SECTION 9 9-1 Noise and Vibration 9.1 Introduction This chapter of the ES contains the assessment of construction noise and vibration expected from the works required to be undertaken on A44 New Road. Calculations of noise and vibration levels during the proposed construction activities have been undertaken at the locations of the closest, worst case, residential receptor locations. 9.2 Study Area The study area considers the red line boundary, locations where the construction activities will take place and the locations of the closest sensitive receptors which are located either side along Bridge Street on the east side of River Severn, the Premier Inn Hotel located on New Road and commercial buildings located in the area of Cripplegate Park. These are shown in Plate 9.1 below. Plate 9.1 Closest Sensitive Receptors to Construction Works.
Transcript
SECTION 9
9-1
Noise and Vibration
9.1 Introduction This chapter of the ES contains the assessment of construction noise and vibration expected from the works required to be undertaken on A44 New Road. Calculations of noise and vibration levels during the proposed construction activities have been undertaken at the locations of the closest, worst case, residential receptor locations.
9.2 Study Area The study area considers the red line boundary, locations where the construction activities will take place and the locations of the closest sensitive receptors which are located either side along Bridge Street on the east side of River Severn, the Premier Inn Hotel located on New Road and commercial buildings located in the area of Cripplegate Park. These are shown in Plate 9.1 below.
Plate 9.1 Closest Sensitive Receptors to Construction Works.
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In addition, dwellings located to the south west of the works on Bromwich Road have been also considered in the assessment.
9.3 Methodology
9.3.1 Proposed Construction Activities The scheme will involve undertaking a number of construction activities, for which the noise impacts will be assessed. The activities are described in Chapter 3: Development Proposals and are outlined below:
• Installation of a round culvert inlet structure in Cripplegate Park;
• Installation of box culvert trenched under New Road from the culvert inlet to the playing fields (Kings School);
• Installation of a pipe under New Road;
• Raising of the road and the footway from the outside area of the Cricket Club to just past the main entrance;
• Changes to the three splitter islands at junctions with Hylton Road, North Parade & All Saints Road;
• Tree removal on New Road; and
• Hedgerow removal at Cripplegate Park gate.
9.3.2 Calculation Methodology Calculation of noise propagation outdoors is undertaken in line with the methodology set out in ISO 9613-2:1996: Acoustics – Attenuation of sound during propagation outdoors – Part 2: General method of calculation (ISO, 1996) contained in BS5228:2009+A1:2014 Code of practice for noise and vibration control on construction and open sites. The sound power levels from onsite activities during these phases were based on data available in BS5228-1:2009+A1:2014 (British Standard Institute (BSI), 2014n).
Part 1: Noise of the British Standard 5228 (BS 5228-1) provides suitable methods for the calculation of noise from construction activities, including basic information regarding noise levels from a range of construction equipment. For the calculation of construction noise at the receptor locations the selected A-weighted sound power levels (indicating the total acoustic energy that a piece of equipment radiates to its environment) of the plant and equipment are corrected so to consider; the ‘Percentage On-time’ (portion of time in which the equipment is operating at its maximum power), ‘Duration of Activity’ (amount of time in relation to the ‘Shift Duration’ in which the equipment is expected to operate), distance between sound sources and receptors, percentage of soft ground and any screening corrections from obstacles between the propagation path of the sound.
Prediction of vibration levels is undertaken following the methods contained in Annex E of BS5228-2:2009+A1:2014 Code of practice for noise and vibration control on construction and open sites – Part 2: Vibration (BSI, 2014v).
The list of plant and equipment and associated acoustic data considered during the construction phase is presented in Appendix 9.1.
The proposed standard working hours that have been considered for the calculations are 07:30 to 16:30 Monday to Friday only. The proposed construction hours cover nine hours of the daytime reference period. No work activity is proposed during the night-time reference period and at any time during Weekends or Bank Holidays.
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9.4 Regulatory Policy Framework
9.4.1 Policy and Legislation The section briefly describes the main legislation and policy that will be relevant to undertaking the construction noise and vibration assessment.
Control of Pollution Act 1974 (CoPA)
The Control of Pollution Act (CoPA) grants powers to deal with noise nuisances and places a duty on local authorities to inspect their areas from time to time in order to detect anything which should be dealt with under the Act. It also defines and empowers local authorities to create noise abatement zones within their areas. However, few local authorities have chosen to do this.
Much of CoPA has now been replaced and extended by the Environmental Protection Act 1990. However, Sections 60 and 61 which relate to noise and vibration from construction sites remain relevant.
Section 60 of CoPA allows a local authority to serve a notice of its requirements for the control of site noise to the individual or entity carrying out or controlling the works. The notice may stipulate noise limits for work, particular plant or machinery that should be avoided, hours during which construction activities may be carried out and provide for any change in circumstances.
Section 61 (S61) of CoPA concerns the procedures adopted when a contractor or developer approaches the local authority prior to any construction activities taking place, with the intention of agreeing noise and vibration limits in advance of works.
If consent is granted under S61, then this would be considered a valid defence by the Magistrate’s court if the local authority was to later reverse its position and pursue an action under Section 60.
Environmental Protection Act (EPA) 1990
Part III, Section 79, of the Environmental Protection Act 1990 (EPA 1990) defines what activities may constitute a Statutory Nuisance, and what activities are specifically exempt. The Section imposes a duty on local authorities to periodically survey environmental noise levels and to investigate noise complaints. The Act requires local authorities to serve notice when noise nuisance exists. Under these statutory nuisance provisions, the operators of a site or facility could be required to adopt Best Practicable Means to abate noise nuisance at any time once operations have commenced. It is, therefore, essential that potential nuisance effects are properly considered, so as to ensure that the operators are seen to adopt best practice, and that any potential requirements for mitigation are considered.
Noise Policy Statement for England, NPSE
Any new development or works must take into consideration the Government’s policy on noise. This is set out in the Noise Policy Statement for England (NPSE) which was published in March 2010 (Department for Environment Food and Rural Affairs, 2010). It contains the high level vision of promoting good health and good quality of life (well-being) through the effective management of noise. It is supported by three aims which are to be achieved through the effective management and control of environmental, neighbour and neighbourhood noise within the context of Government policy on sustainable development. These aims are:
• avoid significant adverse impacts on health and quality of life;
• mitigate and minimise adverse impacts on health and quality of life, and;
• where possible, contribute to the improvement of health and quality of life.
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The aims would need to be considered when undertaking the impact assessment, especially the treatment of any adverse impacts, but also the possibility for enhancement. In addition to the aims of Government Policy, the NPSE also introduces effect levels for noise. These effect levels are:
• NOEL – No Observed Effect Level. This is the level below which no effect can be detected. In simple terms, below this level, there is no detectable effect on health and quality of life due to the noise.
• LOAEL – Lowest Observed Adverse Effect Level. This is the level above which adverse effects on health and quality of life can be detected.
• SOAEL – Significant Observed Adverse Effect Level. This is the level above which significant adverse effects on health and quality of life occur.
No values are assigned to these in the NPSE as it is considered that they are best determined on a scheme by scheme basis.
9.4.2 Guidance This section provides the relevant noise guidance and criteria that has been considered for undertaking the noise impact assessment associated with the construction activities at A44 New Road in Worcester. A summary of each document is set out below.
Design Manual for Roads and Bridges (DMRB)
The magnitude and significance of the impact defined in HA 205/08 (DMRB Volume 11 Section 2 Part 5) is considered in this assessment. The Design Manual for Roads and Bridges document HD213/11 – Noise and Vibration (Highways Agency et al., 2011) sets out the methodology to be followed when undertaking an assessment for road schemes.
Magnitude of impact
The noise bands (i.e. change in noise) defined for short term increases have been considered applicable to construction noise. These are presented in Table 9.1.
Table 9.1 Magnitude of Impact and Typical Descriptors, DMRB.
Magnitude of Impact
No change
Negligible
Minor
Moderate
Major
Typical Criteria Descriptors Short-term increase (noise band in dB)
Major Loss of resource and/or quality and integrity of resource; severe damage to key characteristics, features or elements
+5.0
Moderate Loss of resource, but not adversely affecting the integrity; partial loss of/damage to key characteristics, features or elements
3.0 – 4.9
Minor Some measurable change in attributes, quality or vulnerability; minor loss of, or alteration to, one (maybe more) key characteristics, features or elements
1.0 – 2.9
Negligible Very minor loss or detrimental alteration to one or more characteristics, features or elements
0.1 – 0.9
No Change No loss or alteration of characteristics, features or elements; no observable impact in either direction
0.0
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Significance of effect
The significance of effect is determined from the combination of the value of the resource and the magnitude of impact as shown in Table 9.2.
Table 9.2 Significance of effect, DMRB.
Magnitude of Change
Value / Sensitivity of Receptor (Defined in Table 9.6)
Very High High Medium Low Negligible
Major Vary Large Large Large Moderate Slight
Moderate Large Moderate Moderate Slight Neutral
Minor Moderate Slight Slight Neutral Neutral
Negligible Slight Slight Neutral Neutral Neutral
No Change Neutral Neutral Neutral Neutral Neutral
British Standard BS5228:2009+A1:2014 Code of practice for noise and vibration control on construction and open sites – Part 1: Noise
This code of practice provides guidance and recommendations on methods for the measurement of construction noise and assessing its impact on those exposed to it. It also makes reference to the legislative background to noise control on construction sites, and gives recommendations for basic methods of noise control. Also, suitable methods are provided for the calculation of noise from construction activities, including basic information regarding noise levels from a range of construction equipment.
As stated in the DMRB (HD213/11), the significance of noise impacts caused by construction activities should be evaluated according to the methods described in Annex E of the BS 5228-1 (BSI, 2014n), unless other methods have already been agreed with the Overseeing Authority, where the noise trigger levels and criteria for different time periods is provided in Table E.2 of the British Standard.
Annex E of BS 5228-1 describes methods for evaluating the potential significant effect of construction noise depending on the existing noise level at the site. The Annex presents the ABC method which considers that a potential adverse effect is indicated when the site noise level exceeds the value listed in an A/B/C category which is dictated by the existing noise level. As the daytime existing levels at the site, from the Extrium tool (Extrium, 2015), are of 75dB category C is considered as the threshold for SOAEL. The LOAEL has been set in line with Category A from BS 5228-1.
Table 9.3 is adapted from Table E.1 in BS 5228-1 Annex E where the impact thresholds for construction activities at residential premises have been classified in terms of government policy based on the ABC Method set out in BS 5228-1 In relation to construction noise, day is 07:00 to 19:00, evening is 19:00 to 23:00 and night is 23:00 to 07:00. The level provided for the day time is for the entire period, whereas that for evening and night is applicable to any single hour within the respective period.
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Table 9.3 Noise Effect Levels from Construction Works at Dwellings
Construction noise effect level (BS5228-
Threshold Value, 1m in front of the relevant façade (dB)
Lowest Observed Adverse Effect
Level (LOAEL) – Category A in
BS5228-1
Day 65 dB LAeq, daytime
Evening 55 dB LAeq,1h
Night 45 dBLAeq,1h
Significant Observed Adverse
Effect Level (SOAEL) – Category
C in BS5228-1
Day 75 dB LAeq, daytime
Evening 65 dB LAeq,1h
Night 55 dBLAeq,1h
Unacceptable Observed Adverse
Effect Level (UOAEL)
Day 85 dB LAeq, daytime
Evening 75 dB LAeq,1h
Night 65 dBLAeq,1h
The effects of construction noise are temporary and defined by the intrusion that construction noise causes in the existing noise environment (or soundscape) of the area. Noise levels above the SOAEL in Table 9.3 are significant adverse and BS 5228-1 states that noise insulation may be offered (using the discretionary powers provided by Regulation 5 of the Noise Insulation Regulations) if those noise levels remain for a long enough period of time (i.e. for a period of 10 or more days of working in any 15 consecutive days or for a total number of days exceeding 40 in any 6 consecutive months (BSI, 2014n)).
British Standard BS5228:2009+A1:2014 Code of practice for noise and vibration control on construction and open sites – Part 2: Vibration
BS 5228 2009, Part 2: Vibration (BSI, 2014v) provides guidance in relation to the effects of construction vibration upon the surroundings. Vibration nuisance is frequently associated with the assumption that, if vibration can be felt, then damage is inevitable. However, considerably greater levels of vibration are required to cause damage to buildings and structures. In any neighbourhood, some individuals will be more sensitive to vibration than others.
Vibration on Humans
This British Standard provides guidance on human response to vibration in buildings where the SOAEL for the vibration level in terms of Peak Particle Velocity (PPV) is defined as above 1.0 mm/s. This is reproduced in Table 9.4.
Table 9.4 Magnitude of impact from vibration levels (Human Response).
Vibration Level, PPV
Effect Magnitude of impact
Effect level
0.14 mm/s
Vibration might be just perceptible in the most sensitive situations for most vibration frequencies associated with construction. At lower frequencies, people are less sensitive to vibration.
Negligible / No Change
NOAEL
0.3 mm/s Vibration might just be perceptible in residential environments.
Minor LOAEL
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Table 9.4 Magnitude of impact from vibration levels (Human Response).
Vibration Level, PPV
Effect Magnitude of impact
Effect level
1.0 mm/s
It is likely that vibration of this level in residential environments will cause complaint, but can be tolerated if prior warning and explanation has been given to residents.
Moderate SOAEL
10 mm/s Vibration is likely to be intolerable for any more than a very brief exposure of this level.
Major UOAEL
Vibration on Buildings
BS 7385-2:1993 ‘Evaluation and measurement for vibration in buildings – Part 2: Guide to damage levels from ground borne vibration’ (BSI, 1993) provides guidance on vibration levels likely to result in cosmetic damage, and is referenced in BS 5228-2:2009 + A1:2014 (BSI, 2014v). Guide values for transient vibration, above which cosmetic damage could occur, are given in Table 9.5.
Table 9.5 Transient vibration guide values for cosmetic damage to buildings
Type of Building
Peak component of particle velocity in frequency range of predominant pulse (SOAEL)
4Hz to 15Hz 15Hz and above
Reinforced or Framed structures
Industrial and heavy commercial buildings 50 mm/s at 4Hz and above
Unreinforced or light framed buildings
Residential or light commercial buildings
15 mm/s at 4Hz increasing to 20mm/s at 15 Hz
20 mm/s at 15Hz increasing to 50mm/s at 40Hz and above
NOTE 1: Values referred to are at the base of the building.
NOTE 2: For un-reinforced or light framed structures and residential or light commercial buildings, a maximum displacement of 0.6mm (zero to peak) is not to be exceeded.
Code of Best Practice for Demolition and Construction sites, Worcestershire Regulatory Services (WRS)
This document (WRS, 2011) aims to provide consultants and contractors with guidance of general requirements of construction noise and vibration under Section 60 of CoPA, BS 5228 Part 1 and 2 and Best Practicable Means defined in Section 72 of CoPA. It provides specific advice as to the application of standards, noise limits and reporting that Worcestershire Regulatory Services (WRS) will take into account in relation to construction noise and vibration assessments.
The normal working day hours for construction are defined between 09:00 to 17:00 hours.
For noise limits the document states that “The suitability of specific noise limits is highly dependent upon the individual situation. The factors to be considered include:
• The characteristics of the noise and its potential effect on the neighbours;
• baseline ambient noise levels; and,
• the nature and duration of the works
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Levels of 75 dB a working day over a 10-hour period are suggested as a general rule. WRS expects noise control to meet or reduce the average noise from the site to this level. In built up environment this is not always attainable, in which case Best Practicable Means must be applied to reduce noise and vibration as far as possible. As a guide, typical daytime levels for noisy temporary works at neighbouring premises usually lie in the range of 70 – 80 dB LAeq” (WRS, 2011).
Specific limits for vibration are not provided but the document states that all potential receptors and buildings should be considered with particular attention to: occupiers and users of buildings, hospitals or laboratories, IT related issues and cosmetic or structural damage to buildings or heritage sites.
9.5 Value (sensitivity) of Resource The identification of the value or sensitivity of each noise sensitive receptor in proximity to the construction works is set out in Table 9.6. This is based upon the guidance in HA205/08 (DMRB, 2008).
Table 9.6 Sensitivity and Value of Receptors.
Receptor Value (Sensitivity) Receptor Type Definition Location
Very High International designated area, Special cases for noise or vibration sensitivity
No receptors identified
High Residential, educational buildings, medical facilities
Dwellings on Bridge Street to the north of River Severn
Dwellings on Bromwich Road
Medium Hotel, Community Facilities and Places of worship
Premier Inn Hotel on New Road
Low Commercial buildings (e.g. offices) The Pavilion In The Park – Restaurant
Avis and Budget Car Hire Worcester – Offices
Negligible Farmland, Industrial premises No receptors identified
The distances between the receptors considered in this assessment and each of the proposed construction activities, organised in consecutive order, are presented in Table 9.7.
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Table 9.7 Distances between assessment receptors and construction activities
Construction Activity
Assessment Receptors – Distances (metres)
Dwellings on Bridge St
Dwellings on Bromwich Rd
Premier Inn Hotel on New Road
Commercial buildings
(Restaurant
and Offices)
Excavation Works 180 200 20 80
Round culvert inlet structure installation in Cripplegate Park.
275 260 115 80
Box culvert trenched installation under New Road from the culvert inlet to the playing fields (Kings School).
330 180 160 140
Raising of the road and the footway from the outside area of the Cricket Club to just past the main entrance.
200 200 10 80
Surfacing Works 180 200 20 80
Changes to the three splitter islands at junctions with Hylton Rd, North Parade & All Saints Rd.
10 - from either N Parade & All Saints Rd.
400 – Hylton Rd
35 - Hylton Rd 85
Tree removal on New Road & Hedgerow removal at Cripplegate Park gate.
155 180 10 105
9.6 Design and Mitigation The Best Practicable Means (as defined in s72 of the Control of Pollution Act 1974) are recommended for the contractor to implement in order to reduce noise levels arising during the construction period. Also, where practicable the control measures set out in BS 5228:2009+A1:2014 Part 1 will be implemented.
Best practice noise and vibration measures that could be adopted within a contractor’s Construction Environmental Management Plan (CEMP see Appendix 5.1), might include:
• Choice of methodology/technique for noisy operations will be considered in order to eliminate or reduce noise. Where reasonably practicable, fixed items of construction plant should be electrically powered in preference to diesel or petrol driven;
• Each item of plant used will comply with the noise limits quoted in the relevant European Commission Directive 2000/14/EC/United Kingdom Statutory Instrument (SI) 2001/1701;
• Equipment will be well-maintained and will be used in the mode of operation that minimises noise;
• Noisy plant will be kept as far away as possible from sensitive areas;
• Equipment will be shut down when not in use;
• Equipment fitted with enclosures shall be operated with such enclosures in place at all times;
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• Vehicles and mechanical plant employed for any activity associated with the construction works will, where reasonably practicable, be fitted with effective exhaust silencers and shall be maintained in good working order and operated in a manner such that noise emissions are controlled and limited as far as reasonably practicable;
• Machines and vehicles in intermittent use will be shut down or throttled down to a minimum during waiting periods;
• All employees shall be provided with an appropriate induction and ongoing briefings regarding the management of environmental issues;
• All materials will be handled in a manner that minimises noise;
• Where possible, mobile acoustic screens/barriers or enclosures will be placed around the most noisy equipment (such as the saw to cut concrete and the vibratory roller);
• No plant or material will be delivered or loaded during night-time;
• Mains electrical power will be used wherever possible;
• Employees must show consideration to the sensitive receptors, including residential neighbours and must not generate unnecessary noise when walking to and from the site, or when leaving and arriving at the works. This will be communicated through the site induction start of shift briefings and toolbox talks.
Mitigation through noise management should be implemented by informing all residents in the area about the schedule and duration of the works, including the programmed road closures. It is of high importance to inform the receptors at the hotel and the cricket ground conference facilities at an appropriate time in order to not interfere with their programmed activities.
It is recognized that noise from some of the activities would not be possible to be reduced to the recommended guideline through mitigation, in particular due to the distance between the Hotel receptor and construction activities. However, the noise from the activities will be temporary. Some activities can be controlled to some extent by the provision of temporary noise barriers, which may be expected to generate between 5 and 10dB attenuation, but this may not be practicable in all instances. However these activities are considered to be of temporary and short duration.
In order to mitigate the predicted SOAEL from vibratory compacting on any human receptors within the Premier Inn it is recommended that the owners of the Premier Inn are kept informed of works and the likely level of vibration.
9.7 Magnitude of Impacts
9.7.1 Construction Noise Impacts The calculation methodology set out in BS 5228: Part 1: 2009 has been used to estimate the noise level from each of the proposed activities at the nearest sensitive receptors identified in Table 9.6. The distances between the receptors and proposed activities considered are those indicated in Table 9.7. Table 9.8 below shows the calculation results.
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Table 9.8 Calculation Results
Construction Activity
Calculated Impact at 1m from the receptor façade, LAeq, 9hr-daytime (dB)
Exceedances predicted to be above the SOAEL threshold for daytime (75dB SOAEL), defined in Policy terms, have been highlighted in Table 9.8. These include changes in the splitter islands close to the dwellings on Bridge Street (i.e. at North Parade and All Saints Road) and four of the construction activities at the Premier Inn Hotel due to its proximity to the works.
The calculated noise levels are then compared for noise change against the existing noise level in order to assess the absolute impact against the thresholds. This is presented in Table 9.9.
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Table 9.9 Increase in Noise Levels as a result of Construction Works and Impact Significance.
Construction Activity Increase over the
Existing noise Level (dBA)
Sensitivity of Receptor (Table
9.6)
Impact Magnitude (Table 9.1)
Impact Significance (Table 9.2)
Dwellings on Bridge St – Existing noise level assumed to be 70dBA daytime
Excavation Works 0.1
High
Negligible Slight
Round culvert installation 0.0 No Change Neutral
Box culvert installation 0.0 No Change Neutral
Road raising 0.1 Negligible Slight
Surfacing Works 0.5 Negligible Slight
Changes at Splitter islands 17.4 Major Large
Tree & Hedgerow removal 1.3 Minor Slight
Dwellings on Bromwich Rd – Existing noise level assumed to be 70dBA daytime
Excavation Works 0.1
High
Negligible Slight
Round culvert installation 0.0 No Change Neutral
Box culvert installation 0.1 Negligible Slight
Road raising 0.1 Negligible Slight
Surfacing Works 0.4 Negligible Slight
Changes at Splitter islands 0.1 Negligible Slight
Tree & Hedgerow removal 1.0 Minor Slight
Premier Inn Hotel on New Road – Existing noise level assumed to be 70dBA daytime
Excavation Works 5.3
Medium
Major Large
Round culvert installation 0.2 Negligible Neutral
Box culvert installation 0.1 Negligible Neutral
Road raising 7.2 Major Large
Surfacing Works 10.0 Major Large
Changes at Splitter islands 7.3 Major Large
Tree & Hedgerow removal 19.5 Major Large
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Premier Inn Hotel on New Road – Existing noise level assumed to be 70dBA daytime
Excavation Works 0.5
Low
Negligible Neutral
Round culvert installation 0.3 Negligible Neutral
Box culvert installation 0.1 Negligible Neutral
Road raising 0.2 Negligible Neutral
Surfacing Works 1.5 Minor Neutral
Changes at Splitter islands 1.9 Minor Neutral
Tree & Hedgerow removal 1.9 Minor Neutral
The predictions of ‘total noise’ from construction, including the existing noise level have been compared, in Table 9.10, to the magnitude and significance criteria from HD213/11 in terms of Environmental Assessments guidance. The reported calculation results have revealed that the proposed works have the potential to have a ‘Large’ significance at the Hotel receptor during the initial excavation works, surfacing works, road raising, changes at Hylton Road splitter island and tree removal activities. While at the residential receptors only the works during the changes at the splitter island on North Parade and All Saints Road will affect dwellings on Bridge Street with a ‘Large’ significant impact expected.
9.7.2 Construction Vibration Impacts There are no British Standards that provide a method to predict levels of vibration from construction activities, other than that contained within BS 5228-2 (BSI, 2014v), which relates to percussive or vibratory piling only. It is generally accepted that for the majority of people, vibration levels in excess of 0.3 mms-1 PPV are just perceptible.
The item of plant likely to produce the highest levels of vibration is the vibratory roller used for compaction. This would be used during the activities of ‘box culvert installation’ and ‘road raising’. BS 5228-2 provides a method to calculate the level of vibration from ‘vibratory compaction’.
The formulae provided in BS 5228-2 (BSI, 2014v) is:
𝑉𝑟𝑒𝑠 (𝑃𝑃𝑉) = 𝐾𝑠√𝑛𝑑 [𝐴
𝑥 + 𝐿𝑑]
For the items of plant likely to be used, the input parameters and the resultant estimated PPV level are shown in Table 9.10.
Table 9.10 Vibration prediction input parameters
Parameter Variable Input Definition
𝐾𝑠 75 scaling Factor (50% probability of predicted value being exceeded)
𝑛𝑑 1 number of vibrating drums
𝐴 1.60 maximum amplitude of drum vibration (mm)
𝑥 10 distance to receptor (m)
𝐿𝑑 1.2 width of vibrating roller drum (m)
𝑽𝒓𝒆𝒔 (𝑷𝑷𝑽) 4.0 resultant PPV for steady state, in millimeters per second (mm/s)
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The closest distance that the vibratory compactor is likely to be from the Premier Inn is 10m. At this distance, the predicted level of vibration is 4.0 mm/s which is above that identified as the SOAEL for human receptors. This is likely to cause complaint if the receptors are unaware of the possibility of this level of vibration.
A level for adverse effect cannot be set for the building since this is not a human receptor. However, examining the levels in Table 9.5 it can be seen that the lowest level where damage may occur to buildings is 15mm/s. The predicted level of 4.0 mm/s is below this and therefore no damage to the Premier Inn, even cosmetic, would be expected. This also applies for the commercial buildings that are located at a greater distance from the works than the Hotel is.
At more than 30m from the vibratory compaction the predicted level is below 1 mm/s, which is the level set as the LOAEL for human receptors. Apart from the Premier Inn, there are no other receptors within 30m of the vibratory compacting.
Attention needs to be drawn to the Noise Control Technical Guidance produced by Worcestershire Regulatory Services (WRS, 2015) where it states “In circumstances where vibration is a potential source of disturbance it is expected that an appropriate vibration survey or prediction be carried out. Initially, to avoid complex investigations being carried out unnecessarily a screening survey should be carried out. If monitored vibration levels do not exceed 0.14 mm/s peak particle velocity in any axis then no further survey is necessary. If this level is exceeded then it is expected that an assessment would be carried out with reference to BS6472. Where re-radiated noise is a potential problem then this should also be assessed. Data from these assessments should be made available to WRS for consideration”.
9.8 Significant Effects It is not anticipated that there will be any significant effects upon noise and vibration levels as a result of the scheme, provided that the mitigation measures presented in Section 9.6 and Best Practicable Means are implemented on site during the construction activities.
9.9 Indication of Difficulties Encountered The baseline existing noise levels at the site have not been monitored but the acoustic environment is considered to be dominated by transportation noise sources and human activities typical of the site (i.e. mixed commercial and residential site in an urban area). The Noise and Vibration scoping report information from Defra’s strategic-level noise maps of the road network provides a desk based study approach to quantify the noise climate in the area surrounding the A44. This indicates that the daytime noise level (LAeq, 16h) at the closest receptors on A44 is between 70 and 75 dB (A) (Extrium, 2015). Although this appears to be a very high noise level, for the purpose of the assessment a 70dB existing noise level has been considered where there is not any other source of existing noise data.
Appendix 9.1 includes the plant lists for the proposed construction works where it should be noted that these are indicative at present based upon experience of similar type of works. But it is considered this list is close to the actual equipment the contractor will employ on site.
The formula employed to calculate steady state vibration from a vibratory roller during the construction activities that require compaction is a derived empirical formula that enables a prediction to be made of resultant PPV and for the purpose of this assessment it provides an indicator of the probability of a threshold level being exceeded. However this could deviate from the actual on site vibration level so monitoring is recommended to further investigate the vibration level to be expected.
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9.10 Summary The assessment of construction noise and vibration impacts from the proposed works at A44 New Road has shown that:
• In terms of government policy, based on the ABC Method set out in BS 5228-1:2009 + A1:2014, the proposed works will exceed the 75 dB(A) daytime SOAEL threshold, without mitigation. These will occur at the residential receptors on Bridge Street during the change of splitter island works at both North Parade & All Saints. At the Hotel receptor the exceedance will occur during the surfacing works, changes at the splitter island on Hylton Road and tree and Hedgerow removal activities.
• In terms of environmental impact, the calculated noise changes, based on HD213/11 magnitude and significance criteria will result in a Large Impact during the same activities exceeding the SOAEL above, without mitigation. However, these activities are likely to be of temporary duration only.
• The vibration from the vibratory compactor is likely to be noticeable to human receptors within the Premier Inn. However, this will not be at a level where building damage, even cosmetic, is expected.
It is anticipated that with Best Practicable Means implemented on site during the construction activities, the works should be capable of being undertaken without the need to recourse to Noise Insulation or Temporary Rehousing measures. Due to the schedule and duration of the proposed construction activities to be only during day time and weekdays, the impact is deemed to be of temporary duration.
