Environmental Assessment
Volume B-3.4
Mine
Climate and Air Quality
Ambatovy Project
51
January 2006
Table 3.4-6 presents a summary of the estimated emissions from the mine.
Table 3.4-6 Mine Air Emissions Summary
(b)
Emission Rate [t/d]
Source
SO
2
NO
X
PM
10
TSP
diesel generators
0.35
2.37
0.06
0.07
mine fleet
0.42
1.59
0.06
0.06
road dust
0.00
0.00
0.21
0.70
fugitive dust
0.00
0.00
0.06
0.22
total
(a)
0.77
3.96
0.39
1.06
(a)
Some numbers are rounded for presentation purposes. Therefore, it may appear that the totals do
not equal the sum of the individual values.
(b)
Based on data provided in volume I, Appendix 4.2.
Note: Trace metals are scaled off of particulate predictions based on metal content of ore and diesel
fuel; therefore, emissions are not presented.
Mitigation
The air quality assessment of the mine is based on the mining year with the
highest fuel consumption. The proponent has committed to using Tier 2 mine
fleet vehicles which have lower NO
X
emissions. The U.S. Government and
engine manufacturers have worked together to develop a four-tiered system for
regulating emissions of NO
X
, particulates, carbon monoxide and total
hydrocarbons from diesel engines. Since 1996 and the beginning of the
implementation of Tier 1 emission standards, consistently more stringent
regulations will be implemented in stages. The Tier 2 standards come into effect
for off-road diesel engines greater than 750 hp in 2006. The proponent has also
committed to reducing dust generated by vehicle traffic by watering roads.
Results
Key Compounds
The expected emissions of SO
2
, NO
X
, TSP, PM
10
and trace compounds from the
mine were input into the CALPUFF dispersion model to determine ground-level
concentrations across the study area and at selected regional communities. The
CALPUFF model was run in the steady-state (2-D) mode using two years of
meteorological observations from the on-site meteorological station. A summary
of the modelling results are presented in Table 3.4-7. The results are also shown
graphically in Volume I, Appendix 4.2.
The annual TSP predictions are slightly below the World Bank criteria of
80 µg/m³. These predictions are likely conservative since the roads on-site will
