First Stage Public Engagement Document for the Review And Development Of Marine Water Quality Objectives
1. Public Engagement
The Environmental Protection Department (EPD) has embarked on a review of our marine water quality objectives (WQOs) so as to enhance the protection of the water environment in an evolving scientific setting, and to promote the conservation and the best use of the waters of Hong Kong in the public interest. Our review examines the existing WQOs in light of the local conditions and overseas best practices; and subject to the findings, we may consider refining the existing WQOs and/or developing new WQOs. The review will also examine the technical attainability and potential socio-economic implications associated with any proposed changes to the WQOs.
We shall conduct the public engagement in two stages to seek views from the public on the issues to be addressed, and any proposed changes to the WQOs. This document is intended for informing the public of the local conditions and overseas trends, and seeking your views on the issues to be addressed and the review approaches. More importantly, we encourage the public to express views on the best ways to develop the WQOs so as to enhance the protection of our marine environment in the coming decades.
2. Our Yardstick: Water Quality Objectives (WQOs)
Our marine waters are a valuable natural asset. They support a huge variety of wildlife, from microscopic plankton, seagrasses and corals, to green turtles, horseshoe crabs, dolphins and finless porpoises. For our daily life, they also support a variety of 'beneficial uses' 1 (BUs), including amenities, mariculture, fisheries, cooling, toilet flushing, navigation, effluent discharge, sand borrowing and mud disposal. Figure 1 illustrates the abundance of different marine life supported by our marine waters.
Figure 1 Our marine waters support different habitats for marine life
We need to protect our marine waters to ensure they are fit for marine life growth and different human uses in a sustainable manner. Many overseas jurisdictions establish WQOs as the benchmark 2 to measure the "environmental health" of a water body. In general, waters with more sensitive uses, including sanctuaries for important species such as the Chinese White Dolphin, mariculture areas and bathing beaches, require higher level of protection (i.e. with more stringent WQOs), while water bodies with less sensitive uses such as navigation require relatively lower level of protection (i.e. with less stringent WQOs). Sensitive water bodies are mostly found in the eastern and southern waters.
The WQOs provide an objective and scientific basis for us to formulate and implement pollution control strategies, and to plan and develop infrastructure in a suitable and sustainable way, with a view to preventing unnecessary pollution and minimising impacts on the water quality.
3. Why WQO Review?
Our existing WQOs were introduced under the Water Pollution Control Ordinance (Chapter 358) 3, and first applied to the Tolo Harbour and Channel Water Control Zone (WCZ) 4 in 1982, and then extended to other WCZs from 1987 to 1996.
Over the years, there has been significant advancement in water science and technology. New uses of our waters, such as marine parks and reserves for conservation and education purposes, have also emerged. The community is more aware of the need to protect our environment, and the public expects a higher quality marine environment for recreational purposes, to secure a higher quality of life.
As a member of the global community, we also need to contribute to the sustainability of the marine environment through international cooperation. We have been taking a more active role in intergovernmental collaboration, for instance, implementing international agreements and treaties which aim at preventing pollution 5 and conserving marine resources, and participating in international fora such as the Asia-Pacific Economic Cooperation Forum.
In order to keep pace with global developments and scientific advances, this review is timely and it enables us to ensure that our water quality objectives are suitable for the long-term protection of our marine environment.
4. Key Issues of the Review
The logical first step in updating our WQOs is a review of existing WQOs, the local marine environment and overseas practices, in order to identify areas for improvements, the main protection priorities, and ways to develop suitable new WQOs. An in-depth review on each aspect will then be conducted to reflect the latest scientific knowledge and overseas best practices. Changes to the WQOs, or new WQOs, will then be assigned to the BUs identified for each water body. We will also examine the technical issues, benefits and socio-economic impacts associated with the implementation of the proposed changes before they are adopted.
We have already identified a number of key issues related to the existing WQOs, after a review of our marine environment and overseas best practices. The findings are shown in the paragraphs below. More technical details can be found in the "Technical Note" downloadable at the WQO Review Project Website 6.
Characteristics of our marine waters
Our marine waters change gradually from a sheltered, estuarine environment in the west, to an exposed, ocean environment in the east, with a transition zone in the middle. The freshwater flow of Pearl River affects the western and southern areas of the territory, and the influence is progressively reduced towards the east. The influence of the Pearl River flow, as shown in Figure 2, is greater during summer, when the flow is at its peak and rainfall is at its highest in the southern part of the mainland.
Figure 2 Our coastal waters are influenced by the Pearl estuary
Quality of our marine waters
Over the years, our routine monitoring of the marine waters has provided useful data for checking the compliance rates of the WQOs, and assessing the effectiveness of the sewage infrastructure programmes and pollution control measures put into place by the Government.
In 2008, the marine water quality in Hong Kong achieved 80% overall compliance 7 with the WQOs. For individual water bodies, the water quality in the eastern parts of Hong Kong, such as Mirs Bay and Port Shelter, is good overall, with a 100% rate of success in meeting our existing WQOs. Other parts of Hong Kong waters are not so good, such as Deep Bay, which only achieved a 40% rate of success.
EPD monitors 44 beaches located in different parts of the territory. The compliance with bathing WQO laid down for the beaches in 2008, based on the E.coli reading, was 83%, which is largely in line with that of the past couple of years. Beaches with the best quality are mainly located in the southern district of Hong Kong Island, Sai Kung, and Outlying Islands.
The levels of toxic substances in marine water, sediment and biological organisms generally met local and overseas standards for the protection of marine life and human health.
More details about the marine water quality monitoring, other monitoring programmes such as the "Beach Water Monitoring Programme" and the "Toxic Substances Monitoring Programme", and the monitoring data can be found on the EPD's website 8.
Observations on the existing WQOs
Our current WQOs were largely developed on the basis of our scientific knowledge, water quality conditions and social needs in the 1980s, with reference to the WQOs adopted by other countries. With reference to overseas best practices, we have a number of observations on the existing WQOs:
- Some WQOs may no longer be appropriate for today's conditions - for example, there is a single word-based or 'narrative' WQO for toxic substances, while other countries have now introduced numerical WQOs for individual toxic substances.
- High background levels of some chemicals leads to non-compliance – for example, non-compliance with the WQO for total inorganic nitrogen (TIN) has been observed in Deep Bay for some years due to the high background level, although algal growth (which is very often linked to high levels of certain nutrients) in the water body, is at a surprisingly low level.
- Two or more BUs co-exist in some water bodies – for example, Deep Bay is used for oyster culture and other sensitive marine uses, but is also close to urban developments.
- The existing WQOs may not be able to provide full protection for some BUs (e.g. mariculture), and are not available for new BUs (e.g. marine parks and reserves).
- We need to keep pace with the latest overseas trends in water quality management, such as:
- Use of biological objectives;
- Establishing nutrient WQOs with reference to background conditions;
- More common use of numerical WQOs;
- Other bacterial indicators for bathing waters.
We have made comparisons between our practice and overseas best practices, as shown in Tables 1 and 2.
Table 1 – Comparison between local and overseas best practices
| WQO PARAMETERS | LOCAL PRACTICE | OVERSEAS PRACTICE |
|---|---|---|
| Natural (e.g. pH, dissolved oxygen) | Narrative and numerical level | Narrative and numerical level |
| Nutrients (e.g. total inorganic nitrogen (TIN), phosphate, silicate, etc.) | Narrative, and a TIN WQO with numerical level | A range of nutrient parameters, each with numerical level |
| Chemical (including toxicants) | Narrative | Numerical level |
| Biological | None | Numerical level |
Table 2 – Comparison between WQO parameters for specific uses
| WQO PARAMETERS FOR SPECIFIC USE | LOCAL PRACTICE | OVERSEAS PRACTICE |
|---|---|---|
| Bathing Waters | Numerical level using E. coli | Numerical level using Enterococci alone, or both E. coli and Enterococci |
Mariculture
|
A WQO for E. coli with numerical level None |
Numerical level Some with numerical level |
The general methods adopted by different countries in coming up with (i) different types of WQOs, and (ii) WQOs for bathing water and mariculture, are discussed as follows. The derivation of WQOs is normally driven by the different water quality management approaches adopted by the various overseas jurisdictions as described above.
- WQOs for natural parameters – These parameters include pH, temperature, salinity, dissolved oxygen, etc, and the "Reference Site Approach" is commonly adopted for developing the numerical values concerned. The approach is to generate required values at measurement sites for each natural parameter, based on at least two years' data at a corresponding reference site 9, which has similar or the same biological make-up as the water body for which the WQO is to be established. This approach is commonly adopted by jurisdictions such as Australia, the EU, and the US.
- WQOs for nutrients – The primary purpose of setting nutrient-related WQOs is to control excessive growth of algae. The parameters concerned include nitrogen, silicate, and phosphate. Similar to the WQOs for natural parameters, the "Reference Site Approach" is in general adopted, by jurisdictions such as Australia, the EU, and the US in the derivation of nutrient-related WQOs. Other site-specific factors such as water current and light intensity, which contribute to excessive algal growth, will also be considered.
- WQOs for chemical parameters (and toxicants) – The "Risk Assessment Approach" aims at protecting 99%, 95%, 90%, or 80% of the marine species, while the "Full Protection Approach" is to protect 100% of the species for 100% of the time. These approaches are commonly adopted by countries such as Australia and the US. If toxicity data needed for setting the WQOs is not enough, the usual overseas practice is to adopt the "Assessment Factor Approach", which is to apply a "factor of safety" to the value derived from the toxicity data to cater for any uncertainty.
- Biological WQOs – These WQOs measure directly how resident species "behav" when their environment is exposed to pollution, and they complement other physical and chemical WQOs. The approach is to first collect baseline or 'normal' data of biological conditions concerning the types, abundance, distribution, composition and diversity of marine life in a certain water body. The next step is to develop a system such as an index or grading scale which can reflect changes in biological conditions with respect to the 'normal' conditions.
- WQOs for bathing waters – The "WHO Guidelines for Safe Recreational Water Environments" issued by the World Health Organisation (WHO) in 2003 suggests that intestinal enterococci is the best bacterial indicator of the relationship between bathing water pollution and common bathing illnesses, such as gastrointestinal illnesses, and acute febrile respiratory illnesses. The WHO Guidelines provide reference for countries to develop their own bathing water standards, taking into account local conditions such as acceptable risk level, public health data, environmental and socio-economic conditions.
- WQOs for mariculture – A number of countries such as Korea, Australia and the US rely on WQOs for protecting the growth and reproduction of cultured fish or shellfish. Some jurisdictions such as Australia and the US have produced WQOs for specific pollutants in the water, so that products harvested from these areas can meet established food standards. In conjunction with the WQOs, some jurisdictions adopt a further tier of control by setting standards for body tissues of the fish and shellfish.
5. Review Approaches
Based on our initial review, a list of parameters proposed for closer attention is shown in
Appendix A. In addition, we propose to adopt the general principles, and approaches set out below for in-depth review of the parameters:
a) General principles for WQO development include the following:
- Application of the Use-Protection Approach taking into account existing BUs;
- Application of Non-Degradation Approach to waters of high ecological value;
- Application of Risk Assessment Approach to protect at least 80% of species.
b) The best practice approach(es) for setting individual WQOs are set out below:
| WQO PARAMETERS | PROPOSED METHODS |
|---|---|
| Natural | Site-specific approach setting certain values for background data. |
| Nutrients | Site-specific approach, with trigger values for algal blooms, and taking into account background conditions. |
| Chemical (including toxicants) |
|
| Biological | Baseline 'normal' biological conditions will be assessed through monitoring programme, before identifying suitable indicators and parameters. |
| Bacterial indicator for Bathing Waters | By reference to the WHO's guidelines, the use of enterococci as a bacterial indicator will be explored. |
| For Mariculture (fish farming, shellfish cultivation, etc.) | Risk-based approach, and drawing on overseas and local references as appropriate. |
6. Your Views are Welcome
This WQO review is important in a number of aspects such as beneficial uses of marine waters, marine water quality management, marine conservation, coastal development, environmental impact assessment, and pollution control in Hong Kong. We would like to hear your views at this early stage, so as to develop a set of WQOs appropriate for Hong Kong in the decades to come. Specifically, we are keen to hear your views on the following questions:
| a) | what are your views on the key issues set out in section 4 above? |
| b) | what are your views on the beneficial uses and sensitive receivers set out in section 2? Are you aware of any other beneficial uses of waters that should be considered in this review? |
| c) | what are your views on the priority and level of protection for various beneficial uses, sensitive receivers and sensitive organisms that should be protected through the WQOs? |
| d) | in respect of Appendix A, what other types of WQOs or parameters should be considered in the next stage? |
| e) | what are your views on the review approaches as set out in section 5 above? |
| f) | what broad water quality management principles and WQO approaches should be considered in the next stage? |
Please send your comments to us before 31 December 2009 by one of the following means:
| Address: | WQO Review Environmental Protection Department Water Policy and Science Group 33/F, Revenue Tower 5 Gloucester Road Wan Chai, Hong Kong |
|---|---|
| By E-mail: | wqo_review@epd.gov.hk |
| Facsimile: | 2838 2155 |
Please note that the Government would wish, either in discussion with others or in any subsequent report, whether privately or publicly, to be able to refer to and attribute views submitted in response to this public engagement document. Any request to treat all or part of a response in confidence will be respected, but if no such request is made, it will be assumed that the response is not intended to be confidential.
Environmental Protection Department
September 2009
Appendix A: WQO Parameters or Indicators
| Nutrients-related |
|---|
| 1. The narrative nutrient WQO |
| 2. Total inorganic nitrogen |
| 3. One nitrogen-related parameter (e.g. Total nitrogen) |
| 4. One phosphorus-related parameter (e.g. Total phosphorus) |
| 5. Chlorophyll-a |
| 6. Silica |
| 7. Turbidity |
| 8. Dissolved Oxygen |
| Physical and Chemical |
|---|
| 9. Aesthetic Appearance (narrative) |
| 10. Dangerous Substances (narrative) |
| 11. Settleable Material (narrative) |
| 12. Colour |
| 13. Light penetration |
| 14. pH |
| 15. Salinity |
| 16. Suspended Solids |
| 17. Temperature |
| 18. Turbidity |
| 19. Dissolved Oxygen |
| 20. Arsenic |
| 21. Cadmium |
| 22. Chromium |
| 23. Copper |
| 24. Lead |
| 25. Mercury |
| 26. Nickel |
| 27. Silver |
| 28. Zinc |
| 29. Phenol |
| 30. Polycyclic Aromatic Hydrocarbons (PAHs) |
| 31. Tributyl-tin (TBT) |
| 32. Polychlorinated Biphenyls (PCBs) |
| 33. Dichlorodiphenyltrichloroethane (DDT) |
| 34. Dioxins |
| 35. Hexachlorobenzene |
| 36. Unionised Ammonia |
| 37. Cyanide |
| 38. Sulphide |
| 39. Surfactants |
| 40. Oil and Grease |
| 41. Total Petroleum Hydrocarbons |
| 42. Total Residual Chlorine |
| 43. Chlorination by-products |
| Microbiological |
|---|
| 44. E. coli |
| 45. Enterococci |
| 46. Faecal streptococci |
| 47. Clostridium perfringens |
| 48. Faecal coliforms |
1 Beneficial use (BU) refers to the planned use of a water body. A water body is fit for a specific BU, if it meets the relevant WQOs set for the BU.
2 These benchmarks, can be numerical or narrative, and include various parameters to describe the physical, chemical and biological properties of the marine environment.
3 Details can be found at https://www.elegislation.gov.hk/
4 Under the WPCO, if a specific water body is declared as a Water Control Zone (WCZ), all discharges and deposits within the WCZ are subject to licensing control. There are ten WCZs declared, covering all the marine waters of Hong Kong
5 For example, the Stockholm Convention on Persistent Organic Pollutants.
6 Link: https://www.epd.gov.hk/epd/english/environmentinhk/water/wqo_review/index.html
7 The overall compliance rate is based on the combined individual compliance rates of all monitoring stations for the four important marine WQOs, namely dissolved oxygen, total inorganic nitrogen, unionized ammonia, and E.coli.
8 Link: https://www.epd.gov.hk/epd/english/environmentinhk/water/hkwqrc/overview/index.html
9 Any site selected for reference purpose should be unimpaired or minimally impaired.
