Inflow and Infiltration (I&I) occurs when stormwater or groundwater enters sanitary sewer pipes through cracks, faulty manholes, or improper connections. Excessive I&I can overload sewer systems and increase treatment costs.
According to the City of Irving Water Utilities Design Standards, engineers use watertight manholes, sealed pipe joints, and proper utility separation to help minimize these unwanted flows. Reducing I&I also supports regulatory requirements set by the Texas Commission on Environmental Quality (TCEQ), helping protect public health and maintain reliable wastewater service.