Impervious

Impenetrable. Completely resisting entrance of liquids.

In situ

Describes work on site; in the original place. For example, in situ concrete would differentiate cast in place concrete from precast concrete.

In-line Microtunneling

A method of replacing an existing pipe by filling the pipe with flowable fill to prevent fluid loss and then excavating the entire pipe and surrounding ground with an MTBM for a new installation.

In-Line/On-Line Replacement

The breaking out of an existing pipeline and the installation of a new service on the same line. See Replacement.

Inadvertent Contact

Contact between a person and a hazard resulting from the person’s unplanned actions during normal operation or servicing of the machine.