Study aims and approach
The aims of this project are:
- To improve understanding of the scope and scale of increased traffic volumes in communities around sites, over the four stages of unconventional oil and gas development (exploration, appraisal, production and decommissioning & restoration).
- To improve understanding of the range of potential impacts (and duration of impacts) of these traffic volumes, and characterise potential impacts in sites of different types.
- To identify robust regulatory and other options that could mitigate impacts on communities and the environment.
In order to evaluate the potential impacts of traffic associated with unconventional oil and gas development in Scotland, we have firstly set out the policy and regulatory controls on road traffic associated with new development in general, and UOG in particular. We have then investigated the likely scale of material quantities and traffic changes associated with UOG activities in Scotland. We have considered evidence for the community impacts associated with road transportation, and assessed the means for avoiding or mitigating community impacts resulting from transportation due to UOG development. We have considered a number of case studies to inform the study conclusions.
Based on this analysis, we have drawn conclusions regarding the potential impacts and made recommendations for measures which would be needed to mitigate impacts.
Regulatory and planning framework
The existing regulatory and planning framework would be applicable to UOG developments. Each relevant UOG development can be required to undergo the Environmental Impact Assessment ( EIA) process, in view of legal obligations for larger scale development, local authority powers to require an EIA for smaller scale developments, and industry undertakings to carry out EIAs. Mitigation measures can be implemented through planning conditions or in accordance with Section 75 of the Planning etc. (Scotland) Act 2006.
Traffic impacts of unconventional oil and gas development
The development of Scotland's unconventional oil and gas resources would result in associated road traffic movements. Road transportation would be needed for movement of plant, equipment, materials and waste. Each shale gas well pad could require between 13,000 and 93,000 vehicle movements, spread over about a 20 year period. A coal bed methane well pad is estimated to require about 93,000 vehicle movements over about 12 years. Traffic movements would be at their highest during well pad construction and hydraulic fracturing. Traffic movements could be sustained at around 190 per week for a period of approximately 2 years during development of a pad with 15 wells. For context, typical traffic flows associated with other traffic-generating development include:
- Food superstore: Approximately 60,000 two-way vehicle trips per week
- Warehouse / distribution centre Approximately 5,000 two-way HGV movements per week
- Windfarm at construction stage Approximately 800-1,000 two-way movements per week
The additional traffic movements associated with onshore oil and gas resources are unlikely to be significant or detectable at a regional or national scale, in view of the much greater numbers of traffic movements resulting from other activities. The contribution of UOG development to traffic and associated impacts such as carbon emissions at a regional or national scale would be slight and comparable to many other industry sectors and activities.
Consequently, the key focus for consideration of potential community impacts of UOG development is the assessment and management of potential impacts on communities local to development sites.
Potential community impacts from transportation
Road traffic impacts would arise principally from increases in heavy goods vehicle movements on potentially unsuitable roads. These movements would take place over a relatively limited period for an individual well, but may occur over a much longer period for development of a multi-well pad, and in particular in situations where a shale gas field is being developed.
Sites with good highway links, and sites located in industrial areas are likely to have relatively low potential community impacts due to traffic. Sites in rural or urban/suburban settings would have a greater potential for community and environmental impacts. In all cases, the potential impacts should be carefully considered through the planning process. Sites with the opportunity to reduce water transport ( e.g. through mains water connection; re-use of waste water on site; piped water supply and/or removal) would be more favourable.
The main potential community impacts of traffic associated with UOG development are as follows:
- Accelerated road surface degradation. This impact could be mitigated through cost recovery through taxes or fees; through policy measures; and/or by altering infrastructure to make it more resilient. Specific actions may include road condition surveys, specified remedial works, and/or making a payment under a Section 96 agreement to recover the cost of road repairs.
- Risk of increased accidents. Increased UOG traffic in areas of intensive UOG development in the USA has resulted in increased incidence of accidents in affected communities.
- Risk of accidental release of hazardous material during transportation. Truck accidents could potentially lead to chemical or wastewater spills. There are systems in place in the UK to manage chemical spillage in the event of a traffic accident. These controls would reduce, but not fully eliminate, such risks.
- Air pollution impacts. Increases in vehicle movements would result in an increase in emissions of air pollutants which would need to be considered in the planning process. In most cases, effects on local air quality are expected to be minor, but the potential for localised impacts would depend on the nature, scale and location of a proposed development.
- Noise. Noise associated with traffic movements to and from UOG facilities could potentially affect nearby residents. This would need to be taken into account in the planning process.
- Nature conservation. UOG activities can potentially affect biodiversity via a number of routes, although the likely setting of UOG development in Scotland means that impacts on remote habitats are unlikely. Nature conservation impacts would need to be taken into account in the assessment of any UOG development.
Managing the road traffic impacts of new development is a well-established discipline with project developers and regulatory authorities. To ensure that appropriate mitigation measures are identified, implemented, enforced and managed, the following is recommended.
1. National, regional and local plans should set policies to guide the development of UOG resources, in the event that the moratorium is lifted.
2. All planning applications for UOG development should be made subject to an Environmental Impact Assessment. This would include an assessment of impacts relating to traffic movements and the identification of appropriate mitigation measures, such as avoidance of transportation of water to and from the site by road, where possible.
3. A Traffic Management Plan should be required to support planning applications for UOG sites.
4. Discussions should take place between the developer and the local authority with regard to the provision of a Roads Condition Survey and provision of an appropriate financial bond to cover any required road repairs, potentially supported by planning condition.
5. At appropriate sites, an Enforcement Officer should be appointed to ensure that mitigation measures are implemented and enforced throughout the life of the project.
6. It is understood that the oil and gas industry is developing a set of key principles in relation to transportation. These should be evaluated, and, if appropriate, taken into account in the planning process.
Residual community impacts from transportation
Assuming that appropriate strategic policies are put in place, and appropriate mitigation is carried out, local communities would nevertheless experience an increase in traffic numbers, potentially for an extended period of a number of years. Any increase in vehicle movements could result in an increase in noise, emissions to air, road damage, or traffic accident risks, which may be identified as negligible, or may require mitigation. Provided the planning and EIA system is properly implemented, any significant impacts would be avoided through the use of appropriate mitigation measures.