United Infrastructure is the main contractor for the construction of the Pipeline.
United Infrastructure has over 30 years of experience delivering pipelines for the owners and operators of the UK’s gas transmission and distribution system.
To read more about United Infrastructure's experience in the Carbon Capture and Storage sector, head to their website here: https://unitedinfrastructure.com/services/carbon-capture-storage/
During construction, we will take all precautions to keep everyone safe. This includes complying with all UK Government legislation for CCS projects, infrastructure and operation. These are set out and regulated by the Health and Safety Executive (HSE) and the North Sea Transition Authority (NSTA).
There will be barriers around our temporary work areas and appropriate security in place.
As one of the conditions of the lease over landowners’ land, an easement around the Pipeline will be in place once it is installed. This is to prevent any development which could pose a safety risk to the Pipeline. Farm tracks and vehicles, however, will be able to safely cross over the Pipeline and existing agricultural practices can be resumed.
Once the work is complete, we will return the land as closely as possible to its original condition. We will replant or replace hedges or fences after construction where possible. The construction is supported by an Environmental Management Plan (EMP) and Construction Traffic Management Plan (CTMP).
- EMP – sets out the overarching management measures that seek to avoid and/or reduce potential environmental impacts during construction, as well as during operation and decommissioning stages.
- CTMP – sets out the measures to ensure any movement of plant or equipment is conducted in a safe and efficient manner, while minimising disruption to local communities. It will be continually monitored, reviewed and improved throughout the construction stage to ensure measures are being adhered to and that they remain appropriate throughout the construction stage.
Work and deliveries for the Main Onshore Pipeline will only take place within core working hours, which are:
- 8am to 6pm Monday to Friday
- 8am to 1pm on Saturday
The consent also allows for one hour either side of these times for site set up and close from 7am to 8am and 6pm to 7pm Monday to Friday and 7am to 8am and 1pm to 2pm on Saturdays.
If work needs to take place outside normal hours, we’ll agree this in advance with the Local Authority to minimise disruption and will keep you informed. Trenchless crossing techniques require working 24 hours a day to ensure the safety of the tunnel and the construction team. More information about 24 hour works is available in this factsheet.
There are two key methods that will be used to construct the Pipeline. These are the open-cut trench technique and the trenchless technique.
The open-cut trench technique will involve digging soil to form a trench, lowering the pipe into the trench, and backfilling it with the excavated soil. The depth of the trench will vary depending on technical factors such as ground conditions and topography. The minimum depth of the trench to the top of the pipe will be 1.2m.
Trenchless techniques are used when installing pipelines under railway lines, major roads and riverbeds. Trenchless techniques bury the pipeline at a greater depth than the open-cut technique and will depend on the nature of the feature being crossed. In these cases, we will use methods such as:
- Horizontal Directional Drilling: Horizontal directional drilling (HDD) involves drilling a pilot borehole under the surface. The pipe and or casing is then pulled back through the borehole.
- Auger boring: Auger boring installs a pipeline under the ground by pushing a steel casing or tube through the soil while a rotating helical auger (spiral tool) brings the soil out of the casing.
- Micro-tunnelling: Micro-tunnelling uses remotely operated machines to install pipes underground. The process involves pushing a pipe through the ground while the soil is being excavated simultaneously at the machine’s cutting head.
1. Roads
To avoid disruption to major roads, railways, canals or rivers, the Pipeline will be constructed using a trenchless technique, meaning that major roads will not need to be closed.
Trenchless techniques bury the pipeline at a greater depth than open cut methods and allow for installation while the road, railway, canal or river remains open.
2. Noise
The impact of construction noise and vibration will be kept as low as reasonably practicable by undertaking all work in accordance with BS 5228-1:2014 – Code of practice for noise and vibration control on construction and open sites.
Mitigation measures will include:
- The use of machinery that conforms to the relevant noise emission standards, for example white noise reversing alarms. Additionally, where possible electrically powered plant and machinery will be used.
- Use of acoustic barriers, screens or covers where required. Additionally, acoustic enclosures will be set up around static plant to reduce noise disturbance.
- Works which would have higher noise levels will be scheduled for times that will have the least impact on the local area. Some locations where trenchless crossings are being carried out will require working 24 hours a day, but this will be for short periods.
- There will be 24-hour noise monitoring that will trigger and notify the construction contractor(s) at the centralised compounds and where there is a potential impact outside of core working hours at trenchless crossings.
- If necessary, enhanced mitigation measures will be agreed with the appropriate Local Authorities and communicated accordingly.
3. Dust
Dust emissions will be carefully monitored and managed by the construction contractors onsite.
All work will be carried out wherever possible in accordance with best practice codes of conduct such as the Control of Dust from Construction Sites (BRE BTi Feb 2003).
Mitigation measures include:
- Stripping and stockpiling of soil shall be kept to a minimum. Where stockpiling is required, they will be covered, seeded or fenced to prevent wind whipping.
- Site layout will be planned to keep machinery and dust-causing activities away from the community.
- Dust suppression measures will also be in place and will include:
- Bowsers to dampen surfaces in dry weather
- Wheel washers to limit dust being tracked off-site by construction vehicles
- Solid screens shall be put up around dusty activity or the site boundary where possible
- If necessary, works will be stopped or postponed if dust levels are too high, for example during dry or windy weather
4. Environment
As part of the pre-construction activities, surveys are being conducted to understand the ecological and environmental sensitivities of the site. Ecological surveys will consider badgers, bats, water voles, otters, great crested newts, fish, barn owls.
All surveys and construction works will be overseen by a third-party Ecological Clerk of Works (ECoW) who will oversee pre-construction surveys and monitor ecological conditions during construction. The ECoW will also monitor the implementation of mitigation measures and ensure all site personnel are working appropriately.
Carbon dioxide transport pipeline
The Pipeline has been designed to comply with well-established codes and standards, the applicable UK Regulations (including the Pipelines Safety Regulations 1996) and industry best practices. Together with detailed safety assessments, operation and integrity management systems, these will ensure the potential for any leakage of CO₂ is minimised and risks are as low as reasonably practicable.
All pipelines in the UK operate under strict UK regulations (Pipeline Safety Regulations 1996) and industry standards, such as the Institution of Gas Engineers and Managers Technical Document 1 (IGEM/TD/1), which sets out design, construction, and operation requirements for high-pressure pipelines. The 'main onshore pipeline' will be managed to these same requirements as existing gas pipelines already in place across the country.
Mitigation is built into the design and operation of the pipeline to ensure risks are managed to be As Low As Reasonably Practicable (ALARP). Engineering and Design Safeguards have been adhered to including hazard studies (a programme of hazard identification and risk assessments to inform an inherently safe design), good engineering practice (all plant, drainage systems and equipment will be designed and installed to meet industry safety standards) and intrinsically safe equipment.
Once installed, the pipeline will be subject to regular maintenance checks in line with regulatory requirements.
The Pipeline incorporates inbuilt safety mechanisms, such as block valves at intervals to isolate sections quickly, in the unlikely event of a major accident. A formal Emergency Response Plan will be in place for such an event.
Carbon dioxide storage
Gas has remained safely trapped in geological structures such as sandstone reservoirs, like the ones in Liverpool Bay, for millions of years. These reservoirs are deep below the surface of the seabed. The Liverpool Bay CO₂ store will be up to 1km below the seabed and approximately 20 miles offshore. Hundreds of metres of shale lie over the top of these sandstone reservoirs, making an impermeable layer which traps the gas in place. The CO₂ will be stored in the same way as the original natural gas and will remain safely contained in the depleted natural gas reservoirs.
Regulations
LBCCS has extensive experience designing, building, and operating safe and effective high-pressure gas pipelines and it will use this expertise to develop the Pipeline to the highest safety standards.
The UK is home to a range of high-hazard industries and has developed a world-class safety regulatory regime. The UK Government regulates all CCS projects, its infrastructure and its operation. The safety of the Liverpool Bay Transport and Storage Project will be regulated by the Health and Safety Executive (HSE) and the North Sea Transition Authority (NSTA). Both regulatory bodies have a long track record of effectively regulating safety in the UK hydrocarbon sector.
Monitoring
LBCCS will carefully monitor the Pipeline, throughout all the operation phases, CO₂ transportation, injection and safe containment within the reservoir, using state of the art techniques.
Monitoring
To ensure the safety of the offshore storage under Liverpool Bay, a programme of monitoring, measurement and evaluation will assess the behaviour and integrity of the CO₂ throughout the planned 25-year life span. This will include advanced methods such as geophysical surveys, pressure sensors, seabed surveys and specialised monitoring wells.
Monitoring and maintenance of the Pipeline will be regularly performed. The Pipeline network will be fitted with leak detection systems with early warning and remote identification ensuring that it can be safely managed in the event of any leakage.
LBCCS will carefully monitor the Main Onshore Pipeline, throughout the planned 25-year life span including through all the operation phases, CO₂ transportation, injection and safe containment within the reservoir, using state of the art techniques.
Operation and maintenance
Once the Pipeline is operational, it will not require permanent staffing or personnel presence. The BVS and AGIs will be operated remotely and controlled from the Point of Ayr Terminal in Flintshire. However, the AGIs will allow for in-person operation when required and will include emergency shut-down valves. As there will be no onsite power-generating equipment at the AGIs, the only active source of noise is expected to be the Electrical and Instrumentation Kiosk, which will be mounted with air conditioning units.
Routine maintenance of the AGIs is expected to be minor and consists of lubrication, and calibration of instruments.
Decommissioning
The infrastructure for the Pipeline is designed for a lifespan of 25 years. Once it has ceased to be operational, the Pipeline will be decommissioned safely, filled with nitrogen and left in-situ. Nitrogen is an inert gas which prevents corrosion of the Pipeline.
The above-ground facilities associated with the AGIs and Pipeline will be decommissioned and preserved in line with industry best practices and facility owner requirements at the time of decommissioning.
During the course of the construction programme for the Main Onshore Pipeline, our construction contractor, United Infrastructure (UI), may need to implement temporary traffic management measures to ensure the safety of the community and operatives on site.
These measures also aim to keep traffic flowing as freely and as safely as possible while construction is taking place.
Temporary traffic management measures may be required for short periods near temporary construction compounds and the associated access tracks.
Measures might include:
- Temporary diversions and closures of Public Rights of Way (PRoW) where they interact with the construction traffic routes. These will be agreed with Cheshire West and Chester Council (CWCC) and Flintshire County Council (FCC) in advance.
- Traffic control measures to manage traffic at temporary access points, such as priority signs, stop/go boards or portable temporary traffic lights along with additional approach signage to reduce speeds.
Where required all temporary traffic management measures will be signposted at least three working days prior to the measures being implemented. The notice period will depend on the amount of time the measures will be in place for. Within Wales, any signs will be bi-lingual, in line with the Welsh Language [Wales] Measure 2011.
All traffic and road data is recorded by CWCC and FCC on their respective interactive maps. To find out more about the potential traffic management measures near you please visit: