APPENDIX C - ENVIRONMENTAL APPRAISAL METHODOLOGY

• Consultation with local planning authorities to identify nearby AQMAs and monitoring locations
• Production of constraints maps showing properties within 200m of the scheme, and a property count in four distance bands
• Estimation of pollution concentrations at properties most likely to be affected by the proposals and identification of areas which will experience an improvement or deterioration in air quality.
• Estimation of the overall change in peoples exposure to pollution concentrations.

• Consultation with statutory bodies and local planning authorities
• Desk based assessment of the study area
• Comments from officers from statutory bodies on the implications of route options

HS would be happy with any sub-option which had no more impact on Orrock House than the route agreed in 1996.

AC would look unfavourably on any sub-option that would sever Menie House from the gatehouse

• Estimate of the number of properties within 100m of each possible route option, highlighting particularly sensitive properties
• Note any areas or features of ecological/archaeological value within 100m
• Note any significant difference in magnitude of disruption between route options
• Statement of any significant difference between the borrow or surplus material needs of possible route options

Property estimates are included in Appendix B: Environmental Appraisal Table. The counts include properties common to all routes

Covered in appropriate sections

Sub-option’s 1, 2 and 3 may require additional vehicle movement to dispose of excess cut material. Sub-option 5 provides best earthworks balance thus reducing vehicular movements.

• Consultation with statutory bodies and local planning authorities
• Desk based assessment of the study area
• Protected species surveys and breeding bird survey
• Walkover of route corridor
• Comments from officers from statutory bodies on the implications of route options

Comments from SNH the same for all sub-options

• Consultation with statutory bodies and local planning authority
• Re-evaluation of previous Stage 2 landscape assessment
• Desk study
• Walkover survey of route corridor
• Appraisal of landscape and visual effects of route options

Walk-over focussed on the differences between the route sub-options

• Identify the type and number of properties which might need to be demolished
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• Estimate (for each route option) the number of residential, commercial (including farming), industrial and other properties at risk of demolition or land take.
• Identify the location, status and importance of land used by the public which could be lost
• Identify areas of land which fall within local planning authority development designations
• Agricultural land take for all options
• Effect on farm units for all options
• Annotated land use map
• Identify impact of each route option on un-navigable, disused or abandoned waterways present or developed
• Map showing waterways

None

Sub-option 3 in close proximity to one property, ‘Seaview’

No parks or recreation grounds affected, however informal footpaths and bridleways may be affected.

There are no major water bodies or rivers, the majority of the watercourses within the study area are small burns and drain eastwards towards the coast. Those in the north drain to the Ythan which is designated for its European nature conservation interests

An assessment was undertaken in general accordance with DMRB Stage 2. Given the similarities of the proposed sub-options and the project specifics (e.g. common junction designs and common start and finish points for the scheme), the adopted assessment method was based on DMRB Stage 2 but tailored to highlight the differences in noise impact that would result from each sub-option and facilitate direct comparison.

The following methodology was adopted:

• Between the common start and finish points for each sub-option, road traffic routes/route sections subject to re-alignment (including both the A90 and local side roads) were identified.
• Proposed new road links / sections (including both the A90 and local side roads) were identified for each sub-option.
• The commonality of the side road re-alignments and new local links between each of the sub-options was investigated.
• Maps were prepared for each sub-option showing 100, 200 and 300m distance bands. These distance bands were drawn to encompass each new road link and each re-alignment that was not common between the sub-options(See Figure 5.2 – 5.5).
• A map was prepared for the baseline scenario with 100, 200 and 300 distance bands from the common start and end points used for each of the sub-options.
• For each sub-option and the baseline scenario, residential property counts were undertaken for each distance band.
• Receptors which are especially sensitive to noise and vibration, e.g. schools, hospitals, homes for the blind or aged persons or outdoor areas judged to be commonly used and subject to a noise level below 50 dB(A) were identified for each sub-option and the baseline scenario. These receptors were also categorised according to the distance bands.
• Detailed noise maps were prepared for each sub-option (See Figures 5.10-5.13) and the baseline scenario to allow accurate noise predictions for the year of opening +15. Each noise map extended beyond the 300m distance bands to allow the affect of more distant road traffic sources to be accounted for. Each noise map was based on the detailed sub-option cut and fill design and ground contour data for the site and surrounding area down to 1m intervals. OS mapping of the site and surrounding area was used in conjunction with detailed property counts and a site walkover such that the affect of existing buildings could be accounted for.
• Ambient and future noise levels were predicted for all receptors within the identified distance bands
• For each receptor, the noise level change was identified and categorised as an increase of greater than 1dB, a decrease of greater than 1 dB, and a neutral change of less than 1 dB.
• The results of the assessment were tabulated as follows to facilitate comparison

1. the numbers of residential receptors within each individual distance band (0 to 100m, 100 to 200m and 200 to 300m) and the total number of receptors within 300m, for each sub-option and the baseline scenario.

2. the number of receptors particularly sensitive to noise within each distance band and within 300m

3. the number of receptors subject to an increase of greater than 1 dB, a decrease of greater than 1 dB and a neutral change of less than 1 dB

• Conclusions were drawn based upon the tabulated assessment data.

In addition to the above, an assessment in full accordance with DMRB Stage 2would require the following:

• Noise level changes to be depicted on noise maps for the selected sample receptors
• An estimate of the distances from the road at which noise changes will not be discernible.
• An assessment of likely vibration nuisance to be undertaken for unscreened buildings within 40m of each sub-option.
• On rare occasions where ground-borne vibration on existing routes is likely to be a problem, measure vibration levels at the foundation of a sample of buildings considered to be at high risk, to identify whether levels are likely to exceed the threshold of perception. Based on these measurements, an estimate of the number of buildings likely to be exposed to perceptible vibration levels is to be made.
• A statement on the significance of potential noise changes both to local people in general and to sensitive locations in particular should be provided, considering both noise increases and noise decreases. The statement should consider possible reductions and increases in noise levels along the existing road network
• Route options that could require extensive noise mitigation measures to be identified
• Statements on potential vibration impacts to be provided for each sub-option.

Comments on Adopted Methodology:

DMRB Stage 2 requires that 100, 200 and 300m distance bands are drawn from the ‘centre line’. The guidance does not provide advice on whether the bands should consider the centre of just the primary route section, or all affected local routes. To highlight differences in the sub-options, it was considered most robust to include all new routes and realigned routes that were not common between the sub-options.

The DMRB states that property numbers can be estimated. In the interests of accuracy, property numbers were based on detailed counts.

The DMRB does not require that especially sensitive receptors properties are categorised by distance. This was completed to add extra clarity.

The Stage 2 assessment requires that a sample of representative receptors is adopted, but for robustness, noise predictions were carried out at all receptors within the identified distance bands. These tabulated changes were considered appropriate for comparing directly the relative merits of the various sub-options.

Comments on DMRB Stage 2 assessment components not included in the adopted methodology

As noise level changes were calculated and tabulated for every individual receptor, the identification of noise level changes at sample receptors was considered not to provide any additional information to that already considered in the appraisal.

It is anticipated that the distances at which noise level changes from the sub-options would be discernible would depend upon the local topography and distance between the current and proposed route alignments. These factors would vary across the length of each sub-option and would relate directly to the numbers of properties subject to noise increases and decreases. Therefore, this part of the assessment was considered not to provide any additional information to that already considered in the appraisal.

The Stage 2 vibration assessment is based upon the predicted LA10 18 hour noise levels, which have been used to determine the preferred sub-option. In addition, each of the route options would result in fewer receptors within the 40m distance criteria for the assessment than the baseline scenario. Consequently, should airborne vibration be a problem at the present time, each of the sub-options is likely to result similar improvements. Therefore this assessment was considered not to be critical to the selection of the preferred sub-option.

Regardless of whether ground-borne vibration is an issue with the current alignment, all of the sub-options would result in fewer receptors in close proximity to the A90. Therefore this assessment was considered not to be critical in the identification of the preferred sub-option.

The Stage II assessment requires a statement be made on the significance of noise impacts on local people and sensitive locations in particular. To ensure a robust assessment, the preferred sub-option was selected based on the numbers of individual receptors subject to noise level increases, decreases and neutral changes.

The significance statement requires consideration be given to noise level changes on the existing network. In the case of this development, each sub-option had the same junction alignments at the start and finish points and a similar junction towards the centre. As such, it was anticipated that similar noise level changes would results on the local network for each sub-options.

Where the sub-options are significantly different from each other, the nature of the surrounding area is rural. As such, it was considered unlikely that any sub-option would require significantly different levels of noise mitigation.

• Map showing existing community facilities and their catchment areas, route options and key pedestrian routes
• Assess existing usage of community facilities and routes used by pedestrians and others; the changes to journey times associated with route options and whether safety and amenity is compromised
• Consider vulnerable groups
• Assess community severance
• Take account of cyclists routes

See Figure 2.6

See Appendix B

Foveran Primary School Route

See Appendix B. no formal routes identified.

• Assessment of view from the road
• Consider driver stress for each route option

• Map showing: route options, areas sensitive to impacts, surface watercourses, classifications, extent of floodplains, groundwater protection zones, designated fisheries, areas of high amenity value
• Spill risk
• Pollution risk
• Effects of each route option on water quality and most vulnerable areas
• Proposed mitigation explained and quantified

All are described in Section 2.6.10 and 5.12

All sub-options cross the same major water courses including those which drain to the Ythan Estuary. Spill risk and pollution risk appraisals have therefore not been carried out for Stage 2 as it was not considered that these would be a useful decision tool. Detailed assessments, including calculations will be carried out for the preferred route for the Environmental Statement

Further detailed mitigation will be included in the Environmental Statement. Commitments to best practice and design considered to be adequate at Stage 2.

• Describe the geological/geomorphological interests of the area and assess the impact of the route options. The assessment should take account of any mitigation measures agreed
• State the likely impact of the route options on soils and contaminated land

See Section 2.6.11 and 5.13

No contaminated land has been identified within the study area. See Section 2.6.11 and 5.13

• Relevant SPPs/NPPGs
• Schedule of relevant policies from structure plan and local plan(s)
• Assess the likely impact of options on policy objectives

See Section 2.6.4

See Section 2.6.12