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Saturday, August 12, 2017

Two Reasons for Sewer Backups: Inflow and Infiltration

(Click on the image for the video)
From The Pipeline:
  • Infiltration is "the excess water that sometimes seeps, trickles, or flows into old or damaged collection systems from the surrounding soil. For example, high groundwater or water remaining in the soil after rain or snow often can infiltrate mainline pipes, joints, service laterals, connections, and other parts of a collection system that have deteriorated, cracked, sagged, or collapsed."
  • "What is inflow? Additional unwanted water also can enter collection systems from above-ground sources. During storms or snow thaws, for example, large volumes of water may flow into systems through leaky manhole covers or combined stormwater/wastewater connections. In addition, private residences may have roof, cellar, yard, area, or foundation drains inappropriately connected to sanitary sewers. Any extra water flowing into wastewater collection systems from above ground sources, either intentionally or unintentionally, is referred to as inflow."
  • [Per the video, inflow has an immediate impact on the collection system. Infiltration is slower to impact but continues after the rain stops.]