Get smart with data to improve water quality

Water companies are under growing pressure to reduce levels of sewage discharged into rivers and the sea. Smart wastewater networks that make better use of data will help them to improve their performance and protect the aquatic environment, says Tony Smithson.

The water industry’s impact on the environment has never been under such close scrutiny by regulators, the media and consumers as it is now.

In the UK, record fines have been imposed on water companies for sewage spills, leading to a spate of negative headlines and heightened public concerns.

An increasingly ageing asset base, straining to meet the demands placed on it by population growth, is leading to more system failures, increasing the frequency and volume of unregulated discharges. The situation is made worse by sewer blockages caused by people continuing to flush wet wipes and other non-flushable items down the toilet, and pour oils and fats down drains.

All these pressures are being compounded by climate change.

In 2020, water companies discharged sewage from storm overflows into England’s rivers more than 400,000 times, according to the Environment Agency. Its data highlights how often utilities make use of these overflows, as they are permitted, to protect homes and businesses from flooding in extreme weather. This will only get worse with higher rainfall due to our changing climate.

Big data has revealed the extent of the problem. It can also help us to solve it. The more information we have on system performance, water quality and the correlation with overflows within a network, the more we can mitigate and prevent pollution from both regulated and unregulated sewer discharges.

Digital twins

Historically, investigating watercourse quality and the geographic distribution of water quality has centred around working with physical samples. Although this analysis has aided decision-making, these retrospective decisions are often too late to do much good.

Dynamic systems such as water and wastewater networks require dynamic decision support information, based on live data from multiple sources. We can do this by enhancing physical infrastructure with digital technology to create smart wastewater networks.

A key element of this is the concept of a digital twin – an accurate model of an asset or system that is continuously updated 24/7 by performance data from the physical twin via live inputs from sensors.

By visualising the performance of assets in real time, digital twins will improve operational efficiency and support the transition to more predictive maintenance regimes. Operators will be able to model scenarios to pinpoint potential faults before they occur and prevent pollution incidents, and if failures do occur, respond more swiftly to reduce any risk to public health.

Better use of data can unlock added capacity from existing assets and increase their resilience, extending operational life. More accurate measurement of performance will give greater insight into when assets should be upgraded or replaced, targeting investment where it is needed most.

Predictive modelling

The World Health Organization, in its newly published Guidelines on Recreational Water Quality, highlights the importance of predictive models to improve operational monitoring and provide timely information to the public on recreational water quality. It cites Safeswim, developed by Mott MacDonald for Auckland Council, as an exemplar project.

Improving infrastructure to prevent pollution is Auckland’s long-term goal, but it required a more immediate fix: people needed to know when and where the water was safe. Safeswim tells you just that.

Test results on water quality supplied by monitors installed at 10 key points across the city’s wastewater network, combined with real-time tidal, river hydraulics and meteorological data, is fed into Moata, our smart infrastructure platform. Moata analyses the inputs to predict when and where sewer overflows will occur.

This data is shared with the public via the Safeswim app which provide up-to-the-minute bulletins and maps on swimming conditions at over 115 beaches. An independent audit found Safeswim’s water quality predictions to be 89% accurate.

It has not only enabled water users to make informed decisions about where to swim and surf, it has strengthened trust and opened dialogue between the council and the local population. This has increased people’s awareness about the causes and effects of water pollution, and their willingness to pay for improvements.

Investment in digital solutions will assist the industry to comply with regulations on transparent reporting. In the UK, the latest amendments to the Environment Bill place duties on water companies not just to reduce sewage discharges from overflows but to monitor and publish data on the impacts of discharges on water quality.

Greater transparency and communication will promote collaboration between service providers, stakeholders and the public. This will support a systems-based, catchment-wide approach to water management so that resources, demand, assets and risks are managed holistically, including efforts to drive up water quality standards.

Exponential change

While the physical principles of water and wastewater network design and operation have not changed significantly over the past 100 years, the methods and systems available to capture, analyse and gain insights from data are advancing exponentially.

Smart infrastructure, artificial intelligence and machine learning are transforming our industry. The development of digital twins like Moata, now used by utilities and local authorities around the world to monitor their networks, is disrupting asset delivery, operation and management.

This is happening as people are reconnecting with their natural surroundings after living in lockdown during the pandemic. Watersports such as wild swimming are becoming more popular. This is raising expectations of the industry’s environmental performance and how well it fulfils its duty of care to society and the planet.

Data can play a role here, too, by encouraging investment that yields a social return, not just a financial one. Data can pinpoint where upgrades or new assets will create opportunities to deliver positive social outcomes that make a lasting difference to communities, from improved public health and biodiversity to greater access and enjoyment of natural amenities.

By improving data capture, management and analysis to improve the efficiency and resilience of wastewater networks, we will be able to enhance not just the environment but people’s quality of life for generations.