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Minimising
Impacts of Our Operations
Waste
Facilities
THE EPD
OVERSEES 29 waste facilities and we require our contractors
to operate them to a high environmental standard, through
both contractual requirements and statutory controls. The
contractors must comply with all applicable environmental
ordinances, regulations and emission conditions. Air, noise
and wastewater emissions from these facilities must be monitored
and this is supervised closely by EPD staff on site. Since
1989, we have included a provision in waste facilities contracts
to deduct payment for non-compliance with environmental controls.
In 1999
tenderers for the new Northwest New Territories Refuse Transfer
Station were required to develop and obtain ISO14001 EMS certification
within 24 months of the contract being awarded. All new waste
facilities contracts must have similar ISO certification.
Compliance
Rate
In 2000,
no environmental prosecution was taken against any of our
waste management contractors. The contractors' overall compliance
with the contractual environmental performance requirements
remained at 99.9% as for last year. Nevertheless, each non-compliance
was thoroughly investigated and remedial action instigated.
For example,
the contractual limit for Total Suspended Particulates (TSP)
was exceeded three times at the early stages of construction
of one of the refuse transfer stations. The contractor was
advised to revise its work plan to limit the extent of excavation
and to improve site cleanliness. Generation of air-borne dust
was reduced and the problem was remediated.
Complaints
In 2000
there were five complaints received against our waste facilities.
Complaints included gas emissions, fly nuisance, river bank
erosion and indiscriminate waste disposal. All complaints
were dealt with promptly.
Chart
of Dioxin levels in stack gas of Chemical Waste Treatment
Centre in 2000
Image
of Landfill gas is used to generate electricity
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 landfill gas does not
escape. In 2000, an average 802,000 m3 of landfill gas was
collected daily, 44% of which is used to meet nearly all on-site
energy consumption. To date, electricity generators with a
total capacity of 7.4 MW have been installed at six landfills.
A construction
and demolition (C&D) waste recycling plant has been operating
on the Southeast New Territories (SENT) landfill since 1995,
to sort and recycle any C&D waste delivered for beneficial
reuse and to reduce the amount of waste taking up landfill
space. At present the plant is recycling about 35,000 tonnes
of C&D waste monthly, representing 14% of the total waste
intake at the landfill.
Refuse
Transfer Stations
Refuse
Transfer Stations (RTSs) help to reduce the environmental
impact of transporting waste to landfills. Small refuse collection
vehicles (RCV) deliver waste to the RTSs where it is transferred
into bulk waste containers that are taken to landfills either
by land or by sea. Each container can accommodate the equivalent
of three to five RCV-loads. In 2000 some 1,000 RCV trips to
landfills were eliminated each day. Bulk waste transfer, by
sea in particular, has significantly reduced the traffic,
noise and air emission problems that might otherwise be caused
by directly hauling waste to landfills. An eighth RTS will
be commissioned in the North West New Territories in late
2001.
The seven
RTSs 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 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 normal range. 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.
Environmentally
friendly practices are encouraged by allowing the contractor
to keep revenue generated from the sale of materials recovered
from waste. The oil recovered from the oil/water waste of
ocean-going vessels is sent to a local cement plant for use
as a fuel, instead of being incinerated. The copper oxide
recovered from waste etchant used by the electronics industry
is sent to a smelter in the United States to recover the copper.
In 2000, 7,840 tonnes of oil and 374 tonnes of copper oxide
were recovered by the Centre.
Laboratories
Our laboratories
(air, chemical, water sciences and microbiological) are operated
in a manner that minimises the impact on the environment and
in compliance with the legal requirements and statutory licence
conditions. In 2000, routine monitoring of the effluent discharge
from our laboratories indicated 100% compliance. Annual monitoring
of the emission of acid fumes from fume cupboards also indicated
full compliance with preset limits.
Field
Work
To minimise
the environmental impacts during our 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 handling
of hazardous materials.
Image
of Emissions from the stack of CWTC are closely monitored
Image
of Emergency spill kit used in the laboratories
Emergency
Response at EPD Facilities
The EPD
has internal emergency response plans for our own operations,
in particular our waste facilities and laboratories. For landfills,
the plans cover predictable events such as the unavailability
of certain landfills or refuse transfer stations due to power
failure, as well as road blockages arising from traffic accidents,
congestion, chemical waste spills, etc.
For the
CWTC, two emergency drills were carried out in 2000. The first
drill assumed a spillage of chemical waste on site, and the
second drill assumed a spillage of MARPOL waste during its
transfer from an ocean-going vessel to a collection barge.
For our laboratories, no incidents were reported in 2000.
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Measures
adopted to prevent pollution from the laboratories:
Legal
measures:
All
necessary licences and permits under the law (e.g. Water
Pollution Control Ordinance (WPCO), Waste Disposal Ordinance
(WDO), etc.) are obtained and the stipulated conditions
are strictly adhered to
Air
pollution:
Emissions
from fume cupboards and safety cabinets, including those
for asbestos, are scrubbed or filtered as required to
remove pollutants before release into the atmosphere
Water
pollution:
Most
laboratory sinks are fitted with buffer tanks to prevent
the accidental discharge of unsuitable substances into
the sewers. Buffer tanks will be installed in the remaining
two sinks by 2001. A sink used for handling asbestos
is also fitted with a filter to remove the asbestos
from the waste water
Monitoring:
Emissions
from fume cupboards and discharges from sinks are monitored
regularly to ensure compliance with the required standards
Hazardous
waste:
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.
A licensed collector is engaged to deliver asbestos
samples from the air laboratory to the SENT landfill
for disposal
Emergencies:
Emergency
spill kits are provided in all the laboratories and
our staff are trained to deal with accidental spills.
The general procedures for handling chemical spillage/leakage
are documented in the laboratory environmental and safety
manuals
Audits:
Environmental
audits of the laboratories are carried out regularly
by laboratory staff and supplemented with external audits
by the EPD's Management Support Unit
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