Thames Water has opted for early contractor involvement (ECI) on a major new scheme to upgrade its Deephams sewage treatment works.

Thames Water is planning major construction work at the plant as a result of what it describes as a step change in effluent discharge consent by the Environment Agency to meet European legislative requirements to improve river water quality.

The utility also needs to accommodate future population growth in the region to increase Deephams capacity  from its current population equivalent of 885,000 to a population equivalent of 941,000.

Thames Water say the step change in consent required by the Agency cannot be achieved by utilising the existing effluent treatment assets – requiring development of the main primary, secondary and tertiary treatment works either on-site or on a new site located nearby.

The existing Deephams inlet works, storm tanks and sludge treatment process will remain on the existing site. The treated effluent discharge point is to remain in its current location with flows discharging to Salmons Brook.

Thames Water has already appointed Planning, Design and Environmental Consultants to evaluate the strategic options for meeting the new consent and establish the preferred option. The initial development work is due to complete shortly and will be subject to the first phase of public consultation in 2012. Planning approval is not however anticipated before 2014.

The utility considers that Early Contractor Involvement prior to planning approval is necessary to enable innovative design and construction techniques to be incorporated into the scheme design at the earliest point and be included as part of the pre-application consultation process.

Thames Water now wants to appoint a contractor to take forward the development of the project, through the planning phase and into construction. The appointed contractor will take over responsibility from the Design Consultant for design inputs to the planning process and be responsible for detailed design of the new works including the process design.

The size of the Deephams Sewage Works catchment and the nature of the upgrade, which could require construction of a new off-site treatment works, mean the project has the potential to be classified as a “nationally significant infrastructure project” (NSIP) under the Planning Act 2008.

An application for planning approval for an NSIP project must be submitted to, and examined by, the Infrastructure Planning Commission (IPC), or its successor, and will be ultimately approved by the Secretary of State. The project is already listed on the Commission’s website as a pre-planning application.

In order to ensure the successful completion of the project, the Contractor will be expected to work in collaboration with Thames Water and the existing Planning and Environmental Consultants, supporting the pre-application consultation process and the successful approval of the planning application. Following approval, the Contractor will then be responsible for delivery of the scheme and handover to Thames Water.

In developing proposals for the replacement works, Thames Water wants to engage a contractor who will work collaboratively with Thames Water to deliver robust but innovative solutions to ensure that the landmark project can be delivered safely, on programme and within budget.

It is currently envisaged that the project will be delivered in three procurement stages.

A launch event for potential applicants is provisionally planned for 20.1.2012 in Reading, Berkshire. Interested applicants should email This e-mail address is being protected from spambots. You need JavaScript enabled to view it for further details and to make a reservation.

Time limit for receipt of tenders or requests to participate is 17^th February 2012. Click here to download the tender document.