How the water sector is using innovative tech to become more resilient and sustainable

During weeks of drought across Europe this summer, water levels dropped low enough to expose an ancient message, "if you see me, then weep." The inscription on a rock in the Elbe River, near the northern Czech town of Děčín, was a timely reminder as rivers ran dry.

In the US, waters along the Mississippi receded to such a low level they revealed a ferry, likely sunk around the turn of the 19^th century, near Baton Rouge. These are only two indicators in a year that left us in little doubt that climate change is wreaking havoc on water and how we manage it.

Many communities are facing up to the urgent issue of ageing infrastructure that is ill-equipped to deal with a harsher climate. They are confronting the economic anxiety of major upgrades by rethinking the status quo and leaning into technology to deliver more water sustainability.

The idea is to achieve double bottom-line results, a net-zero sector that is more resilient and efficient. Resilience will prolong the life of ageing, sometimes ailing, infrastructure. Sustainability will tackle the problem at source.

As water utilities illustrate what is possible through technology and data-driven decision-making, the sector can be a powerful example for other industries looking to pick up the pace in the race to net-zero.

The water sector does essential work for communities. However, it is energy intensive. Water and wastewater infrastructure is a significant greenhouse gas (GHG) contributor – making up approximately 2% of global GHG emissions, on par with the shipping industry. This means water is contributing to a warming world.

While economy-wide net-zero ambitions continue to scale up, progress on decarbonization has declined over the past 12 months, according to PwC’s recent Net Zero Economy Index 2022. Despite the rise in rhetoric, last year's global rate of decarbonization was at its lowest level for more than a decade. Our approach needs to have substance and urgency.

Many water utilities are making significant strides towards net-zero while delivering more efficiently for their communities. They are achieving this by leaning into innovative tech and approaches to achieve the double bottom line of being more resilient and sustainable.

Take the city of South Bend, Indiana, US. A few years ago, every storm put the city's ageing sewer system under major pressure to deal with excess discharge. In 2012, it was looking at $713 million in capital improvements, plus financing costs – a massive investment for a municipality with a population of just over 100,000.

Instead, it took a more efficient approach. South Bend used smart sensors and actuators to trade available capacity in the sewer system in real time. Akin to an underground stock market, it traded space to push water to under-utilized parts of the network during storms.

The programme eliminated dry weather overflows and reduced combined sewer overflow volumes by more than 80%, or about a billion gallons a year. Not only did this work save the utility millions of dollars, but it also avoided the construction of grey infrastructure saving tons of embodied carbon.

For water and wastewater utilities, the climate crisis comes on top of more familiar challenges: ageing networks, rising populations, shrinking fresh water supplies, evolving regulations, and tightening budgets.

We cannot just turn off the tap. Utilities do an exceptional job providing essential services to their communities. This must continue without interruption as climate change makes that job more difficult.

Prioritizing emissions reduction does not require a fundamental shift in how the water sector does business. Previous research found that around half the wastewater sector's energy-related emissions can be abated with existing technology. About 95% of this impact is achievable at zero or negative cost.

Take digital twins, which can optimize operations, resulting in significant drops in energy consumption. In Cuxhaven, Germany, EWE WASSER GmbH runs a large treatment plant that can treat wastewater for the equivalent of 400,000 people.

To become more efficient, Cuxhaven first had to gain a better understanding of the performance of the processes involved. Virtual sensors estimate the incoming carbon, nitrogen, and phosphorous loads. With a real-time digital twin of the entire plant, it was then possible to optimize aeration and chemical inputs at each point of the process.

Armed with this, the Cuxhaven treatment plant reduced aeration energy use by 30%, or 1.1 million kilowatt hours (kWh) annually — enough energy to power 275 homes for one year.

By taking steps now, we can address both operational efficiency and costs and climate change mitigation. Resilience will prolong the life of aging, sometimes ailing, infrastructure. Sustainability will tackle the problem at source.

As temperatures rise, these results cannot come quickly enough.