LCQ4: Perfluorinated chemicals in drinking water and quality of Dongjiang water

Following is a question by the Dr Hon Helena Wong and a reply by the Secretary for Development, Mr Paul Chan, in the Legislative Council today (January 6):


It has been reported that an environmental group recently took 10 water samples from five reservoirs storing drinking water for laboratory tests, with test results showing that all samples contained perfluorinated chemicals (PFCs), which are hazardous to human health. It has also been reported that the water quality monitoring data of Dongjiang (DJ) water samples taken from the Muk Wu Pumping Station in Hong Kong by the Water Supplies Department (WSD) last year indicated that the level of faecal coliforms in the water samples exceeded the standard by six times during the summer and that the total phosphorus level was the highest in the past decade, which had been caused by the discharge of flood water from Shawan River in Shenzhen, which is downstream of DJ, during heavy downpours. Regarding the monitoring of PFCs in drinking water and the environment as well as the quality of DJ water, will the Government inform this Council:

(1) in respect of the levels of PFCs, how the water samples taken in each of the past five years by WSD from reservoirs storing DJ water compare with those taken in the same period from reservoirs storing only rainwater; if the levels of PFCs in the former samples are higher, whether it has looked into the reasons for that; of the details of such water samples' monitoring data (including the dates and locations for taking such samples, as well as the data of various monitoring parameters);

(2) why WSD has not published the monitoring data of PFCs; whether it has any plan to include this substance as one of the regular parameters for monitoring the quality of drinking water and to set the relevant standard values; if it does, of the details; if not, the reasons for that; given that PFCs are widely used in the production of various goods (including waterproof clothes and gears), whether the authorities will introduce legislation to ban or restrict the import or sale of goods such as clothes which contain PFCs, so as to prevent such chemicals from being released into the environment; and

(3) given that the Government indicated in its reply to a question raised by a Member of this Council in February 2009 that the Guangdong and Hong Kong sides had, after discussions, implemented four measures and works to mitigate water pollution, namely (i) enforcing more strictly the environmental legislation, regulating the pollution emitters along DJ, as well as strengthening the supervision and monitoring of wastewater discharge points along rivers, (ii) stepping up control over land use planning and environmentally unfriendly activities, (iii) improving progressively the water resource management and real-time monitoring system, and (iv) implementing wastewater interception schemes at Shenzhen Reservoir to ensure no contamination in the reservoir, of the details of the authorities' implementation of these four measures and works as well as the latest progress, and whether they have other measures in place to further improve the quality of DJ water?



Under the Hong Kong Special Administrative Region Implementation Plan for the Stockholm Convention on Persistent Organic Pollutants (the Convention), the Water Supplies Department (WSD) has started conducting environmental baseline surveys for 12 persistent organic pollutants (POP) in raw water and drinking water and regularly submitted relevant progress reports to the Environmental Protection Department (EPD) since 2006. Subsequently, a total of 10 new POP items were added to the Convention in 2009 and 2011. In light of this development, the WSD has started to include these 10 items in its environmental baseline surveys since July 2012, including perfluorooctane sulfonic acid (PFOS) (a type of perfluorinated chemicals (PFCs)). The sample test results also include data related to perfluorooctanoic acid (PFOA) which is not covered by the Convention. The WSD's monitoring results indicate that the PFOA and PFOS in raw and treated drinking water are both under 0.01 mcg/L.

In regard to quality of drinking water, the WSD has formulated water quality objectives for its water supply on the basis of the 2011 edition of the Guidelines for Drinking-water Quality of the World Health Organization (WHO Guidelines). However, the WHO Guidelines do not set any guideline values for PFCs. We have made reference to the relevant health-based guideline values stipulated by the Environmental Protection Agency of the United States (EPA) and the Drinking Water Inspectorate (DWI) of the United Kingdom. As the present PFOA and PFOS levels in our raw and drinking water are far below the health-based guideline values stipulated by the above-mentioned regulatory institutions, they would not affect the health of the public. 

As for the water quality of Dongjiang (DJ) water, the DJ Water Supply Agreement signed between Hong Kong and Guangdong (GD) authorities has stipulated that the quality of the DJ water supplied to Hong Kong shall comply with the standards set out for Type II waters in the Environmental Quality Standards for Surface Water (GB3838-2002). The results of the WSD's regular water quality monitoring work showed that the DJ water supplied to Hong Kong was of consistently good quality and the average values of various monitoring parameters were in full compliance with the water quality requirements under the Agreement. But certain water quality indicators of DJ water might occasionally deviate from the stipulated values for Type II waters in the GB3838-2002 under exceptional circumstances. The GD and Hong Kong authorities will liaise closely and adopt appropriate measures to enhance the water quality of DJ water.

The following is the reply of the Development Bureau, after consultation with the Environment Bureau and the Commerce and Economic Development Bureau, to the Dr Hon Helena Wong's question:

(1) The WSD has started to test for PFOA and PFOS since July 2012. The test results in the past years are set out in the annex. The test findings indicated that while the PFOA and PFOS values in the DJ water were higher than the local water sources, they were still far below the provisional advisory values of the EPA (400 ng/L for PFOA and 200 ng/L for PFOS) and the guideline values of the DWI (300 ng/L for both PFOA and PFOS).

(2) The WSD has started conducting environmental baseline surveys for PFOS since 2012, but this is not part of the routine monitoring work on drinking water quality. Therefore, the WSD has not published any monitoring data on PFOS on its website. As for stipulating the guideline values for PFOS in drinking water, the WSD will watch out for the relevant development by the WHO and take appropriate follow-up actions accordingly.

As regards PFOS, the Convention only controls the manufacture, export, import and use of this chemical, but would not regulate the export, import or sale of products containing it. As a matter of fact, the number of states to the Convention is now 179. According to information of international research and regulatory institutions, the exposure of the public to PFCs due to contact with commodities remains at a low level, although many goods contain PFCs. The Government has no plan to prohibit or control the import and sale of articles containing PFCs for the time being.

(3) The latest progress on the four measures and works for mitigating water pollution is as follow:

(i) On regulating pollution emitters along the DJ River, the number of completed sewage treatment plants in the DJ River Basin has more than doubled from 72 plants at the end of 2009 to 147 by the end of June 2015. The daily treatment capacity has also increased over 60 per cent over the same period, from 5.695 million tonnes to 9.328 million tonnes.

(ii) On stepping up control over land use planning and environmentally unfriendly activities, the GD authorities amended the "Water Quality Protection Rules for Dongjiang System in Guangdong Province" in 2010 and implemented the "Measures for Protecting the Water Resources of the Reservoirs and Reservoir Zones of Xinfengjiang, Fengshuba and Baipenzhu at the Dongjiang River Basin in Guangdong Province" in 2011. These measures include prohibiting polluting activities within these reservoir protection zones, such as quarrying, mining and large scale livestock farming. In recent years, the GD authorities have closed down 472 illegal mines, 19 small steel factories and one cement plant; demolished the facilities of 255 illegal aquaculture operations; and banned the operations of over 130 house boats and 60 catering boats.

(iii) Regarding the progressive improvements to the water resource management and real-time monitoring system, the GD authorities commenced operation of the newly commissioned DJ Water Quantity and Quality Real-time Monitoring and Control System in 2015 to further enhance the protection of water resources in the DJ River Basin.

(iv) The Shawan River no longer flows into the Shenzhen Reservoir normally. It may only discharge floodwater into the Shenzhen Reservoir when its water level rises steeply to the alert threshold as a result of a heavy rainstorm during flood season. The WSD has raised its concerns about the flood discharge of the Shawan River to the GD authorities and received a positive response, including the introduction of a notification mechanism for flood discharge from the Shawan Interception Point that would enable the WSD to make prompt and appropriate arrangements. Furthermore, the Shenzhen authorities will also undertake a comprehensive remediation project for the water environment of the Shawan River Basin shortly to protect the water quality of the Shenzhen Reservoir. The whole project will take two to three years to complete.



Ends/Wednesday, January 6, 2016
Issued at HKT 17:36