Incremental energy and carbon savings have been achieved through painstaking attention to the operating efficiency of processes and plant, aided by digitalisation.
And major steps to decarbonisation have been achieved through the systems approach to water resource management.
New farming and land management practices, and the water providers’ use of nature-based solutions, are reducing the amount of treatment needed to bring raw water up to potable standard. Meanwhile, water and environmental regulators permit flexible wastewater discharge standards, based on the quality of the receiving water body and its ecological health.
Effluent is heavily diluted in rivers swelled by winter rain and pollutants are quickly broken down, enabling the water companies to relax the treatment standard, reducing energy use and carbon emissions. The highest treatment standard must be achieved when river flow is low in summer, so as not to harm plant and animal life or pose a risk to river users’ health. Treatment is adjusted in real time, informed by data on pollution load in the incoming wastewater stream, and on the receiving water body.
Nature-based solutions have reduced the need for treatment, saving energy and chemicals. In some locations, this enables water providers to meet increasing demand without building new water treatment facilities, so avoiding capital carbon emissions.