International Review of Waste Management Policy - Department of ...

kg kg 1,4-dichlorobenzene 1,4-dichlorobenzene eq.
eq.
methane emissions – considered in terms of kg of methane emitted per kg of
stabilised waste - is assumed to be exactly the same as that of the non-stabilised
material. WRATE does take into account the reduction in mass which occurs in
material which is biologically pre-treated as a result of moisture loss, and this leads to
a reduction in the landfill emissions – but it does not account for reduction in
biodegradability, so the emissions are reduced only to a limited extent. The model,
therefore, significantly underestimates the extent to which the biological component
of the MBT process reduces the biological activity of material subsequently sent to
landfill, biasing any assessment of residual waste facilities against this criterion. 1192
Any MBT process which stabilises waste prior to landfilling is effectively penalised by
the shortcomings of the model.
62.1.1.3 Human Toxicity Potential
The human toxicity potential is an index intending to reflect the potential harm of a
unit of chemical released, based both on the inherent toxicity of the chemical and its
potential dose. The default impact assessment in WRATE considers these impacts in
terms of kg 1,4 dichlorobenzene equivalent.
Our analysis shows that landfill performs relatively well against this assessment
criterion. The worst performing facility in this case is the Dundee incinerator, and
thermal treatments appear less favourable in comparison to the MBT options (with
the exception of the Chineham incinerator).
Figure 62-3: Human Toxicity (HTP inf)
80.00
60.00
40.00
20.00
0.00
-20.00
-40.00
968
29/09/09
0.98
3.30
Landfill Ecodeco
MBT
12.10
Generic
Aero MBT
Generic
-5.32
AD MBT
14.40
AD
Arrowbio
MBT
Incin Elec
C
-27.10
70.60
Incin Elec
D
29.80
Incin Elec
B
39.50
Incin CHP
C
40.60
Incin CHP
G
1192 This is a problem of the model, related to the fact that WRATE does not incorporate a landfill model
per se, rather emissions are hard-coded into the model.