Cummulative Effects

Introduction

This chapter describes the assessment of cumulative effects for the A75 Springholm and Crocketford Improvements (hereafter referred to as “the proposed scheme”).

Cumulative Assessment Methodology

Annex IV of the Environmental Impact Assessment (EIA) Directive (2014/52/EU) (amending Directive 2011/92/EU) (hereafter referred to as the “EIA Directive”) requires the consideration of the cumulative effects within an Environmental Impact Assessment Report. This requirement is reflected within Schedule 1A of the Roads (Scotland) Act 1984 (Environmental Impact Assessment) Regulations 2017.

While the term 'cumulative' is not defined within the EIA Directive, the European Commission (EC) guidelines define 'cumulative impacts' as follows: 'Impacts that result from incremental changes caused by other past, present or reasonably foreseeable actions together with the proposed scheme'.

Design Manual for Roads and Bridges (DMRB) LA 104 - Environmental assessment and monitoring (revision 1) (hereafter referred to as “DMRB LA 104”) states that ‘EIAs must include cumulative effects in accordance with the requirements of the EIA Directive 2014/52/EU’ and provides a glossary of technical terms, which expands on the above definition, noting that a cumulative effect may arise as the result of:

a) the combined impact of a number of different environmental factors - specific impacts from a single project on a single receptor/resource (referred to as Type 1 cumulative effects); and/or

b) the combined impact of a number of different projects within the vicinity (in combination with the environmental impact assessment project) on a single receptor/resource (referred to as Type 2 cumulative effects).

In this chapter, cumulative effects are separated into two main sources as follows:

Intra-project effects, during this Environmental Appraisal Report (EAR) will be referred to as “combined effects” which are the effects that occur when different environmental aspects from one project, impact a single environmental receptor. An example of this would be local residents being impacted by construction noise, visual changes and dust during the construction phase of the proposed scheme.
Inter-project effects, during this EAR will be referred to as “cumulative effects”. This effect occurs when impacts from different projects in an area have influence on a receptor. An example of this could be two sets of temporary traffic lights from different projects in one area that cause major congestion for residents.

Combined Effects Methodology

Combined effects are recognised when a receptor is affected by a proposed project that will have multiple environmental impacts.

For each improvement strategy the assessment identifies, with a reasonable assumption, the potential key receptors with a likelihood for significant effects which have been identified in the previous environmental factor chapters. Consideration is then given to how those effects may add up during the construction and operational phases.

Some of the potential combined effects may have already been identified in previous environmental factor chapters. For example, the potential for effects from dust and noise on sites of ecological importance or human receptors have been detailed in the Biodiversity Chapter and Noise and Vibration Chapter of this EAR respectively. Such assessments have not been duplicated in this chapter, but where appropriate, references have been made to the relevant environmental factor chapter without repeating the assessments.

There is potential, in some instances, to highlight the probability for the effects of different outputs acting upon the same receptor, without the ability to provide details of the interactions between those effects. At the current stage of assessment, the potential for these effects is noted, with the intention is that they would be reviewed at a later stage of assessment.

Cumulative Effects Methodology

The guidance for assessing cumulative effects is outlined in Sections 3.19 to 3.22 of the DMRB LA 104. The guidance states that a Zone of Influence (ZoI) should be established for the proposed scheme along with other projects. The ZoI is a defined geographic area that will be used to encompass environmental receptors that could be impacted by the proposed scheme.

For this assessment, the General ZoI was first identified for the proposed scheme and set at 2km from the improvement strategies. This was chosen for the identification of other proposed projects which have the potential to contribute to cumulative effects. The General ZoI is mapped on Figure 15-1. Each environmental factor has an independent ZoI relative to the required study area for each of their assessments, these are identified in Table 15-1 below.

Table 15-1: ZoI for Each Environmental Factor
Environmental Factor	Maximum ZoI from the Improvement Strategies
Air quality	2km buffer from the improvement strategies
Cultural heritage	1km and 500m buffer from the improvement strategies
Landscape and visual	2km buffer from the improvement strategies
Biodiversity	2km buffer from the improvement strategies
Geology and soils	100m buffer from the improvement strategies
Noise and vibration	600m buffer from the improvement strategies
Population and human health	500m buffer from the improvement strategies
Road drainage and the water environment	500m buffer from the improvement strategies
Material assets and waste	Within the improvement strategies

The next step was to identify a list of developments that have the potential to impact shared receptors with the proposed scheme. DMRB LA 104 lays out the types of developments that the assessment of cumulative effects should report on:

Roads projects which have been confirmed for delivery over a similar timeframe (2025 – 2035).
Other development projects with valid planning permissions or consent orders, and for which EIA is a requirement.
Proposals in adopted development plans with a clear identified programme for delivery.

Nationally Significant Infrastructure Projects: Advice on Cumulative Effects Assessment details a broader list of developments that should be included within a cumulative effect assessment in comparison to DMRB LA 104. For example, developments that have been submitted for planning but have not yet been determined. The guidance does not relate to the options identification stage as it is not considered proportionate to include such developments during DMRB Stage 1. These aspects would be considered in the cumulative effects assessments during later DMRB stages.

To identify a list of other relevant proposed developments, data has been gathered for the Committed Development Log (CDL). The following types of proposed developments have been searched for, and identified within the General ZoI of the proposed scheme:

Major developments (as defined in the Town and Country Planning (Hierarchy of Development) (Scotland) Regulations 2009 (the Hierarchy Regulations)) which have been granted planning permission and there is potential for significant environmental effects.

Other major developments, including the following:

National developments that have been designated by Scottish ministers under the National Planning Framework 4 .
Developments under the Transport and Works (Scotland) Act 2007.
Allocations in the relevant adopted and emerging development plans.

The following information was included in the search for all relevant developments and allocations identified within the General ZoI of the proposed scheme:

For developments:

Application reference
Description of the development
Application type
Applicant
Site location
Development type
Application status

For allocations:

Allocation policy
Local planning authority
Local planning document
Site name
Allocation type
Size
Local plan status (adopted/emerging)

All the identified developments and allocations are considered to have the potential to contribute to the cumulative effects with at least one of the improvement strategies. The developments and allocations are discussed in the Assessment of Cumulative Effects section of this chapter , with a list of allocations within the ZoI in Table 15-2.

At DMRB Stage 1, it would be deemed disproportionate to evaluate the significance of the cumulative effects for each improvement strategy. As a general assumption, an improvement strategy with more developments or allocations within the study area has a greater potential for cumulative effects compared to an improvement strategy with fewer developments or allocations.

Assumptions

Projects were provisionally screened against indicative thresholds identified under Schedule 3 of the Town and Country Planning (EIA) (Scotland) Regulations 2017. Projects which exceed those thresholds have the potential to cause significant environmental effects, and such projects were therefore included in the short list. Although the thresholds are indicative only, and the sensitivity of the receiving environment would also be considered in any formal EIA screening determination, the use of the thresholds for shortlisting is considered proportionate at this stage of the assessment to inform options identification.

The Committed Development List (CDL) was based on data available in March 2025, and therefore any developments that are brought into the public domain after this were not included at this current stage of assessment. Development and allocations in the designated ZoI will continue to be monitored in the later stages of assessment.

The CDL contains information regarding major applications from March 2020 to March 2025, as this time span is deemed suitable for this current stage.

Applications that have been refused planning permission were excluded from short list as it would be unlikely for these projects to be constructed and to have potential for cumulative effects. Similarly, other applications at various stages of the appeals process have been excluded from the list. Changes to the application status of other projects will continue to be gathered to inform updates to this work in later stages of the proposed scheme.

The climate change assessment (included in the Climate Change Chapter of this EAR) considers the proposed scheme’s potential to affect the national climate (as a result of changes in Greenhouse Gas (GHG) emissions) and the effect of changes in climate on the proposed scheme itself, and therefore does not require further assessment in the cumulative effects assessment. It is assumed that a temporal link between identified developments and this proposed scheme is likely, but no online searches have been conducted for construction dates for these developments. The information isn’t likely to be readily available online or could be unreliable in nature.

At DMRB Stage 1, the compilation of the list of other projects for cumulative effects assessment has been carried out by the assessor alone, however in later DMRB Stages of the proposed scheme (to support statutory EIA, if required), it is expected that relevant stakeholders should be consulted to create that list.

Limitations

At this early stage of assessment there is no way to carry out a meaningful assessment of the likely significance of potential cumulative effects. The current improvement strategy design information is limited, as is expected for DMRB Stage 1. Individual environmental factor assessments are based on preliminary stages of qualitative assessment. The cumulative assessment will be undertaken progressively as the proposed scheme moves into DMRB Stage 2 when a developed understanding of likely significant and potential effects for both the construction and operational phase is known.

Assessment of Combined Effects

The assessments contained in the environmental factor chapters of this EAR describe specific impacts on the individual receptors in terms of a range of environmental factors. In many of instances the range of potential impacts on receptors are addressed within each environmental factor specific chapter. The following sub-sections describe the receptors that may be affected by potential combined effects. The receptors described are relevant to all improvement strategies.

Residents in Close Proximity to the Improvement Strategies

There are potential combined adverse effects on residents at properties in the vicinity of the proposed scheme during construction and operation due to:

Changes in views.
Potential risks to human health from soil contamination.
A worsening of human health as a result of increases in noise and vibration.
Disruption to or loss of access/severance.
A potential increase in flood risk.

Aspects that share this receptor include:

Air Quality
Landscape and Visual
Geology, Soils and Groundwater
Noise and Vibration
Population and Human Health
Road Drainage and the Water Environment

Users of Community Facilities, Public Open Space and Public Rights of Way

There would be combined adverse effects on users of community facilities, public open spaces and public rights of way in the vicinity of the proposed scheme during construction and operation due to:

Changes in views.
Potential risks to human health from soil contamination.
A worsening of human health as a result of increases in noise and vibration.
Disruption to or loss of access/severance.
A potential increase in flood risk.

Aspects that share this receptor include:

Air Quality
Landscape and Visual
Geology, Soils and Groundwater
Noise and Vibration
Population and Human Health
Road Drainage and the Water Environment

Agricultural Landholdings

There would be combined adverse effects on agricultural landholdings in the vicinity of the proposed scheme during construction and operation due to:

Loss of agricultural land and degradation of soil quality.
Disruption to or loss of access/severance.
A potential increase in flood risk.

Aspects that share this receptor include:

Geology, Soils and Groundwater
Population and Human Health
Road Drainage and the Water Environment

Peat Bogs

There would be a combined adverse effect on the identified areas of Peat in the vicinity of the Proposed scheme during the construction and operational phase due to:

Loss of valued peat land in the area
Increase in carbon emissions due to the removal of natural carbon sink.

Aspects that share this receptor include:

Geology, Soils and Groundwater
Population and Human Health
Climate
Material Assets and Waste

As the proposed scheme progresses into the next stage, further assessment will be required for the identified combined effects on the specific receptors.

Assessment of Cumulative Effects

During this DMRB Stage 1 appraisal, a high-level search has been conducted using the methodology above, during the search there were no developments identified within the ZoI that would classify as Major using the guidance from The Town and Country Planning (Environmental Impact Assessment) Regulations 2017. Updated searches will be carried out in DMRB Stage 2.

Using the Dumfries and Galloway Council Local Development Plan 2 (hereafter referred to as “LDP2”) to identify land allocations for proposed developments, 11 allocations were identified within 2km of the improvement strategies (10 situated within Castle Douglas and one in Springholm). All 11 allocations are within the boundaries of Improvement Strategies 1 and 6, while the other four improvement strategies have only one allocation within their boundaries. Table 15-2 lists the allocations with the potential for cumulative effects according to guidance.

Table 15-2: Planning Allocations within 2km of the Improvement Strategies
Allocation Policy Reference	Local Planning Authority	Allocation Site Name	Local Plan Document	Size	Adopted or Emerging	Allocation Type	Improvement Strategies Within 2km
CSD.H1	Dumfries and Galloway Council	North of Garden Hill Drive	Dumfries and Galloway Council Local Development Plan 2	15 units allocated up to 2029	Emerging	Housing	1 and 6
CSD.H2	Dumfries and Galloway Council	West of Garden Hill Road	Dumfries and Galloway Council Local Development Plan 2	30 units allocated up to 2029	Emerging	Housing	1 and 6
CSD.H3	Dumfries and Galloway Council	East of Ernespie Road	Dumfries and Galloway Council Local Development Plan 2	130 units allocated up to 2029	Emerging	Housing	1 and 6
CSD.H4	Dumfries and Galloway Council	Cotton Street	Dumfries and Galloway Council Local Development Plan 2	16 units allocated up to 2029	Emerging	Housing	1 and 6
CSD.H5	Dumfries and Galloway Council	West of Torrs Road	Dumfries and Galloway Council Local Development Plan 2	133 units allocated up to 2029	Emerging	Housing	1 and 6
CSD.H6	Dumfries and Galloway Council	South of Jenny’s Loaning	Dumfries and Galloway Council Local Development Plan 2	190 units allocated beyond 2029	Emerging	Housing	1 and 6
CSD.H10	Dumfries and Galloway Council	Land to south of Ernespie Lodge	Dumfries and Galloway Council Local Development Plan 2	25 units allocated up to 2029	Emerging	Housing	1 and 6
CSD.H11	Dumfries and Galloway Council	Land to south of Kilmichael, Abercromby Road	Dumfries and Galloway Council Local Development Plan 2	35 units allocated up to 2029	Emerging	Housing	1 and 6
CSD.H203	Dumfries and Galloway Council	Land at The Stables	Dumfries and Galloway Council Local Development Plan 2	180 units allocated up to 2029	Emerging	Housing	1 and 6
CSD.B&I1	Dumfries and Galloway Council	Land at Oakwell Road	Dumfries and Galloway Council Local Development Plan 2	1.48 hectares	Emerging	Business and Industry	1 and 6
SPR.H1	Dumfries and Galloway Council	Land off Ewart Place	Dumfries and Galloway Council Local Development Plan 2	40 units allocated up to 2029	Adopted	Housing	1, 2, 3, 4, 5 and 6

Summary of Effects

The cumulative effect assessment identified that the following receptors may be subject to combined effects:

Residents in close proximity to the improvement strategies.
Users of community facilities.
Public open spaces.
Public Rights of Way (PRoW).
Agricultural land holdings.
Peatland.

There have been no major developments identified during searches that would contribute to cumulative effects. Land allocated for development by Dumfries and Galloway Council though the LDP2 was recorded within 2 km of the improvement strategies. All 11 of the allocations are situated within 2km of Improvement Strategies 1 and 6. This means that Improvement Strategy 1 and 6 are likely to have the largest potential for cumulative effect on the surrounding area, given the number of allocations.

The list of developments and allocations will be reviewed at DMRB Stage 2.

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