Infiltration and exfiltration refer to what types of flow in sewer systems?

Infiltration and exfiltration in sewer systems specifically refer to the flow of water. Infiltration describes the process where groundwater or surface water enters the sewer system through cracks, joints, or leaks in the pipes. This additional water can lead to increased flow rates in the system, which can strain the capacity of wastewater treatment facilities and impact overall operations.

Exfiltration, on the other hand, refers to the process where wastewater or treated water leaves the sewer system and enters the surrounding soil or groundwater, typically when the system is improperly sealed or has defects. This flow is important to monitor, as it can lead to environmental contamination if untreated wastewater seeps out.

While the concepts of infiltration and exfiltration can sometimes involve stormwater or even air in different contexts, in sewer systems, they primarily pertain to the movement of water entering and exiting the pipes. Thus, the answer aligns with the fundamental definitions of these terms in relation to water flow in sewer systems.