The £12m anaerobic digestion (AD) plant at Bygrave Lodge Farm, near Baldock in Hertfordshire was developed as part of Biogen’s strategy to build a network of green energy plants across the UK. The AD plant provides a sustainable food waste treatment solution for homes and businesses in Hertfordshire and the surrounding areas.

The anaerobic digestion of waste is in itself a very sustainable process, but constructing such a plant in a greenbelt area presented many challenges, not least limiting the impact on the local environment.

Protecting and preserving the natural landscape was given priority consideration during the planning and construction phases of the project. In addition opportunities were sought to enrich the landscape and enhance the area wherever possible.

Planning regulations recommended the planting of several different species of trees to screen the AD plant, but the quantity was not specified. Long before the site was completed 14,000 trees were planted, forming a screen and also enhancing the future landscape. The tree species chosen and planted will be good food and habitat providers for birdlife once mature.

Other activities undertaken to improve the ecology and diversity:

• A screening bund was created using surplus materials from the construction site thus ensuring zero waste sent to landfill
• A balancing pond (flood basin) developed on site was adapted in order to provide pond habitat for amphibians and other wildlife
• Bunds were adapted to form beetle banks which will create a suitable habitat for invertebrates
• Perching posts for corn buntings, a species which has been in decline, have been installed to encourage their return to the area
• LED lighting was installed internally and externally providing low power consumption, low maintenance and less light pollution overall
• Rainwater harvesting was implemented to reduce potable water usage; all water on paved areas is captured and sent to the balancing pond also for re-use on site

The majority of the Bygrave site was initially considered to be of relatively low ecological value. As a result of the actions undertaken during planning and construction Biogen, in keeping with its values, succeeded in not only protecting the environment but also improving and enhancing it. The project also contributed to the ecological diversity of the local area.

The BREEAM Infrastructure assessment recognises and rewards best practice which is invaluable to a relatively new industry such as anaerobic digestion. Undertaking the assessment has helped Biogen develop a greater awareness of approaches to sustainability and provided standards and guidelines which can be implemented in future projects. The assessment has helped shape the decision-making process when considering the whole lifecycle of the Bygrave project and it is expected this will bring environmental benefits and cost savings to future developments.