Abstract
Environmental Impact Assessments (EIAs) in the UK must include a Cumulative Effects Assessment (CEA), however due to a lack of standardisation or guidance this process varies considerably between assessments (especially by country and by project). This raises the question of the utility and efficiency of the current CEA process. The following are some of the key areas in which CEAs can vary:
- Zone of Influence (screening range)
- Timeframe considered
- Assessment methodology
- Screening rules
- Data availability
- Assumptions made
- Magnitude definitions and significance scoring.
We recommend that UK wide SNCB guidance is developed so that CEAs can be standardised, leading to enhanced realism, representative and comparable CEAs – therefore streamlining a key element of the consenting process. The following are examples of what could be covered in such guidance:
- Standardisation of the screening range (Zone of Influence, or ZOI), preferably at a scale that is biologically meaningful to the receptor. For example, the management unit population.
- Standardisation of the timeframe included in the assessment. For example, for the assessment of construction noise, screen in all projects constructing at the same time as the Development in question ±2 years.
- Guidance on the information sources to be used in the data gathering stage. For example: obtain information from Environmental Impact Assessment Reports (EIARs) if available.
- Guidance on whether to quantitatively include projects without an EIAR available. If projects are to be included, then further guidance should be provided to standardise the assumptions behind deriving number of impacted animals. For example, the use of Effective Deterrence Ranges (EDRs) and specific density surfaces.
- Standardised approach to the quantitative assessment itself. For example, population modelling to quantify the potential cumulative impact to a receptor at a population level.
- Standardised definitions of magnitude in the significance scoring.
- Guidance and advice on how to make CEAs more realistic rather than assume compounding worst-case scenarios. For example, set realistic limits to the number of piling days available per year, realistic limits to the number of piling vessels able to operate in the area at the same time, etc.
It is recommended that the SNCBs and regulators in the UK hold a workshop to discuss these recommendations with a view of developing UK wide guidance.
An alternative solution could be that future CEAs are led by regulators/government agencies on a strategic/plan level, as is done in the US and the Netherlands. Given the demand and targets for renewable energy, we strongly advise that the current process is critically reviewed and amended to ensure a more streamlined consenting process going forwards.