Which of the following best describes the definition of wastewater?

The definition of wastewater is best described as water that contains contaminants from various sources. Wastewater encompasses a wide range of water types, including water that has been affected by human activity, such as household output (sinks, toilets, and showers), industrial processes, and stormwater runoff. The presence of these contaminants, which may include organic matter, chemicals, pathogens, and other pollutants, highlights the need for treatment before the water can be safely released back into the environment or reused.

Other choices do not accurately capture the essence of wastewater. Unfiltered surface water does not necessarily include the organic and inorganic contaminants associated with wastewater. Clean and safe drinking water is, by definition, free from contaminants and unsuitable as a descriptor for wastewater. Lastly, while rainwater collected from rooftops can contain some pollutants, it is not classified as wastewater unless it carries contaminants from polluted surfaces. Therefore, option C comprehensively describes wastewater as it integrates the broad range of potential pollutants that affect water quality.