PORR Construction UK: environmental mitigations for planned factory

Concrete factory proposed on sensitive brownfield site

PORR Construction UK Ltd wanted to build a new concrete products factory near the village of Wanstrow in Somerset. The company needed to gain planning permission to build on the former ‘Trinidad Works’ factory site on the A361, a brownfield site located adjacent to Torr Works quarry. PORR UK intended to use materials from the quarry to manufacture trackbed slabs for HS2 and other concrete components for major infrastructure projects.

However, getting planning permission on this site presented significant challenges. It was located in a flood risk area, bordered by woodland and a freight railway line. This meant drainage design was particularly challenging, especially since plans included provision for a potential railhead in future.

The site included wildlife habitats, including mixed deciduous woodland and hedgerows, which meant any development risked a loss of biodiversity. These habitats had the potential to harbour invertebrates, great crested newts, reptiles, birds, common dormice, otters and bats. There were also several Sites of Special Scientific Interest (SSSI) and Special Areas of Conservation (SAC) within 5km. In addition, access to the proposed factory was via an unclassified local road.

Solutions to address flooding and biodiversity concerns

SYSTRA was appointed to provide planning submission advice and associated environmental assessment work, and to devise environmental solutions to help the proposal gain planning permission.

To address flood risk concerns, our environmental specialists developed a surface water management strategy incorporating sustainable drainage systems (SuDS). These are designed to mimic natural habitats and manage rainwater close to where it falls. For the proposed factory site, they included permeable paving, sand and gravel areas, detention basins and areas of wetland – helping to tackle water pollution, enhance ecology, create attractive amenity areas and provide water attenuation.

To offset potential biodiversity losses, SYSTRA teams analysed surveys of three nearby areas with the potential to provide ecological mitigation. We calculated that these would provide sufficient habitats and opportunities for biodiversity improvement to ensure that no net loss of biodiversity was caused by the factory development. The mitigation areas offered scope to enhance biodiversity through a range of habitat-management measures, as well as providing suitable habitats for translocating slow worms present in the development site.

By assessing biodiversity on the site, we were also able to recommend alterations to the proposed design, to minimise the loss of important habitats. These alterations included relocating a vehicle storage area to minimise felling of broadleaf woodland, a reduced hard-standing area so that more habitat could be created, and reduced car parking spaces to avoid relocating hedgerows that were known to be commuting routes for greater horseshoe bats. Lighting designs were also adapted to minimise the impact on bats.

Exhaustive environmental assessments

SYSTRA provided a comprehensive range of environmental assessment services, encompassing noise, flood risk, landscape and visual, transport and travel, resources and waste, sustainability and resource efficiency, arboriculture, design and access, contaminated land, air quality, ecology, biodiversity net gain and heritage assessments.

Ecological and drainage adaptations achieve planning approval

The revised masterplan and adaptations to the planning submission led to Somerset Council granting planning permission for the new concrete products factory. The recommendations from SYSTRA meant that biodiversity net gain could be achieved for the proposal, as well as delivering an effective drainage solution for the site.

Without these adaptations, planning permission was unlikely to have been granted. PORR UK estimates that the new factory will create the equivalent of 300 full-time jobs in the local area.

“The SYSTRA Ecology team was very professional in how they went about the required ecological surveys and reports. They were very thorough. They went above and beyond what was required. They uploaded all the required drawings, data and reports to the Mendip County Council portal without any issues, which was a massive undertaking in itself.”

Richard Arnott, Contracts Manager, PORR Construction UK Ltd