Program Background

The goal of the inflow and infiltration (I/I) program is to identify and reduce sources of I/I in the sanitary sewer system.   I/I is clear stormwater and groundwater that enter the sewer system that should otherwise be collected by a system that allows for the water to infiltrate back into the ground locally.  I/I must be removed at the source, before it enters the sewer system, otherwise the clear stormwater and groundwater is conveyed to the Wastewater Treatment Facility (WWTF) where it is processed and treated as wastewater resulting in an overall reduction in sewer system capacity and increased operating costs for treatment.

The Town uses multiple inspection methods to identify I/I in the sewer system, and sources of I/I that are found during these inspections are prioritized for repair.  Repairs to reduce I/I include sealing leaking pipe joints, lining pipes with cracks or holes, and lining leaking manholes with cement to stop the infiltration of groundwater.  Whenever feasible, the Town attempts to fix I/I sources using trenchless methods, meaning excavation is not required to perform the repairs.  When these methods are not feasible, excavation of the ground is required so the pipes can be replaced.