Which of the following is a key factor in determining the health of treated wastewater?

The health of treated wastewater is fundamentally assessed by the removal percentages of organic matter. This metric indicates how effectively the treatment process has removed contaminants that can negatively impact the environment and human health. High levels of organic matter in wastewater can lead to oxygen depletion in receiving water bodies, potentially harming aquatic life and disrupting ecosystem balance.

While factors like the color of water, the presence of pathogens, and the temperature of the effluent can provide additional insights into water quality, they are not as central to the core assessment of wastewater health as the removal of organic matter. Color may indicate the presence of certain substances but does not directly correlate with health risk, temperature is more indicative of physical conditions affecting treatment processes rather than health status, and while the presence of pathogens is certainly a concern, it is often more of a direct consequence of insufficient organic matter removal rather than a primary measure of health in treated wastewater. Therefore, focusing on the removal percentages of organic matter provides a direct evaluation of treatment effectiveness and the overall safety of the water for discharge or reuse.