Water & Wastewater Treatment Magazine
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16 | MARCH 2017 | WWT | www.wwtonline.co.uk where phosphorus permits from a number of Wessex treatment works were combined into one overall P permit, which could then be brought down by a small number of more significant improvements. The second is at Poole Harbour, where the water company has incentivised farmers to reduce their discharges of nitrogen into the watercourse instead of water company treatment upgrades that would have been more expensive. Although the latter approach has only thus far been used for nitrogen, it could be just as applicable to phosphorus. There is no question that catchment management could be effective in reducing the level of phosphorus in a watercourse but the obstacles to be overcome here concern how such schemes are administered, says Mark Worsfold, Director of Asset Management at South West Water. "We're at a very interesting crossroads in terms of catchment management. On the drinking water side, it's proven and the benefits of it are well understood; but we've then got river basin planning, and the whole flood agenda. All three of those have to come together now, so catchment management is moving beyond looking at a single parameter or a multitude of parameters… it's no good trying to solve wastewater problems only to find that you have increased flood risk downstream, for example. So all these things have to be looked at in the round. "The biggest problem we've got is a political one. It's 'Whose catchment is it anyway?' and who's in charge. Who should take the lead, who should pay and who should be paid - and where does that money come from? And what is the role of the farmer and the various landowners, because ultimately, they own the land and we've got to incentivise good practice and good behaviour across those catchments." Britain's exit from the European Union and the move away from Common Agricultural Policy payments could provide the impetus for change in this area, agreed participants. While it is extremely unlikely that environmental standards on P and other nutrients will be relaxed, there may be more flexibility in post-Brexit UK to look at different and more creative ways of meeting these standards. Gordon Reid, Wastewater Strategy Asset Strategy at Scottish Water, added that Brexit could even mean that the industry adopts a 'watch and wait' approach, reviewing the effect of previous improvements and the evidence base before spending large amounts of money achieving very low levels of P. The Water Framework Directive is all about achieving good ecological status, and since chemical improvements in a river might take 6-12 years to affect its ecology, it is possible in time that the current level of P removal may prove sufficient, he suggested. However, with phosphorus being a finite resource due to be exhausted in the space of decades, he called for more of a focus on phosphorus recovery and not just removal. "In the context of Scotland, where our population centres discharge into the sea or estuaries, I've got no regulatory driver to talk about wastewater P," said Reid. "But that's where the bulk of this limited resource is going - straight into the sea, and it's gone. I don't think there's enough activity going on across the sector, academic as well as industrial, to look at how on a large works discharging to the sea could you feasibly and economically recover that P. It's maybe not a challenge that we need to address now, but I can see it coming in a couple of AMP periods time." Summing up the discussion, Nizar Ghazireh, Head of Research & Development at Tarmac, says: "P removal is a huge, national problem, which every single water company has got to address one way or the other. We've heard today about some of the technologies that are being trialled. But we've also talked about how the development of new innovations in the water industry typically takes 20 years, which is a very long time to wait. Other sectors are able to achieve this quicker, and so I think there's a real question around how we accelerate innovations so we are making a real difference in five or ten years, and not passing the problem on to the next generation." Round table participants Prof Tom Curtis, Professor of Environmental Engineering, Newcastle Uni (Chair) Alison Fergusson, Principal Engineer, Water 2020 Programme, Ofwat Eve Germain-Cripps, Wastewater Process Innovation Manager, Thames Water Mat Davis, Technical Adviser, Soil Protection, Environment Agency Thomas Gardiner, Head of Asset Strategy, Northern Ireland Water Nizar Ghazireh, Research and Development, (Aggregates and Asphalt), Tarmac Richard Givens, Lime Technical Consultant, Tarmac Dr Ana Lanham, Lecturer on Water Science and Engineering, Bath University Nevil Muncaster, Director of Asset Management, Yorkshire Water Gordon Reid, Wastewater Service Strategy Manager, Scottish Water Peter Vale, Technical Lead, Innovation, Severn Trent Luke de Vial, Head of Environment and Water Markets, Wessex Water Steve Wilson, Managing Director of Wastewater Services, Dwr Cymru Welsh Water Mark Worsfold, Director of Asset Management, South West Water Peter Vale (Severn Trent) makes a point to the table Nizar Ghazireh of Tarmac has his say at the event