What is I&I?
Inflow is a direct connection of “clear” water (rain/storm water) into the wastewater (sanitary sewer) collection system. Infiltration is an indirect connection of “clear” water to the wastewater (sanitary sewer) system. Inflow is by far the larger problem of the two and occurs in direct proportion to rainfall. Inflow is most often the result of improperly installed sump pumps (used by many homeowners to keep groundwater out of basements), roof downspouts, and foundation drains illegally connected to the City’s sanitary sewer system. Sump pumps are also sometimes illegally connected to the sanitary sewer system via a hose leading from the sump to a laundry tub or floor drain. Infiltration occurs when groundwater seeps into sewer pipes through cracks, leaky joints or deteriorated manholes.