Experts from Parsons Brinckeroff describe how the assessment of cumulative effects, shaped the environmental impact (EIA) process for the proposed Newquay strategic route
The assessment of cumulative effects is required by the EIA Directive (85/337/EEC) and the UK EIA Regulations 2011. Cumulative effects are defined as resulting from multiple actions on receptors and resources, as a result of impacts from a single project or in combination with other developments.
The Newquay example
More than 750,000 people visit Newquay each year, the majority in the summer months, which causes congestion, particularly along the A392 to the south east of Newquay.
The Newquay strategic route will provide alternative access to the A3058 to the north east of Newquay from the A392, avoiding the town centre (see figure 1).
Figure 1: the proposed Newquay strategic route.
The proposed route crosses an undeveloped agricultural valley to the east of Newquay, which will eventually form an urban area; the Newquay growth area – a 200 hectare site first earmarked for development in the Restormel Local Plan (2001).
The Duchy of Cornwall is the majority landowner of the site. Development will include a mix of shops, offices and community facilities, including a new school, alongside integrated private and affordable housing, with a number of jobs created. Approximately 3,750 homes are expected to be built in the area (see figure 1).
A detailed planning application is being brought forward by Cornwall Council for the southern part of the road, between the A392 and the Par-Newquay branch railway line which will provide access to a proposed park and ride and Household Waste Recycling Centre.
Subsequent sections of the road will be brought forward as part of planning applications in the Newquay growth area. Several planning permissions, accompanied by environmental statements, have already been granted, but there is no specified timetable for other development in the area. It is anticipated that it will be largely complete by 2030.
Development to be assessed in the EIA
Two major factors contributed to the scope of the EIA that will accompany the planning application for Phase 1 of the strategic route:
- The detailed design and transport assessments are being undertaken for the whole route therefore it was decided the EIA should cover the entire route as well. This would avoid “project splitting” and cover any cumulative effects of the road element of subsequent planning applications, for example those relating to noise and air quality.
- Best practice advises that it is reasonable to consider cumulative effects of projects which already have planning permission. However, in this case, the development of the strategic eoute will form an integral part of the growth area and identification of cumulative effects is a key issue for this EIA.
The main interactions between the two developments and how these are being assessed is summarised below.
There is a large volume of detailed information on the growth area dating back a number of years , mainly relating to ecological and archaeological surveys. These have been used to inform the EIA for the strategic route.
Similarly, less information was available on air, noise and landscape considerations in the growth area, due to its strategic status. However, studies undertaken for the strategic route can be used to inform future development in the growth area.
Assessment of effects
The assessment of effects of the Newquay Growth Area has not been undertaken as a separate add-on at the end of the EIA, but integrated within the assessment for each topic in the EIA (see figure 2).
Figure 2: extract from the environmental statement
Significance of effect with mitigation
|Cumulative effect with NGA|
Grade II Listed buildings at Gusti Vean
Traffic movement may be visible and audible
|Embedded in the design||Slight||
Anciently Enclosed Land Historic Character Units (AEL 1, 2 and AEL6)
Alteration to setting
|Embedded in the design||Neutral||Slight|
The opening year for the completed route will be 2030 and by this date the Newquay growth area will be largely developed. Therefore, the assessment of effects is based on an urban environment rather than a rural one.
- The route will sit within a townscape, rather than open countryside;
- Ecology issues of severance and habitat loss need to be set within the wider mitigation strategy for the area; and
- Effects of air and noise will be felt by future adjacent communities, rather than existing receptors at some distance from the proposed road.
There is a large amount of strategic information relating to development within the growth area. The development scenario for the area is therefore based on a number of strategic documents, and the impact assessment makes the assumption that these strategies are in place.
It is therefore important to set out assumptions for the EIA, particularly in relation to future development. It is equally important to capture the limitations associated with the assumptions, as strategic information will not have the level of detail associated with cumulative projects at the planning application stage.
This article was written as a contribution to the EIA Quality Mark’s commitment to improving EIA practice.