12. Noise and Vibration

Transcription

1 12. Noise and Vibration 12.1 Executive Summary An assessment of the potential noise and vibration effects arising from the construction and operation of the Facility at Oxwellmains has been provided in accordance with the appropriate methodologies and relevant British Standards and guidance documents. The approach to the assessment undertaken and the methodologies and criteria adopted have been discussed and agreed with the local planning authority associated with the site. Cumulative construction and operation noise impacts have also been considered. Baseline information has been obtained from noise surveys carried out at the nearest noise sensitive receptors (NNSRs), which are residential properties located some distance from the Facility. These are affected by the surrounding road networks, and to a lesser extent, the existing industrial activity (including existing rail handling activities) on and around the site. Observations on-site and the survey data indicate that the ambient and background noise levels are influenced by both of these two sources. The assessment of noise and vibration effects from construction activities, including on- and off-site traffic, has indicated that no significant effects at any NNSRs are likely to arise. The assessment of the operation of the Facility has included consideration of the static, permanent process plant both contained within buildings and external and the mobile, permanent sources, such as delivery lorries and trains and vehicle movements within the site. The assessment of static sources has been based upon BS 4142 with a significant effect being deemed to occur if the Rating Level is less than the existing background noise level. The assessment of the combined noise effects from both static and mobile sources has been based upon ambient noise change with a significant effect being deemed to occur for a noise change of 3 db or greater. The assessment of noise and vibration effects from operational activities, including traffic, has indicated that significant effects would not be likely to arise at the NSRs provided that good design principles and implementation of best practice are adhered to. During construction, an appropriate Code of Construction Practice will serve to minimise any effects and ensure appropriate noise mitigation is included in the design of the Facility Introduction Viridor proposes to develop an Energy from Waste with Combined Heat and Power Facility at Oxwellmains Landfill, approximately 4.5km south-east of Dunbar town centre. The site is located within land allocated for non-hazardous landfill, which it owns and operates. The site benefits from excellent road and rail access, and is relatively remote from sensitive receptors. This Chapter provides an assessment of the potential noise and vibration effects arising from the construction and operation of the Facility. 315

2 12.3 Methodology The methodology used in this assessment has been informed by the following regulations, policy context and legislation. The methods and assessment criteria used to assess the potential effects of the proposed development. Any limitations, constraints and assumptions relating to the assessment are described in the relevant sections. The baseline conditions of the site and its environs are set out both in terms of measured noise levels as well as qualitatively. The potential direct and indirect effects arising from the construction and the operation of the completed development are addressed, with appropriate mitigation measures required to prevent, reduce or offset the effects and the significance of any the residual effects. Noise and Noise Units Noise is defined as unwanted sound. The range of audible sound is from 0 db to 140 db. The frequency response of the ear is usually taken to be about 18 Hz (number of oscillations per second) to Hz. The ear does not respond equally to different frequencies at the same level. It is more sensitive in the mid-frequency range than the lower and higher frequencies and because of this, the low and high frequency components of a sound are reduced in importance by applying a weighting (filtering) circuit to the noise measuring instrument. The weighting which is most widely used and which correlates best with subjective response to noise is the db(a) weighting. This is an internationally accepted standard for noise measurements. For variable noise sources such as traffic, a difference of 3 db is just distinguishable. In addition, a doubling of a noise source would increase the overall noise by 3 db. For example, if one item of machinery results in noise levels of 30 db at 10 m, then two identical items of machinery adjacent to one another would result in noise levels of 33 db at 10 m. The "loudness" of a noise is a purely subjective parameter but it is generally accepted that an increase/decrease of 10 db corresponds to a doubling/halving in perceived loudness. External noise levels are rarely steady but rise and fall according to activities within an area. In an attempt to produce a figure that relates this variable noise level to subjective response, a number of noise metrics have been developed. These include: L Aeq noise level this is the "equivalent continuous A-weighted sound pressure level, in decibels" and is defined in BS 7445 as the "value of the A-weighted sound pressure level of a continuous, steady sound that, within a specified time interval, T, has the same mean square sound pressure as a sound under consideration whose level varies with time". It is a unit commonly used to describe community response plus, construction noise and noise from industrial premises and is the most suitable unit for the description of other forms of environmental noise. In more straightforward terms, it is a measure of energy within the varying noise. L A90 noise level this is the noise level that is exceeded for 90% of the measurement period and gives an indication of the noise level during quieter periods. It is often referred to as the background noise level and is used in the assessment of disturbance from industrial noise. L A10 noise level this is the noise level that is exceeded for 10% of the measurement period and gives an indication of the noisier levels. It is a unit that has been used over many years for the measurement and assessment of road traffic noise. 316

3 Vibration and Vibration Units Whereas noise is primarily received through the air and perceived by the auditory senses, vibration is lower frequency phenomenon, which is primarily received through the ground or through structures and is perceived by the body as movement. This movement can be felt as sudden shocks or more gentle displacement dependent upon the frequencies and magnitude of the source. Ground-borne vibration from construction sources, such as piling, can be a source of concern for occupants of buildings in the vicinity. The concern can be that the building may suffer some form of cosmetic or structural damage or that ground settlement may arise that could subsequently lead to damage. Research associated with BS 7385, Part 1, concerned with vibration-induced building damage, found that although a large number of case histories were assembled, very few cases of vibration-induced damage were found. However, structural vibration in buildings can be detected by the occupants and can affect them in many ways: their quality of life can be reduced, as also can their working efficiency, although, there is little evidence that whole-body vibration directly affects cognitive processes. It should be noted that there is a major difference between the sensitivity of people feeling vibration and the onset of levels of vibration that damage a structure. Vibration Dose Value (VDV) The effect of structure-borne vibration affecting people inside buildings is assessed by determining their vibration dose. Present knowledge indicates that this is best evaluated with the VDV, as promoted through BS VDV defines a relationship that yields a consistent assessment of intermittent, occasional and impulsive vibration, as well as continuous input, and correlates well with subjective response. The means by which people perceive building vibration depends upon various factors, including the vibration frequency and direction. The VDV is given by the fourth root of the time integral of the fourth power of the acceleration after it has been frequency weighted. Peak particle velocity (PPV) is defined as the maximum instantaneous velocity of a particle at a point during a given time interval, and has been found to be the best single descriptor for correlating with case history data on the occurrence of vibrationinduced damage to buildings and structures. Impact Assessment Construction Noise levels due to the construction phase have been predicted using WS Atkins NoiseMap 2000 noise modelling software, implementing the methodology contained within BS Source terms have been obtained from the DERFA 2005 update to BS 5228 based on plant considered to be typical for the works that would be required. BS 5228 BS 5228: Noise and vibration control on construction and open sites, Parts 1, 2 and 4 provide guidance on the control of noise from construction and open sites. Part 4 of the standard deals specifically with noise and vibration generated by piling operations. This Standard, in its various parts, has been adopted under s. 71 of CoPA (Codes of Practice for minimising noise). 317

4 Part 1, Code of practice for basic information and procedures for noise and vibration control, gives recommendations for basic methods of noise and vibration control relating to construction and open sites where work activities/operations generate significant noise and/or vibration levels. It includes sections on: legislative background; community relations; training; occupational noise effects; neighbourhood nuisance; project supervision; and control of noise and vibration. However, annexes include: a list of EC and UK legislation; noise sources, remedies and their effectiveness (mitigation options); guide to sound level data on site equipment and site activities (source terms that are used for modelling); estimating noise from sites (calculation procedures which form the basis of the modelling packages); and noise monitoring. BS 5228 does not suggest construction noise limits. The following limit will be adopted, which is based upon criteria adopted for other major infrastructure projects together with current best practice. TABLE 12.1 THRESHOLD OF SIGNIFICANCE FOR CONSTRUCTION NOISE Significant impact occurs if: Total Noise Level During Construction, db L Aeq,12hr (Baseline Ambient Noise Level + Noise Level from Construction Alone) >Baseline Ambient Noise Level, L Aeq,12hr + 5 db Part 2, Guide to noise and vibration control legislation for construction and demolition including road construction and maintenance, provides further detail on the legislation applicable to construction and related aspects. Part 4, Code of practice for noise and vibration control applicable to piling operations, provides specific advice and information on legislation, source terms, prediction, monitoring etc of noise and vibration from piling operations. The guidance provided within BS 5228 on the response of buildings and structures to construction vibration is provided in Table 12.2 and has been adopted as the thresholds of significant impact for construction vibration. TABLE 12.2 BS 5228 GUIDANCE ON THE RESPONSE OF BUILDINGS AND STRUCTURES TO CONSTRUCTION VIBRATION Category of Building (residential property and Threshold of Significant Impacts Peak Particle Velocity (PPV) At Building Foundation similar) Continuous Vibration Intermittent Vibration Standard buildings 5 mm/s 10 mm/s Listed and potentially 3 mm/s 5 mm/s vulnerable buildings BS 6472 BS 6472: Guide to Evaluation of human exposure to vibration in buildings (1 Hz to 80 Hz) provides guidance on human response to vibration experienced in buildings. The standard includes weighting curves related to human response are provided. However, it should be noted that the Standard is currently being revised. BS 6472 provides the following guidance on the human response to vibration. 318

5 TABLE 12.3 BS 6472 GUIDANCE ON THE HUMAN RESPONSE VIBRATION Place Low probability of adverse comment Adverse comment possible Adverse comment probable Residential buildings 16 hr 0.2 to to to 1.6 daytime Residential buildings 8 hr night-time Office buildings 16 hr daytime Industrial buildings 16 hr daytime The levels contained in Table 12.3 are appropriate for the human response to permanent sources such as railways or industrial sites. It is considered that the appropriate thresholds of significance for construction vibration are contained in the third column Adverse comment probable. This is because construction vibration is a temporary and short-term impact and, with appropriate community liaison, a significantly higher vibration dose will be tolerated than for a permanent source. Operation Planning Policy Guidance 24 (PPG 24) Planning and Noise and BS Method for Rating Industrial Noise Affecting Mixed Residential and Industrial Areas, PPG 24 is the principal noise guidance in the UK and cites the use of British Standard 4142 to assess noise from industrial and commercial premises as it affects people residing in a building. Paragraph 19 of Annex 3 of PPG 24 states the following: The likelihood of complaints about noise from industrial development can be assessed, where the Standard is appropriate, using guidance in BS 4142: Tonal or impulsive characteristics of the noise are taken into account by the 'rating level' defined in BS This 'rating level' should be used when stipulating the level of noise than can be permitted. The likelihood of complaints is indicated by the difference between the noise from the new development (expressed in terms of the rating level) and the existing background noise. The Standard states that: 'A difference of around 10 db or higher indicates that complaints are likely. A difference of around 5 db is of marginal significance.' Since background noise levels vary throughout a 24 hour period it has been necessary to assess the acceptability of noise levels for separate periods (e.g. day and night) chosen to suit the hours of operation of the project. Similar considerations apply to developments that would emit significant noise at the weekend as well as during the week. In addition, general guidance on acceptable noise levels within buildings can be found in BS 8233: The method is based upon a comparison between the Specific Noise Level, corrected if appropriate to become the Rating Level of the noise from the specific source being considered and the background noise level (measured as an L A90 ), in the absence of the specific source. The noise level from the specific source (Specific Noise Level) is increased by 5 db, if the source has any distinctive characteristics (tones or impulses such as whines, hums or bangs), or if it is irregular enough to attract attention and becomes known as the Rating Level. As stated above, the standard states that if the Rating Level of the noise exceeds the background noise level by around 10 db or more, complaints are "likely". An increase of 5 db is deemed to be of "marginal significance" whilst a difference of 319

6 minus 10 db or more indicates that "complaints are unlikely". These descriptions are summarised in Table 12.4 below. TABLE 12.4 BS 4142 SIGNIFICANCE CRITERIA BS 4142 Assessment Level, BS 4142 Semantic (as described in the Standard) db(a) (Rating Level relative to Background Level) < -10 "If the rating level is more than 10 db below the measured background level then this is a positive indication that complaints are unlikely" -10 to +5 No BS description but the more negative the difference, the less the likelihood of complaints +5 "A difference of around +5 db is of marginal significance" +5 to +10 No BS description but the more positive the difference, the greater the likelihood of complaints > +10 "A difference of around 10 db or more indicates that complaints are likely" In situations where the L A90 background noise level at night is low (less than 30 db) and the Rating Level is low (less than 35 db), the standard states that the rating method of BS 4142 is not applicable. In these circumstances, it is standard practice to assess the noise effect by considering sleep disturbance criteria and other aspects such as noise change. Noise Change In addition to the above, consideration has also been given to the noise change that would occur in the area as a result of the introduction of the Facility. Given that noise from the plant would be constant in character, it would raise the existing background level and an increase of 3 db or more is assessed as significant. Consideration has also been given to the effect on the ambient noise level (L Aeq ), with again any change greater than 3 db being considered significant. The following semantic scale has been adopted to assess the significance of the effects of noise change associated with the cumulative noise emissions from both static and mobile noise sources associated with the operation of the Facility and of delivery HGVs on local roads. TABLE 12.5 SEMANTIC SCALE FOR DESCRIBING NOISE CHANGE THRESHOLDS OF SIGNIFICANCE (PERMANENT SOURCES AND OPERATIONAL TRAFFIC) Noise Change, L Aeq,T (db) Scale Rating Decrease of more than 3 db Significant decrease Significant Positive Effect Less than 3 db change No Significant change No Effect Increase of 3 5 db Minor Increase Increase of 6 10 db Moderate Increase Significant Adverse Effect Increase of more than 11 db Major Increase Road Traffic Noise The main method of calculating road noise is defined in the Calculation of Road Traffic Noise (CRTN). This method of predicting noise at a reception point from a road scheme considers effects from the carriageway to the reception point taking into account: distance attenuation; screening of the source line; and site layout features, including reflections from buildings and facades. 320

7 For this project, the CRTN methodology has been used in a simplified form to predict changes in road traffic noise levels along route sections, i.e. calculations have not been carried out at individual receptors but for sections of road subject to the same changes in traffic flow. On this basis, all receptors along a route section will be subject to the same change in noise level. Two scenarios have been considered: traffic changes during construction and during operation. The assessment then considers the change in the noise level without and with the additional traffic. For construction traffic, it is considered that a greater impact would be tolerated, as the source is only temporary. Therefore, the following semantic scale has been adopted to describe temporary noise change: TABLE 12.6 SEMANTIC SCALE FOR DESCRIBING NOISE CHANGE THRESHOLDS OF SIGNIFICANCE (NON-PERMANENT CONSTRUCTION TRAFFIC) Noise Change, L Aeq,T (db) Scale Rating Decrease of more than 6 db Significant decrease Significant Positive Effect Less than 6 db change No Significant change No Effect Increase of 6 10 db Minor Increase Increase of db Moderate Increase Significant Adverse Effect Increase of more than 21 db Major Increase Note: T is the period of construction activity Operational Railway Noise The main method of calculating railway noise is defined in the Calculation of Railway Noise (CRN). Similarly to the method for road noise, the method accounts for flows, distances and screening. Again, a simplified assessment method has been adopted, to predict noise change, based on change in flows and train type. Any railway noise change has been assessed against the same criteria as for operational road noise, as given in Table An increase or decrease of less than 3 db would not be considered a significant change, and no effect would be observed. Vibration The operation of the Facility is not predicted to produce significant levels of vibration at any location. Operational vibration effects are therefore unlikely and a quantitative assessment is not required Baseline Assessment Site and Area Description The proposed location of the Facility is within the Oxwellmains Landfill Site, which is owned and operated by Viridor Waste Management Ltd. The Oxwellmains site currently operates as a landfill, adjacent to a quarry and Cement Works operated by Lafarge and these activities would continue once the Facility became operational. The site lies between the A1 and the railway, south of Dunbar. The surrounding area is predominantly rural, with coastal parkland to the north. The Facility site occupies an area of land designated for use as landfill. The area on which the Facility is proposed comprises an area of the former quarry infilled with quarry spoil, not yet utilised as landfill. 321

8 The site is situated in a generally semi-rural area, with agricultural land dominating the surrounding landscape. However, the location of the site within a landfill, with Lafarge Cement Works and Torness Power Station in the surrounding 5 km gives the site an industrial background. The site is remote from areas of residential development. The following residential properties/areas have been identified, the nearest being approximately 500 m from the Facility main building. Baseline Assessment Survey Locations and Noise Environment The noise assessments require a comparison between the existing daytime and night-time noise environments at the nearest noise sensitive receptors (NNSRs) and the future noise levels that would be expected to occur, at those locations, should the Facility be constructed. Existing noise levels were determined by a field study. The field study comprised two, long-term unattended noise survey at separate locations in the area. The noise monitors were installed at locations that were representative of the NNSRs to the Facility, which are habitable dwellings to the south and east of the site. The survey locations are shown in Figure The long-term survey logged measurements over a period of 7 days. All surveys were undertaken at free-field locations with the microphone at a height of 1.5 m above ground level. The instrumentation was calibrated both prior to and immediately following the surveys to ensure that no significant drift had occurred over the survey period. All instrumentation was within the manufacturers periods of calibration, as specified in BS BS 4142 requires a representative background noise level to be adopted for the assessment. There is no government or BS guidance that states what is considered to constitute representative and the night-time period can be subject to a wide variation as it includes the evening/night and night/morning shoulder periods. One approach that is commonly adopted, and has been adopted for this project, is to use the average L A90 between and hours for the daytime period and the average between and hours for the night-time period. The background noise was measured in two locations, to establish the existing noise climate within the vicinity of the proposed site. Long-term 4 Easter Meikle Pinkerton The survey was undertaken at the end of the property s area of hardstanding, with a restricted view towards the development site at approximately 500 m distance. The microphone was set at a height of 1.5 m above local ground level, in a free-field position. The survey was undertaken from 13:33 hours 20 July to 13:41 hours on 27 July Figure 12.1 shows where the survey equipment was located. The instrumentation used consisted of a Rion NL-31 Sound Level Meters and a Brüel & Kjær 4231 Calibrator. The SLMs were set-up to record the 1-second L Aeq noise metric. All instrumentation was calibrated both prior to and immediately following the survey, to ensure that no significant drift had occurred over the survey period. All instrumentation was within the manufacturer s periods of calibration, as specified in BS :

9 Background noise at the location was dominated by noise from road traffic on the A1, with noise from the Cement Works possibly contributing during the quietest periods on the road. The results from the long-term survey are provided in Table 12.7 below. Long-term Broxmouth Cottage The second survey was undertaken in the garden of Broxmouth Cottage, approximately 1600 m north-west from the proposed site. The proposed development site and surrounding was obscured from site. The microphone was set at a height of 1.5 m above local ground level, in a free-field position. The survey was undertaken from 12:37 hours 20 July to 13:27 hours on 27 July Figure 12.1 shows where the survey equipment was located. The instrumentation used consisted of a Rion NL-32 Sound Level Meters and a Brüel & Kjær The SLMs were set-up to record the 1-second L Aeq noise metrics over the measurement period. Additionally, the Rion sound recording module recorded events over 78 db(a) and audio snap-shots at 15-minute intervals. These indicated that the sources of maximum noise levels tended to be a mix of events local to the meter (dogs barking and birdsong) and more distant aircraft activity, specifically military jet aircraft. Ambient noise was characterised by vehicle noise on the A1087 and A1 beyond, and by environmental noise. All instrumentation was calibrated both prior to and immediately following the survey, to ensure that no significant drift had occurred over the survey period. All instrumentation was within the manufacturer s periods of calibration, as specified in BS :2003. While on site, further observations of the noise character of the site were made: Background noise at the location was dominated by noise from road traffic on the A1 and A1087, with noise from the adjacent Lafarge quarry and cement Works contributing during the quietest periods on the roads. Reversing bleepers were occasionally audible, presumed to be from the quarry or landfill sites. The results from the long-term survey are provided in Table TABLE 12.7 LONG-TERM NOISE SURVEY RESULTS 4 Easter Meikle Pinkerton Broxmouth Cottage L Aeq L Amax L A10 L A90 L Aeq L Amax L A10 L A90 Day Max :00 Min :00 Avg Workday Max :00 Min :00 1 Avg Night Max :00 Min :00 Avg Note 1 : 07:00 19:00 Monday to Friday, 07:00 13:00 Saturday, no Sunday working 12.5 Impact Assessment Construction Effects Noise from General Activities It is anticipated that the construction period would be approximately three years excluding site clearance. Normal working hours on site would be between and hours Monday to Friday, and 07:00 to 13:00 hours Saturday, with some 323

10 flexibility for further weekend working when required. During the concrete pours for the foundations, it may be necessary to work 24-hours a day, although only for a limited duration. During commissioning, the plant would become operational on a 24- hour basis. Four representative periods during the construction phase have been assessed quantitatively: site preparation/demolition of the existing buildings; ground excavations, including piling; building construction and equipment installation; and possible night-time concrete pours. Piling during civil works is likely to be undertaken using a driven-hammer technique. The assessment has considered hydraulic hammer rig, to give assessment of a worst-case basis. Using the WS Atkins NoiseMap 2000 software, predicted noise levels have been calculated to the first floors of 16 residential properties representative of the surrounding area. The results of the construction assessments are provided in Table Construction works would be undertaken in accordance with the Code of Construction Practice, which will be developed for the works. The code will establish construction methods and techniques so as to reduce noise in accordance with best practice. TABLE 12.8 PREDICTED NOISE LEVELS DURING CONSTRUCTION ACTIVITIES Approximate distance from site/m Opening site, commencement of the works/db Substructure works, foundations, floors/db Superstructure/ Walls Roof/dB Night-time concrete pour/db Commissioning tests, maximum levels/db 1 Easter Meikle Pinkerton Farm Easter Meikle Pinkerton Farm Easter Meikle Pinkerton Easter Meikle Pinkerton Easter Meikle Pinkerton Easter Meikle Pinkerton West Meikle Pinkerton Farm Meikle Pinkerton West Meikle Pinkerton Cottages North Lodge Cottage Broxmouth Cottage Broxburn PC/Catcraig Skateraw Little Pinkerton Thurston Manor The results of the construction noise assessment indicate predicted noise levels would vary, depending upon the activities on the site. The predicted temporary change in noise level would be most likely to be noticeable to the residents closest to the site, primarily Easter Meikle Pinkerton Farm and cottages, which would 324

11 experience a maximum 12-hour noise level of around 47 db L Aeq,12hr from the piling works. This is approximately equal to the average existing daytime ambient level of 50 db L Aeq,12hr. and below the + 5 db threshold of 55 db at which construction noise would result in an impact. With reference to Table 13.1, significant effects are not expected to occur. Although construction activities may be noticeable at some properties, the magnitude of the noise is not such as to result in significant impact. Other daytime construction activities, of site set-up and superstructure works are predicted to be between 3 and 8 db quieter than the piling activities, and similarly would not result in significant noise impact. During the occasional night-time concrete pours, a maximum level of 37 db L Aeq,8hr is predicted. Again, this is below the existing night-time ambient level of 41 db L Aeq,8hr, and below the threshold at which impact might occur, at 46 db. No further mitigation in addition to the working practices described within the draft Code of Construction Practice (CoCP) would be required. However, best practice will be adopted as appropriate, to further minimise noise emissions from the construction of the Facility. Vibration It is considered that during construction, driven piling or vibratory piling activities would have the potential to give rise to significant vibration effects. Other piling techniques, such as bored or augured piles would be unlikely to give rise to significant vibration levels. Significant vibration effects due to HGVs are unlikely provided that the haul roads are well maintained, so as to not contain significant pot holes or ruts. The construction vibration assessment determines the distance at which effects would be significant for a typical impact piling rig, based upon the thresholds of significance provided in Table 12.2 and Table Relatively low hammer energies are used for sheet piling to prevent the pile from bending. It is considered that hammer energies could be in the order or 5 to 15 kj, in which case a significant effect would not be expected to occur provided that the piling was undertaken at least 10 to 16 m from the nearest building. All proposed structures on site are at least 400 m from the nearest houses. Therefore, a significant vibration effect is unlikely to occur during the construction phase of the project and no mitigation would be required. The cumulative effects of vibration, should piling coincide with vibration generating activities at the adjoining quarry would not be significantly greater than that arising from the quarry alone. Noise from Construction Traffic The assessment has considered the noise effects of all construction traffic accessing the site from the A1 via the A1087 and site access road. The results of the construction noise assessment indicate that a significant noise effect would not occur as a result of construction traffic using local roads. The maximum noise effect is predicted to occur during the PM peak hour, on the Oxwellmains road, between the site access and A1087 roads. A maximum increase 325

12 in noise from this link of 1.3 db is predicted for the worst hour. This increase would not be considered a significant noise effect, and furthermore, as no residential properties lie adjacent to this link, the effect is further reduced. The greatest noise increase which might directly affect residential areas occurs on the A1 west of the A1087 junction, which would experience a maximum noise increase of 0.4 db; this increase, again is not considered to be a significant noise effect. Commissioning Some activities associated with the commissioning of the Facility are likely to give rise to high noise levels. During the commissioning and testing of the Facility it would be necessary to discharge high-pressure steam to the atmosphere. Steam blowing of pipe-work is unavoidably noisy and generally lasts approximately 20 minutes per blow, occurring several times per day for several days. Testing of safety valves would also be noisy but be of short duration and would occur from time to time during the commissioning. The high noise levels associated with this activity would be reduced through the inclusion of silencers on the vents. Maximum noise levels of 61 db are predicted at Easter Meikle Pinkerton Farm, with lesser levels at residential properties beyond. Given that these events would be of relatively short duration and of limited number, it is considered that the impact would be minor adverse. Steam blows and testing of safety valves would, when practicable, be undertaken during normal daytime working hours and, where practicable, using silencers to minimise the noise emissions. It is considered that appropriate community liaison that would inform local residents of the proposed testing schedule is the only effective additional measure that would be practicable for these sources during this phase of the commissioning. This would be undertaken throughout the construction phase, as set out in Code of Construction Practice. Operational Effects Noise levels arising from the operation of the Facility have been predicted using WS Atkins NoiseMap 2000 noise modelling software, implementing the methodology contained within BS 5228 and Concawe. Source terms have been obtained from Keppel Seghers, the technology advisor for the project, BS 5228 Part 1 and the DEFRA update to BS 5228 for items of mobile plant. Sound attenuation measures would be incorporated into the design of the project to ensure that noise levels in the external and internal general plant areas do not exceed 85 db(a) at 1 m distance in places where staying due to maintenance or operation is necessary (measured at free field conditions). Exceptions are listed below. safety valves 120 db(a) at 1 m distance; start up vent valves 100 db(a) at 1 m distance; hydraulic group (in specific enclosure); and impulse noise sources (such as mechanical rapping system, air shocks and pneumatic hammers). Keppel Seghers has also indicated that: the total sound pressure level from all apparatuses combined will not exceed 100 db(a) at 1 m distance; the sound 326

13 pressure level outside buildings will not exceed 65 db(a) at 5 m distance, except for the air-cooled condenser; and the sound pressure level at 200 m from the site enclosure will not exceed 43 db(a). The operational effects of static sources have been assessed using the methodology contained within BS In addition, consideration has also been given to the ambient noise change that would occur as a result of both static and mobile sources associated with the introduction of the Facility. For this site, the baseline background noise levels at NNSRs are influenced by noise from the A1 road, which runs adjacent to the site, separating the site from some areas of NNSR. On this basis, it is considered that the design target should be that there is no significant increase in existing background noise level at NNSRs. This requires that the Rating Level from the Facility should be below the existing background noise level and has been adopted as the threshold of significance for the BS 4142 assessment. The operation of the Facility will result in noise emissions from various sources within the Facility building, and through doors and vents in the structure. The technology providers, Keppel Seghers has indicated that the cumulative effect of all these sources will result in a noise level of no more than 43 db(a) at 200 metres distance. The resulting noise levels at the nearest areas of noise sensitive receptors are listed below. TABLE 12.9 PREDICTED NOISE LEVELS DURING OPERATION ACTIVITIES Operation Approximate distance from site/m Normal Operation/dB Emergency operation or test \ db Start-up steam vent \ db 1 Easter Meikle Pinkerton Farm Easter Meikle Pinkerton Farm Easter Meikle Pinkerton Easter Meikle Pinkerton Easter Meikle Pinkerton Easter Meikle Pinkerton West Meikle Pinkerton Farm Meikle Pinkerton West Meikle Pinkerton Cottages North Lodge Cottage Broxmouth Cottage Broxburn PC/Catcraig Skateraw Little Pinkerton Thurston Manor Maximum predicted noise levels of 30 db L Aeq,1hr are predicted to occur at Easter Meikle Pinkerton Farm, with lesser levels predicted at other NSRs. BS 4142 Assessment The results of the BS 4142 assessment indicate that the design criterion would be satisfied and that significant adverse noise effects would not be expected to occur as a result of the development during the daytime or night-time at any of the NNSRs. 327

14 To ensure a robust assessment of the possible impact from the Facility, a +5 db rating correction has been added to the predicted noise generated by the site, in accordance with BS The design of the Facility will endeavour to reduce any tonal, impulsive or otherwise vexatious character. However, given the subjective nature of this correction, the rating correction is included. The greatest effect has been predicted to occur at Easter Meikle Pinkerton Farm, during the night-time. At this location, the Rating Level of 35 db has been predicted, and would occur during both the day and night periods while the Facility is operating. This is less than 5 db above the minimum measured L A90 background level of 31 db L A90, and 3 db below the average night-time background noise level. An assessment under BS 4142 indicates that this level of noise would be of less than marginal significance. At Broxmouth Cottage, a rating level of 26 db is predicted. Again, this is less than 5 db above the minimum measured L A90 background level of 27 db L A90, and 13 db below the average night-time background noise level. An assessment under BS 4142 indicates that this level of noise would be of less than marginal significance. Other NNSRs in the area would experience a similar or lesser effect. It is considered that operational noise from the Facility would not be significant. Noise Change Assessment The results of the assessment of both static and mobile noise sources indicate that a significant adverse noise change would not be expected to occur at any of the NNSRs during the daytime or night-time at any of the NNSRs. The greatest effect has been predicted to occur at Easter Meikle Pinkerton Farm, during the night-time. At this location, the predicted night-time noise change is 0.3 db compared against the average ambient level. Compared against the minimum ambient measurement, an increase of 1.5 db is predicted. It is considered that this would not be significant, as the increase would not be readily perceptible. Start-up and Emergency Steam Venting Steam is vented during the firing up of the Facility. The higher noise levels associated with this activity would be reduced through the inclusion of silencers on the vents. As it is intended that the Facility run continuously, start-up activities would be infrequent. During start-up, maximum noise levels of 41 db are predicted at Easter Meikle Pinkerton Farm, with lesser levels at residential properties beyond. Given that these events would be of relatively short duration and of limited number, it is considered that the impact would be minor. Under exceptional emergency conditions, it may be necessary to rapidly release steam to atmosphere. Maximum noise levels of 61 db are predicted at Easter Meikle Pinkerton Farm, with lesser levels at residential properties beyond. Given the emergency nature of the event, the venting could occur any time during the day or night. Given that these events would be of relatively short duration and of rare occurrence, it is considered that the impact would be minor adverse significance. 328

15 Noise from Operational Traffic As and when the Facility is fully operational, it will receive 300,000 tonnes per annum. This will be made up as follows: 150,000 tonnes residual MSW; and 150,000 tonnes residual commercial and industrial waste. Additionally, the landfill may receive approximately 100,000 per annum of material not suitable for the Facility, giving a grand total into the site of circa 400,000 tonnes. Up to 185,000 of the 400,000 tonnes may arrive by rail. As a worst case assessment, the impact from 400,000 tonnes by road and 185,000 tonnes by rail have been assessed. Currently waste is brought to the operational landfill site via both road (transported via the A1) and rail. From this, the Facility will produce 91,333 tonnes of bottom ash, of which 66,333 tonnes will be exported from the site by road, for use in secondary aggregates. Under the proposed scheme, up to two trains per day will visit the site, using the main line between Edinburgh and Newcastle, which carries typically 100 passenger trains per day. A worst case assessment indicates that noise from the additional freight would increase the daytime ambient noise levels by no more than 1.5 db; the increase in train movements will therefore not be significant. The Transport Assessment has provided the predicted future traffic flows for 2011 and 2026 with and without the project and for the cumulative situation with the project with other committed development. Increases in daily traffic flow are predicted to result in an increase in the noise associated with any road link of less than 1 db. This would not be a significant change. The results of the traffic noise assessment indicate that a significant noise effect would not occur as a result of increased traffic flows on local roads Mitigation Measures Adopted as Part of the Project The project would be designed to comply with current Health and Safety Executive requirements as provided in the Control of Noise at Work Regulations Sound attenuation measures would be incorporated into the design of the project to ensure that noise levels in the external and internal general plant areas do not exceed 85 db(a) at 1 m distance in places where staying due to maintenance or operation is necessary (measured at free field conditions). Valves and vents are to be fitted with acoustic treatment to reduce the high noise levels associated with these activities. Good design and best practice have served to reduce noise from the Facility at source, thus reducing the need for additional mitigation. An appropriate Code of Construction Practice will ensure that construction noise is limited to an acceptable level. 329

16 Further Mitigation Options No further mitigation options are considered necessary as a result of this assessment. However, the ongoing development process for the proposal will seek to identify areas where noise can be further reduced, in line with best practice Statement of Significance Summary of Effects Overall, the construction and operation of the Facility will have little effect on the existing noise environment. Those activities which do result in an effect of minor significance would be temporary in nature, and would be unlikely to result in any reduction in aural amenity to residents in the surrounding areas. Table provides a summary of the effects associated with the construction and operational phases of the project. TABLE SUMMARY OF EFFECTS Effect Construction Temporary Increase in Daytime None Ambient Noise Levels Temporary Increase in Night-time None Ambient Noise Levels Likelihood of Complaints due to N/A Operational Noise Vibration effects due to None construction or operation Permanent Increase in Daytime N/A Ambient Noise Levels Permanent Increase in Night-time N/A Ambient Noise Levels Noise Change due to Increased None Traffic on Local Road/Rail Significance of Effects Operation Minor, during commissioning/emergency steam vent Minor, during emergency steam vent Neutral None None None None 330

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