Undertaking non-statutory EIA can have benefits, according to Nicky Lear, principal environmental consultant, Parsons Brinckerhoff.
Use of a non-statutory Environmental Impact Assessment (EIA) process has proved beneficial to Somerset County Council in delivering a fast response to improving access to the village of Mulchelney, which was cut off during extensive flooding to the Somerset levels in early 2014.
The non-statutory EIA process was used to assist the appraisal of proposed highway works at Muchelney which were running on a very tight delivery programme. The rapid mobilisation of site surveys, ongoing consultation and preparation of an environmental action plan to provide concise recommendations for the client and contractor, led to the project being delivered on time with all requirements met.
In early 2014 the Somerset Levels and Moors experienced widespread flooding, particularly within the catchments of the Rivers Parrett and Tone. Roads surrounding Muchelney were impassable from 10 January to 20 March to the extent that boats or an all-terrain vehicle were required to ferry people and goods in and out of the village. As part of the government response to the flooding, Somerset County Council proposed to raise Law Lane between the villages of Muchelney and Drayton by December 2014 in case of a repeat flood. The works required temporary and permanent land take due to the embankments necessary to support the raised road.
County Councilwhich considered potential options for maintaining access to the village during a repeat flood. These included raising the road between Muchelney and the village of Thorney and the construction of flood embankments. A new section of offline road was also considered between Muchelney and Drayton. Key environmental risks for each option were identified. It was concluded that online raising between Muchelney and Drayton was the preferred option. This option reduced the capital cost and construction period and minimised impacts on the environment compared to the construction of a new road offline.
Parsons Brinckerhoff was commissioned in June 2014 to undertake an environmental appraisal of the proposed works. The programme was challenging as the design was due to be completed in August, with construction commencing in September. Although a statutory EIA was not required, the EIA process was adapted using the non-statutory approach. In particular, this ensured that environmental issues were incorporated into the decision-making process and that consultation was undertaken.
Two design options were under consideration during the environmental appraisal; a symmetrical raising option with land take for embankments on both sides of the road, and an asymmetrical option with land take on one side of the road only. The environmental appraisal assumed maximum land take and vegetation loss to ensure all issues were covered in the event of design changes. Key issues were scoped with Somerset County Council and included disruption to local residents during construction, effects on ecology due to habitat loss, landscape and visual effects, water as the scheme involved the loss of minor drains and crossed two main rivers, and cultural heritage as Muchelney Abbey is a scheduled monument and lies adjacent to the route.
Site surveys were mobilised rapidly including a phase one habitat survey, bat survey, water vole survey, arboricultural survey, landscape and visual appraisal, archaeological desk-study and geophysical survey. A water framework Directive assessment and habitat regulations assessment screening were also undertaken. A key concern was the loss of vegetation lining the road which included rows of mature willow pollards. These were of importance to commuting bats and were key visual features in the landscape. The asymmetrical design adopted preserved one of the rows of trees in addition to one of the larger drainage ditches. All hedgerows lost were also reinstated.
The Parsons Brinckerhoff team worked closely with Somerset County Council throughout, providing early information on potential impacts prior to submission of the final report and providing information on potential consents and licences prior to construction.
Somerset County Council consulted with residents and landowners throughout the project and the environmental appraisal was also sent to statutory consultees. Following completion of the appraisal, an environmental action plan (EAP) was prepared summarising the issues, sensitive receptors and potential impacts identified in the appraisal, with mitigation measures and the responsibilities for delivery. This helped capture the main impacts, in addition to recommendations for mitigation which could be effectively passed to the contractor. Due to the timescale, archaeological studies were not complete prior to issue of the environmental appraisal so the both the report and EAP had to identify that further studies and consultation were required.
Following completion of the appraisal, the design was modified to raise the road to the south in the western half of the scheme and to the north in the eastern half in order to minimise environmental impacts.
The use of non-statutory EIA provided value to the project as potential environmental impacts were identified early, while the design was progressing. This led to a design which minimised environmental impacts as far as practicable. The appraisal has also provided valuable information and a tool for consultation in advance of works commencing on site, thereby reducing potential risk during the construction period.
