DATE OF ISSUE: 22/11/2000
NEW FEATURES IN SINGAPORE'S LARGEST AND NEWEST INCINERATION PLANT
Tuas South Incineration Plant (TSIP) is Singapore's fourth and largest refuse incineration plant. With new state-of-the art features to boost efficiency and throughput, TSIP, together with the other three incineration plants and the offshore Semakau Landfill will meet the refuse disposal needs of Singapore.
Built at a cost of $S900 million, the Ministry of the Enviroment's (ENV) fourth waste-to-energy plant can incinerate 3,000 tonnes of refuse every day through its six incinerators, nearly twice the amount of refuse currently being incinerated at Tuas Incineration Plant.
Together the four plants - Ulu Pandan Refuse Incineration Plant, Tuas Incineration Plant, Senoko Incineration Plant and TSIP will have the capacity to incinerate 8,200 tonnes of refuse daily.
TSIP is the first incineration plant in Southeast Asia to use SiC tiles as refractory materials in the furnace. Refractory materials are required to protect the surfaces of the boiler wall tubes and furnace castings from the high temperature flame, highly abrasive flyash and highly corrosive flue gases which are generated as a result of the intense combustion in the furnace. It is critical to operational efficiency for these refractory materials to be able to withstand the harsh operating environment for long periods without excessive wear and corrosion. Otherwise, there will be a need to have frequent shutdowns for maintenance. The high-quality SiC tiles are expected to have a longer life span and can easily be replaced owing to an easy-to-install hooking system.
Operational efficiency of the plant will also be increased and manpower reduced with the use of an advance Digital Control System which allows more pieces of equipment in the incineration process to be operated, monitored and controlled simultaneously. Instead of deploying one operator to operate an incinerator, TSIP requires only one operator to operate up to three incinerators. The automation also frees operators from routine tasks to concentrate on optimizing the plant's throughput.
The plant's four high capacity rotary bulky waste crushers will help improve efficiency as well. Refuse comes to the plant in various shapes and sizes. As the incinerators are designed for mass combustion of municipal waste, there are size limitations to the type of refuse that can be fed into the furnace. These crushers will help overcome these constraints. They are integrated in the refuse reception hall, allowing refuse trucks to discharge their loads directly into the crushers.
TSIP is a "green" plant, helping to conserve our portable water resources by using industrial water pre-treated by its own water reclamation plant for use in the boilers. The reverse osmosis water reclamation plant, which makes use of the latest membrane technology, will save the plant approximately 194,000m3 of potable water annually. The plant will also not consume any of Singapore's present electricity resources. Rather it will generate 80 MW of electricity, 80% of which will be made available for the public to use. Together the four plants supply about 2 % of Singapore's overall electricity consumption. Like all the other incineration plants, ferrous metals are recovered for recycling. The amount of wastewater discharged from TSIP is also minimized by way of a design which allows wastewater drainage from the refuse bunker to be collected and pumped back into the bunker for dust suppression and eventual destruction in the furnace.
Incineration reduces the volume of waste substantially, by as much as 90%. As land is limited in Singapore, ENV has adopted the policy of incinerating all incinerable waste in order to conserve land. Incineration infrastructure however does not come cheap. ENV has spent $1.83 billion building these four incineration plants and $610 million for the offshore Semakau Landfill.
Our severe land constraints and the high cost of building and maintaining refuse disposal facilities means that we cannot afford to continue subsidising waste disposal. By subsidising refuse generation, we are, in effect discouraging recycling and waste minimisation. This is because companies will find it much cheaper to simply send their waste for disposal instead of making the necessary efforts to minimise waste. Artificially low waste disposal charges will also make recycling plants non-viable, thereby discouraging investors from setting up such operations.
Thus, as announced earlier in Jan 99 and in April 2000, refuse disposal fees will be increased progressively to encourage waste minimisation and to partially offset the high costs of building refuse disposal infrastructure. Disposal fees will therefore continue to be increased according to the schedule announced: $10 a year till it reaches $87 per tonne in 2002. So far two increases have been implemented. The next increase will be effected early next year.
As the cost of infrastructure increases, the cost of waste disposal in Singapore can only escalate over time. The increases in refuse disposal fees and waste minimisation is thus necessary to ensure that our waste disposal capacity is used at a more sustainable rate. Privatisation of the waste disposal industry will allow competition to keep such increases down.
Ministry of the Environment Singapore
The Incineration Process at Tuas Incineration Plant
ADDITIONAL NOTES
Volume of waste produced in Singapore 1970-2000:
§ 1970 – 1,278 tonnes per day
§ 1980 – 2,573 tonnes per day
§ 1990 – 5,695 tonnes per day
§ 2000 – 7,651 tonnes per day
§ 2002 – 7,192 tonnes per day (the govt. believes the lower figure for 2002 demonstrates that waste minimisation and recycling programmes are becoming successful), 92% of all solid waste was incinerated in 2002; the remainder was taken to Pulau Semakau landfill site, 54.7% of this solid waste was generated from residential premises, food centres and markets. Commercial and industrial premises accounted for the remaining 45.3%.
The average amount of domestic refuse generated per person per day in 2002 was 0.94 kilogram’s.
4 incineration plants (Ulu Pandan 1979; Tuas 1986; Senoko 1992; Tuas South 2000)
The I.P.s generate 1,300 Kw of electricity per year (i.e. about 2-3% of the total power used in Singapore)
The I.P.s recover about 25,000 tonnes of ferrous scrap metal per year
Tuas I.P. employs 141 staff (mostly engineers) and operates all year round
Tuas I.P. incinerates 1,700 tonnes of refuse per day
Ash and non-incinerable waste (e.g. concrete rubble from construction sites) are transported to Pulau Semakau/Pulau Sakit (about 25 kms from the mainland)
When the Pulau Semakau landfill is full up, it will cover an area of 350 hectares and may be turned into a golf course or a marina with holiday chalets our private refuse collection companies collect waste from houses, condominiums and commercial premises. They also collect recyclable materials from households.
Refuse Reception Hall
Central Control Room
Refuse Combustion in the Furnace
Refuse Bunker
EMBASSY OF THE REPUBLIC OF INDONESIA
Tuas I.P. incinerates 1,700 tonnes of refuse per day
Ash and non-incinerable waste (e.g. concrete rubble from construction sites) are transported to Pulau Semakau/Pulau Sakit (about 25 kms from the mainland)
When the Pulau Semakau landfill is full up, it will cover an area of 350 hectares and may be turned into a golf course or a marina with holiday chalets our private refuse collection companies collect waste from houses, condominiums and commercial premises. They also collect recyclable materials from households.
Refuse Reception Hall
Central Control Room
Refuse Combustion in the Furnace
Refuse Bunker
EMBASSY OF THE REPUBLIC OF INDONESIA
55 Parkdale AvenueOttawa, ON K1Y 1E5
JAKARTA COPIES NEIGHBORS' PLANSThe Jakarta Post
City Secretary Ritola Tasmaya said that Jakarta has been copying Singapore in using incinerators to overcome its garbage disposal problem.
The city plans to buy four incinerators by 2007, each of them with the capacity to process up to 2,000 tons of waste.
According to Singapore's Ministry of Environment and Water Resources website, the state operates four incinerators with a total capacity of 8,200 tons of waste per day. The capacity is higher than Singapore's daily waste of 5,800 tons. The four incinerators handle 90 percent of the country's waste.
The remaining 10 percent is processed using the sanitary landfill system.
Singapore's Tuas South Incineration Plant (TSIP) -- which will be copied by Jakarta -- is the largest incineration plant in the country.
The three others are the Ulu Pandan Refuse Incineration Plant, the Tuas Incineration Plant and the Senoko Incineration Plant.
TSIP, which was constructed in 2000 and cost S$900 million (US$542. 17 million), can process around 3,000 tons of daily waste using its six machines.
The plant is provided with four high capacity rotary bulky waste crushers to improve efficiency because garbage comes to the plant in various shapes and sizes.
The plant produces 80 megawatts of electricity, 80 percent of which will be made available for the public to use, while another 20 percent is used for the plant.
The four incineration plants produce 2 percent of the overall electricity used by Singapore.
High-capacity incinerators are currently also in service in several cities in other industrialized countries like Australia, Hong Kong, Japan, South Korea and Taiwan.
Bangkok has also installed conventional incineration plants at two of its landfill sites but one of them was shut down recently due to opposition from the public.
Jakarta purchased 15 small-scale incinerators in 2000 and 2001, each priced at Rp 25 million (US$2,762).
However, the incinerators, proved to be ineffective as the highest temperature reached was only 900 degrees Celsius, while they produced a lot of smoke and consumed a large amount of fuel.
Tuas Incineration Plant is under the administration of the Engineering Services Department, Ministry of Environment. The plant construction was completed as scheduled in October 1986 and the total cost is approximately $200 million.
It is capable of incinerating 2000 tonnes of refuse each day. This brings the total tonnage of refuse incinerated in Singapore from an average of 1300 tonnes to 3300 tonnes per day. This figure is 65% of the total amount of refuse generated daily in the nation.
To make the best use of refuse, the heat released from combustion process is used to generate electricity. The amount of power output not only supports the operational needs of the plant itself, but the excessive power is also sold to the local electrical power company which then redistribute the power for commercial, industrial and residential uses.
Moreover, the ferrous scrap is extracted from the ash and then sold to the material recycle factories in order not to waste the resources and to strengthen the finance of the incineration plant.
The following lists the design data and the major equipment of the Tuas Incineration Plant :
Plant Design Data :
Plant Capacity : 2000 tonnes per day Number of Incinerator Units : 5 Average Calorific Value of Refuse : 6000 kJ/kg Steam Generated per boiler : 42 tonnes/hr Live Steam Pressure : 35 bar Live Steam Temperature : 375 degree Celsius Power Generation Capacity : 30 MW Generator Voltage : 6.6 kV
Main Plant Equipment :
Refuse Handling : 3 weighbridges of 40 tonnes capacity each 23 refuse discharge bays 3 refuse cranes using rope-operated multi-polyp grab of 8m3 capacity each 1 bulky waste rotary shear of 20t/hr capacity 1 bulky waste cutter shear of 20t/hr capacity
Refuse Incineration & Steam Generation : 5 Martin stoker furnace units with integral boilers
Flue Gas Handling : 1 three-zone electrostatic precipitator to each boiler unit with a dust separation efficiency of 99.5% 1 reactor for flue gas conditioning to each unit 1 concrete chimney, 150m high, with fire-brick inner-lining.
Ash Handling Plant : 2 pusher-type ash extractors to each unit
Scrap Metal Recovery Plant : 2 magnetic separators to each unit
Power Generation : 2 condensing turbines 2 generators of 23 MW rated capacity each
Steam Condensation : 2 air condensers with 8 fans each
Cooling System : Closed loop cooling water
To be a little bit more technical, here comes the detailed descriptions of the refuse handling steps taken in the actual running of the Tuas Incineration Plant :
Refuse container trailers and refuse collection vehicles are first weighed at the weighbridges before they are permitted to discharge the refuse into the bunker through one of the 23 refuse discharge bays. Refuse in the bunker is then fed into the incinerator furnaces by means of grab-cranes.
Refuse combustion is an exothermic process and it can be sustained without the need for auxiliary fuel. Before refuse can be fed into the furnace, the temperature of the furnace must be raised using industrial diesel burners. The normal operating temperature in the furnace is about 1000 degrees Celsius.
Each incinerator furnace has 4 incineration grates which spread and transfer the burning refuse slowly through the furnace. Air drawn from the refuse bunker is preheated by superheated steam and introduced into the furnace through the underside of the incineration grates.
The flue gas produced in the combustion process is used to generate steam. Superheated steam from the boiler is expanded through two condensing turbines, each of which drives a generator to produce electricity. Part of the electricity generated is used to operate the Plant and the surplus is sold to the Public Utilities Board.
The incinerator and turbo generator units together with their auxiliary equipment are operated and monitored via CRTs from a central control room. Illuminated mimic diagrams show the status of essential equipment and closed circuit TV monitors the combustion status of each incinerator unit. Combustion conditions in the furnace are controlled automatically by a digital control system which regulates the air distribution in the furnace and adjusts the feeding rate of refuse according to its heating value.
The ash residue from the furnace is transported to the ash pit via vibrating conveyors. Ferrous scrap metal is picked up from the ash by overhead electromagnetic separators and sold as scrap.
The flue gas leaving the boiler flows through an electrostatic precipitator which is designed to remove up to 99.5% of the dust content in the flue gas. The clean flue gas is emitted through a 150m tall chimney.
The Need for Waste Minimisation
Waste
Waste is defined as something that is rejected because it is deemed to be worthless or unneeded.
Sources of Waste
Waste generated in Singapore is broadly classified into two categories. They are:
(a) Domestic and Trade Waste- It is collected from residential premises, markets, food retail outlets, schools and trade premises.
(b) Commercial and Industrial Waste- It is collected from commercial and industrial premises, construction sites and shipyards.
Waste Disposal
In Singapore, about 90% of the waste is incinerated and the remaining non-incinerable waste is land filled. Prior to 1979, all waste was disposed of at landfills. To reduce the over-reliance on landfills and the fact that most of our waste is combustible and suitable for incineration, our first incineration plant was built in 1979 at Ulu Pandan.
At present, we have four incineration plants in Singapore. They are located at Ulu Pandan, Senoko, Tuas and Tuas South. The Tuas South Incineration Plant is one of the largest in the world.
Although incineration can reduce the volume of incinerable waste, we still need to landfill the non-incinerable waste and incineration ash which is the residue of the incineration process. Our former landfill sites had reached their design capacities. They were the Tampines Dumping Ground, Choa Chu Kang Dumping Ground, Kok Sek Lin Dumping Ground, Lim Chu Kang Dumping as well as the Lorong Halus Dumping Ground which was closed on 1 Apr 1999. Now, Pulau Semakau, the first offshore landfill, is the only landfill in Singapore. It started its operation on 1 Apr 1999. Everyday, we have to barge our non-incinerable waste and incineration ash toPulau Semakau via the Tuas Marine Transfer Station.
Problems Faced in Waste Disposal
Although we can reduce the volume of incinerable waste significantly by incineration, it is not a sustainable solution to manage waste and the environment for the following reasons:
Escalation of waste output
Land-scare Singapore
Costly waste disposal facilities
Save the environment
Escalation of waste output
Over the last 30 - 40 years, Singapore has transformed herself to an urbanised, industrialised and affluent country. This has led to a rising trend in our waste output. Our waste output has been escalating rapidly. In 1970, a total of 0.46 million tonnes of waste was disposed, whilst in 2005, a total of 2.55 million tonnes of waste was disposed. There is a 2.09 million tonnes increase in the amount of waste over a 35-year span. This growth in solid waste generation places considerable demands on waste management, disposal facilities and the environment.
Land-scarce Singapore
Singapore is well known for its clean and green city. However, our main land is only 682.7 sq km in area. Singapore is just a tiny state on the map and lacks land resources. Land is required for constructing factories, warehouses, schools, houses and recreational amenities etc. It is extremely difficult to find land in land-scarce Singapore to construct incineration plants and landfills. We have therefore resorted to build the first offshore Pulau Semakau landfill. The lifespan of Pulau Semakau is expected to last 30 years till 2030. If the rising trend of waste generation is not curtailed, the lifespan might be shorter than 30 years. Therefore there is a need to prolong the lifespan as long as possible.
Costly waste disposal facilities
It is expensive to construct, operate and maintain incineration plants and landfill. Way back in 1979, it cost only $130 million to construct an incineration plant while the fourth plant at Tuas South cost about $900 million. Moreover, some $610 million was also spent to construct the landfill at Pulau Semakau.
Table 1: High Construction Costs of Incineration Plants
Location of Incineration plant
Year, Construction Cost, Capacity (Tonnes/Day)
Ulu Pandan
1979, $130 million , 1100
Tuas
1986, $200 million , 1700
Senoko
1992, $560 million , 2400
Tuas South
2000, $900 million , 3000
Save the environment
Wasteful consumption patterns also exploit and diminish the natural resources. The waste also poses harmful effects to the environment, polluting the air and land. In order to save the living environment and conserve the natural resources, there is an obligation for the community to minimise waste output and to recycle as much waste as possible. For instance, recycling of paper reduces air pollution by 74% and water pollution by 35%. Each ton of paper recycled could also save 17 small trees.
Moreover, the ferrous scrap is extracted from the ash and then sold to the material recycle factories in order not to waste the resources and to strengthen the finance of the incineration plant.
History of Semakau Landfill
In 1999, when the last remaining landfill on Singapore’s mainland was exhausted, the Semakau Landfill was created by enclosing Pulau Semakau and a small adjacent island (Pulau Sakeng) with a rock bund. All our waste now ends up at Semakau, i.e., ash from the incineration plants and all non - incinerable waste.
During the construction of the landfill, effort was made to protect the marine ecosystem, especially mangroves and corals. 13 hectares of mangrove were replanted to replace those removed during construction of the bund. Wildlife continues to thrive on Pulau Semakau, and the air and water quality remains good.
Semakau opened!
On 16 Jul 05, Pulau Semakau was opened for nature-related recreational activities. Members of the public can now visit the island for bird watching, sports fishing and intertidal walks. Marine life of Pulau Semakau
The original Pulau Semakau which was not affected by the landfill construction has an enormous inter tidal area which is rich in amazing wildlife. The natural mangroves there shelter a wide variety of plants and animals, many no longer seen on the mainland or other islands. There is a vast sea grass lagoon, possibly the largest in Singapore. The coral reefs that line the edge of the island also thrive with marine life. Here's some posters of Semakau's inter tidal shores and more about a survey of Semakau's mangroves in 2005.Getting there
Currently, you can only visit Pulau Semakau by joining activities conducted by designated interest groups.
JAKARTA COPIES NEIGHBORS' PLANSThe Jakarta Post
City Secretary Ritola Tasmaya said that Jakarta has been copying Singapore in using incinerators to overcome its garbage disposal problem.
The city plans to buy four incinerators by 2007, each of them with the capacity to process up to 2,000 tons of waste.
According to Singapore's Ministry of Environment and Water Resources website, the state operates four incinerators with a total capacity of 8,200 tons of waste per day. The capacity is higher than Singapore's daily waste of 5,800 tons. The four incinerators handle 90 percent of the country's waste.
The remaining 10 percent is processed using the sanitary landfill system.
Singapore's Tuas South Incineration Plant (TSIP) -- which will be copied by Jakarta -- is the largest incineration plant in the country.
The three others are the Ulu Pandan Refuse Incineration Plant, the Tuas Incineration Plant and the Senoko Incineration Plant.
TSIP, which was constructed in 2000 and cost S$900 million (US$542. 17 million), can process around 3,000 tons of daily waste using its six machines.
The plant is provided with four high capacity rotary bulky waste crushers to improve efficiency because garbage comes to the plant in various shapes and sizes.
The plant produces 80 megawatts of electricity, 80 percent of which will be made available for the public to use, while another 20 percent is used for the plant.
The four incineration plants produce 2 percent of the overall electricity used by Singapore.
High-capacity incinerators are currently also in service in several cities in other industrialized countries like Australia, Hong Kong, Japan, South Korea and Taiwan.
Bangkok has also installed conventional incineration plants at two of its landfill sites but one of them was shut down recently due to opposition from the public.
Jakarta purchased 15 small-scale incinerators in 2000 and 2001, each priced at Rp 25 million (US$2,762).
However, the incinerators, proved to be ineffective as the highest temperature reached was only 900 degrees Celsius, while they produced a lot of smoke and consumed a large amount of fuel.
Tuas Incineration Plant is under the administration of the Engineering Services Department, Ministry of Environment. The plant construction was completed as scheduled in October 1986 and the total cost is approximately $200 million.
It is capable of incinerating 2000 tonnes of refuse each day. This brings the total tonnage of refuse incinerated in Singapore from an average of 1300 tonnes to 3300 tonnes per day. This figure is 65% of the total amount of refuse generated daily in the nation.
To make the best use of refuse, the heat released from combustion process is used to generate electricity. The amount of power output not only supports the operational needs of the plant itself, but the excessive power is also sold to the local electrical power company which then redistribute the power for commercial, industrial and residential uses.
Moreover, the ferrous scrap is extracted from the ash and then sold to the material recycle factories in order not to waste the resources and to strengthen the finance of the incineration plant.
The following lists the design data and the major equipment of the Tuas Incineration Plant :
Plant Design Data :
Plant Capacity : 2000 tonnes per day Number of Incinerator Units : 5 Average Calorific Value of Refuse : 6000 kJ/kg Steam Generated per boiler : 42 tonnes/hr Live Steam Pressure : 35 bar Live Steam Temperature : 375 degree Celsius Power Generation Capacity : 30 MW Generator Voltage : 6.6 kV
Main Plant Equipment :
Refuse Handling : 3 weighbridges of 40 tonnes capacity each 23 refuse discharge bays 3 refuse cranes using rope-operated multi-polyp grab of 8m3 capacity each 1 bulky waste rotary shear of 20t/hr capacity 1 bulky waste cutter shear of 20t/hr capacity
Refuse Incineration & Steam Generation : 5 Martin stoker furnace units with integral boilers
Flue Gas Handling : 1 three-zone electrostatic precipitator to each boiler unit with a dust separation efficiency of 99.5% 1 reactor for flue gas conditioning to each unit 1 concrete chimney, 150m high, with fire-brick inner-lining.
Ash Handling Plant : 2 pusher-type ash extractors to each unit
Scrap Metal Recovery Plant : 2 magnetic separators to each unit
Power Generation : 2 condensing turbines 2 generators of 23 MW rated capacity each
Steam Condensation : 2 air condensers with 8 fans each
Cooling System : Closed loop cooling water
To be a little bit more technical, here comes the detailed descriptions of the refuse handling steps taken in the actual running of the Tuas Incineration Plant :
Refuse container trailers and refuse collection vehicles are first weighed at the weighbridges before they are permitted to discharge the refuse into the bunker through one of the 23 refuse discharge bays. Refuse in the bunker is then fed into the incinerator furnaces by means of grab-cranes.
Refuse combustion is an exothermic process and it can be sustained without the need for auxiliary fuel. Before refuse can be fed into the furnace, the temperature of the furnace must be raised using industrial diesel burners. The normal operating temperature in the furnace is about 1000 degrees Celsius.
Each incinerator furnace has 4 incineration grates which spread and transfer the burning refuse slowly through the furnace. Air drawn from the refuse bunker is preheated by superheated steam and introduced into the furnace through the underside of the incineration grates.
The flue gas produced in the combustion process is used to generate steam. Superheated steam from the boiler is expanded through two condensing turbines, each of which drives a generator to produce electricity. Part of the electricity generated is used to operate the Plant and the surplus is sold to the Public Utilities Board.
The incinerator and turbo generator units together with their auxiliary equipment are operated and monitored via CRTs from a central control room. Illuminated mimic diagrams show the status of essential equipment and closed circuit TV monitors the combustion status of each incinerator unit. Combustion conditions in the furnace are controlled automatically by a digital control system which regulates the air distribution in the furnace and adjusts the feeding rate of refuse according to its heating value.
The ash residue from the furnace is transported to the ash pit via vibrating conveyors. Ferrous scrap metal is picked up from the ash by overhead electromagnetic separators and sold as scrap.
The flue gas leaving the boiler flows through an electrostatic precipitator which is designed to remove up to 99.5% of the dust content in the flue gas. The clean flue gas is emitted through a 150m tall chimney.
The Need for Waste Minimisation
Waste
Waste is defined as something that is rejected because it is deemed to be worthless or unneeded.
Sources of Waste
Waste generated in Singapore is broadly classified into two categories. They are:
(a) Domestic and Trade Waste- It is collected from residential premises, markets, food retail outlets, schools and trade premises.
(b) Commercial and Industrial Waste- It is collected from commercial and industrial premises, construction sites and shipyards.
Waste Disposal
In Singapore, about 90% of the waste is incinerated and the remaining non-incinerable waste is land filled. Prior to 1979, all waste was disposed of at landfills. To reduce the over-reliance on landfills and the fact that most of our waste is combustible and suitable for incineration, our first incineration plant was built in 1979 at Ulu Pandan.
At present, we have four incineration plants in Singapore. They are located at Ulu Pandan, Senoko, Tuas and Tuas South. The Tuas South Incineration Plant is one of the largest in the world.
Although incineration can reduce the volume of incinerable waste, we still need to landfill the non-incinerable waste and incineration ash which is the residue of the incineration process. Our former landfill sites had reached their design capacities. They were the Tampines Dumping Ground, Choa Chu Kang Dumping Ground, Kok Sek Lin Dumping Ground, Lim Chu Kang Dumping as well as the Lorong Halus Dumping Ground which was closed on 1 Apr 1999. Now, Pulau Semakau, the first offshore landfill, is the only landfill in Singapore. It started its operation on 1 Apr 1999. Everyday, we have to barge our non-incinerable waste and incineration ash toPulau Semakau via the Tuas Marine Transfer Station.
Problems Faced in Waste Disposal
Although we can reduce the volume of incinerable waste significantly by incineration, it is not a sustainable solution to manage waste and the environment for the following reasons:
Escalation of waste output
Land-scare Singapore
Costly waste disposal facilities
Save the environment
Escalation of waste output
Over the last 30 - 40 years, Singapore has transformed herself to an urbanised, industrialised and affluent country. This has led to a rising trend in our waste output. Our waste output has been escalating rapidly. In 1970, a total of 0.46 million tonnes of waste was disposed, whilst in 2005, a total of 2.55 million tonnes of waste was disposed. There is a 2.09 million tonnes increase in the amount of waste over a 35-year span. This growth in solid waste generation places considerable demands on waste management, disposal facilities and the environment.
Land-scarce Singapore
Singapore is well known for its clean and green city. However, our main land is only 682.7 sq km in area. Singapore is just a tiny state on the map and lacks land resources. Land is required for constructing factories, warehouses, schools, houses and recreational amenities etc. It is extremely difficult to find land in land-scarce Singapore to construct incineration plants and landfills. We have therefore resorted to build the first offshore Pulau Semakau landfill. The lifespan of Pulau Semakau is expected to last 30 years till 2030. If the rising trend of waste generation is not curtailed, the lifespan might be shorter than 30 years. Therefore there is a need to prolong the lifespan as long as possible.
Costly waste disposal facilities
It is expensive to construct, operate and maintain incineration plants and landfill. Way back in 1979, it cost only $130 million to construct an incineration plant while the fourth plant at Tuas South cost about $900 million. Moreover, some $610 million was also spent to construct the landfill at Pulau Semakau.
Table 1: High Construction Costs of Incineration Plants
Location of Incineration plant
Year, Construction Cost, Capacity (Tonnes/Day)
Ulu Pandan
1979, $130 million , 1100
Tuas
1986, $200 million , 1700
Senoko
1992, $560 million , 2400
Tuas South
2000, $900 million , 3000
Save the environment
Wasteful consumption patterns also exploit and diminish the natural resources. The waste also poses harmful effects to the environment, polluting the air and land. In order to save the living environment and conserve the natural resources, there is an obligation for the community to minimise waste output and to recycle as much waste as possible. For instance, recycling of paper reduces air pollution by 74% and water pollution by 35%. Each ton of paper recycled could also save 17 small trees.
Moreover, the ferrous scrap is extracted from the ash and then sold to the material recycle factories in order not to waste the resources and to strengthen the finance of the incineration plant.
History of Semakau Landfill
In 1999, when the last remaining landfill on Singapore’s mainland was exhausted, the Semakau Landfill was created by enclosing Pulau Semakau and a small adjacent island (Pulau Sakeng) with a rock bund. All our waste now ends up at Semakau, i.e., ash from the incineration plants and all non - incinerable waste.
During the construction of the landfill, effort was made to protect the marine ecosystem, especially mangroves and corals. 13 hectares of mangrove were replanted to replace those removed during construction of the bund. Wildlife continues to thrive on Pulau Semakau, and the air and water quality remains good.
Semakau opened!
On 16 Jul 05, Pulau Semakau was opened for nature-related recreational activities. Members of the public can now visit the island for bird watching, sports fishing and intertidal walks. Marine life of Pulau Semakau
The original Pulau Semakau which was not affected by the landfill construction has an enormous inter tidal area which is rich in amazing wildlife. The natural mangroves there shelter a wide variety of plants and animals, many no longer seen on the mainland or other islands. There is a vast sea grass lagoon, possibly the largest in Singapore. The coral reefs that line the edge of the island also thrive with marine life. Here's some posters of Semakau's inter tidal shores and more about a survey of Semakau's mangroves in 2005.Getting there
Currently, you can only visit Pulau Semakau by joining activities conducted by designated interest groups.
Δεν υπάρχουν σχόλια:
Δημοσίευση σχολίου