Environmental Assessment
Volume B-3.4
Mine
Climate and Air Quality
Ambatovy Project
47
January 2006
Table 3.4-4 Magnitude Classifications for Air Quality
Magnitude
(a)
Parameter
Negligible
Low
Moderate
High
24-hour SO
2
concentration [µg/m³]
no increase
≤ 25
≤ 500
> 500
annual SO
2
concentration [µg/m³]
no increase
≤ 5
≤ 100
> 100
24-hour NO
2
concentration [µg/m³]
no increase
≤ 10
≤ 200
> 200
annual NO
2
concentration [µg/m³]
no increase
≤ 5
≤ 100
> 100
annual TSP concentration [µg/m³]
no increase
≤ 4
≤ 80
> 80
24-hour PM
10
concentration [µg/m³]
no increase
≤ 25
≤ 500
> 500
annual PM
10
concentration [µg/m³]
no increase
≤ 5
≤ 100
> 100
annual lead concentration [µg/m³]
no increase
≤ 0.025
≤ 0.5
> 0.5
annual mercury concentration [µg/m³]
no increase
≤ 0.05
≤ 1
> 1
(a)
The magnitude is based on the maximum prediction values outside the property boundary.
Table 3.4-5 shows the screening system for determining environmental
consequence. This screening system is based on the fact that the geographic
extent of the air quality impacts are local, direction is negative, the duration is
medium-term (3 to 30 years) and the impacts are reversible.
Table 3.4-5 Air Quality Screening System of Environmental Consequences
Magnitude
Frequency
Environmental
Consequence
negligible
all
negligible
low
low
low
low
moderate
low
low
high
low
moderate
low
low
moderate
moderate
low
moderate
high
low
high
low
moderate
high
moderate
moderate
high
high
moderate
Note: Screening system based on the fact that the geographic extent is local, direction is negative
and the impacts are reversible.
