A82 Dalnottar – Inverness Trunk Road A82 Ba Bridge Replacement Environmental Statement 2009 A82 Dalnottar – Inverness Trunk Road A82 Ba Bridge Replacement Environmental Statement 5 February 2009 Produced for Transport Scotland Buchanan House 7th Floor 58 Port Dundas Road Glasgow G4 0HF Prepared by Scotland TranServ Broxden House Broxden Business Park Lamberkine Drive Perth Perthshire PH1 1RA T 01738 455 300 F 01738 455 301 W www.scotlandtranserv.co.uk A82 Ba Bridg e Replacement – Environmental Statement REGISTER OF AMENDMENTS Name Signature Date Prepared By For and on behalf of Scotl and Tim Sweeney, Julie Bowen. 12/02/09 TranSer v Checked & Reviewed by For and on behalf of Scotl and Greg Fullarton 12/02/09 TranSer v Approved By For and on behalf of Scotl and Calum Galloway CGG 12/02/09 TranSer v Issue Status Final Purpose of Issue EIA required under Environmental Impact Assessment (EIA) (Scotland) Regulations 1999 Authorised for issue by Calum Galloway CGG 12/02/09 WP Ref: 06/NW/0202/007 Record of Issue Issue Status Author Date Check Date Authorised Date T Sweeney, 1 Draft 11-08 G Fullarton 11-08 C Galloway 11-08 J Bowen T Sweeney, 2 Final 02-09 G Fullarton 02-09 C Galloway 02-09 J Bowen Copyright All maps based upon Ordnance Survey material are produced on behalf of Transport Scotland under Licence No 100020540 2008 and used under the permission of Ordnance Survey on behalf of the Controller of Her Majesty’s Stationery Office © Crown copyright. Unauthorised reproduction infringes Crown copyright and may lead to prosecution or civil proceedings. Document Ref: A82 Ba Bridge Repl acement Issue Status: Final ii Copyright © Scotland TranServ Date: 05.02.09 A82 Ba Bridg e Replacement – Environmental Statement NON-TECHNICAL SUMMARY 1. Project Background 1.1. Introduction The Scottish Government (Transport Scotland) is proposing to replace Ba Bridge on Rannoch Moor (Figure 1.1) as it is under strength having been found to fail the minimum load carrying capacity for Trunk Roads. The bridge over the River Ba is located within Rannoch Moor Site of Special Scientific Interest (SSSI), Rannoch Moor Special Area of Conservation (SAC), Ben Nevis and Glen Coe National Scenic Area (NSA) and neighbours Rannoch Lochs Special Protection Area (SPA). The bridge carries the single carriageway A82 Trunk Road over the River Ba. Figure 1.1 The western side of the existing Ba Bridge. This scheme was formerly being developed by Jacobs Babtie on behalf of BEAR Scotland to undertake the due processes required by the ‘Environmental Impact Assessment (Scotland) Regulations1999’. The scheme is now being developed and completed on behalf of Transport Scotland by Scotland TranServ who took over the North West Contract to maintain and upgrade the Trunk Roads in 2006. The Environmental Statement (ES) identifies the existing (baseline) environmental conditions and presents a variety of measures to prevent or reduce the predicted impacts. These are known as mitigation measures. The Non-Technical Summary (NTS) is designed to provide an accessible summary of the ES and includes a brief description of the development proposals, the key potential environmental impacts and proposed mitigation measures. Document Ref: A82 Ba Bridge Repl acement Issue Status: Final iii Copyright © Scotland TranServ Date: 05.02.09 A82 Ba Bridg e Replacement – Environmental Statement 1.2. Existing Bridge Forming part of the A82, Ba Bridge is a three span bridge with parapets of coursed masonry, supported on masonry-faced concrete piers and abutments. It stands at a height of approximately 2.5 metres above the river level (Figure 1.1). An inspection concluded that the existing bridge structure was under strength and in need of repair to comply with British structural requirements for trunk roads. 2. Proposed Scheme Description 2.1. Scheme overview The scheme proposal is to replace the existing Bridge with a design that is both stronger and wider. The new bridge will be placed on the existing alignment but it will be of a different design. The new bridge will cross the watercourse in three spans using the two existing intermediate piers as central supports. These shall be lowered by approximately 1 m. New reinforced concrete abutments shall be constructed behind the existing masonry abutments to minimise construction activity adjacent to the watercourse. Throughout construction, traffic flow will be maintained on a temporary bridge, erected immediately to the west of the existing bridge. The temporary bridge will accommodate one lane of traffic that will be subject to appropriate traffic management to allow traffic flow in both directions. Upon completion the traffic will be moved onto the new structure, allowing the removal of the temporary bridge. As the new deck is to be wider than the existing one 2.5 m high by 5 m long reinforced concrete retaining walls are to be provided at the bridge corners. It may be necessary to extend the works slightly beyond the existing footprint in order to accommodate the carriageway cross-section. Provision for pedestrians shall be made on the temporary bridge and maintained throughout the construction phase. On completion of the scheme peat turves removed in the area of the temporary bridge will be replaced and the area shall be reinstated to its existing condition using local provenance seed mixes. 2.2. Construction 2.2.1. Construction programme The new bridge will be constructed by tendered contractors. It is anticipated that the construction works will be completed in stages as outlined in Table 2.1 Table 2.1 Key construction stages Stage No. Stage Description 1 Site compound establishment 2 Construction of substructure and foundations of temporary bridge 3 Construction and opening of temporary bridge 4 Removal of existing Ba Bridge 5 Construction of new bridge 6 Removal of temporary bridge Document Ref: A82 Ba Bridge Repl acement Issue Status: Final iv Copyright © Scotland TranServ Date: 05.02.09 A82 Ba Bridg e Replacement – Environmental Statement 7 Landscape works 8 Removal of site compound During construction, materials and the site compound will be located in a lay-by on the northbound carriageway, approximately 150 m north of the bridge and also at an informal lay-by directly opposite this on the southbound carriageway. The contractor will be permitted to work within normal construction hours from 0700 hours to 1900 hours during the summer months and may be less in winter, seven days a week for a period of 10-12 months. Night time working will be kept to a minimum in order to prevent disturbance to sensitive nocturnal species such a s otter and bat. Throughout the construction works, mitigation measures will be put in place to ensure that impacts on the local environment are minimised. 2.2.2. Traffic management and access Traffic management measures will be required during the construction period. A number of operations will require use of one-way traffic management and it is likely that this will be constant throughout the construction period. Pedestrian access will be provided throughout the duration of the programme although there may be short periods when access is restricted and pedestrians may need to be escorted through the site. 2.2.3. Options appraisal A report produced by Babtie in June 2002 ("Rannoch Moor/Glen Coe Assessment Review/Options Appraisal") considered the available options following a bridge failing to meet the BD21 Standards for Trunk Road bridges. These options were propping, strengthening, repair or closure. Propping is considered as a temporary measure in advance of strengthening, repair or replacement. The report compared and considered the advantages and disadvantages of various strengthening and replacement options. Subsequently, discussions with both BEAR and the Scottish Executive concluded that, on a value for money basis, the preferable solution was to replace the bridge. This is in recognition of the fact that, while there is an additional capital cost associated with the construction of a new structure, there are significant long-term benefits, including reduced maintenance costs. The option presented in this ES was considered to be the preferred option, taking into account technical, economic, environmental and stakeholder considerations. Document Ref: A82 Ba Bridge Repl acement Issue Status: Final v Copyright © Scotland TranServ Date: 05.02.09 A82 Ba Bridg e Replacement – Environmental Statement 3. Environmental Impact Assessment (EIA) 3.1. Consultation As part of the EIA process, a comprehensive consultation exercise was carried out with both statutory and non-statutory organisations. A total of 33 organisations were invited to comment and submit relevant information concerning the scheme and subsequent proposals. This exercise assisted in the identification of possible environmental impacts and the selection of appropriate study methods and mitigation measures, focussing on the most important, site specific environmental issues. 3.2. Scoping All of the receptors with potential to be impacted as a result of the scheme were considered during the scoping stage of assessment. As a result of scoping some of these were “scoped out” from further assessment and are therefore not considered in this environmental statement. This process is summarised in Error! Reference source not found.. Table 3.1 Summary of the issues scoped in and out Issue Scoping of Reason for scoping in/out Issue for Further Assessment Land use OUT No significant impacts to land use. Geology and soils IN Small area of disturbance to substrate and geological resources. Water quality and IN Bridge crosses a sensitive water course. hy drogeology Ecology and nature IN Surrounding area is of high natural heritage value. conservation Landscape IN New elements will be introduced to sensitive area. Visual issues IN New elements will be introduced to sensitive area. Cultural heritage OUT Unrecorded archaeological f eatures are unlikely to be f ound on site because the area would have been heav ily disturbed during the original construction of the A82 and Ba Bridge.