EPD - Beach Water Quality

Beach Water Quality in Hong Kong 2007

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.

 

Introduction

In 2007, beach goers in Hong Kong enjoyed the sunshine and blue sky of a drier than usual summer. The Environmental Protection Department (EPD) continued to monitor the water quality of bathing beaches and found it to be the best ever on record since the monitoring programme began in 1986. The objective of the programme is to monitor and improve beach water quality and protect the health of the bathers. The background and details of EPD's monitoring activities are found on the website (http://www.epd.gov.hk/epd/textonly/eindex.html).

[Photo of blue sky, bright sunlight and clean water greet bathers at Big Wave Bay Beach]

This report summarises the beach monitoring data collected in 2007, assessing beach gradings and compliance with the Water Quality Objective (WQO). In 2007, 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 2007

The beach water quality in 2007 was the best on record, while the number of "Good" beaches was the same as the highest level reached in 2004 (61% or 25 out of 41 gazetted beaches), no beach was ranked "Very Poor". Nine other beaches (22%) were ranked as "Fair" and seven (17%) as "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 four years (2003 to 2006).

[Photo of Repulse Bay Beach at dusk - a popular beach for locals and visitors alike]

The beaches with "Good" water quality ranking were mainly located in the Southern District (Hong Kong Island South), Sai Kung area, and Outlying Islands. All 12 beaches in the Southern District were ranked as "Good" in 2007, with Big Wave Bay and Rocky Bay Beaches improved from "Fair" to "Good". On the Outlying Islands, of the nine beaches monitored, eight were "Good" while Pui O Beach was rated as "Fair". The rankings of Cheung Chau Tung Wan and Silver Mine Bay Beaches improved from "Fair" to "Good" in 2007. Five of the six beaches in the Sai Kung area 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 2007. In the Tsuen Wan area, seven beaches had a "Poor" water quality ranking and were closed to swimmers. Ma Wan Tung Wan Beach ranked as "Fair" in 2007 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 2007, Lung Mei was ranked "Poor". Drainage diversion and pollution control measures should be able to improve water quality in the Lung Mei area in the next few years.

Overall, the beach water quality in 2007 has further improved with the highest number of "Good" beaches (25), the same as in 2004. Four beaches at Big Wave Bay, Cheung Chau Tung Wan, Rocky Bay and Silver Mine Bay have improved from "Fair" to "Good", Anglers' and Gemini Beaches in Tsuen Wan have upgraded from "Very Poor" to "Poor", while Pui O Beach has changed from "Good" to "Fair". The total rainfall in the 2007 bathing season was lower than that in 2006 (1,650 mm versus 2,440 mm ). This together with the long spell of sunny weather in July and early August have contributed favourably to the beach water quality. Continued improvements of sewage infrastructure and enforcement of environmental legislation have also helped reduce pollution and safeguard water quality of the beaches.

 

Weekly Beach Grading in 2007

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

[Photo of aerial view of Ma Wan Tung Wan Beach and Tsing Ma Bridge]

In 2007, the water quality of Southern District beaches was highly satisfactory. All ten gazetted beaches received either a "Good" or "Fair" grading in the bathing season, except on one occasion when Big Wave Beach was rated as "Poor" after a heavy storm. South Bay and Turtle Cove Beaches had the best water quality, achieving a "Good" grading throughout the season. The water quality of Sai Kung beaches was also excellent. Trio Beach achieved a "Good" grading during the bathing season, 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) generally fluctuated between "Fair" and "Poor". The beaches on the Outlying Islands were ideal for swimming. Three of the nine beaches, i.e. Lo So Shing, Tong Fuk and Upper Cheung Sha Beaches, maintained a "Good" grading throughout the bathing season; whereas the other beaches were mostly "Good" or "Fair".

Long-term 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 2007. In the same period, the number of "Good" beaches has more than doubled from 10 to 25.

Annual beach rankings of 1997 and 2007 compared

Year WQO Compliant WQO Non-compliant
Good Fair Poor Very Poor
1997 24.4% (10) 39.0% (16) 29.3% (12) 7.3% (3)
2007 61.0% (25) 21.9% (9) 17.1% (7) 0% (0)

( ) No. of beaches

The overall WQO compliance rate has been maintained at above 80% since 1999. The advances made at Silver Mine Bay and Tuen Mun beaches were 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.


Measures to improve Tsuen Wan Beaches

Seven gazetted beaches in Tsuen Wan remained closed to swimmers in 2007 due to poor water quality. These were Anglers', Approach, Casam, Gemini, Hoi Mei Wan, Lido and Ting Kau Beaches. Although a slight improvement in the annual ranking of two beaches (Anglers' and Gemini Beaches) was observed in 2007, the overall water quality in the area was still unsatisfactory. This 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 has started to implement 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. 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 early re-opening of Tsuen Wan beaches to the public for swimming.

[Photo of Stonecutters Island Sewage Treatment Works is the largest of its kind in the world]

[Photo of Trio Beach in Sai Kung offers a scenic environment with excellent water quality]


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 2007 Findings

Hong Kong's gazetted beaches - the 2007 annual ranking

Beach grading summary by district in 2007

 

Ranking and Grading Summary (in 2007 Bathing Season)

Southern District beaches

Sai Kung beaches

Tsuen Wan and Tuen Mun beaches

Outlying Islands beaches

 

Long-term Trend (1997 - 2007)

Annual beach rankings from 1997 to 2007

Annual beach ranking of 1997 and 2007 compared

Compliance with the Water Quality Objective at gazetted beaches, 1997-2007

Annual geometric mean E. coil levels by district. 1997-2007

 

Appendices

Appendix A - Annual geometric mean E. coli levels (1997 - 2007)

Appendix B - Beach visitor numbers, 2007

Appendix C - Physicochemical water quality data of gazetted beaches, 2007

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

 

 

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