Environmental Statement volume 4 - Chiltern Evergreen3

4 METHODOLOGIES FOR ASSESSING ENVIRONMENTAL IMPACTS4.1 INTRODUCTION4.1.1 As explained in Section 2, the Applications Rules require an ES to report on thoseenvironmental effects which are considered likely to be significant.4.1.2 A significant effect is considered for the purposes of this project as an effect which,either in isolation or combination with others, should in the opinion of the EIAteam, be taken into account in the decision making process. The EIA team arrive atsuch an opinion using their professional skill and judgement.4.1.3 This definition will provide a common framework within which to predict thesignificance of effects for all environmental topics. A set of criteria for each of theenvironmental topics is discussed in the following sections and will be used inorder to predict significant effects arising from the scheme.4.1.4 The prediction methods set out in the following sections are based on previousexperience of similar environmental studies and the professional judgement ofERM and other consultants. In addition, account has been taken of statutoryrequirements, Government advice and professional guidance on best practice.Account will also be taken of webTAG (1) and emerging guidance in this area, asappropriate.4.1.5 For each environmental topic the environmental effects of the scheme will bepredicted by comparing baseline environmental conditions (ie the situation withoutthe proposed scheme) with the conditions which would prevail were the scheme tobe constructed and operated, taking account of the spatial and temporal scopes asdefined in Section 2.5. The ES will report the effects of the project withoutmitigation and once mitigation has been implemented. The mitigated effects arewhat are known as “residual effects” of the project.4.1.6 Reference will be made inter alia to the following policy and guidance inundertaking this assessment:European Transport Policy• White Paper on European Transport PolicyNational Planning Policy and Guidance• Planning Policy Guidance Note 13: Transport (PPG13), Department of theEnvironment, Transport and the Regions (DETR), 2001;• Transport White Papers;• Guidance on Transport Assessment, Department for Transport, 2007;• Manual for Streets, Department for Transport/Communities & LocalGovernment, 2007;(1) Department for Transport, Transport Analysis Guidance, www.webtag.org.ukENVIRONMENTAL RESOURCES MANAGEMENT39CHILTERN RAILWAYS LTD