The Natural Choice

Improving quarry sustainability by biodiversity offsetting

By Bob Edmonds and Simon Higson, SLR Consulting Ltd

Biodiversity offsetting is a way of compensating for adverse impacts associated with a development and, along with other forms of mitigation, has the aim of resulting in no overall net loss of biodiversity.

Many leading minerals operators have made corporate commitments to reduce impacts on biodiversity and are in a unique position to provide biodiversity gains through the restoration and enhancement of their minerals sites. A co-ordinated approach, using tools developed for calculating biodiversity offset values, provides a practical and useful method for reporting corporate biodiversity achievements and can potentially help new projects through the planning process.

Requirements for no net loss of biodiversity, whether driven by planning policy, legislation or voluntary action, may place an additional burden on developers. If integrated into long-term decision-making processes, offsetting may allow cost savings to be made and offers a potential source of revenue, while improving overall quarry sustainability.

Policy and regulatory background

DEFRA’s June 2011 Natural Environment White Paper: ‘The natural choice, securing the value of nature’, makes a commitment to ‘establish a voluntary approach to biodiversity offsetting...’.  This reflects recommendations from the earlier Lawton Review submitted to the Government in September 2010, which describes how biodiversity offsetting could be used to enhance ecological networks.

DEFRA has since published the ‘Guiding Principles of Biodiversity Offsetting’ and a technical paper: ‘Proposed metric for the biodiversity offsetting pilot in England’. It has also called for local authorities and their partners to pilot biodiversity offsetting over a two-year period, commencing in April 2012.

In July 2011, the Department of Communities and Local Government’s draft National Planning Policy Framework stated the widely reported ‘presumption in favour of sustainable development’, and also proposed, among other things, that ‘the planning system should aim to conserve and enhance the natural and local environment by…minimizing impacts on biodiversity and providing net gains in biodiversity, where possible’.

There are earlier legal precedents, such as the Environmental Damage (Prevention and Remediation) Regulations 2008 and the Conservation of Habitats & Species Regulations 2010 which allows the use of offsets on Natura 2000 (SPA, SAC or Ramsar) sites. These provide a basis for designing offsets that replace the natural resources or services lost, rather than linking offsets directly to the impact site.

Biodiversity at a typical quarry site – the current view

Quarrying is a temporary land use and although there will be the initial disturbance of habitats, there will also be provision for restoration, often incorporating or being solely dedicated to habitat creation and the enhancement of biodiversity.

Mineral operators may already have a corporate commitment to ‘positively contribute to biodiversity’ (HeidelbergCement Group, 2009) and some, including CEMEX UK, specifically recognize biodiversity offsetting as a tool that can help to compensate for negative impacts. Operators may also have produced site-based biodiversity action plans (BAPs) and/or commitments to enhancements, such as SLR’s BAPs for Tarmac UK’s northern and western regions.

In addition, many companies are already undertaking improved management within non-operational areas, such as carrying out native screen planting around site boundaries or excavating new ponds as part of surface- water management.

Some developments incorporate receptor areas that have been created or enhanced for species translocation from future working areas, eg licensed works for protected species such as great crested newts, reptiles or badgers. These areas often provide benefits for multiple species that are not always captured when assessing the long-term effects of a development.

Phased working and restoration may allow efficient management of soil and overburden resources and, via direct placement, permit the progressive creation of replacement habitats.

Ultimately, the final restoration can often provide better wildlife habitat than the original site.

It is well recorded that previously worked and restored quarries offer high potential for biodiversity enhancement, often achieving nationally important ecological designations, such as Site of Special Scientific Interest (SSSI). For example, Attenborough Nature Reserve and Little Paxton Pits both consist of restored gravel pits with open water, scrub and reed beds of national importance for bird life.

What is biodiversity offsetting and why is it different?

Biodiversity offsetting uses more formal methods to measure the losses associated with a development and seeks potential gains from actions identified to compensate for these losses.

The Business and Biodiversity Offsets Programme (BBOP, 2009), which includes Anglo American and Rio Tinto on its Advisory Committee, defines biodiversity offsetting as ‘…measurable conservation outcomes resulting from actions designed to compensate for significant residual adverse biodiversity impacts arising from project development after appropriate prevention and mitigation measures have been taken...’.

BBOP sets out the following guiding principles to ensure that offsetting is effective:

• design to achieve no net loss
• result in additional conservation outcomes
• follow the mitigation hierarchy (and seek to avoid or reduce impacts first)
• recognize that there are limits to what can be offset (eg some biodiversity, such as ancient woodland, is recognized through UK planning policy as irreplaceable)
• relate offsets to the landscape context
• allow stakeholder participation
• ensure long-term outcomes
• ensure transparency of process
• base the methodology on science and traditional knowledge.

Offsets differ from mitigation, compensation or enhancement as they are expressly designed to provide measurable outcomes that achieve no net loss as a result of an impact and can be delivered in three ways:

• On- or off-site habitat-based approach, where the area affected is offset by the creation or restoration of an equivalent area, typically on a case-by-case basis
• Habitat-banking, where the impact is converted to an exchangeable currency and used to ‘buy’ credits for other schemes that offset the biodiversity offsets
• In lieu fees, where a fee is paid directly to a banking scheme to be used for offsetting.

Measuring offsetting

DEFRA’s technical paper referred to earlier provides a tool for the measurement of biodiversity losses and gains – and/or compensation.

This is based primarily on the identification of the condition (from poor, moderate or good through to optimum) and distinctiveness (low, medium or high) of the habitat to determine biodiversity units per hectare (fig.1).

In this way an existing greenfield site can be assessed to define the overall value of biodiversity units before quarrying begins. A reassessment can then be made to describe remaining units based on defined extraction areas and an estimate of potential losses can be calculated.

Once biodiversity losses have been quantified, compensatory actions can be identified and measured. This could include undertaking perimeter screen planting or a revised management regime for grassland strips along quarry access roads and within standoffs.

The area, condition and distinctiveness of the overall quarry site (including compensatory actions) can then be reassessed to review whether net losses remain. How much compensation is required will depend upon the site-specific balance sheets and assessment of losses or impacts.

The opportunities for on-site compensation are likely to be influenced by the available space around the quarry perimeters or landholding, the condition and distinctiveness of local habitats and whether improvements to these habitats are possible. Often, areas of land outside an extraction area, but within the planning application boundary or landholding, will be limited in size.

This on-site approach can also result in compensation actions being targeted at inappropriate habitats, species or geographic areas, which can limit its effectiveness in delivering biodiversity objectives.

However, it is anticipated that in the longer term, depending upon the nature of the restoration scheme, all effects could potentially be compensated for, or improved on. This could result in an overall net gain of biodiversity units when the entire lifecycle of the quarry is taken into account (fig.2.).

Unfortunately, the time delay between the initial site disturbance and final/progressive restoration may be unacceptable, and this may create the need for off-site compensation, or offsetting.

Off-site compensation could be carried out as the improvement or restoration of another quarry site within the operator’s control or, in the absence of sufficient land, may need to be purchased as credits from another conservation project.

Conversely, where a quarry scheme delivers a high-quality ecological restoration project and results in overall net gains, these credits could potentially be used to offset future projects or be made available to other developers on the open market.

Case study: Bardon Hill Quarry extension

The planning application to extend Aggregate Industries’ Bardon Hill Quarry, which has an adjacent SSSI and large estate, included biodiversity offsets designed by SLR. The programme included a long-term biodiversity-management commitment to Bardon Estate, biodiversity-led restoration of on-site overburden tips and beneficial management of the nearby Ratchett Hill, a degraded lowland heathland site within the operator’s ownership. Approval was granted for the extension in May 2011.

Opportunities to manage costs

The requirement for no net loss of biodiversity may place an additional burden on developers in terms of evaluating, designing and implementing mitigation and compensation schemes.

Offsetting will become more important in the design of a development application and may offer improved clarity for planning decision-makers on the sustainability credentials of a particular scheme.

Operators may consider preparing for this by completing ecological audits of their landholding so that the existing biodiversity resource is recorded. In particular, identification of those areas that have the potential for enhancement and what value (eg in biodiversity units) might be derived and potentially used as an offset in future planning applications (either on site or off site).

Monitoring biodiversity improvements in more detail will allow areas brought into enhanced management to be included in corporate sustainability reporting in a measurable way.  Monitoring of actions and results will also allow a database of biodiversity credits to be maintained and evidence to be collected to back up specific restoration or habitat-creation activities.

Providing an outline of offset proposals at an early stage of the consultation process with the minerals planning authority should allow all measures offered to count, including those that may be undertaken in advance of specific applications.

Offsetting may put to use the potentially long-term aftercare liabilities associated with nature conservation schemes, where statutory five-year obligations are extended via Section 106 agreements. Continuous management over extended periods should gain additional biodiversity credits as the condition of the restored habitat improves, and these should be analysed and recorded.

The operator may also wish to evaluate whether it is more cost-effective to buy in credits, rather than use resources to pay for improvements to their own land. This may also include an evaluation of whether it is preferable to sell off any net gains from a project or use them as future offsets for their own operations.

Conclusion

The minerals industry is in a unique position to minimize the potential costs arising from the Government’s new sustainability agenda by managing its own landholdings in a way that maximizes biodiversity. An offsetting approach provides a mechanism to measure these benefits; could assist in making new development proposals more sustainable; and may offer a future source of revenue.

Offsets also have the potential to deliver additional ecosystem services, such as enhanced local amenities, flood storage or buffering to high conservation value sites. Importantly, biodiversity offsets should provide substantial benefits for the long-term maintenance and enhancement of biodiversity.

For further information visit: www.slrconsulting.com

This article was presented at the Institute of Quarrying’s 2011 Annual Conference Symposium.