Simplified Conceptual Diagram of Contaminant Loading and Complex Chemical Mixtures in a River

Treated wastewater is water that has been processed through physical, chemical, or biological processes to remove contaminants before being discharged into rivers and other bodies of water. This reuse of treated wastewater is an essential component of the modern water cycle that can help maintain flow of water in rivers during dry periods. Many emerging contaminants, however, are not fully removed by conventional wastewater treatment technologies. These contaminants, once discharged into the environment, may have harmful effects on aquatic life and human health.