(01286) 679426 ygc@gwynedd.llyw.cymru

A487 Caernarfon and Bontnewydd Bypass ECoW

Client: Welsh Government / TACP Architects Ltd
Contractor: Jones Bros/ Balfour Beatty
Value: £ 139 million
Completion:  Feb 2022

The Caernarfon and Bontnewydd bypass scheme is one of the largest recent infrastructure project in North Wales. The road will span a total of 9.8km from the Plas Menai roundabout, around Caernarfon, Bontnewydd, Dinas and Llanwnda to the Goat roundabout on the A499/A487. The bypass will deliver improved travel times, reduce congestion, improve air quality on local roads and improve safety of active travel in the area.

YGC were commissioned by TACP to undertake an Environmental Clerk of Works (ECoW) position during the construction of the new Caernarfon and Bontnewydd bypass. The role of the Environmental Clerk of Works is to provide advice about environmental issues during the construction process, to ensure that the scheme is compliant with legislation and good practice. Typical issues include protected species, pollution, surface water management, material management, air quality and noise.

Some key work involved;

  • Monitoring and co-ordinating the control of invasive non-native species (INNS)

  • Monitoring the maintenance of temporary bat fencing is maintained and adapted as scheme progresses

  • Co-ordinating ecological checks and supervision

  • Attenuation pond and water resource management

  • Surface water management and pollution prevention

  • Provision of biodiversity enhancements to structures

  • Further work involved YGC’s ecology team to complete surveys across the scheme including;

    Amphibian pond surveys

    YGC was commissioned by TACP to assist with pond surveys around the area to gather data on existing amphibian populations for monitoring post- construction. The surveys involved torch counts, bottle trapping and egg searches.

    Amphibian drainage survey

    TACP and NMWTRA commissioned YGC to conduct surveys of gullies and drainage along the new road to establish a baseline for the presence of amphibians in the drainage system, and any impact the system may have on amphibians once the road has opened. The surveys involved deploying approximately 40 nets into drainage gullies along the scheme, which were then checked weekly to identify and release trapped amphibians.

    Surveys are predicted to carry on once the road has opened in early 2022 to monitor post-construction impacts on amphibians.

    Bat surveys

    Bat surveys along the whole scheme were commissioned and required YGC’s involvement to monitor the impact of the road and the potential success of culverts installed as bat passages along hedge and tree lines.

    Ecological watching briefs

    Watching briefs for species during the course of works, such as vegetation removal, initial soil strip, work near watercourses.