EPD - Beach Water Quality

Beach Water Quality in Hong Kong 2006

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.

 

Introduction

The Environmental Protection Department (EPD) has implemented a comprehensive monitoring programme for bathing beaches in Hong Kong since 1986. The objective is to protect the public from possible health risks of swimming in polluted water. The background and details of the beach monitoring programme are available at the EPD's website (http://www.epd.gov.hk/epd/textonly/eindex.html), and from the report 20 Years of Beach Water Quality Monitoring in Hong Kong issued in May 2006 (also accessible through the website).

[Photo of Repulse Bay Beach - an oasis of calm in the busy city]

In 2006, the EPD monitored 41 gazetted beaches and two non-gazetted beaches in Hong Kong. These beaches were monitored at least three times per month during the bathing season (March to October). Water samples were collected and tested for the bacteria E. coli at the EPD's Environmental Microbiology Laboratory. Other water quality parameters measured in the field and laboratory included: water temperature, dissolved oxygen, turbidity, pH and salinity.

Hong Kong's beaches are rated by a dual system: annual ranking and weekly grading based on the E. coli level in beach water, which indicates possible health risks associated with swimming. The annual ranking reflects the overall water quality of a beach in the entire bathing season, while the weekly grading denotes recent water quality of the beach. Under the system, beaches are grouped into "Good", "Fair", "Poor" and "Very Poor", and those ranked as "Good" and "Fair" meet the Water Quality Objective (WQO) for bathing water.

 

Annual Beach Ranking in 2006

In 2006 the percentage of beaches complying with the WQO was 83%, the same as in the previous three years (2003 to 2005). Of the 41 gazetted beaches, 22 (or 54 %) were ranked as "Good", 12 (29%) as "Fair", five (12%) as "Poor" and two (5%) as "Very Poor".

[Photo of Big Wave Bay Beach - a paradise for wind-surfers]

The "Good" water quality beaches were mainly located in the Southern District (Hong Kong Island South), Sai Kung, and Outlying Islands. Ten out of the 12 beaches in the Southern District were ranked as "Good", and only two (Big Wave Bay and Rocky Bay Beaches) as "Fair". On the Outlying Islands, among the nine beaches monitored by the EPD, seven were ranked as "Good", the rest (Cheung Chau Tung Wan and Silver Mine Bay Beaches) were "Fair". Of the six beaches in Sai Kung, five were "Good", and Silverstrand Beach was the only one ranked "Fair"; however, a steady decrease of E. coli level was observed at Silverstrand Beach in the last few years, indicating an improvement in water quality. Monitoring data show that all six beaches in Tuen Mun scored a "Fair" ranking in 2006. On the Tsuen Wan coast, seven beaches with "Poor" or "Very Poor" rankings were closed to swimmers due to poor water quality. Ma Wan Tung Wan Beach was the only beach open in the area and it was ranked as "Fair" in 2006. The Government is taking active measures to improve the water quality of Tsuen Wan beaches.

[Photo of Stanley Main Beach - bathers enjoying the broad clean sand]

Two non-gazetted beaches were monitored by the EPD: Discovery Bay, a popular beach on Lantau Island, and Lung Mei, an artificial beach under planning in Tai Po. These two beaches were ranked "Good" and "Fair" respectively in 2006.

Overall, the beach water quality in 2006 was largely stable. Compared with 2005, the ranking of Cheung Chau Tung Wan Beach has changed marginally from "Good" to "Fair", while Approach, Casam, Hoi Mei Wan and Lido Beaches in Tsuen Wan from "Very Poor" to "Poor". The changes were generally within the normal range of water quality fluctuation of these beaches.

 

Weekly Beach Grading in 2006

The EPD issued gradings for the beaches when they were open to the public for swimming. These gradings were disseminated through daily updated webpages, telephone hotline, beach noticeboards and weekly press releases.

[Photo of Clear Water Bay First Beach - a beach in picturesque landscape]

The water quality of Sai Kung beaches was excellent. All six gazetted beaches maintained either "Good" or "Fair" gradings throughout the bathing season. Trio Beach was the best of all, achieving "Good" grading throughout the season. Beach gradings in the Southern District were also highly satisfactory. Nine out of the 10 beaches consistently achieved "Good" or "Fair" gradings, while Big Wave Bay Beach attained such gradings on over 80% of the sampling occasions. Tuen Mun beaches were mostly graded as "Fair". The gradings of the only open beach in Tsuen Wan (Ma Wan Tung Wan Beach) were more variable, mostly fluctuating between "Fair" and "Poor". The beaches on the Outlying Islands were ideal for swimming. Two out of the nine beaches, namely Lower Cheung Sha and Hung Shing Yeh Beaches, maintained a "Good" grading throughout the bathing season. Most of the other beaches maintained "Good" or "Fair" gradings, while Silver Mine Bay Beach attained such gradings in over 90% of the sampling occasions.

[Photo of Hung Shing Yeh Beach achieved 100% "Good" grading in 2006]

The number of "Grade 4 " incidents has been reduced from 11 in 2005 to four in 2006. Whenever a "Grade 4 " was issued, the beach would be closed to swimmers immediately and the EPD would undertake investigation and closely monitor the water quality. The decrease in "Grade 4 " incidents in 2006 might be related to pollution reduction, as well as a lower amount of rainfall 2,440 mm in 2006 versus 3,180 mm in 2005) during the bathing season.

 

Beach water quality trend in the last 10 years (1997 to 2006)

The number of gazetted beaches complying with the WQO has increased from 26 out of 41 (63%) in 1997 to 34 (83%) in 2006. In the same period, the number of "Good" beaches has more than doubled from 10 (24%) to 22 (54%). Since 1999, the number of beaches complying with the WQO has been maintained at above 80%. The improvement over the past decade was attributed to strict enforcement of environmental legislation, extension of the sewerage network and enhanced sewage treatment facilities in the beach hinterlands. The advances made at Silver Mine Bay and Tuen Mun beaches were most noticeable.

 

Measures to improve Tsuen Wan beaches

Seven gazetted beaches in Tsuen Wan remained closed in 2006 due to poor water quality. These were Anglers', Approach, Casam, Gemini, Hoi Mei Wan, Lido and Ting Kau Beaches. Although a slight upgrade in the annual rankings of four beaches was observed in 2006, the water quality in the area was generally poor and highly variable. This was due to pollution in the unsewered hinterlands and high background bacterial levels in the marine water off the Tsuen Wan coast.

To improve the water quality of the Tsuen Wan beaches, the Government is working on the next stage of the Harbour Area Treatment Scheme (HATS Stage 2A), and plans to disinfect effluent from the Stonecutters Island Sewage Treatment Works by 2009, subject to the support of the community for full recovery of the operating cost through sewage charges. The extension of public sewers and connection of unsewered villages along Castle Peak Road (near the Tsuen Wan beaches) is on-going. With the proposed sewerage works and continued pollution control measures, the water quality of the Tsuen Wan beaches should improve substantially in the next few years. This would prepare the way for the re-opening of the beaches to the public for swimming.

[Photo of Ma Wan Tung Wan Beach - the only open beach in Tsuen Wan District]

 

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

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 2 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 2006 Findings

Hong Kong's gazetted beache - the 2006 annual ranking

Beach grading summary by district in 2006

 

Ranking and Grading Summary

Southern District Beaches

Sai Kung District Beaches

Tsuen Wan and Tuen Mun District Beaches

Outlying Islands District Beaches

 

Ten Year Trend (1997 - 2006)

Annual beach ranking over the last 10 years

Annual beach ranking of 1997 and 2006 compared

Compliance with the Water Quality Objective at gazetted beaches, 1997-2006

Annual geometric mean E. coil levels by district. 1997-2006

 

Appendices

Appendix A - Annual geometric mean E. coli levels over 10 years

Appendix B - Beach visitor numbers, 2006

Appendix C - Physicochemical water quality data of gazetted beaches, 2006

Appendix D - Images of water quality trend lines of beaches over 10 years

 

 

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