arc21 has been considering options for the treatment and energy recovery/disposal of residual waste from its constituent councils to cover the period until arc21's envisaged long-term residual waste treatment solution is operational. In June 2021 arc21 undertook a market engagement exercise to help inform its decision making process. The decision-making process has now been completed and, on 7 December 2021, the arc21 Joint Committee approved a document entitled "arc21 Residual Waste Treatment Interim Services - Decision Document". The Decision Document is being published to inform the public and the market of the decisions reached by arc21, and its intention to proceed to commence a procurement competition on the basis of the details set out within the document following expiry of a 3-month period. The Decision Document contains details of a number of decisions taken by a public body (namely arc21 and its constituent councils) concerning the future arrangements for residual waste within the arc21 region in the period until the Residual Waste Treatment Project is operational, and the procurement procedures to be used to implement those arrangements. Any challenge to the decisions, positions and approach set out within the Decision Document must be commenced by way of judicial review and be brought within 3 months of the date the decisions were made (and the document approved) by the arc21 Joint Committee.