LEWES SEWERAGE IMPROVEMENT, EAST SUSSEX
For projects that involved processes adopted to understand and meet client needs, supported team working throughout, and maintained continuous improvement. Sponsored by May Gurney.
Sewage flooding through streets and watercourses was the curse of Lewes, a beautiful historic town squeezed into a steeply sloping chalk landscape.
Lifting the curse involved boring a substantial, tunnelled storage tank closely embracing the town and then plumbing it into the old combined sewer system. Noxious sewage is now pumped from the tank in a controlled manner so it can be treated properly and released as clean efuent.
In essence the project is a typical but extreme example of sewerage engineering. What is outstanding, and left a huge impression on the judging team, is the way that everyone involved worked together to produce the best possible result.
Digging open trenches, deep shafts and tunnels in close proximity to narrow streets lined with delicate old buildings could easily have resulted in misery for residents and massive claims on the construction team.
Minimising the risk, reducing excavation and controlling cost began with analysis and detailed reanalysis to hone the hydraulic performance of the proposed new sewer network. It was continued by applying the most up-to-date mechanised techniques for shaft sinking, pipe-jacked tunnelling and directional drilling; checked on by real-time remote monitoring; and publicised to residents through a very active neighbourhood campaign.
THE TEAM Client Southern Water Services Cost £14.93 million Principal designer and contractor Black & Veatch/Costain JV