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MONITORING AND MAPPING OF ENVIRONMENTAL NOISE

CHAPTER TWO DRAFT DIRECTIVE INPUT DATA REQUIREMENTS AND IDENTIFICATION OF ORGANISATIONS AND AGENCIES TO BE CONTACTED

DRAFT EC DIRECTIVE ON ENVIRONMENTAL NOISE

2.1 The proposed Directive entitled Assessment and Management of Environmental Noise requires Member States to undertake mapping of environmental noise, and it is understood that the Directive will come into force sometime in 2002, although there is doubt at present over when mapping will have to be carried out under the terms of the Directive.

2.2 Article 5 of the Directive states that the maps will be produced in terms of the noise indicators L _den and L _night.

2.3 Article 5 further states that " Until the use of common assessment methods for the determination of L _den and L _night is made obligatory, existing national noise indicators and related data may be used by Member States for this purpose and should be converted into the indicators mentioned above. These data must not be more than three years old."

2.4 Supplementary noise indicators may be used for special cases (as listed in Annex I of the directive). For acoustical planning and noise zoning, Member States may use other noise indicators than L _den and L _night.

2.5 There is a requirement for Member States to communicate information to the Commission on any relevant limit values in force within their territories or under preparation, expressed in terms of L _den and L _night and where appropriate, L _day and L _evening, for road traffic noise, rail traffic noise, aircraft noise around airports and noise on industrial activity sites, together with explanations about the implementation of the limit values.

2.6 The EC Directive will require maps of urban areas, known as agglomerations, and major roads, railways and airports outwith agglomerations. Within agglomerations, in addition to transportation noise, the maps will also have to include major industrial sites. Maps illustrating the agglomerations of 250,000 and 100,000 have been produced and are included as Annex 1.

DATA REQUIREMENTS

2.7 Data must be obtained to identify the location and characteristics of noise sources, i.e. roads and rail network; and the location of acoustically significant features i.e. barriers, cuttings and soft ground.

2.8 Data can be regarded in two elements:

• Map data (topological and topographic)
• Attribute data

Map Data

2.9 Map data is essential to identify the geographical location of objects and features to be included in the modelling assessment. This map data must be 'captured' digitally as either points, lines or polygons. It is essential to capture map data with high degree of positional accuracy, therefore an understanding of digitising error from source mapping or imagery of different scales is required. Consider by means of an example Figure 2.1 that shows a model with 3 layers. The first is a point layer representing customers; the second is a polygon layer representing buildings; whilst the third is a line layer representing roads.

Figure 2.1: Conceptual diagram of digital map data ¹

¹ Copyright ESRI

2.10 The co-ordinate system for each layer is carefully designed so that when combined they fall into alignment. This is known as geo-referencing. In the example above, a customer point will fall within the relevant building polygon, which in turn will be located adjacent to the correct street.

Accuracy of Data for Noise Models

2.11 It is essential to capture map data with high degree of positional accuracy, therefore an understanding of digitising error from source mapping or imagery of different scales is required. Digitising pucks often have a tolerance of up to +/- 2mm. When this tolerance is considered in conjunction with the scale of the original source mapping i.e. aerial photography, the potential error in positional accuracy of the digital data can be estimated. It therefore follows that a 2mm digitising error for data captured from a satellite image of 1:250,000 scale equates to a real world positional accuracy error of +/- 500m, whereas the same error for data captured from an aerial photograph of 1:1250 equates to +/- 2.5m. An understanding of the spatial sensitivity of the propagation characteristics of noise indicates that sources, barriers or receptors positioned inaccurately may significantly reduce the validity of any mapping exercise and subsequent population assessment.

Sources of Data

2.12 The principle source of map data for the current project is the Ordnance Survey digital data products, provided under licence by the Scottish Executive (SEGIS unit). In addition the Scottish Executive have captured data for their own purposes. This is especially true for classified data relating to land use. The digital data held by SEGIS are documented in a SEGIS metadata database. These additional databases are also georeferenced to the British National Grid and derived from OS products.

2.13 The specification chosen for the mapping exercise will to a large extent dictate which data products are suitable to use. At the time of writing this report, building height data was not readily commercially available. The issue of building height data is discussed in further detail in chapter 3.

Data Products - General

2.14 Examples of map data products required for mapping in general are as detailed below and an explanatory note on each is provided.

• OS Landline
• OS MasterMap
• OS Landform Profile & PANORAMA
• Ariel Photography
• OSCAR
• Industrial locations
• Sea Ports
• Building Heights
• Soft ground
• Address Point
• Census Enumeration Data
• Postcode Unit

2.15 OS Land-Line is required to identify the precise location of road centre lines, rail tracks, some cuttings, building outlines and just about any other outlined feature visible from aerial photos. Features hidden from air are often not included i.e underpasses or tunnels.

2.16 There are three limitations with Land-Line. Firstly, it does not represent real world features as individual objects. It contains only outlines, therefore a house will be comprised of 1 or more lines which appear to join at the corners. In order to 'close ' the building lines and form a building, a polygon closing algorithm must be run on the data. This can be done in GIS or through some of the noise propagation tools, however it is notoriously inaccurate and validation and correction of data is time consuming. Any building other than a 4 sided detached house tends to run the risk of being deformed. Secondly, as it does not represent features as single objects it is not possible to join attribute data to buildings although this can be done for road centre lines and rail lines. Thirdly, it is understood by Casella Stanger that OS want to phase it out and OS have indicated they will give 1 years notice to do so. A national mapping exercise may last longer than 1 year, consequently this is potentially a serious issue for the SEGIS to consider.

2.17 OS MasterMap is a new product released recently and designed to be the eventual replacement of OS Landline. It is the exact opposite in that it represents all features as single objects i.e. representing buildings as discreet polygons. OS MasterMap is supplied in GML format that is not currently read by noise modelling software. Consideration should be given to the supply format of this product. While it is ideal for buildings it is of no use for road centre lines, as roads are not incorporated as a layer at present.

2.18 OS Landform Profile & PANORAMA are Digital Terrain Models (DTM's). They come in either grid points with heights or as interpolated contour lines. Some models import DTM data as either points or as contour lines, as is the case with the modelling package used in this case, Cadna.

2.19 Aerial Photography is useful for identifying acoustically significant features i.e. cuttings, bridge material for Calculation of Rail Noise prediction methodology or for assessing the number of carriageways on a road. OS can provide aerial photography, alternatively companies like Geoinformation Group and UK Perspectives are currently undertaking UK wide aerial photo flights to make AP available in digital format. Distribution of such products to contractors is often restricted.

2.20 OSCAR is a road centre line based data product with attributes identifying road classification and name. The centre lines do not always follow the exact location of the road centre as the data is captured from a variety of base mapping. It is necessary to clean OSCAR data where the road centre lines diverge significantly in their positional accuracy. In addition the identification of road sections for the purpose of joining attribute data could be aided by a more systematic method of identification.

2.21 Industrial locations in terms of the Directive are likely to be defined as premises regulated by Integrated Pollution Control (IPC), Local Authority Pollution Control (LAPC) or Integrated Pollution Prevention Control (IPPC), although there is an issue regarding the potential omission of industrial sources such as quarries, mines, railway shunting yards and maintenance depots, motorway service areas etc which do not fall clearly into any category defined within the directive.

2.22 Sea Ports charts showing shipping routes.

2.23 Building Heights data will eventually be attributed to MasterMap data, although there are no time scales at present for this. Remote sensing technologies are being used to slowly capture building heights. Geoinformation Group can provide building height data on OS Land-line however this product will be obsolete in 1 year and the data will not be compatible with MasterMap.

2.24 There are a number of land cover databases available, but none of these have much in the way of intra urban resolution. It is also possible to obtain the data by means of field studies, but on a national scale this is likely to be impracticable.

2.25 Address Point data is of use in identifying receptor locations although some locations are inaccurately represented e.g. PO boxes and institutional locations.

2.26 Census Enumeration Data is necessary to estimate the total number of people residing by polygon.

2.27 Postcode Unit data enables attributed polygons and can be linked with census data and buildings to produce receptor density maps.

2.28 Stuart Gardner of Scottish Executive GIS group (SEGIS) was contacted in order to obtain mapping products under licence from the Scottish Executive. Landline files are available at various scales 1:1,250 being suitable for urban areas (1/2 km tile) 1:2,500 for rural areas and 1:10,000 for mountain and moorland areas. The study area is densely built up and so the following products were requested.

• Panorama (contour files) in arc view format for the study area
• Landline (1:1,250) urban area
• 1:10k b&w or colour raster files
• Building classifications and building height data
• Land use data

Attribute Data

2.29 The Attribute Data identified as being required for the present commission is as follows:

• Road traffic data
• Rail movement data from SRA/Railtrack
• Aviation data - for discreet receptor points on a 10m x 10m grid, from CAA
• Industrial process - operating hours and type of process
• Sea Port data - frequency and type of shipping movements

2.30 The predictions for all noise sources must be based on the same year. Consequently, it shall be necessary to factor-up any aged data to this year. Any such factors shall be based on high growth.

2.31 The format of the data required was determined by the guidance currently used to obtain existing national noise indicators, as required by the draft Directive (paragraph 2.3).

2.32 All data suppliers were asked how their data was stored and whether they used a GIS system to store the data however at the time of enquiry, no data provider was able to supply data linked to a GIS.

Road Traffic Data

2.33 The L _{A10, 18 hour} parameter is the accepted parameter for UK road traffic noise assessment. This is the noise level exceeded for 10% of the time over an 18 hour period from 06.00 to 24.00 hours.

2.34 The current UK prediction method, the Calculation of Road Traffic Noise 1988 (CRTN88) will be the basis of road traffic mapping but with correction factors applied to the 18-hour L _A10 predicted level to estimate the period L _Aeq levels that are necessary to generate the L _den parameter. As a consequence, the data input requirements are those set out in CRTN88. These are described in more detail below.

Segmenting Road Links

2.35 It is expected that many roads may need to be sub-divided into segments, so that changes in traffic variables (e.g. where flows differ significantly either side of a junction), road gradient and curvature or due to progressive variation in screening can be taken into account. The segments should be given start and end identifiers. The tagging of all data to identify its origin is of paramount importance. Consideration of the data format is outwith the scope of this project.

Responsibility for Gathering the Data

2.36 If mapping is to be undertaken by mapping contractors it shall be the responsibility of the mapping contractor to obtain all the road traffic input data described in this section from the appropriate source. However, given that the road attribute data is principally held by two organisations; the Scottish Executive and the second, the local authorities, there is the issue of both organisations having the data readily available in a format required by the mapping contractor and with adequate licence provision to allow third parties to use the data in noise mapping.

2.37 Mr David Brown and Mr Stuart Hay of the Scottish Executive Roads Network Management and Maintenance Division manage the SRTD database which contains the data collected for national traffic surveys. These data range from one-off manual classified counts and part time automatic volumetric counts up to full-time automatic classified counts going back over a number of years. All of this traffic count information is associated with a link-based network covering all motorway, trunk, and some principal roads.

2.38 The local authority of concern for this project is Renfrewshire Council. Mr Iain Hamilton and Mr Stuart Rankin of Renfrewshire Council Roads Department were contacted regarding non-trunk road traffic flow data.

Road Traffic Flows

2.39 The Directive provides a definition of major roads: in the first wave of mapping, regional, national or international roads that have more than 6 million vehicle passages per year will require mapping. This equates to an Annual Average Daily Traffic (AADT) flow of 16,438. Hence, for the purposes of this mapping exercise, a major road shall be defined as one carrying an AADT of 16,438 or more and a minor road as one carrying an AADT of up to 16,437.

2.40 For all major and minor roads so defined, the Annual Average Daily Traffic (AADT) flow should be obtained for the base year. This data should ideally be provided for each hour within the 24-hour period. From this data, the 18-hour flow to be used in the road traffic noise prediction model can be determined. Any roads with an 18-hour AADT flow of less than 1000 vehicles should be ignored (this is the threshold below which the CRTN88 prediction method is invalid).

2.41 If the hourly flows are not available, the traffic volume over the 18-hour period (06:00 to 24:00 hours) should be obtained for direct inclusion into the road traffic noise prediction model.

Incomplete Road Traffic Flows

2.42 If hourly and 18-hour flows are not obtainable, then any available road traffic data for the link in question should be gathered, for example, peak hour data or 12-hour data (07:00-19:00 hours). It will then be necessary to estimate the 18-hour flow, and to this end, the Scottish Executive/Local Authority will provide, a set of factors depending on road type, identifying the proportion of total traffic within each individual hour within the 24-hour period. Given this hourly breakdown, it will be possible to determine a relationship between the 18-hour period and the period for which data is available.

Missing Road Traffic Flows

2.43 If no flows are available, then the Scottish Executive/Local Authority and the Mapping Contractor should collaborate to estimate the 18-hour flow for inclusion in the road traffic noise prediction model. Such an estimate would need to consider: the type and designation of the road; the flows on nearby and adjoining roads; whether the road is a known 'rat-run'; and the density of housing and/or commercial/industrial areas through which the road passes and thus serves.

Dual Carriageways

2.44 For normal roads, the flow of traffic in both directions shall be aggregated to obtain the total flow. In cases where the two carriageways are separated by more than 5 metres or where the heights of the outer edges of the two carriageways differ by more than 1 metre, the two carriageways shall be treated separately and the traffic flows disaggregated accordingly.

Bus Lanes

2.45 Bus lanes should be considered separately wherever their period of operation covers at least the 18-hour period (06:00 to 24:00 hours). In this case the number of bus movements within that period should be identified separately from the other traffic using the remaining traffic lane(s). If a bus lane operates for only part of the 18-hour period, the bus lane should be treated as part of the general highway and the bus movements aggregated into the overall traffic flow.

Vehicle Speed and Proportion of Heavy Goods Vehicles

2.46 In line with the vehicle flow data obtained for each road link as described above, the proportion of heavy goods vehicles and the vehicle speed should also be obtained.

2.47 In this respect the definition of a heavy goods vehicle would be where the unladen weight exceeds 1525 kg.

2.48 The traffic speed to be used in the calculation process depends on whether the road is level or on a gradient.

2.49 For level roads the traffic speed to be used depends on the speed limit and road classification as set out in Table 2.1 which follows, itself taken from the Calculation of Road Traffic Noise (CRTN88).

Table 2.1: Level Road Traffic Speeds (CRTN88)

2.50 For roads with a gradient, the traffic speeds should be calculated in the same way as for level roads, but a correction factor applied to reduce the speed in accordance with CRTN88. The reduction in speed depends on the percentage gradient (G) and the percentage of heavy vehicles (p) is taken from Chart 5 of CRTN88 and is as follows:

Reduction in speed = { 0.73 + [ ( 2.3 - ( ( 1.15 * p ) / 100 ) ) * ( p / 100 ) ] } * G

In the case where carriageways are treated separately or for one way traffic schemes, the speed correction should not be applied to the downward flow.

2.51 The method for determining traffic speed described above should not be used when other available data, based on particular local conditions, indicate a traffic speed significantly different from the prescribed mean speed for the type of road. In this case the Scottish Executives or local authority's estimate or measurement of speed shall be used.

2.52 In order to take account of the effect of different road surfaces on the noise level generated, it will be necessary to determine whether the surface of each road link is:

• pervious or impervious
• concrete or bituminous
• and, if the traffic speed is at or above 75kph, the texture depth (measured by the sand-patch test)

2.53 For road texture depth Mr Willie Grant, also of the Scottish Executive Roads Network Management and Maintenance Division was contacted and also Mr Stuart Rankin at Renfrewshire Council.

2.54 STANGER have requested that data be supplied for all roads with an Annual Average Daily Traffic Flow of 4,000 or more. STANGER requested that the data would be supplied in the format shown in Table 2.2.

Table 2.2: Road Traffic Input Data

2.55 Organisations responsible for road maintenance ' operating companies', may be able to provide information on road levels. In the case of the study area, the ' operating company' who was contacted was ' Amey'. At the time of writing the ' operating companies' were unable to provide the required information.

Rail movement data from Railtrack

2.56 The prediction method employed to assess railway noise is the 'Calculation of Railway Noise 1995' (CRN95). As a consequence, the data input requirements are those set out in CRN95. These are described in more detail below.

2.57 This method generates noise levels in terms of the equivalent continuous noise level (L _Aeq). In order to enable an assessment against the requirements of the Noise Insulation (Railway and Other Guided Transport System) Regulations 1996, the CRN95 method includes formulae to generate a period L _Aeq over 6 hours (00:00 - 06:00 hours) and 18 hours (06:00 - 24:00 hours). However, it is relatively straightforward to calculate the L _Aeq over other periods providing the train movements for those periods are used as a basis. Because of the requirement to calculate the L _den parameter, it will be necessary to gather the rail input data for each of the following periods.

• Day 12 hour period from 07:00 to 19:00 hours
• Evening for the 4 hour period from 19:00 to 23:00 hours
• Night for the 8 hour period from 23:00 to 07:00 hours

2.58 It shall be the responsibility of the mapping contractor to obtain all the rail input data described in this section from the appropriate source. For railway tracks that are the responsibility of Railtrack, relevant data on the type and number of trains should already have been gathered by the Project Manager. For all other data, the mapping contractor should approach the appropriate body, for example, the railway or light rail/tram operator. There is also the issue of the rail operators having the data readily available in a format required by mapping contractor.

2.59 For the purposes of the first wave of mapping, the Directive defines a major railway as having more than 60,000 train passages per year. This equates to an average of 164 train movements each day based on a seven day week. Hence, for the purposes of this mapping exercise, a major railway shall be defined as one carrying a daily average of 164 train movements or more and a minor railway as one carrying a daily average of up to 163 train movements. Any rail tracks where there are less than 10 train movements should be ignored.

2.60 The CRN95 methodology requires the Sound Exposure Level (SEL ref) dB(A) for different train types using a segment of track to be determined. Consequently, for each of the three time periods specified above, it is necessary to determine the type of railway vehicles running on each stretch of track, the number of railway vehicles within each train unit and the number and speed of each train.

2.61 For calculation purposes, a railway vehicle is either a coach, in the case of a passenger train, or a wagon, when a freight train is considered. In some cases trains will comprise a mixture of railway vehicles with different noise characteristics. In order to account for this in the calculation procedure consideration shall need to be given to dividing the train into two or more trains. Locomotives (diesel or electric) should also be treated as a separate train in the calculation and, therefore, they should be identified separately when gathering the source data. Furthermore, information on the noise from locomotives is given for both steady speed running and, for diesel locomotives, for full engine power operations. Hence, track segments where a diesel locomotive is either accelerating or is on a segment where it is expected to operate under full power, should be identified.

2.62 The train speed used in the calculation may depend upon such factors as the track type, gradient, track curvature, the signalling system, scheduling requirements of the operator and the speed limit that is in force for the track segment. In some cases it will be appropriate to use the maximum permissible speed for a segment or the maximum attainable or permissible speed for the train type in question. However, train speeds dictated by the local conditions or set by the operator will determine the choice of speed for each train type in most cases. For locomotives accelerating under full power either from rest or from an initial low steady speed, the speed used in determining the reference noise level shall be the average speed over the segment.

2.63 Where Railtrack or the system operator are unable to provide data on train types this information may be gathered by manual counts.

2.64 Various factors may augment the rolling noise levels as trains pass over different types of track or structures such as bridges. CRN95 provides corrections to rolling noise for various different track and track support structures as indicated below and so it shall be necessary to identify where these exist. This information may be gathered from a variety of sources: site-walkovers, maps and plans or perhaps direct from Railtrack.

• Jointed track
• Points and crossings
• Slab track
• Concrete bridges and viaducts
• Steel bridges
• Box girder bridges

2.65 Ms Dorothy Fenwick (Head of Corporate Affairs) and Ms Kirsty Young of Railtrack were contacted in order to establish the availability of rail traffic data. Due to the large amount of information required a meeting was proposed to discuss availability. STANGER met with Ms Kirsty Young on 15 January 2002 at which she provided the data requested. The data supplied will be discussed in section 3.

2.66 For the CRN95 assessment the following data was requested:

• Routes with 60,000 trains or more to identify the major railway tracks
• Passenger service database information on timetables, engine and carriage types and train length/number of carriages, train speed
• Freight cargo train routes, engine and wagon types and train length/number of wagons, train speed
• Track information (track state, track gradients, refuges (passing loops))
• Information on the ground levels of embankments/cuts/lines
• Information on engineering works.

2.67 A preliminary data input proforma was devised for the rail information provider as follows in Table 2.3.

Table 2.3: Railway Input Data

Aircraft Attribute data

2.68 The accepted parameters for UK aircraft noise assessment are L _{Aeq, 16 hour} and L _{Aeq, 8 hour}. These are the equivalent steady sound levels for the 16 hour period between 07.00 to 23.00 hours and the 8 hour period from 23.00 to 07.00 hours, respectively. The prediction method employed to obtain the L _{Aeq, 16 hour} and L _{Aeq, 8 hour} is given in British Standard 5727 1979 (ISO 3891 1978) 'Method for describing aircraft noise heard on the ground'.

2.69 All major airports will generate their own contours. Usually aircraft noise is modelled for planning purposes and sometimes the requirement to produce aircraft noise contours is a condition of the planning consent. The minor airports may generate their own contours. Where they do, the mapping consultant should obtain these direct from the airport. Where the airports do not generate their own contours it would be the responsibility of the mapping consultant to predict contours.

2.70 The following data is required for the prediction of aircraft noise:

• Aircraft Standard Instrument Departure routes (SID's)
• Number and type of aircraft on each route
• Runway operations

2.71 Prediction of aircraft noise is complex and is usually undertaken using computer models such as INM (US Federal Aviation Authority), or by the Civil Aviation Authority (CAA) using their 'in-house' model, ANCON. In order to use existing aircraft noise models the data would require to be no more than 3 years old (paragraph 2.3).

2.72 Glasgow International Airport lies at the north west of the study area, and the British Airport Authority (BAA) have a statutory requirement to produce noise contours for this airport. Other Scottish Airports are not required to produce noise contours although contours have been produced for Edinburgh and Aberdeen Airports.

2.73 Mr Roddy Yarr, Environmental Manager with BAA at Glasgow International Airport, was contacted in order to obtain information on the noise contours for Glasgow Airport. He informed us that the BAA commission the Civil Aviation Authority (CAA) to prepare contours every 4 years and the last contours were produced in 2000. Mr Yarr referred STANGER to his contact at the CAA, Mr Joseph Lee.

2.74 In order to create noise contours, most noise prediction software tools create a grid of receptor point values from which the contours are interpolated. In order to be able to sum all noise sources, to predict a total noise level from all sources at a given location, it is necessary to have predicted noise levels at precise locations. It is proposed to predict noise levels for a receptor grid with 10m x 10m spacing, with the precise geographic location of the receptor grid points being defined as every tenth metre of the British National Grid i.e. for eastings 248500, 248510, 248520, etc..

2.75 STANGER therefore requested the predicted levels for the area of Renfrew, British National Grid X coordinates 248500 to 252500 and Y coordinates 663500 to 667500, 10m x 10m spacing for every tenth metre of the British National Grid i.e. for eastings 248500, 248510, 248520, etc..

2.76 If the grid point values are not obtainable an alternative method would be to use contour polygons representing the area between noise class intervals i.e. 50-53dB, 53-56dB, etc.. It would be possible to use GIS to derive a value for each grid point where it coincides with a contour polygon i.e. from the 50-53dB class we would attribute the coinciding receptor points with a value of 51.5dB, or interpolate between the contour lines to derive grid point values on 10m grid.

2.77 For smaller airports such as Dundee and Inverness it would be necessary to obtain air traffic movement data in order to model the aircraft noise, as discussed in paragraph 2.68.

Industrial process - operating hours and type of process

2.78 The accepted parameter for UK industrial noise assessment is L _{Aeq, T} which is the equivalent steady sound levels for the relevant time period. In some instances the L _{Aeq, T} would require a character correction to be applied to give a rated noise level L _Ar,T.

2.79 There is at present no UK definitive definition of what will constitute industrial noise. However, it is likely that it will be those activities registered as Part A and/or Part B Processes as defined within the EC Directive 96/61/EEC concerning Integrated Pollution Prevention and Control (IPPC). This Directive presents a regulatory system that aims to employ an integrated approach to control the environmental impact of certain industrial activities through a single permitting process. Implementation of IPPC takes place in accordance with the Pollution Prevention and Control (Scotland) Regulations 2000, made under the Pollution Prevention and Control Act 1999.

2.80 Assessment of Part A and B processes alone would mean that many 'industrial sources' type noise sources would be omitted, examples would be mines, quarries, railway shunting yards and maintenance depots, motorway service areas, bus depots etc.

2.81 A variety of prediction methods may be used for prediction industrial noise sources, depending on the noise source. Method of establishing a rated noise level for an industrial noise sources is that contained within British Standard 4142: 1997 'Method for rating industrial noise affecting mixed residential an industrial areas' and British Standard 5228: Part 1 (1997) 'Noise Control on Construction and Open Sites' (for assessment of quarry noise).

2.82 There be many noise sources at each 'industrial' source location. The sources may be modelled individually or the 'industrial' source area may be assigned a single sound power level.

2.83 STANGER contacted the Scottish Environmental Protection Agency (SEPA) to request information from the Part A and B registers. Mr David Paris at Renfrewshire Council Environmental Health Department was also contacted regarding local knowledge of industries operating within the study area which would not be on the SEPA register.

Sea Port data - frequency and type of shipping movements

2.84 Noise from this transportation source would in the main arise from onshore facilities: dockside operations, container yards and vehicle movements associated with container distribution. This would be assessed as an industrial noise source for which the accepted parameter for UK industrial noise assessment is L _{Aeq, T} which is the equivalent steady sound levels for the relevant time period. As discussed previously in some instances the L _{Aeq, T} would require a character correction to be applied to give a rated noise level L _Ar,T. The method of establishing a rated noise level for an industrial noise sources is that contained within British Standard 4142: 1997 'Method for rating industrial noise affecting mixed residential an industrial areas'.

2.85 The Sea Port attribute data is available from the Port Authorities. For the study area the relevant authority is Clydeport. Mr Peter Somerville at Clydeport Operations Greenock and Mr Andrew Hemphill at Clydeport Glasgow were contacted.

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