ENVIRONMENTAL NOISE MODELLING
iFluids Engineering will perform environmental noise modeling study for the project based on project noise abatement philosophy, equipment layout design, baseline noise level and available key noisy equipment data sheets.
The main objective of this study is to ensure that the environmental noise level generated from operation of the facility will not exceed the acceptable ambient noise level outside the facility premises/fence line (at nearest noise sensitive receptors, in particular residential communities to the west of the project site).
The noise modelling study will be conducted using Cadna A, a professional and leading software for calculation, presentation, assessment and prediction of environmental noise. The model software calculates the contribution from each noise source, input as a specified source type (e.g. point, line, area, etc.) octave band sound power level, at selected locations. It predicts noise levels under light down-wind conditions based on hemispherical propagation, atmospheric absorption, ground effects, screening and directivity based on the procedure detailed in the ISO9613 “Acoustics – Attenuation of Sound During Propagation Outdoors”.
Typical noise study process will include:
- Review of facility document, layouts, specifications, equipment noise data sheets, background noise levels;
- Identification of modeling scenarios (e.g. normal operation, non-routine operations, emergency operations, etc.)
- Calculate predicted environmental noise level using Cadna A software and generate noise contour maps (including cumulative noise from baseline conditions) outside the plant fence line up to/at nearest noise sensitive receivers (showed on contour maps);
- Carry out an assessment of noise levels at identified noise sensitive receivers;
- Develop/create the model by digitising the layouts in the software using the latest project layout drawings provided by COMPANY. The noise sources will be highlighted and the relevant noise level data/equipment features will be incorporated in the model input files.
- Following completion of the model development, the CONSULTANT will run the noise model software to predict the noise levels during various operation of the facilities/equipment. A colour coded noise level contours will be developed and presented as 70 dB (A) and above in 5 dB increments.
- Following the development of the contours, the CONSULTANT will perform environmental noise impact assessment and identification of areas where noise levels may exceed allowable ambient noise limits around the plant site, the sources giving rise to the exceedances and recommendations for remedial noise mitigation measures based on noise control hierarchy in QP standards.
Figure: Example of Noise mapping using Cadna A software
A “Noise Study Report” will be prepared, complete with predicted sound pressure level contour maps and outline noise control recommendations