 |
| A
gazetted beach - Butterfly Beach |
2.1 Since 1986,
EPD has implemented a series of measures
to safeguard the health of bathers
including a comprehensive programme
to monitor the water quality of bathing
beaches. Currently, 41 gazetted and
9 non-gazetted beaches located in
six different districts are being
monitored by EPD (Figure 2.1).
 |
| A
non-gazetted beach - Discovery
Bay Beach |
2.2 The
gazetted beaches are managed by
the Leisure and Cultural Services
Department (LCSD) which is also
responsible for the collection of
floating refuse within the gazetted
beach area (Appendix 2). Nine non-gazetted
beaches are also monitored by EPD
because of their popularity (e.g.
Discovery Bay Beach) or their potential
to be gazetted in the longer term.
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|
|
|
Figure
2.1 Location
of beaches in Hong Kong
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|
2.3 The
water quality of these 50 beaches
is monitored regularly throughout
the year and at a higher frequency
during the summer months. The monitoring
results are disseminated to the public
through various channels such as the
weekly press release, beach water
quality hotline and Internet webpage.
Water Quality
Objective
2.4 A
Water Quality Objective (WQO) for
bathing water has been established
under the Water Pollution Control
Ordinance since 1992 to safeguard
the health of bathers. The established
WQO is based on the findings of the
epidemiological studies conducted
in the late 1980s by EPD and the local
academics. Results of the study indicate
that among all the faecal indicators,
E. coli has the highest correlation
with swimming-associated illness rates
and hence is the best faecal indicator
to estimate the health risks of swimming
at the beaches of Hong Kong.
 |
| Equipment
and accessories for beach water
sampling |
2.5 The
WQO states that the level of E.
coli should not exceed 180 per
100mL calculated as the geometric
mean of all samples collected during
the bathing season from March to
October. Samples should be taken
at least three times a month at
intervals of between 3 and 14 days.
This WQO applies to the bathing
beach subzones of all Water Control
Zones in Hong Kong.
 |
| Beach
water sampling |
MonitoringProgramme
2.6 The
beach monitoring programme has been
in place for 16 years and is constantly
reviewed to safeguard the health of
bathers. It is designed to serve the
following functions:
-
To assess
compliance with the WQO: Based
on the monitoring information,
the Authority will be able to
determine whether the standard
for bathing water is being met.
-
To detect
any change in beach water quality:
Monitoring can provide early warning
of beach water pollution so that
any potential pollution problem
can be resolved more easily at
an early stage.
-
To identify
polluted beaches that need remedial
actions: Based on the monitoring
results, the Authority can identify
polluted beaches and set priorities
to take remedial actions for improving
the beach water quality.
-
To evaluate
pollution abatement programmes:
Monitoring provides the information
needed to determine the efficacy
of beach-related improvement measures
such as provision of sewerage
or enforcement of relevant legislation.
-
To decide
on the opening of beaches: Monitoring
provides the information on water
quality trends for gazetted beaches
so that LCSD can decide on the
opening of beaches.
-
To advise
the public on the beach water
quality status: Monitoring helps
to answer such question from the
public as "Is the beach suitable
for swimming?"
 |
| Turbidity
measurement of beach water sample |
|
| |
Beach
|
Monitoring
frequency
|
|
Bathing
season
|
Non-bathing
season
|
| |
Gazetted
beaches opened all
year round*
|
Once
per week
|
Once
per week
|
| |
Other
gazetted beaches
|
Once
per week
|
1-2
times per month
|
| |
Non-gazetted
beaches |
2-3
times per month
|
Once
per month
|
|
Table
2.1 Beach
monitoring frequencies
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|
*
Deep Water Bay, Golden and Clear
Water Bay Second Beaches
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|
2.7 All
the gazetted beaches are monitored
at least once per week while the non-gazetted
beaches are monitored at 2-3 times
per month during the bathing season.
Samples are collected on random days
including weekends and public holidays
to ensure that the water quality information
collected is not biased. During the
non-bathing season, the three gazetted
beaches, viz. Deep Water Bay, Golden
and Clear Water Bay Second Beaches
which are opened all year round will
also be monitored once per week, while
all other beaches are monitored at
least once a month. The sampling frequencies
are summarized in Table 2.1.
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|
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|
Figure
2.2 The operational
procedures of the Beach Monitoring
Programme
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|
|
2.8 Subsurface
seawater samples are collected from
the bathing area within the boom at
thigh to waist water depth for E.
coli analysis and measurement
of pH, turbidity and salinity. Water
temperature and the dissolved oxygen
content are measured on site using
portable analyser. Weather and beach
conditions including any abnormal
observations are recorded. The operational
procedures of the monitoring programme
are depicted in Figure 2.2.
 |
Beach Rating
Systems
2.9 EPD
has developed two rating systems,
viz. the annual ranking and weekly
grading systems, in order to assess
the annual beach water quality and
to provide timely information on
the latest beach water quality to
the public during the bathing season
respectively. They reflect the respective
long-term and short-term bacteriological
water quality trends. Both rating
systems classify beaches into four
categories according to their bacteriological
water quality.
 |
Annual Ranking System
2.10 The
Annual Ranking System reflects
the average water quality of a
beach for the whole bathing season.
The rank of a beach in each year
is determined by calculating the
geometric mean E. coli
level of all samples collected
at the beach during the bathing
season from March to October.
The four ranks correspond to the
respective swimming-associated
illness rates identified during
the epidemiological studies conducted
in late 1980s. Both "Good"
and "Fair" ranks meet
the WQO for bathing water. The
annual ranking system is summarised
in Table 2.2.
|
|
Rank
|
E.coli
count per 100mL*
|
Minor
illness rate **
(Cases per 1000
swimmers)
|
WQO
Complinace
|
|
Good
|
<=24
|
UD
|
Complied
|
|
Fair
|
25-180
|
<=10
|
|
Poor
|
181-610
|
11-15
|
Not
complied
|
|
Very
Poor
|
>610
|
>15
|
| Table
2.2 Annual
ranking system |
|
|
|
*
|
Geometric
mean E.coli count calculated based
on all data collected during the
bathing season. |
|
**
|
Skin
and gasrointestinal illness |
|
UN
|
Undetectable |
|
|
Weekly Grading System
2.11 The
weekly grading system is developed
to provide the latest information
on the beach water quality to the
public. The grade of a beach is calculated
on the basis of the geometric mean
E. coli level of the 5 most
recent sampling occasions. To further
safeguard the health of bathers, the
worst grade, i.e. Grade 4, is also
given to a beach when its last E.
coli count exceeds a high figure
of 1,600 per 100 mL irrespective of
the geometric mean. Therefore, a beach
grade reflects the short-term water
quality trend of the last few weeks
or recent deterioration of water quality.
The weekly grading system is summarised
in Table 2.3.
|
|
Grade
|
Beach
Water Quality
|
E.
coli count per
100mL*
|
Minor
illness rate**
(Cases per 1000
swimmers)
|
|
1
|
Good
|
<=24
|
UD
|
|
2
|
Fair
|
25-180
|
<=10
|
|
3
|
Poor
|
181-610
|
11-15
|
|
4
|
Very
Poor
|
>610
or
last reading >1,600
|
>15
|
| Table
2.3 Weekly
grading system |
|
|
|
*
|
Except
as indicated, the E. coli
level is the geometric mean of
the 5 most recent sampling occasions. |
|
**
|
Skin
and gastrointestinal illness |
|
UN
|
Undetectable |
|
|
Dissemination
of beach information
2.12 In
order to help the bathers to decide
on which beach they should go for
swimming, the beach grading is released
weekly to the public through press
release before the weekend during
the bathing season. Starting from
winter 2001, the grades of the opened
gazetted beaches are also released
weekly to the public during the winter
months. Therefore, the weekly press
release for the grading of beaches
will be issued all year round in 2002.
2.13 To
ensure the timely information on beach
water quality is available to the
public, the latest information on
beach grades is also disseminated
through a dedicated webpage for beach
water quality at EPD's website (http://www.info.gov.hk/epd/).
The webpage is updated as soon as
the latest beach grading is available.
Other information related to the beach
such as the location of the beach
and the availability of beach facilities
is also included in this webpage.
The information available in the webpage
is illustrated in Figure 2.3.
2.14 In
addition, a hotline (2511 6666) dedicated
for the beach grading has been set
up. This hotline will be updated at
the same time when the webpage is
updated to provide the latest grading
information. Bathers may check the
latest beach grading through this
hotline.
2.15 The
latest weekly grade will also be displayed
on the beach notice board by LCSD
at each of the opened gazetted beaches.
Bathers may also check this notice
board before swimming.
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Figure
2.3 Webpage
on beach water quality
|
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|