MEMORANDUM BY PROFESSOR ANDREW PORTEOUS
(DSW 01)
1. It is clear that with UK MSW growth rates
approaching at 4 per cent and currently not decreasing, that achieving
the Waste Management Strategy of 40 per cent recovery by 2005
and 67 per cent by 2015 with an integral component 25 per cent
and 33 per cent recycling/composting[1]
is a very tall order.
2. All the waste management options of reduce,
reuse, recycle, recover need to be brought into play and dogmatic
rejection of anything that smacks of energy from waste incineration
(EFWI) as evidenced by various pressure groups statements (for
example [1]) is not conducive to integrated waste management whereby
circumstances such as proximity to markets for recycled materials,
cost effectiveness environmental effects must all be considered.
Modern developments in EFWI need to be taken on board and not
ignored [2].
3. This thinking has, for example, been
practised by Cornwall who analysed their looming waste crisis
under three scenarios as per Table 1 [3].
Table 1
CORNWALL'S WASTE MANAGEMENT "SCENARIOS"
FOR TOTAL WASTE ARISINGS OF 406 KT/YR (MSW 252 KT/YR)
| Scenario | Reduce
| Recycle/Compost | Recovery
| Landfill |
| Existing | — | 12 kt/yr
| — | 394 kt/yr |
| Friends of the Earth | 12 kt/yr
| 308 kt/yr | — | 128 kt/yr
|
| Integrated | 8 kt/yr | 55 kt/yr
| 150 kt/yr | 191 kt/yr |
Cornwall's assessment using the Best Practicable Environmental
Option approach to waste was to choose, and commend to the public,
that integrated waste management embracing EFWI, but not dominated
by it, was the BPEO choice.
4. Similar decisions will have to be made around the
UK, and it is not unlikely that EFWI will be called upon to play
its part. Already, Surrey, Avonmouth, Essex, E & W Sussex,
Kent, and London have posited/adopted EFWI as part of their respective
integrated waste management strategies. Norfolk's public consultation
document "Your Rubbish—Your Choice" epitomises
the dilemma (growth rate 4.75 per cent per year). When it states
"To meet recycling and Landfill Directive targets over the
next 20 years, Norfolk will have to build new plants such as Energy
from Wales, Recycling, Compost".
5. The purpose of this submission is to demonstrate that
modern EFWI is clean, green, safe and is compatible with practicable
recycling. It also conserves energy and mineral resources by delivering
a second bite at the cherry in that the bottom ash can be used
as an aggregate substitute; in effect, this provides 20-24 per
cent recycling of the input MSW plus 500 kWh of electricity per
tonne.
6. Table 2 gives factual data on today's modern EFWI
plant emissions performance and demonstrate what is now achievable.
The abysmal level of performance of yesterday's plants (pre 1996)
is also given. Along with percentage improvement effected.
Table 2
EMISSION CONTROL PERFORMANCE FOR ENERGY FROM WASTE PLANT
(UK RETROFIT) AND COMPARISON WITH 1991 EFWI PLANTS (MEAN VALUES)
| Component | Emission to air in mg/NM3—dioxins in mg/Nm3—dry gas 11% O2 Measured (1)Requirements EC Draft Incineration Directive (2)
| UK 1991 Mean Emissions mg/Nm3 (3) |
% Reduction COL (1)-COL (2) COL (3) (4) |
| Particulates | 0.9 | 10
| 500 | 99.8 |
| HC1 | 20 | 10
| 689 | 97.1 |
| HF | <0.1 | 1
| NA | — |
| SO2 | 36 | 50
| 338 | 89 |
| NOx as NO2 | 274 | 200 (plant>3 tph)
| NA | — |
| CO | 5 | 50
| 220 | 98 |
| VOC | <5 | 10
| NA | — |
| Hg | <0.02 | 0.05
| 0.26 | 99 |
| Cd | <0.001 | 0.05 (Cd and TI)
| 0.6 | 99.8 |
| 7HM (heavy metal summation) | <0.1
| 0.5 | >11.0 | 99
|
| Dioxin I-TEQ ng/Nm3 | 0.006
| 0.1 | >225 | 99.9
|
7. This outstanding performance in emissions reduction
(column 4) in today's EFWI plants compared with their obsolete
predecessors is due to several factors:
(a) thorough understanding of waste combustion and the
adoption of appropriate combustion regimes;
(b) high performance grate technology;
(c) the addition of activated carbon to the flue gas stream
to "sweep up" mercury, cadmium and any dioxins in alliance
with
(d) ultra high performance gas scrubbers and bag filters.
8. It is clear the improvements in performance of >99
per cent as demonstrated in Table 2 mean that perceptions acquired
during old plant operational regimes are obsolete, and also any
health data from these unsupportable regimes cannot be extrapolated
to today's plants. For example, epidemiological studies such as
that reported by Medical Research Council [4] found that "Epidemiological
studies of people who work or live near incinerators have shown
no consistent excess incidence of any specific disease" (one
study looked at over 14 million people between the years 1974
and 1987). Given this MRC finding, today's infinitely cleaner
plants must pose negligible health risks—as concluded by
the Committee on Carcinogenity of Chemicals in Food, Consumer
Products and the Environment (COC) [5] which stated that it was
"reassured that any potential risk of cancer due to residency—for
periods longer than 10 years—near to municipal solid waste
incinerators was exceedingly low and probably not measurable by
the most modern epidemiological techniques". There is no
need for further investigation "at the present time",
the committee maintained.
9. The health aspect needs a little more illustration
as scare headlines (which do not deserve further publicity) regularly
keep up a drum beat of innuendo, eg one newspaper (Sunday Mirror
23 July 2000) aired its new found fears over incineration
and health, based on an article in the International Journal of
Epidemiology [6] (which it is believed is not on every journalist's
bookshelf).
10. On detailed inspection of this vital new evidence,
it transpires "Because of their locations, the specific effects
of the municipal incinerators could not be separated clearly from
those of adjacent industrial sources of combustion effluents.
Both were probably carcinogenic. Landfill waste sites showed no
such effect", also the data refers to obsolete incinerators
and furthermore, the author concedes that the older incinerators
(pre 1955) "might be more toxic than more modern ones".
Furthermore examination [of the data] "seemed to exonerate
the more modern plants".—Indeed—So why the fuss?
11. Dioxins—a cautionary tale. Table 2 demonstrates
that dioxin emissions to air are now very small, and that compared
to the input quantity of 0.7 gm (TEQ) dioxins in 100,000 tonnes
of waste >98 per cent reduction is achieved. However, dioxins
are trapped in the EFWI's fabric filters and where they are immobilised
and landfilled in engineered landfilled sites. A dioxin balance
would show an increase in dioxins, but this takes no account of
their removal from the environment in the gas cleaning residues.
12. Burnley [7] has commented as follows:
"What are the dioxins levels in waste, waste processing
residues and composts and what confidence limits can we put round
these levels?
What is the environmental impact of the dioxins in landfilled
wastes and residues? (given the hydrophobic nature of dioxins
and present-day landfill standards it is reasonable to consider
incineration with landfill of the pollution abatement residues
to be an effective way of removing dioxins from the environment).
What is the environmental impact of the dioxins in waste-derived
composts when applied to gardens and agricultural land?
I would welcome any debate on how we should answer these questions,
but using my article [8] to suggest that we have any of these
answers directly contradicts my published conclusions".
13. One needs to look behind the figures and it is salutary
to note that dioxins in "compost" have received scant
attention so far. Certainly, composting is not a dioxin reduction
process. It would appear that a major dose of hypocrisy prevails
regarding EFWI, especially as secondary aluminium processing is
a major producer of dioxins to land too (still low to medium risk
to water) [9].—Far too much has been made of this topic
and a clearer perspective is required for all waste management
options.
14. Green Energy: Besides making use of waste that is
not practicably recyclable, EFWI effects both a CO2 displacement
saving (Table 3) and major particulate emissions saving compared
with coal fired power stations (which would be put on reduced
output because of the EFWI contribution).
Table 3
CO2 Displacement Saving
Typical CO2 emissions from industrial boilers are [10,11]
coal fired 410 g/kWh thermal or ca 950 g CO2 kWh electricity
gas fired 226 g/kWh thermal or ca 525 g CO2 kWh electricity
CCGT: ca 400 g CO2 kWh electricity
500 kWh/te waste are generated by an EFW plant (ie 264 g CO2/kWh)
[12]
Hence, the CO2 saving achieved by EFW electrical power generation
is
coal (950—264) = 686 g kWh electricity
gas (525—264) = 261 g/kWh electricity
CCGT (400—264) = 136 g/kWh electricity
Clearly, EfW achieves a significant nett CO2 reduction compared
with fossil fuelled power generation.
It also completely eliminates the powerful greenhouse gas, methane
(ca 1.5 mtpy) produced by the landfilling of MSW.—This has
a greenhouse effect factor 60 (20 year timescale).
15. Avoided Particulate saving data.
Given that EFWI will displace electricity generated by coal
fired power stations (as these are lower efficiency than gas fired
base load stations) then it is possible to calculate a typical
particulate emission loading per kWh for EFWI and compared this
with coal fired power generation. This has been done below:
— EFWI 1kWh is equivalent to 11 Nm3 of emissions
at typically 2 mg/Nm3. This is equivalent to a particulate loading
of 22 mg/kWh.
— Coal fired power stations data [13] indicate a
range of 80-350 mg/kWh. Clearly, EFWI achieves reductions of 82
to 94 per cent per kWh.
16. The basics of recycling needs to be re-thought, given
that most recycled materials are in great abundance (iron and
aluminium are minor contributions and the former is readily extractable)
or renewable and not depleted when managed properly eg the Finnish
Forest Balance is in substantial nett annual surplus [14].
The paper Federation [15] has commented on a major paper
recycling campaign as follows:
"The paper industry has devoted a great deal of time
and resources in recent years to trying to stabilise the waste-paper
market. The latest FoE campaign, based as it is on questionable
statistics and assumptions, will do nothing to assist this endeavour".
17. Also, there is documented evidence of collected (ie
"recycled") newsprint being tipped after collection
[16]. This is arrant nonsense. The Council Taxpayers deserve better
use of their money for Social Services, schools, hospitals, etc.
18. Plastics recycling is dodgy. True, shredded PET bottles
can make anorak fillers (what happened to good old natural wool/cotton,
both in abundance?) The major UK plastics film recycler runs at
a loss [17].
19. It would appear that unless "recycled"
primary materials from household waste confer major economic advantages
to manufacturers vis a" vis uncontaminated fresh,
readily available raw materials, then much of the recycling programme
is money down the drain (see for example, discussions by Porteous
in reference [18]).
20. A balance has to be struck between recycling and
EFW. Recycling may have detrimental urban environmental effects,
especially where a second collection vehicle is used. It also
has diminishing returns both economically and environmentally,
after the readily recyclable materials have been retrieved.
21. To conclude, as most of the resources in MSW are
renewable, in great abundance, or are beyond redemption through
contamination, recycling is only worthwhile if it:
Confers economic advantage to purchasers of materials or
products
Saves more oil/coal/natural gas, and
Produces less pollution impacts than alternative methods
of waste management whose costs of implementation are equal or
lower.
22. We may conclude that EFWI, as one of the most strictly
controlled combustion processes in Europe, can justifiably lay
claim to being the natural companion to practicable recycling/composting
and merits equal standing with them in the waste management hierarchy.
23. Delivery of the UK Waste Management Strategy requires
more EFWI capacity, appropriately sized, to permit practicable
recycling/composting.
We need rational and not emotional decision making
REFERENCES
(1) Oppenheimer S (FoE) Public Concerns are they justified?
NSCA Seminar Public Acceptability of Incineration RSA London 28
June 2000.
(2) House of Lords, Session 1997-98 Seventeenth Report
Select Committee on the European Communities "Sustainable
Landfill" Committee's comments para 143 p 38.
(3) Cornwall C C—County Environmental Services
Report "A Fresh Look at Cornwall's Waste" 2000.
(4) Medical Research Council, Institute for Environment
and Health. "Health Effects of Waste Combustion Products.
Report R7 1997.
(5) COC Committee Report Ref CoC/00/S1 on Incineration
and Health, Department of Health 4 February 2000.
(6) Knox E G "Childhood Cancer, Birthplaces, Incineration
and Landfill Sites". Intl Jl of Epidemiology 2000, Vol 29,
pp 39-39.
(7) Burnley S, personal communication 11 October 1999.
(8) Burnley S, Dioxins, Energy from Waste—Source
or Sink? Warmer Bull, 57, November 1997.
(9) Environment Agency R & D Publication 3, A Review
of Dioxin Releases to Land and Water in the UK. EA—1997.
(10) Department of Environment Good Practice Guide 116,
Environmental Aspects of large scales combined Heat and Power,
August 1994.
(11) Kyte W, Powergen Communication 20 December 1996.
(12) Porteous A, Energy from Waste, A Rigorous and Environmentally
Sound Option: Proc Inst Waste Management, March 1997, pp 20-28.
(13) National Power "Environmental Performance Review
2000. Emissions Data p 31, July 2000.
(14) Finnish Forest Industries Federation, 1999 Annual
Report.
(15) W J Bartlett, Director General, The Paper Federation
Letter to the Times "Price of Success in Waste Recycling"
2 July 1998.
(16) Leake J, "Waste Piles up as Recycling Slumps".
The Sunday Times 9 July 2000.
(17) British Polythene Industries Plc—Annual Report
1999.
(18) Porteous A, Dictionary of Environmental Science
and Technology, Third Edition. John Wiley Publishers, August 2000.
September 2000
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Not all "compost" is marketable and may end up as landfill
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