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Beach
Water Quality Report 2002
Chapter Four
Beaches
in the Southern District
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| 4.1 |
The
twelve beaches in the Southern
District continued to meet
the WQO for bathing water
in 2002. Among these, eleven
were ranked 'Good' and one
was ranked 'Fair' in water
quality (Figure 4.1). The
'Good' water quality beaches
were mainly located at the
south of Hong Kong Island
where sewerage systems were
provided to the premises
and sewage was conveyed
to sewage treatment plants
for proper disposal (Figure
4.2). |
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| 4.2 |
These
'Good' water quality beaches were
also less susceptible to the effect
of heavy rain and had little fluctuation
in water quality (Figure 4.3).
In particular, South Bay, Stanley
Main and St. Stephen's had consistent
'Good' water quality in 2002.
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| 4.3 |
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The
hinterland of Deep Water
Bay is now completely sewered
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In August 2001,
wastewater from the beach facilities
of Deep Water Bay was diverted
to a public sewer. Since then,
the water quality of Deep Water
Bay has slightly improved with
the annual geometric mean E.
coli count improved to 10
per 100mL in 2002. With this
diversion, the hinterland of
Deep Water Bay is now completely
sewered.
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| 4.4 |
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With
the improvement of water
quality at Tathong Channel,
the rank of Shek O Beach
has also improved to 'Good'
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The water quality
of the three beaches on the
east of the Hong Kong Island,
namely Shek O, Rocky Bay and
Big Wave Bay has significantly
improved as compared with 2001
(Figure 4.4). The water quality
of Shek O and Big Wave Bay has
improved from 'Fair' to 'Good'.
Although the annual rank of
Rocky Bay remained at 'Fair',
the annual geometric mean E.
coli count was reduced from
118 per 100mL in 2001 to 43
per 100mL in 2002.
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| 4.5 |
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| Sewage
from Chai Wan Preliminary
Treatment Works has been
diverted to the tunnel network
of HATS |
The improvement was mainly due
to the commissioning of Stage
I of HATS at the end of 2001.
The Stage I of HATS comprises
a deep tunnel network for collection
and transfer of sewage to a centralized
sewage treatment plant at Stonecutters
Island for treatment and a submarine
outfall for disposal of the effluent
to the western approaches of the
Victoria Harbour. Sewage arising
from Chai Wan and Tseung Kwan
O, which was previously discharged
to the Tathong Channel via submarine
outfalls, had been diverted to
the tunnel network (Figure 4.5).
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| 4.6 |
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The
unsewered hinterland of
Big Wave Bay is still a
potential pollution source
for the beach |
Although pollution of the marine
water at Tathong Channel has been
mostly removed, the water quality
of Big Wave Bay, Shek O and Rocky
Bay is still susceptible to the
effect of heavy rain. The hinterland
of Big Wave Bay is unsewered,
while that of Shek O and Rocky
Bay is only served by a combined
drainage system and is partially
sewered. Some of the squatter
houses are still served by septic
tank and soakaway pit systems.
During heavy rain, pollutants
may be flushed out from the surface
channels as well as the septic
tank and soakaway pit systems.
This resulted in wider fluctuation
in water quality at these beaches,
in particular Big Wave Bay, during
the bathing season (Figure 4.3).
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