Case Studies

Preseli Pumping Station

OCU delivered the upgrade of pumping and control infrastructure at Preseli Clear Water Pumping Station, which supplies treated water directly into the distribution network.

Tafarnaubach Trunk Main Renewal

OCU delivered the emergency replacement of the Tafarnaubach trunk main after a landslide during Storm Dennis caused failure of a 600mm water main supplying the local network.

Pen Y Ball Pipeline

OCU delivered the construction of a 5.2km clean water pipeline between Lixwm and Pen Y Ball Reservoir in North Wales.

Bredenbury Pressurised Pipeline System

OCU delivered the Bredenbury Pressurised Pipeline System for Dŵr Cymru Welsh Water as part of its Main Network Renewal programme.

Grandstand Road Slip Lining

OCU delivered a distribution mains renewal programme for Dŵr Cymru Welsh Water, installing 9.3 km of new mains following investigations into existing distribution assets.

Brynmoelddu pressurised pipeline system

OCU delivered the Brynmoelddu pressurised pipeline renewal scheme for Dŵr Cymru Welsh Water, replacing an existing asbestos cement main using pipe bursting and installing 1,120 m of MDPE.

Axford Pipeline Thames Water

OCU was appointed to deliver the Axford Pipeline scheme for Thames Water. The project involved constructing a 17.6km clean water pipeline, building a new booster station at Dorcan.

Vyrnwy Aqueduct Modernisation Programme

The Vyrnwy Aqueduct programme involves a major refurbishment of one of United Utilities' oldest and most strategic clean water assets. Phase one, completed in 2024, included cleaning, seal repairs, and new valves on Line 3. The project is scheduled to be finished by 2028.

Customer Focused Framework Yorkshire Water

Yorkshire Water appointed OCU to deliver key works under its Clean and Waste Infrastructure and Customer Focused Infrastructure Frameworks, part of the £650m AMP7 investment programme (2020-2025). Following a strong performance, OCU secured a four-year extension into AMP8.

Water Retaining Structures
(WRS) Framework Affinity Water

Delivering new service reservoirs under the WRS Framework for Affinity Water’s Strategic Supply 2040 Programme, increasing storage capacity and strengthening water supply resilience across Bedfordshire and Hertfordshire.

Network Maintenance Services
United Utilities

Providing specialist network maintenance under Lot 8 of United Utilities’ framework, delivering complex repairs to noncore clean water assets including aqueducts and pipe bridges, with key works such as the multi-year refurbishment of the historic Lake Vyrnwy Aqueduct.

HS2, Old Oak Common
Enabling and Multi Utility Diversion Works

Delivering multiple utility diversion packages at Old Oak Common Station, including water, gas, regulated power and telecoms, enabling construction of the HS2 transport superhub in West London.

HS2 Infrastructure
Enabling and Multi Utility Diversion Works

Delivering utility diversions across water, gas, power and telecoms for a major UK rail project, with our Water and HDD teams applying NIRS, GIRS and WIRS accreditations to complete complex works in constrained environments.

Capital Major / Minor Mechanical and Electrical Frameworks

Delivering clean and wastewater projects as a Capital Alliance Delivery Partner for Welsh Water under AMPs 8 & 9, building on over 15 years of partnership and framework support across pipelines, mechanical and electrical works.

Capital Delivery Pressurised Pipeline Framework Welsh Water

Longstanding delivery partner on Welsh Water’s Pressurised Pipe Framework since 2012, delivering mains rehabilitation, planned and emergency trunk main works, HDD river and rail crossings, and 24/7 support for complex reactive repairs.

Cork Harbour Horizontal Directional Drilling

OCU was contracted to design and install twin 1,025 metre lengths of 500mm Diameter SDR-9 PE100 Foul Main under Cork Harbour using Horizontal Directional Drilling (HDD).

Dee-crossing Connah's Key

OCU was awarded the Dee Crossing contract, located in Connah’s Quay. Our teams designed and installed two 860m-long barrier pipelines under the River Dee using Horizontal Directional Drilling (HDD). 

Modular Storm Tanks - SW Water

OCU took on the emergency job of the installation of several modular storm tanks at 3 different live site locations to meet key WINEP dates for SWW compliance to the EA for 2024 in a 12-week window as PC and PD for SWW at their request in Devon.