EPD - Beach Water Quality

Beach Water Quality in Hong Kong 2008


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 at the beach: Fun and exercise for all ages.]





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 of Blue sky, bright sunlight and clean water at Lower Cheung Sha Beach]


This report summarises the beach monitoring data collected in 2008, and the gradings of the beaches and their compliance with the Water Quality Objective (WQO).  In 2008, 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, took measurements such as water temperature and dissolved oxygen, and collected samples for further laboratory tests for the faecal bacteria E. coli and other water quality parameters (pH, salinity and turbidity).


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 in the 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 2008


The beach water quality in 2008 was generally good despite the summer being exceptionally wet, especially when compared with the particularly dry summer of 2007.  The rainfall of 2,940 mm during the bathing season from March to October 2008 was much higher than the 1,650 mm in the corresponding period in 2007.  It is worth-mentioning that the monthly total rainfall of 1,350 mm in June 2008 is a new monthly rainfall record for Hong Kong since record began in 1884.


As pointed out in our previous reports, heavy rainfall can lower beach water quality, in cases where it washes pollutants from beach hinterlands and causes septic tanks and soakaway sewerage systems to overflow and run into the sea.  Despite of the exceptionally high rainfall in 2008, most beaches remained open and water quality was by and large good.  Twenty-four (or 59%) out of 41 gazetted beaches were ranked as “Good”, slightly down from 25 last year.  Ten other beaches (24%) were ranked as “Fair”, seven (17%) as “Poor”, and none as “Very Poor”.  In terms of WQO compliance, thirty-four (or 83%) of the 41 gazetted beaches in Hong Kong complied with the WQO, the same as in the previous five years (2003 to 2007).


[Photo of Repulse Bay Beach offers respite from busy city life]


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 2008, 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”.  The ranking of Pui O Beach improved from “Fair” in 2007 to “Good” in 2008.  The cleanest gazetted beach in Hong Kong in 2008 in terms of overall E. coli levels was Hung Shing Yeh Beach on Lamma Island.  In the Sai Kung area, five of the six beaches were “Good” with Silverstrand Beach being the only one ranked as “Fair”; however, the E. coli levels of this beach have been decreasing in the last few years, indicating a steady improvement in water quality.  On the western side, all six beaches along the Tuen Mun coast received a “Fair” ranking in 2008.  In the Tsuen Wan area, seven beaches had “Poor” water quality rankings and were closed to swimmers.  Ma Wan Tung Wan Beach ranked as “Fair” in 2008 and was the only beach open to the swimmers in the Tsuen Wan area.  The Government is currently taking active measures to improve the water quality of Tsuen Wan beaches.


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.  While Discovery Bay and the beach adjacent to Kiu Tsui Beach were ranked “Good” in 2008, Lung Mei was ranked “Poor”.  Drainage diversion and pollution control measures will be implemented to improve water quality in Lung Mei area in the coming few years.


To sum up, the broader picture of beach rankings has remained consistent over the past couple of years: the compliance of bathing WQO remains steady at 83%, and it has not been affected by the fluctuations of the exceptionally dry and wet summers of 2007 and 2008 respectively.  It demonstrates that continued improvements of sewage infrastructure and enforcement of environmental legislation have lessened the effect of polluted surface runoff on Hong Kong beaches even under heavy rain storms.



Weekly Beach Grading in 2008


The EPD issues weekly gradings for gazetted beaches which are open for swimming.  The information is disseminated to the public on the EPD’s website, the beach hotline, beach noticeboards and through weekly press releases.  The EPD’s website was significantly enhanced in 2008 to make it more user-friendly.


In 2008, the water quality of Southern District beaches was highly satisfactory.  All ten gazetted beaches received mainly “Good” or “Fair” gradings in the bathing season, except on a few occasions when Big Wave Bay, Deep Water Bay and Shek O Beaches were rated as “Poor” after heavy rain storms.  South Bay and Turtle Cove Beaches had the best water quality, achieving a “Good” grading in over 80% of the rating occasions.  The water quality of Sai Kung beaches was also very good.  Hap Mun Bay Beach achieved “Good” grading 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 mostly graded as “Fair”.  The gradings of the only open beach in Tsuen Wan (Ma Wan Tung Wan Beach) were mostly maintained at “Fair”, while it occasionally also fluctuated between “Good” and “Poor”.  The beaches on the Outlying Islands were generally ideal for swimming, with Hung Shing Yeh Beach on Lamma Island having a “Good” grading over 95% of the rating occasions.


[Photo of aerial view of Hap Mun Bay Beach]

[Photo of aerial view of Lo So Shing Beach]



Water quality trend


There has been a steady improvement of 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 34 (63% to 83%) between 1997 and 2008.  In the same period, the number of “Good” beaches has more than doubled from 10 to 24.


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)


58.5% (24)

24.4% (10)

17.1% (7)

0% (0)

( ) No. of beaches


The overall WQO compliance rate has been maintained at above 80% since 1999.  The improvement made at Silver Mine Bay and Tuen Mun beaches was most noticeable as they have consistently complied with the WQO in recent years.  The improvement was attributed to the 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 also 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).



Measures to improve Tsuen Wan Beaches


Seven gazetted beaches in Tsuen Wan remained closed to swimmers in 2008 due to poor water quality.  They were Anglers’, Approach, Casam, Gemini, Hoi Mei Wan, Lido and Ting Kau Beaches.  Their annual rankings remained the same as 2007, while the overall water quality in the area was still unsatisfactory.  The absence of beaches being rated as “Very Poor” in two consecutive bathing seasons was, however, an encouraging sign.  The poor water quality was due to pollution in the unsewered hinterlands and high background bacterial levels in the marine waters off Tsuen Wan coast.


To improve the water quality of Tsuen Wan beaches, the Government is implementing the next stage of the Harbour Area Treatment Scheme (HATS Stage 2A), and aims to disinfect effluent from the Stonecutters Island Sewage Treatment Works by the end of 2009.  Moreover, the extension of the public sewers and connections to unsewered villages along Castle Peak Road is on-going.  With the proposed sewerage works and continuous pollution control efforts, the water quality in the area is expected to improve substantially in the next few years.  This would pave the way for the re-opening of Tsuen Wan beaches to the public for swimming.


[Photo of Approach Beach along the Tsuen Wan coastline]


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 2008 Findings


Hong Kong’s gazetted beaches – 2008 annual ranking

Beach grading summary by district in 2008



Ranking and Grading Summary (in 2008 Bathing Season)


Southern District beaches

Sai Kung beaches

Tsuen Wan and Tuen Mun beaches

Outlying Islands beaches



Long-term Trend (1997 – 2008)


Annual beach rankings from 1997 to 2008

Annual beach ranking of 1997 and 2008 compared

Compliance with the Water Quality Objective at gazetted beaches, 1997-2008

Annual geometric mean E. coil levels by district. 1997-2008





Appendix A - Annual geometric mean E. coli levels (1997 – 2008)

Appendix B - Beach visitor numbers, 2008

Appendix C - Physicochemical water quality data of gazetted beaches, 2008

Appendix D – Images of Long-term trend of beach water quality (1986 – 2008)


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