What parameters define residential strength effluent?

The definition of residential strength effluent is commonly established based on specific parameters of biochemical oxygen demand (BOD5) and total suspended solids (TSS). In this context, the correct parameters for residential strength effluent are a BOD5 of 300 mg/l and a TSS of 300 mg/l.

BOD5 measures the amount of oxygen required by microorganisms to break down organic material in water over a period of five days. A BOD5 level of 300 mg/l indicates a moderate level of organic pollution that is typical of residential wastewater. TSS, which quantifies the concentration of solids suspended in water, at the same level of 300 mg/l, suggests that the effluent contains a significant amount of sediment and particulate matter that arises from typical household activities.

The parameters selected reflect the characteristics of domestic sewage, providing an appropriate benchmark for estimating the treatment needs and the potential impact on the environment when this effluent is discharged into treatment facilities or receiving waters. In contrast, other combinations provided in the choices either exceed or fall below the values that effectively represent residential effluent strength, making them less applicable within this context.