l'express du 22/03/2006
By Jean-Mée DESVEAUX
To say that Gamma Civic’s boss has a great power of persuasion would be the understatement of the year. Mr Tommy Ah Teck’s knack in that respect is nothing short of miraculous.
Adhering strictly to the technical facts outlined in the Final Feasibility Report: Environmental Solid Waste Management Project submitted to the Ministry of Local Government in March 2005 by Carl Bro International, we showed conclusively that an incineration project in Mauritius is by far and away a costlier, more dangerous and messier affair than using the available landfill site at Mare-Chicose to cater for our municipal solid waste (MSW) until around 2040.
Presumably caught unawares when he expected it least and chagrined by our conclusion, Mr Ah Teck allowed a technical debate to degenerate into name-calling. We won’t follow him into the sewers that he apprehends for reasons best known to him. The reader will therefore browse through Carl Bro’s report below to make up his-her own mind whether what we described last week was the emanation of a wayward imagination. He-she has a mighty surprise waiting for him-her at the end! (Emphasis added)
“The timing of a later
introduction of incineration
cannot be established at
present, but seems likely to be
beyond 2012, if at all within
the planning period analysed
(2004-2034)”
1) General desirability of incineration (page 27):
“Incineration of municipal solid waste is not feasible in Mauritius at present. Incineration is costly and no justification can be found for these costs as long as Government is committed to provide the required landfill capacity. The timing of a later introduction of incineration cannot be established at present, but seems likely to be beyond 2012, if at all within the planning period analysed (2004-2034). Favourable changes in the MSW properties, and (…) reduced environmental impact of new concepts and technologies in energy-from-waste plants can be expected over this period.”
2) On the low net calorific value and moisture composition of MSW:
a) “the consensus is that the (local) waste is higher in inherent moisture than usual for MSW incinerator design elsewhere, mostly because of the high organic component from kitchen and yard wastes. This gives a low average net calorific value (7.5 MJ/KG or lower) which is subject to further deterioration during times of heavy rainfall (…) Below 7.5 MJ/KG, it is expected that incineration would have to be frequently sustained with auxiliary fuel, and would also have a lower boiler efficiency, which means that an already costly treatment method will be even more expensive.” (P 21)
b) “Sidec-Arup 1998 study’s projection on future calorific values gave annual averages of 6.68 MJ/KG for 2001, 6.85 MJ/KG for 2006 and 7.159 MJ/KG for 2011”. (P 103)
c)“The University of Mauritius has shown that MSW is dominated by organic component consisting of kitchen-vegetable wastes; garden green waste. Combustion of wet wastes (…) which may have 50% to 90% moisture content, can even be a net absorber of heat energy – not a source of energy release – because of the need to evaporate the water.” (P 102/103)
d) “Incineration may be an appropriate solution for Mauritius in the (long-term) future, but it should be assessed again only when the effects of recycling and composting are known, when the average calorific value is expected to be considerably higher than today and also less liable to extreme variations. At present and during the planning period, the availability of landfill sites should continue to offer a much lower cost for disposal. When that situation ceases to apply, new concepts for energy-from-waste facilities of lower cost and greater public acceptability may have become commercially proven...” (P 22).
e) “The local high organics and high moisture MSW of low and time variable net calorific value is not ideally suited to incineration. Equipment can be designed to deal with it, with the addition of support fuel (…) but handling costs and (…) plant efficiencies would undoubtedly be less favourable for the incineration option than if it were of higher and more consistent quality”. (P 106).
f) (And this is important for a claim made by Mr Ah Teck who, probably through an oversight, exposes only the side of the truth that suits him):
Through “small scale composting plant due to open at some point in 2005, there are projections that 25% of the organic components could be recovered by 2014 (…) a reduction in the moisture level of this waste (…) should increase the NCV by more than 1 MJ/KG in the average waste received (…) to bring potential incinerator design into the normal range of plant experience.” (P 106). In other words, with composting (that has barely started), one of the several objections to the incineration technology may start to disappear from the scene in eight years time. But Gamma is starting to build in January 2007!
3) On the relationship between the low calorific composition of the waste and emission of carcinogenic dioxin:
a) “These low average and extreme calorific values would require special design features in an incineration plant since they lie outside the normal operating experience of most application of mass-burn technology…In addition, the high moisture level leads to much higher exhaust gas flow rates and hence boiler passages… For dioxin control (…) a minimum of 850 deg C for at least 2 seconds residence time of the exhaust gases (is required). For calorific values below 7.5 MJ/KG it may be necessary to provide combustion support by burning fuel oil in order to maintain these conditions”. (P 104).
b) Table 5.19 on page 108 shows that while the European Union (EU) directive 2000/76/EC stipulates a value of 0.1ng/m3 of dioxin emission into the air, the consultant believes that an incineration plant that burns the refuse that is available in Mauritius at present would in fact emit 1.0 ng/ m3, that is 10 times the permissible EU level. To the extent that the bigger plant size considered by the consultant is 150,000 tons or half the size considered by Gamma Civic, it would allow a degree of sorting out the type of waste it accepts. Gamma’s promise to treat indiscriminately 80% of the MSW would logically emit more dioxin.
c) “The chlorine present within the plastic component of the waste leads to relatively high concentration of HCL which require removal in order to meet the required design emission standards.” (P 108). Table 5.19 on that page shows that the value accepted by the EU directive for HCL is 10 while that acceptable in Mauritius is 200 and, best of all, a plant burning our local waste would emit between 1,100 and 1,400!
4) Cost consideration:
a) “The financial analysis shows that the lowest initial investments are required in the landfill – only scenario. Here the initial investments amount to $35.2 millions... Scenarios with MSW incineration are more costly from $US 78.9million to $110.4 million in total initial investments… The annual operating costs are also lowest for the landfill – only scenario with $3.74 compared to $ 5.52 and $6.86 (for the incineration scenarios). In terms of costs per tonnage of waste, the financial analysis estimates unit costs of $21 for MSW land filling and $88 and $117 for MSW (2 different sizes) incineration”. (P 24).
5) On the toxicity of the ash residues (another “erroneous allegation” of ours according to Mr Ah Teck. (P 113):
“The high heavy metal concentrations present in the ash residues often limits the potential utilization of the ash and when they are disposed of to landfill sites, leaching of pollutants may be a source of ground water contamination. Fly ash is more readily leached… and so is typically disposed of into synthetic or clay lined landfill sites… The contamination of fly-ash with heavy metals result in the ash being considered as a hazardous waste and requiring special permits for landfill disposal.”
6) On the desirability of Mare-Chicose:
“Being a soft site, Mare-Chicose provides the best features for a future Mega Landfill, (…) the existence of Mare-Chicose (…) presents a strong case for extended development.” (P 28).
Unfortunately for Mr Ah Teck, the above are facts based on scientific information gathered as recently as 2005, not “erroneous allegations” as he would like to claim. Facts don’t lie!
Or do they? For lo and behold! Mr Ah Teck tells us in his rejoinder that we should rest easy with his project since the feasibility of his incineration studies have been carried out by no other than…yes, Carl Bro International itself who, “hired as advisers for project analysis and in preparation for (Gamma’s) proposal” overturned, within a mere nine months, every single conclusion that they had given their imprimatur to.
Thus, according to Mr Ah Teck, within the span of nine months Carl Bro concluded in a report to Gamma in December 2005:
1) “Waste incineration with energy generation seems to be a realistic and advantageous waste treatment option in Mauritius.”
2) Incineration “can be accomplished today for less than half the amounts” quoted by Carl Bro a few months before.
3) “Based on evaluation of Carl Bro these revised costs for (incineration of) solid waste disposal are roughly comparable with those of a new landfill…”
As we said above, Mr Ah Teck is matchless. However, in view of the public importance of this project of Rs 4.5 billion, instead of putting to rest our misgivings, the chief executive of Gamma Civic has increased them a thousand fold. How on earth can such an unparalleled reversal of professional opi-nion by Carl Bro International take place in such an indecently short lapse of time.
While we acknowledge that there is great civic virtue in endeavouring to treat the rubbish of our little nation, until such plans get off the ground if a gullible government permits, we should not be treated with the unadulterated rubbish of the virtual kind.
By Jean-Mée DESVEAUX
To say that Gamma Civic’s boss has a great power of persuasion would be the understatement of the year. Mr Tommy Ah Teck’s knack in that respect is nothing short of miraculous.
Adhering strictly to the technical facts outlined in the Final Feasibility Report: Environmental Solid Waste Management Project submitted to the Ministry of Local Government in March 2005 by Carl Bro International, we showed conclusively that an incineration project in Mauritius is by far and away a costlier, more dangerous and messier affair than using the available landfill site at Mare-Chicose to cater for our municipal solid waste (MSW) until around 2040.
Presumably caught unawares when he expected it least and chagrined by our conclusion, Mr Ah Teck allowed a technical debate to degenerate into name-calling. We won’t follow him into the sewers that he apprehends for reasons best known to him. The reader will therefore browse through Carl Bro’s report below to make up his-her own mind whether what we described last week was the emanation of a wayward imagination. He-she has a mighty surprise waiting for him-her at the end! (Emphasis added)
“The timing of a later
introduction of incineration
cannot be established at
present, but seems likely to be
beyond 2012, if at all within
the planning period analysed
(2004-2034)”
1) General desirability of incineration (page 27):
“Incineration of municipal solid waste is not feasible in Mauritius at present. Incineration is costly and no justification can be found for these costs as long as Government is committed to provide the required landfill capacity. The timing of a later introduction of incineration cannot be established at present, but seems likely to be beyond 2012, if at all within the planning period analysed (2004-2034). Favourable changes in the MSW properties, and (…) reduced environmental impact of new concepts and technologies in energy-from-waste plants can be expected over this period.”
2) On the low net calorific value and moisture composition of MSW:
a) “the consensus is that the (local) waste is higher in inherent moisture than usual for MSW incinerator design elsewhere, mostly because of the high organic component from kitchen and yard wastes. This gives a low average net calorific value (7.5 MJ/KG or lower) which is subject to further deterioration during times of heavy rainfall (…) Below 7.5 MJ/KG, it is expected that incineration would have to be frequently sustained with auxiliary fuel, and would also have a lower boiler efficiency, which means that an already costly treatment method will be even more expensive.” (P 21)
b) “Sidec-Arup 1998 study’s projection on future calorific values gave annual averages of 6.68 MJ/KG for 2001, 6.85 MJ/KG for 2006 and 7.159 MJ/KG for 2011”. (P 103)
c)“The University of Mauritius has shown that MSW is dominated by organic component consisting of kitchen-vegetable wastes; garden green waste. Combustion of wet wastes (…) which may have 50% to 90% moisture content, can even be a net absorber of heat energy – not a source of energy release – because of the need to evaporate the water.” (P 102/103)
d) “Incineration may be an appropriate solution for Mauritius in the (long-term) future, but it should be assessed again only when the effects of recycling and composting are known, when the average calorific value is expected to be considerably higher than today and also less liable to extreme variations. At present and during the planning period, the availability of landfill sites should continue to offer a much lower cost for disposal. When that situation ceases to apply, new concepts for energy-from-waste facilities of lower cost and greater public acceptability may have become commercially proven...” (P 22).
e) “The local high organics and high moisture MSW of low and time variable net calorific value is not ideally suited to incineration. Equipment can be designed to deal with it, with the addition of support fuel (…) but handling costs and (…) plant efficiencies would undoubtedly be less favourable for the incineration option than if it were of higher and more consistent quality”. (P 106).
f) (And this is important for a claim made by Mr Ah Teck who, probably through an oversight, exposes only the side of the truth that suits him):
Through “small scale composting plant due to open at some point in 2005, there are projections that 25% of the organic components could be recovered by 2014 (…) a reduction in the moisture level of this waste (…) should increase the NCV by more than 1 MJ/KG in the average waste received (…) to bring potential incinerator design into the normal range of plant experience.” (P 106). In other words, with composting (that has barely started), one of the several objections to the incineration technology may start to disappear from the scene in eight years time. But Gamma is starting to build in January 2007!
3) On the relationship between the low calorific composition of the waste and emission of carcinogenic dioxin:
a) “These low average and extreme calorific values would require special design features in an incineration plant since they lie outside the normal operating experience of most application of mass-burn technology…In addition, the high moisture level leads to much higher exhaust gas flow rates and hence boiler passages… For dioxin control (…) a minimum of 850 deg C for at least 2 seconds residence time of the exhaust gases (is required). For calorific values below 7.5 MJ/KG it may be necessary to provide combustion support by burning fuel oil in order to maintain these conditions”. (P 104).
b) Table 5.19 on page 108 shows that while the European Union (EU) directive 2000/76/EC stipulates a value of 0.1ng/m3 of dioxin emission into the air, the consultant believes that an incineration plant that burns the refuse that is available in Mauritius at present would in fact emit 1.0 ng/ m3, that is 10 times the permissible EU level. To the extent that the bigger plant size considered by the consultant is 150,000 tons or half the size considered by Gamma Civic, it would allow a degree of sorting out the type of waste it accepts. Gamma’s promise to treat indiscriminately 80% of the MSW would logically emit more dioxin.
c) “The chlorine present within the plastic component of the waste leads to relatively high concentration of HCL which require removal in order to meet the required design emission standards.” (P 108). Table 5.19 on that page shows that the value accepted by the EU directive for HCL is 10 while that acceptable in Mauritius is 200 and, best of all, a plant burning our local waste would emit between 1,100 and 1,400!
4) Cost consideration:
a) “The financial analysis shows that the lowest initial investments are required in the landfill – only scenario. Here the initial investments amount to $35.2 millions... Scenarios with MSW incineration are more costly from $US 78.9million to $110.4 million in total initial investments… The annual operating costs are also lowest for the landfill – only scenario with $3.74 compared to $ 5.52 and $6.86 (for the incineration scenarios). In terms of costs per tonnage of waste, the financial analysis estimates unit costs of $21 for MSW land filling and $88 and $117 for MSW (2 different sizes) incineration”. (P 24).
5) On the toxicity of the ash residues (another “erroneous allegation” of ours according to Mr Ah Teck. (P 113):
“The high heavy metal concentrations present in the ash residues often limits the potential utilization of the ash and when they are disposed of to landfill sites, leaching of pollutants may be a source of ground water contamination. Fly ash is more readily leached… and so is typically disposed of into synthetic or clay lined landfill sites… The contamination of fly-ash with heavy metals result in the ash being considered as a hazardous waste and requiring special permits for landfill disposal.”
6) On the desirability of Mare-Chicose:
“Being a soft site, Mare-Chicose provides the best features for a future Mega Landfill, (…) the existence of Mare-Chicose (…) presents a strong case for extended development.” (P 28).
Unfortunately for Mr Ah Teck, the above are facts based on scientific information gathered as recently as 2005, not “erroneous allegations” as he would like to claim. Facts don’t lie!
Or do they? For lo and behold! Mr Ah Teck tells us in his rejoinder that we should rest easy with his project since the feasibility of his incineration studies have been carried out by no other than…yes, Carl Bro International itself who, “hired as advisers for project analysis and in preparation for (Gamma’s) proposal” overturned, within a mere nine months, every single conclusion that they had given their imprimatur to.
Thus, according to Mr Ah Teck, within the span of nine months Carl Bro concluded in a report to Gamma in December 2005:
1) “Waste incineration with energy generation seems to be a realistic and advantageous waste treatment option in Mauritius.”
2) Incineration “can be accomplished today for less than half the amounts” quoted by Carl Bro a few months before.
3) “Based on evaluation of Carl Bro these revised costs for (incineration of) solid waste disposal are roughly comparable with those of a new landfill…”
As we said above, Mr Ah Teck is matchless. However, in view of the public importance of this project of Rs 4.5 billion, instead of putting to rest our misgivings, the chief executive of Gamma Civic has increased them a thousand fold. How on earth can such an unparalleled reversal of professional opi-nion by Carl Bro International take place in such an indecently short lapse of time.
While we acknowledge that there is great civic virtue in endeavouring to treat the rubbish of our little nation, until such plans get off the ground if a gullible government permits, we should not be treated with the unadulterated rubbish of the virtual kind.
