EPD - Beach Water Quality

 

Beach Water Quality in Hong Kong 2010

Our Mission:

To safeguard the health and welfare of the community and meet conservation goals by working to achieve and maintain the Water Quality Objective for bathing beaches

[Photo: Hong Kong beaches are popular for both the local community and overseas tourists]

Introduction

Hong Kong is surrounded by sea with many beautiful beaches due to its long coastline. These beaches provide recreational space and attract millions of visitors each year.

[Photo: Kids enjoying summer fun at Shek O Beach]

The objective of the EPD’s Beach Water Quality Monitoring Programme is to monitor beach water quality and protect the health of the bathers. The background and details of EPD’s monitoring activities can be found on the EPD’s Homepage (http://www.epd.gov.hk) or its newly launched thematic website (http://www.beachwq.gov.hk).

[Photo: Blue sky, bright sunlight and clean water greet swimmers at Shek O Beach]

This report summarises the beach monitoring data collected in 2010, the gradings of the beaches and their compliance with the Water Quality Objective (WQO). It also highlights the water quality improvement observed over the last 25 years since the monitoring programme was implemented in 1986. In 2010, the EPD monitored 41 gazetted beaches and three non-gazetted beaches located in different parts of the territory. The gazetted beaches were monitored weekly during the bathing season from March to October, and the EPD staff made field observations and collected samples for laboratory analyses of E. coli bacteria. The EPD staff also took measurements of dissolved oxygen, pH, salinity, temperature and turbidity of beach waters.

[Photo: EPD inspectors monitor water quality at Deep Water Bay Beach]

[Photo: Bacterial testing of beach water at EPD’s laboratory]

Hong Kong’s beaches are assessed using a dual system: annual ranking and weekly grading based on the E. coli level in beach water, which indicates potential health risks associated with swimming. The annual ranking reflects the overall water quality of the beach over the entire bathing season, while the weekly grading denotes the recent water quality of the beach. Under the dual rating system, beaches are categorised into “Good”, “Fair”, “Poor” and “Very Poor”, and those ranked “Good” and “Fair” meet the WQO for bathing waters.

Annual Beach Ranking in 2010

In 2010, all 41 gazetted beaches in Hong Kong complied with the WQO. It is the first occasion which records 100% compliance with the WQO, since the monitoring programme began in 1986. This represents a noticeable improvement in compliance rate from the 93% recorded last year (2009) or the 83% recorded during the earlier six years (2003 to 2008). Twenty-three (or 56%) out of 41 gazetted beaches were ranked as “Good”, same as last year. Eighteen other beaches (44%) were ranked as “Fair”, and none as “Poor” or “Very Poor”.

[Photo: The scenic Clearwater Bay First Beach]

[Photo: Fun for all ages at Clearwater Bay Second Beach]

The beaches with “Good” water quality ranking were mainly located in the Southern District (Hong Kong Island South), Sai Kung area, and Outlying Islands. Nine out of 12 beaches in the Southern District were ranked as “Good” in 2010, Big Wave Bay, Hairpin and Rocky Bay Beaches were ranked as “Fair”. Of the nine beaches monitored on the Outlying Islands, eight were “Good” while Silver Mine Bay Beach was rated as “Fair”. In the Sai Kung area, five of the six beaches were “Good”. Among them, Hap Mun Bay Beach on Sharp Island was the cleanest gazetted beach in Hong Kong in 2010 in terms of overall E. coli levels. Only Silverstrand Beach was rated as “Fair”. On the western side, all six beaches along the Tuen Mun coast received a “Fair” ranking in 2010. In the Tsuen Wan area, Ma Wan Tung Wan Beach was ranked as “Good” in 2010 and was the only beach in the area open to swimmers. The water quality of the seven closed Tsuen Wan beaches has markedly improved in 2010 upon the full commissioning of the Advance Disinfection Facilities (ADF) in March 2010, which are designed to disinfect the treated effluent from the Stonecutters Island Sewage Treatment Works. Since all seven closed beaches had achieved “Fair” water quality ranking, the Government has planned to re-open four of these beaches to the public for swimming in 2011.

[Photo: An impressive view of the Ting Kau and Tsing Ma Bridges from Approach Beach]

The EPD also monitored three non-gazetted beaches in Hong Kong: Discovery Bay (a popular beach on Lantau Island), a sandy beach adjacent to Kiu Tsui Beach in Sai Kung, and a planned artificial beach in Lung Mei, Tai Po. Discovery Bay and the beach adjacent to Kiu Tsui Beach continued to be ranked “Good” in 2010. Lung Mei has dropped from “Fair” ranking in 2009 to “Poor” ranking in 2010. Public sewerage network is being extended to villages in the Lung Mei area, and planned drainage diversion and other pollution control measures will be implemented to improve the water quality in Lung Mei area in the next few years.

In summary, the rankings of gazetted beaches have improved in 2010: the compliance of bathing WQO has achieved a full (100%) compliance in 2010, compared with 93% in 2009 and 83% in the earlier six years (2003 to 2008). The improved compliance rate also indicated that the continued upgrading of the sewerage infrastructure and enforcement of environmental legislation have brought about gradual and sustained improvement of beach water quality in Hong Kong.

Weekly Beach Grading in 2010

The EPD issues weekly gradings of gazetted beaches which are open for swimming. The information is disseminated to the public through weekly press releases, the EPD’s website, the beach hotline and beach noticeboards.

[Photo: A typical water quality board at beach]

In 2010, the water quality of Southern District beaches was largely satisfactory. All ten gazetted beaches received mostly “Good” or “Fair” gradings in the bathing season, except for Big Wave Bay which was rated as “Poor” or “Very Poor” on several occasions after heavy rainstorms. South Bay, St. Stephen’s and Chung Hom Kok Beaches had the best water quality, achieving “Good” gradings on all rating occasions. The water quality of Sai Kung beaches was generally good. Hap Mun Bay and Trio Beaches achieved “Good” gradings over 90% of the rating occasions, while the other beaches were mostly “Good” or “Fair”. The water quality of the beaches in the Tuen Mun area was generally fine and nearly all graded as “Good” or “Fair”, except Castle Peak Beach which was rated as Grade 3 or Grade 4 on several occasions. The water quality of Ma Wan Tung Wan Beach in Tsuen Wan had shown positive signs of improvement, its gradings were all maintained at “Good” or “Fair”. The beaches on the Outlying Islands were generally ideal for swimming, with Hung Shing Yeh, Lo So Shing and Tong Fuk Beaches achieving 100% “Good” gradings. Cheung Chau Tung Wan and Upper Cheung Sha Beaches achieved “Good” gradings over 90% of the rating occasions.

[Photo: Hong Kong beaches offer respite from hustle and bustle of city life]

Water quality improvement measures for Tsuen Wan Beaches

All seven gazetted beaches in Tsuen Wan were closed to swimmers since 2003 due to poor and unstable water quality. They were Anglers’, Approach, Casam, Gemini, Hoi Mei Wan, Lido and Ting Kau Beaches. The poor and unstable water quality was due to pollution sources in the unsewered hinterlands and the fluctuating background bacterial levels in the marine waters off Tsuen Wan coast.

Map showing location of the seven closed beaches and Sham Tseng Sewage Treatment Works

The water quality improvement in recent years has been brought about through Government’s effort to provide sewerage along the coastal strip between Tsing Lung Tau and Ting Kau areas in phases. The successful full operation of the Sham Tseng Sewage Treatment Works in early 2005 marked an important milestone. Since 2003, the Government has progressively installed new public sewers in the beach hinterlands along Castle Peak Road at Tsing Lung Tau, Sham Tseng and Ting Kau areas. Through the completion of the sewerage improvement works along the Castle Peak Road in early 2010, and enforcement of environmental legislation, improvement of water quality of these closed beaches has become more discernable in the last couple of years, as reflected by the gradual improvement of the annual ranking over the last six years.

[Photo: Sham Tseng Sewage Treatment Works]

To further improve the water quality of Tsuen Wan beaches, the Government has been implementing the next stage of the Harbour Area Treatment Scheme (HATS Stage 2A), and successfully commissioned the Advance Disinfection Facilities on 1st March 2010 to disinfect the treated effluent from the Stonecutters Island Sewage Treatment Works. Coupled with the implementation of the sewerage improvement works and continuous pollution control efforts, the water quality in the area has shown clear signs of improvement in the 2010’s bathing season. As a result, the water quality of all seven closed Tsuen Wan beaches further improved and achieved “Fair” annual ranking in 2010.

[Photo: Full commissioning of Advance Disinfection Facilities at Stonecutters Island Sewage Treatment Works in March 2010]

The Government has striven to sustain improvement of the water quality of Tsuen Wan beaches. In 2011, four closed beaches, namely Approach, Casam, Hoi Mei Wan and Lido Beaches, will be re-opened to the public for swimming. When the beach facilities of the other three closed beaches: Anglers’, Gemini and Ting Kau Beaches, are upgraded, they could also be re-opened in the near future.

[Figure: Water quality trend lines of Approach and Lido Beaches annotated with milestones of some sewerage projects]

Progress and water quality trend in the last 25 years

The beach water quality monitoring programme was implemented in 1986, and significant development over the last 25 years is summarized in the table below.

Milestone of the Beach Water Quality Monitoring Programme

1986

Establishment of the Environmental Protection Department (EPD)

Implementation of EPD’s beach monitoring programme.

Bathing water quality standard of a median of 1,000 E. coli counts per 100 mL was adopted.

An annual ranking system based on the Hong Kong standards and the WHO guidelines was introduced.

Commencement of the epidemiological studies at local beaches.

1987

Establishment of a Microbiology Laboratory at EPD

Bacteriological analysis of beach samples carried out by EPD’s Microbiology Laboratory.

EPD adopted an improved Membrane Filtration method to replace the Multiple Tube method for E. coli analysis.

Launching of Beach Grading System

Beaches were classified into 3 grades according to the running median E. coli level of the 5 most recent sampling occasions.

EPD issued biweekly press release on beach water quality

1988

Revision of the Annual Ranking System

The annual ranking system was revised on the basis of the epidemiological study findings, and beaches were classified into 4 ranks according to the geometric mean E. coli level of all the samples collected during a bathing season.

The revised ranking system adopted the risk assessment approach based on the relationship between E. coli level and swimming-associated illness rates.

1990

Revision of the Beach Grading System

The bi-weekly beach grading system was revised on the basis of the epidemiological study findings, and beaches are classified into 4 grades according to the geometric mean E. coli level of the 5 most recent sampling occasions.

The revised grading system adopted the risk assessment approach based on the relationship between E. coli level and swimming-associated illness rates.

Re-opening of closed beach

Silver Mine Bay Beach was re-opened after its water quality showed sustained improvement.

1992

Establishment of the Water Quality Objective (WQO) for Bathing Water

The WQO (a geometric mean of 180 E. coli counts per 100 mL) for bathing water in Hong Kong is established.

Same description of water quality is adopted for both the ranking and grading systems, i.e. Good, Fair, Poor and Very Poor.

1996 – 2000

Revision of the Beach Monitoring Programme

EPD developed and adopted an improved and more rapid method for E. coli analysis to shorten the reporting time to 1.5 days.

EPD introduced a trigger level which classified beaches as Grade 4 (the worst grade) whenever the latest E. coli reading exceeded a high figure.

Enhancement of dissemination of beach information

Launching of webpage and telephone hotline on beach water quality.

Beach management authority started to disseminate beach gradings on noticeboards and to erect rainfall warning signs at beaches

EPD started to issue press releases on the beach grading on a weekly basis.

Re-opening of closed beach

Cafeteria Old Beach was re-opened after its water quality showed gradual and sustained improvement.

2001 – 2005

Enhancement of the Beach Monitoring Programme

EPD adopted a sampling regime based on random sampling approach, and conducted sampling also during weekends and public holidays, and the location and number of sampling points were refined to provide more comprehensive and representative information.

EPD conducting monitoring during winter months for 4 beaches which were open all year round.

Re-opening of closed beach

Castle Peak Beach was re-opened after its water quality showed gradual and sustained improvement.

2006 – 2010

Enhancement of the Beach Monitoring Programme

Monitoring procedures were further streamlined. Information on sudden deterioration of beach water quality leading to Grade 4 was disseminated to the public within 24 hours after sampling.

The beach website was further enhanced to provide more comprehensive information in a user-friendly manner.

Re-opening of closed beach

All 7 beaches in Tsuen Wan complied with the WQO for bathing water, and 4 beaches were planned to be re-opened in 2011.

There has been an overall improvement trend of beach water quality in Hong Kong. The percentage of beaches complying with the WQO has changed from 74% in 1986 (29 of 39 beaches) to 63% (26 of 41 beaches) in 1997, and 100% in 2010 (all 41 beaches).

Annual beach ranking of 1986, 1997 and 2010 compared

Year

WQO Compliant

WQO Non-compliant

Good

Fair

Poor

Very Poor

1986

23.1%(9)

51.3%(20)

17.9%(7)

7.7%(3)

1997

24.4% (10)

39.0% (16)

29.3% (12)

7.3% (3)

2010

56.1%(23)

43.9%(18)

-

-

( ) No. of beaches

Note: Two Beaches degazetted in 1995 were excluded from the calculation.

There was a drop in compliance rate in the mid-1990s due to population growth particularly in the new town areas. Since then, there has been progressive improvement in the last decade as a result of enforcement of environmental legislation, extension of the sewerage network and provision of new sewage treatment facilities across the territory including the beach hinterland. Major improvement measures implemented in the past 25 years are summarized in the following table.

Major improvement measures for the beaches over the past 25 years

1986 – 1990

Implementation of the Livestock Waste Control Scheme under the Waste Disposal (Livestock Waste) Regulation.

Declaration of the Southern Water Control Zone (WCZ) under the Water Pollution Control Ordinance (WPCO) and legislative enforcement.

Interception and diversion of polluted storm drains at beaches in Southern District.

Most beaches, particularly Silvermine Bay Beach

Southern beaches

Southern beaches

1991- 1995

Implementation of chemical waste control

Declaration of the North Western WCZ under WPCO and legislative enforcement

Diversion of polluted storm water drains away from Castle Peak Beach

Provision of public sewers for So Kwun Wat and Sam Shing Estate.

Commissioning of Stanley Sewage Treatment Works (STW)

All beaches

Tuen Mun beaches

Southern beaches

1996 - 2000

Full implementation of WPCO in all WCZs.

Commissioning of the Shek O Sewage Screening Plant and diversion of polluted storm water drains at Shek O Village

Completion of all major works under Southern Southern Sewerage Master Plan

Commissioning of the new 2 km long Pillar Point sewage submarine outfall

All beaches

Southern beaches

Tuen Mun beaches

2001 - 2005

Completion of HATS Stage 1

Provision of public sewers in Silverstrand area

Full operation of the Sham Tseng STW

Big Wave Bay, Shek O, Rocky Bay Beaches

Silverstrand Beach

Beaches along the Tsuen Wan coast

2006 - 2010

Commissioning of the Advance Disinfection Facilities at Stonecutters Island STW

Extension of the public sewerage network to the beach hinterland along Castle Peak Road

All Tsuen Wan beaches

Beaches along the Tsuen Wan coast

As a result of these measures, the percentage of beaches ranked ‘Good’ has more than doubled over the period, rising from just 23% in 1986 to 56% in 2010. Since 1999, the WQO compliance rate has been maintained at over 80%, a clear indication of sustained improvement in water quality. Between 1997 and 2010, out of the 41 gazetted beaches, those complying with the WQO have increased from 26 to 41 (63% to 100%). In the same period, the number of “Good” beaches has more than doubled from 10 to 23.

Annual beach ranking in 1997 and the marked improvement

over the last 3 years (2008, 2009 and 2010)

Year

WQO Compliant

WQO Non-compliant

Good

Fair

Poor

Very Poor

1997

24.4% (10)

39.0% (16)

29.3% (12)

7.3% (3)

2008

28.5(24)

24.4% (10)

17.1% (7)

-

2009

56.1%(23)

36.6%(15)

7.3%(3)

-

2010

56.1%(23)

43.9%(18)

-

-

( ) No. of beaches

The improvements made at various district in the last 25 years are significant, as illustrated in the story boxes in the next few pages. Silvermine Bay, Castle Peak, Repulse Bay Beaches were most remarkable as they have consistently complied with the WQO in recent years. All seven closed Tsuen Wan beaches met the WQO in 2010, compared to their non-compliance a few years ago. Back in the 1980s, many beaches were either closed (e.g. Cafeteria Old, Castle Peak and Silver Mine Bay Beaches) or on the verge of being closed (e.g. Middle Bay and Repulse Bay Beaches) because of their poor water quality. Through continuous effort of the Government to implement pollution abatement measures over the past 25 years, all Hong Kong’s beaches have now achieved the required standard for bathing waters.

Water quality trend lines of individual beaches over the last 25 years are included in this report to show the changes over the years. Fuller background and details of the beach monitoring programme are available at the EPD’s Homepage (http://www.epd.gov.hk) or the thematic website (http://www.beachwq.gov.hk), which provides user-friendly access to the annual beach reports published since 2000.

Four Story boxes

1. Marked improvement in water quality of beaches in Southern District:

Back in the 1980s, many of the 12 gazetted beaches in Southern District were not in good shape. Middle Bay and Repulse Bay Beaches could not meet the water quality objective (WQO) for bathing beaches and were on the verge of closing.

Government's actions:-

-Implemented pollution control legislation.

-Diverted polluting stormwater channels away from beaches.

-Built new sewage treatment facilities.

-Implemented public sewer connection programme in beach hinterlands.

-Now all Southern District beaches meet the bathing water quality objective.

These beaches provide good water quality and scenic environment for the public to enjoy.

2. Repulse Bay Beach:

In the late 1980s, the water quality of the beach was on the verge of closure, with annual geometric means of E. coli counts of over 400 count/100 mL, ranked as “Poor”.

Remedial measures were promptly taken by the Government:-

-Enforcing the pollution control legislation.

-Implementing the Hong Kong Island South Sewerage Master Plan to divert sewage and polluted storm flow away from the beach.

-Installing Dry Weather Flow (DWF) interceptors to intercept flow from polluted storm water drains.

3. Improvement of beach water quality enabling the re-opening of Castle Peak Beach:

Improvement programmes have successfully achieved clean water and made the beach safe for the public to swim.

-Castle Peak Beach has been reopened to swimmers since 2005 and has quickly become a popular destination for the public.

-The water quality of Castle Peak Beach continues to improve after its re-opening in 2005 as shown in its weekly gradings.

4. Silver Mine Bay Beach:

-A scenic beach on Lantau Island was closed from 1987 to 1989 due to unacceptable water quality.

-Annual geometric mean E. coli level was 2400 count/100 mL in 1987.

Major pollution sources:

-Livestock farms in Mui Wo. -Unsewered villages.

Government’s mitigation measures:
-Introduced Livestock Waste Control Scheme in Mui Wo in 1988 to stop illegal discharge from livestock farms.
-Commissioning of Mui Wo Sewage Treatment Works and implementing the wastewater control under the Water
Pollution Control Ordinance in 1989.

Improvement observed:
-Silver Mine Bay Beach started to comply with the Water Quality Objective in 1989.
-Generally maintained at "Fair" or above ranking since 1989.

Further improvement is expected...
Sewerage improvement works in Mui Wo area are on-going and should be completed in 2013. More houses in the hinterland will be connected to the public sewers.

Beaches monitored by the EPD

Southern
District

Sai Kung
District

Tsuen Wan
District

Tuen Mun
District

Islands District

Tai Po
District

Deep Water Bay Repulse Bay

Middle Bay

South Bay

Chung Hom Kok St. Stephen's

Stanley Main Turtle Cove

Shek O

Big Wave Bay
Hairpin*
Rocky Bay*

Kiu Tsui

Hap Mun Bay

Trio

Silverstrand

Clear Water Bay First
Clear Water Bay
Second

Kiu Tsui (New)**

Ma Wan Tung Wan
Anglers'*
Gemini*
Hoi Mei Wan* Casam*
Lido*
Ting Kau* Approach*

Butterfly
Castle Peak Kadoorie Cafeteria Old Cafeteria New
Golden

Silver Mine Bay

Pui O
Lower Cheung Sha Upper Cheung Sha

Tong Fuk
Cheung Chau Tung Wan

Kwun Yam 
Hung Shing Yeh
Lo So Shing
Discovery Bay**

Lung Mei**

* Closed beaches

** Non-gazetted beaches

Beach monitoring frequencies

Beach

Monitoring frequency per month

Bathing season *

Non-bathing season

Gazetted beaches open all year round**

at least 3 times

at least 3 times

Other gazetted beaches

at least 3 times

once

Non-gazetted beaches

at least 3 times

once

*  March to October

** Clear Water Bay Second, Deep Water Bay, Golden and Silverstrand Beaches

[Image of overview of various stages of the Beach Monitoring Programme]

Hong Kong's annual beach ranking system

Rank

E. coli counts per 100 mL*

Minor illness rate**
(Cases per 1,000 swimmers)

WQO Compliance

Good

<=24

Undetectable

Compliant

Fair

25-180

<=10

Poor

181-610

11-15

Non-compliant

Very Poor

>610

>15

* Geometric mean E. coli count calculated based on all data collected between March and October.

** Skin and gastrointestinal illnesses

Hong Kong's weekly beach grading system

Grade

Beach water quality

E. coli counts per 100 mL*

Minor illness rate **
(Cases per 1,000 swimmers)

1

Good

<=24

Undetectable

2

Fair

25-180

<=10

3

Poor

181-610

11-15

4

Very Poor

>610
or last reading >1,600

>15

* Unless otherwise indicated, the E. coli count represents the geometric mean of the 5 most recent sampling occasions.

** Skin and gastrointestinal illnesses

The 2010 Findings

Hong Kong’s gazetted beaches – 2010 annual ranking

Beach grading summary by district in 2010

Ranking and Grading Summary (in 2010 Bathing Season)

Southern District beaches

Sai Kung beaches

Tsuen Wan and Tuen Mun beaches

Outlying Islands beaches

Long-term Trend (1997 – 2010)

Annual beach rankings from 1997 to 2010

Annual beach ranking of 1997 and 2010 compared

Compliance with the Water Quality Objective at gazetted beaches, 1997-2010

Annual geometric mean E. coil levels by district. 1997-2010

Appendices

Appendix A - Annual geometric mean E. coli levels (1997 – 2010)

Appendix B - Beach visitor numbers, 2010

Appendix C - Physicochemical water quality data of gazetted beaches, 2010

Appendix D – Images of Long-term trend of beach water quality (1986 – 2010)

 

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Implementation of the Livestock Waste Control Scheme under the Waste Disposal (L