6.0. Noise and Vibration.

Transcription

1 6.0 Noise and Vibration

2 6.0 Noise and Vibration 6.1 Introduction 6.2 Assessment Methodology 6.3 Noise Sensitive Receptors 6.4 Expected Maximum Noise Emissions 6.1 Introduction This section aims to assess the impact of noise and vibration on nearby sensitive receptors resulting from the operation of the processes. Noise and vibration can have a significant effect on the environment and on the quality of life enjoyed by individuals and communities. In order to take a conservative approach, this assessment has been based upon the maximum anticipated noise emissions from the processes, whilst taking into consideration the existing building structure housing the operation. The potential impact of noise that can be generated by the operation has been a primary consideration through the design process and will be a key parameter in determining the locations for plant and machinery within the building. Assessments have been undertaken for both expected noise emissions from day time and night time operations. It is anticipated that due to the distance to the nearest noise sensitive receptors from the source, that the facility will not have a significant impact. 6.2 Assessment Methodology The assessment of potential noise and vibration impacts of the operations has been undertaken using anticipated noise emissions of the process. The potential impact of any noise generated is dependent on the existing background noise levels, the distance to the receptor from the source and any intervening noise or attenuation barriers. Vibration effects on buildings and structures may be considered in terms of their potential to cause damage. However, vibration levels at which even cosmetic damage can occur are relatively high and, generally, these are only generated by blasting or some construction activities in very close proximity to buildings. This facility will not cause any vibration that is discernible beyond the application site boundary to any sensitive receptors or nearby industrial units. The measurement and assessment of potential noise and vibration impacts have been undertaken using a combination of desktop studies, literature reviews and predictions. The focus of this assessment is based on British Standard 4142 Methods for rating and assessing industrial and commercial sound. The procedure outlined in this standard involves the comparison of the ambient noise level (LA eq) and background noise level (LA 90).

3 A difference of 0 db from background levels is unlikely to cause an adverse impact, a difference of 5 db from background is likely to cause an adverse impact and differences of 10dB or over from background levels could be considered to be a significant adverse impact. The Guidelines for Community Noise 2000 published by the World Health Organisation (WHO) specifies noise level limits during the day and night which should minimise perceived nuisance. General outdoor noise levels below 50dB LA eq during the day are desirable to prevent moderate annoyance. The guidelines also recommend a noise level of less than 45dB LA eq for night time periods in order to meet sleep disturbance criteria. The principal sources of noise and vibration identified include: - Noise and vibration resulting from normal plant operation activities. 6.3 Noise Sensitive Receptors The Noise Sensitive Receptors identified in Table 6.1 below are considered to be representative of the receptors most likely to be affected by the operation. LOCATION DISTANCE FROM EDGE OF UNIT Residential sections of Limassol (various) Nearest 460m Γυμνάσιο Αγίας Βαρβάρας (school) 480m On site employees and visitors Table 6.1 Noise Sensitive Receptors The locations of these sensitive receptors are shown on Drg D03 in Appendix A. 6.4 Expected Maximum Noise Emissions In order to adopt a conservative approach, a noise model has been developed for the industrial unit based on worst case scenarios during operational hours. A temporary generator with acoustic enclosure will be set up outside the facility, with an approximate Sound Pressure Level (SPL) of 69 dba. This figure is based on a DFGB 600kW diesel generator with a level III enclosure, or similar. The generator will allow the facility to operate whilst a new electricity grid connection is being laid. The aluminium shredder will be the main noise generating plant. An estimated conservative SPL of 99 db has been assumed for the aluminium shredder measured at 1m from source, based on a Sound Power Level (SWL) of 110dB. It is accepted that noise will drop by 6dB with every doubling of distance from the source. A wall comprising of single skin cladding has a Sound Reduction Index (Rw) of 24dB. However to account for any openings, doors etc., a conservative reduction of 10dB will be applied to the machinery under assessment in this instance. The equipment will as far as reasonably practicable be located as close to the centre of the building while accommodating process requirements, as to increase the attenuation distance to the receptors. This equates to approximately 8m to the east and west of the building edge, and m to the north and south of the building edge.

4 39 A background noise assessment has been undertaken in November 2016 by Globetech Laboratories Ltd attached in appendix D. Noise measurements were taken for a period of one continuous hour during both the day and at night. The measurements were taken at the development site and both of the nearest sensitive receptors in Table 6.1. A summary of the background noise levels recorded are summarised in Table 6.2 below LOCATION DISTANCE FROM DAYTIME L90 NIGHT TIME L90 EDGE OF UNIT On Site 5m Residential sections Nearest 460m of Limassol (Various) Γυμνάσιο Αγίας Βαρβάρας 480m (school) Table 6.2 Background Noise Levels The figures in table 6.2 have been used as background noise levels for the purpose of this assessment. The eastern facade of the building, which is closest to the source, has been used as the noise origin for the calculations, and in order to take a conservative approach, no additional adjustments have been taken into account for the various buildings and vegetation within the pathway that would act as a screen between the source and the receptor. Table 6.3 below summarises the calculations to determine the estimated SPL outside the facility. LOCATION SOUND SPL 1m SPL 8m CORRECTION APPROX. SPL 1m POWER LEVEL FROM SOURCE FROM SOURCE FROM FAÇADE LAEQ (dba) LAEQ (dba) (BUILDING EDGE) LAEQ (dba) LAEQ (dba) Eastern facade Table 6.3 A-weighted Sound Pressure Levels during Day Time Hours, 1m from Building Facade The distance to each receptor from the noise origin has been calculated using a mapping tool. Attenuation calculations have been performed to calculate the noise level at each of the sensitive locations identified. The results are summarised in Table 6.4. Figure 6.1 overleaf shows a curve graph used to calculate estimated attenuated noise levels at noise sensitive receptors.

5 dba Distance from source (m) Figure 6.1 Calculated Noise Levels with Attenuation during Day Time Hours LOCATION DISTANCE SPL 1m ESTIMATED DAY TIME DIFFERENCE NIGHT TIME DIFFERENCE FROM SOURCE FROM BUILDING SPL AT RECEPTOR LA90 (dba) LA90 (dba) (m) LAEQ (dba) LAEQ (dba) Residents at Sotirias Bellou Γυμνάσιο Αγίας Βαρβάρας me (school) Table 6.4 Estimated A-weighted Sound Pressure Levels at Noise Sensitive Receptors Drawing D01 in Appendix A displays day time noise levels anticipated at various noise sensitive receptors. Following a review of the data in Table 6.4, the worst-case projected noise generated by the processes attenuates considerably below recommended day time and night time background noise levels for all off site sensitive receptors. Therefore noise from the facility at these receptors would therefore be classified as unlikely to cause complaints. With regards to occupational noise control, operators within the facility will require suitable hearing protection when working in proximity to the aluminium shredder. For operators and visitors moving around the site, it is assumed that hearing protection would not be required. A full noise assessment will be undertaken for employees working within the building once the equipment is set up to determine actual noise levels.