The mitigation of potential adverse environmental impacts and effects is fundamental to successful environmental assessment and the delivery of EWR Co’s objectives. The Mitigation Hierarchy represents the sequence that is being followed, in order of priority, in the design and later construction of the project to eliminate and lessen potentially adverse environmental effects.
Opportunities to avoid potential impacts arise in the early stages of a project, when alternative proposals are developed, compared and evaluated. More detail on how EWR Co has considered the environmental impacts of the project at each stage of development is described in Appendix A of this report.
Through subsequent stages of the project lifecycle – from concept design, detailed design and through to implementation – opportunities to avoid and minimise adverse effects become fewer, and the emphasis shifts to rectifying and compensating.
Where the potential for a likely significant environmental effect has been identified during the course of the assessment, a mitigation measure is proposed where possible that would lessen the effect and ideally render it non-significant. If the measure is deemed feasible, practicable and effective, it would most likely be adopted within the design and at this point it is referred to as embedded mitigation.
The proposals described in the Environmental Statement (ES) for the project will assume embedded mitigation as an integral part of the project, and its impacts will be assessed on this basis. To ensure that these measures are retained through subsequent stages of design and implementation, they will be set out explicitly within the ES, which will be submitted as part of the DCO application. The implementation of those measures would then be secured through provisions included in the DCO as appropriate.
The design that is the subject of this consultation includes many features that have been adopted to mitigate potential environmental impacts; for example, south-west of Haslingfield the use of the tunnel beneath Chapel Hill would avoid or limit potential impacts on landscape, heritage and ecology. As another example, in the countryside west of Cambridge, proposals for block planting and hedgerow connectivity seek to integrate the linear project elements into the landscape. These early mitigation principles are described in the Technical Report and are summarised in the website pages that cover each of the eight route sections.
