Water & Wastewater Treatment Magazine
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www.wwtonline.co.uk | WWT | AUGUST 2019 | 13 In Focus: Abstraction Ninety-two per cent of the water supply in Perth came from dams in 1958, with the remainder from ground- water sources, but the situation had completely changed by 2014: water from dams was supplying just 7 per cent and, while groundwater abstrac- tion rose to 42 per cent, desalination provided 50 per cent, with 'advanced water recycling' delivering the remain- ing 1 per cent. "They're taking 7 per cent from dams because their rainfall isn't suffi- cient to refill them," he says. "They've got some desalination, some treated effluent back into the groundwater and then taken out lower down, and they've done a lot of demand manage- ment. They've really reduced their primary abstraction from the environ- ment." Since desalination functions best when run constantly and carries its own environmental impacts, it is not an automatic, simple solution for the UK, but WRSE is exploring a variety of options. The organisation is actively undertaking site visits to explore whether emerging technology, such as graphene, is sufficiently advanced to progress planning for the world's first at-scale trial. Wastewater recycling is another hugely promising opportunity, al- though there are obvious concerns with public perception. "If we can recycle and recirculate water within the system, that cre- ates an incredible opportunity for the future," Bishop says. "What we saw in Australia was fascinating – during the millen- nial drought, they started building a series of treatment plants to reuse wastewater and it went pretty well in most places, but in some places a few politicians started using the term 'poo water', which had significant impacts on public acceptability." Orange County, California, has succeeded in reusing wastewater to top up water supplies, with up to 50 million gallons a day delivered into a groundwater replenishment system. To overcome the barrier around public perception, they spent $1 million on focus groups before building the plant in 2008 and have continued to run daily tours. "I believe it is possible to shift public opinion and acceptability in the long term," Bishop says. "Even if we spent, say, £10 million on engage- ment, it would be money well spent compared to the infrastructure we'd have to build to create alternative – and less sustainable and resilient – options. "We're also quite rightly looking at building transfers from areas of surplus to areas of deficit to balance supplies, including from the north west to the south east, but these op- tions also require careful and objective assessment – not only are the carbon costs significant but, if we remember the summer of 2017, it showed us that the north of England can be equally prone to drought." He suggests the Chelmsford scheme run by Essex & Suffolk Water, which sees wastewater treated to a high environmental standard and then ab- stracted downstream, might represent a successful blueprint. "The Chelmsford scheme seems to work really well – everyone's very happy," he says. "That only goes in a relatively short section of river, but it's indirect and people can live with that." The future Last year, the EA noted that while high winter river flows have increased over the past three decades, there is not yet a clear trend in droughts and that, even looking back to the mid-18th cen- tury, summer rainfall has decreased only slightly. Even so, the lack of rainfall over recent years shows the potential threat cannot be ignored, and popu- lation growth threatens to exacerbate the situation. As new technologies emerge and efforts to cut carbon ramp up, there is likely to be an increased focus on demand management , leakage reduction and alternative sources of supply, which – allied to an im- proved understand of abstraction impacts – could provide a platform for a sustainable approach that will serve our water companies long into the future. WATER RESOURCES • REGULATION REFORM The Environment Agency has been working for several years to reform the abstraction licensing system, which was introduced in the 1960s. While the EA does have the ability to withdraw abstraction licences, that generally covers brief periods when the environmental problems are particularly acute – most abstractions are permitted to take place at the same level throughout the year with no link to environ- mental status. Giving evidence as part of the Government's Regulation of the Water Industry inquiry last summer, EA chief executive Sir James Bevan said the current system was designed for a period where there was no water stress and far fewer people, adding: "Many of the abstraction licences have no limits on the amount of water that you can take out of the ground, and many of those abstraction licences are very long-term." As part of the Water Act 2014, options for 'water shares' were created, which would have meant that, for example, rather than providing a licence for 10 megalitres per day, the licence would allow for 10 per cent of sustainable abstraction, which would alter dynamically in line with the circumstances. That option has yet to be utilised but, during the prolonged dry spell in 2018, the EA trialled a number of flexible approaches, such as rapid trading and abstracting at high flows. The Government's abstraction plan, published in 2017, also set out its intention to use existing regulatory powers and approaches to address unsustainable abstraction and deliver on its improvement targets for surface water and groundwater bodies by 2021. "We are committed to reforming water abstraction licencing and are taking action to prevent unsustainable abstraction which may damage our precious wildlife and ecosys- tems," an EA spokesperson says. "Since 2008, we've made changes to over 282 abstraction licences, ensuring that there is sufficient water for people while preventing over 40 billion litres of water per year being removed from the environment. This includes 99 changes to water company licences since 2014, returning 15 billion litres of water to the environment. "We are also working with water companies and Ofwat to ensure that the water compa- nies' long-term plans include action to address growing pressures on water supply." While legislative measures may be brought in if the intended environmental im- provements fail to transpire by 2021, Bevan has expressed confidence that the water companies understand the importance of reducing unsustainable abstraction, saying he "would rather try to reach voluntary agreements than wield a big stick". In May, Defra told Parliament that EA is on track to meet the targets of the water abstraction plan.