A465 Heads of the Valleys Dualling Sections 5 and 6: Dowlais Top to Hirwaun PROOF OF EVIDENCE: Noise and Vibration Document WG 1.8.1 By: Andrew Clarke BSc MIOA March 2018
PROOF OF EVIDENCE: Noise and Vibration CONTENTS Page No. 1 Personal Statement... 1 2 Scope of This Proof... 3 3 Baseline Conditions... 4 4 Assessment Methodology... 6 5 Assessment Results Environmental Statement... 11 6 Assessment Results ES Supplement... 12 7 Mitigation Strategy... 25 8 Conclusions... 29 9 Declaration... 31
1 Personal Statement 1.1 My name is Andrew Stephen Clarke. I am employed by Jacobs UK Ltd as a Technical Director within the Acoustics team and have over 20 years of experience working in Acoustics consultancy. 1.2 I have a Bachelor of Science (Hons) degree in Biology and have held membership of the Institute of Acoustics since 2000, initially as an Associate Member (AMIOA) and more recently as a Member (MIOA). 1.3 I have been the Noise and Vibration lead for the assessment of over 15 highways schemes in the UK and have given expert witness testimony for National Infrastructure Planning (NIP) Hearings and Public Inquiries (PIs). Recent highway schemes for which I was the Noise and Vibration lead include the Congleton Link Road, Preston Western Distributor, Poynton Bypass, M6 J16 to 19 Smart Motorway Programme and Penwortham Bypass. 1.4 For this scheme, I was first involved in June 2017 shortly before the Environmental Statement (ES) (DD 2.2.12) was published. I have since been responsible for overseeing the updated assessment work undertaken, evaluating noise mitigation options and producing the ES Supplement (DD 2.4.1) Noise and Vibration chapter produced for the scheme in February 2018. 1.5 I am a member of the project team who are responsible for the delivery of the A465 Sections 5 and 6 Dowlais Top to Hirwaun scheme. Although the noise modelling and analysis work has been carried out by a team of specialists under my direction, I take ownership of the results described below and the opinions given are my own. Andrew Stephen Clarke / March 2018 1 of 31
1.6 I am required by the Code of Conduct of the institute of Acoustics (IOA) to uphold the dignity and reputation of the profession and of the Institute and of its members and officers, safeguard the public interest in matters of safety, health and the environment, exercise professional skill and judgement to the best of my ability and discharge my professional responsibilities with integrity, honesty and diligence. This includes giving evidence in a fair and impartial manner. Andrew Stephen Clarke / March 2018 2 of 31
2 Scope of This Proof 2.1 This Proof of Evidence addresses Noise and Vibration relating to the A465 scheme proposals. 2.2 An initial assessment of the scheme was undertaken in 2016/2017 and reported in the ES (DD 2.2.12) published in July 2017. Following updates to traffic data, the scheme was reassessed and reported in the ES Supplement (DD 2.4.1), published in February 2018. This ES Supplement supersedes the construction and operational assessments presented in the ES. An Updated Operational Assessment has recently been undertaken, to include the small design changes that have occurred since the original assessment work, including those detailed in the Supplementary Orders. The results of this Updated Operational Assessment will be provided in a Future Supplement to this Proof of Evidence. 2.3 This Proof focuses on the assessment within the more recent ES Supplement (DD 2.4.1). It sets out the current baseline and noise issues, the methodology and guidance that has been used for the noise and vibration assessment, the findings from the assessment, the mitigation strategy that has been used and the residual impacts. Andrew Stephen Clarke / March 2018 3 of 31
3 Baseline Conditions 3.1 For the purposes of the noise assessment, the baseline scenario is represented by the predicted ambient noise levels in the opening year, without the proposed scheme in place (Do Minimum 2022 scenario). This approach follows the guidance within the Design Manual for Roads and Bridges (DMRB), Volume 11, Section 3, Part 7 Noise and Vibration, HD 213/11 Revision 1 (HD 213/11) (DD 14.2.5). 3.2 The guidance in HD 213/11 (DD 14.2.5) advises the use of the Calculation of Road Traffic Noise (CRTN) (DD 14.3.1) prediction method. This methodology provides predicted noise levels across the entire study area under consistent conditions (i.e. not subject to traffic flow variations, or meteorological variations that would affect propagation scenarios). The CRTN procedure assumes a moderately adverse wind scenario; that is with the wind blowing from the source to the receiver (as described in CRTN (DD 14.3.1) paragraph 4). 3.3 The noise environment in much of the study area is generally dominated by traffic noise and therefore predictable using the road traffic noise model. This method of using the traffic model to quantify baseline noise levels is standard practice for highway noise assessment. 3.4 Baseline noise monitoring was undertaken during January and February 2016 at eleven locations considered representative of communities along the scheme. The data was used predominantly to provide baseline noise levels for use in the construction assessment, but also to enable comparison with the predicted Do- Minimum 2022 noise levels. Andrew Stephen Clarke / March 2018 4 of 31
3.5 The baseline noise monitoring locations chosen included some of the nearest properties to the proposed A465, and therefore, the likely worst affected by the proposed scheme. Long term noise monitoring (approximately 1 week at each location), was carried out at a total of seven locations. The long term noise surveys were supplemented with short term attended monitoring (following the CRTN shortened measurement procedure) at four locations, where access could not be obtained or the garden areas were not considered secure. The proposed noise monitoring locations were discussed with an Environmental Health Officer (EHO) at Merthyr Tydfil County Borough Council (MTCBC) and a Pollution and Public Health Manager at Rhondda Cynon Taf County Borough Council (RCTCBC) in advance of the survey. Full details of the noise monitoring undertaken and results obtained are provided in Section 14.6 and Appendix 14C of the ES Supplement (DD 2.4.1). 3.6 The current noise environment is generally dominated by road traffic noise, caused by traffic on the A465 and the surrounding road network. Noise levels adjacent to the existing A465 carriageway vary from around 50 db LA10,18h to around 80 db LA10,18h, according to the distance between the road and the façade of the property and whether or not there are other properties or other screening structures between them and the road. 3.7 A single Noise Action Plan Priority Area (NAPPA), number 362, is located within the study area, to the south of the proposed scheme in Dowlais Top. Noise levels approaching 80 db LA10,18h are seen at properties situated within the NAPPA, as illustrated by the ST4 noise monitoring location results provided in Table 14.8 of the ES Supplement (DD 2.4.1). Andrew Stephen Clarke / March 2018 5 of 31
4 Assessment Methodology 4.1 An assessment of noise and vibration for the proposed scheme has been undertaken in accordance with national guidance, including HD 213/11 (DD 14.2.5). The assessment of noise and vibration impacts at nearby noise sensitive receptors has followed the Detailed Assessment methodology outlined in HD 213/11 (DD 14.2.5). 4.2 For construction noise, consideration was given to the likely worstcase phases of construction works. Using the indicative construction activities and plant detailed in Appendix 14E of the ES (DD 2.2.12), construction noise levels have been predicted at representative receptors located in close proximity to the works. Construction noise levels at nearby sensitive receptors were calculated using the CadnaA noise modelling package, which incorporated the prediction methodologies contained in BS 5228-1: 2009 + A1: 2014 - Code of practice for noise and vibration control on construction and open sites, part 1: Noise (BS 5228-1) (DD 14.2.3). 4.3 The numbers of dwellings and other sensitive receptors (OSRs) where construction noise levels are expected to be close to or exceed the relevant threshold values from BS 5228-1 (DD 14.2.3) have been estimated. The significance of the impact associated with these exceedances has been classified according to the following categories: potential minor impacts are judged to have occurred where the construction noise levels are within a range of 0-5 db below the relevant threshold; Andrew Stephen Clarke / March 2018 6 of 31
potential moderate impacts are judged to have occurred where the construction noise levels are between 0-5 db above the relevant threshold; and potential major impacts are judged to have occurred where the construction noise levels are greater than 5 db above the relevant threshold. 4.4 In determining whether a significant effect would occur, guidance within BS 5228-1 (DD 14.2.3) advises that consideration should be given to a number of additional factors including the number of receptors affected, the duration of the works and the character of the noise. At this stage, without the actual contractor in place, the assessment is based on reasonable assumptions as to how the scheme would be constructed. Once the construction contractor has been appointed, and the methods of construction and programme of works have been finalised, the construction noise and vibration assessment would need to be updated. 4.5 For construction vibration, consideration has been given to the construction activities with the potential to give rise to the highest levels of vibration at receptors. These were considered to be vibratory earthwork compacting works and piling activities, which would be associated with the construction of structures and earthworks. Predictions of likely vibration levels from these activities have been made for some of the likely closest sensitive receptors, based on the formulae provided in BS 5228-2: 2009 + A1: 2014 - Code of practice for noise and vibration control on construction and open sites, Part 2: Vibration (BS 5228-2) (DD 14.2.4). Andrew Stephen Clarke / March 2018 7 of 31
4.6 For the operational assessment, noise levels have been calculated at all residential dwellings and other sensitive receptors within the calculation area as defined in Section 14.4.3 of the ES Supplement (DD 2.4.1). Noise levels at receptors have been calculated using the CadnaA noise modelling package, which incorporates the methodology contained in the Calculation of Road Traffic Noise, 1988 (CRTN) (DD 14.3.1) and supplemental guidance in HD 213/11 (DD 14.2.5). The following comparisons have been made in accordance with the guidance in HD 213/11: Short-term noise changes on scheme opening - by comparing the Do Minimum (DM) Opening Year (2022) predictions with the Do Something (DS) Opening Year (2022) predictions; Long-term noise changes, without the scheme in place by comparing DM 2022 predictions with DM Design Year (2037) predictions; and Long-term noise changes, with the scheme in place by comparing DM 2022 predictions with DS 2037 predictions. 4.7 In assessing the operational noise impact of the scheme, consideration has been given to the magnitude of impact categories for traffic noise detailed in HD 213/11 (DD 14.2.5) for both the shortterm and long-term. A change in road traffic noise of 1 db in the short-term, for example when a project is opened, is the smallest that is considered perceptible. In the long-term, a 3 db change is the smallest that is considered perceptible. These magnitude of change criteria have been developed following research into traffic noise and its impact on people. Many of the studies undertaken considered traffic noise and its effect on people in terms of nuisance and annoyance. The early studies focussed on sites where conditions were generally steady (ie. no sudden changes had Andrew Stephen Clarke / March 2018 8 of 31
taken place) and these studies yielded steady state relationships between noise exposure and nuisance. Later studies indicated that people were more sensitive to abrupt changes in traffic noise (such as on scheme opening) than would have been expected using the steady state relationships. The differences in the short term and long term magnitudes of impact criteria used, reflects the increased sensitivity of people to noise changes on a scheme s opening. 4.8 In terms of the significance of effects, as discussed in paragraph 3.36 of HD 213/11 (DD 14.2.5), in terms of road traffic noise, a standard methodology has not yet been developed to assign significance according to both value / sensitivity and magnitude. Instead, HD 213/11 advises that the magnitude of traffic noise impact from a road project should be classified into levels of impact, in order to assist with the interpretation of the road project. 4.9 Given the distance of the scheme to the nearest sensitive receptors and the smooth, new road surface to be introduced, operational ground-borne vibration was not considered to be a significant issue. Vibration nuisance predictions were undertaken and reported following the procedure outlined in HD 213/11 (DD 14.2.5). 4.10 Section 14.4 and Appendix 14B of the ES Supplement (DD 2.4.1) provide further details of the methodologies followed for the construction and operational assessments and the assessment criteria adopted. 4.11 Consideration was given to nearby sensitive receptors, including residential properties, schools, churches, cemeteries and healthcare facilities. In addition to the HD 213/11 assessment tables which summarise the overall operational impacts of the proposed scheme, predicted noise levels at a number of representative sample receptors have been presented in assessment to aid the reader in understanding the impacts of the scheme in particular areas. A separate section has been provided considering the impacts of the scheme on the residential properties located within NAPPA no 362, Andrew Stephen Clarke / March 2018 9 of 31
which has been identified by Welsh Government as one of those locations in Wales currently exposed to the highest noise levels from road traffic. 4.12 Colour noise change contour plots have also been provided to visually illustrate predicted short-term and long-term noise changes in the area as a result of the proposed scheme. Andrew Stephen Clarke / March 2018 10 of 31
5 Assessment Results Environmental Statement 5.1 The construction and operational noise and vibration assessment results are presented in Section 14.8 of the ES (DD 2.2.12). The results are not discussed further in this Proof, instead the assessment results provided within the ES Supplement (DD 2.4.1) are provided and discussed. Andrew Stephen Clarke / March 2018 11 of 31
6 Assessment Results ES Supplement 6.1 The construction and operational noise and vibration assessment results are presented in Section 14.8 of the ES Supplement (DD 2.4.1). Construction 6.2 Sixteen main works locations were identified as having potential to cause construction noise impacts, either due to their close proximity to receptor groups, or the likely equipment and processes required for the works. 6.3 As detailed in Section 14.8.1.2 of the ES Supplement (DD 2.4.1), the vast majority of construction works would take place during typical daytime hours. However, it is anticipated that some construction works would need to be undertaken during evening and weekend possessions. There is the potential for some nighttime working on occasion. Further details of these construction activities are provided in the Constructability and Phasing Report (DD 6.2.26). Construction Noise 6.4 The potential for significant effects at nearby receptors has been assessed based on criteria derived from the ABC method detailed in Annex E of BS 5228-1 (DD 14.2.3). The numbers of dwellings and other sensitive receptors (OSRs) where construction noise levels are expected to be close to or exceed the relevant threshold value from BS 5228-1 are presented in Table 14.10 of the ES Supplement (DD 2.4.1). Andrew Stephen Clarke / March 2018 12 of 31
6.5 The assessment concludes that major impacts associated with construction noise could be expected at numerous locations during typical working hours, where dwellings are in close proximity to the proposed works. This is likely to include locations such as Gurnos, Jones St Bridge and Pentwyn Cynon. However, it should be recognised that any such impacts would be temporary in nature. Given the transient nature of construction activities, the worst case predicted construction noise levels provided are likely to occur for a limited period, when construction activities are located in close proximity to the receptors. At other times it is expected that construction noise levels would be lower, and the impacts may be less than those presented in Table 14.10 of the ES Supplement (DD 2.4.1). 6.6 During evening, weekend and night-time periods, BS 5228-1 (DD 14.2.3) Threshold Noise Limits would be lower than those presented in Table 14.9 of the ES Supplement (DD 2.4.1), to represent the more noise sensitive nature of these periods. There is the potential for evening and/or weekend working to be required in the vicinity of structures, some of which are near to sensitive receptors. There is therefore the potential for greater numbers of major adverse noise impacts at these locations during evening and weekend working, depending on the proximity and duration of the works proposed. 6.7 Given the potential for greater numbers of major adverse impacts during evening, night-time or over weekend periods, the need for such working would be minimised by the construction contractor. More stringent noise limits would be set for any works outside of typical construction working hours. These requirements, along with proposed noise and vibration mitigation measures, are included in the Register of Environmental Actions and Commitments (REAC) (DD 6.2.21). Andrew Stephen Clarke / March 2018 13 of 31
6.8 Details of noise and vibration mitigation measures that could be adopted during construction are provided in Section 14.9.1 of the ES Supplement (DD 2.4.1) and are discussed further in Section 8 of this Proof below. Construction Vibration 6.9 Of the construction activities proposed, those associated with piling and vibratory earthwork compacting works are likely to give rise to the highest vibration levels at nearby receptors. 6.10 For piling works, predicted vibration levels illustrate that driven piling would not be an appropriate piling technique at the proposed works near Trewaun. Instead, it is proposed to use a low vibration technique, for example rotary bored piling. With one of these techniques adopted, vibration levels would likely to be around 1 mm/s or lower at a distance of 15 m, based on the data provided in Table D.6 of Annex D of BS 5228-2 (DD 14.2.4). At these levels, there would be minimal adverse effects associated with piling vibration at Trewaun. Low vibration piling techniques are also likely to be needed at other locations where sensitive receptors are in close proximity. 6.11 For vibratory compaction works, separation distances of 30 and 50 m were considered within the ES Supplement (DD 2.4.1), which would be typical distances for these works. Predicted vibration levels are provided in Table 14.13 of the ES Supplement (DD 2.4.1). The vibration levels predicted are likely to be perceptible to residents in residential dwellings and are likely to lead to complaint according to the guidance in BS 5228-2 (DD 14.2.4). Careful consideration would need to be given to earth compaction in close proximity to sensitive receptors. The Construction Environmental Management Plan (CEMP) would include a requirement for Andrew Stephen Clarke / March 2018 14 of 31
vibration soil compaction plant to be set to a low amplitude setting when operating in close proximity to sensitive receptors, where possible. 6.12 The predicted vibration levels fall well below the vibration levels defined in BS 7385-2 (DD 14.2.1) which could give rise to cosmetic damage to buildings. In addition, given the transient nature of the soil compaction works, this level of vibration would only be experienced for short duration, for example two to three days, when the compaction works occur at the nearest position to the properties. 6.13 Consideration is given to potential noise and vibration mitigation measures during construction in Section 14.9.1 of the ES Supplement (DD 2.4.1) and is discussed further in Section 7 of this Proof below. Operational Noise 6.14 Section 14.8.3 of the ES Supplement (DD 2.4.1) provides the operational assessment results for the proposed scheme. includes consideration of predicted noise levels at sample receptors (residential dwellings plus health, education and community facilities) along the scheme corridor, the HD 213/11 assessment tables and noise level changes at dwellings within the NAPPA. Short-term Impacts at Sample Receptors 6.15 A total of 38 sample receptors have been selected along the scheme corridor to enable an understanding of the typical magnitudes of noise change, and the reasons for these changes, for different communities. The locations of the sample receptors selected are provided in Figure 14.7 of the ES Supplement (DD 2.4.1). These properties are not intended to be representative of the absolute worst case noise effects for receptor groups along the proposed scheme corridor. It Andrew Stephen Clarke / March 2018 15 of 31
6.16 Noise changes on scheme opening are variable along the length of the scheme and are dependent upon a number of factors including the change in alignment, introduction of new roads/slip roads, changes in traffic flows, traffic speeds and the proportion of heavy vehicles, the proposed vertical alignment (compared to the current situation), the inclusion of a low noise road surface (compared to the current situation) and the presence of proposed environmental barriers. The short term noise change contour plot provided in Figure 14.4 of the ES Supplement (DD 2.4.1) visually illustrates the likely noise changes expected along the route. 6.17 Of the sample receptors selected, 22 are residential dwellings. Predicted noise levels on scheme opening for the sample residential dwellings are provided in Table 14.14 of the ES Supplement (DD 2.4.1). 6.18 Perceptible adverse noise impacts on scheme opening are anticipated at eight of the sample dwellings considered. Seven of these are predicted to fall within the minor adverse magnitude of impact category, whilst one would fall within the moderate adverse magnitude of impact category. The underlying reasons for the perceptible increases in noise level are discussed in Section 14.8.3.1 of the ES Supplement (DD 2.4.1). It should be noted that at some dwellings a noise increase is anticipated on one façade, whilst a noise decrease is predicted on a different façade. 6.19 Perceptible noise benefits on scheme opening are anticipated for three of the sample dwellings considered, falling within the minor and major beneficial impact categories. The underlying reasons for the perceptible decreases in noise are discussed in Section 14.8.3.1 of the ES Supplement (DD 2.4.1). Andrew Stephen Clarke / March 2018 16 of 31
6.20 The remaining 11 sample dwellings are expected to experience negligible noise changes with the proposed scheme in place, on scheme opening. 6.21 16 of the sample receptors selected are health, educational and community facilities. Predicted noise levels on scheme opening for the sample health, educational and community facilities are provided in Table 14.16 of the ES Supplement (DD 2.4.1). 6.22 Of the sample facilities considered, four (Dowlais Primary School (Junior Department), Morlais Medical Centre, Pant Primary School and Ysgol Gyfun Rhydywaun) would be expected to experience a minor adverse noise increase on scheme opening. This would principally be due to a predicted increase in traffic using the local road network in these areas. In the case of Pant Primary School this would also be as a consequence of traffic using the Prince Charles Hospital junction, rather than noise from traffic on the A465 itself. 6.23 Conversely, two of the sample facilities (Hirwaun County Primary School and Hirwaun Infants and Nursey School) would be expected to experience minor decreases in noise level on scheme opening, principally as a result of the realignment of the A465 to the south, as well as the application of LNRS. 6.24 The remaining 10 sample health, educational and community facilities are expected to experience negligible noise changes with the proposed scheme in place, on opening. Long-term Impacts at Sample Receptors Andrew Stephen Clarke / March 2018 17 of 31
6.25 Generally, the sample receptors see a similar impact to that experienced in the short term, although the magnitude of change is generally lower in the long term compared to the short term. 6.26 Noise changes in the long term situation, with the scheme in place, are again variable along the length of the scheme. They are dependent upon a number of factors including the change in alignment, introduction of new roads/slip roads, the inclusion of the Cynon Valley Gateway (Aberdare Bypass) scheme, changes in traffic flows, traffic speeds and the proportion of heavy vehicles, the proposed vertical alignment (compared to the current situation), the inclusion of a low noise road surface (compared to the current situation) and the presence of proposed environmental barriers. The long term noise change contour plots provided in Figures 14.5 (with the proposed scheme) and 14.6 (without the proposed scheme) of the ES Supplement (DD 2.4.1) visually illustrate the likely noise changes expected along the route. 6.27 Predicted noise levels in the long term, with the scheme in place, for the sample residential dwellings are provided in Table 14.15 of the ES Supplement (DD 2.4.1). 6.28 Perceptible adverse noise impacts in the long term, with the scheme in place, are anticipated at four of the sample dwellings considered, all falling within the minor adverse magnitude of impact category. The underlying reasons for the perceptible increases in noise level are discussed in Section 14.8.3.1 of the ES Supplement (DD 2.4.1). 6.29 A perceptible noise benefit in the long term, with the scheme in place, is anticipated at a single sample dwelling, falling within the moderate beneficial impact category. The underlying reasons for the perceptible decreases in noise are discussed in Section 14.8.3.1 of the ES Supplement (DD 2.4.1). Andrew Stephen Clarke / March 2018 18 of 31
6.30 The remaining 17 sample dwellings are expected to experience negligible noise changes with the proposed scheme in place, in the long term. 6.31 Predicted noise levels in the long term, with the scheme in place, for the sample health, educational and community facilities are provided in Table 14.17 of the ES Supplement (DD 2.4.1). 6.32 Of the sample facilities considered, only Penywaun Primary School is predicted to experience a perceptible noise increase in the long term, within the minor adverse magnitude of impact category. This is due to the influence of the proposed Cynon Valley Gateway (Aberdare Bypass) scheme that is included in the Do Something scenario in 2037. This Cynon Valley Gateway (Aberdare Bypass) project has been modelled without any mitigation, as the project is not currently at the design stage. This scheme, were it to proceed, would be subject to its own ES to assess the impacts and consider mitigation measures. A noise increase of this magnitude would be unlikely to occur in practice even if both the proposed scheme and the proposed Cynon Valley Gateway (Aberdare Bypass) scheme were to be in operation by 2037. Any increase associated with the proposed A465 scheme itself at Penywaun Primary School would be negligible. 6.33 The remaining 15 sample health, educational and community facilities are expected to experience negligible noise changes with the proposed scheme in place, in the long term. HD 213/11 Summary Tables Andrew Stephen Clarke / March 2018 19 of 31
6.34 The approach followed within the HD 213/11 (DD 14.2.5) methodology for reporting noise impacts is conservative, with the least beneficial impact at each receptor location being considered. For example, if a dwelling was predicted to experience a 7 db reduction in noise level for one property façade as a result of the proposed scheme, but a 1 db increase in noise level for another façade, it would only be the 1 db noise increase that was reported in the HD 213/11 assessment tables. The larger noise benefit at that dwelling would not be reported in the HD 213/11 assessment tables. This approach to reporting impacts should be noted when considering the assessment findings detailed in the sections that follow. 6.35 There is one exception to this approach, in the consideration of noise impacts for those dwellings within the NAPPA. These dwellings have been designated on the basis of the noise levels experienced for the facades facing towards the existing A465. As such, the noise impacts reported for the dwellings within the NAPPA (in the section that follows) are for the relevant façade that has led to its designation. 6.36 Table 14.19 of the ES Supplement (DD 2.4.1) shows that on scheme opening, with the scheme and proposed mitigation measures in place: The majority of sensitive receptors (7,363) would experience no perceptible change in noise levels; 3,607 sensitive receptors would experience perceptible adverse noise impacts; and 395 sensitive receptors would experience perceptible beneficial noise impacts. 6.37 Overall, when comparing the amount of receptors that would experience a perceptible decrease in noise level against those that Andrew Stephen Clarke / March 2018 20 of 31
would experience a perceptible increase in noise level, the overall impact of the proposed scheme would be considered to be adverse in the short term. 6.38 Table 14.20 of the ES Supplement (DD 2.4.1) shows that in the long term, without the scheme in place: changes. No sensitive receptors would experience perceptible noise 6.39 Table 14.21 of the ES Supplement (DD 2.4.1) shows that in the long term, with the scheme and proposed mitigation measures in place: The vast majority of sensitive receptors (10,518) would experience no perceptible change in noise levels; 807 sensitive receptors would experience perceptible adverse noise impacts; and 40 sensitive receptors would experience perceptible beneficial noise impacts. 6.40 Overall, when comparing the amount of receptors that would experience a perceptible decrease in noise level against those that would experience a perceptible increase in noise level, the overall impact of the proposed scheme would be considered to be adverse in the long term. 6.41 It should be noted that the Cynon Valley Gateway (Aberdare Bypass) scheme is only included in the DS 2037 scenario, it is not included in the DM 2037 scenario. Therefore, the noise impacts associated with this unmitigated scheme are included in the long term with scheme analysis. Andrew Stephen Clarke / March 2018 21 of 31
6.42 A visual illustration of the noise change predicted in the short term and long term, with the proposed scheme and mitigation in place, is provided in Figures 14.4 and 14.5 of the ES Supplement (DD 2.4.1), which provide the daytime noise change contours in terms of the magnitude of impacts. 6.43 For comparison, a visual illustration of the noise change predicted in the long term, without the scheme in place, is provided in Figure 14.6 of the ES Supplement (DD 2.4.1). Noise levels within the NAPPA 6.44 According to information held in the existing Pavement Management System, the A465 at this location currently benefits from a low noise road surface (LNRS). The proposed scheme design introduces a new LNRS, and a new 2 m high environmental barrier to the south, designed to reduce noise at properties in the NAPPA. The height of the environmental barrier in the noise model has been selected to take into account the preservation of views from the properties in the NAPPA to the north, and to avoid excessive overshadowing in gardens adjacent to the environmental barrier. 6.45 Tables 14.24 and 14.25 of the ES Supplement (DD 2.4.1) present the short term and long term noise changes at all properties within the NAPPA. 6.46 Table 14.24 of the ES Supplement (DD 2.4.1) demonstrates that, when considering the property facades that face towards the A465, perceptible noise benefits are predicted on proposed scheme opening for 13 of the 20 residential properties situated within the NAPPA, due predominantly to the inclusion of the new LNRS and environmental barrier in this area. Noise changes for the remaining Andrew Stephen Clarke / March 2018 22 of 31
seven residential properties situated within the NAPPA are predicted to be imperceptible, falling within the negligible magnitudes of change categories. 6.47 For the long term assessment presented in Table 14.25 of the ES Supplement (DD 2.4.1), the short term magnitude of impact criteria have mistakenly been applied. The table is reproduced below, with the correct long term magnitude of impact criteria applied. Table 6.1 : Summary of long term noise changes at properties within NAPPA Receptor Do Minimum 2022, L A10,18h (db) Do Something 2037, L A10,18h (db) Noise level change (db) Magnitude of change 1 Beacons View Beacons View CF48 3NJ 2 Beacons View Beacons View CF48 3NJ 3 Beacons View Beacons View CF48 3NJ 4 Beacons View Beacons View CF48 3NJ 5 Beacons View Beacons View CF48 3NJ 6 Beacons View Beacons View CF48 3NJ 7 Beacons View Beacons View CF48 3NJ 8 Beacons View Beacons View CF48 3NJ 9 Beacons View Beacons View CF48 3NJ 31 Guest Cottages Guest Cottages CF48 3NT 32 Guest Cottages Guest Cottages CF48 3NT 33 Guest Cottages Guest Cottages CF48 3NT 34 Guest Cottages Guest Cottages CF48 3NT 1 Cross Houlson Street CF48 3NN 72.7 74.2 1.5 Negligible Adverse 64.4 62.9-1.5 Negligible Beneficial 59.5 59.2-0.3 Negligible Beneficial 57.9 59.8 1.9 Negligible Adverse 69.3 66.2-3.1 Minor Beneficial 69.4 66.7-2.7 Negligible Beneficial 70.9 69.7-1.2 Negligible Beneficial 71.1 70.1-1.0 Negligible Beneficial 71.3 70.5-0.8 Negligible Beneficial 71.6 65.1-6.5 Moderate Beneficial 70.6 64.0-6.6 Moderate Beneficial 69.8 62.4-7.4 Moderate Beneficial 68.6 61.5-7.1 Moderate Beneficial 64.4 64.5 0.1 Negligible Adverse Andrew Stephen Clarke / March 2018 23 of 31
Receptor Do Minimum 2022, L A10,18h (db) Do Something 2037, L A10,18h (db) Noise level change (db) Magnitude of change 2 Cross Houlson Street CF48 3NN 3 Cross Houlson Street CF48 3NN 4 Cross Houlson Street CF48 3NN 5 Cross Houlson Street CF48 3NN 6 Cross Houlson Street CF48 3NN 63.9 64.2 0.3 Negligible Adverse 63.5 63.9 0.4 Negligible Adverse 63.1 63.8 0.7 Negligible Adverse 63.1 63.8 0.7 Negligible Adverse 63.5 63.9 0.4 Negligible Adverse 9 Houlson Street CF48 3NW 67.4 67.6 0.2 Negligible Adverse 6.48 In the long term, the replacement Table 14.25 above demonstrates that, when considering the property facades that face towards the A465, perceptible noise benefits are predicted for five of the residential properties situated within the NAPPA. No perceptible noise increases are predicted for any of the residential properties within the NAPPA in the long term. Noise changes for the remaining 15 residential properties situated within the NAPPA are predicted to fall within the negligible magnitudes of change categories. 6.49 Overall, the proposed scheme and associated noise mitigation is considered to have a beneficial noise impact for properties situated within the NAPPA. Andrew Stephen Clarke / March 2018 24 of 31
7 Mitigation Strategy 7.1 Noise and vibration mitigation measures are detailed in Section 14.9 of the ES Supplement (DD 2.4.1) and discussed below. Construction Noise and Vibration 7.2 The construction design incorporates measures that represent best practice with respect to noise and vibration control, examples of which include: In order to undertake rock breaking in the Cefn Coed cutting, it is proposed to used drill and burst techniques which would reduce the noise levels compared to traditional hydraulic methods of rock breaking; It is proposed to use either rotary boring or augering to construct the retaining walls adjacent to the Trewaun junction, which would significantly reduce noise levels compared to standard driven piling techniques; and The vast majority of works are not proposed during the sensitive evening and / or night-time periods or during Sundays or Bank Holidays. 7.3 These requirements, along with proposed noise and vibration mitigation measures, are included in the Register of Environmental Actions and Commitments (REAC) (DD 6.2.21). 7.4 Despite the application of these measures, it is acknowledged that there remains the potential for significant construction noise and vibration impacts at some locations. Further mitigation measures, to reduce potential impacts are detailed below. Andrew Stephen Clarke / March 2018 25 of 31
7.5 A Construction Environmental Management Plan (CEMP) would be developed setting out the following information in relation to the control of noise and vibration: good practice noise and vibration control measures that the contractor would adopt; noise monitoring procedures, including equipment specification, locations, duration and reporting requirements; vibration monitoring procedures designed to demonstrate that the relevant thresholds within BS 7385-2 and BS 5228-2 are not exceeded; duties and responsibilities for a Public Liaison Officer who would be responsible for the day-to-day communication on noise and vibration issues with the EHO and the general public; contact details (24 hours, seven days a week) for on-site personnel responsible for noise and vibration management; and complaint response protocols. 7.6 Compliance with this CEMP would be a requirement of the contract between the Welsh Government and the key contractors appointed to undertake the works. 7.7 In the CEMP, the selected Contractor would be required to apply Best Practicable Means (BPM) to minimise any residual noise and vibration impact during construction. A list of the measures to be adopted as a minimum are provided in Section 14.9.1.2 of the ES Supplement (DD 2.4.1), to ensure that noise and vibration levels were to be attenuated as far as reasonably practicable. Andrew Stephen Clarke / March 2018 26 of 31
7.8 It is anticipated that one or a number of applications for prior consent would be made for the construction works (under the Control of Pollution Act 1974 (DD 3.1.13)), as and when plant lists, programmes and working methods become sufficiently finalised. Each application would contain particulars of the works, working methods and noise control measures and would be submitted to the relevant local authority for approval. The aim of any Section 61 application would be to demonstrate compliance with the relevant noise and vibration thresholds, or to establish that the BPM have been employed to control noise emissions. The local authority may attach conditions to each consent, including a limit on duration of the works. 7.9 During the construction, the contractor would be required, through the procedures set out in the CEMP and Section 61 Applications, to control the effects of noise and vibration from the construction works. However, there may be circumstances where noise impacts would arise which would need to be mitigated still further. In certain circumstances, the Welsh Government would either provide and install (free of charge), or provide grant aid for, noise insulation and / or arrange temporary re-housing (or help residents to arrange it for themselves and recoup the costs). Operational Noise 7.10 As detailed in Section 14.9.2 of the ES Supplement (DD 2.4.1), the proposed scheme design incorporates various features that would be effective in reducing potential noise increases, which can be summarised as follows: Provision of a new low noise road surface (LNRS) for much of the scheme. A section of the scheme between just north-east of Croesbychan junction and just west of Baverstock junction has few sensitive receptors in close proximity and a hot rolled Andrew Stephen Clarke / March 2018 27 of 31
asphalt (HRA) surface has been assumed for this section of the scheme, instead of a LNRS; the introduction of various cuttings that would screen road traffic noise from certain receptor locations (such as west of Gurnos and at Trewaun); and, the inclusion of various environmental barriers in the design that would provide screening of road traffic noise at local receptors. 7.11 A schedule of the environmental barriers included in the proposed scheme design is presented in Table 14.27 of the ES Supplement (DD 2.4.1). The locations of these environmental barriers are illustrated on the short-term and long term noise change contour plots provided in Figures 14.4 and 14.5 of the ES Supplement (DD 2.4.1). 7.12 The above noise mitigation measures are all considered as inherent aspects of the proposed scheme design, and therefore their effects are reflected in the assessment presented in this Proof. Andrew Stephen Clarke / March 2018 28 of 31
8 Conclusions 8.1 The assessment has been undertaken in accordance with DMRB Volume 11 Section 3 Part 7 Noise and Vibration, HD 213/11 Revision 1 (HD 213/11) (Highways Agency, 2011b) (DD 14.2.5). The predicted noise levels for all noise sensitive receptors are presented in Appendix 14F (ES Supplement Volume 2) (DD 2.4.1). 8.2 Despite the application of best practice mitigation measures, major construction noise impacts could occur at properties in close proximity to the proposed works. However, it should be recognised that any such impacts would be temporary in nature. 8.3 Vibration during some piling and ground compaction works is likely to be perceptible to residents in nearby residential dwellings for limited durations. However, expected vibration levels fall below those which could give rise to cosmetic building damage. 8.4 The proposed scheme design includes the use of low noise road surfacing (LNRS), and the use of environmental barriers that provide noise screening for noise sensitive residential dwellings. 8.5 It should be noted that the assessment includes the unmitigated effect of the proposed Cynon Valley Gateway (Aberdare Bypass) scheme in the long term, as the long term traffic forecasts assume it would be operational by 2037 if the proposed scheme were to be constructed. 8.6 In the short term, with the proposed mitigated scheme, there are predicted to be 3,577 dwellings and 30 other noise sensitive receptors (total 3,607) that would experience a perceptible noise increase in noise level of at least 1 db. Conversely there are predicted to be 391 dwellings and four other noise sensitive Andrew Stephen Clarke / March 2018 29 of 31
receptors (total 395) that would experience a decrease in noise level of at least 1 db. 8.7 In the long term, with the proposed mitigated scheme, there are predicted to be 798 dwellings and nine other noise sensitive receptors (total 807) that would experience an increase in noise level of at least 3 db during the daytime. By comparison there are predicted to be 40 dwellings that would experience a decrease in noise level of at least 3 db. For the long term night-time situation, four dwellings are predicted to experience perceptible noise increases, whilst two dwellings are predicted to experience perceptible noise decreases. 8.8 Overall, when considering the numbers of receptor experiencing perceptible increases and decreases in the area, the proposed scheme is considered to have an adverse noise impact, both on scheme opening and in the long term. 8.9 A single Noise Action Plan Priority Area (NAPPA) number 362 is located within the study area, to the south of the proposed scheme route in Dowlais. When considering the facades that face the A465, perceptible noise decreases are predicted for 13 properties within the NAPPA in the short term, with no perceptible noise increases anticipated. In the long term situation, five properties within the NAPPA are predicted to experience perceptible noise benefits, with no perceptible noise increases again anticipated. 8.10 Overall, the proposed scheme is considered to have a beneficial noise impact on properties within the NAPPA. Andrew Stephen Clarke / March 2018 30 of 31
9 Declaration 9.1 My Proof of Evidence includes all facts which I regard as being relevant to the opinions which I have expressed and the Inquiry s attention has been drawn to any matter which would affect the validity of that opinion. 9.2 I believe the facts I have stated in this Proof of Evidence are true and that the opinions expressed are correct. 9.3 I understand my duty to the Inquiry to assist it with matters within my expertise and I believe that I have complied with that duty. Andrew Stephen Clarke / March 2018 31 of 31