What is sewage primarily composed of?

Sewage is primarily composed of wastewater generated from everyday activities in homes, businesses, and industries. This includes water that has been used for various purposes, such as cooking, cleaning, bathing, and toilet use. When this wastewater flows through plumbing systems, it carries with it organic materials, human waste, food scraps, chemicals from cleaning products, and other pollutants. Understanding the composition of sewage is crucial for effective wastewater treatment processes, which are designed to remove harmful contaminants before the water is released back into the environment or reused.

The other options refer to different types of waste. Solid waste from landfills does not characterize sewage, as it pertains to the disposal of solid materials rather than wastewater. Stormwater runoff from streets is composed mainly of rainwater that picks up debris, pollutants, and sediments from urban surfaces, but this is separate from sewage. Nutrient-rich agricultural runoff, while related to water pollution, involves excess nutrients like nitrogen and phosphorus from fertilizers entering waterways, which is not the same as sewage. Each of these waste types presents unique management challenges, but they do not define the primary composition of sewage.