Azura-Edo Independent Power Plant Environmental Impact ... - IFC

There are no technical details to support this conclusion, that is, no assessment
and calculation methodology were given in the EIA for the neighbouring
NIPP plant.
Table 9.2
Comparison of Significant Noise Sources in Design, Azura, NIPP
Noise Source
Noise Specification
Azura
NIPP
OCGT (Turbines) 82 dB(A) @ 1m 85 dB(A) @ 1m
Turbine Building Design Double skin cladding or equivalent No building
Waste Heat Stack 92 dB(A) Lw 1 No specification 2
Fin Fan Coolers 85 dB(A) @ 1m 85 dB(A) @ 1m
Note 1: Sound Power level re 10 -12 Watts
Note 2: NIPP plant noise source assumed to be 85 dB(A) at 1m.
Therefore to effectively determine the cumulative noise impact from both the
Azura Edo Plant and the NIPP plant, the assumptions shown in Table 9.2 have
been used to predict the cumulative noise levels from both plants. Figure 9.3
shows that the cumulative noise emission levels remain below 45 dB(A)
LAeq, 1hr at all receptors within the three communities, except for the four
farms identified within the Orior-Osemwende community.
The noise levels at the northern-most farm is predicted at 47 dB (A), while
levels at the three farms to the south are predicted to be 49 dB(A), and are
predicted to experience noise levels in compliance with the day time limit of
55 dB(A) LAeq, 15hr but to exceed the night time limit of 45 dB (A) LAeq, 1hr.
Table 9.3 presents the individual contributed noise from the Azura Edo IPP
and NIPP plants as well as the cumulative noise level at the four farm
locations. It is evident that the cause of the excessive noise is attributable to
the calculated noise emission from the NIPP plant and further mitigation of
the Azura Edo IPP plant would be fruitless as long as the noise attributable to
the NIPP plant exceeds 42 dB(A). If the NIPP and Azura Edo IPP Plant
contribute 42 dB (A) at these receptors, the cumulative noise level would 45
dB (A).
Table 9.3
Cumulative Noise at Farms
ID
Description
Predicted Noise Level, dB(A), LAeq, 1hr
Azura NIPP Azzura + NIPP
SN_116 Farm 4 38 46 47
SN_142 Farm 3 41 48 49
SN_150 Farm 2 40 48 49
SN_156 Farm 1 42 49 49
The noise impact at these farms are considered to be of major significance
prior to mitigation, as the noise levels exceed 45 LAeq, 1hr and existing
background noise levels have been increased by greater than 3 dB (A). This
AZURA EDO IPP
9-5
DRAFT EIA REPORT