The pipeline route

This stage of the Milford Haven Gas Connection Projects starts at a new compressor station at Felindre, near Swansea. Planning permission for this compressor station was granted in November 2006 and it is due to be commissioned during 2009.

The pipeline, which is now complete and in use, leaves Felindre in a north westerly direction, crossing the River Loughor and then going north, following the A483 from Ammanford to the north west of Llandeilo. It then crosses the River Towy, traverses the north west of the town and follow s the A40 north east, crossing the River Towy again to the north of Llangadog.

The pipeline then travels east towards Brecon, before turning north to follow the A470 and A438 to Hay-on-Wye. It travels south east in the direction of the B4348 to where it crosses the A645, continuing south east to re-join the existing National Gas Transmission System (NTS), at a new above ground installation (AGI) at Treaddow, near our existing Peterstow compressor station. It then moves eastwards, north of the M50, passing under the M50 near the Newent junction (J3), and continues eastwards to connect again with the NTS near our existing AGI at Tirley, between Newent and Tewkesbury in Gloucestershire.

• Felindre to Tirley Pipeline Route Map

Choosing the route corridor

An extensive area covering some 5,300 square kilometres was reviewed to identify pipeline corridor options. This area included a number of significant restraints - for instance, the Brecon Beacons National Park, the Blaenavon World Heritage Site and Sennybridge Military Training Area - in addition to those areas that would normally be avoided, such as built-up areas of settlement.

A number of potential corridors were identified and investigated, to enable us to obtain relevant archaeological, ecological and environmental information. Early consultations were also undertaken with key statutory bodies, such as the Countryside Council for Wales, English Nature, the Brecon Beacons National Park Authority, the Environment Agency (in Wales and England), Welsh Assembly Government and Blaenavon World Heritage Partnership.

Following these consultations, and taking into account construction difficulties, the significance of environmental impacts and ease of restoration, the preferred pipeline route corridor emerged, running between Felindre and Tirley and passing through the very northern part of the Brecon Beacons National Park.

Consultations continued with a wide range of organisations, local government, landowners and other individuals to refine the route and undertake an Environmental Impact Assessment (EIA). The EIA informed the Environmental Statement, which was included with our application for consent to build the pipeline, submitted to the Secretary of State for Trade and Industry in August 2006.

Consent to construct the pipeline was granted in February 2007. Construction was completed late in 2007, although reinstatement works continued in certain areas in 2008.

Above ground installations (AGIs)

In addition to the new section of pipeline, AGIs were required at intervals on the route to accommodate valves and other essential plant and equipment for the operation of the pipeline. AGIs at Treaddow and at Three Cocks, near Brecon, are now complete, but planning permission was refused for a Pressure Reduction Installation (PRI) at Corse, near Tirley. A PRI in the Tirley area is required for the pipeline to operate at full capacity, and National Grid has now submitted a new planning application for a different site.

Please see the page about Tirley Pressure Reduction Installation for more information.