What is the definition of sewage?

The definition of sewage encompasses a mixture of water and various types of waste materials, primarily human waste, but can also include industrial discharges and stormwater. The correct choice identifies sewage as a liquid that contains solid materials in both suspension and solution, highlighting that it consists of a complex mixture of organic and inorganic substances.

Sewage differs from clean water or clear liquids, as it is not merely a transparent fluid, which would exclude any solid or organic materials present. Sewage is also not an odorless liquid, since it typically possesses a characteristic smell due to decomposing organic matter. Additionally, while sewage may contain nutrients due to organic materials, defining it solely as an odorless and nutrient-containing liquid neglects the critical aspect of solid waste contained within. Finally, describing sewage as non-toxic overlooks the potential presence of harmful pathogens and chemicals, making it an inaccurate depiction of this byproduct.

Thus, the correct definition encapsulates the complex characteristics of sewage, emphasizing its role as a liquid that holds solid waste materials.