GWWI WEF Wastewater Treatment Fundamentals 2026 – 400 Free Practice Questions to Pass the Exam

Stormwater inflow is a key factor that can dilute influent concentrations in wastewater treatment facilities. When heavy rainfall occurs, stormwater can overwhelm the sewage system, leading to a mixture of storm runoff and wastewater. This influx of additional water reduces the concentration of pollutants in the influent, as the contaminants become dispersed in a larger volume of water. This dilution can affect the treatment process and the performance of the facility, as it alters the hydraulic loading and the concentration of waste materials that need to be treated.

In contrast, increased temperature affects the kinetics of biological processes but does not inherently dilute the influent. Inadequate filtration primarily relates to the removal of solids and does not involve the introduction of additional water that would dilute concentrations. Microbial die-off pertains to the reduction of microorganisms in a treatment system and similarly does not introduce more water, thus it does not lead to dilution of influent concentrations.