Howdon STW Upgrade

Description

This project covers the design, construction and commissioning of the Howdon STW upgrade which is required to achieve the new consent requirements associated with the expected population growth. Howdon STW treats wastewater from the Local Authority areas of North Tyneside, Newcastle, Gateshead, South Tyneside, and parts of South Northumberland. Across these five Local Authority areas, Howdon STW serves a domestic population of around 840,000, with trade effluent flows increasing the population equivalent to around 945,000. As much of the sewer network within the catchment is combined, surface water also contributes to the Howdon flows. There are potential limitations on any new housing developments due to sewage pumping and treatment capacity within the Tyneside catchment. The most viable solution is to expand the treatment capacity at Howdon. The recommended solution comprises of: • Upgraded primary tanks • New storm tanks (with odour control) • Upgraded secondary treatment • New final settlement tanks • Upgraded UV treatment • Upgraded primary effluent and south bank pumping stations (improving the resilience of the site) Although there is insufficient space on the existing STW to fully complete this upgrade, there is a vacant site adjacent to Howdon which is available. Negotiations to purchase this site are at the final stage. Delivery of this project has been phased, with Phase One reflecting the minimum required scope for AMP7 Phase One (due to complete by April 2025): • Purchase of additional land to accommodate the above works • New storm tanks • Upgraded primary effluent and south bank pumping stations (improving resilience of the site) Phase Two (due to complete by April 2027): • Upgraded primary tanks • Upgraded secondary treatment • New final settlement tanks • Upgraded UV treatment The upgrade of Howdon STW will support NWG's corporate goals of having the best rivers and beaches in the country and, having zero pollutions as a result of our assets and operations, falling under the 'improving the environment' key theme. Value of Contract: £80,000,000 - £95,000,000 Lot 1: The procurement strategy is still under development, but is likely to comprise: • Design and Construct Contract to complete the Works in two phases • The development also requires some demolition which could be included in the main contract if advantageous to all parties. The outline programme comprises: • Launch/Engaging supply chain/PQQ, April 22 • Tender Period, June to Dec 22 Including a menu style pricing schedule • Contract award April 23 • Phase 1 Completion April 25 • Contract completion April 27 NWL are focused on ensuring the most efficient delivery, whilst meeting all quality and programme drivers. Alternative procurement approaches will also be considered. What is important to us; • Fully Integrated Team (design, construction and commissioning) • Openness - working together to solve problems • Robust Programme - shared continuously so there are no surprises • Process Guarantees • Track record in innovative treatment process • Working together to agree robust scope with no ambiguity • Confidence in site information • Minimising carbon impact during construction (and ensure design can be optimised to reduce operational carbon) • Positive Impact on Howdon STW's advanced anaerobic digestion plant to be maximised • Commissioning experience to minimise disruption to Operations (interfacing with existing treatment processes) and always assuring compliance with Howdon STW consent • Consideration of legacy, natural capital solutions