How does 'inflow' differ from 'infiltration'?

Inflow and infiltration are important concepts in wastewater management, and understanding their distinctions is key to effective system operation. In this context, inflow refers specifically to the excess water that enters a wastewater system from sources such as stormwater drainage, which is generally surface water that directly enters the sewer system during storm events. This may occur through improper connections or openings in the sewer system that allow rainwater to flow in.

On the other hand, infiltration describes the process by which groundwater seeps into the sewer system through cracks, joints, or other defects in the pipes. This water typically comes from underground sources and is separate from surface water runoff associated with rainfall or melting snow.

Understanding these differences is crucial for managing wastewater systems, as excessive inflow can cause treatment plants to exceed capacity and lead to system overflows. Infiltration, while often contributing to excess flow issues, is generally managed differently since it involves groundwater sources. Recognizing that inflow is primarily associated with stormwater is key for wastewater operators aiming to minimize unnecessary flows and enhance the efficiency of wastewater treatment processes.