Another part of the project, where the offsite build was key, involved our work on the sludge pumps and skids. The versatile approach that the project team used here was fabricated in a factory, completely tested, and delivered to the project site, where it was simply dropped into place atop the in situ base slab. The best part? It only required a few hours to install. We even developed a modular, infinitely expandable and adaptable aboveground design for the Motor Control Centre (MCC) kiosk, which was also developed and built offsite and placed on an in situ slab, where it serves as the electrical and instrumentation brain that drives everything onsite at the sewage treatment facility. This MCC design is now being adopted across Northumbrian Water’s framework, and other water companies are expressing interest in it, too.
For the four new settlement tanks, the original tender period we were given, using in situ concrete, was a timetable of 21 weeks excluding all metalwork, bridges, and scrapers. Because we decided instead, to fabricate the tanks from stainless steel, the entire process – from the very start to completely installed onsite – was only six weeks. The supplier also provided one-stop services, including design, civils install, and the supply and set-up of the access metalwork and scraper bridge.
The lessons learned were many
From the very beginning of this project, we set out to challenge the status quo – to seek new ways, and a more sustainable approach, to what is an age-old issue: sewage treatment and the facilities we build to make that happen. For a project that was originally tendered and awarded based upon traditional reinforced concrete structures, the full project team worked together to collaboratively embrace the use of innovative solutions that broke new ground – and new ways of thinking – across several work packages.
By fabricating everything needed for this project offsite, we achieved a substantial reduction in the carbon emissions long associated with this work. On top of that, we also cut our time onsite by 20% overall and man-hours by 47% specifically. This, in turn, also improved our overall safety performance. These achievements are even more exemplary when you consider that the project was delivered during the height of the COVID-19 pandemic, which required adherence to strict social distancing constraints during construction.
Additional takeaways from the project include greater predictability in delivery times and the fact that our work caused less disruptions to daily operations at Northumbrian Water’s Wolsingham facility, as well as within the residential communities nearby.