Severn Trent Water identified 400 properties in Newark-on-Trent, UK to be at risk of sewer flooding, prompting them to commit GBP60 million –their largest financial investment in one town – to upgrade and replace 12 miles of infrastructure.
The design and build contract was awarded to BNMA (an alliance between Barhale PLC and nmcn PLC) with civil design subcontracted to GHD.
At the heart of the project was a new 6500 L/s pumping station and screening facility, known as Crankley Point Terminal Pumping Station, at a site constrained by adjacent railways lines to the south and east. The design team was able to reduce the pump station diameter to 15m, which achieved a 25 percent saving in materials and 40 percent reduction in excavated material. In turn, this minimised traffic and the plan area. This was achieved by developing an innovative radial arrangement for the storm pumps, with the introduction of a central core, which rises out of the ground allowing the storm pumps to discharge toward the centre of the shaft and into a bowl on top of the central core.
Further benefits were delivered through the innovative design of the outfall to the River Trent, which utilised the existing storm tank outfall headwall rather than requiring a new one. Through liaison with the Environment Agency, a design was developed which involved strengthening the headwall and adding a stilling and combination chamber behind it. This avoided the need for a large cofferdam within the river which would have added significant health and safety risk and environmental impact.
The team worked collaboratively to arrive at a solution which took consideration of optimal mechanical and hydraulic performance, minimised the plan area and integrated temporary and permanent works. Each discipline’s experience, preferences, opportunities for value engineering were explored to develop an agreed design before commencing with a detailed design phase. This well coordinated design was highly successful, validated by a smooth construction phase with negligible problems encountered during the final build, through commissioning and handover.
The feedback from the client has been exceptional, from a senior management level down to the operations team working at Crankley Point on a daily basis. The praise from the operations team has been particularly rewarding; how easy they have found the TPS to work with post-handover and that everything is working as intended by design. The Newark Waste and Water Improvement Project was successful at the Institution of Civil Engineers 2019 East Midland Merit Awards Dinner winning the Large Project (£10m+) Award.