Main Onshore Pipeline

The Main Onshore Pipeline (the Pipeline), previously referred to as the HyNet Carbon Dioxide Pipeline, is a Nationally Significant Infrastructure Project which was granted a Development Consent Order (DCO) by the Secretary of State for Energy Security and Net Zero in March 2024. 

The DCO allows for the construction, operation and maintenance of the Main Onshore Pipeline as part of the HyNet Carbon Capture and Storage (CCS) cluster, where Liverpool Bay CCS Limited (LBCCS) is the Transportation and Storage (T&S) operator.

The Pipeline construction programme was launched in Summer 2025 by our Engineering, Procurement and Construction (EPC) Contractor, United Infrastructure (UI).

This webpage provides more information about the construction of the Pipeline. You can sign-up to our newsletter to be kept up to date about LBCCS wider activities and ongoing engagement with stakeholders and the community.

About the Pipeline

The Pipeline will transport CO2 from existing industry to the Point of Ayr terminal. From here it will be transported offshore to be stored in safe and permanent storage beneath Liverpool Bay. The CO2 will be stored in depleted reservoirs that have held natural gas for millions of years.

The Pipeline comprises three parts:

• 20” pipeline between Ince and Stanlow
• 36” pipeline between Stanlow and Flint – this is the current focus of the construction programme
• 24” existing pipeline between Flint and Point of Ayr – this is an existing natural gas pipeline that will be repurposed to transport CO₂

Interactive map

The interactive map shows the area within which the construction of the Pipeline will take place. You can move around the map to explore all elements that make up and support the construction of the Pipeline including the associated compounds, crossing points and Above Ground Installations (AGI) and the Block Valve Stations (BVS).

Construction of the Main Onshore Pipeline

Working hours

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.

Construction timeline

An indicative timeline for works is set out as:

What to expect along the route

The construction of the 36” Pipeline will be undertaken in key stages:

1. Pre-construction works (from Summer 2025)

Before we begin building the pipeline, you may notice some preparation work in the area. These activities help us keep the project safe, efficient, and environmentally responsible:

• Marking the work area – We’ll put up temporary fencing to show where construction will take place.
• Creating safe access routes – This includes clearing trees, vegetation and hedgerow as well as pruning trees along the route so vehicles can move safely, while protecting wildlife wherever possible. These works will help to ensure the pipeline route is clear for construction and construction vehicles can enter and exit safely.
• Managing water flow – Temporary drainage will be installed to prevent flooding during the works.
• Preparing the ground – We’ll create temporary tracks for vehicles and carefully remove and store topsoil so it can be replaced later.
• Delivering and preparing pipes – Pipe sections will be brought to site, welded together, and coated for protection before installation.
• Excavating the trench and installing the pipeline – Finally, the pipeline will be placed into the trench and secured. At trenchless crossings the pipeline will be installed into the tunnels.

2. Trenchless crossings

Trenchless tunnelling techniques bury the Pipeline deep beneath the ground, ensuring minimal disruption to key infrastructure, transport routes and environmentally sensitive areas.

Along the route there will be three methods of trenchless tunnelling taking place:

Micro-tunnelling (from October 2025)

Auger bore crossings (from March 2026)

Horizontal direction drilling crossings (from April 2026)

3. Specialist sections (from May 2026)

There are several sections where the Pipeline is surrounded by constraints such as roads, rivers or railway lines. In these areas a small, highly skilled and self-sufficient crew will construct the Pipeline in one go. The crews will usually complete all work within 4 to 6 weeks.

4. Above Ground Installations (AGI) (from November 2026)

An AGI provides a connection point along the pipeline where pipelines meet or CO2 capture plants connect to the T&S network. They allow for safe and efficient operation of the pipeline as well as for routing inspections and maintenance. More information about AGIs is available here.

AGIs will be built once all pipeline has been laid in the ground and buried but before the system is commissioned.

5. Block Valve Stations (BVS) (from January 2027)

BVS are part of the pipeline’s safety system. They isolate points along the pipeline allowing specific sections to be shut off for maintenance or monitoring. More information about BVS is here.

6. Commissioning (from March 2027)

Following construction, the pipeline will go through the commissioning process involving cleaning and testing to ensure it is safe and ready to begin operating.

The safety of the Pipeline 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.