Inflow Infiltration

Also referred to as INI, (1) The seepage of stormwater or groundwater into an OWTS or other sewage system through cracks, pipe joints, etc. This is one of the major issues with the collection systems of central treatment facilities.(2) The downward entry of water into the immediate surface of soil or other material, as distinct from percolation, which is movement of water through soil layers or material. <