| Annual
Ranking System
The current
Beach Monitoring Programme has
been designed to assess the bacteriological water quality of bathing
beaches and the compliance with the WQO. The beach monitoring data
would also provide information on beach water quality trends for
the authority to decide on whether a beach should be opened or closed
for swimming. The monitoring of beach water quality is based on
the measurement of E. coli density which is
the microbiological parameter stipulated in the WQO and is also
an internationally acceptable indicator.
The establishment
of an annual ranking system facilitates the interpretation of long
term water quality changes at different beaches. The rank of a beach
is determined by calculating the annual geometric mean E.
coli density with all the data collected during the
bathing season from 1 March to 31 October.
Under the annual
ranking system, beaches are classified according to their annual
geometric mean E. coli densities in the beach
water. There are four categories for the annual ranking of beaches,
viz. "Good", "Fair", "Poor" and "Very
Poor". The water quality of beaches in the first two categories
i.e. "Good" and "Fair", meets the WQO for bathing
beaches. Beaches having annual geometric mean E. coli
densities greater than 610 per 100mL are ranked "Very Poor"
and the beach
management authority would consider closing these beaches for
the next bathing season.
| Annual
ranking system for beaches |
| Rank |
E.
coli count per 100mL* |
Minor
illness rate**
(Cases per 1000 swimmers) |
WQO
Compliance |
|
Good
Fair
|
<
24
25 - 180
|
undetectable
< 10
|
Complied
|
|
Poor
Very Poor
|
181 -
610
> 610
|
11 to
15
>15
|
Not complied |
* Geometric
mean E. coli count calculated based on all the data
collected during the bathing season.
** Gastrointestinal and skin complaints
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the rank and grade of a beach?]
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