Reporting mitigation in environmental statements

David Hoare, of Hyder Consulting, reports on recent research into practitioners thoughts on how "embedded mitigation" and "mitigation" measures should be reported

The Town and Country Planning (Environmental Impact Assessment) Regulations 2011 require an environmental statement (ES) to contain: “A description of the measures envisaged to prevent, reduce and where possible offset any significant adverse effects on the environment.”

These measures, generally referred to as “mitigation”, often provoke much debate as to which should be classified as “embedded mitigation” – those that have been incorporated into the design of the development – and which should be classified as “mitigation” – those preventing, reducing and offsetting any remaining significant adverse effects.

A number of environmental impact assessment (EIA) professionals, comprising environmental consultants, EIA coordinators, lawyers, planners, landscape architects and ecologists, were recently surveyed by Hyder Consulting on the reporting of such measures.

When asked whether a distinction should be made in EIA/ES reporting between embedded mitigation and mitigation, more than 80% agreed that a distinction should be made.

When asked what the purpose behind making such a distinction is, the most common responses related to:

  • the ability to demonstrate the purpose of EIA early in the design process and its iterative nature;
  • encouraging the incorporation of mitigation measures early on in the design process;
  • demonstrating how the design of a project has evolved; and
  • demonstrating how the applicant has “designed out” significant effects.

Other responses suggested that making such a distinction allows the ES to differentiate between mitigation measures which are guaranteed, with limited or no flexibility in terms of deliverability, and those additional measures which are not integral to the project. These additional measures are, perhaps, less secure in terms of their implementation, less fundamental in terms of whether a project is acceptable and may also offer a degree of flexibility in how they are secured.

Some practitioners also suggested that creating a distinction between the two mitigation types allows the ES to focus on the effects of the project and those additional mitigation measures required to address potential significant effects, and therefore prevents unrealistic and unlikely effects from being reported.

In terms of where embedded mitigation measures should be reported in an ES, 50% of the respondees felt that they should only appear in one of the introductory chapters. Around 43% felt that embedded mitigation should be reported in one of the introductory chapters and within each relevant environmental assessment chapter. The remainder felt that embedded mitigation should only appear in the relevant environmental assessment chapter.

A list of commonly used mitigation measures was then provided, and practitioners were asked to label each measure as either embedded mitigation or mitigation.

The majority considered the following measures to be embedded mitigation:

  • incorporation of appropriate buffer distances from environmental receptors;
  • SuDS (sustainable urban drainage systems);
  • ensuring the layout of the project does not directly impact on sensitive receptors;
  • reducing the size and scale of the development; and
  • low-noise road surfacing.

Although opinion was more divided, most respondees also considered bunding, micrositing and directional drilling under watercourses to be embedded mitigation.

Practitioners’ opinions were divided 50/50 on whether the following measures where embedded mitigation or mitigation measures:

Meanwhile, most respondees agreed the following were mitigation measures:

  • adherence to a construction environmental management plan;
  • provision of compensatory land/features; and
  • double glazing.

Some respondees suggested that certain measures could be embedded mitigation, if they formed part of the project for which planning consent is being sought, or mitigation, if they were provided in response to an identified impact.

Practitioners also highlighted that reporting embedded mitigation with confidence is dependent on the status of the project at the time of submission. Finally, even if certain embedded mitigation measures are incorporated into the design of a project, it may be beneficial to demonstrate their effectiveness. For example, an ES could describe the effects with a noise barrier in place, but state that without the barrier noise levels are likely to be 10dB higher, which would represent a significant effect.

The results of this research suggest that while it is generally agreed a distinction should be made between embedded mitigation and mitigation measures, there is considerable conjecture as to which measures fall into which category and how such measures should be reported.

This article was written as a contribution to the EIA Quality Mark’s commitment to improving EIA practice.

David Hoare is a principal environmental consultant at Hyder Consulting.

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