Researchers in the US say billions could be saved by a switch to green wastewater infrastructure.

The US could save approximately US$15.6 billion and reduce carbon emissions by nearly 30 million tonnes over the next 40 years through the adoption of green wastewater infrastructure, according to a new study.

Braden Limb, a PhD student at the Walter Scott Jr College of Engineering and the study's lead author, highlights the significance of the findings. 

“These findings draw a line in the sand that shows what the potential for adopting green approaches in this space is – both in terms of money saved and total emissions reduced,” Limb says. 

The research underscores the transformative potential of integrating carbon-financing mechanisms with infrastructure development.

Currently, wastewater facilities, especially in the US, contribute significantly to national energy consumption and carbon emissions, accounting for 2 per cent of the nation’s energy usage and 45 million tonnes of CO2 emissions annually. 

Limb says a paradigm shift away from energy-intensive grey infrastructure is needed, pointing to the escalating regulatory standards which could necessitate even greater energy and emissions output in the future.

The study proposes alternative green solutions, such as the construction of wetlands and reforestation, which not only sequester carbon but also address water contamination from non-point sources like agricultural runoff and urban development. 

These nature-based solutions could sequester over 4.2 million tonnes of carbon dioxide annually over four decades and offer significant cost benefits.

Carbon financing emerges as a crucial component of this new approach. 

By selling carbon credits in the open market, companies can fund environmentally positive projects that not only help them meet sustainability goals but also contribute to broader environmental improvements. 

Limb suggested that enhancing existing water market trades and leveraging carbon markets could shift financial incentives in agriculture and water management, potentially generating $679 million in annual revenue.