Infiltration/Inflow; this is the sum of all the extraneous contributions to the collection system.


Internal Condition Grade; numeric criteria applied to visual images of sewers to develop a priority rating based on defects observed.

Idle Time

Lost time when the MTBM is not in operation; not including make-up time or downtime.


Information Guidance Notes; an international reference source for some lining materials.

Ignition Temperature

Temperature at which the vapors emitted from a material will ignite either without exposure to a flame (self-ignition) or when a flame is introduced (flash ignition).