What is termed as inflow in the context of wastewater collection systems?

Inflow, in the context of wastewater collection systems, specifically refers to the unnecessary entry of water into the sewer system from sources that are not part of the regular wastewater flow. This includes water that enters through non-regular sources, such as yard drains, roof downspouts, and other similar connections that lead directly into the sewer system. This additional water can significantly increase the volume of water passing through the treatment system, impacting the treatment process and potentially leading to overload conditions.

Understanding inflow is essential for managing and maintaining efficient wastewater collection systems, as it differs from other forms of water entry, such as infiltration, which pertains to groundwater entering through damaged sewer pipes. Recognizing these distinctions helps in implementing strategies for reducing excess water in the system and ensuring that treatment facilities operate optimally.