Crosshills Service Reservoir No.1

Installation of 'Intelligent-lite' roof membrane
CLIENT
United Utilities
PROJECT TYPE
Clean Water
DATE COMPLETED
March 2017
VALUE
£1,441,713
PRINCIPAL CONTRACTOR
Eric Wright Water
FORM OF CONTRACT
NEC ECC Opt A

Overview

Crosshills SR No.1 is a 140 mega-litre hexagonal shaped, covered water storage tank (service reservoir) that serves in excess of 250,000 customers within the Wirral area.

It is a critical asset for United Utilities as it provides ‘clean’ water storage for distribution to domestic and industrial customers and ensures security of supply during annual peak demand periods.

Eric Wright Water Ltd were appointed by United Utilities Plc as Principal Contractor to install and commission an ‘intelligent-lite’ membrane across the entire roof structure of the reservoir to prevent water ingress. The project involved the excavation and removal of the existing grass root system and topsoil (by hand) forming the overburden to the reservoir roof to allow the installation and commissioning the membrane system.

In tandem, a new surface water drainage pipe network was required for the top and perimeter of the service reservoir (including connection to the existing outfall pipework). Following the installation of an “intelligent-lite” membrane, the excavated overburden on the SR roof was reinstated and grass seeded.

Additional works included:

  • Installation and grouting in-situ of (DWI approved) slip lined pipework to sections of the outlet pipework
  • Excavation work to a section of the SR embankment to facilitate a survey of the existing inlet pipework.

Key Challenges

The reservoir roof structure was deemed ‘fragile’ by the client and mandated that a loading limit of 200kg (concentrated load) was not to be exceeded for both the temporary and permanent loading cases.

This meant that the only means available to remove and replace the overburden was by manual (hand) excavation techniques using shovels and wheelbarrows. As the contract was awarded in October and completed over the winter months, a key challenge was to ensure the safety (slips, trips and falls) and wellbeing of the workforce as the work progressed.

Added Value

Close review of the roof membrane options at tender stage and the identification of an ’intelligent-lite’ solution by our supply chain partners which afforded considerable savings to the client over the fully intelligent  option.

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Get in Touch

For all enquiries, please get in touch with the team here at Eric Wright.