Posted on December 2, 2023.

Water and climate are inextricably linked. We see the effects of climate change showing up largely through water, with extreme weather events intensifying in frequency and severity. There is aridification in Western US, droughts across Europe that haven’t been seen in 500 years, heat waves in China and Europe creating supply disruptions, and unprecedented floods in Pakistan covering one-third of the country.

But we aren’t prepared for the massive changes that are happening, which will challenge overburdened infrastructure, water supply and treatment. Decentralised wastewater treatment is one solution that can help us as we are forced to adapt to this new reality. By augmenting or replacing centralised treatment facilities with smaller, decentralised systems we can provide cost-effective sanitation and water in rural areas, as well as reduce strain and build in redundancy to existing infrastructure.

Wastewater's carbon footprint

Water and wastewater utilities account for 5% of global greenhouse gas (GHG) emissions, of which 70% is caused by wastewater treatment. And this doesn’t even consider the 80% of wastewater that is released to the environment without treatment.

According to research by Global Water Intelligence, as we close the gap on sanitation using conventional methods, it will mean an estimated increase in 10% of GHG emissions by the sector. All this, while we must reduce GHG emissions by 45% in 2030 relative to 2005 and achieve net-zero by 2050.

Corporations have an important role to play in addressing both climate and water, as they are large users and emitters. Most large companies have realised the importance of both water and GHG reduction on their core business and are taking steps to improve environmental performance.

Over 1,000 companies have set out plans for achieving net-zero GHG emissions, including many that are setting plans for Scope 3 emissions (those associated with product use and supply chains). The leaders in this area are incorporating it into all aspects of business strategy, recognising that without a healthy environment, they won’t have a healthy business.

The challenge that CEOs face is not in setting targets, but in achieving them. According to a recent article in the Harvard Business Review based on a survey of over 400 C-level executives, 59% don’t have a firm grasp on the financial risks and opportunity posed by climate, and 54% have not integrated Environmental, Social, and Governance (ESG) factors into capital allocation decisions.

Decentralised wastewater treatment

Additionally, wastewater is never included at the C-suite discussions on climate, and the untapped value that wastewater holds has been overlooked in most companies’ ESG plans. Wastewater has enough energy potential that its treatment can be carbon-neutral, but companies haven’t invested in the technology to harness this and are instead discharging their waste to the downstream utility, landfilling or incinerating the sludge.

When it is discharged to the sewer, centralised wastewater treatment relies heavily on aerobic systems, meaning that air is blown into the wastewater, which requires large amounts of energy and generates high volumes of sludge. The sludge is landfilled, which breaks down into methane, a GHG 84 times more potent than CO2.

Onsite, distributed treatment, for industrial companies provides a way to tap into this value by removing the bulk of organic material at the point of use. This can mitigate up to 90% of GHG emissions at the downstream utility; and by treating at the point source, the water can be reused onsite for applications that require lower-quality water (such as cooling towers, boilers and washing).

Climate adaption and building resilience

The benefits of onsite treatment include reduced demand for freshwater, which can alleviate water scarcity. Onsite treatment reduces the energy requirements to transport and treat and enables higher quality water for discharge. It also contributes to risk reduction in scenarios such as discharge permit reductions, limitations on water use or negative public perception related to water use and discharges.

In the longer term, these benefits extend to increased resilience and adaptation. Currently, 2.7 billion people face water scarcity for at least one month per year, and this is only going to get worse. As climate change intensifies extreme weather events, water infrastructure will not be able to reliably provide water and sanitation services. We have seen hurricanes destroying wastewater treatment plants, disrupted power grids interfering with water supply, and mass migrations and refugee camps demanding access to infrastructure that doesn’t exist.

Sustainable Development Goals

Access to sanitation and clean water is the foundation for solving all of the other Sustainable Development Goals (SDG), including climate change, food security, and gender equity. The lack of access to clean water is felt disproportionately in developing countries, low-income, ethnic minority communities and by women or girls. For women and girls, this means increased safety and education, as they are the ones tasked with getting water and are at risk for sexual assault in public bathrooms.

For corporations that operate in these communities, providing access to sanitation is important to maintain employee well-being and social license to operate. A decentralised, off-sewer and off-energy grid option helps to provide resilience to quickly respond to events that challenge or damage our existing infrastructure.

While wastewater is always complex, and almost never a one-size fits all approach, we need to rethink its contribution to a healthy watershed, GHG emissions and resilience. Rather than viewing it as a problem to be managed, we need to view it as a solution to some of our biggest environmental and humanitarian challenges. This requires a willingness to adopt new technologies for monitoring and treatment. Some will likely fail, but the immediate action required to solve these problems justify the risk.

Source: www.weforum.org