Major Contract In Liverpool

14 March 2013

Costain is involved in a major project in Liverpool’s Docklands as it seeks to ensure that the city’s efficient treatment of waste water continues uninterrupted into the future.

As part of a consortium with Galliford Try and Atkins it is now well into a £200 million contract for United Utilities (UU) to upgrade and expand Liverpool Wastewater Treatment Works (WWTW) at Sandon Dock.

The existing WWTW equipment has a limited remaining asset life and is in need of upgrade, says Andy Fielding, Costain’s Construction Manager on the project. Costain, with its partners GallifordTry, Atkins and United Utilities, has undertaken refurbishment work to keep the plant performing, but more substantial measures are required.

These will include replacing many plant items including the current inlet pumps, which lift wastewater from sewer level, with larger, more robust machinery. Other improvement works will extend the existing plant’s usage for a further 15-20 years. The existing site has to remain operational throughout all these works.

In order to ensure process reliability, the WWTW will be extended into the neighbouring Wellington Dock. This dock has been dredged and filled with sand. After sand fill around 1000 concrete piles 20 metres long are being sunk to the bedrock under the dock. The new dock area will be used to build a new SBR (Sequencing Batch Reactor) process tank and will sit as a ‘floating’ construction, atop the capped piles.

To make maximum use of the available space, the SBR will be double stacked and is fed from a new SBR feed pumping station to high and low level distribution chamber.

In addition to the SBR there will be a new sludge treatment facility housed in a single treatment building on the adjacent dockside. The sludge is used to feed the existing MAD plant which generates gas from the sludge as fuel for a CHP unit which can generate 1-2MW of electricity.

Construction work is currently 20% complete and forecasting a completion award of the PIU (plant in use) of August 2015.

The team will peak at 100 staff and approximately 250 operatives. The project team recently celebrated 500,000 man hours without RIDDOR.

Darren Dobson, the GCA lead for Liverpool WWTW remarked: “This large complex project is being delivered in partnership with our client UU. Our performance to date has been excellent and the team is now set up to ensure the project is successfully delivered and we achieve our project goals.”