Water. Desalination + reuse
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10 Interview March 2018 Water. desalination + reuse treatment charges to industry, and to ensure that it's a ord- able," Bell says. The switch is potentially controversial, because it could represent a rise in cost to industry. "In the US, many communities attract industry by pro- viding low sewer rates. So when you have industries that have relied on those low rates for their operations, if there is an increase, it changes their bottom line. So there is a balancing act between making sure that the rates support industry, and ensuring compliance for environmental dis- charge," Bell says. "It is a little bit complicated, and it has required this meeting of the minds of some biochemists and treatment people, along with the • nancial experts." The next step will be for Bell and her counterpart on the financial side to present to Tennessee Chamber of Com- merce and Industry, and the industrial stakeholders in that community. As part of the integration of MWH Global into Stantec, expertise also † ows in the other direction. In one example, a Stantec client who was designing a new building sought a system for water reuse within that building. "We have established practice groups and, as we have begun to create this connectivity of the leadership between these groups, it is beginning to trickle throughout the organisation in the day-to-day work that our sta are doing. It's a big shi‡ , and we're taking it slowly, but the kind of opportunities it brings for sta are pretty exciting," Bell says. Policy expertise The other dynamic is sharing expertise across borders, and the reuse team based out of North America is working as far a• eld as projects in Ankara, Turkey; and in the UK. Bell, who was project manager for developing the US Envi- ronmental Protection Agency (EPA) guidelines on reuse, is well placed to support policy work on UK reuse regulations, which are likely to be developed separately from European Union (EU) rules a‡ er Brexit. "The UK currently has no reg- ulatory guidance on reuse, and though the UK Environment Agency (EA) recently put forward guidance on incorporat- ing reuse into the EU Water Framework Directive on water quality, Brexit is an opportunity to tailor this speci• cally to • t the UK. For colleagues in the UK to have access to my knowledge gained from developing US guidelines, enables us to leapfrog some of the issues that might otherwise be stumbling blocks," Bell says. "In the US, we have examples of reuse all the way from restrictive access irrigation up to direct potable reuse. We want to develop solutions to pro- vide the water quality that matches the end use." Integrated reuse The other big focus for Stantec's water reuse practice is on integrating water reuse in a holistic way as part of the wider picture of water supply planning. This includes identifying alternative treatment processes, and developing big data analytics solutions that are aimed at optimising the e• - ciency of water operations, from managing the source water quality and watershed management, through the water treatment plant operations, to customer billing, wastewater operations, and monitoring the collection systems. "We can start to pull all of those pieces together on a sin- gle dashboard where we have the ability to use that data for decision-support. That's something we are looking at doing utility-wide, as opposed to focusing on a small element of the treatment process, for example," Bell explains. "If we have several water treatment plants in a utility, we might have the opportunity to maximise production from one of the plants, if it's operating more e• ciently, or with a higher water quality than the others." The importance of real-time monitoring, including water quality monitor- ing, in water reuse, includes that it can help to reduce the In potable reuse, absence of the environmental buff er may shorten failure response times and potentially require more stringent effl uent water quality or process monitoring goals. Ongoing research is investigating the effi cacy and reliability of direct potable reuse (DPR) treatment trains to provide the same or higher level of public safety as existing drinking water treatment plants, or indirect potable reuse (IDPR). DPR treatment trains strive to replace the value of the environmental buff er with additional unit processes, and process monitoring, and yet still require engineered storage buff ers. The size of the engineered storage buff er is of considerable concern because of space limitations, inability to obtain permits for reservoirs, and cost. This is required even though elimination of an environmental buff er may actually reduce risks and provide greater control over source water. For example, in January 2014, 4-methylcyclo- hexanemethanol was released into the Elk River in Charleston, West Virginia, US, upstream from the principal intake and treatment and distribution centre, leaving 300,000 residents without access to potable water. In August 2014, the fourth largest city in Ohio, US, was without drinking water due to a cyanobacteria bloom in Lake Erie that released microcystin, a dangerous algal toxin, into water supplies." Kati Bell, water reuse global practice leader, Stantec a higher water quality than the others." The importance Quote, unquote Water storage risks in de facto, or unplanned, water reuse volume of water held in storage (see quote above). "We're trying to reduce the engineered storage bu er, and in order to do that we need to squeeze that response time as much possible, so that we can immediately divert water if it's not of the right quality," Bell explains. In the city of Atlanta, Georgia, Stantec developed an analytics solution to predict when and where a combined sewer over† ow will occur. "This gives the city hours or even days to respond proactively, either by cleaning out a block- age, or addressing another maintenance issue. That has really reduced the number of system outages, and because of the success of that programme, we have a second phase of work extending that into other parts of the utility," Bell says. On an individual plant basis, work is going on to develop digital twin capabilities, enabling Stantec to train operators in appropriate responses to system upsets. The water reuse practice is associated with numerous academic research institutions, including the John Hop- kins School of Public Health, while Bell's own academic research continues apace. Current areas of focus include work on the reliability of direct potable reuse treatment trains to protect public safety; and e orts to discover new treatment solutions for inland water reuse. As connectivity between Stantec's practice leaders grows, and networks within the organisation develop, the opportunity to create more innovate responses to client's challenges is growing all the time.