Report - Agence canadienne d'évaluation environnementale

Impacts on the inhabited area and human activities
Table 15 Maximum concentrations of air contaminants outside project
property limits during LNG terminal operation
Contaminant
Carbon monoxide
(CO)
Sulphur dioxide
(SO2)
Nitrogen dioxide
(NO2)
Total particulates
matter (TPM)
Terminal and jetty with LNG tanker and tugs Standard
Baseline 1
(µg/m 3 )
Operation 2
(µg/m 3 )
Total 3
(µg/m 3 Time
)
period
RQA
(µg/m 3 )
PRAA
(µg/m 3 )
17,000 746 17,746 1 hr. 34,000 34,000
9,100 222 9,322 8 hr. 15,000 12,700
107 168 275 1 hr. 1,310 276 4
73 40 113 24 hr. 288 288
152 191 343 1 hr. 414 414
90 i46 136 24 hr. 207 207
29 1.4 30.4 1 yr. 103 103
91 9.4 100,4 24 hr. 150 –
34 0.40 34.4 1 yr. 70 –
Fine particulates
(PM2.5)
20 7.5 27.5 24 hr. – 30
Benzene 5 0.02 5.02 24 hr. – 10
Formaldehyde 10 0.61 10.61 4 min – 37
1. Baseline: maximum values measured in the ambient air for contaminants in gaseous state at the Des Sables
station (CO, SO2 and NO2) and for TPM at the De L’Église station from 2001 to 2003. For PM2.5, the baseline is
that specified by the MDDEP (PR5.1, QC-78 and Appendix H of the PRAA). For benzene and formaldehyde, the
baseline corresponds to levels that are typical semi-urban areas of Québec.
2. Maximum values calculated within the modelling range, but outside the property limits. These values coincide
with the residential district north of Highway 132 at the top of the cliff.
3. Total: sum of maximum concentrations in the ambient air during operations based on the assumption that they
occur simultaneously.
4. 525 µg/m 3 over 4 minutes, i.e. the equivalent of 276 µg/m 3 on an hourly basis, applying the appropriate formula
contained in Appendix H of the PRAA.
Sources: adapted from PR3.3.1, table 6.2; PR5.1, Appendix H, Table H.8; PR5.2.1, QC-69s2; Regulation respecting
the quality of the atmosphere and Draft Air Quality Regulation.
Sulphur dioxide (SO2)
The addition of SO2 to the ambient air during terminal operation, especially when an
LNG tanker is present, could result in air quality standards being exceeded. The risk
would specifically affect homes located in areas overlooking the jetty and LNG tanker
stacks. Those living by the shore would mainly be exposed to SO2 when unfavourable
weather conditions put them in the plume of fumes from auxiliary generators
evacuated through the LNG tanker stacks. These electrical generators feed the
unloading pumps and the LNG tankers when they are berthed at the jetty.
Rabaska Project – Implementation of an LNG Terminal and Related Infrastructure 191