Wastewater contains about five times more energy than is needed for its treatment, yet the total annual energy use by municipal wastewater treatment systems in the U.S. is approximately 30 billion kWh. Resource recovery expands the focus of wastewater treatment from maintaining water quality protection in the most cost—effective manner to include managing the wastewater stream to extract valuable resources including nutrients, energy, and water.
Increasing population pressures, climate change, aging infrastructure, and funding limitations strain water resources and require sustainable resource management solutions and movement toward a circular economy over the next century. Nutrients such as nitrogen and phosphorus can be used in reclaimed water for irrigation or recovered in biosolids and sold as fertilizer. Energy can be recovered in the form of biogas as fuel and in heat recovery. Water has been recycled by the earth for millions of years. Water reclaimed from treatment processes can be used for cooling and industrial uses, irrigation, or with treatment tailored to the quality requirements of the planned reuse as drinking water, thereby saving energy and resources.
As population, climate change, and funding strains begin to further affect water resource recovery facilities, they must operate in a way that allows them to continue to sustainably provide their essential service. No longer disposal facilities, they must transform into resource recovery facilities, recovering nutrients, producing fit for purpose water and reducing energy demands. The Baseline Data to Establish the Current Amount of Resource Recovery from WRRFs report established a baseline for current water reuse, biosolids, nitrogen, phosphorus and energy operations in the United States which are used to establish goals for WRRFs to strive towards.