Water & Wastewater Treatment

16 | march 2015 | WWT | www.wwtonline.co.uk Roadbridge were the lead contractors on the project, which was finished ahead of schedule and under budget Project focus: pipes and pipelines unusual step of prebooking all haul- age up to three months in advance to ensure this was possible." The project was originally slated for completion by May 2015, but was brought forward by six months because of the area's high water table and the possibility of flooding in winter weather. "Because we were following the river valley, where it is prone to flood- ing, we had to finish the project by the end of November before the weather came in," continues Grimwood. "We had to work seven days a week to get it finished, and we were very fortunate Essex & Suffolk Water procured the concrete pipes for the project themselves "A lot of the design decisions were being made on site, and everybody put themselves out to make it work " Paul Grimwood, Essex & Suffolk Water • Innovations ● The project team were able to make use of 1km of abandoned pipe in the middle of the route, removing the need to lay new pipes in that area ● E&SW procured the concrete pipes for the project themselves rather than going through the lead contractor, saving around £1M ● A digger shield method was used for the two crossings of the River Chelmer, with a sha depth of 8m with the weather: it would have been a completely different job if we had tried it a couple of years earlier when we had the rains in 2012." The pipeline was completed in November and was operating success- fully by the end of that month, with ef- fluent running down its whole length. Overall, the project has increased the flow capacity of the pipeline from 828 litres per second to a minimum of 1524 litres per second. Although it is likely that further work will be required aŽer 2030 to duplicate the final 1km of piping nearest to the outfall, the design improvements made using the abandoned section of pipe in the mid- dle section mean that this area will not need to be revisited, negating the need for several million pounds in future work.

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