Water & Wastewater Treatment

Organised by Supported by Co-sponsor EXPERT SPEAKERS INCLUDE Malcolm Horne General Manager, Asset Creation Waste Water Infrastructure Severn Trent Water Chris Jones Research & Development Manager Northumbrian Water Sonia Phippard Director of Water and Flood Risk Management Defra Keith Mason Senior Director of Finance and Networks Ofwat Dan Green Head of Sustainability and Innovation Wessex Water Piers Clark Commercial Director Thames Water Ian Barker Head of Water Land and Biodiversity Environment Agency Steve Kaye Head of Innovation Anglian Water Follow us @WWTlive using #waterinnovation BOOK NOW AT www.WWT-innovation.net The annual Water Industry Innovation Conference is a must-attend event for organisations seeking or providing innovative solutions to drive effi ciency within the water sector in AMP6 and beyond. Attend this one-day conference to: Gain fi rst-hand insight into Defra and Ofwat's role in breaking down barriers to innovation Explore the "adjacent possible" in the water sector and the new trends that are going to make a difference Discover new approaches to innovation measurement in the water sector and how it will impact the future Hear how your peers have overcome barriers and applied cross-sector innovation within their organisations Explore how your peers are taking a collaborative approach to innovation in AMP6 Find out about new developments within the supply chain during the "Technology Showcase" Charity partner Media partners 13 TH May 2014 | Holiday Inn Birmingham City Centre WIIC-2014-brochure-postearlyb.indd 1 13/03/2014 10:26 www.wwtonline.co.uk | WWT | APRIL 2014 | 39 In the know Technically speaking: Flooded sewerage A er the floods: cleaning-up sewerage systems "Once the flood waters are pumped away, there is a need for effective reinstatement of contaminated surfaces and recommisioning of the sewerage system" I n light of the recent and on-going flooding events, the discussion of how communities react to and recover from such catastrophic events is very topical. Although most of the debate in the national press has been about coping with or diverting the sheer quantity of water and the need to manage our flood plains to protect urban areas, there is another problem with flooding that has received less exposure and this is the effect on the drainage and sewerage systems of flooded communities. Sewerage systems in small rural communities typically comprise gravity drains, septic tanks and package wastewater treatment plants (WwTP). These are designed to incorporate the natural attenuation capability of field drains. In the current flooding events, these foul drainage systems have been overwhelmed. This creates immediate problems with the removal of wastewater from households and raises concern about contamination of floodwaters with untreated sewage. Once the flood waters are pumped away, there is a need for effective reinstatement of contaminated surfaces and recommisioning of the sewerage system. The scale and duration of the current flooding of the Somerset Levels is extreme, but knowledge and expertise exists, in the UK, with evidence-based guidance on the risks posed by contamination and protocols for clean-up and recovery available. Flooded infrastructure It will be necessary to remove silt from the pipes. This is a relatively easy (if laborious) process, typically carried out by carefully jetting the drains. All septic tanks should be pumped out and checked for structural integrity by looking for water leaking in from the ground. Depending on the tank design there may have been movement due to buoyancy or pressure from surface flows resulting in lids or tops being displaced or tank necks cracked; these should be replaced or repaired as appropriate. Septic tanks will recover func- tionality quickly but there may be an extended environmental risk if the drainage field remains saturated. All package treatment plants should be physically assessed as they may have lost power during the floods and could also have been physically affected. Again, repairs need to be MArk SMith Managing directOr, WRc Water surrounds flooded proper- ties in the village of Muchel- ney on the Somerset Levels near Bridgwater image:Steve Parsons/Pa

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