Approach to Environmental Assessment

6.1.1                   This section of the Non-Technical Summary summarises the approach taken for the EIA process to date, to identify and evaluate the likely significant effects associated with the Project.  EIA is intended to be an iterative process, which extends from project inception through to the final design and considers a project’s impacts during its construction and operational stages.

Scope of the Assessment

6.2.1                   Scoping is the process of identifying the issues to consider within the EIA process (ie establishing the scope of the assessment). A request for an EIA Scoping Opinion was made to the Planning Inspectorate in September 2019. This was supported by a Scoping Report, which set out the proposed technical scope, assumptions and methodology for the EIA process and its supporting studies. The Scoping Report was consulted upon widely by the Planning Inspectorate and responses were received from numerous stakeholders including statutory and non-statutory consultees, parish councils and members of the public.

6.2.2                   Following consultation with the statutory bodies, the Planning Inspectorate (on behalf of the Secretary of State) provided a Scoping Opinion on 11 October 2019.

6.2.3                   The scope of the EIA process underway for the Project, and the scope of the PEIR, has been informed by legislative requirements; the nature, size and location of the Project; the Scoping Opinion and consultation responses received to date.

Assessment Years

6.2.4                   The approach to assessment has incorporated the use of identified assessment years to allow for preliminary evaluation of the likely effects during the phased construction process and during the operation of the Project. The following assessment years have been used to inform this PEIR:

• 2024 to 2029, representing the initial construction phase prior to opening of the altered northern runway;
• 2029: represents the opening year of the altered northern runway (and therefore the first point at which effects arising from its operation would occur);
• 2032: an interim assessment year;
• 2038: representing the year in which the development works proposed as part of the Project would be completed; and
• 2047: to meet a specific requirement of guidance in the Design Manual for Roads and Bridges to assess impacts 15 years after the last of the key highways works associated with the Project are due to be completed.
  5. For the purposes of this PEIR, assessment concentrates on the period 2029 to 2038, with modelling topics modelling 2029, 2032 and 2038 as the primary assessment years.  In addition, for some topics it is a requirement to assess the effects of the highways improvements 15 years after completion. Therefore, for these topics, an assessment is provided for 2047.  Although the throughput at the airport is predicted to grow slightly between 2038 and 2047, no greater effects for other topics are predicted in this assessment year (due to factors such as improvements in aircraft performance over time). 

Cumulative Effects

6.2.6                   Cumulative effects with other proposed developments have been assessed as part of the EIA process. This includes consideration of whether the Project, when considered together with other proposed developments, may result in any greater effects on a receptor than the effects of the Project alone.

Heathrow Third Runway

6.2.7                   There is still significant uncertainty surrounding when, or indeed if, a third runway will be developed at Heathrow. However, as a third runway at Heathrow remains Government policy, it is considered within the PEIR as a cumulative development (where appropriate), in line with other proposed developments, based on the information available at this time.  However, information regarding the timing of the Heathrow works coming forward is limited at this time. As GAL progresses its work and prepares its final documents, including the formal Environmental Statement in support of an application for development consent, the status and information available regarding Heathrow’s third runway will be considered and taking this into account, the assessment of cumulative effects will be kept under review. 

Significance of Effects

6.3.1                   Environmental Impact Assessment is a means of identifying and collating information to inform an assessment of the likely significant environmental effects of a development.  For each of the key environmental topics, the following have been described:

• methodology/approach to assessment;
• description of the existing environmental (baseline) conditions and potential future baseline conditions (in the absence of the Project);
• identification and assessment of the significance of likely effects arising from the Project;
• identification of any mitigation measures proposed to avoid, reduce and, if possible, remedy adverse effects; and
• assessment of any cumulative effects with other proposed developments planned in the area.
  2. In terms of significance, effects are described using the following scale:
• substantial;
• major;
• moderate;
• minor; and
• negligible.