with those in the 1980s.The pollution load of most major rivers has also dropped significantly and up to a maximum of 96 per cent. The EPD will continue to pursue a multi-pronged approach to improve the river water quality in the most cost-effective manner. It will step up efforts to vet the design and performance of septic-tank-and-soakaway (STS) systems for new village house at the planning stage and take enforcement actions against the polluting STS systems. Village sewerage programmes will be implemented in the light of available resources and the local situation. Provision of dry weather flow interceptors at high risk or polluting areas and public toilets at unsewered rural areas will also be considered. The surface drainage systems will also be cleansed.
(7) The STS system is a cost-effective installation commonly used at village houses in Hong Kong and other countries. With proper design, operation and maintenance, the STS system can effectively curb pollution. To help residents of village houses operate their STS systems properly, the EPD has issued the Guidance Notes on Discharge from Village Houses, setting out guidelines on the operation and maintenance of the STS systems. Upon receipt of a pollution complaint, the EPD will inspect the STS system concerned and require the owner to make improvements. If the problem persists with evidence indicating pollution of nearby water bodies, the EPD will consider taking legal actions.
The EPD has introduced licensing regimes for the collection of chemical wastes and clinical wastes, with due regard for the different nature. But private desludging service providers are not required to obtain such collection licenses as the sludge in septic tanks are not hazardous wastes. As such, these service providers will not be held liable for operating without licence under the Waste Disposal Ordinance. Notwithstanding this, desludging service providers should stand vigilant and provide proper services to avoid adversely affecting environmental hygiene. The operators involved in illegal dumping of sludge from septic tank will be prosecuted. Under the Waste Disposal Ordinance, a person is liable to a maximum fine of $200,000 and imprisonment for six months on the first occasion on which he is convicted of unlawful disposal of waste. With regard to the Audit's recommendation for strengthening the regulation of desludging services, the EPD and the Food and Environmental Hygiene Department will review in detail the relevant provisions of the Waste Disposal Ordinance and, where necessary, consult the trade on the way forward.
(8) According to the Department of Health (DH), it is the consensus of international health authorities (including the WHO, World Dental Federation and American Dental Association) that water fluoridation is a safe and effective public health policy. Maintaining a suitable and low level of fluoride in the oral cavity can lower the risk of dental decay in both children and adults. According to the WHO's Guidelines for Drinking-water Quality, the guideline value for fluoride in drinking water is 1.5 mg per litre. The current level of fluoride in drinking water recommended by the DH in the light of the local situation is 0.5 mg per litre, which is far below the WHO's guideline value.
According to the DH's public health surveillance, water fluoridation plays an important role in maintaining the good oral health status of the Hong Kong population. The WSD has also closely monitored the fluoride content in the treated drinking water to ensure that the average fluoride content in drinking water complies with the DH's recommended level and is fit for consumption. The DH and WSD will continue to review the arrangement regularly.
As for the medical research of the effect of fluoride on neurodevelopment of children, the medical profession is still divided over the methodology, data analysis, etc. For instance, the fluoride concentrations in water adopted in the studies were significantly higher than the WHO's guideline value. The features of sampling locations of these studies were also different from the sources of drinking water. Therefore, the DH considers that there is no sufficient evidence to prove that adding appropriate amount of fluoride in drinking water will undermine people's health, including children's neurodevelopment.
(9) The annual total water consumption and per capita water consumption in Hong Kong in the past 10 years are shown in Annex 1.
Annex 2 sets out the the domestic per capita water consumption in some developed cities in 2014 as shown in the International Statistics for Water Services 2016 released by the International Water Association in the same year.
Over the past 10 years, the domestic per capita water consumption of Hong Kong fluctuated between 177 to 184 litres per day and, when compared with other major cities, falls within the middle strata. Since sea water is widely used for flushing purpose in Hong Kong, our actual per capita fresh water consumption is around 130 litres per day.
The WSD has adopted a multi-pronged approach to encourage the public to save water. It has rolled out an array of software and hardware measures to promote water conservation and set the target of saving 10 litres of water a day per person by reference to overseas experience in 2014.
On the software measures, the WSD has put emphasis on encouraging our young generation to develop water saving habits. It launched the "Cherish Water Campus" Integrated Education Programme for primary schools in the 2015/16 school year. As at November 2016, around 210 schools have joined the programme. The water conservation education will be further extended to kindergartens in the school year of 2017/18. Furthermore, a large scale five-day educational campaign, the Water Conservation Week 2016, was held from November 17 to 21 to help the public understand the challenges in relation to water resources that are brought by climate changes and encourage them to use less water. Over 20 000 people participated in the Water Conservation Week.
As regards the hardware measures, the WSD has given out flow controllers to nearly 140 000 households for participating in the "Let's Save 10L Water" Campaign. It has also completed the installation of flow controllers on water taps and showers at about 80 000 public housing households. It also plans to further promote the use of water saving devices by mandating the use of devices with the Water Efficiency Label in new developments and building renovation projects.
Furthermore, the WSD is constructing a new Water Resources Education Centre in Tin Shui Wai scheduled to commence operation in 2019 to enhance the knowledge of the public about water resources and water conservation.
Note 1: The United States Environmental Protection Agency has established health advisory levels for the total concentrations of PFOA and PFOS, which are perfluorinated chemicals found to cause significant human health effects, at 0.07µg per litre (70 nanogram per litre) respectively.
Note 2: The Drinking Water Inspectorate of United Kingdom has established 0.3µg per litre (300 nanogram per litre) as the guidance values for both PFOA and PFOS in drinking water.
Ends/Wednesday, December 14, 2016
Issued at HKT 18:05
Issued at HKT 18:05
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