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LCQ19: Air quality monitoring network

     Following is a question by the Hon Kenneth Chan and a written reply by the Secretary for the Environment, Mr Wong Kam-sing, in the Legislative Council today (July 17):


     It was mentioned in "A Clean Air Plan for Hong Kong" published by the Environment Bureau in March this year that new general air quality monitoring stations (general AQMS) would be installed in Tuen Mun in 2013 and in Tseung Kwan O between 2014 and 2015.  Regarding the air quality monitoring system in Hong Kong, will the Government inform this Council:

(a) whether the authorities have drawn up a specific work plan and timetable for installing a general AQMS in Tseung Kwan O; if they have, of the relevant details and the latest progress of implementation; if not, when the authorities will draw up and announce the relevant plan and timetable; if the authorities have not yet decided on the formulation of such a plan and timetable, of the reasons for that; when the general AQMS under construction in Tuen Mun will come into operation;

(b) as the authorities indicated in reply to the questions asked by the Members of this Council on January 6, 2010 and July 4, 2012 respectively that "we consider it unnecessary to set up an AQMS in each of the 18 districts at present" and "the current monitoring network can adequately reflect the level of air quality in Hong Kong...  At present, we have no plan to increase the number of AQMSs", and the Director of Audit pointed out in his report published in October 2012 that as there was rapid development and population growth in Tseung Kwan O, a general AQMS was proposed to be installed in the district, and the Environmental Protection Department has supported the proposal and commenced a preliminary site search for the purpose, of the reasons and justifications for the authorities to change their policy;

(c) as I have learnt that the authorities had proposed the setting up of a general AQMS in Tseung Kwan O as one of the compensational measures when they tried to persuade the residents of the district to agree to the proposal for extending the Southeast New Territories (SENT) Landfill (the extension project), and the authorities have withdrawn the funding application for the extension project, whether the authorities will adjust or even withdraw the plan to set up the general AQMS; if they will, of the details; if a decision on whether to set up a general AQMS is made independent of the extension project, whether the authorities have assessed if regarding this proposal as a compensational measure in the course of persuading the residents is misleading;

(d) whether the authorities will conduct a comprehensive review of the number and spatial distribution of monitoring stations to ascertain the need to set up general and roadside AQMSs in more areas; if they will, of the details of the review; if not, the reasons for that;

(e) whether, in planning for the number, type, distribution and specific location of AQMSs, the authorities have made decisions on the basis of an objective and quantifiable set of standards; if they do, of the details of such standards; if not, the conditions and criteria based on which the authorities make decisions; and

(f) whether the authorities will consider conducting policy research and public consultation on improving the air quality monitoring system in order to gather public opinions on the matter, especially those of the residents in the districts concerned and green groups; if they will, of the details; if not, the reasons for that?



(a), (b), (d) and (e) In setting up the air quality monitoring network, the primary objectives of the Environmental Protection Department (EPD) are to collect data for assessing the impact of air pollution on the public, facilitate the formulation of an air quality management strategy and evaluate its effectiveness.  We adopt the internationally recognised guidelines (such as the guidelines of the United States Environmental Protection Agency) for the design of the monitoring network and site selection of the monitoring stations.  We also implement a stringent quality control and assurance system to ensure that the data on air quality are accurate, reliable and representative.

     To collect representative air quality data, we will take into account various factors in determining the locations of the air quality monitoring stations (AQMSs), namely, spatial distribution of AQMSs in the network, coverage of different types of development areas (such as urban areas, new towns and rural areas), distribution of local population, traffic flow and distribution of sources of pollution, topography and meteorology, representativeness in terms of the local air quality, and the capability of monitoring regional air pollution.

     The EPD also conducts annual reviews on the monitoring network in the light of the above factors to consider if the network should be refined, which may include adding new monitoring stations or monitoring parameters.

     Hong Kong is a small and densely populated city and its economic activities are mainly commercial and financial.  As such, vehicle emission is a key local source of air pollution and the levels of air pollution in different districts are mainly determined by their respective types and density of development.  The levels of air pollution in districts with similar types and density of development are more or less the same.  The current air quality monitoring network, comprising 11 general AQMSs, covers the major areas of Hong Kong from east to west and from south to north with a distribution covering different land uses (residential, commercial, industrial and a mix of them) of the urban areas, new towns and rural areas.  Therefore, the current air quality monitoring network can reflect the overall air pollution situation in districts with different types of development in Hong Kong, serve as a reliable basis for drawing up an air quality management strategy, and provide the public with representative data on air quality.

     In addition, the EPD has set up three roadside AQMSs at busy traffic corridors in built-up urban areas with a large number of pedestrians so as to monitor roadside air quality.  These three roadside stations are in Causeway Bay, Central and Mongkok, covering the more densely built-up and most common types of land use in urban areas, including commercial, commercial-cum-residential and financial areas, etc.  The data collected by these roadside AQMSs can reflect the roadside air quality along busy traffic corridors with a heavy pedestrian flow in the urban areas in Hong Kong.

     Given the rapid development of Tseung Kwan O and the further growth in its population in future, as well as its unique topography, after the annual review on the air quality monitoring network in November 2012, the EPD planned to set up a general AQMS there.  The EPD has started a site selection survey on the AQMS in Tseung Kwan O, and aims to consult Sai Kung District Council on the preliminary siting proposal around September this year.  After the location is confirmed, the EPD will start the design and construction of the AQMS as soon as possible.  

     The new AQMS in Tuen Mun is now undergoing a baseline monitoring for 12 months, and its quality control and data systems are being refined to align with the standards of the general air quality monitoring network.  We expect that real time air quality monitoring data can be reported from this station starting from the end of this year.

(c) The Government's plan to establish an AQMS in Tseung Kwan O is a positive response to the concerns on air quality of the local residents.  The setting up of the AQMS would not be affected by the SENT Landfill Extension project.

(f) The EPD will continue to conduct annual reviews on the air quality monitoring network according to the established mechanism and by making reference to the relevant factors such as spatial distribution of AQMSs in the network, coverage of different types of development, distribution of local population, traffic flow and distribution of sources of pollution, etc.  In addition, the EPD is making preparations for a territory-wide short-term and intensive air quality monitoring study covering general and roadside air quality in the coming one to two years.  The findings of the study can provide useful data for the review of the monitoring network.  The EPD will also invite local air scientists to advise on the study and further enhance our air quality monitoring system.

Ends/Wednesday, July 17, 2013
Issued at HKT 15:04


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