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Routine
monitoring of marine sediments is conducted monthly by
the Environmental Protection Department (EPD) at 52 stations
in open water sites throughout Hong Kong. A number of
parameters are measured including physico-chemical determinands
(eg temperature, salinity, dissolved oxygen, pH), nutrients
(eg nitrite nitrogen, nitrate nitrogen, ammoniacal nitrogen,
total phosphorous), metals (eg arsenic, aluminium, cadmium,
chromium, copper, iron, mercury, manganese, nickel, lead,
zinc) and some organic contaminants (ie PCBs and PAHs).
Data on other organic contaminants such as pesticides
(eg DDT) and tributyltin are, however, limited. Data on
organic contaminant concentrations in sediments, and to
a more limited extent in tissue, are also provided by
a variety of datasets compiled under monitoring programmes
for contaminated mud and sludge disposal, sewage outfalls
and areas of special water quality focus (eg the proposed
SSDS deep ocean outfall). Basic information on location
and duration of these monitoring programmes is given in
Table 1.5a. In addition to these large scale monitoring
programmes, periodic measurements of organics contaminants
in the marine environment have been collected under various
sediment characterisation programmes for reclamation projects.
These datasets are not likely to be particularly useful,
however, due to differences in methodology, the snap-shot
(ie one-time) nature of the sampling and the fact that
these sediments are now likely removed from the location
at which they were sampled.
| Table
1.5a Summary of Marine Monitoring Programmes for
Organic Contaminants |
| Programme |
Location |
Duration |
Remarks |
| East
Sha Chau Contaminated Mud Pits Monitoring |
NW
Waters between Lantau and Tuen Mun |
Nov
1992 - ongoing |
Programme
has expanded in scope over time |
| Waglan
Sludge Disposal Site |
SE
Waters off Waglan Island |
Summer
1987 - Summer 1997 |
Sludge
disposal ceased in April 1996 |
| SSDS
Stage I Outfall Verification Study |
Western
Harbour off Stonecutter's Island |
Summer
1996 -ongoing |
Programme
emphasis on organics is diminishing |
| SSDS
EIA |
Southern
Waters predominantly South of Lamma Island |
Aug-Sept
1996 |
Single
survey to establish a wet season baseline |
| Urmstone
Road |
NW
Waters near Lung Kwu Chau |
May
1995 - Dec 1996 |
Limtied
organics analysis |
| Siu
Ho Wan |
NW
Waters off the northeast coast of Lantau Island |
Feb
1995 - Sep 1996 |
Baseline
compliation complete |
| Pillar
Point |
NW
Waters offshore of Tuen Mun |
Aug
1997 - ongoing |
Baseline
compliation ongoing |
Despite the existence of a variety of datasets including
measurements of organic contaminants in sediment and
tissue, a comprehensive database comparable to that
held by EPD on metals is not available for organics.
In addition, the independent nature of the studies cited
above has resulted in the use of different methodologies
for sampling and analysis which complicates the use
of these data as a coherent baseline dataset. Nevertheless,
this study has also made reference to other published
sources of information relating to toxic organic contamination
in Hong Kong's marine environment. It should be noted,
however, that these references are for comparative purposes
only and that analytical techniques used differ between
studies.
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