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Our
Own Operations
Reducing
Pollution and Hazards
We
will avoid, reduce or control environmental pollution arising
from our day-to-day working practices. We will require our
contractors to adopt and implement sound environmental management
systems and pollution control measures
We
will provide leadership by complying with not only the letter,
but the spirit of all applicable environmental legislation,
standards and regulations, as well as our internal guidelines
and procedures. We will endeavour to surpass the applicable
environmental legislation, standards and regulations, whenever
possible
"
Image
of The Island West Refuse Transfer Station is housed in a
cavern
Image of Waste vehicles are thoroughly washed before leaving
the refuse transfer station
Waste
Facilities
We ensure
the environmental performance of the 22 waste facilities run
by our contractors through both contractual management and
statutory control. The contractors are required to comply
with all relevant environmental ordinances, regulations and
emission conditions. All monitoring of air, noise and waste
water emissions from these facilities is supervised closely
by EPD staff on site. Since 1989, we have been implementing
non-compliance payment deduction schemes in our waste facility
contracts as one of the tools to promote good environmental
performance of our contractors.
Compliance
Rate
In 1999,
no environmental prosecution was taken against any of our
waste management contractors. The contractors' overall compliance
with the contractual environmental performance requirements
was 99.9%. Nevertheless, each non-compliance was thoroughly
investigated and remedial action instigated.
For example,
in February 1999, stack gas monitoring at the Chemical Waste
Treatment Centre (CWTC) at Tsing Yi indicated that the level
of dioxin emission exceeded the contract limit of 0.1 ng I-TEQ/Nm3
(which is the most stringent limit by international standards),
even though the ambient level remained low. The exceedence
was found to be caused by the malfunction of an activated
carbon injection system. The problem was quickly rectified
and no further dioxin exceedence occurred during the year.
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Dioxins
are the common name for a family of chemicals with similar
properties and toxicity. The most toxic one is 2,3,7,8-tetrachlorodibenzo-p-dioxin,
or TCDD. They are the unintended by-products of industrial
processes that involve chlorine or that burn chlorine
containing organic matter.
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Complaints
In 1999,
six of the 18 complaints against the waste facilities required
follow-up action by our contractors. Complaints included bad
odours, noise, dust, illegal dumping and speeding. All complaints
were dealt with promptly to the satisfaction of the complainants.
Pollution
Control Measures
- Landfills
All new landfills have gas extraction systems installed
from the start, and old landfills are being retrofitted.
The boundaries of the landfills are monitored to ensure
the landfill gas does not escape. In 1999, an average 640,000
m3 of landfill gas was collected daily, 37% of which is
used to meet nearly all on-site electricity consumption.
To date, electricity generators with a total capacity of
7.7 MW have been installed at seven landfills. At the Shuen
Wan Landfill, the gas is used as a process gas to produce
towngas at the nearby Tai Po plant of the Hong Kong and
China Gas Co. Ltd. A construction and demolition (C&D) waste
recycling plant has been operating on the Southeast New
Territories (SENT) landfill since 1995, sorting and recycling
any C&D waste delivered for beneficial reuse (such as in
reclamation) and to reduce the amount of waste taking up
landfill space. At present the plant is recycling about
38,000 tonnes of C&D waste monthly, representing 15% of
the total waste intake at the landfill.
- Refuse
Transfer Stations
At the RTSs, which are mostly located in built-up areas,
ventilation systems and odour scrubbers are installed to
remove offensive odours and dust from the exhaust air. The
Island West RTS is located within a man-made cavern under
Mount Davis which not only reduces its visual impact, but
also takes up less valuable land space.
- Chemical
Waste Treatment Centre
Stack gas from the incineration system is scrubbed and
a spray dry absorber, activated carbon injection and fabric
filter baghouses are used to remove pollutants prior to
release into the atmosphere. The gas is monitored continuously
to ensure complete combustion and removal of air pollutants.
In the event of any problem, waste feed to the incinerator
is stopped automatically. The ambient air around the CWTC
is monitored twice yearly and measurement of dioxins is
carried out monthly. So far, all ambient air measurements
are within the Hong Kong Air Quality Objectives. All process
residues, including incineration ash, are chemically treated
and confirmed to be stable by analysis before being sent
to the SENT landfill for final disposal.
Figures
of New landfills are equipped with liners and gas extraction
system
Image of Landfill gas recovered from an old landfill is utilised
in the nearby towngas plant
Image of Construction and demolition materials from the waste
delivered to the SENT landfill are sorted out for beneficial
use
Chart of The Chemical Oxygen
Demand (COD) level of the effluent from Southeast NT Landfill
in 1999
Laboratories
Our laboratories
(air, chemical, water sciences and microbiological) are operated
in a manner to minimise the impact on the environment. In
1999, routine monitoring of the effluent discharge from our
laboratories indicated that, with the exception of Chemical
Oxygen Demand which achieved 99% compliance, all other monitoring
parameters achieved 100% compliance. Annual monitoring of
the emission of acid fumes from fume cupboards also indicated
full compliance with preset limits.
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Measures
adopted to prevent pollution:
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All necessary licences and permits under the law (e.g.
Water Pollution Control Ordinance (WPCO), Waste Disposal
Ordinance (WDO), etc). are obtained and the conditions
stipulated are strictly adhered to
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Emissions from fume cupboards and safety cabinets,
including those for asbestos, are scrubbed or filtered
as required to remove the pollutants before release
into the atmosphere
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Most of the laboratory sinks are fitted with buffer
tanks to prevent the accidential discharge of unsuitable
substances into the sewers. Buffer tanks will be installed
for the remaining seven sinks by 2001. The sink that
is used for handling asbestos is also fitted with
a filter to remove the asbestos from the waste water
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Emissions from the fume cupboards and discharges from
sinks are regularly monitored to ensure compliance
with the required standards
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Chemical waste is properly disposed of by the CWTC
contractor and biological waste is disinfected and
disposed of in accordance with World Health Organisation
guidelines
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Emergency spill kits are provided in all the laboratories
and our staff are trained to deal with accidental
spills
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Environmental audits of the laboratories are carried
out regularly by the laboratory staff concerned with
supplemental external audits by the MSU
Image
of Emissions from the fume cupboard are monitored regularly
Image of Chemical waste is stored properly before removal
for disposal by licensed contractor
Image of Biohazardous waste is sterilised before disposal
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Field
Work
To minimise
the effect on the environment in sewerage investigation work,
only non-toxic dye is used to trace the source of pollution.
Any chemicals used in field measurements and analysis are
returned to the laboratories for proper disposal. Safety guidelines
are issued to all field staff who are trained in the use of
hazardous materials.
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