The Nuclear Decommissioning Authority

As an old Dounreay waste dump is returned to nature, there is hope that sea birds will find its newly landscaped mound an attractive nesting spot.

The gravel covering on Landfill 42, which contains inert waste, was selected after Scottish Natural Heritage (SNH) suggested the surface would appeal to ground-nesting species such as gulls, oystercatchers and terns.

The site had lain unused by Dounreay Site Restoration Ltd (DSRL) since 2005, but was only recently identified as an ideal location for wildlife. Now it has been re-profiled and capped in a £1.6 million project to seal the contents away from people and the environment.

DSRL and its contractors pulled 50,000 tonnes of material back 10 metres from the cliff edge and created a symmetrical mound.

The project team sank bore holes into the mound to allow monitoring, while a network of drains was constructed to divert water around the area to the coast.

The waste mound itself was covered with a heavy-duty plastic membrane, welded to form an impervious cap overthe landfill.

A thick orange geo-composite fibrous layer was laid over the top to protect the membrane, before being covered with the 20cm deep layer of reddish-pink gravel.

The DSRL project team consulted SNH when designing the landfill's final surface. The finish is not unlike the shingle beaches of England's south coast and should provide an irresistible nesting area for birds.

Project sponsor Phil Cartwright explained that as the site was being demolished and returned to nature, great efforts were being made to encourage endangered and protected species to return and colonise the areas.

"We have set aside a wild flower meadow that is attracting an endangered speciesof bumblebee, and last year we moved a colony of the rare Scottish Primrose to protect it from excavation work," he added.

"Thanks to good teamwork between DSRL and its contractors, the project has been completed four months early, just before the start of the nesting season."