The proposed framework will support the assessment, design, supply, installation, commissioning and replacement of diffuser systems within Activated Sludge Plants (ASPs) and associated wastewater treatment processes.

The framework is intended to provide end-to-end scheme delivery, including:

Current estimated start and end contract dates are 1 January 2027 to 31 December 2030 with further possible extension options up to 31 December 2034.

The framework will operate on a multi-supplier basis, with Yorkshire Water awarding call-off contracts either with or without competition in accordance with the procedures set out in the Framework Agreement. Prices for call-offs will be determined using the pricing schedules established at tender, with the ability to confirm or adjust pricing where permitted by the call-off process.

Call-off contracts may be awarded either directly, where the framework provides an objective method to identify the most suitable supplier for a defined requirement, or following a further competition among the suppliers appointed to the framework.

Deadline for requests to participate is 11:59pm on 12 August 2026 and current estimated award decision date is 20 November 2026.

Yorkshire Water will run the following multi-stage procurement:

Interested suppliers submit a COP Questionnaire. Responses are assessed against defined pass/fail Selection Criteria to determine whether suppliers meet Yorkshire Water's minimum requirements. Yorkshire Water may conduct one or more rounds of selection and reserves the right to shortlist suppliers progressing to subsequent stages.

Shortlisted suppliers will be invited to review and, where permitted, comment on the Proposed Contract. Yorkshire Water will refine and finalise the contract terms during this stage. Only suppliers who accept the final contract terms will progress to the ITT stage.

Suppliers will submit detailed quality and commercial tenders, which will be evaluated in accordance with the award criteria set out in the ITT documentation.

The procedure structure and indicative timelines are set out in the procurement documents.

Tenders must be submitted electronically via SAP Ariba, Yorkshire Water's e-procurement portal. The water company is now inviting suppliers with relevant experience and capability to express interest and participate.

Suppliers will not be able to view or access the tender in SAP Ariba unless they have been invited by Yorkshire Water through the portal. Suppliers who would like to participate but are not yet registered as a Yorkshire Water supplier are asked to email:

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and include the full legal company name and the email address they want to register. They will then be issued with a registration request and an invitation to the tender via SAP Ariba.

Suppliers already registered as a Yorkshire Water supplier but who have not received an invitation, are asked to email

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and include their ANID number, full company name and registered Ariba email address, so that an invitation to the tender can be issued.