Inflow and Infiltration

Inflow and Infiltration (I/I) is rain water and ground water that enter the sanitary sewer through structural defects, storm water pipeline cross connections, and direct connections of sump pumps and drain systems to the sanitary sewer. This clear water does not need to be treated at the wastewater treatment plant, but once it is mixed with household and business wastewater, Cities have no other choice than to treat the combination as sewage. Removing the clear water reduces sewage handling and treatment costs, reduces the potential for sanitary sewer backups into basements, and allows a City to extend the service life of its investments in the collection and treatment systems.

Our experience encompasses collection system investigations, inventories, sump pump inspections, ordinance revisions and public education that work to complete a successful, positive I/I program. Findings are presented with state-of-the-art GIS mapping and databases to aid CMOM utility inventories and capital improvement planning.

WHKS offers professional services in the following areas:

  • Dye Testing
  • Flow Metering Calibration and Installation
  • GIS Database Management
  • Manhole Inspections, Inventory, Analysis
  • Night-time Flow Checks
  • Rainfall Monitoring
  • Smoke Testing
  • Sump Pump Inspections
  • Televising of Sewer Laterals


Project Experience