| Beaches
and Beach Water Quality in Hong Kong
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| 5.2.1.26 |
A
total of 50 beaches (41 gazetted; 9 non-gazetted)
in Hong Kong are routinely monitored for
bathing water quality by EPD during the
bathing season (March to October inclusive).
Gazetted beaches are monitored 4-6 times
per month (non-gazetted, twice per month)
during the bathing season to provide weekly
up-to-date information on bathing water
quality (EPD 1998b). Water samples are principally
analysed for bacterial contamination (E.
coli) against a WQO which has been set
for E. coli at 180 per 100 mL.
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| 5.2.1.27 |
Data
on beach water quality are analysed in two
ways. During the bathing season a beach
grading system is used principally to provide
weekly information on water quality and
is based on the E. coli level (running geometric
mean) of the 5 most recent consecutive samples.
Annual beach ranking is undertaken to provide
longer term trend data and the analysis
is based on the geometric mean E. coli level
for the whole bathing season. For both systems
a four tier rank/grade is applied (1=Good;
2=Fair; 3=Poor; 4=Very Poor) depending upon
the E. coli count obtained. Summary data
for annual beach water rankings are shown
in Table 5.2a for the years since the present
ranking system was adopted in 1992.
| Table
5.2a Annual Rank of Beach Water Quality
1992-1998 |
|
Year |
Number of Beaches Ranked |
Number of Gazetted Beaches within Each
Ranking Category : Good |
Number of Gazetted Beaches within Each
Ranking Category : Fair |
Number of Gazetted Beaches within Each
Ranking Category : Poor |
Number of Gazetted Beaches within Each
Ranking Category : Very Poor |
| 1992 |
42 |
18 |
14 |
7 |
3 |
| 1993 |
42 |
17 |
12 |
10 |
3 |
| 1994 |
42 |
15 |
14 |
11 |
2 |
| 1995 |
43 |
16 |
10 |
13 |
4 |
| 1996 |
41 |
13 |
14 |
10 |
4 |
| 1997 |
41 |
10 |
16 |
12 |
3 |
| 1998 |
41 |
16 |
16 |
8 |
1 |
Source:
Data provided by EPD, January 1999 ((3)
in WSG/EM/Data Req.)
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| 5.2.1.28 |
AThe
data show that between 1992 and 1997, the
number of beaches with water quality ranked
'good' declined substantially, whilst the
number of beaches in the 'poor' category
increased slightly. The categories for 'fair'
and 'very poor' changed little over this
period and overall a declining trend in
beach water quality could be identified.
However this trend was reversed in 1998
when over 75% of Hong Kong's gazetted beaches
were ranked as 'good' or 'fair' and therefore
complied with the WQO.
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| 5.2.1.29 |
In
recent years, those gazetted beaches which
have been classified as 'poor' or 'very poor'
are located primarily in the Tuen Mun or Tsuen
Wan districts. This area is known to be affected
by point and non-point sources (ie unsewered
discharges) from industrialised areas and
villages along the Tai Lam coast. One exception
to this geographic trend is Rocky Bay Beach
on southern Hong Kong Island. Although the
commissioning of the Sewage Screening Plant
SSP at Shek O has coincided with a decrease
in E. coli concentrations at Rocky Bay Beach,
and this may be due to the collection and
routing of some of the polluting discharges
in the vicinity of the beach to the SSP, the
water quality at the beach is still rated
as 'poor'. The continued 'poor' rating may
be due to discharges from unsewered areas
along the coast or to polluted discharges
from storm drains in the vicinity of the beach
(ERM 1998f). |
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| 5.2.1.30 |
Hong
Kong's beaches are also subject to pollution
in the form of algal blooms (see Paragraph
5.2.1.15) and floating refuse. There has been
a steady increase in the amount of refuse
collected from gazetted beaches in the last
10 years (from 6,584 m3 in 1989 to 10,840
m3 in 1998). Whilst this trend may reflect
the increased effort devoted to refuse collection
since 1994, it also suggests that the source
of the marine refuse problem is continuing.
Further discussion of marine debris is provided
in Paragraph 4.3.3.7 - Marine Habitat and
Species Loss and discussion of littering and
other unauthorised waste disposal can be found
in Paragraph 3.2.2.10 (Land Use and Land Supply). |
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