EPD - Beach Water Quality


Beach Water Quality in Hong Kong 2009

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: EPD inspectors monitor water quality at Middle Bay Beach.]


The objective of the 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 website


[Photo: Blue sky, bright sunlight and clean water greet swimmers at Hong Kong beaches.]

This report summarises the beach monitoring data collected in 2009, and the gradings of the beaches and their compliance with the Water Quality Objective (WQO). In 2009, the EPD monitored 41 gazetted beaches and three non-gazetted beaches located in different parts of the territory. The monitoring frequency was at least three times a month during the bathing season from March to October. During monitoring, 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.

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.

 [Photo: A typical water quality grading board at the beach.]

Annual Beach Ranking in 2009

The beach water quality in 2009 was generally fine. Twenty-three (or 56%) out of 41 gazetted beaches were ranked as “Good”, slightly down from 24 last year. Fifteen other beaches (37%) were ranked as “Fair”, three (7%) as “Poor”, and none as “Very Poor”. In terms of WQO compliance, thirty-eight (or 93%) of the 41 gazetted beaches in Hong Kong complied with the WQO. This represents a significant surge in compliance rate from the 83% in the previous six years (2003 to 2008), and it is also the highest compliance rate since the monitoring programme began in 1986.

[Photo: Fun for all ages at Shek O 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. Eleven out of 12 beaches in the Southern District were ranked as “Good” in 2009, only Big Wave Bay Beach was 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, four of the six beaches were “Good”. Among them, Hap Mun Bay Beach on Sharp Island is the cleanest gazetted beach in Hong Kong in 2009 in terms of overall E. coli levels. Clear Water Bay Second Beach and Silverstrand Beach were rated as “Fair”. On the western side, all six beaches along the Tuen Mun coast received a “Fair” ranking in 2009. In the Tsuen Wan area, Ma Wan Tung Wan Beach ranked as “Fair” in 2009 and was the only beach open to swimmers in the Tsuen Wan area. The water quality of the seven closed Tsuen Wan beaches has shown signs of improvement in 2009. Four of the seven beaches had achieved “Fair” water quality rankings, but the other beaches remained at “Poor” ranking. The Government is currently taking active measures to further improve the water quality of Tsuen Wan beaches and to ensure their early re-opening to the public for swimming.

[Photo: An impressive view of the Ting Kau and Tsing Ma Bridges from Lido 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 2009. Lung Mei has improved from “Poor” in 2007 and 2008 to “Fair” in 2009. Extension of public sewerage network to Lung Mei village area is underway, drainage diversion and pollution control measures will be implemented to improve the water quality in Lung Mei area in the coming years,

In summary, the beach rankings have improved in 2009: the compliance of bathing WQO has surged from 83% achieved in the last six years (2003 to 2008) to a record high of 93% in 2009. The continued upgrading of sewage infrastructure and enforcement of environmental legislation would bring about gradual improvement of beach water quality in Hong Kong. We also observed that the relatively dry summer in 2009 contributed to the beach water quality improvement, noting that the total rainfall of 2,070 mm during the bathing season from March to October in 2009 was much lower than the 2,940 mm in the corresponding period in 2008.

  Weekly Beach Grading in 2009

The EPD issues weekly gradings for 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: Golden Beach opens year round for swimmers]

In 2009, the water quality of Southern District beaches was highly satisfactory. All ten gazetted beaches received “Good” or “Fair” gradings in the bathing season, except on a few occasions when Big Wave Bay and Chung Hom Kok Beaches were rated as “Poor” or “Very Poor” after heavy rain storms. South Bay, St. Stephen’s and Turtle Cove Beaches had the best water quality, achieving “Good” gradings in over 95% of the rating occasions. The water quality of Sai Kung beaches was generally very 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 better than last year’s and nearly all graded as “Good” or “Fair”, except a “Poor” grading was observed once at Butterfly Beach. The gradings of Ma Wan Tung Wan Beach in Tsuen Wan were mostly maintained at “Fair”, while the gradings occasionally also fluctuated between “Good” and “Poor”. The beaches on the Outlying Islands were generally ideal for swimming, with Tong Fuk Beach on Lantau Island achieving 100% “Good” gradings. Kwun Yam, Hung Shing Yeh, Lo So Shing and Upper Cheung Sha Beaches achieved “Good” gradings over 95% of the rating occasions.

[Photo: Kwun Yam Beach offers respite from hustle and bustle of city life.]

Water quality trend

There has been a steady improvement in beach water quality in Hong Kong in the last decade. Out of the 41 gazetted beaches, those complying with the WQO have increased from 26 to 38 (63% to 93%) between 1997 and 2009. In the same period, the number of “Good” beaches has more than doubled from 10 to 23.

Annual beach rankings of 1997 and 2008 compared


WQO Compliant

WQO Non-compliant




Very Poor


24.4% (10)

39.0% (16)

29.3% (12)

7.3% (3)


56.1% (23)

36.6% (15)


0% (0)

( ) No. of beaches

The overall WQO compliance rate has been maintained at above 80% since 1999. The compliance rate has soared to a record high of 93% in 2009. The improvements made at Castle Peak and Silver Mine Bay Beaches (see details in story boxes in the next two pages) were most noticeable as they have consistently complied with the WQO in recent years. Four out of the seven closed Tsuen Wan beaches met the WQO in 2009, compared to none in 2008. The improvement was attributed to enforcement of environmental legislation, extension of the sewerage network and enhanced sewage treatment facilities in the beach hinterlands.

Water quality trend lines of individual beaches over the last two decades (since 1986 when the monitoring programme began) are included in this report to show the changes over the years. Background and details of the beach monitoring programme are available at the EPD’s website, and from the report “20 Years of Beach Water Quality Monitoring in Hong Kong” issued in 2006 (also accessible through the website).

Two Story boxes

1. Improvement of beach water quality enabling the re-opening of Castle Peak Beach Information excerpted from:


2.          Silver Mine Bay Beach Information excerpted from:


Measures to improve Tsuen Wan Beaches

 Seven gazetted beaches in Tsuen Wan remained closed to swimmers in 2009 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 fluctuating background bacterial levels in the marine waters off Tsuen Wan coast. Nevertheless, we observed some improvements in 2009: no beach in Tsuen Wan is ranked as “Very Poor” in three consecutive bathing seasons and four of them, namely, Casam, Hoi Mei Wan, Lido and Ting Kau Beaches, had improved from the annual ranking of “Poor” in 2008 to “Fair” in 2009.

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

The above improvements in recent years are achieved through Government’s effort to provide sewerage along the coastal strip between Tsing Lung Tau and Ting Kau areas in phases and to step up enforcement actions in the areas. The successful full operation of the Sham Tseng Sewage Treatment Works in early 2005 was an important milestone. Since then, 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, thus reducing polluted discharges to the nearby bathing waters. With the Government’s continuous effort in providing new public sewers in phases along the Castle Peak Road and in enforcing environmental legislation, improvement of water quality of these closed beaches has become more discernable in the last couple of years, as reflected by the changes in the annual ranking over the last five years.

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 began the testing and commissioning of the Advance Disinfection Facilities in late 2009 to disinfect effluent from the Stonecutters Island Sewage Treatment Works. Moreover, the extension of the public sewers to the beach hinterlands along Castle Peak Road has been completed in early 2010, and connections to unsewered villages or developments to these sewers are on-going. With the implementation of these sewerage improvement works and continuous pollution control efforts, the water quality in the area has shown some early signs of improvement. The Government is striving to further improve the water quality of Tsuen Wan beaches and paving the way for their early re-opening to the public for swimming.

Advance Disinfection Facilities at Stonecutters Island Sewage Treatment Works

To summarise, the water quality of four of the seven closed Tsuen Wan beaches, namely Casam, Hoi Mei Wan, Lido and Ting Kau Beaches had improved from the annual ranking of “Poor” in 2008 to “Fair” in 2009. The relatively dry summer could also be a contributing factor to the observed improvement in 2009. The EPD will continue to closely monitor the seven beaches in the coming bathing season in order to ascertain that these improvements are indeed sustainable and that they could meet the WQO.

Beaches monitored by the EPD


Sai Kung

Tsuen Wan

Tuen Mun

Islands District

Tai Po

Deep Water Bay Repulse Bay

Middle Bay

South Bay

Chung Hom Kok St. Stephen's

Stanley Main Turtle Cove

Shek O

Big Wave Bay
Rocky Bay*

Kiu Tsui

Hap Mun Bay



Clear Water Bay First
Clear Water Bay

Kiu Tsui (New)**

Ma Wan Tung Wan
Hoi Mei Wan* Casam*
Ting Kau* Approach*

Castle Peak Kadoorie Cafeteria Old Cafeteria New

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


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


Non-gazetted beaches

at least 3 times


*  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


E. coli counts per 100 mL*

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

WQO Compliance












Very Poor



* 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


Beach water quality

E. coli counts per 100 mL*

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














Very Poor

or last reading >1,600


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

** Skin and gastrointestinal illnesses

The 2009 Findings

Hong Kong’s gazetted beaches – 2009 annual ranking

Beach grading summary by district in 2009

Ranking and Grading Summary (in 2009 Bathing Season)

Southern District beaches

Sai Kung beaches

Tsuen Wan and Tuen Mun beaches

Outlying Islands beaches

Long-term Trend (1997 – 2009)

Annual beach rankings from 1997 to 2009

Annual beach ranking of 1997 and 2009 compared

Compliance with the Water Quality Objective at gazetted beaches, 1997-2009

Annual geometric mean E. coil levels by district. 1997-2009


Appendix A - Annual geometric mean E. coli levels (1997 – 2009)

Appendix B - Beach visitor numbers, 2009

Appendix C - Physicochemical water quality data of gazetted beaches, 2009

Appendix D – Images of Long-term trend of beach water quality (1986 – 2009)

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