Water & Wastewater Treatment Magazine
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22 | JULY 2019 | WWT | www.wwtonline.co.uk The Works: Sewer networks rather than waiting for a formal report, they would send out an email to the team as soon as any key risks were highlighted (Yates recalls one email, highlighted in red, that warned: "Whatever you do, don't dig"). They targeted the areas with the most pressing deadlines, keeping a UXO spe- cialist on site to carry out a watching brief as the digging work took place. "Our supply chain really stepped up," Yates says. "It involved working at very late notice sometimes, with a phone call at 4pm to be onsite the next day at 8am to enable digging and weekend working." The archaeological experts were also present onsite while the trenches were excavated, and an ecologist looked on during the early phase. "At times, we had our delivery partners and their crews doing the construction work being watched for unexploded munitions, watched for archaeology and at one point watched for ecology as well," Perkins says. "It's probably not what they were used to but it was what was required." The approach paid dividends: con- struction work to lay the new main began on 1 March, and the work within Manston Airport was completed by 25 March. Their task was eased a little by the fact that much of the main working area had already been cleared through previous projects, but the final report, based on ground-penetrating radar, found that there had been 31 anomalies that could have been unexploded ordnance within the workspace. The report also showed there had been 200 high-explosive drops previously recorded within 500m of the workspace. "It was a'er we'd got out of the airport that their official report came through," Perkins says. "That's how out of sync with the cycle we were." Had any significant unexploded ord- nance been uncovered during the excava- tion work, that could have dealt a decisive blow to hopes of finishing on time. As it turned out, the worst that they uncovered was an old cast-iron fireplace. "We were fortunate," Yates says. "We did the right things at the right time and the right speed that meant we were able to continue. That said, two weeks a'er we were given the all-clear from our special- ist, the works on the airport found a 40kg bomb that needed dealing with..." The presence of the archaeologists also proved worthwhile, finding evidence of the prehistoric occupation of the land, includ- ing waste products of flint tool-making from the Mesolithic period (10000-4000BC) and other finds from the Early Iron Age (800- 400BC) and Roman periods. "There's pottery and ditches and scorch marks from fire pits," Yates says. The sewer was eventually connected in on 15 May – the day the bathing water season officially started – a'er being held up for a week by weather problems, but otherwise the team managed to achieve all of their targets against some formida- ble challenges. "The key for me was the format of the project team, with the skills from the dif- ferent camps working towards a common objective," Perkins says. "We delivered it extremely quickly and we did it in a safe way despite all the constraints. It was stressful but, because we were all on the same page, it didn't feel overwhelmingly stressful. "Ultimately, although Brexit didn't happen at the end of March, the Depart- ment for Transport were happy that we fulfilled all our obligations, we almost hit the bathing water date, and the par- ish council and local community have been fantastic." The team works within Manston Airport, with the connection diverting to the new main being installed to the air valve chamber One of the dog legs on the new mains path